gms | German Medical Science

Objectives: Assess the improvement of proximal femur bone mineral density (BMD) in two prospective clinical studies two years after treatment with a AGN1 hip Local Osteo-enhancement Procedure (LOEP).

Methods: LOEP was evaluated in prospective, single-armed, cohort clinical studies in USA (Copley) and Europe (Confirm). Studies received ethics committee and IRB approvals; all subjects provided written consent. Criteria for both studies included post-menopausal women at high risk of hip fracture with femoral neck T-score less than or equal to -2.5. LOEP was performed by injecting the femoral neck and intertrochanteric areas of the proximal femur with a triphasic, resorbable calcium-based implant (AGN1). 72 osteoporotic subjects/85 hips were treated with LOEP as unilateral or bilateral cases. To date, a sub-set of 26 operated hips in 25 subjects was evaluated with baseline and 2-year BMD data (Copley, 12; Confirm, 14). Copley evaluated the AGN1 implant resorption and replacement with bone utilizing sequential radiographs and computerized tomography (CT) scans at 12 weeks, 24 weeks and 5-7 years. The Confirm study is ongoing and will collect follow-up data to 5 years.

Result: Subjects were aged 70±10 with a baseline mean femoral neck T-Score of -3.0±0.5 (N=26). The mean pre-operative FRAX score for 10-year probability of hip fracture was 11±10% (N=26). Skin-to skin surgical time was 16±4 minutes (N=14). The mean volume of injection was 17.6±2.6 cc (N=26). CT and radiographs demonstrated complete AGN1 resorption and replacement with bone (N=26). Baseline femoral neck BMD was not statistically different between studies (p=0.085). After 2.1±0.4 years, the mean percent difference in BMD increased by 61%±37% (p<0.001) from baseline (N=26). All patients were weight bearing as tolerated after surgery and returned to activities of daily living in less than one week.