Table 5.
Selected literature about the acetabular version in hips of children with Legg–Calvé–Perthes disease (LCPD)
| Author (year) | Study setup | Number of patients (hips) | Mean age and follow-up (years) | Results |
|---|---|---|---|---|
|
Sankar and Flynn [17] (2008) |
Evaluation of version angle on axial CT or MRI slices in skeletally immature patients. Follow-up past skeletal maturity in 36% of patients with evaluation of cross-over sign on radiographs | 44 (53) | 7 (2–12) n.a. | No difference in acetabular version on axial slices between LCPD (average version of 15°, range -5°–24°) compared to contralateral hip without LCPD. Following skeletal maturity, 31% of hips with LCPD showed a positive cross-over sign. Herring lateral pillar classification [7] (hips in Group C with > 50% loss of height) was predictive for acetabular retroversion |
|
Larson et al. [12] (2011) |
Acetabular retroversion assessed on earliest radiograph available using ischial spine sign. Comparison to control group including 25 patients and 50 hips (trauma cases) | 47 (49) | 7 (4–12) n.a | Positive ischial spine sign in 90% of LCPD with open triradiate physis, 75% in LCPD with closed physis, 64% on contralateral side of unilateral LCPD and 32% in control group. No predictive factors |
|
Yoshida et al. [26] (2016) |
Evaluation of version angle on axial MRI at mean age of 7 (range 4–11) years and after a mean follow-up of 8 (3–14) years | 25 (25) | 7 (4–11) 8 (3–14) | No difference in anteversion for hips with LCPD between initial and follow-up status. At follow-up, hips with a round femoral head and LCPD (Stulberg [18] class I and II) were more retroverted compared to the contralateral hip. In hips with LCPD and an ovoid or flat head (Stulberg classification [18] class III and IV) no difference existed compared to the contralateral side at follow-up. No predictive factors |
| Liao et al. [13] (2021) | Acetabular version angle assessed on axial views of CT scans in 33 male and 7 female patients with unilateral LCPD. 95% of hips in Waldenström stage I or II | 40 (40) | 8 ± 2 n.a | Acetabular anteversion angle was minimally decreased (resembling more retroversion) on the affected side (10.6° ± 8.1°–12.5°) compared to the unaffected side (12.0° ± 9.0° – 13.3°; p = 0.002) |
| Current study | Repeated evaluation of acetabular version in skeletally immature and mature LCPD patients (Waldenström [24] stages I–IV) using pelvic width index, ilioischial angle and obturator index | 51 (55) | 6 (2–13) 7 (2–23) | Decreasing pelvic width and obturator indices and increasing ilioischial angle in the fragmentation and early bon formation stages (Waldenström [24] stages II and III) all indicating acetabular retroversion. Retroversion was associated with younger age, non-dysplastic shape a collapse of the lateral pillar in fragmentation stage |
n.a. not applicable