Outcome of rotational acetabular osteotomy for early hip osteoarthritis secondary to dysplasia related to femoral head shape: 49 hips followed for 10–17 years

Figures & data

Figure 1. Roundness index: A/B × 100%

Figure 2. Radiographic parameters. A: CE angle; B: ace-tabular roof angle. Acetabular head index (AHI) = a/b × 100.

Figure 3. Roundness index of the femoral head and radiological results (good versus poor: p < 0.001).

Comparison of radiographic parameters between the "good" and "poor" groups (unaltered osteoarthritic stage and progressed osteoarthritic stage, respectively)

Radiographic	Good (n = 38)			Poor (n = 9)
parameter	Preop.	Postop.	Follow-up	Preop.	Postop.	Follow-up
Center-edge angle, mean (SD)	2.3(9.1)	43 (13)^a	46(14)	0.89(14)	38 (10)^a	49(12)
range	-17–18	22–75	23–75	-18–18	20–55	37–67
Acetabular head index, mean (SD)	55(10)	98(13)^a	99(16)	53(14)	91 (13)^a	100(14)
range	29–76	83–111	82–116	35–74	83–102	85–130
Acetabular roof angle, mean (SD)	28 (7.8)	-8.2 (11)^a	-7.5(12)	31 (4.6)	-1.1 (12)^a	-0.89(13)
range	10–47	-37–10	-50–15	15–50	-15–19	-25–18

^aPostoperatively vs. preoperatively (within-group comparison): p < 0.001.

Figure 4. Various degrees of deformity of the femoral head and the associated roundness index. As deformation of the femoral head increases, the top of the femoral head moves laterally. The black square shows the top of the femoral head.

Figure 5. A. 34-year-old woman with early-stage osteo-arthritis preoperatively. The hip score was 10 points and the roundness index was 68%. B. 3 months postoperatively. C. 11 years postoperatively: narrowed joint space on the lateral side; late advanced stage coxarthrosis. The hip score was 15 points.