Netter Concise Orthopaedic Anatomy 2nd Edition

7 Pelvis • MUSCLES Transverse Section: Pubic Crest, Femoral Heads, Coccyx Superior portion of pubic symphysis Interior of urinary bladder Co Spermatic cord Adductor longus muscle Beginning of urethra Body of pubis Prostate gland with prostatic urethra Pectineus muscle Psoas muscle and tendon Femoral vein Iliacus muscle Femoral artery Head of femur Femoral nerve Neck of femur Sartorius muscle Gluteus medius Iliopsoas muscle muscle Gluteus Rectus femori minimus muscle tendon Greater Tensor trochanter fasciae latae muscle Inferior Gluteus gemellus medius muscle muscle Right sciatic nerve Obturator Gluteus maximus muscle artery, vein, and nerve Obturator internus muscle Acetabular fossa Sacrotuberous ligament Lunate (articular) Ejaculatory ducts surface of acetabulum Perineal flexure (termination of Left sciatic nerve rectum, beginning of anal canal) Internal pudendal artery and vein Tip of coccyx Pudendal nerve Fat body of ischioanal fossa Levator ani muscle (puborectalis) MRI pelvis Femoral artery Adductor longus Sartorius Anterior wall Tensor fasciae latae Femoral Gluteus head medius Obturator Rectus internus femoris Posterior Iliopsoas wall Urinary Gluteus bladder maximus Coccyx 240 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

NERVES • Pelvis 7 Diaphragm (cut) L1 White and gray rami Subcostal nerve (T12) communicantes L2 Subcostal nerve (T12) Sympathetic trunk L3 Iliohypogastric nerve Iliohypogastric nerve L4 Ilioinguinal nerve Transversus abdominis Ilioinguinal nerve muscle Genitofemoral nerve (cut) Quadratus lumborum muscle Psoas major muscle Lateral cutaneous nerve of thigh Gray rami communicantes Genitofemoral nerve Femoral nerve Obturator nerve Iliacus muscle Psoas major muscle (cut) Lumbosacral trunks Lateral cutaneous nerve of thigh Inguinal ligament (Poupart) Femoral nerve Genital branch and Femoral branch of genitofemoral nerve Obturator nerve LUMBAR PLEXUS Schema T12 Subcostal nerve (T12) L1 Lumbar plexus comprises the ventral White and gray rami rami of L1-L4. Two divisions: anterior communicantes L2 (innervates flexors), posterior (exten- Ventral sors). Plexus formed within the psoas Iliohypogastric nerve rami of muscle. Ilioinguinal nerve L3 spinal Anterior Division nerves Genitofemoral nerve Subcostal (T12): Inferior to 12th rib L4 Lateral femoral Sensory: Subxyphoid region cutaneous nerve L5 Motor: None Gray rami communicantes Lumbosacral trunk Iliohypogastric (L1): Under psoas, pierces abdominal muscles Muscular branches to psoas and iliacus Sensory: Above pubis muscles Motor: Posterolateral buttocks Transversus abdominis Femoral nerve Internal oblique Accessory obturator nerve (often absent) Obturator nerve Ilioinguinal (L1): Under psoas, pierces abdominal muscles Obturator (L2-4): Exits via obturator canal, splits into ant. Sensory: Inguinal region, anterosuperior thigh & post. division (can be injured by retractors placed Motor: None behind the transverse acetabular ligament [TAL]) Genitofemoral(L1-2): Pierces psoas lies on anterior Sensory: Inferomedial thigh via cut. br. of obturator n. surface of psoas muscle Motor: External oblique Sensory Scrotum or labia majora Motor: Cremaster Obturator externus (posterior division) Accessory Obturator (L2-4): Inconsistent Sensory: None Motor: Psoas Posterior Division Lateral Femoral Cutaneous (FFCN) (L2-3): runs on ilia- Femoral (L2-4): Lies between psoas major and iliacus cus, crosses inferior to ASIS (can be compressed there: meralgia paresthetica) Sensory: None (in pelvis) Motor: Psoas Sensory: None (in pelvis) Iliacus Motor: None Pectineus NETTER’S CONCISE ORTHOPAEDIC ANATOMY 241

7 Pelvis • NERVES Schema L4 Lumbosacral trunk Anterior division L5 Posterior division Gray rami communicantes Superior gluteal nerve S1 Inferior gluteal nerve S2 Pelvic splanchnic nerves (parasympathetic to Nerve to piriformis inferior hypogastric [pelvic] plexis) Tibial nerve S3 Sciatic nerve Common fibular S4 (peroneal) nerve S5 Coccygeal nerve Nerve to quadratus femoris (and inferior gemellus) Perineal branch of 4th sacral nerve Nerve to obturator internus (and superior gemellus) Nerve to levator ani and coccygeus (ischiococcygeus) muscles Lumbosacral trunk Pudendal nerve Psoas major muscle Perforating cutaneous nerve Superior gluteal artery and nerve Posterior femoral cutaneous nerve Obturator nerve Iliacus muscle L5 Sympathetic trunk Inferior gluteal artery L4 Gray rami communicantes Nerve to quadratus femoris Pelvic splanchnic nerves (cut) Internal pudendal artery S1 (parasympathetic to inferior Nerve to obturator internus S2 hypogastric [pelvic] plexus) Pudendal nerve S3 Piriformis muscle Obturator internus muscle Superior pubic ramus S4 Piriformis muscle S5 Coccygeus (ischiococcygeus) muscle Nerve to levator ani muscle Co Levator ani muscle Sacral splanchnic nerves (cut) (sympathetic to inferior Topography: medial and slightly hypogastric [pelvic] plexus) anterior view of hemisected pelvis LUMBOSACRAL PLEXUS Lumbosacral plexus comprises the ventral rami of L4-S3(4). Two divisions: Anterior (innervates flexors), posterior (exten- sors). Plexus lies on anterior piriformis muscle. Anterior Division Nerve to quadratus femoris (L4-S1): Exits greater Pudendal (S2-4): Exits greater then re-enters pelvis through sciatic foramen lesser sciatic foramen Sensory: None Sensory: Perineum: Motor: Quadratus femoris via perineal nerve (scrotal/labial br.) via inferior rectal nerve Inferior gemelli via dorsal nerve to penis/clitoris Nerve to obturator internus (L5-S2): Exits greater Motor: Bulbospongiosus: perineal nerve sciatic foramen Ischiocavernosus: perineal nerve Urethral sphincter: perineal nerve Sensory: None Urogenital diaphragm: perineal nerve Motor: Obturator internus Sphincter ani externus: inferior rectal nerve Superior gemelli Nerve to coccygeus (S3-4): directly innervates muscle Sensory: None Motor: Coccygeus Levator ani 242 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

NERVES • Pelvis 7 Gluteus maximus muscle (cut) Iliac crest Superior gluteal nerve Gluteus medius muscle (cut) Gluteus minimus muscle Sciatic nerve Piriformis muscle Inferior gluteal nerve Superior gemellus muscle Posterior cutaneous nerve of thigh Tensor fasciae latae muscle Nerve to obturator internus Gluteus medius muscle (cut) (and superior gemellus) Obturator internus muscle Pudendal nerve Nerve to quadratus Ischial spine femoris (and inferior gemellus) supplying Sacrospinous ligament articular branch to hip joint Perforating cutaneous nerve Sacrotuberous ligament Inferior anal (rectal) nerve Greater trochanter of femur Dorsal nerve of Intertrochanteric crest penis/clitoris Perineal nerve Inferior gemellus muscle Quadratus femoris muscle Posterior scrotal/ Gluteus maximus muscle (cut) labial nerves Sciatic nerve Perineal branches of Posterior cutaneous nerve of thigh posterior cutaneous Inferior cluneal nerves nerve of thigh Ischial tuberosity Semitendinosus muscle Biceps femoris muscle (long head) (covers semimembranosus muscle) LUMBOSACRAL PLEXUS Posterior Division Both Divisions Superior Gluteal (L4-S1): Exits greater sciatic foramen Posterior Femoral Cutaneous (S1-S3): Exits via greater above the piriformis sciatic foramen, under piriformis, medial to sciatic Sensory: None nerve Motor: Gluteus medius Sensory: Inferior buttocks: via inferior cluneal nerves Gluteus minimus Posterior perineum: perineal branches Tensor fasciae latae Posterior thigh (see Chapter 8) Inferior Gluteal (L5-S2): Exits greater sciatic foramen Motor: None Sensory: None Motor: Gluteus maximus Sciatic (L4-S3): Largest nerve in body. Two components: tibial (ant. division) and peroneal (post. division). Exits Nerve to Piriformis (S2): Directly innervates muscle greater sciatic foramen under piriformis. Anatomic vari- Sensory: None ants include exiting through or above piriformis. Re- Motor: Piriformis flecting short ERs will protect sciatic in posterior ap- proach to hip. Sensory: None (in pelvis; see Chapters 8-10) Motor: None (in pelvis; see Chapters 8-10) Other Nerves (Nonplexus) Superior Cluneal (L1-3): Branches of dorsal rami. Medial Cluneal (S1-3): Branches of dorsal rami Sensory: Superior 2⁄3 of buttocks Sensory: Sacral and medial buttocks • Piriformis muscle is the landmark in gluteal region. Most nerves exit inferior to it. POP’S IQ is a mnemonic: Pudendal, N. to Obturator internus, Posterior cutaneous, Sciatic, Inferior gluteal, N. to Quadratus femoris. NETTER’S CONCISE ORTHOPAEDIC ANATOMY 243

7 Pelvis • ARTERIES Abdominal aorta Internal iliac artery Posterior division Median sacral artery Right Common iliac Anterior division Left arteries Iliolumbar artery External iliac artery Umbilical artery (patent part) Lateral sacral arteries Obturator artery Middle rectal artery Superior Uterine artery gluteal artery Vaginal artery Inferior vesical artery Piriformis muscle Superior vesical arteries Inferior Medial umbilical ligament gluteal artery (occluded part of umbilical artery) Internal pudendal artery Coccygeus Pubic symphysis (ischiococcygeus) muscle Sagittal section Sacrotuberous ligament Obturator fascia (of obturator internus muscle) Internal pudendal artery in pudendal canal (Alcock’s) Levator ani muscle (cut edge) ARTERY COURSE COMMENT/SUPPLY Common iliacs Median sacral AORTA Internal iliac External iliac Branch at L4, run along anterior spine Blood supply to pelvis & lower extremities Obturator Descends along anterior spine & sacrum Anastomoses with lateral sacral arteries Inferior gluteal Multiple visceral COMMON ILIAC ARTERY branches Under ureter toward sacrum, then divides Supplies most of pelvis & pelvic organs Divides into anterior & posterior divisions Superior gluteal Iliolumbar On ant. surface of psoas to inguinal ligament Does not supply much of the pelvis Lateral sacral INTERNAL ILIAC Anterior Division Through obturator foramen w/obturator nerve Fovea artery (ligamentum teres) branches Exits greater sciatic foramen under piriformis Supplies gluteus maximus muscle Umbilical Supplies bladder (via sup. vesical arteries) Uterine/vaginal (females) Supplies uterus & vagina (via vaginal br.) Inferior vesical (males) Supplies bladder, prostate, ductus deferens Middle rectal Anastomoses w/sup. & inf. rectal arteries Internal pudendal Runs with pudendal nerve Inferior rectal art. branches from this artery Posterior Division Exits greater sciatic foramen above piriformis In sciatic notch, can be injured in posterior column fractures or pelvic ring injuries Runs superiorly toward iliac fossa Supplies ilium, iliacus, & psoas muscles Run along sacrum, anterior to the sacral roots Supplies sacrum/sacral muscles/nerves Anastomoses w/median sacral art. (aorta) 244 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

