The Ethnocare Overlay pumps up socket fit without removing the leg. Now it works above the knee too.

Socket volume is not a solved problem. Residual limbs shift throughout the day because of temperature, activity, hydration, fluid retention, and body composition changes over time. The standard response has been prosthetic socks, which work until they don’t, and a socket that fit at 9 am can feel loose and wobbly by early afternoon.

One approach to that problem: an air-based sleeve that sits inside the existing socket and lets users add or release volume on the fly without taking the prosthesis off.

The Ethnocare Overlay is a thin textile sleeve with integrated air cells. It goes over the existing liner, inside the socket. When fit loosens, the user adds air through a small valve; the cells expand into available space, restoring contact and reducing pistoning. When the fit is too snug, the deflation valve releases pressure. Adjustments happen with the prosthesis on.

Clinically, this fits under the umbrella of in-socket volume management, which Mara covered in some detail when adjustable sockets come up at a prosthetist appointment. The Overlay is not itself an adjustable socket. It is a sleeve that lives inside whatever socket you already have and adjusts the effective internal volume.

Now available for transfemoral users

The transtibial version of the Overlay has been around for a while. The news from Ethnocare is that the Overlay TF, designed for above-knee prostheses, is now available.

Above-knee socket fitting has different constraints than below-knee. Transfemoral sockets load the ischium and the femur, and volume management options have historically been more limited at that level. The TF version is sized and configured for transfemoral anatomy specifically, not just a resized version of the TT product.

Suspension compatibility

A volume management tool that requires swapping out a suspension system is a harder ask than one that fits inside what a person already uses. The Overlay is designed to work within existing setups. It is compatible with pin-lock, lanyard, suspension sleeve, cushion liner, seal-in, passive vacuum, and active vacuum systems.

Reimbursement: what the L-5657 code means and what it doesn’t

In the US, the Overlay is recognized under HCPCS code L-5657. That code gives clinicians a specific billing pathway for an adjustable volume management insert.

Having a code is not the same as having coverage. Actual reimbursement still depends on medical necessity documentation, individual payer policies, and the specific insurance plan. Some plans will require prior authorization. If you are interested in pursuing this, the conversation with your prosthetist about whether your insurer covers L-5657 and what documentation they need is the necessary first step.

Access and upcoming sizing

Clinics can order through the major US distributors: SPS, Hanger, Cascade, PEL, and Empire Medical. Prosthetists can also contact Ethnocare directly at clinics@ethnocare.ca for clinical presentations or questions about sizing.

Ethnocare is adding XShort sizes to the transtibial range for users with shorter residual limbs and limited space inside the socket. No specific availability date has been announced.

What this means

If you deal with socket volume fluctuations and have been managing with socks, losing the fight by mid-afternoon, or both, the Overlay is worth bringing up with your prosthetist. It does not require a new socket or a new suspension system. The reimbursement code exists, which matters for whether your insurer will pay for it.

For above-knee users specifically, the new TF version expands a tool that was previously only available to transtibial users. Whether it suits your anatomy, socket configuration, and suspension type is a question for someone who can look at your setup directly.

Mara Riggs covers practical life, gear, work, and travel for Amputee News. Nothing in this article is clinical or fitting advice for any specific reader’s situation. Consult your prosthetist about what options are appropriate for your limb level, socket design, and insurance coverage.