FRI680 Atypical Femoral Fracture In Patients With Hypophosphatasia: A Systematic Review

Disclosure: N. Charoenngam: None. J. Thongpiya: None. P. Yingchoncharoen: None. B. Ponvilawan: None. M.S. Marangoz: None. J. Chenbhanich: None. P. Ungprasert: None. A growing number of case reports and case series have demonstrated that atypical femoral fracture (AFF) can occur in patients with hypophosphatasia (HPP). Due to the lack of summary of the clinical manifestation, risk factors, associated ALPL variants and treatment, we conducted this systematic review with the goal to summarize the characteristics of all reported patients with HPP who sustained AFF. Additionally, we aimed to identify all available evidence to quantify the rate of co-existence between HPP and AFF. Potentially eligible articles were identified from MEDLINE and EMBASE databases from inception to September 2022 using search strategy consisting of terms related to “Hypophosphatasia” and “Atypical femoral fracture”. Eligible articles must report one of the following information: 1.) individual data of patient(s) diagnosed with HPP and AFF, 2.) prevalence of HPP among patients with AFF or 3.) prevalence of AFF among patients of HPP. Characteristics of patients reported in each study were extracted. A total of 148 potentially eligible articles were identified from the databases. After systematic review, 23 articles met the eligibility criteria. A total of 27 patients with AFF and HPP were identified. The mean ± SD age of the reported patients was 53.8 ± 12.7 years and 21 patients (77.8%) were female. Nine patients (33.3%) received antiresorptive medication (bisphosphonate and/or denosumab) and two patients (7.4%) received teriparatide prior to development of AFF. Seven (25.9%) and 17 (63.0%) patients sustained unilateral and bilateral AFF, respectively. Twelve patients (44.4%) had a history of fractures at other sites. Four (14.8%) and six (21.4%) patients received asfotase alfa and teriparatide after sustaining AFF. Two studies that reported the prevalence of AFF among patients with HPP of approximately 10%. One study reported one HPP patient in a cohort of 72 patients with AFF. In summary, based on the limited evidence, AFF occurred in up to 10% of patients with HPP. Based on the 27 case reports, almost two-thirds did not receive antiresorptive treatment, suggesting the HPP itself could potentially be a risk factor for AFF. Presentation: Friday, June 16, 2023