ARTERIES • Pelvis 7 Deep circumflex iliac artery Deep dissection External iliac artery and vein Superficial circumflex artery Superficial epigastric artery Lateral femoral cutaneous nerve Deep artery of thigh Sartorius muscle (cut) Femoral artery and vein (cut) Pectineus muscle (cut) Iliopsoas muscle Superficial external pudendal artery Obturator canal Obturator externus muscle Adductor longus muscle (cut) Ascending, transverse and Anterior branch and descending branches of Posterior branch of Lateral circumflex obturator nerve femoral artery Medial circumflex Adductor brevis muscle femoral artery Iliac crest Gluteus medius m. (reflected) Posterior superior iliac spine Gluteus minimus m. Superior gluteal a. and n. Inferior gluteal a. and n. Piriformis m. Superior and Sacrospinous lig. inferior gemellus mm. Obturator internus m. Sacrotuberous lig. Gluteus maximus m. (reflected) Sciatic n. Posterior femoral cutaneous n. Trochanteric bursa Ischial tuberosity Quadratus femoris m. Medial femoral circumflex a. ARTERY COURSE COMMENT/SUPPLY EXTERNAL ILIAC ARTERY Supplies anterolateral abdominal wall muscles Deep circumflex iliac Runs laterally under internal oblique to Supplies anterior abdominal wall muscles iliac crest Terminal branch of external iliac artery Inferior epigastric Runs superiorly in transversalis fascia Supplies superficial abdominal tissues Supplies superficial abdominal tissues Femoral artery Continuation of EIA under inguinal ligament Supplies subcutaneous tissues in the pu- FEMORAL ARTERY bic region and the scrotum/labia majus Gives off circumflex (2) & perforating Superficial circumflex iliac In subcutaneous tissues toward ASIS branches Runs under quadratus femoris; can be in- Superficial epigastric In subcutaneous tissues toward umbilicus jured in posterior approach to hip Superficial & deep external Medially over the adductors & spermatic At risk in anterolateral approach to hip pudendal cord to inguinal and genital regions Profunda femoris (deep Between adductor longus & pectineus/ artery of thigh) adductor brevis Medial circumflex B/w pectineus & psoas, then posterior to femoral femoral neck under quadratus femoris Lateral circumflex femoral Runs laterally deep to sartorius & rectus NETTER’S CONCISE ORTHOPAEDIC ANATOMY 245

7 Pelvis • DISORDERS Osteitis pubis Contusion on iliac crest Inflamed bursa adjacent to ischial tuberosity Ischial tuberosity and hip pointer Sacroiliitis DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT • Inflammation or degenera- OSTEITIS PUBIS 1. Activity modification tion of pubic symphysis 2. Rest, NSAIDs Hx: Anterior pelvic pain, XR: AP pelvis (ϩ/Ϫ inlet & 3. Fusion if symptoms are • Etiology: repetitive micro- sports or trauma outlet views) trauma (sports) or fracture PE: Symphysis pubis is CT/MR: Not usually neces- refractory to conserva- tender to palpation sary for diagnosis tive care • Inflammation or degenera- tion of sacroiliac joint SACROILIITIS 1. Rest, NSAIDs 2. Injection can be diag- • Infection can also occur Hx: Low back pain XR/CT: SI joints, ϩ/Ϫ DJD here PE: SIJ tender to palpa- Bone Scan: r/o infection nostic & therapeutic tion, ϩ FABER test; in- LABS: CBC, ESR, CRP if in- (corticosteroid) • Assoc. w/Reiter’s syndrome jection can help diag- fection is suspected 3. Fusion: rarely indicated nosis • Inflammation of bursa of is- 1. Rest chial tuberosity ISCHIAL BURSITIS 2. NSAIDs 3. Activity modification: • Often from prolonged sitting Hx: Buttocks pain, sitting XR: Pelvis, r/o tuberosity • Aka “weaver’s bottom” PE: Ischial tuberosity avulsion decrease sitting or in- • Mimics hamstring injury tender to palpation; ac- MR: Can evaluate/ r/o crease cushion tive hamstrings NOT hamstring insertion injury • Direct trauma to iliac crest painful 1. Rest, NSAIDs • Common in contact sports 2. Padding to iliac crest ILIAC CREST CONTUSION (HIP POINTER) 3. Corticosteroid injection (e.g., football, hockey, etc) Hx: Trauma, “hip” pain XR: Pelvis, r/o fracture PE: Iliac crest tender to MR/CT: Usually not neces- palpation sary for diagnosis 246 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

SURGICAL APPROACHES • Pelvis 7 Iliacus (reflected) Window #1 Inguinal Window #3 ligament Window #1 Femoral nerve Fascia Iliopsoas (external Inguinal oblique) ligament Iliopsoas Spermatic Fascia Femoral nerve cord (external Window #2 oblique) External iliac artery and vein Spermatic cord Window #3 External iliac Window #2 External iliac artery and vein artery and vein Window #2 Window #1 Retropubic space of Iliopsoas Retzius Femoral nerve Window #3 Inguinal ligament Fascia (external Spermatic oblique) cord USES INTERNERVOUS PLANE DANGERS COMMENT • Open reduc- ILIOINGUINAL APPROACH • Good knowledge of abdominal tion, internal & pelvic anatomy essential to fixation of ac- 3 windows—interval (access): • Ext. iliac (EI) vessels perform this approach etabular frac- 1. Lateral to iliopsoas & femoral • Corona mortis (vessel tures involving • Must detach pelvic insertion anterior col- nerve (anterior, SIJ, iliac fossa, from obt. art. to EI art.) of abdominal muscles & ilia- umn of ace- pelvic brim) • Femoral nerve cus muscle for exposure tabulum 2. Between iliopsoas/femoral nerve • Lateral femoral cuta- & external iliac artery (pelvic • Use rubber drains around ilio- brim, lateral superior pubic neous nerve psoas/femoral n. & external il- ramus) • Inferior epigastric iac vessels to access windows 3. Medial to external iliac artery & spermatic cord (quadrilateral artery plate & retropubic space [of • Spermatic cord Retzius]) • Bladder (use a Foley) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 247

7 Pelvis • SURGICAL APPROACHES Quadratus femoris Joint capsule Gluteal sling (Gluteus maximus Gluteus medius insertion cut) (retracted) Gluteus maximus (split) Gluteal fascia Sciatic nerve Short external rotators Ilium (posterior column) Piriformis Ischium/ posterior wall of acetabulum USES INTERNERVOUS PLANE DANGERS COMMENT • Open reduction, KOCHER-LANGENBECK APPROACH • Heterotopic ossification internal fixation of is common, prophylaxis acetabular frac- No internervous plane • Sciatic nerve (e.g., XRT) is often needed. tures involving • Gluteus maximus (inf. gluteal n.) • Inferior gluteal artery posterior column • Superior gluteal • Do not take down quadra- of acetabulum fascia is split in line with its tus femoris due to vascular fibers; inferior gluteal nerve is vessels & nerve (esp. risk limit to the split. w/excessive retraction) • Tensor fasciae latae also split in line with its fibers 248 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Topographic Anatomy CHAPTER 8 Osteology Radiology Thigh/Hip Trauma Joints 250 Minor Procedures 251 History 253 Physical Exam 254 Origins and Insertions 258 Muscles 259 Nerves 260 Arteries 261 Disorders 265 Pediatric Disorders 266 Surgical Approaches 270 273 275 279 281

8 Thigh/Hip • TOPOGRAPHIC ANATOMY Anterior view Inguinal Iliac crest Posterior view ligament Iliac crest Gluteus Hip joint medius Anterior muscle superior iliac Sartorius spine muscle Tensor fasciae latae muscle Vastus Great Gluteus lateralis muscle saphenous maximus vein muscle Rectus femoris muscle Vastus Greater medialis trochanter Rectus femoris muscle of femur tendon (becoming part of quadriceps Semitendinosus Ischial femoris tendon) muscle tuberosity Iliotibial tract Adductor Gluteal magnus fold Patella muscle Iliotibial Patellar Gracilis tract ligament tendon Bicep femoris muscle Great Long head saphenous Short head vein Popliteal fossa STRUCTURE CLINICAL APPLICATION Iliac crest Site for “hip pointers”/contusion of lilac crest Common site for autologous bone graft harvest Greater trochanter Tenderness can indicate trochanteric bursitis. Ischial tuberosity Avulsion fracture (hamstrings) or bursitis can occur here. Iliotibial tract (band) Can snap over greater trochanter of femur, creating “snapping hip” syndrome. Tightness can cause lateral knee and/or thigh pain. Quadriceps muscle Atrophy can indicate an injury and/or contribute to knee pain. • Vastus lateralis • Vastus medialis Can rupture with eccentric loading. Defect is felt here. • Rectus femoris Popliteal artery pulse can be palpated here. • Vastus intermedius (not shown) Quadriceps tendon Popliteal fossa 250 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OSTEOLOGY • Thigh/Hip 8 Anterior view Posterior view Greater Head Piriformis fossa Greater trochanter Fovea for Head trochanter ligament of head Fovea for ligament Neck of head Lesser trochanter Neck Intertrochanteric crest Intertrochanteric line Calcar Lesser trochanter Pectineal line Gluteal tuberosity Linea aspera Medial lip Lateral lip Shaft (body) Line of attachment of border of Nutrient synovial membrane foramen Shaft (body) Line of reflection of synovial membrane Popliteal surface Line of attachment of fibrous capsule Line of reflection of fibrous capsule (unattached) Lateral epicondyle Adductor tubercle Medial epicondyle Lateral epicondyle Lateral condyle Patellar surface Medial condyle Lateral condyle Intercondylar fossa CHARACTERISTICS OSSIFY FUSE COMMENTS • Long bone characteristics FEMUR • Proximal femur Primary 7-8wk 16-18yr • Blood supply ‫ ؠ‬Head: nearly spherical (2⁄3) (Shaft) (fetal) ‫ ؠ‬Head/neck: primarily medial femoral cir- ‫ ؠ‬Neck: anteverted from shaft 19yr cumflex artery (also lateral FCA and of ‫ ؠ‬Greater trochanter: lateral Secondary 18yr ligamentum teres artery) ‫ ؠ‬Lesser trochanter: postero- Distal physis birth 16yr ‫ ؠ‬Shaft: nutrient artery (from profunda fem.) Head 1yr 16yr medial Gtr troch 4-5yr • Head vascularity is susceptible to disruption • Shaft: tubular, bows anteriorly Lsr troch 10yr in fracture or dislocation—leads to AVN ‫ ؠ‬Linea aspera posterior: inser- • Proximal femur bone density decreases with tion of fascia and muscles age, making it more susceptible to fracture • Distal femur: 2 condyles • Calcar femorale—vertically oriented dense ‫ ؠ‬Medial: larger, more posterior bone in posteromedial aspect of prox. femur ‫ ؠ‬Lateral: more anterior & proximal • Piriformis fossa—posteromedial base of gtr ‫ ؠ‬Trochlea: anterior articular trochanter: starting point for femoral nails depression between condyles • Neck/shaft angle: 120-135° • Femoral anteversion: 10-15° • Distal femur physis: grows approx. 7mm/yr NETTER’S CONCISE ORTHOPAEDIC ANATOMY 251

8 Thigh/Hip • OSTEOLOGY Bone Architecture in Relation to Physical Stress Wolff’s law. Bony structures orient themselves in form and mass to best resist extrinsic forces (ie, form and mass follow function) Principal Principal Femoral Calcar tensile compressive anatomic femorale group axis 3˚ Vertical Load 6˚ axis group Femoral Knee axis Greater mechanical trochanteric 87˚ group axis Tibial 81˚ 87˚ mechanical axis Secondary Ward’s tensile triangle Calcar group femorale Secondary Trabecular configuration compressive in proximal femur group Trabecular groups confirm to lines of stress in weight bearing GROUP COMMENT PROXIMAL FEMUR OSTEOLOGY • Proximal femur comprises several distinct trabecular bone groups that support the head and neck. • The presence or absence of these groups helps to determine the presence & degree of osteopenia in the prox. femur. • Malalignment of bone groups determines the fracture type in displaced femoral neck fractures. Primary compressive From superior femoral head to medial neck, strongest cancellous bone, supports body weight Primary tensile From inferior femoral head to lateral cortex Secondary compressive Oriented along lines of stress in proximal femur Secondary tensile Oriented along lines of stress in lateral proximal femur Greater trochanteric group Oriented along lines of stress within the greater trochanter Ward’s triangle Area of relative few trabeculae within the femoral neck Anatomic axis LOWER EXTREMITY ALIGNMENT Mechanical axis Definitions Knee axis Vertical axis Line drawn along the axis of the femur Lateral femoral angle Line drawn between center of femoral head and intercondylar notch Line drawn along the inferior aspect of both femoral condyles Knee axis Vertical line, perpendicular to the ground Mechanical axis Angle formed between the knee axis and the femoral axis Lateral femoral angle Relationships Parallel to the ground and perpendicular to vertical axis Average of 6° from anatomic axis Approximately 3° from the vertical axis 81° with respect to femoral anatomic axis 87° with respect to femoral mechanical axis 252 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

