Osseointegrated Transcutaneous Device for Amputees: A Pilot Large Animal Model

Abstract

Traditional above-the-knee amputation prosthetics utilize a stump-socket interface that is well-known for skin/socket problems, sitting difficulty, disuse osteopenia, and increased work of ambulation. As a result, we evaluated a novel osseointegrated transcutaneous implant in a large animal. The implant was designed to promote osseointegration at the bone-implant interface and minimize complications. As proof of concept, four Dorset sheep underwent a two-stage surgery for forelimb placement of an osseointegrated transcutaneous implant utilizing Compress® technology (Biomet, Inc., Warsaw, IN). Two sheep received a long anchor plug (90 mm long x 9 mm in diameter) and two received a short anchor plug (46 mm long x 9 mm in diameter). Sixteen weeks after the initial surgery, the operative limbs, along with the attached implant, underwent radiographic and histological analysis for osseointegration. Periprosthetic fractures occurred in the two animals that received the longer internal prosthesis; one healed with splinting and the other animal underwent a second surgical procedure to advance the amputation site more proximal. No fractures occurred in the shorter internal prosthesis group. There was no histological evidence of infection and none of the transcutaneous adapters failed. Bone-implant osseointegration was demonstrated in two of three limbs that underwent histological analysis. This unique implant demonstrated osseointegration without transcutaneous adapter failure, all while displaying minimal infection risk from the outside environment. Although it involved short-term follow-up in a limited number of animals, this pilot study provides a platform for further investigation into the valid concept of using Compress® technology as an endo-exo device.

Comparative finite element analysis of an osseointegration system in transradial amputation: a proposal of a new design for osseointegration

“…Patients with amputated limbs have traditionally relied on a stump-socket interface for prosthetic attachment [7]. This type of prosthetic design is associated with several problems, such as skin changes, increased energy expenditure during ambulation, and disuse osteopenia [17][18][19].…”

“…Currently, only a few osseointegrated transcutaneous prosthetic systems (such as OPRA system [Integrum AB, Mölndal, Sweden] and ITAP system [Stanmore Medical Group, Stevenage, UK]) for use in humans exist but none are approved for general use in the United States [7,8]. Conventional osseointegration systems have been applied to transhumeral (OPRA system and ITAP system) and transfemoral amputations (OPRA system and ISP Endo/Exo prosthesis [ESKA Implants AG, Lubeck, Germany]).…”

Comparative Finite Element Analysis of Osseointegration System in Trans-Radial Amputation: A Proposal of New Design

“…Patients with amputated limbs have traditionally relied on a stump-socket interface for prosthetic attachment. 7 This type of prosthetic design is associated with several problems, such as skin changes, increased energy expenditure during ambulation, and disuse osteopenia. [12][13][14] Several types of osseointegration systems have been developed to overcome these problems and are currently clinically available; however, these osseointegration systems also encountered several problems of their own, which are infection, periprosthetic bone fracture, bone loss due to stress shielding, and implant failure.…”

“…Currently, only a few osseointegrated transcutaneous prosthetic systems(such as OPRA system, Integrum AB from Mölndal, Sweden and ITAP from Stanmore Medical Group, Stevenage, England) for use in humans exist but none are approved for general use in the United States. 7,8 Conventional osseointegration systems have been applied to trans-humeral(OPRA system and ITAP system) and transfemoral amputations(OPRA system and ISP Endo/Exo prosthesis from ESKA Implants AG, Lubeck, Germany). However, the application of these systems in patients requiring trans-radial amputations have limitations due to the small diameter of the radius and ulna.…”