Technical Overview of Osseointegrated Transfemoral Prostheses: Orthopedic Surgery and Implant Design Centered

Abstract

Bone-anchored prostheses represent a promising solution to numerous medical complications associated with conventional socket-suspended prostheses. The following technical overview was constructed for engineers and orthopedic surgeons interested in osseointegrated implants for transfemoral prosthesis-residuum interfacing. Existing osseointegrated implants comprise different biomaterial compositions (i.e., titanium alloy versus cobalt-chromium-molybdenum alloy) and mechanical designs (i.e., screw-fixated versus press-fixated devices). Perioperative systems of osseointegration surgery include preoperative assessments (i.e., alongside inclusion and exclusion criteria), intraoperative procedures, and postoperative rehabilitation (i.e., static loading and dynamic gait rehabilitation). The intraoperative procedures involve transecting and reorganizing the residual musculature, embedding the implant into the femoral intramedullary cavity, and coupling the osseointegrated implant to an external prosthesis. Postoperative clinical evaluations have demonstrated significant biomechanical, psychological, and physiological improvements in patients using bone-anchored prostheses compared to conventional socket-suspended prostheses. Nevertheless, bacterial infections surrounding the skin-implant bio-interface, often resulting from Staphylococcus aureus or other coagulase-negative staphylococci, remain a relatively frequent medical complication, which can culminate in periprosthetic osteomyelitis and/or implant extraction. The technical overview concludes with discussing the recent Food and Drug Administration humanitarian use device designations, financial analyses between bone-anchored prostheses and socket-suspended prostheses, and applications of vibrotactile osseoperception for augmenting walking and balance feedback control.

Micromotion and Push‐Out Evaluation of an Additive Manufactured Implant for Above‐the‐Knee Amputees

“…These procedures do not have the same socket‐related soft tissue issues, facilitate quick attachment of the amputee's prosthesis, transfer load directly to the residual femur, and enable osseoperception whereby the amputee can discern the type of surface they are walking on . Downsides to direct skeletal attachment include a risk of superficial and deep infection through the skin opening, a risk of femoral fractures, implant extraction, high proximal revision, and potential bone resorption due to stress shielding . Despite the variety of devices, it appears that many surgeons remain unhappy with the concept of a permanent percutaneous implant.…”

“…6 Downsides to direct skeletal attachment include a risk of superficial and deep infection through the skin opening, a risk of femoral fractures, implant extraction, high proximal revision, and potential bone resorption due to stress shielding. [13][14][15][16] Despite the variety of devices, it appears that many surgeons remain unhappy with the concept of a permanent percutaneous implant. Subcutaneous implants have been developed: in the 1960s Swanson et al 17 developed a mushroom-shaped silicone implant in an attempt to improve end bearing.…”

Simulation of Stand-to-Sit Biomechanics for Design of Lower-Limb Exoskeletons and Prostheses with Energy Regeneration

“…Over 12 million individuals in the United States alone have mobility impairments resulting from stroke, spinal cord injury, and other neuromusculoskeletal conditions [1]. There are approximately 2 million Americans with limb amputations [2]. These numbers are expected to significantly increase with the emergent aging population and growing incidences of cancer and diabetes [1][2][3].…”

“…There are approximately 2 million Americans with limb amputations [2]. These numbers are expected to significantly increase with the emergent aging population and growing incidences of cancer and diabetes [1][2][3]. Robotic lower-limb prostheses and exoskeletons can enable geriatric and rehabilitation patients to perform common movements (e.g., sit-to-stand) that necessitate net positive mechanical power by mimicking their amputated or unimpaired biological muscle actuators [4][5][6][7][8][9].…”

“…Consequently, regenerating energy could 1) benefit rehabilitation patients in developing countries without accessible electricity for battery recharging [30][31], and 2) support the development of more sophisticated control technologies (e.g., machine vision and deep learning [32]) that have traditionally required significant computing power. Relating to socket-suspended lower-limb prostheses, minimizing onboard battery weight via energy regeneration could reduce musculoskeletal pain occurrences associated with excessive tugging on the human-prosthesis interface [2].…”