RADIOLOGY • Thigh/Hip 8 Acetabulum Acetabulum Fovea Greater trochanter Femoral head Femoral neck Femoral neck Greater trochanter Femoral head Lesser trochanter Lesser trochanter Greater trochanter Lesser trochanter Hip, AP xray Hip, Lateral xray Diaphysis Anterior bow of femur Diaphysis Metaphysis Metaphysis Femur, AP Femur, Lateral RADIOGRAPH TECHNIQUE FINDINGS CLINICAL APPLICATION Fractures, dislocations, arthritis AP pelvis Supine, beam at symphysis Both hips and pelvis Fractures, arthritis Fractures, arthritis AP hip Beam aimed at proximal femur Femoral head, acetabulum Often needed for preop fx films Lateral (frog Flex, abd. ER hip, beam at hip Fem. neck, head, acetab. rim Used intraop (fluoro) for ORIF leg) Fractures, tumors Lateral Flex contralateral hip to remove Femoral neck, head, acetabu- Fractures, tumors (cross-table) it; aim beam across table at lar rim. Ant & post. cortices Intraarticular acetabulum or neck fractures hip seen well on lateral Labral tears, AVN, stress fractures AP femur Supine, beam at mid femur Femur, soft tissues Stress fractures, infection, tumor Lateral femur Beam laterally at mid femur Femur, soft tissues See Chapter 7, Pelvis, for views of acetabulum. OTHER STUDIES CT Axial, coronal, & sagittal views Articular congruity, fracture fragments MRI Sequence protocols vary Labrum, cartilage, cancellous bone Bone scan Radioisotope All bones evaluated NETTER’S CONCISE ORTHOPAEDIC ANATOMY 253

8 Thigh/Hip • TRAUMA Posterior Dislocation Anteroposterior view. Anteroposterior radiograph Allis maneuver. Patient supine on table, under Dislocated femoral head lies posterior shows posterior dislocation anesthesia or sedation. Examiner applies firm and superior to acetabulum. Femur distal traction at flexed knee to pull head into adducted and internally rotated; hip acetabulum; slight rotary motion may also flexed. Sciatic nerve may be stretched help. Assistant fixes pelvis by pressing on anterior superior iliac spines Anterior Dislocation Anterior view. Femoral head in obturator Characteristic position foramen of pelvis; hip flexed and femur of affected limb. Hip widely abducted and externally rotated flexed, thigh abducted and externally rotated. DESCRIPTION EVALUATION CLASSIFICATION TREATMENT HIP DISLOCATION • High-energy trauma (esp. Hx: Trauma, severe pain, Posterior: Thompson: Early reduction essential MVA, dashboard injury) cannot move thigh/hip I: No or minor post. wall fx (Ͻ6 hr), then repeat or significant fall PE: Thigh position: II: Large posterior wall fx XR & neuro exam • Post.: adducted, flexed, IR III: Comminuted acetabular fx Posterior: • Orthopaedic emergency; • Ant.: abducted, flexed, ER IV: Acetabular floor fx I: Closed reduction and risk of femoral head AVN • Pain (esp. with motion), V: Femoral head fx abduction pillow increases with late/de- good neurovascular exam II-V: layed reduction (sciatic n.) Anterior: Epstein: 1. Closed reduction XR: AP pelvis, frog lateral I (A, B, C): Superior (open if irreducible) • Multiple associated inju- (femoral head appears of II (A, B, C): Inferior 2. ORIF( fracture or ex- ries ϩ/Ϫ fractures different size), femur and A: No associated fx cise fragment/LB) (e.g., femoral head/neck, knee series B: Femoral head fx Anterior: acetabulum) CT: R/o fx or bony fragments/ C: Acetabular fx Closed reduction, ORIF loose bodies (postreduction) if necessary • Posterior most common (85%) COMPLICATIONS: Posttraumatic osteonecrosis (AVN) (reduced risk with early reduction); sciatic nerve injury (posterior dislocations); femoral artery/nerve injury (anterior dislocations); osteoarthritis; heterotopic ossification 254 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Thigh/Hip 8 Type I. Impacted fracture Type II. Nondisplaced fracture Type III. Partially displaced Type IV. Displaced fracture. vertical fracture line generally suggests poorer prognosis DESCRIPTION EVALUATION CLASSIFICATION TREATMENT FEMORAL NECK FRACTURE • Mechanism Hx: Fall, pain, inability to Garden (4 types): Young (high-energy) ‫ ؠ‬Fall by elderly person most bear weight/walk I: Incomplete fracture; • Urgent reduction common PE: LE shortened, ab- valgus impaction ‫ ؠ‬High-energy injury in young ducted, externally rotated. II: Complete fracture; (CR vs OR) adults (e.g., MVA) Pain w/“rolling”/log roll nondisplaced • ORIF (3 parallel screws) extremity III: Complete fracture, • Intracapsular fractures XR: AP pelvis, cross-table partial displacement Elderly • Femoral head vascularity at lateral (varus) • Early medical evaluation MR: If symptomatic with IV: Complete fracture, • Types I & II: ORIF risk in displaced fractures negative XR (i.e., rule out total displacement • Associated with osteoporosis occult fracture) (3 screws) • High morbidity & complication • Types III & IV: hemiar- rates throplasty • Medically unstable, nonoperative COMPLICATIONS: Osteonecrosis (AVN): incidence increases with fx type (displacement) ϩ/Ϫ late segmental collapse; nonunion; hardware failure NETTER’S CONCISE ORTHOPAEDIC ANATOMY 255

8 Thigh/Hip • TRAUMA Intertrochanteric Fracture of Femur I. Nondisplaced fracture III. Comminuted displaced fracture Femoral Shaft Fractures O I II III IV Comminution Small cortical Butterfly 50% Large butterfly Severe discontinuity contact of cortex (zero rotational control) comminution DESCRIPTION EVALUATION CLASSIFICATION TREATMENT INTERTROCHANTERIC FRACTURE • Fall by an elderly per- Hx: Fall, pain, inability to Evans/Jensen: • Early medical evaluation son most common bear weight/walk • Type IA: Nondisplaced • Early (Ͻ48hr) ORIF PE: LE shortened, ER. • Type IB: 2 part displaced • Assoc. w/osteoporosis Pain w/“log rolling” of leg • Type IIA: 3 part, GT ‫ ؠ‬Sliding hip screw/plate • Occurs along or below XR: AP pelvis/hip cross-table ‫ ؠ‬Cephalomedullary nail MR: If symptomatic with fragment • Reverse obliquity intertrochanteric line negative XR (r/o occult • Type IIB: 3 part, LT ‫ ؠ‬Blade plate • Extracapsular fractures fracture) ‫ ؠ‬Cephalomedullary nail • Stable vascularity fragment • Nonoperative; medically • Most heal well with • Type III: 4 part Reverse obliquity unstable patient proper fixation COMPLICATIONS: Nonunion/malunion, decr. ambulatory status, hardware failure, mortality (20% in 1st 6 mo) FEMORAL SHAFT FRACTURE • Orthopaedic emergency Hx: Trauma, pain, swelling Winquist/Hansen (5 types): Operative: within 24hr • High-energy injury deformity, inability to walk/ Stable • Antegrade, reamed, bear weight 0: No comminution (e.g., MVA, fall) PE: Deformity, ϩ/Ϫ open I: Minimal comminution locked IM nail • Associated injuries wound & soft tissue injury; II: Comminuted: Ͼ50% of • Retrograde nail if check distal pulses (common) XR: AP/lateral femur; cortices intact needed • Potential source of Knee: trauma series Unstable • External fixation Hip: r/o ipsilateral femoral III: Comminuted: Ͻ50% of significant blood loss neck fx cortices intact ‫ ؠ‬Medically unstable • Compartment IV: Complete comminution, ‫ ؠ‬High-grade open fx no intact cortex Traction—if surgery de- syndrome can occur layed, medically unstable • Transport patient in patient traction COMPLICATIONS: Neurovascular injury/hemorrhagic shock, nonunion/malunion, hardware failure, knee injury (5%) 256 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Thigh/Hip 8 Distal Femur Fracture Transverse supra- Intercondylar (T or Y) Comminuted fracture Fracture of single condylar fracture fracture extending into shaft condyle (may occur in frontal or oblique plane) DESCRIPTION EVALUATION CLASSIFICATION TREATMENT SUBTROCHANTERIC FRACTURE • Within 5cm of lesser tro- Hx: Trauma, pain, inability Russell-Taylor: By type: chanter (LT) to bear weight Type I: no piriformis IA: standard IM nail PE: Shortened, rotated LE. fossa extension/in- IB: cephalomedullary nail • Mechanism: No ROM (pain), check volvement IIA: cephalomedullary nail with ‫ ؠ‬Low-energy fall: elderly, neurovascular status A: intact LT trochanteric start point pathologic fx XR: AP & lateral of femur. B: detached LT IIB: 95° blade plate or cephalo- ‫ ؠ‬High-energy: younger Also, AP pelvis, hip (AP Type II: fracture in- medullary nail with trochanteric (e.g., MVA) & cross-table lateral), volves piriformis start point & knee series fossa • Vascularity is tenuous, can CT: Usually not needed A: intact LT compromise healing B: detached LT • Rule out pathologic fx if fracture occurs with minimal/no trauma • High biomechanical stresses COMPLICATIONS: Nonunion, malunion, loss of fixation/implant failure, loss of some ambulatory function (esp. in elderly) DISTAL FEMUR FRACTURE • Mechanism: direct impact Hx: Trauma, pain, inability AO/Muller: • Nondisplaced/stable: ‫ ؠ‬Young: high energy to bear weight A: Extraarticular ‫ ؠ‬Cast, immobilizer, brace ‫ ؠ‬Elderly: low energy (fall) PE: Swollen, ϩ/Ϫ gross subtypes 1, 2, 3 deformity. Careful pulse B: Unicondylar • Displaced/unstable: • Articular congruity needed evaluation (Doppler subtypes 1, 2, 3 ‫ ؠ‬Extraarticular: plate or nail for normal knee function exam if needed) C. Bicondylar ‫ ؠ‬Intraarticular: anatomic re- XR: AP & lateral knee, fe- subtypes 1, 2, 3 duction of articular surface • Many associated injuries mur, tibia & locking plate/blade plate (e.g., tibia fx, knee ligament CT: Evaluate intraarticular injury) involvement & preop • External fixation: temporarily in plan open fx, severely swollen soft • Vascular injuries possible tissues, unstable patient • Quads/hamstrings: shorten fx. Gastroc: displace fx pos- teriorly COMPLICATIONS: Posttraumatic arthritis, nonunion/malunion, knee stiffness/loss of ROM NETTER’S CONCISE ORTHOPAEDIC ANATOMY 257

8 Thigh/Hip • JOINTS Anterior view Posterior view Anterior Iliofemoral ligament Iliofemoral ligament superior (Y ligament of Bigelow) iliac spine Ischiofemoral ligament Iliopectineal bursa Zona orbicularis Anterior inferior (over gap in ligaments) iliac spine Greater Pubofemoral Ischial trochanter Greater ligament spine trochanter Obturator crest Ischial tuberosity Superior pubic ramus Lesser Protrusion Intertrochanteric trochanter of synovial crest membrane Lesser trochanter Intertrochanteric line Anterior superior Acetabulum Femoral Labrum Femoral iliac spine head neck Joint opened: lateral view Anterior inferior iliac spine Lunate (articular) surface of Iliopubic eminence acetabulum Acetabular labrum Articular (fibrocartilaginous) cartilage Fat in acetabular Greater fossa (covered by trochanter synovial membrane) Head of femur Obturator artery Anterior branch Neck of femur Posterior branch Intertrochanteric Acetabular branch line Ligament of Ischial Obturator membrane head of femur (cut) Lesser tuberosity Transverse MRI, Hip: coronal trochanter acetabular ligament LIGAMENTS ATTACHMENTS COMMENTS HIP • The hip is a spheroidal (ball & socket) joint. It has intrinsic stability from osseous, ligamentous, & muscular structures. Labrum Along acetabular rim except inferiorly Deepens socket, increases femoral head coverage; can be torn (cause of hip pain) Transverse Anteroinferior to posteroinferior Covers cotyloid notch in inferior central acetabulum acetabular acetabulum Ligamentum teres Fovea (femoral head) to cotyloid notch Small artery to femoral head within this ligament Capsule Acetabulum to femoral neck Has some discrete thickenings (ligaments) ‫ ؠ‬Iliofemoral Superior: ASIS/ilium to greater trochanter Aka “Y ligament of Bigelow”; provides strong anterior (2 bands) Inferior: Ilium to intertrochanteric line/LT support, resists extension ‫ ؠ‬Pubofemoral Anterior pubic ramus to intertroch. line Prevents hyperextension of hip, inferior joint support ‫ ؠ‬Ischiofemoral Posterior acetabulum to superior femoral Broad, relatively weak ligament (minimal posterior neck support). Does not provide complete post. joint cov- erage, so lateral post. neck is extracapsular 258 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MINOR PROCEDURES • Thigh/Hip 8 Sites for injection/ aspiration of hip joint Site for injection/ aspiration of trochanteric bursa Trochanteric bursa STEPS HIP INJECTION/ASPIRATION 1. Ask patient about allergies 2. Place patient supine, palpate the greater trochanter 3. Prep skin over insertion site (iodine/antiseptic soap) 4. Anesthetize skin locally (quarter size spot) 5. Anterior: Find the point of intersection b/w a vertical line below ASIS and horizontal line from greater trochanter. Insert 20-gauge (3in) spinal needle upward/slightly medial direction at that point. Lateral: Insert a 20-gauge (3in) spinal needle superior and medial to greater trochanter until it hits the bone (the needle should be within the capsule, which extends down the femoral neck). Can “walk” needle up neck into joint. 6. Inject (or aspirate) local or local/steroid preparation into joint. (The fluid should flow easily if needle is in joint.) 7. Dress injection site TROCHANTERIC BURSA INJECTION 1. Ask patient about allergies 2. Place patient in lateral decubitus position, palpate the greater trochanter 3. Prep skin over lateral thigh (iodine/antiseptic soap) 4. Insert 20-gauge needle (at least 11⁄2 in; 3in in larger patients) into thigh to the bone at the point of most tenderness. Withdraw needle (1-2mm) so it is just off the bone and in the bursa. Aspirate to ensure needle is not in a vessel. 5. Inject local or local/corticosteroid preparation into bursa. May redirect needle slightly to inject a septated bursa 6. Dress injection site NETTER’S CONCISE ORTHOPAEDIC ANATOMY 259

