Bone-Anchored Prosthesis

BAPs can improve physical function, prosthetic use, and quality of life by avoiding socket-related pain and skin problems. The OPRA system has been in use since the 1990s and is considered a stable, well-fixated implant system. The Axor II safety device is designed to protect the osseointegrated implant parts when excessive forces act on the external prosthesis. The OPRA system is designed so that excessive loading preferentially damages exchangeable abutment components rather than the osseointegrated fixture itself. The OPRA procedure requires two surgical stages: Stage 1 places the fixture, and Stage 2 inserts the abutment 3–6 months later after bone integration. Earlier OPRA research found that 29% of patients required abutment or abutment screw exchange within 5 years due to implant fractures. Prospective studies of transfemoral OPRA implants reported only 17% revision-free survival for mechanical complications after 10 years. Bone-anchored prostheses are transcutaneous osseointegrated implant systems designed for amputees who have major functional problems with conventional socket prostheses.