Teriparatide Treatment of Subchondral Insufficiency Fractures of the Femoral Head: Case Series

Introduction: Subchondral insufficiency fractures (SIF) of the femoral head reflect a rare clinical entity. The failure rate of conservative treatment is up to 50% and requires total hip replacement as salvage procedure. Teriparatide (Forteo) is an FDA approved drug to enhance bone healing and low bone density. This is the first published data of Forteo treatment for SIF.

Methods: We retrospectively reviewed the charts of all patients diagnosed with femoral head SIF who were treated with Forteo from June 2008 to February 2017. All patients with avascular necrosis, primary osteoarthritis and chronic steroid use were excluded. Serial radiographic and clinical variables were evaluated.

Results: 9 patients (4 female) were identified. Median age at diagnosis was 45 years old. Median BMI was 24, and antero-superior (n=5) location was most common. 7 patients had low bone density of the femoral neck (T/Z score <-2). Median follow up time was 14 months. Median treatment time was 7 months; 1 patient stopped after 2 months due to repeated hypercalcemia. Four patients presented with mild-moderate collapse of the femoral head. One patient progressed to total hip replacement (THR) 134 days from beginning of treatment. Bone marrow edema extending to the femoral neck and hip joint effusion decreased significantly from baseline (n=8 and 7, accordingly) to 100 days post treatment (n=1 and 1, accordingly; all p values=0.03). Ambulation improved with only 1 patient ambulating without aids at baseline and all at median of 267 days from start of treatment (p=0.03). In all patients pain dramatically improved or resolved at median of 267 days from start of treatment.

Conclusion: With almost complete resolution of clinical symptoms and radio graphical changes, and only one patient requiring THR; Forteo should be considered as a medical treatment for SIF. Larger prospective studies are required to better evaluate its utility.