8 Thigh/Hip • HISTORY Osteoarthritis Characteristic habitus and gait Trauma Mechanism of injury often by impact with dashboard, which drives femoral head backward, out of acetabulum LFCN entrapment Numbness and dysesthesias in lateral thigh QUESTION ANSWER CLINICAL APPLICATION 1. Age Young Trauma, developmental disorders 2. Pain Middle age–elderly Arthritis, fractures a. Onset b. Location Acute Trauma, (fracture, dislocation), infection Chronic Arthritis, labral tear c. Occurrence Lateral hip/thigh Bursitis, LFCN entrapment, snapping hip syndrome Buttocks/posterior thigh Consider spine etiology 3. Snapping Groin/medial thigh Hip joint or acetabular etiology (likely not from spine) 4. Assisted ambulation Anterior thigh Proximal femur pathology Ambulation/WB/motion Hip joint etiology (i.e., not pelvis/spine) At night Tumor, infection With ambulation Snapping hip syndrome, loose bodies, arthritis Cane/crutch/walker Use (and frequency) indicates severity of pain and condition 5. Activity tolerance Walk distance and activity cessation Less distance walked and fewer activities no longer 6. Trauma Fall, MVA performed ϭ more severe 7. Activity/work Repetitive use 8. Neurologic symptoms Pain, numbness, tingling Fracture, dislocation, labral tear 9. History of arthritides Multiple joints involved Femoral stress fracture LFCN entrapment, spine etiology (e.g., radiculopathy) Systemic inflammatory disease 260 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PHYSICAL EXAMINATION • Thigh/Hip 8 Femoral neck fracture Posterior hip dislocation Typical deformity injured limb adducted, internally rotated and flexed at hip and knee, with knee resting on opposite thigh Typical deformity of injured limb in shortened, externally rotated position Anterior hip dislocation Characteristic position of affected limb. Hip flexed, thigh abducted and externally rotated. Flexion contracture of hip joint EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION Skin Discoloration, wounds INSPECTION Position Gross deformity Shortened, ER Trauma Gait Adducted, IR Fracture, dislocation Antalgic (painful) Abducted, ER Lurch (Trendelenburg) Flexed Femoral neck fracture; intertrochanteric fracture Lurch Posterior dislocation Anterior dislocation Bony structures Hip flexion contracture Decreased stance phase Knee, ankle, heel (spur), midfoot, toe pain Lean laterally (on WB side) Gluteus medius weakness Lean posteriorly (keep hip ext) Gluteus maximus weakness PALPATION Greater trochanter/bursa Pain/palpable bursa: infection/bursitis, gluteus Lesser trochanter medius tendinitis Snapping—IT band may snap over GT Snapping— Psoas tendon may snap over LT NETTER’S CONCISE ORTHOPAEDIC ANATOMY 261

8 Thigh/Hip • PHYSICAL EXAMINATION Flexion Internal External rotation rotation Hip flexion-rotation exercises with patient supine. Hip and knee passively flexed, then limb rotated laterally and medially as pain permits Internal rotation 120° 90˚ Limitation of internal rotation of left Flexion hip. Hip rotation best assessed with patient in prone position because Extension any restriction can be detected and measured easily 0˚ EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION RANGE OF MOTION Flexion Supine: knee to chest Normal: 120-135° Thomas test Rule out flexion contracture (see Special Tests, p. 263) Extension Prone: lift leg off table Normal: 20-30° Abduction/adduction Supine: leg lateral/medial Normal: Abd: 40-50°, Add: 20-30° Internal/external rotation Seated: foot lateral/medial Normal: IR: 30°, ER: 50° Prone: flex knee leg in/out Normal: IR: 30°, ER: 50° NEUROVASCULAR Sensory Genitofemoral nerve (L1-2) Proximal anteromedial thigh Deficit indicates corresponding nerve/root lesion Obturator nerve (L2-4) Inferomedial thigh Deficit indicates corresponding nerve/root lesion Lat. femoral cutaneous n. (L2-3) Lateral thigh Deficit indicates corresponding nerve/root lesion Femoral nerve Anteromedial thigh Deficit indicates corresponding nerve/root lesion Post. femoral cutaneous n. (S1-3) Posterior thigh Deficit indicates corresponding nerve/root lesion Motor Obturator nerve (L2-4) Thigh/hip adduction Weakness ϭ adductor muscle group or nerve/root lesion Superior gluteal nerve L5) Thigh abduction Weakness ϭ gluteus medius or nerve/root lesion Femoral nerve (L2-4) Hip flexion Weakness ϭ iliopsoas or nerve/root lesion Knee extension Weakness ϭ quadriceps or nerve/root lesion Inferior gluteal nerve (L5-S2) Hip extension Weakness ϭ gluteus maximus or nerve/root lesion Sciatic: Knee flexion Weakness ϭ biceps long head or nerve/root lesion Tibial portion (L4-S3) Knee flexion Weakness ϭ biceps short head or nerve/root lesion Peroneal portion (L4-S2) Other Reflex None Pulses Femoral 262 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PHYSICAL EXAMINATION • Thigh/Hip 8 Stinchfield test. Pain with resisted straight leg raise indicates hip joint pathology. Inpingement test. Log roll test. Pain with hip flexion, adduction, Examiner places hands and internal rotation indicative of on limb, gently rolls hip femoroacetabular impingement into internal and external rotation. and for early arthritis. 15˚ Thomas’ sign Hip flexion contracture determined with patient supine. Unaffected hip flexed only until lumbar spine is flat against examining table. Affected hip cannot be fully extended, and angle of flexion is recorded. EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION SPECIAL TESTS Impingement Supine: flex, adduct, IR hip Pain may be indicative of femoral acetabular impingement. FABER/Patrick Flex, ABduct, ER hip, then Positive if painful. SI joint or hip pathology. abduct more (figure of 4) Log roll Supine, hip extended: IR/ER Pain in hip is consistent with arthritis. Stinchfield Resisted straight leg raise Pain is positive test for hip pathology. Thomas sign Supine; one knee to chest If opposite thigh elevates off table, flexion contracture. Ober On side: flex and abduct hip Extend and adduct hip; if stays in abduction, ITB contracture. Piriformis On side: adduct hip Pain in hip/pelvis indicates tight piriformis (compressing sciatic nerve). 90-90 straight leg Flex hip & knee 90°, extend Ͼ20° of flexion after full knee extension ϭ tight hamstrings. knee Ely’s Prone: passively flex knee If hip flexes as knee is flexed, tight rectus femoris muscle. Leg length ASIS to medial malleolus A measured difference of Ͼ1cm is positive. Meralgia Pressure medial to ASIS Reproduction to pain, burning, numbness ϭ LFCN entrapment. See Chapter 7, Pelvis, for Trendelenburg test. NETTER’S CONCISE ORTHOPAEDIC ANATOMY 263

8 Thigh/Hip • PHYSICAL EXAMINATION Ortolani’s (reduction) test “clunk” With baby relaxed and content on firm surface, hips and knees flexed to 90°. Hips examined one at a time. Examiner grasps baby’s thigh with middle finger over greater trochanter and lifts thigh to bring femoral head from its dislocated posterior position to opposite the acetabulum. Simultaneously, thigh gently abducted, reducing femoral head into acetabulum. In positive finding, examiner senses reduction by palpable, nearly audible “clunk” Allis’ or Galeazzi’s sign With knees and hips flexed, knee on affected side lower because femoral head lies posterior to acetabulum in this position Barlow’s (dislocation) test Test for limitation of Reverse of Ortolani’s test. If femoral head is in abduction. Patient acetabulum at time of examination, Barlow’s test supine and relaxed on is performed to discover any hip instability. Baby’s thigh table. Legs gently and grasped as above and adducted with gentle downward passively abducted to pressure. Dislocation is palpable as femoral head determine range of slips out of acetabulum. Diagnosis confirmed motion of each. with Ortolani’s test Seen in Perthes disease. EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION SPECIAL TESTS Ortolani (peds) Hips at 90°, abduct hips A clunk indicates the hip(s) was dislocated and now reduced Barlow (peds) Hips at 90°, posterior A clunk indicates the hip(s) is now dislocated, should reduce with force Ortolani Galeazzi (peds) Supine: flex hips & knees Any discrepancy in knee height: 1. Dislocated hip, 2. Short femur 264 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

ORIGINS AND INSERTIONS • Thigh/Hip 8 Sartorius muscle Biceps femoris (long head) Rectus femoris muscle and semitendinosus muscles Obturator externus muscle (in piriformis Pectineus muscle fossa) Gluteus medius turator externus muscle Piriformis muscle Obturator muscle internus Quadratus femoris Sartorius muscle Adductor muscle Rectus femoris magnus muscle Iliopsoas muscle muscle bturator internus Semimembranosus Gluteus maximus d superior and muscle muscle erior gemellus Quadratus uscles femoris Vastus lateralis muscle Piriformis Adductor Pectineus muscle Adductor magnus muscle longus muscle luteus minimus muscle Vastus Adductor brevis uscle medialis muscle Adductor muscle Vastus Vastus lateralis intermedius muscle muscle brevis muscle Adductor longus Biceps femoris muscle opsoas muscle Quadratus Gracilis muscle muscle (short head) Vastus medialis femoris Adductor magnus Adductor muscle muscle muscle magnus muscle Vastus intermedius Adductor magnus muscle Vastus muscle lateralis muscle Gastrocnemius muscle (medial head) Plantaris muscle Gastrocnemius muscle (lateral head) Popliteus muscle Origins Insertions Semimembranosus muscle Popliteus muscle Articularis genus Adductor Note: Width of zone of attachments to posterior muscle magnus aspect of femur (linea aspera) is greatly exaggerated muscle Iliotibial tract Biceps femoris Sartorius muscle Pes anserinus muscle Gracilis muscle Semitendinosus muscle uadriceps femoris uscle (rectus moris, vastus lateralis, stus intermedius and stus medialis via tellar ligament) PUBIC RAMI (ASPECT) GREATER TROCHANTER ISCHIAL TUBEROSITY LINEA ASPERA/ POSTERIOR FEMUR Pectineus (pectineal line/sup) Piriformis (anterior) Inferior gemellus Adductor magnus (inferior) Obturator internus (anterior) Quadratus femoris Adductor magnus* Adductor longus (anterior) Superior gemellus Semimembranosus Adductor longus Adductor brevis (inferior) Gluteus medius (posterior) Semitendinosus Adductor brevis Gracilis (inferior) Gluteus minimus (anterior) Biceps femoris (LH) Biceps femoris (SH) Psoas minor (superior) Adductor magnus* Pectineus Gluteus maximus Vastus lateralis Vastus medialis *Adductor magnus has two origins. NETTER’S CONCISE ORTHOPAEDIC ANATOMY 265

