Septic Arthritis of Hip

Septic Arthritis of Hip In Children Duangjai Leeprakobboon Khonkaen Hospital 20 Dcember 2018

Epidemiology– Demographics • incidence – peaks in the first few years of life • age – 50% of cases occur in children younger than 2 years of age– Location • hip joint involved in 35% of all cases of septic arthritis • knee joint involved in 35% of all cases of septic arthritis– Risk factors for neonatal septic arthritis • prematurity (relatively immunocompromised) • Cesarean section • patients treated in the NICU • invasive procedures such as umbilical catheterization, venous catheterization, heel puncture may lead to transient bacteremia

Routes of inoculation– Direct inoculation from trauma or surgery– Hematogenous seeding– Extension from adjacent bone (osteomyelitis) – can develop from contiguous spread of osteomyelitis – often from metaphysis » common in neonates who have transphyseal vessels that allow spread into the joint • Hip • Shoulder • Elbow • Ankle (NOT the knee)

Pathogenesis• Acute septic arthritis (SA) in children is most often a hematogenous infection Krogstad P. Osteomyelitis and septic arthritis. In: Feigin RD, Cherry JD, editors. Textbook of Pediatric Infectious Diseases. 6th ed. Philadelphia, PA: Saunders; 2009. pp. 725–748. Pääkkönen M, Peltola H. Management of a child with suspected acute septic arthritis. Arch Dis Child.2012;97(3):287–292. [PubMed]• The role of trauma in the pathogenesis remains unclear Preceding trauma in childhood hematogenous bone and joint infections.Pääkkönen M, Kallio MJ, Lankinen P, Peltola H, Kallio PE. J Pediatr Orthop B. 2014 Mar; 23(2):196-9.

Microbiology: vary with age• Group B streptococcus – most common in neonates with community-acquired infection – exposed during transvaginal delivery• Staph aureus – most common in children over 2 years of age – most common in nosocomial infections of neonates• Neisseria gonorrhoeae – most common organism in adolescents – patients usually have a preceding migratory polyarthralgia, multiple joint involvement, and small red papules

Microbiology• Group A beta-hemolytic streptococcus – most common organism following varicella infection• Haemophilus – incidence has markedly decreased since the advent of its vaccine• Kingella – best isolated on blood culture media – aged 6–36 months Kingella kingae: carriage, transmission, and disease.Yagupsky P Clin Microbiol Rev. 2015 Jan; 28(1):54-79.

Presentation• Symptoms – acute onset of pain • presents more acutely than osteomyelitis – systemic symptoms • often associated with fever and other systemic symptoms causing toxic appearance – limp or refusal to bear weight• History – recent local trauma or infections – vaccination history must be obtained, particularly with regard to vaccination against Haemophilus influenzae – recent or current antibiotics may mask symptoms

Presentation• Physical exam – vitals • temperature and vital signs to rule out hemodynamic instability – inspection and palpation • localized swelling • effusion, tenderness, and warmth • hip rests in a position of flexion, abduction, and external rotation (FABER) – hip capsular volume is maximized with flexion, abduction, and external rotation and is the position of comfort for hip septic arthritis – range of motion • severe pain with passive motion • unwillingness to move joint (pseudoparalysis)

Presentation• Fever is especially high in cases caused by methicillin-resistant S. aureus (MRSA). Differentiating between methicillin-resistant and methicillin-sensitive Staphylococcus aureus osteomyelitis in children: an evidence-based clinical prediction algorithm.Ju KL, Zurakowski D, Kocher MS. J Bone Joint Surg Am. 2011 Sep 21; 93(18):1693-701.• Cases caused by K. kingae are milder, and fever may even be absent. Differentiating Kingella kingae septic arthritis of the hip from transient synovitis in young children.Yagupsky P, Dubnov-Raz G, Gené A, Ephros M, Israeli-Spanish Kingella kingae Research Group. J Pediatr. 2014 Nov; 165(5):985-9.e1.

