The critical relationship between accurate fit of a prosthesis and amputee comfort and function constitutes the foundation of prosthetic fitting. Prosthesis alignment affects the way load is transferred to the residual limb through the socket, and this load is critically important for comfort and function. The aim of the study was to assess the value of radiopaque materials in evaluation of stump-socket fit in people with transtibial amputation, and to develop a simple procedure for clinical use in diagnosing skin pressure problems more accurately.

Thirty-two amputees (herein: ‘participants’) had one or more cutaneous lesion in the stump, and another 26 amputees (control group) had no lesion in the stump after training with their prosthesis. Radiopaque metallic markers were attached to weight-bearing points in the outer surface of the internal socket. Full weight-bearing X-rays were made in the antero-posterior and lateral projections.

In the antero-posterior view, the weight-bearing points of the stump in 78.1% of the participants did not correspond to radiopaque metallic markers placed over the patellar tendon and the tibial tuberosity points in the socket. In the control group, there was non-adaptation in only 42.3% between the up-mentioned anatomical and the metallic (Chi², P<0.007). In the lateral view X-rays, the weight-bearing points of the stump in 65.6% of the participants did not correspond to radiopaque metallic markers placed over the patellar tendon and over the tibial tuberosity points in the socket. In the control group, there was non-adaptation in only 23.1% between the up-mentioned anatomical and the metallic (Chi², P<0.002).

The conflict between prosthesis and residual limb is the cause of skin disruption in the stump and can be successfully treated by prosthetic socket modification. X-rays should be done to identify if there are discrepancies between the stump and the socket.