8 Thigh/Hip • MUSCLES Superficial dissections Lateral cutaneous nerve of thigh (cut) Sartorius muscle (cut) Anterior superior iliac spine Iliopsoas muscle Femoral nerve, Inguinal ligament Tensor fasciae latae artery and vein muscle (retracted) Pectineus muscle Iliopsoas muscle Deep artery Superficial circumflex Gluteus of thigh iliac vessels minimus and medius Adductor longus muscle Superficial muscles epigastric vessels Lateral circumflex Superficial and femoral Deep external artery pudendal vessels Femoral sheath Rectus Adductor canal femoris (opened by re- Femoral nerve, muscle moval of sartorius artery and vein muscle) Vastus Pectineus lateralis Saphenous nerve muscle muscle Nerve to vastus Deep artery Vastus medialis muscle of thigh medialis muscle Adductor Gracilis magnus muscle muscle Saphenous nerve and saphenous Anteromedial Adductor branch of descending intermuscular longus genicular artery septum covers muscle entrance of femoral vessels to Sartorius popliteal fossa muscle (adductor hiatus) Vastus medialis muscle Sartorius muscle (cut) Fascia lata (cut) Rectus femoris muscle Infrapatellar branch Vastus lateralis muscle of saphenous nerve Tensor fasciae latae muscle MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT Articularis Distal anterior ANTERIOR Pulls capsule supe- May join with vastus genus femoral shaft riorly in extension intermedialis Sartorius ASIS Synovial capsule Femoral Flex, ER hip Can avulse from ASIS (avulsion fracture) Rectus femoris 1. AIIS Prox. med. tibia Femoral Flex thigh, extend 2. Sup. acetab. rim (pes anserinus) leg Can avulse from AIIS Vastus lateralis Gtr. trochanter, lat. (avulsion fracture) linea aspera Quadriceps Extend leg Oblique fibers can Vastus inter- Proximal femoral affect Q angle medius shaft Patella/tibial Femoral Extend leg Covers articularis Vastus medialis Intertrochant. line, tubercle genu med. linea aspera Extend leg Weak in many patello- Lateral patella/ Femoral femoral disorders tibia tubercle Patella/tibia Femoral tubercle Medial patella/ Femoral tibia tubercle 266 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MUSCLES • Thigh/Hip 8 Deep circumflex iliac artery Deep dissection Lateral cutaneous nerve of thigh External iliac artery and vein Sartorius muscle (cut) Inguinal ligament (Poupart) Iliopsoas muscle Femoral artery and vein (cut) Pectineus muscle (cut) Tensor fasciae latae Obturator canal muscle (retracted) Obturator externus muscle Gluteus medius and Adductor longus muscle (cut) minimus muscles Anterior branch and Posterior branch of obturator nerve Femoral nerve Rectus femoris muscle (cut) Quadratus femoris muscle Ascending, transverse and Adductor brevis muscle descending branches of Lateral circumflex femoral artery Adductor magnus muscle Gracilis muscle Medial circumflex femoral artery Cutaneous branch of obturator nerve Pectineus muscle (cut) Femoral artery and vein (cut) Deep artery of thigh Articular branch Perforating branches Saphenous branch Adductor hiatus Adductor longus muscle (cut) Sartorius muscle (cut) Vastus lateralis muscle Adductor magnus tendon Vastus intermedius muscle Adductor tubercle on medial epicondyle of femur Rectus femoris muscle (cut) Infrapatellar branch of Saphenous nerve Saphenous nerve Vastus medialis muscle Quadriceps femoris tendon Medial patellar retinaculum Patellar ligament MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT Obturator Ischiopubic rami, MEDIAL externus obturator memb Piriformis fossa Obturator ER thigh Insertion at start Adductor Body of pubis point of IM nail longus (inferior) Adductor Body and inferior Hip Adductors brevis pubic ramus Adductor 1. Pubic ramus Linea aspera Obturator Adducts thigh Tendon can ossify magnus 2. Ischial tub. (mid 1⁄3) Gracilis Body and inferior pubic ramus Pectineal line, Obturator Adducts thigh Deep to pectineus Pectineus linea aspera Pectineal line of pubis Linea aspera, 1. Obturator Adducts & flex/ Muscle has two add. tubercle 2. Sciatic extend thigh separate parts Prox. med. tibia Obturator Adduct thigh, Used in ligament (pes anserinus) flex/IR leg reconstruction Hip Flexors Pectineal line of Femoral Flex and adducts Part of femoral tri- femur thigh angle floor NETTER’S CONCISE ORTHOPAEDIC ANATOMY 267

8 Thigh/Hip • MUSCLES Iliac crest Deep dissection Gluteal aponeurosis and gluteus medius muscle (cut) Superior cluneal nerves Gluteus maximus muscle (cut) Superior gluteal artery and nerve Medial cluneal nerves Gluteus minimus muscle Inferior gluteal artery and nerve Tensor fasciae latae muscle Pudendal nerve Nerve to obturator internus Piriformis muscle (and superior gemellus) Gluteus medius muscle (cut) Posterior cutaneous nerve of thigh Superior gemellus muscle Sacrotuberous ligament Greater trochanter of femur Ischial tuberosity Inferior cluneal nerves (cut) Obturator internus muscle Adductor magnus muscle Inferior gemellus muscle Gracilis muscle Sciatic nerve Gluteus maximus muscle (cut) Muscular branches of sciatic nerve Quadratus femoris muscle Semitendinosus muscle (retracted) Semimembranosus muscle Medial circumflex femoral artery Sciatic nerve Articular branch Vastus lateralis muscle Adductor hiatus and iliotibial tract Popliteal vein and artery Superior medial genicular artery Adductor minimus part of Medial epicondyle of femur adductor magnus muscle Tibial nerve 1st perforating artery (from Gastrocnemius muscle (medial head) deep artery of thigh) Medial sural cutaneous nerve Adductor magnus muscle Small saphenous vein 2nd and 3rd perforating arteries (from deep artery of thigh) 4th perforating artery (termination of deep artery of thigh) Long head (retracted) Biceps femoris Short head muscle Superior lateral genicular artery Common fibular (peroneal) nerve Plantaris muscle Gastrocnemius muscle (lateral head) Lateral sural cutaneous nerve MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT Semitendinosus Ischial tuberosity POSTERIOR: HAMSTRINGS Extend thigh, flex Tendon used in lig- leg ament reconstruc- Semimembranosus Ischial tuberosity Proximal medial Sciatic tions (ACL) Ischial tuberosity tibia (pes anse- (tibial) Extend thigh, flex Biceps femoris: Linea aspera, rinus) leg A border in medial long head supracondylar Extend thigh, flex approach Biceps femoris: line Posterior medial Sciatic leg short head Can avulse front or- tibial condyle (tibial) Extend thigh, flex igin (avulsion fx) leg Head of fibula Sciatic Shares tendon in- (tibial) sertion with long head Fibula, lateral Sciatic tibia (peroneal) 268 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MUSCLES • Thigh/Hip 8 Sartorius muscle Fascia lata Branches of femoral nerve Deep artery and vein of thigh Femoral artery and vein Adductor longus muscle Pectineus muscle Great saphenous vein Iliopsoas muscle Rectus femoris muscle Obturator nerve (anterior branch) Adductor brevis muscle Vastus medialis muscle Obturator nerve (posterior branch) Lateral cutaneous nerve of thigh Gracilis muscle Vastus intermedius muscle Adductor magnus muscle Femur Sciatic nerve Vastus lateralis muscle Posterior cutaneous nerve of thigh Tensor fasciae latae muscle Semimembranosus muscle Iliotibial tract Semitendinosus muscle Gluteus maximus muscle Biceps femoris muscle (long head) Vastus medialis muscle Medial intermuscular septum of thigh Rectus femoris muscle Vastus intermedius muscle Vastus lateralis muscle Sartorius muscle Iliotibial tract Nerve to vastus medialis muscle Saphenous nerve Lateral intermuscular Femoral artery and vein in adductor septum of thigh canal Biceps femoris Short head Great saphenous vein Adductor longus muscle muscle Long head Semitendinosus muscle Gracilis muscle Semimembranosus muscle Adductor brevis muscle Deep artery and vein of thigh Rectus femoris tendon Adductor magnus muscle Vastus intermedius muscle Posterior intermuscular septum of thigh Iliotibial tract Sciatic nerve Vastus medialis muscle Vastus lateralis muscle Sartorius muscle Articularis genus muscle Saphenous nerve and descending genicular artery Great saphenous vein Lateral intermuscular Gracilis muscle septum of thigh Adductor magnus tendon Femur Popliteal vein and artery Biceps femoris muscle Semimembranosus muscle Common fibular (peroneal) nerve Tibial nerve Semitendinosus muscle STRUCTURE RELATIONSHIP COMPARTMENTS Anterior Quadriceps: vastus lateralis, vastus intermedius, vastus medius, rectus femoris Posterior Biceps femoris (long head and short head), semitendinosus, semimembranosus, sciatic nerve Medial Adductor magnus, adductor longus, adductor brevis, gracilis, femoral artery and vein FASCIOTOMIES Lateral incision Release the anterior compartment and posterior compartment Medial incision Release the medial compartment NETTER’S CONCISE ORTHOPAEDIC ANATOMY 269

8 Thigh/Hip • NERVES Obturator nerve Obturator externus muscle (L2, 3, 4) Posterior branch Adductor brevis muscle Articular branch Adductor longus muscle (cut) Anterior branch Adductor magnus muscle Posterior branch (ischiocondylar, or Cutaneous branch “hamstrings,” part supplied by sciatic [tibial] nerve) Articular branch Gracilis muscle to knee joint Cutaneous Adductor hiatus innervation Note: Only muscles innervated by obturator nerve shown LUMBAR PLEXUS Anterior Division Obturator (L2-4): exits via obturator canal, splits into anterior and posterior divisions. Can be injured by retractors placed behind the transverse acetabular ligament. Sensory: Inferomedial thigh: via cutaneous branch of obturator nerve Motor: Gracilis (anterior division) Adductor longus (anterior division) Adductor brevis (anterior/posterior divisions) Adductor magnus (posterior division) 270 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

NERVES • Thigh/Hip 8 Genitofemoral nerve T12 Femoral branch Lateral cutaneous of genitofemoral nerve of thigh (L2, 3) L1 Femoral nerve (L2, 3, 4) L2 Lumbar plexus L3 Obturator nerve L4 Iliacus muscle Lumbosacral Psoas major muscle (lower part) trunk Lateral cutaneous Articular branch nerve of thigh Sartorius muscle Anterior cutaneous (cut and reflected) branches of femoral nerve Pectineus muscle Quadriceps Rectus Sartorius Psoas major muscle femoris femoris muscle muscle muscle (cut and Genitofemoral nerve (cut and reflected) reflected) Lateral cutaneous Saphenous nerve of thigh Vastus nerve Femoral nerve intermedius muscle Genital branch and Femoral branch of Vastus genitofemoral nerve medialis muscle Obturator nerve Vastus lateralis muscle Articularis genus muscle LUMBAR PLEXUS Genitofemoral (L1-2): pierces psoas, lies on anteromedial surface of psoas and divides into two branches Sensory: Femoral branch: proximal anterior thigh (over femoral triangle) Genital branch: scrotum/labia Motor: None (in thigh) Posterior Division Lateral femoral cutaneous (LFCN) (L2-3): crosses inferior to ASIS (can be compressed at or near ASIS) Sensory: Lateral thigh Motor: None Femoral (L2-4): lies b/w psoas major & iliacus; branches in femoral triangle. Saphenous nerve runs under sartorius. Sensory: Anteromedial thigh—via anterior/intermediate cutaneous nerves Motor: Psoas Pectineus Sartorius • Quadriceps ‫ ؠ‬Rectus femoris ‫ ؠ‬Vastus lateralis ‫ ؠ‬Vastus intermedialis ‫ ؠ‬Vastus medialis NETTER’S CONCISE ORTHOPAEDIC ANATOMY 271

