Periacetabular osteotomy (PAO) is an established treatment for acetabular dysplasia. It has also been proposed as a treatment for patients with acetabular retroversion. By reviewing a large cohort, we aimed to test whether outcome is equivalent for both types of morphology and identify factors that influenced outcome. A single-centre, retrospective cohort study was performed on patients with acetabular retroversion treated with PAO (n = 62 hips). Acetabular retroversion was diagnosed clinically and radiologically (presence of a crossover sign, posterior wall sign, lateral centre-edge angle (LCEA) between 20° and 35°). Outcomes were compared with a control group of patients undergoing PAO for dysplasia (LCEA < 20°; n = 86 hips). Femoral version was recorded. Patient-reported outcome measures (PROMs), complications, and reoperation rates were measured.Aims
Methods
Assessing femoral head coverage is a crucial element in acetabular surgery for hip dysplasia. Plain radiographic indices give rather limited information. We present a novel CT-based method that measures the fraction of the femoral head that is covered by the acetabulum. This method also produces a direct image of the femoral head with the covered part clearly represented, and it also measures acetabular inclination and anteversion. We used this method to determine normal coverage, and applied it to a prospective study of patients with hip dysplasia undergoing periacetabular osteotomy. Twenty-five normal and 26 dysplastic hips were studied. On each CT scan points were assigned on the femoral head surface and the superior half of the acetabular rim. The anterior pelvic plane was then defined, and the pelvis was aligned in that plane. Using our custom software programme, the fraction of the head that was covered was measured, in addition to acetabular inclination and anteversion. In the normal hips femoral head coverage averaged 73% (SD 4). In the same group, mean anteversion was 15.7° (SD 7°), whereas mean inclination was 44.4° (SD 4°). In the dysplastic group femoral head coverage averaged 50.3% (SD 6), whereas mean anteversion and inclination were 18.7° (SD 9°) and 53.2° (SD 5°) respectively. This is the first study to our knowledge that has used a reliable measurement technique of femoral head coverage by the acetabulum in the normal hip. When this is applied to assessing coverage in surgery for hip dysplasia it allows a clearer understanding of where the corrected hip stands in relation to a normal hip. This would then allow for better determination of the likely outcome of this type of surgery. We are presently conducting a prospective study using this technique to study dysplastic hips pre- and post-periacetabular osteotomy.
With regard to functional activity, 21% of patients in both the groups scored 8 or more on the UCLA activity scale. 21% of patients in the BHR and 14% in the Furlong group scored 3 or more on the Tegner activity scale
A prospective study on total knee replacement in patients with Juvenile Idiopathic Arthritis was carried out. There were 31 knee replacements in 17 patients; 12 were female. Bilateral procedures were performed in 11 patients; 10 staged during a single admission and 1 performed in a single procedure. The mean age was 19 years (range, 14–26), and the mean follow-up was 23 months (range, 6–44). The surgery was complicated in 9 cases by a previous distal femoral osteotomy. The results were assessed using the Hospital for Special Surgery (HSS) scoring system. A cruciate sacrificing implant was used in all cases, and the patella was resurfaced in 25/31. The pre-operative mean arc of motion was 62° (range 10°–90° ) and this averaged 89° (range, 20° –115°) at latest follow-up. The pre-operative mean fixed flexion 17° (range, 0° –15° ). The mean pre-operative HSS score was 36 (range, 8–59), and the mean at latest follow-up was 81 (range, 67–95). There has been no sign of aseptic loosening on serial radiographs over the follow-up period. One patient developed a deep infection at 20 months requiring a 2-stage revision and one patient developed a perforated duodenal ulcer postoperatively. The clinical results are very satisfactory, allowing patients to regain their mobility and independence. The early radiographic results are very encouraging despite the poor bone quality and severe deformities that require correction.