Transdermal Compress IDE Study

Inclusion Criteria

• Participant must be able to understand the investigational nature of this study and has reviewed and provided written, informed consent prior to any study-specific procedures.
• Participant is a skeletally mature male or female and is 18 - 60 years of age at screening. Participants \< 22 years of age require radiographic confirmation of skeletal maturity and must have failed the use of conventional prosthesis.
• Participant has an estimated BMI of ≥ 18.5 and ≤ 40 kg/m2 and weight ≤ 245 lbs without prosthesis.
• Participant has unilateral or bilateral transfemoral limb loss without bone or vascular disease.
• Participant has problems with conventional prostheses or is not able to use a prosthesis at all or is anticipated to experience problems with a socket prosthesis in the investigator's judgment.
• Participant has adequate bone stock to support the implanted device
• Participant does not have any cortical defect located between the expected location of the anchor plug and spindle/bone interface.
• Participant has the willingness, ability, and commitment to participate in baseline and follow-up evaluations for the full length of the study including the prescribed rehabilitation program.

Exclusion Criteria

• Female participants who are pregnant, nursing, or have a planned pregnancy during the first 12 months post-surgical implantation.
• Participant had a prior osseointegrated device implanted in the lower limb planned for the study device.
• Participant has a history of systemic or localized infection at the residual limb site within 6 months prior to Study Day 1.
• Participant has any distant foci of infections.
• Participant has a history of sepsis within 6 months prior to Study Day 1.
• Participant's length of the residual femur cannot accommodate the intramedullary portion of the Transdermal Compress device.
• Participant has a femoral deformity that in the opinion of the treating surgeon results in an inability to properly insert the Transdermal Compress implant system, and/or results in alignment that is biomechanically unsound.
• Participant does not have an adequate myofascial flap to allow for circumferential contact with the implanted device.
• Participant has evidence of or history of severe peripheral vascular disease or insufficiency, muscular atrophy, neuromuscular disease, or diabetes mellitus (Type I or Type II).
• Participant has evidence of or a documented history of osteomyelitis (excluding the history of osteomyelitis distal to amputation), systemic osteoporosis, or osteomalacia.
• Participants with identified risk factors for osteoporosis must have a reported T-score > -2.5 within 6 months prior to Study Day 1.
• Participant has evidence of or a documented history of severe metabolic disorders that may impair bone formation.
• Participant has a history of systemically administered corticosteroids or immunosuppressive or immunomodulatory therapy or chemotherapy drugs.
• Participant has known drug or alcohol dependence currently or within the last year.
• Participant is a smoker, nicotine, or tobacco user in any form or who has used nicotine or tobacco-containing products within the past 6 months prior to Study Day 1.
• Participant has any other condition, which in the opinion of the Investigator, precludes the participant's participation in the study or the participant is unlikely to comply with the protocol-defined