Bone Abstracts

Background: Current extension in the usage of growth hormone therapy (GHT) has increased the prevalence of bone complications. Legg Calvé Perthes disease (LCPD) is characterized by idiopathic avascular necrosis of the proximal femoral epiphysis. More frequently in boys between 4 and 8 years, LCPD is of unknown ethology. An increased incidence has been stated in case of GH deficiency. There is increasing data that children with LCPD may have a more widespread skeletal disorder involving short stature, disproportionate growth retardation and delayed bone age.

Case reports: Case 1: 8 years 8 months old boy, addressed for growth retardation. At 8 years 3 month he was diagnosed with LCPD of the right hip. He was small for his age (115 cm, −3.2 S.D.), underweight, with small and triangular facies, flat feet, lower limb length asymmetry (right<left with 2 cm), bilateral genu recurvatum, clinodactyly of the 5^th finger. He had delayed bone age of ~7 years. Somatotropin axis investigations revealed low IGF-1 (48 ng/ml, N: 64–345). GHT was considered contraindicated due to the higher risk of contralateral LCPD. Case 2: 7 years old male, presented in January 2014 height deficit (97 cm, −2.54 S.D.) and significantly delayed bone age (2 years) and GHT was started: Somatropin 0.23 mg/kg per week, with good evolution (height velocity >0.6 cm/month). In August 2016, his growth velocity decreased to 0.35 cm/month and he complained of pain in his left hip, increasing with activity. Limping and a deficit in internal rotation of the left hip were noted. Radiography of the lower extremity was conducted and left LCPD was diagnosed. GHT was interrupted.

Conclusion: Orthopaedic complications associated with GHT are rare, but severe. Whatever the causal association, the presence of LCPD imposes caution in children with GHT. To our knowledge there have been only a few reported cases of LCPD in children with GHT. Before beginning GHT, it is essential to take into account all the risk factors of the individual patient. Close monitoring with clinical and radiographic check-up is required to allow early diagnosis and treatment of these complications, but no published guidelines exist to date.

Disclosure: The authors declared no competing interests.