Abstract
Purpose
In children presenting with irritable hip symptoms we wished to determine the incidence of hip septic arthritis, pathogen characteristics and the functional outcome.
Methods
Between May 2007 and January 2010, children presenting to our institution with irritable hip symptoms were eligible to participate. Exclusion criteria were history of trauma to the hip, systemic inflammatory diseases. Data collected included; demographics, clinical symptoms, temperature, haematological profile, ultrasound and culture reports, microorganism isolated and outcome. The minimum follow up was 6 months (6–24).
Results
Out of 210 children, 199 (135 males) met the inclusion criteria (mean age 5.3 years (0.15–15)). On U/S 72 children had a positive result for hip effusion. 60 children required admission and 41 cases had arthrotomy and washout, with a mean WCC of 10.4 × 10∗9/L (4.85–15.8) and CRP of 118(< 5 to 312). The mean length of hospital stay was 4.4 days (1–32). 25 of the samples cultured showed no growth, 3 of which were positive for gram+cocci on staining. The remaining 16 grew staphylococcus aureus, sensitive to flucloxacillin. 4 cases had positive radiological signs of disease sequelae on follow-up imaging (1 grade II heterotrophic ossification of the hip, 1 minor degenerative changes and 2 major avascular necrosis of the femoral head). Functional sparing was common among this group of cases with preservation of excellent function in all but the 2 cases with major avascular necrosis, which had good/fair function, with 1 and 1.5cm leg length discrepancy.
Conclusion
Of 210 consecutive patients, 41 (20.6%) cases required hip arthrotomy and 19 (9.5%) had a positive culture with 2 cases of functional limitation. The most common pathogen isolated was staph. aureous. K. kingae species, which cannot be cultured by standard methods, was isolated from 1 case, highlighting the need for culturing hip aspirates in blood vials in all cases.
