HIP JOINT OSTEOARTHRITIS IN LEGG-CALVÉ-PERTHES DISEASE: A LONG-TIME FOLLOW-UP CASE-CONTROL STUDY

Abstract

Introduction: The purposes of this study are to investigate the inter-relationship between Stulberg class and radiographic hip osteoarthritis (OA) in patients with Legg-Calvé-Perthes disease (LCP) and to determine whether LCP patients develop hip OA more often than sex- and age-matched individuals.

Material and Methods: 167 LCP patients presented to our institution from 1941 to 1962. All patients were treated conservatively by a Thomas splint. Retrospectively medical records and radiographs were retrieved.

At follow-up weight-bearing AP pelvis radiographs were obtained. OA was present when the minimum joint space width was < 2.0 mm. Radiographs of sex- and age-matched controls were obtained from The Copenhagen City Heart Study.

The following criteria for exclusion were applied:

1. insufficient or missing radiographs

2. patients who refused to participate,

3. emigrated persons,

4. persons lost to follow-up,

5. patients with previous surgery to pelvis or lower limbs and

6. dead persons.

52 patients (55 hips) were enrolled in the study and 115 patients (136 hips) were excluded. Mean age for men at follow-up was 53 years and for women 55 years.

Results: In the LCP group four hips of 50 hips had OA compared to one hip of 107 hips in the control group. One patient out of 41 in Stulberg class I/II had OA compared to three out of nine in Stulberg class III/IV/V.

Conclusion: LCP patients have a significant higher risk of having hip OA compared to a sex- and age-matched control group, p=0.04 [OR=8.5 (CI=0.8–428.8)]. Patients in Stulberg class III, IV or V have a significantly increases risk of hip OA compared to patients in Stulberg class I or II, p=0.03 [OR=13.7 (CI 1.9–97.1)].