1,161
Views
20
CrossRef citations to date
0
Altmetric
Hip

Cam deformity and hip degeneration are common after fixation of a slipped capital femoral epiphysis

, , , , , & show all
Pages 585-591 | Received 10 Mar 2013, Accepted 19 Jun 2014, Published online: 01 Sep 2014
 

Abstract

Background and purpose — Slipped capital femoral epiphysis is thought to result in cam deformity and femoroacetabular impingement. We examined: (1) cam-type deformity, (2) labral degeneration, chondrolabral damage, and osteoarthritic development, and (3) the clinical and patient-reported outcome after fixation of slipped capital femoral epiphysis (SCFE).

Methods — We identified 28 patients who were treated with fixation of SCFE from 1991 to 1998. 17 patients with 24 affected hips were willing to participate and were evaluated 10–17 years postoperatively. Median age at surgery was 12 (10–14) years. Clinical examination, WOMAC, SF-36 measuring physical and mental function, a structured interview, radiography, and MRI examination were conducted at follow-up.

Results — Median preoperative Southwick angle was 22o (IQR: 12–27). Follow-up radiographs showed cam deformity in 14 of the 24 affected hips and a Tönnis grade > 1 in 1 affected hip. MRI showed pathological alpha angles in 15 affected hips, labral degeneration in 13, and chondrolabral damage in 4. Median SF-36 physical score was 54 (IQR: 49–56) and median mental score was 56 (IQR: 54–58). These scores were comparable to those of a Danish population-based cohort of similar age and sex distribution.

Median WOMAC score was 100 (IQR: 84–100).

Interpretation — In 17 patients (24 affected hips), we found signs of cam deformity in 18 hips and early stages of joint degeneration in 10 hips. Our observations support the emerging consensus that SCFE is a precursor of cam deformity, FAI, and joint degeneration. Neither clinical examination nor SF-36 or WOMAC scores indicated physical compromise.

Study idea and design: KG, KS, and AT. Collection of data: JK, KG, EM, JG, and AT. Analysis and/or interpretation of data: all authors. Writing of draft manuscript: JK, AT, and TK. Editing and approval of manuscript: all authors.

We thank physicist Peter Magnusson for development of the unique Dess 3-D sequence used in this study. We also thank the surgeons at Aarhus University Hospital and Hvidovre University Hospital for their work with this patient group over the years.

No competing interests declared.