Are cam and pincer deformities as common as dysplasia in Japanese patients with hip pain?

In Japan, osteoarthritis (OA) of the hip secondary to acetabular dysplasia is very common, and there are few data concerning the pathogeneses and incidence of femoroacetabular impingement (FAI). We have attempted to clarify the radiological prevalence of painful FAI in a cohort of Japanese patients and to investigate the radiological findings. We identified 176 symptomatic patients (202 hips) with Tönnis grade 0 or 1 osteoarthritis, whom we prospectively studied between August 2011 and July 2012. There were 61 men (65 hips) and 115 women (137 hips) with a mean age of 51.8 years (11 to 83). Radiological analyses included the α-angle, centre-edge angle, cross-over sign, pistol grip deformity and femoral head neck ratio. Of the 202 hips, 79 (39.1%) had acetabular dysplasia, while 80 hips (39.6%) had no known aetiology. We found evidence of FAI in 60 hips (29.7%). Radiological FAI findings associated with cam deformity were the most common. There was a significant relationship between the pistol grip deformity and both the α-angle (p < 0.001) and femoral head-neck ratio (p = 0.024). Radiological evidence of symptomatic FAI was not uncommon in these Japanese patients.

Rotational acetabular osteotomy in patients forty-six years of age or older: comparison with younger patients.

BACKGROUND: Satisfactory intermediate and long-term results of periacetabular rotational osteotomy for early osteoarthritis secondary to dysplasia of the hip have been reported for patients in the third and fourth decades of life. The purpose of the present study was to examine the usefulness of rotational acetabular osteotomy in patients older than forty-six years of age. METHODS: A retrospective review of two groups of patients who had been treated with a rotational acetabular osteotomy was conducted. The older group consisted of twenty-four patients (twenty-six hips) with early-stage osteoarthritis who had a mean age at the time of surgery of 50.9 years (range, forty-six to fifty-eight years) and a mean duration of follow-up of 8.2 years (range, five to thirteen years), and the younger group consisted of sixty patients (sixty-three hips) who had a mean age at the time of surgery of 34.4 years (range, thirteen to forty-five years) and a mean duration of follow-up of 8.3 years (range, five to fourteen years). Clinical follow-up was based on the system of Merle d'Aubigne and Postel. The center-edge angle, acetabular roof angle, and head lateralization index were measured on radiographs made preoperatively, postoperatively, and at the time of follow-up. Preoperative and postoperative joint congruencies were classified into four grades. RESULTS: Preoperatively, the mean Merle d'Aubigne clinical score was 13.9 points in the older group and 14.1 points in the younger group. In both groups, this score improved significantly to a mean postoperative follow-up score of 16.6 points (p < 0.0001), with no significant difference between the two groups. The mean center-edge angle improved from 3.2 degrees preoperatively to 34 degrees postoperatively (p < 0.0001) in the older group and from -2.1 degrees preoperatively to 34 degrees postoperatively (p < 0.0001) in the younger group. The mean acetabular roof angle improved from 29 degrees to 5.9 degrees (p < 0.0001) in the older group and from 31 degrees to 2.9 degrees (p < 0.0001) in the younger group. The mean head lateralization index improved from 0.67 to 0.64 (p < 0.01) in the older group and from 0.66 to 0.61 (p < 0.0001) in the younger group. Progression of osteoarthritis was observed radiographically at the time of follow-up in five hips in the older group and in four hips in the younger group. Kaplan-Meier survivorship analysis, with radiographic progression of osteoarthritis as the end point, predicted a ten-year survival rate of 70.0% in the older group and 93.7% in the younger group; this difference was not significant, with the numbers available (p = 0.062, log-rank test). CONCLUSIONS: Our results indicate that rotational acetabular osteotomy for elderly patients can prevent progression of osteoarthritis (as indicated by a survival rate of 70% at ten years) and that in selected cases it is worthwhile at least as a temporizing operation.

Rotational acetabular osteotomy for hip dysplasia: spontaneous medial enlargement of the acetabulum.

We followed 56 patients (63 joints) who had undergone rotational acetabular osteotomy (RAOs) between 1987 and 1993, mean 7 (5-12) years. The Merle d'Aubigné score increased by 15 points or more in 59 and decreased in 4 hips. The arthrosis progressed in 5 joints. In about 2/3 of the cases, we observed some medial and/or lateral expansion of the subchondral bone in the acetabulum 3 years postoperatively, suggesting enlargement of the load-bearing area.