The aim of this study was to evaluate the long-term clinical
and radiographic outcomes of the Birmingham Interlocking Pelvic
Osteotomy (BIPO). In this prospective study, we report the mid- to long-term clinical
outcomes of the first 100 consecutive patients (116 hips; 88 in
women, 28 in men) undergoing BIPO, reflecting the surgeon’s learning
curve. Failure was defined as conversion to hip arthroplasty. The
mean age at operation was 31 years (7 to 57). Three patients (three
hips) were lost to follow-up.Aims
Patients and Methods
The painful subluxed or dislocated hip in adults
with cerebral palsy presents a challenging problem. Prosthetic dislocation
and heterotopic ossification are particular concerns. We present
the first reported series of 19 such patients (20 hips) treated
with hip resurfacing and proximal femoral osteotomy. The pre-operative
Gross Motor Function Classification System (GMFCS) was level V in
13 (68%) patients, level IV in three (16%), level III in one (5%) and
level II in two (11%). The mean age at operation was 37 years (13
to 57). The mean follow-up was 8.0 years (2.7 to 11.6), and 16 of the
18 (89%) contactable patients or their carers felt that the surgery
had been worthwhile. Pain was relieved in 16 of the 18 surviving
hips (89%) at the last follow-up, and the GMFCS level had improved
in seven (37%) patients. There were two (10%) early dislocations;
three hips (15%) required revision of femoral fixation, and two
hips (10%) required revision, for late traumatic fracture of the
femoral neck and extra-articular impingement, respectively. Hence
there were significant surgical complications in a total of seven
hips (35%). No hips required revision for instability, and there
were no cases of heterotopic ossification. We recommend hip resurfacing with proximal femoral osteotomy
for the treatment of the painful subluxed or dislocated hip in patients
with cerebral palsy.
Metal-on-metal hip resurfacing was performed for developmental dysplasia in 96 hips in 85 patients, 78 in women and 18 in men, with a mean age at the time of surgery of 43 years (14 to 65). These cases were matched for age, gender, operating surgeon and date of operation with a group of patients with primary osteoarthritis who had been treated by resurfacing, to provide a control group of 96 hips (93 patients). A clinical and radiological follow-up study was performed. The dysplasia group were followed for a mean of 4.4 years (2.0 to 8.5) and the osteoarthritis group for a mean of 4.5 years (2.2 to 9.4). Of the dysplasia cases, 17 (18%) were classified as Crowe grade III or IV. There were five (5.2%) revisions in the dysplasia group and none in the osteoarthritic patients. Four of the failures were due to acetabular loosening and the other sustained a fracture of the neck of femur. There was a significant difference in survival between the two groups (p = 0.02). The five-year survival was 96.7% (95% confidence interval 90.0 to 100) for the dysplasia group and 100% (95% confidence interval 100 to 100) for the osteoarthritic group. There was no significant difference in the median Oxford hip score between the two groups at any time during the study. The medium-term results of metal-on-metal hip resurfacing in all grades of developmental dysplasia are encouraging, although they are significantly worse than in a group of matched patients with osteoarthritis treated in the same manner.
