When should new sockets be indicated based on sock ply?

New sockets are typically indicated when the thickness of the sock ply reaches 15-20 ply. This amount of thickness often indicates that the residual limb has experienced enough volume change—either increasing or decreasing—that it is impacting the fit and function of the prosthesis. Sockets need to be adjusted or replaced to ensure optimal comfort and performance, as a proper fit is crucial for effective prosthetic use.

In the context of sock ply, a thinner ply (such as in the 5-10 range) may not necessitate a new socket, as it indicates that the residual limb is still within a manageable size range. Conversely, when the sock ply exceeds 20, it typically suggests that major adjustments have occurred in the limb's size, which may require more than just a new socket or could indicate an excessive volume change that exceeds typical adjustments. Therefore, monitoring sock ply is an important part of prosthetic care, with the 15-20 ply range serving as a key indicator for when action should be taken regarding the socket.