8 Thigh/Hip • NERVES Greater sciatic foramen Sciatic nerve (L4, 5, S1, 2, 3) Posterior cutaneous nerve of thigh Common fibular (peroneal) (S1, 2, 3) division of sciatic nerve Inferior cluneal Short head of Cutaneous innervation nerves biceps femoris muscle Perineal branches Long head (cut) Tibial division of biceps femoris of sciatic nerve muscle Long head (cut) of Common fibular Posterior biceps femoris muscle (peroneal) nerve cutaneous nerve Adductor magnus muscle of thigh (also partially supplied Articular by obturator nerve) branch Semitendinosus muscle Semimembranosus muscle Tibial nerve Articular branch SACRAL PLEXUS Sciatic nerve: a single nerve with 2 distinct parts; it divides in the distal thigh into tibial & common peroneal nerves Anterior Division Tibial (L4-S3): descends (as sciatic) in posterior thigh deep to hamstrings and superficial to adductor magnus muscle Sensory: None (in thigh) Motor: Biceps femoris (long head) Semitendinosus Semimembranosus Posterior Division Common peroneal (L4-S2): descends (as sciatic) in posterior thigh deep to hamstrings and superficial to adductor magnus Sensory: None (in thigh) Motor: Biceps femoris (short head) Posterior femoral cutaneous nerve (PFCN) (S1-3): through greater sciatic foramen, medial to sciatic nerve Sensory: Posterior thigh Motor: None 272 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Deep circumflex iliac artery ARTERIES • Thigh/Hip 8 Superficial External iliac artery circumflex iliac artery Inferior epigastric artery Superficial epigastric artery Femoral artery Superficial external pudendal artery Obturator artery Ascending branch, Deep external pudendal artery Transverse branch, Medial circumflex femoral artery Descending branch of Femoral artery Lateral circumflex femoral artery Muscular branches Deep artery of thigh Descending genicular artery (profunda femoris) Articular branch Saphenous branch Perforating branches Femoral artery passing through adductor hiatus ARTERY BRANCHES COMMENT Obturator Anterior/posterior branches Runs through obturator foramen FEMORAL ARTERY In femoral triangle, runs in adductor canal (under sartorius, b/w vastus medialis & adductor longus), then passes poste- rior through the adductor hiatus and becomes the popliteal artery posterior to the distal femur and knee. Femoral artery Superficial circumflex iliac Supplies superficial abdominal tissues (superficial fem. [(SFA]) Superficial epigastric Supplies superficial abdominal tissues Superficial and deep Supplies subcutaneous tissues in pubic region external pudendal and scrotum/labia majus Profunda femoris (deep artery) Primary blood supply to thigh. See below Descending genicular artery Anastomosis at knee to supply knee Articular branch Saphenous branch Profunda femoris (deep Medial femoral circumflex Supplies femoral neck, under quad. femoris artery of thigh) Lateral femoral circumflex Supplies femoral neck Ascending branch Forms anastomosis at femoral neck Transverse branch To greater trochanter Descending branch At risk in anteromedial approach to hip Perforators/muscular branch Supplies femoral shaft and thigh muscles NETTER’S CONCISE ORTHOPAEDIC ANATOMY 273

8 Thigh/Hip • ARTERIES Anterior view Posterior view Subsynovial intracapsular Acetabular Subsynovial intracapsular arterial ring branch of arterial ring obturator artery Retinacular Superior (often minute) Superior Retinacular Posterior arteries arteries Anterior Inferior (subsynovial) (subsynovial) Inferior Anastomosis be- lliopsoas Medial Anastomosis tween medial and tendon circumflex lateral circumflex femoral Ischiofemoral femoral arteries Medial circumflex artery ligament and femoral artery joint capsule Extracapsular ring Deep artery Lateral Extracapsular lliofemoral (Y) ligament of thigh circumflex ring and joint capsule femoral artery Nutrient artery Nutrient artery Ascending, of femur of femur Transverse, Descending branches of Lateral circumflex femoral artery ARTERY COURSE COMMENT/SUPPLY ARTERIES OF THE FEMORAL NECK Profunda Femoris Medial femoral circumflex Between pectineus and psoas, Main blood supply to adult femoral head (MFCA) then posterior to femoral neck Major contributor to extracapsular ring/anastomosis under quadratus femoris Lateral femoral circumflex Deep to sartorius & rectus fem. Less significant blood supply in adult femoral head Ascending branch Ascends anterior femoral neck Major contributor to extracapsular ring/anastomosis Transverse branch Across proximal femur to GT Gives partial supply to greater trochanter (GT) Descending branch Under rectus femoris At risk in anterolateral approach to hip 1st Perforator Ascending branch Can contribute to extracapsular ring/anastomosis Extracapsular ring—formed at the base of the femoral neck primarily from branches of MFCA and LFCA Lateral branches From ring, laterally toward GT Supply greater trochanter Ascending cervical arteries Along extracapsular femoral neck Branch from the extracapsular ring Intracapsular continuation of cervical arteries Retinacular arteries Along intracapsular femoral neck Form a second intracapsular ring at base of head Subsynovial intracapsular arterial ring—formed at the base of the femoral head Epiphyseal arteries Enter bone at border of articular Will form intraosseous anastomoses Lateral epiphyseal art. surface In posterosuperior neck Lat. epiphyseal supplies most of WB femoral head Obturator Artery Artery of ligamentum teres Thru ligamentum teres to fovea Minimal supply to the adult femoral head Medial epiphyseal art. Interosseous terminal branches Anastomose with lateral epiphyseal arteries Other Arteries Superior & inferior gluteal Can contribute to extracapsular ring/anastomosis Pediatric femoral head blood supply: 0-4yr MFCA, LFCA, and ligamentum teres artery; 4-8yr: mostly MFCA, minimal LFCA and ligamentum teres artery; Ͼ8yrs: MFCA is predominant 274 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Lateral femoral DISORDERS • Thigh/Hip 8 cutaneous nerve Arrows show the presence Entrapment of nerve of buttressing and sclerosis under inguinal ligament in the femoral neck Coronal MRI reveals bilateral fatigue fractures (arrows) in the femoral neck Reprinted with permission from Resnick D. Kransdorf M. Bone and Joint Imaging, 3rd edition, Elesevier, Philadelphia, 2005. DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT • Subtle abnormal hip FEMOROACETABULAR IMPINGEMENT 1. NSAIDs, activity modifi- morphology causes bony cation abutment. 2 types Hx: Insidious onset, groin XR: AP/lateral of hip ‫ ؠ‬Cam: femoral non- pain, worse with activity Cam: femoral neck 2. Surgical dislocation and sphericity PE: Decreased ROM (esp. “bump,” ϩ/Ϫ herniation neck and/or acetabular ‫ ؠ‬Pincer: acetabulum IR),ϩ impingement test pit, decreased offset reshaping overcoverage (flex, add, IR hip) Pincer: increased acetabu- lar coverage 3. Osteotomy in selected • Causes early DJD MR: Labral tear, chondral cases injury • Excessive loading of hip 4. THA if advanced DJD • 2 types: tension (superior FEMORAL NECK STRESS (FATIGUE) FRACTURE • Compression: limited neck), compression Hx: Increased activity with XR: AP, AP in IR, lateral weight-bearing (inferior neck) new onset of hip/groin MR: Best study for early • Common in military pain detection of fracture • Tension: urgent percuta- recruits PE: ϩ/Ϫ pain with and/or BS: Shows fx subacutely neous pinning (prevent diminished ROM displacement) • Nerve trapped near ASIS • Due to activity (hip ex- MERALGIA PARESTHETICA 1. Remove compressive entity (e.g., belt, tight tension), clothing (e.g., Hx: Pain/burning in lateral XR: AP/lateral of hip: rule clothing, etc.) belt), or repetitive com- thigh out other pathology pression PE: Decr. sensation on lat- 2. Surgical release: rare eral thigh, ϩ meralgia Snapping in hip. 3 types External/Internal: 1. External: ITB over GT SNAPPING HIP (COXA SALTANS) 1. Activity modification, PT 2. Internal: psoas over 2. Consider injection Hx: Snapping at hip XR: AP/lateral hip: rule out 3. Surgical release: very femoral head or iliopec- ϩ/Ϫ pain osseous abnormality tineal eminence (e.g., spur) and hip DJD rare 3. Intraarticular: usually PE: Palpate the tendon (ITB MR: Loose body, labral tear Intraarticular: LB removal loose body or psoas tendon) then flex US/bursography: Psoas & extend hip, feeling for tendon 1. NSAIDs, PT (ITB • Inflammation of bursa snap. (external over GT; stretching) over greater trochanter internal over LT) 2. Steroid injection • FϾM, middle age TROCHANTERIC BURSITIS 3. Surgical excision—rare Hx: Lateral hip pain, cannot XR: AP pelvis, AP/lateral of sleep on affected side hip: rule out spur, OA, PE: Point tender at tro- calcified tendons chanter, pain w/adduction NETTER’S CONCISE ORTHOPAEDIC ANATOMY 275

8 Thigh/Hip • DISORDERS Osteoarthritis Advanced degenerative changes in acetabulum Erosion of cartilage and deformity of femoral head Radiograph of hip shows typical degeneration of cartilage and secondary bone changes with spurs at margins of acetabulum DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT • Loss or damage to ar- OSTEOARTHRITIS 1. NSAIDs/PT ticular cartilage 2. Injection/activity modi- Hx: Chronic hip or groin XR: AP pelvic/AP/lateral hip • Etiology: Primary— pain, increasing over 1. Joint space narrowing fication, cane (in idiopathic; Secondary— time & with activity 2. Osteophytes opposite hand) posttraumatic, infection, PE: Decreased ROM (first 3. Subchondral sclerosis 3. Osteotomy (young) pediatric hip disease IR), ϩ log roll, ϩ/Ϫ flex 4. Bony cysts 4. Arthrodesis (young) contracture/antalgic gait 5. Total hip arthroplasty OSTEONECROSIS (AVASCULAR NECROSIS/AVN) Stage: 0-1: Limited WB, obser- • Necrosis of femoral Hx: Groin pain worse Classification: Modified Ficat vation head due to vascular with activity 0: Asymptomatic, nl XR, ϩ MR 2: Core decompression disruption PE: Limited ROM (esp IR 1: Symptomatic, nl XR, ϩ MR 3: Consider vascularized & abd), antalgic gait 2: XR: sclerosis, no collapse fibula or femoral oste- • Assoc. w/trauma, ste- XR: AP/lateral: stage- 3: XR: ϩ collapse (crescent otomy roid or EtOH use, in- specific findings (see 4-6: Total hip arthro- flammatory disorders. classification) sign) plasty—appropriate for MRI: Most sensitive study, 4: Flat femoral head, nl ace- most patients. Hip fu- • MϾF, 30-40’s, 50% shows early changes in sion: in young laborers bilateral femoral head tabulum BS: Replaced by MRI 5: Joint narrowing, early DJD • Greater femoral head 6: Advanced DJD incl. acetab- involvement, associated ulum w/poor prognosis 276 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

DISORDERS • Thigh/Hip 8 35° to 45° Reamers of increasing size used to enlarge acetabulum to fit Reamer of appropriate size inserted acetabular cup of Final position of cup 35° to 45° lateral and acetabulum reamed to receive acetabular component preselected size inclination and 15° anteversion TOTAL HIP ARTHROPLASTY General Information • Goals: alleviate pain, maintain personal independence, allow performance of activities of daily living (ADLs). • Common procedure with high satisfaction rates for primary procedure; revisions are also becoming more common. • Advances in techniques and materials are improving implant survival; this procedure available to younger pts. Materials • Cups (acetabulum) and stems (femur). Usually made of titanium. Stainless steel or cobalt chrome stems may be too stiff (i.e., modulus mismatch) and cause stress shielding. • Bearing surfaces: Acetabular liners and femoral head implants. Polyethylene (PE) liner and cobalt-chrome (Co-Cr) femoral head currently most common. Ceramic and metal also used. ‫ ؠ‬UHMWPE (ultra high molecular weight PE): good surface, but high wear rates and debris lead to aseptic loosening. Direct compression molding is preferred manufacturing technique. Sterilization with irradiation in nonoxygen environ- ment promotes cross-linking. Highly cross-linked PE has much better wear rates. ‫ ؠ‬Co-Cr: “supermetal” alloy. Commonly used for femoral bearing surface with PE liner. Metal on metal implants avail- able. Debris particles are much smaller, create less histocytic response. Carcinogenesis is a theoretic concern. ‫ ؠ‬Ceramic (alumina): Excellent wear rates, but brittle (could fracture). Can be used with PE liner or ceramic cup. Techniques • Two types of fixation: 1. Cement, 2. Uncemented/biologic ‫ ؠ‬Cement: Methylmethacrylate. Most often used in elderly patients. Provides immediate static fixation, no remodeling potential. Cement resists compression better than tension. As such, femoral implants do better than acetabular cups with this fixation. 3rd generation cementing techniques: pressurization, precoat stem, centralizer/restrictor, canal preparation, 2mm mantle ‫ ؠ‬Uncemented/biologic: Used in younger patients (increasing popularity). Bone ongrowth or ingrowth—bone grows onto/into implant. Has remodeling potential, gives dynamic fixation. Not good a good choice in post-irradiated hip. • Fixation is NOT immediate, needs initial fixation for stability: 2 techniques. ‫ ؠ‬Press fit: Implant 1-2mm larger than bone. Bone hoop stresses provide initial fixation while bone on/ingrows. ‫ ؠ‬Line to line: Implant and bone are same size. Screws used to provide initial fixation while bone on/ingrows. • Optimal porous ongrowth pore size: 50-150 micrometers. Ongrowth surface area varies. • Current gold standard implant: Uncemented (ingrowth) acetabular cup and cemented femoral steel. Trends are chang- ing, and more uncemented femoral components and alternative bearing surfaces are being used more frequently. • Head size affects stability (larger is more stable) and wear (large head ϭ high volumetric wear). 28mm is optimal size. Indications • Arthritis of hip ‫ ؠ‬Common etiologies: osteoarthritis, rheumatoid arthritis, osteonecrosis, prior pediatric hip disease ‫ ؠ‬Clinical symptoms: groin/hip pain, worse with activity, gradually worsening over time, decreased functional capacity ‫ ؠ‬Radiographic findings: appropriate radiographic evidence of hip arthritis should be present Osteoarthritis Rheumatoid arthritis 1. Joint space narrowing 1. Joint space narrowing 2. Sclerosis 2. Periarticular osteoporosis 3. Subchondral cysts 3. Joint erosions 4. Osteophyte formation 4. Ankylosis ‫ ؠ‬Failed conservative treatment: NSAIDs, activity modification, weight loss, PT, cane (contralateral hand), injections ‫ ؠ‬Other: Fractures (e.g., femoral neck with hip DJD), tumors, developmental disorders (e.g., DDH, etc) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 277

