The First FDA Approved Early Feasibility Study of a Novel Percutaneous Bone Anchored Prosthesis for Transfemoral Amputees: A Prospective 1-year Follow-up Cohort Study

Abstract

ObjectiveEvaluate the safety and efficacy of a novel press-fit bone-anchored prosthesis in an FDA approved study. DesignSingle-center, prospective 1-year follow-up cohort study of a percutaneous bone anchored prosthesis. SettingVeterans Health Administration Hospital. ParticipantsTen male Veterans with unilateral transfemoral amputation that occurred at least 6 months prior to enrollment and was not the result of dysvascular disease (N=10). InterventionsAll participants received the novel press-fit Percutaneous Osseointegrated Prosthesis (POP) and a minimum of 10 days supervised rehabilitation therapy. Outcome MeasuresAdverse events and radiographs were collected to assess device safety. Temporal assessments of bone density, stomal skin, prosthetic don/doff, functional ambulation, and patient-reported outcome compared our POP to a socket suspension system. ResultsTen male participants mean age 48.8±12.1 years (range, 32-68 y) with mean time since amputation of 9.4± years (range 1-18 y) completed a two-staged implantation protocol and progressed to ambulation with an assistive device by post-operative day 14. Eight of 10 completed all study procedures. One implant loosened at 5 weeks, requiring removal. A second was removed after periprosthetic fracture from a non-device-related fall at 28 weeks. One patient required oral antibiotics for superficial infection. There were significant (P<.05) increases in bone density in the lumbar spine and adjacent to the distal porous coating with no radiographic evidence of bone resorption. Compared to the socket system, the use of POP significantly (P<.05) reduced prosthetic don and doff times and patient-reported prosthetic problem scores. Significant improvements (P<.05) in mean mobility, global health, and walking test scores were also observed. ConclusionsImprovements in bone density, function, and patient reported outcomes were observed with the POP device when compared to a socket suspension system. This Early Feasibility Study established initial safety and effectiveness of the POP device, supporting expanded investigation as an alternative to socket prostheses.