RadiographStandard radiographSoft tissue swellingWidening joint space (> 2mm)Capsular distentionSubluxation of the hipBone changes

Ultrasound• Sens 95% for detect excessive fluid in the hip joint• Can be used to guide aspiration• High sensitivity and low specificity – Changes in the surrounding soft tissues• Unable to detect small fluid accumulations in early phase of disease• Cannot differentiate between a septic and a sterile effusion

MRI• Sensitivity 88% - 100%, specificity 75% - 100%, PPV 85%• Better soft tissue resolution• Differentiating : cellulitis, osteomyelitis and tumor• Rule out associated infection of bone or muscle• Gadolinium – R/O neoplasm, fracture, or bone infarct• Disadvantages – Cost – Necessity for sedation

Serum labsKocher et al (1999): four clinical criteria in childwith painful hip Chance to be septic arthritis1 Non weight-bearing Kocher Calrd (modified)2 ESR > 40 mm/hr 4 criteria: 99.6% 5/5 = 97.5%3 Fever (Temp >38.5C) 3 criteria: 93.1% 4/5 = 93.1%4 WBC > 12,000 2 criteria: 40% 3/5 = 82.6% 1 criteria: 3% 2/5 = 62.4% 0 criteria: 0.2% 1/5 = 36.7% 0/5 = 16.9%5 CRP >20 mg/L

Serum labs• CRP ***The most important of the labs – CRP > 2.0 (mg/dl) in combination with refusal to bear weight yields a 74% probability of septic arthritis• Order of sensitivity of above criteria – fever > CRP > ESR > refusal to bear wieght > WBC Sensitivity of erythrocyte sedimentation rate and C-reactive protein in childhood bone and joint infections.Pääkkönen M, Kallio MJ, Kallio PE, Peltola H Clin Orthop Relat Res. 2010 Mar; 468(3):861-6.



Hip aspiration• WBC of >50 000/μL – >75% are polymorphonuclear cells• Cultures may remain negative even in 30–70% of the cases. Culture-negative septic arthritis in children.Lyon RM, Evanich JD. J Pediatr Orthop. 1999 Sep-Oct; 19(5):655-9.



Treatment• Empiric intravenous antimicrobial therapy• Adequate surgical drainage

Antibiotic Treatment Septic Arthritis Antibiotic TreatmentAge Organism Antibiotics<12 mos staphylococcus sp., group B 1st generation cephalosporin streptococci, and gram-negative bacilli6 mos to 5 yrs S. aureus, S. pneumoniae, group A 2nd or 3rd generation streptococci, H. influenzae cephalosporin5-12 yrs S. aureus 1st generation cephalosporin12-18 yrs N. gonorrhoeae, S. aureus oxacillin/cephalosporin

Antibiotic Treatment• First-generation cephalosporins and clindamycin are both suitable, but these should be administered in large doses and 4 times a day as these are time- dependent antibiotics. Clindamycin vs. first-generation cephalosporins for acute osteoarticular infections of childhood--a prospective quasi-randomized controlled trial.Peltola H, Pääkkönen M, Kallio P, Kallio MJ, OM-SA Study Group. Clin Microbiol Infect. 2012 Jun; 18(6):582-9.

Antibiotic Treatment• In regions where prevalence of MRSA strains exceeds 10%,clindamycin is a valid option of treatment if prevalence ofclindamycin-resistant strains remains <10%.• If clindamycin resistance is common, vancomycin is the firstoption of treatment, despite concerns over poor bonepenetration Clinical practice guidelines by the infectious diseases society of america for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children.Liu C, Bayer A, Cosgrove SE, Daum RS, Fridkin SK, Gorwitz RJ, Kaplan SL, Karchmer AW, Levine DP, Murray BE, J Rybak M, Talan DA, Chambers HF, Infectious Diseases Society of America. Clin Infect Dis. 2011 Feb 1; 52(3):e18-55.• Penicillin monotherapy is suitable for Streptococcus pyogenes and S. pneumoniae. Impact of new Clinical Laboratory Standards Institute Streptococcus pneumoniae penicillin susceptibility testing breakpoints on reported resistance changes over time.Mera RM, Miller LA, Amrine-Madsen H, Sahm DF. Microb Drug Resist. 2011 Mar; 17(1):47-52.

