Journal of Pediatric Orthopaedics - 2026-07-01 - Journal Article
Preliminary Report on Hip Abductor Strength Following Proximal Femoral Varus Osteotomy and Greater Trochanteric Apophysiodesis for Legg-Calve-Perthes Disease.
Carter J, Edwards D, Jo C, Jeans K, Lee J, Kim HKW
Topics
Key Takeaway
Following FVO+GTA for LCPD, clinically significant hip abductor weakness (≥25% side-to-side deficit) occurred in 15% of patients (4/26), and all 4 were in the home exercise-only group versus 0/15 in the outpatient physiotherapy group.
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Summary
This study quantified isokinetic hip abductor strength in 26 patients who underwent unilateral FVO+GTA for LCPD at Waldenström stages 1b–3a, with testing performed at stages 3b–4. Despite significant reductions in NSA and ATD on the operated side, overall abductor strength did not differ significantly between sides (P=0.15). Subgroup analysis revealed that the home exercise group (n=11) had significantly weaker operated-side abduction versus contralateral (P=0.027), while the outpatient physiotherapy group (n=15) showed no deficit (P=0.93), with all 4 patients meeting the ≥25% weakness threshold belonging to the home exercise cohort.
Key Limitation
The non-randomized, retrospective rehabilitation group assignment introduces substantial selection bias, making it impossible to determine whether outpatient physiotherapy caused the strength difference or whether patients with better baseline function or compliance were preferentially referred to it.
Original Abstract
BACKGROUND
Femoral varus osteotomy (FVO) is a common treatment for Legg-Calve-Perthes disease (LCPD). Due to concerns of decreased hip abductor strength, neck-shaft angle (NSA), and articular-trochanteric distance (ATD), concomitant greater trochanteric apophysiodesis (GTA) is often performed. While abductor strength remains a concern, no studies have quantified hip strength following FVO+GTA. The purpose of this study was to objectively quantify hip strength in patients treated with FVO+GTA using isokinetic testing and analyze contributors to abductor weakness.
METHODS
A retrospective review was conducted for 26 patients who underwent unilateral FVO+GTA at Waldenström stages 1b-3a, and hip strength testing in stages 3b-4 using an isokinetic dynamometer. The strength of the operated side was compared with the contralateral side. Clinically significant abductor weakness between the contralateral and operated side was set at ≥25% based on previous data.
RESULTS
The mean age at diagnosis was 7.7±1.2 years (range: 5.9 to 9.6) and the time from surgery to testing was 3.3±1.3 years (range: 1.8 to 6.1). While the operated side showed significant decreases in NSA ( P <0.001) and ATD ( P =0.002) compared with the contralateral side, no significant difference in the abduction strength between sides was observed with a paired t test ( P =0.15). However, when patients were grouped by those who did only home exercises (n=11, 42%) versus outpatient physiotherapy (n=15, 58%), the home exercise group showed significantly weaker abduction strength on the operated side compared with the contralateral side with a paired t test ( P =0.027), whereas the outpatient physiotherapy group was insignificant ( P =0.93). In addition, all 4 patients who had abductor weakness ≥25% on the operated side were in the home exercise group.
CONCLUSIONS
Following FVO+GTA, only 4 out of 26 patients (15%) had clinically significant abductor weakness, all of whom did only home exercises. We recommend outpatient physiotherapy after FVO+GTA to obtain more symmetrical abduction strength.
LEVEL OF EVIDENCE
Level III.