The Effect of Denosumab on Periprosthetic Bone Mineral Density in Six Transfemoral Amputees Treated With Osseointegrated Implants: The Observations From a Terminated Randomized Controlled Trial

Femur amputated patients often suffer from several problems with conventional socket prosthesis. Some experience changes in gait, discomfort when sitting, altered skin conditions (infection, irritation, rashes, sweat), phantom pain or lack of stabilization between the prosthesis and the residual limb. Many have a low score on "health-related quality of life" questionnaires (HRQL).

Some femur amputated patients may be a candidate to osseointegrated prosthesis. Osseointegrated prosthesis is an implant, where the fixture is inserted into the femur canal and an abutment screw, on which the leg-prostheses is inserted, protrudes the skin. By this procedure the patient have a high score on HRQL and experience fewer problems. They have improved gait, reduced discomfort when sitting, increased prosthetic use, and experience fewer skin and pain problems.

Femur amputee patients formerly mobilized on socket prosthesis have a reduced bone mineral density in the affected femur and pelvis.

The Phd-theses compromise of three studies. The aim of the first study is to follow patients with oosseointegrated prosthesis before and after surgery with DXA-scans to monitor the BMD. In the second study patients will be randomised to receive medical treatment with an RANKL-inhibitor, approved for treatment of osteoporosis, and monitored with DXA, microdialysis and radiostereometry. Depending on the DXA-results patients in the third study may receive fast track rehabilitation.

The hypothesis is that patients with osseointegrated prosthesis will have an increased BMD after surgery, 2 years follow up. Patients receiving RANKL inhibitor will have increased BMD, stability of the prosthesis, and some receive fast-track rehabilitation due to high BMD.