Comparative study between patellar-tendon-bearing and pressure cast prosthetic sockets

Area of Science:

• Prosthetics and Orthotics
• Biomechanics
• Biomedical Engineering

Background:

• Socket design is crucial for comfort and function in lower-limb amputees.
• Traditional patellar-tendon-bearing (PTB) sockets have limitations in pressure distribution.
• Novel socket systems aim to improve residual limb-socket interface pressure.

Purpose of the Study:

• To compare residual limb and socket interface pressure distribution between the pressure cast (PCast) socket and the patellar-tendon-bearing (PTB) socket.
• To analyze pressure profiles during standing and walking in unilateral amputees fitted with both socket types.

Main Methods:

• Four male unilateral amputees were fitted with both PCast and PTB sockets.
• A custom strain-gauge-type pressure transducer was used to record pressure.
• Pressure data was collected during static standing and dynamic walking activities.

Main Results:

• Pressure distribution varied between subjects and socket types.
• Some subjects showed similar anterior-posterior and medial-lateral pressure profiles for both sockets, particularly during push-off.
• Other subjects experienced high distal pressure in the PCast socket or proximal pressure concentration in the PTB socket.

Conclusions:

• The PCast and PTB sockets elicit different pressure distribution patterns in the residual limb-socket interface.
• Individual variability in pressure profiles highlights the need for personalized prosthetic fitting.
• Further research is warranted to optimize socket design for improved amputee outcomes.