gms | German Medical Science

Objectives: To develop a safe, minimally invasive procedure to deliver a proprietary calcium-based implant to the proximal femur of osteoporotic patients.

Methods: The LOEP technique was initially performed in a study of 12 postmenopausal osteoporotic women and further refined during 3 cadaver sessions. The procedure was carried out on a fracture table with fluoroscopic navigation and performed under sedation. The skin incision site was injected with a local anesthesia and a 1 cm incision was made in the lateral thigh to access the femur. A 5.3 mm cortical entry portal was created on the lateral surface of the femur just distal to the greater trochanter and above the level of the lesser trochanter to enter the osteoporotic proximal femur. To access the implant site through this minimally sized entry portal, while allowing full access to the implant area of the proximal femur, a specially designed debrider was used. Non-structural material in the implant area was loosened with the debrider and then removed with saline irrigation and suction. A 10 inch 8-gauge cannula with a 30° bend was used to inject the implant material into the debrided area under low pressure using fluoroscopic guidance. Once the implant was delivered, the skin incision was closed. In the clinical study, one hip was injected with a proprietary calcium-based implant and the contralateral hip served as the control. Patients were followed for 5-7 years post-treatment. Treated and control hip BMDs were compared at each timepoint using a paired T-test. The US Western Institutional Review Board approved the study; all patients provided written informed consent.

Results and Conclusion: During cadaver training 20 orthopedic surgeons were successfully trained to fill the osteoporotic femoral neck with the implant material using LOEP to provide immediate mechanical support. In the clinical study there were no procedure or device related serious adverse events. The procedure was easily repeatable and all patients' recovery was uneventful. Clinical outcomes included a femoral neck BMD increase in treated vs. contralateral non-treated hips of 68%, 64% and 57% at 1, 2 and 5-7 years, respectively (p<0.001 for all timepoints).

LOEP provides a safe, easily repeatable and minimally invasive technique for local treatment of osteoporosis in the proximal femur. This procedure addresses the local effects of osteoporosis in the proximal femur: the pathology of bone loss with abnormal architecture and reduced density. It also allows the placement of the implant at the site of highest fracture risk. The enhancement provided by this procedure provides immediate and durable advantage for bone at high risk of failure while using a safe, minimally invasive approach.