8 Thigh/Hip • DISORDERS Femoral preparation: Trial prosthesis inserted Reduction of hip with Rasp in shape of stem of into femoral canal to ensure prosthesis in place. trial prosthesis used to fit (its collar flush with cut complete channel. surface of femoral neck) TOTAL HIP ARTHROPLASTY—CONTINUED Contraindications • Absolute ‫ ؠ‬Neuropathic joint ‫ ؠ‬Infection ‫ ؠ‬Medically unstable patient (e.g., severe cardiopulmonary disease). Patient may not survive the procedure. • Relative ‫ ؠ‬Young, active patients. These patients can wear out the prosthesis many times in their lives. Alternatives • Considerations: age, activity level, overall medical health • Osteotomy: femoral or pelvic; usually performed in younger patients • Arthrodesis/fusion: young laborers with isolated unilateral disease (i.e., normal spine, knee, ankle, contralateral hip) Procedure • Approaches ‫ ؠ‬Posterior, lateral, and anterolateral approaches ‫ ؠ‬Minimally invasive, one- and two-incision approaches are becoming more common. • Steps ‫ ؠ‬Acetabulum: remove labrum & osteophytes, ream to a cortical rim, implant cup (35-45° coronal tilt, 15-30° anteversion) ‫ ؠ‬Femur: dislocate head, cut neck, remove head, find and broach canal (lateralize as needed)—stem cannot be in varus, implant stem, trial head, & neck. Implant the appropriate head/neck and acetabular liner. Complications • Infection: Diagnose with labs and aspiration. Prevention is mainstay: perioperative antibiotics, meticulous prep/drape technique, etc. Acute/subacute: irrigation & debridement with PE exchange. Late: one- or two-stage revision. • Loosening: Patient often complains of “start up” pain. Radiolucent lines seen on plain radiographs. Most often caused by osteolysis. Osteolysis caused from macrophage response to submicron-sized wear particles (usually PE). • Dislocation: Can be caused from component (either femur or acetabulum) malalignment or soft tissue injury/ dysfunction. Decreased in posterior approach when short external rotators are repaired during closure. • Neurovascular injury ‫ ؠ‬Sciatic nerve: peroneal division (resulting in foot drop) at risk from vigorous retraction in posterior approach ‫ ؠ‬Femoral nerve: with vigorous retraction in anterolateral approach ‫ ؠ‬Obturator vessels: under the transverse acetabular lig., injured with retractors or anteroinferior quadrant cup screw ‫ ؠ‬External iliac vessels: at risk if cup screw placed in anterosuperior quadrant (posterosuperior quadrant is safe) ‫ ؠ‬Medial femoral circumflex artery: under quadratus femoris, at risk in posterior approach if muscle is taken down • Heterotopic ossification: Usually in predisposed patients. Can cause decreased ROM. One dose of XRT can prevent it. • Medical complications: Deep venous thrombosis (DVT) & pulmonary embolus (PE) known risk of THA. Prophylaxis must be initiated. • Periprosthetic fracture of femur ‫ ؠ‬Stable implant: ORIF (plates, cables, ϩ/Ϫ bone graft). ‫ ؠ‬Unstable implant: replace with longer stem that passes fx site. 278 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PEDIATRIC DISORDERS • Thigh/Hip 8 Development dysplasia of hip Normal Hip dislocation Anterior inferior Perkins’ Triradiate cartilage False iliac spine vertical acetabulum line Line of acetabular roof Acetabular >30° index <30° Average Radiograph of 15 month old in newborn 27.5° with DDH showing classic Hilgenreiner’s horizontal line H N S H shortened; signs: increased acetabular S femoral index, a broken Shenton’s line H = Hilgenreiner’s line as a S neck may and a false acetabulum. horizontal line thru the tri-radiate cartilage be above D = Perkin’s line is a vertical Hilgenreiner’s line thru the lateral edge of the acetabulum line N = ossification center of D Femoral Anteversion femoral head, should be in Internal Femoral Torsion inner lower quadrant. Testing S = Shenton’s curved line (broken for in hip dislocation) femoral Pavlik harness torsion Harness adjusted to In standing With feet turned max- With feet turned max- allow comfortable position, imally inward, knees imally outward, knees abduction within safe knees and point directly medially so rotate only slightly zone. Forced abduction feet point that they face each other beyond neutral position beyond this limit may inward lead to avascular necrosis of femoral head. Posterior strap serves as checkrein to prevent hip from adducting to point of redislocation. DESCRIPTION EVALUATION TREATMENT DEVELOPMENTAL DYSPLASIA OF THE HIP (DDH) • Abnormal hip development result- Hx: Usually unnoticed by parents. Obtain & maintain concentric ing in dislocation, subluxation, or ϩ/Ϫ risk factors laxity of hip PE: Barlow (dislocation), ϩ Ortolani reduction: (relocation), ϩ/Ϫ Galeazzi test & de- ‫ ؠ‬0-6mo: Pavlik harness • Most from capsular laxity & posi- creased abduction ‫ ؠ‬6-24mo: Closed reduction, spica tioning; irreducible teratologic form XR: Useful after 6mo (femoral head seen in congenital syndromes or begins to ossify). Look for position cast; open reduction if CR fails neuromuscular diseases. in acetabulum. Multiple radiographic ‫ ؠ‬2-4yr: Open reduction with or lines help evaluate hip. • Risk factors: female, breech, first US: Useful in neonate. Alpha angle without femoral osteotomy born, family hx, decreased uterine Ͼ60 is nl. ‫ ؠ‬Ͼ4yr: Acetabular osteotomy; ter- space conditions atologic hips need open treat- • Early diagnosis and treatment essential ment COMPLICATIONS: Osteonecrosis of femoral head: can occur during reduction or from nonanatomic positioning postreduction. FEMORAL ANTEVERSION • Internal rotation of femur, femoral Hx: Usually presents 3-6yr 1. Most spontaneously resolve anteversion does not decrease properly PE: Femur IR (IRϾ65°), patella points 2. Derotational osteotomy if it persists • #1 cause of intoeing medial, intoeing gait past age 10 (mostly cosmetic) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 279

8 Thigh/Hip • PEDIATRIC DISORDERS Slipped Capital Femoral Epiphysis Slipped Capital Femoral Legg-Calve-Perthes Disease Epiphysis: Best diagnostic sign is physical examination. Operative Fixation With patient supine, as thigh is flexed it rolls into external rotation and abduction Frog-leg radiograph, Threaded cannulated screw which demonstrates introduced over guide wire slipped epiphysis more clearly, always Young girl walking in Atlanta Scottish Rite indicated when Children’s Hospital brace. Advantages of disorder is suspected brace: allows child to walk without support, allows for further abduction by telescoping bar, and permits free knee and ankle motion DESCRIPTION EVALUATION TREATMENT LEGG-CALVE-PERTHES DISEASE • Idiopathic osteonecrosis of femoral Hx: Boys (4:1), usually 4-8y.o. Limp • Goals: 1. Relieve pain symptoms; head with hip, thigh, or knee pain. No 2. Maintain/obtain full ROM; trauma. 3. Contain femoral head • Femoral head must revascularize, PE: Decr. ROM (esp. IR & abduction) can take 2-5yr to complete XR: AP/lateral hip: sclerosis in early • Traction, reduced weight-bearing stages. “Crescent sign” sign of sub- • ROM: rest, traction, ϩ/Ϫ therapy • Prognosis good with onset Ͻ6yo chondral collapse/fx • Osteotomy: femoral or acetabular & minimal lat. pillar involvement MR: Will show early necrosis when plain x-rays are still normal. usually reserved for older patients • Catterall & Herring classifications • Poor healing results in hip OA as adult SLIPPED CAPITAL FEMORAL EPIPHYSIS (SCFE) • Displacement (“slip”) of femoral Hx: 10-16y.o., obese, limp, hip or • Percutaneous in situ screw fixation epiphysis through the proximal knee pain, ϩ/Ϫ weight bear (WB) • One cannulated screw is gold stan- physis PE: Decr. ROM (esp. IR), hip ER with flexion, antalgic gait (if able to WB) dard • Classification: Stable: able to bear XR: AP/lateral: BOTH hips, will show • Progressive slip may still occur weight (WB); Unstable: unable to WB slip; Klein’s line should intersect • Forceful reduction NOT recom- epiphysis. Graded on percent of • Associated with obesity, renal & epiphysis that slipped: Gr 1:Ͻ33%, mended thyroid disease Gr 2: 33-50%, Gr 3: Ͼ50% • Prophylactic pinning of contralateral • Epiphysis is usually posterior to side is common and supported neck but remains in acetabulum. COMPLICATIONS: Osteonecrosis (50% in unstable slips), chondrolysis, early osteoarthritis TRANSIENT SYNOVITIS • Aseptic hip effusion of unknown Hx: Ages 2-5y.o., MϾF, insidious on- • Aspirate hip under anesthesia with cause set limp fluoroscopy if PE & labs indicate PE: Decreased ROM (esp. abd), antal- infection • May be caused by post viral syn- gic gait drome or overuse XR: r/o other hip pathology • Septic hip requires I&D and antibi- LABS: CBC, ESR, blood culture otics • Common cause of hip pain & limp US: Evaluate for effusion (if suspect • Diagnosis of exclusion, r/o septic septic hip) • Transient synovitis resolves: 2-10 days hip • Observation, rest, ϩ/Ϫ NSAIDs 280 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

SURGICAL APPROACHES • Thigh/Hip 8 Anterior Approach to Hip Gluteus medius Sartorius (retracted) Rectus femoris Ascending br. lateral femoral circumflex artery and vein Tensor fasciae latae (retracted) Sartorius Anterior capsule (retracted) Rectus femoris (cut) Ascending br. lateral femoral circumflex artery and vein Rectus femoris (cut) Tensor fasciae Femur latae (retracted) Anterior capsule Gluteus medius (retracted) USES INTERNERVOUS PLANE DANGERS COMMENT Open reduction ANTERIOR (SMITH-PETERSON) APPROACH TO HIP • Retract LFCN anteriorly ‫ ؠ‬Pediatric congenital • Ascending branch of hip dislocation Superficial • Lateral femoral ‫ ؠ‬Adult anterior dislo- • Sartorius (femoral nerve) cutaneous n. LFCA must be ligated in cations • Tensor fasciae latae (SGN) approach • Femoral nerve • Take down both heads of Irrigation & debridement Deep • Ascending branch rectus femoris to expose Fractures: anterior femo- • Rectus femoris (femoral n.) joint ral head (ORIF) • Gluteus medius (SGN) of lateral femoral • Vigorous medial retrac- Hemiarthroplasty circumflex artery tion can injure femoral Tumor excision nerve MEDIAL (LUDLOFF) APPROACH TO HIP Pediatric hip dislocation • Used most in pediatric Adductor or psoas re- Superficial: Intermuscular plane • Obturator nerve cases lease • Adductor longus (obturator n.) (ant. division) Irrigation & debridement • Gracilis (obturator n.) • Good access to trans- • Medial femoral cir- verse acetabular liga- Deep cumflex artery ment & psoas tendon, • Adductor brevis (obturator n.) which can block closed • Adductor magnus (obturator & • Obturator nerve hip reduction. Poor ac- (post. division) cess to acetabulum. sciatic n.) • External pudendal artery (proximally) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 281

