# Surgical technique of a transcutaneous osseointegration prosthesis system (TOPS) for transtibial amputees

## TL;DR

This paper describes a surgical method for a bone-anchored prosthetic system that improves mobility and quality of life for below-knee amputees.

## Contribution

The paper introduces a surgical technique for transcutaneous osseointegration prostheses as an alternative to traditional socket prostheses.

## Key findings

- TOPS improves energy transfer and mechanical alignment compared to socket prostheses.
- Implant complications like infection or loosening may require hardware removal.
- Approximately half of transtibial amputees struggle with socket prostheses due to fit and comfort issues.

## Abstract

Transcutaneous osseointegration prosthetic systems (TOPS) are intended to provide stable skeletal attachment for artificial limbs after extremity amputation and is an alternative for socket attachment. TOPS for individuals with limb amputation using osseointegration implants (OI) has proven to consistently and significantly improve quality of life and mobility for the vast majority of amputees, previously using a socket prosthesis also experiencing socket-related problems. As with any implant, complications such as infection, aseptic loosening, or implant fracture can occur, which may necessitate hardware removal. Approximately half of patients who undergo a below-knee amputation are able to utilize an artificial leg acceptably well with a socket-suspended prosthesis. However, the other half of patients experience limitations resulting in reduced prosthesis use, mobility, and quality of life. Limb-to-prosthesis energy transfer is poor because of the so-called “pseudojoint” (i.e., the soft tissue interface), and gross mechanical malalignment is common. Furthermore, transtibial amputees may experience irritation from pistoning and suction at the residual limb–socket interface. These issues result in skin problems and difficulties with socket fit because of fluctuation in the size of the residual limb size, resulting in a decrease in overall satisfaction and confidence in mobility. A bone-anchored implant creates a direct skeletal connection between the residual limb and artificial leg, in which energy transfer is optimal and mechanical alignment is significantly improved.