Measurement of center-edge angle in developmental dysplasia of the hip: a comparison of two methods in patients under 20 years of age

137

161

Background The definition of osseous instability in radiographic borderline dysplastic hips is difficult. A reliable radiographic tool that aids decision-makingspecifically, a tool that might be associated with instability-therefore would be very helpful for this group of patients. Questions/purposes (1) To compare a new radiographic measurement, which we call the Femoro-Epiphyseal Acetabular Roof (FEAR) index, with the lateral centeredge angle (LCEA) and acetabular index (AI), with respect to intra-and interobserver reliability; (2) to correlate AI, neck-shaft angle, LCEA, iliocapsularis volume, femoral antetorsion, and FEAR index with the surgical treatment received in stable and unstable borderline dysplastic hips; and (3) to assess whether the FEAR index is associated clinical instability in borderline dysplastic hips. Methods We defined and validated the FEAR index in 10 standardized radiographs of asymptomatic controls using two blinded independent observers. Interrater and intrarater coefficients were calculated, supplemented by Bland-Altman plots. We compared its reliability with LCEA and AI. We performed a case-control study using standardized radiographs of 39 surgically treated symptomatic borderline radiographically dysplastic hips and 20 age-matched controls with asymptomatic hips (a 2:1 ratio), the latter were patients attending our institution for trauma unrelated to their hips but who had standardized pelvic radiographs between January 1, 2016 and March 1, 2016. Patient demographics were assessed using univariate Wilcoxon two-sample tests. There was no difference in mean age (overall: 31.5 ± 11.8 years [95% CI, 27.7-35.4 years]; stable borderline group: mean, 32.1± 13.3 years [95% CI, 25.5-38.7 years]; unstable borderline group: mean, 31.1 ± 10.7 years [95% CI, 26.2-35.9 years]; p = 0.96) among study groups. Treatment received was either a periacetabular osteotomy (if the hip was unstable) or, for patients with femoroacetabular impingement, either an open or arthroscopic femoroacetabular impingement procedure. The association of received treatment categories with the variables AI, neck-shaft angle, LCEA, iliocapsularis volume, femoral antetorsion, and FEAR index were evaluated first using Wilcoxon two-sample tests (two-sided) followed by stepwise multiple logistic regression analysis to identify the potential associated variables in a combined setting. Sensitivity, specificity, and receiver operator curves were calculated. The primary endpoint was the association between the FEAR index and instability, which we defined as migration of the femoral head either already visible on conventional radiographs or recentering of the Each author certifies that he or she, or a member of his or her immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. Results The FEAR index showed excellent intra-and interobserver reliability, ...

“…This superiority may be because of difficulty in defining the edge of the acetabular sourcil as has been alluded to [16].…”

Section: Discussionmentioning

confidence: 99%

Section: Measurement Of the Lcea Of Wibergmentioning

confidence: 99%

The Femoro-Epiphyseal Acetabular Roof (FEAR) Index: A New Measurement Associated With Instability in Borderline Hip Dysplasia?

Wyatt

Weidner

Pflüger

et al. 2017

137

161

“…We evaluated patients radiographically according to Severin's criteria (Table 2) [25]. At the last followup the acetabular roof obliquity angle, the center-edge angle of Wiberg, the Reimers index and the acetabular depth-to-width ratios were also measured as radiographic parameters [7,9,12,16,20].…”

Section: Methodsmentioning

confidence: 99%

“…This was the angle subtended by the line connecting the inferior-most edge of the roof of the acetabulum to the lateral-most edge of the acetabulum with a parallel horizontal line [12]. The center-edge angle of Wiberg is formed by a line parallel to the longitudinal body axis and by the line connecting the center of the femoral head (C) with the edge (E) of the acetabular roof [16]. The width of the femoral head parallel to Hilgenreiner's line is measured as line (b), and the distance (a) from the lateral border of the femoral head to the Ombrédanne-Perkins line.…”

Section: Methodsmentioning

confidence: 99%

How Are Outcomes Affected by Combining the Pemberton and Salter Osteotomies?

Bursalı¹,

Tonbul²

2008

The Pembersal operation combines features of the Pemberton and Salter osteotomies. Results have usually been reported in patients with dysplasia but without frank dislocation. We asked if the following factors influence the outcome of the Pembersal operation in patients with dislocated hips: triradiate cartilage damage causing early closure; the acetabular index improvement; and the age of the patient at time of operation. We assessed triradiate cartilage damage, a modified McKay clinical classification, acetabular index, center-edge angles, Reimers index, acetabular depth-to-width ratios, Severin classification and Tönnis grading of 33 patients (44 hips) have been evaluated in this retrospective study. The mean age at surgery was 5 years (range, 1.5-14 years). The minimum followup was 5 years (mean, 10.5 years; range, 5-17 years). Preoperatively, three (7%) hips were Tönnis Grade 2, 10 (23%) were Grade 3, and 31 (70%) were Grade 4. Eight (18%) hips were Severin Class 1, 32 (73%) Class 2, and four (9%) were Class 3. According to McKay's criteria satisfactory results with a rate of 76% were obtained.

“…Plain radiographs showed a positive crossing sign, a center edge angle of Wiberg [22] of 42°, and no evidence of coxa profunda [6,13,16,17,22]. No loose bodies or bone spurs were seen and there was no evidence of degenerative arthritis.…”

Section: Case Reportmentioning

confidence: 99%

Case Report: Bifid Iliopsoas Tendon Causing Refractory Internal Snapping Hip

Shu

Safran

2011