Purpose. The importance of femoral head-neck morphology in the development of early hip osteoarthritis is recognized in femeroacetabular impingement (FAI), however no studies have examined FAI morphology in the developing hip, i.e. pre-closure of the proximal femoral physis. We developed a pilot project to study prevalence of CAM-type FAI hip morphology in both the pre- and post-closure proximal femoral physes of asymptomatic children using MR-imaging. We also examined biologic markers possibly related to FAI etiology, including Vitamin D metabolites, BMI, family history, and activity levels. Method. Recruitment included volunteers with asymptomatic lower extremities, and either pre- or post-closure of the proximal femoral physis. Males were 10–12 years (pre-closure) or 15–18 years (post-closure); females were 8–10 years or 14 18 years. Phlebotomy and urine sampling were used to assess metabolic markers. MRI of bilateral hips and a clinical exam including hip impingement tests were conducted. MR imaging assessment was independent and blinded and recorded using established parameters including alpha angles measured at both the 3:00 (anterior head-neck junction) and 1:30 (antero-superior head-neck junction) radial image positions. Results. Fifty-two volunteers were recruited (32 boys, 20 girls), of whom 44 had bilateral hips imaged (88 hips). Radiographic analysis showed no CAM-type morphology in pre-closure hips and 14% in post-closure hips, using established criteria (alpha > 50.5). The difference between alpha angle measurements at 3:00 and 1:30 positions (5.16) appears significant in developing hips. Conclusion. Results confirm our ability to recruit a cohort of asymptomatic children for the proposed methodology. Collected data found FAI in 14% of the closed-physes group and 0 % in the open physes group suggesting possible physeal closure importance. The difference between 3:00 and 1:30 alpha angle measurements was significantly less than in published adult figures, further suggesting a developmental role in CAM-Type FAI. This is the first published attempt to assess CAM-type FAI morphology in the developing hip. Preliminary data suggests the period just prior to physeal closure may have significant etiological implications. New parameters for imaging angles are suggested. The study results will guide future cohort study designs

Introduction. Paediatric hip fracture accounts for less than one percent of paediatric fractures. Previous studies report complication rates between 20 and 92%. Method. We retrospectively identified patients with fixation for neck of femur fractures at Birmingham Children's Hospital. All patients were under age sixteen. Data were reviewed over a 10 year period (1997-2006). Fractures were classified by Delbet's classification and Ratliff's system to grade avascular necrosis (AVN). Function was assessed using Ratcliff's criteria, incorporating clinical examination and radiographic findings. Results. 15 femoral neck fractures were treated in 14 patients over a ten year period (R=1997-2006). One patient sustained bilateral fractures. Three patients had osteogenesis imperfecta and one osteopetrosis. Mean age at injury was 10.3 years (R=6-14 years). Mean follow-up was 31 months (R=6-110 months). Two fractures were Delbet type-I (13.3%), four type-II (26.7%), six type-III (40%) and three type-IV fractures (20%). Associated injuries included calcaneal fracture, head injury, pubic rami, acetabular and tibial fractures, hip dislocation, and depressed skull fracture with extradural haematoma. Eleven patients were operated on within 24 hours (R=4-19 hours) and four after 24 hours (R=2-11 days). One patient operated on within seven hours had a poor outcome. Premature physeal closure (PPC) occurred in all patients with physeal penetration (Fishers Exact test: p=0.077). The results were ‘good’ in 14 patients (93%) and ‘poor’ in one patient with Ratliff's Type I avascular necrosis (6.7%). This 13 year old male sustained a Delbet type 1 fracture with dislocation of the femoral epiphysis after a road traffic accident. The AVN and PPC rates were 6.7% and 33%. Coxa vara was diagnosed in two patients. One patient developed a significant leg length discrepancy (>2cm). Superficial wound infections occurred in two patients. No non-unions occurred. Conclusion. Complication rates are lower than historical studies

Slipped upper femoral epiphysis (SUFE) is an uncommon condition with potentially severe complications including avascular necrosis (AVN) and chondrolysis. Children with a ‘slip’ are at a significantly higher risk of a contralateral slip. Controversy remains as to when to undertake prophylactic pinning. The primary aim of this study was to assess the Posterior Sloping Angle (PSA, as described by Barrios et al in 2005) as a predictor for contralateral slip in a large, multi ethnic cohort. All consecutive patients treated for SUFE presenting to Waikato Hospital between January 2000 and December 2009 were identified via medical coding. Patients without radiographs and those with bilateral slips on presentation were excluded. Clinical records were reviewed to document demographic data, slip characteristics and follow up outcomes. Radiographic analysis of the PSA in the unaffected hip was performed by a single author. Statistical analysis was performed using a student's t-test with Microsoft Excel 2003. 182 patients were identified, 50 were excluded [26 bilateral slips, 24 no radiograph available] to total a study population of 132 patients. 93 patients were male [72%]. Mean age was 11.8 years [6.2–15.6 years]. 72% were of Maori ethnicity and 26% were of New Zealand European descent. 90 patients [69%] had a unilateral slip, 42 [32%] had a contralateral slip. 48% were not followed until physeal closure and 50% did not attend at least one scheduled appointment Mean PSA of those with a unilateral slip was 10.8° [2–21°]. Patients who subsequently developed a contralateral slip had a statistically significantly higher mean PSA of 17.2° [6–36°] [p<0.0001]. Children with a contralateral slip were significantly younger 11.1 years than those with a unilateral slip 12.2 years (p<0.0001). No significant differences in PSA were found between Maori and NZ European children. If a PSA of 14° was used as an indication for prophylactic fixation in this population 35/42 [83.3%] of contralateral slips would have been prevented. 19/90 hips would have been pinned unnecessarily. The number needed to treat demonstrates that 1.79 hips are prophylactically pinned to prevent one slip in this population. This large retrospective cohort study demonstrates that a PSA of 14° in an unaffected hip after one sided SUFE could warrant prophylactic pinning in an unaffected hip to prevent subsequent slip and the complications associated with this, potentially protecting a population that can be difficult to follow up