Effects of Growth Hormone Therapy in Children With Growth Hormone Deficiency and Legg-Calvé-Perthes Disease.

Background: Legg-Calvé-Perthes disease (LCPD) is a pediatric hip disorder characterized by idiopathic avascular necrosis of the femoral head. Although its etiology remains unclear, frequent observations of short stature and delayed skeletal maturation have suggested disturbance of systemic growth regulation, particularly involving the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis. This study evaluates the impact of GH deficiency (GHD) and timing of GH therapy (GHT) on radiographic progression and femoral head morphology in LCPD.

Methods: We conducted a retrospective review of 10 patients (11 hips) with GHD and LCPD treated at a single institution. Patients were stratified into 2 cohorts: group A (n=5), diagnosed with GHD and initiated on GHT before LCPD onset, and group B (n=5, 6 hips), diagnosed and treated during LCPD. Each case was matched 1:2 to controls without GHD based on sex, age at diagnosis, stage, and treatment. Radiographic staging and outcomes were assessed using Waldenström and Stulberg classifications. Growth parameters and treatment-related complications were also recorded.

Results: Group A exhibited disease stage duration and femoral head outcomes similar to matched controls. In contrast, group B experienced significantly prolonged fragmentation (1.8 vs. 0.8 y of matched controls, P=0.008) and reossification stages (5.8 vs. 3.9 y, P=0.006), along with worse femoral head sphericity (Stulberg I/II in 0% vs. 67%, P=0.013). Notably, all group B patients had growth deceleration (growth velocity <5 cm/y) before GHD diagnosis. GHT was well tolerated in all cases, with no orthopaedic complications.

Conclusions: GHD diagnosed and treated during LCPD was associated with prolonged fragmentation and reossification stages and poorer femoral head morphology. In contrast, patients with GHD treated before LCPD onset demonstrated outcomes similar to matched controls. These findings underscore the potential relevance of the GH/IGF-1 axis in LCPD. Orthopaedic clinicians should maintain vigilance for endocrinopathies in LCPD patients with growth deceleration (growth velocity <5 cm/y) and delayed bone age, as early endocrine referral and treatment may improve outcomes.

Level of evidence: Level III.