Treatment of developmental dislocation of hip: does changing the hip abduction angle in the hip spica affect the rate of avascular necrosis of the femoral head?

Avascular necrosis (AVN) of the femoral head is a serious complication in the management of developmental dislocation of the hip. Increasing the abduction angle increases its stability but compromises the vascularity of the femoral head. From our database of 240 children treated for developmental dislocation of hip by the two senior authors between 1998 and 2008, we defined two groups of children who underwent closed or medial open reduction of the hip after a failed Pavlik treatment or if patients presented late. In group 1, the reduced hip was immobilized in around 90° flexion, 60° abduction, and 0-10° internal rotation. In group 2 the hip was immobilized in around 45° of hip abduction with flexion and internal rotation as before. The first and second authors independently analysed these two groups blinded to the hip abduction angle. Our hypothesis was that a reduction in the hip abduction angle would reduce the incidence of AVN in the second group without compromising the stability. All eligible children were included, and there were 42 children in group 1 and 44 children in group 2. An almost equal number of children underwent closed and medial open reduction in both the groups. The age at reduction was a mode of 6 months (range 6-13 months) and 7 months (range 7-12 months), respectively. The abduction angle in the first group had a mode of 60° (range 52-70°) and the second group had a mode of 45° (range 38-50°). Radiographic evidence of AVN as described by Salter and colleagues was seen in eight children (19%) in the first group and seven children (16%) in the second group (P=0.78). Redislocation occurred in one child in the second group and none in the first group. In summary, the results show a nonsignificant reduction in the incidence of AVN when the hip abduction angle was reduced with no significant increased risk of redislocation.

The Birmingham hip resurfacing prosthesis: an independent single surgeon's experience at 7-year follow-up.

An independent single surgeon's 7-year experience with Birmingham hip resurfacing is presented. The study also involved investigation of the significance of pedestal sign in patients requiring revision. A consecutive 117 hips in 101 patients (59 male and 42 female patients) operated on by the senior author (VGJ) were assessed at a mean follow-up of 7 years (range, 5-9.4 years). Mean age at surgery was 54 years (range, 20-74 years). Seventy-three hips had a preoperative diagnosis of primary osteoarthritis, and secondary osteoarthritis was seen in 44 hips. Failure was defined as revision for any reason. Revision of the femoral component alone was undertaken in 8 hips (6.8%): 5 within first year for periprosthetic fracture neck of femur and in 3 hips after 5 years of follow-up. In 2 patients who were known to have osteonecrosis of the femoral head preoperatively, the femoral component progressively collapsed into varus after 5 years of follow-up. Pedestal sign was the earliest radiologic sign noted in these 2 patients and progressed rapidly within 1 year on serial radiographs well before the onset of clinical symptoms. Kaplan-Meier survival with revision as end point at 7 years was 91.5% (95% confidence interval, 97.6%-85.4%).

Long-term outcome in patients with combined spinal and pelvic fractures.

The outcome of 30 patients with combined spinal and pelvic fractures (C group) was retrospectively investigated and compared with matched group of similar number of isolated spinal fractures (S group) and isolated pelvic fractures (P Group), admitted to our institution between Jan 1998 and May 2002, following a high-energy trauma. After a mean follow-up of 57 months their outcomes were studied using EuroQol questionnaire and return to work status. The EQ-5D scores for patients in the S group were 0.71 (SD 0.29) compared to 0.60 (SD 0.14) for patients in the P group and 0.63 (SD 0.23) for patients in the C group. The EQ-VAS scores were similarly favourable towards patients in the S group. Seventy percent of patients in the S group returned to their previous level of employment after a mean duration of 5.3 months compared to 55% in the P group and 57% in the C group after a mean duration of 9.4 months and 12.8 months, respectively. Patients with isolated spinal fractures had an overall satisfactory outcome compared with patients in the other 2 groups. However, no difference was noted while analysing the outcomes in the later 2 groups (p<0.05), suggesting that the pelvic fracture contributes to the poor outcome, and the presence of a spinal fracture does not influence the long-term outcome. However, problems related to associated injuries and motor neurological deficits have profound confounding effect on the outcome in all 3 groups.