8 Thigh/Hip • SURGICAL APPROACHES Anterolateral (Watson-Jones) Approach to Hip Joint Anterior capsule Rectus femoris Tensor fasciae latae Gluteus medius Vastus lateralis Greater trochanter Lateral (Transtrochanteric) Approach to Hip Joint Incision Gluteus maximus Gluteus medius site (retracted) (split and retracted) Greater Femoral head trochanter Joint capsule Fascia lata Gluteus Greater Gluteus medius maximus trochanter (split and retracted) Joint Tensor fasciae capsule latae Femoral Vastus head lateralis Acetabulum USES INTERNERVOUS PLANE DANGERS COMMENT • Total hip arthro- ANTEROLATERAL (WATSON-JONES) APPROACH TO HIP plasty Intermuscular plane • Descending branch of • Must detach abductors (either oste- • Hemiarthroplasty • Tensor fasciae latae LFCA (under rectus otomy or extensive release) • ORIF of proximal femoris) (SGN) • Vigorous medial retraction can injure femur fxs • Gluteus medius (SGN) • Femoral nerve femoral nerve • Total hip arthro- LATERAL (HARDINGE) APPROACH TO HIP plasty (not used for revisions) • Split gluteus medius • Superior gluteal artery • No osteotomy of greater trochanter (superior gluteal n.) • Femoral nerve required; less dislocation risk • Femoral artery & vein • Split vastus lateral n. • Superior gluteal nerve • Split gluteus medius 1⁄3 anterior, 2⁄3 distally (femoral n.) posterior; release minimus 282 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

SURGICAL APPROACHES • Thigh/Hip 8 Posterior (Southern) Approach to Hip Joint Incision Gluteus maximus site muscle (retracted) Short external Piriformis rotators Gluteus Superior gemellus medius Obturator (retracted) internus Inferior gemellus Joint capsule Gluteus maximus (retracted) Gluteus Sciatic Sciatic Greater maximus nerve nerve trochanter (split and retracted) Quadratus Medial femoral femoris circumflex artery and obturator externus Greater trochanter Posterior Short external rotators Femoral head Anterior USES INTERNERVOUS PLANE DANGERS COMMENT • Total hip arthroplasty POSTERIOR (MOORE/SOUTHERN) APPROACH TO HIP • Reflecting piriformis pro- • Hemiarthroplasty tects sciatic nerve • Fractures/ORIF Split gluteus maximus • Sciatic nerve • Posterior hip dislocation (inferior gluteal n.) • Inferior gluteal artery • IGA injured in proximal • Medial femoral circum- extension flex artery (under qua- • Repair short ERs to pre- dratus femoris) vent dislocation NETTER’S CONCISE ORTHOPAEDIC ANATOMY 283

8 Thigh/Hip • SURGICAL APPROACHES Lateral Approach to Thigh (Femur) Hip Arthroscopy Portals Vastus lateralis Femur (split and retracted) Vastus lateralis Posterolateral Anterolateral (split and portal portal retracted) Periosteum (opened) Femur Incision may be extended proximally and distally to expose entire femur Incision site Fascia lata Anterior portal Vastus lateralis USES INTERNERVOUS PLANE DANGERS COMMENT THIGH FASCIOTOMIES See page 269. LATERAL APPROACH TO THIGH • Fractures Split vastus lateralis (femo- • Descending branch of lateral • Incision can be large or small; • Tumors ral nerve) or elevate it off femoral circumflex artery made along line between greater intermuscular septum trochanter and lateral condyle • Perforates from profunda femoris • Arteries (at left) encountered or require ligation • Superior lateral geniculate a. HIP ARTHROSCOPY PORTALS • Arthroscopy used for diagnosis, labral tears, loose body removal, synovectomy, irrigation, and debridement Anterior Intersection of vertical line 1. Lateral femoral cutaneous n. Second portal. Angle 45° cephalad, from ASIS and horizontal 2. Femoral nerve 30° to midline. Pierce sartorius & line from tip of GT 3. Ascending branch of LFCA rectus before capsule Anterolateral Anterior tip of greater 1. Superior gluteal nerve Safest portal, establish 1st. Pierce trochanter (GT) gluteus medius & lateral capsule Posterolateral Posterior tip of greater 1. Sciatic nerve Last portal. Pierce gluteus medius/ trochanter (GT) minimus • Long cannulae, arthroscope, instruments, and traction are needed for hip arthroscopy. 284 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Topographic Anatomy CHAPTER 9 Osteology Radiology Leg/Knee Trauma Joints 286 Minor Procedures 287 History 290 Physical Exam 292 Origins and Insertions 296 Muscles 306 Nerves 307 Arteries 308 Disorders 314 Pediatric Disorders 315 Surgical Approaches 320 322 323 332 335

9 Leg/Knee • TOPOGRAPHIC ANATOMY Quadriceps Vastus Gracilis Biceps femoris vastus lateralis medialis tendon muscle muscle muscle Long head Iliotibial Quadriceps Short head tract tendon Popliteal Lateral Patella Great fossa retinaculum saphenous Medial vein Gastrocnemius Lateral retinaculum muscle joint line Semi- Medial membranosus Medial head Fibular joint line muscle Lateral head head (superficial Patellar posterior Fibularis tendon compartment) (peroneus) longus Tibial Small muscle tuberosity saphenous vein Gerdy’s Great saphenous Lateral tubercle vein compartment Tibialis Pes anserinus Fibularis anterior muscle and bursa (peroneus) longus Lateral and brevis tendons compartment Anterior border of tibia Lateral malleolus Anterior compartment Calcaneal (Achilles) Lateral tendon malleolus Medial malleolus Medial malleolus STRUCTURE CLINICAL APPLICATION Iliotibial tract (band) Tightness can cause lateral knee and/or thigh pain. Quadriceps muscle Atrophy can indicate an injury and/or contribute to knee pain. Quadriceps tendon Can rupture with eccentric loading. Defect is palpated here. Patella Tenderness can indicate fracture; swelling can be prepatellar bursitis. Patellar tendon Can rupture with eccentric loading. Defect is palpated here. Patellar retinaculum Patellar femoral ligaments palpated here. They can be injured in patellar dislocation. Joint line Plicae can also be palpated here. Tibial tubercle Tenderness here can indicate meniscal pathology. Pes anserinus & bursa Tender in Osgood-Schlatter disease. Gerdy’s tubercle Insertion of medial hamstrings. Bursitis can develop. Site of hamstring tendon harvest. Popliteal fossa Insertion of the iliotibial tract (band). Muscle compartments Popliteal artery pulse can be palpated here. Will be firm or tense in compartment syndrome. Anterior most common. 286 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OSTEOLOGY • Leg/Knee 9 Lateral Adductor Lateral epicondyle tubercle epicondyle Lateral Medial Lateral condyle epicondyle condyle Medial condyle Trochlear groove Intercondylar fossa Superior pole Odd facet Lateral facet Anterior Medial facet Lateral facet Medial facet Posterior Inferior pole Anterior view Posterior view Superior view CHARACTERISTICS OSSIFY FUSE COMMENTS • Distal femur—2 condyles DISTAL FEMUR ‫ ؠ‬Medial: larger, more posterior ‫ ؠ‬Lateral: more ant. & proximal Secondary • Condyles: rounded posteriorly (for flexion) and flat Distal Birth 19yr anteriorly (for standing) • Trochlear groove: a depression physis ‫ ؠ‬Epicondyle: origin of collateral ligaments between the condyles anteriorly ‫ ؠ‬Epicondylar axis and/or post. condylar axis for patella articulation used to determine femur rotation (e.g., in TKA) • Intercondylar notch: between • Sulcus terminale: groove in lateral condyle. Infe- condyles, site of cruciate origins rior to groove, it is weight-bearing portion of condyle. • Ovoid shaped, inf. & sup. poles • Triangular in cross section • Adductor tubercle: insertion of adductor magnus • 2 facets (larger lateral & medial) • Distal femoral physis: grows approx. 7mm/yr separated by a central ridge PATELLA ‫ ؠ‬Each facet is subdivided into Primary 3yr 11-13yr • Largest sesamoid bone in body superior, middle, inferior facets (single center) • Bipartite patella: failure of superolateral portion ‫ ؠ‬Odd facet (7th sub-facet) is to fuse. It is often confused with a fracture. far medial on medial facet • Functions: 1. Enhances quadriceps pull (as fulcrum); 2. Protects knee; 3. Enhances knee lubrication • Contact point on patella moves proximally w/flexion • Odd facet articulates in deep flexion • Has thickest articular cartilage (up to 5mm) NETTER’S CONCISE ORTHOPAEDIC ANATOMY 287

9 Leg/Knee • OSTEOLOGY Bones of Anterior view Posterior view right leg Intercondylar eminence Intercondylar eminence Lateral intercondylar Lateral intercondylar Medial intercondylar tubercle tubercle tubercle Anterior intercondylar Medial intercondylar area (ACL insertion) tubercle Posterior Superior articular surfaces Lateral condyle intercondylar (medial and lateral facets) Apex, Medial area Head, condyle (PCL fovea) Lateral condyle Neck Gerdy’s tubercle of fibula (insertion of Soleal line Apex, iliotibial tract) Head, Lateral surface Oblique line Interosseous Neck of fibula border Groove for insertion of Anterior border Tibial tuberosity Posterior semimembranosus surface tendon Interosseous border Lateral surface Nutrient foramen Medial surface Anterior border Posterior surface Interosseous border Medial border Medial crest Medial surface Medial border Tibia Lateral surface Fibula Tibia Groove for tibialis posterior and Lateral malleolus Medial flexor digitorum Fibula malleolus longus tendons Posterior Medial border malleolus Fibular notch Articular facet of Articular facet of Articular facet of Lateral malleolus lateral malleolus medial malleolus medial malleolus Malleolar fossa of lateral malleolus Inferior articular surface (plafond) Inferior articular surface (plafond) CHARACTERISTICS OSSIFY FUSE COMMENTS 18 yr • Long bone characteristics TIBIA 18-20yr • Lateral plateau fx more common • Proximal end: plateau (canc.) • Osgood-Schlatter: traction apophysi- Primary: Shaft 7wk 20yr ‫ ؠ‬Medial plateau: concave (fetal) 18-22yr tis at open tibial tubercle apophysis ‫ ؠ‬Lateral plateau: convex • Tubercle: patellar tendon insertion ‫ ؠ‬7-10° posterior slope Secondary 9mo • IM nail insertion point proximal to • Tubercle: 3cm below joint line 1. Proximal epiphysis 1yr • Eminence: medial & lateral 2. Distal epiphysis tibial tubercle tubercles (spines) 3. Tibial tuberosity • Tibial spine avulsion fx of ACL (peds) • Shaft: triangular cross section • Gerdy’s tubercle on proximal tibia: • Distal end: pilon (cancellous) Primary: Shaft FIBULA ‫ ؠ‬Articular surface: plafond insertion site of iliotibial tract (band) ‫ ؠ‬Distal tip: medial malleolus 7wk • Fibularis incisura: lat. groove for fibula (fetal) • Plafond is roof and medial malleolus • Long bone characteristics • Proximal end: head Secondary is medial wall of ankle mortise 1. Proximal epiphysis 1-3yr ‫ ؠ‬Neck 2. Distal epiphysis 4yr • LCL & biceps femoris insert on head • Shaft: long, cylindrical • Neck has groove for peroneal nerve • Distal end: lateral malleolus • Nerve can be injured in fibula fx • Shaft used for vascularized BG • Lat. mal. is lat. wall of ankle mortise 288 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OSTEOLOGY • Leg/Knee 9 Posterior ligament of fibular head Apex Superior view Posterior intercondylar area (origin Posterior of posterior cruciate ligament) Head Intercondylar eminence Fibula Tibia Anterior ligament Medial condyle of fibular head Superior articular surface (medial facet) Lateral condyle Medial Superior articular Lateral Intercondylar tubercles surface (lateral facet) Tibial tuberosity Anterior Anterior intercondylar area (origin of anterior cruciate ligament) LOWER EXTREMITY ALIGNMENT 3˚ Definitions 6˚ Vertical axis Anatomic axis Line drawn along the axis of the Femoral of femur femur anatomic Knee axis Anatomic axis Line drawn along the axis of the axis 87˚ of tibia tibia Mechanical axis Line drawn between center of fem- Femoral Tibial of femur oral head and intercondylar notch mechanical mechanical and Mechanical axis Line drawn between center of knee axis anatomic axis of tibia and center of ankle mortise Knee axis Line drawn along inferior aspect 81˚ 87˚ of both femoral condyles Vertical axis Vertical line, perpendicular to the ground Lateral distal Angle formed between knee axis femoral angle and femoral axis laterally Medial tibial angle Angle formed between knee axis and tibial axis Relationships Knee axis Parallel to the ground and perpen- dicular to vertical axis Mechanical axis Average of 6° from anatomic axis of femur Approximately 3° from vertical axis Mechanical axis Normally same as anatomic axis of of tibia tibia unless tibia has a deformity Lateral distal 81° from femoral anatomic axis femoral angle 87° from femoral mechanical axis Medial proximal 87° from tibial mechanical axis tibial angle NETTER’S CONCISE ORTHOPAEDIC ANATOMY 289