Antibiotic Treatment• Children who have received a Haemophilus type b vaccination do not require adjuvant ampicillin or amoxicillin, which in the prevaccination era was often given to all children under 5 years of age Reduced incidence of septic arthritis in children by Haemophilus influenzae type-b vaccination. Implications for treatment.Peltola H, Kallio MJ, Unkila-Kallio L J Bone Joint Surg Br. 1998 May; 80(3):471-3.

Antibiotic Treatment• The antibiotic may be administered orally if the patient is recovering and CRP level is declining• CRP <20 mg/L is a strong indicator of recovery and informs the clinician that the antibiotics can be safely stopped. Clindamycin vs. first-generation cephalosporins for acute osteoarticular infections of childhood--a prospective quasi-randomized controlled trial.Peltola H, Pääkkönen M, Kallio P, Kallio MJ, OM-SA Study Group. Clin Microbiol Infect. 2012 Jun; 18(6):582-9. Pääkkönen M, Kallio MJ, Kallio PE, Peltola H. Sensitivity of erythrocyte sedimentation rate and C-reactive protein in childhood bone and joint infections. Clin Orthop Relat Res. 2010;468(3):861–866. Peltola H, Pääkkönen M, Kallio P, Kallio MJ, OM-SA Study Group Clindamycin vs. first- generation cephalosporins for acute osteoarticular infections of childhood – a prospective quasi-randomized controlled trial.Clin Microbiol Infect. 2012;18(6):582– 589.

Antibiotic Treatment

Operative• Septic Hip Irrigation and Debridement – approach • most commonly one of the following approaches is utilized – anterolateral approach to the hip – anterior approach through the Smith-Peterson interval – technique • arthrotomy is performed to remove all purulent fluid and to irrigate the joint • intra-articular drain placement is recommended – postoperative care • range of motion exercises of the affected joint may be started within the first few days after surgery

• Although traditionally open arthrotomy was recommended for hip arthritis, several publications have shown mini-invasive methods to be a safe alternative. – repeated ultrasound-guided aspirations – medial portal for hip arthroscopy Givon U, Liberman B, Schindler A, Blankstein A, Ganel A. Treatment of septic arthritis of the hip joint by repeated ultrasound-guided aspirations. J Pediatr Orthop. 2004;24(3):266–270. Edmonds EW, Lin C, Farnsworth CL, Bomar JD, Upasani VV. A medial portal for hip arthroscopy in children with septic arthritis: a safety study. J Pediatr Orthop. 2016 Sep 3; Epub.

• Dexamethasone can be administered to reduce inflammation and may lead to slightly shorter hospital stay.• Nonsteroidal anti-inflammatory agents are administered for pain relief. Fogel I, Amir J, Bar-On E, Harel L. Dexamethasone therapy for septic arthritis in children. Pediatrics.2015;136(4):e776–e782.

Complications• Femoral head destruction• Deformity – physeal damage leads to late angular deformity and leg length discrepancy• Joint contracture• Hip dislocation• Growth disturbance• Limb-length discrepancy• Gait abnormalities• Osteonecrosis• A long follow-up of 1–2 years may be required to detect all possible sequelae

Conclusion• All children presenting with symptomatic joint and fever should be suspected to have septic arthritis.• Diagnosis is confirmed by a joint puncture, and a sample for bacteriology is obtained before intravenous antibiotics are administered.• Intravenous course is continued for 2–4 days until recovery is observed.• A total course of 2 weeks is sufficient in uncomplicated cases.• Open arthrotomy