A transmetatarsal amputation (TMA) is a surgical procedure that removes the front portion of the foot at the level of the metatarsal bones, the long bones that connect the midfoot to the toes. It preserves the heel and the ankle joint, which allows many patients to walk again with the help of specialized footwear. TMAs are one of the most common partial foot amputations and are primarily performed to treat severe infections, gangrene, or non-healing wounds in the forefoot.
Why a TMA Is Performed
The most common reason for a transmetatarsal amputation is tissue damage in the forefoot that cannot be reversed. This typically falls into a few categories: chronic forefoot ulcers that won’t heal, gangrene affecting multiple toes, a combination of both (often complicated by diabetes), or a severe crush injury where the forefoot can’t be reconstructed. Diabetes with nerve damage is the single most frequent underlying condition, because the loss of sensation leads to unnoticed injuries that progress to deep infections or tissue death.
The most important factor surgeons evaluate before recommending a TMA is blood flow to the foot. Without adequate circulation, the surgical wound itself won’t heal, and the patient may need a higher-level amputation later. When blood flow is sufficient, a TMA offers a major advantage: it saves enough of the foot to bear weight, avoiding the greater mobility loss that comes with a below-knee amputation.
What Happens During Surgery
The surgeon makes a curved, fish-mouth-shaped incision across the top of the foot, running from roughly the midshaft of the outermost metatarsal to the midshaft of the innermost one. The cut is positioned just behind the damaged tissue. It extends down to the bone, and blood vessels are sealed as the surgeon works deeper.
Once the metatarsal bones are exposed, they are cut with a saw and the sharp edges are smoothed down. Tendons on both the top and bottom of the foot are detached and trimmed. A flap of tissue from the sole of the foot is then created. This plantar flap is critical because the thick, weight-bearing skin on the sole provides a durable surface to cover the end of the residual foot. The wound is thoroughly irrigated, and the flap is sutured closed over the bone ends.
Healing Rates and the Risk of Further Surgery
A large 2025 study of 268 patients with non-ischemic diabetic foot infections compared TMAs directly to amputations of multiple individual toes. The TMA group healed at a rate of 89.3%, compared to 74.5% for the multiple-toe group. TMAs also led to 55% fewer recurring ulcers and 59% fewer cases where a higher amputation was eventually needed. Only 8.7% of TMA patients required a more proximal amputation afterward, versus 21.3% of those who had multiple toes removed separately.
That said, the overall risk of eventually needing an above-ankle amputation following a TMA is around 30%, particularly in patients with peripheral artery disease. Patients without diabetes but with poor arterial circulation actually face a higher reamputation risk than diabetic patients, likely because their blood supply problems are more severe. Having a prior ray amputation (removal of a toe along with part of its metatarsal) before the TMA also increases the odds of needing further surgery.
How Walking Changes After a TMA
Losing the forefoot changes the mechanics of walking in several significant ways. The most dramatic change is at the ankle. Normally, the ankle generates substantial push-off power during the final phase of a step, using the long lever arm of the forefoot against the ground. After a TMA, that lever arm is gone. Ankle power generation drops to roughly 28% of normal levels, and the ankle’s range of motion during walking falls to about 70% of the unaffected side.
To compensate, the body shifts the workload upward. People who’ve had a TMA rely more heavily on their hip flexor muscles to swing the leg forward, rather than the ankle muscles that would normally propel them. Walking speed decreases noticeably compared to age-matched peers. Pressure distribution also changes: the heel absorbs more force, and the center of pressure during each step stays well behind the end of the residual foot rather than rolling forward to the tips of the toes as it would in an intact foot. These shifts explain why proper footwear is so important for preventing new pressure injuries on the shortened foot.
Footwear and Orthotics After Surgery
The simplest approach after a TMA is packing the empty toe box of a regular shoe with lamb’s wool. Early studies found that many patients managed reasonably well this way, but modern options do much more to protect the foot and restore a more natural gait.
The most effective single modification is a rocker bottom sole, a curved sole with an apex positioned just behind the residual metatarsal ends, angled at about 20 degrees. Research shows this design can reduce peak pressure on the forefoot by up to 50%. The rocker shape allows the shoe to roll forward during a step, partially recreating the push-off motion that the missing forefoot can no longer provide.
A custom-molded total contact insert fits snugly against the entire bottom of the residual foot, spreading pressure evenly rather than concentrating it on a few points. When combined with a custom shoe and rocker bottom sole, these inserts reduce pressure on both the forefoot and heel. Adding a steel shank or carbon fiber plate to the sole of the shoe provides additional rigidity, preventing the shoe from collapsing around the shortened foot and partially restoring the stiff lever arm that the metatarsal bones once provided. Some patients also benefit from an ankle-foot orthosis, a lightweight brace that stabilizes the ankle and helps control the foot’s tendency to drift inward after surgery.
The combination that offers the most support is a custom shoe with a rocker bottom sole, total contact insert, and ankle-foot orthosis. Not every patient needs all of these elements. The right setup depends on activity level, wound healing, and how much the gait has been affected. A prosthetic shoe filler restores the visual appearance of the foot inside a shoe and helps prevent the shoe from folding at the empty toe box.
Why TMA Is Often Preferred Over Higher Amputations
A transmetatarsal amputation preserves the ankle joint, the heel pad, and the ability to stand and walk without a prosthetic limb in the traditional sense. By contrast, a below-knee amputation requires a prosthetic leg, a socket, and significantly more energy to walk. Studies consistently show that the energy cost of walking increases with each higher level of amputation. For patients with diabetes or vascular disease, who often have limited cardiovascular reserve, that energy difference matters enormously for maintaining independence.
A TMA with a prosthetic shoe filler improves ankle power generation from 28% of normal to about 31%, a modest gain. But when combined with proper orthotics and footwear, the improvements in pressure distribution and stability are substantial enough to allow most patients to walk independently, return to daily activities, and avoid the wheelchair dependence that sometimes follows higher amputations.