A transmetatarsal amputation is a surgical procedure that removes a portion of the foot. It addresses specific medical conditions that compromise the health and function of the forefoot. This type of amputation aims to remove diseased or damaged tissue while preserving as much of the remaining foot as possible. The procedure is designed to improve a patient’s health by preventing the spread of disease or alleviating persistent pain.
Understanding the Procedure
A transmetatarsal amputation precisely removes the forefoot at the level of the metatarsal bones. These five long bones are in the midfoot, positioned between the ankle (tarsal bones) and the toes (phalanges). They are numbered one to five, starting from the big toe side. The goal is to create a functional, weight-bearing residual limb.
The procedure eliminates non-viable tissue while retaining enough healthy foot structure for continued mobility. Surgeons strive to maintain a significant portion of the foot, aiming for a stable, shoeable stump that enables ambulation. This approach differentiates it from more extensive amputations, as it allows for potential weight-bearing on the remaining foot.
Reasons for the Procedure
Transmetatarsal amputations are often necessary due to conditions severely compromising the forefoot’s viability. A common indication is severe infection, particularly in individuals with diabetes. Diabetic foot ulcers, open sores often on the bottom of the foot, are the leading cause of non-traumatic lower extremity amputations. These ulcers can progress to deep infections that may extend to the bone, making amputation necessary to prevent further spread.
Peripheral artery disease (PAD) is another frequent cause, where narrowed or blocked arteries restrict blood flow to the extremities, especially the legs and feet. This poor circulation can lead to tissue death, known as gangrene, or chronic non-healing ulcers. When conservative treatments fail to improve blood flow or heal these severe tissue issues, a transmetatarsal amputation removes the dead or diseased tissue. Significant trauma to the forefoot resulting in irreparable damage can also necessitate this procedure to prevent complications and facilitate healing.
Surgical Process and Immediate Recovery
A transmetatarsal amputation is typically performed under general or regional anesthesia, depending on the patient’s health status and the surgeon’s assessment. Regional anesthesia, such as a spinal or peripheral nerve block, can be a suitable option and may lead to fewer postoperative complications. The surgical process begins with carefully planned incisions, often a curved or “fish-mouth” shape, made on the top and bottom of the foot to access the metatarsal bones. The surgeon removes diseased or damaged tissue, cutting through the metatarsal bones with a saw. The bony ends are then rounded to create a smoother, more functional residual limb, and non-viable tendons are removed before the wound is thoroughly cleaned.
After removing the affected portion, the remaining skin and tissue flaps are brought together to cover the exposed bone, forming a closed stump. If severe infection is present, the wound might be left open and packed with bandages for drainage and healing. Following surgery, patients typically remain in the hospital for a few days for monitoring and initial pain management. Pain medication is prescribed to control discomfort, and nurses provide instruction on wound care, including dressing changes and monitoring for any signs of infection.
Rehabilitation and Long-Term Adaptation
Following the initial hospital stay, rehabilitation for a transmetatarsal amputation focuses on regaining strength and mobility. Physical therapy plays a central role, helping individuals adapt to changes in their gait and balance. Common challenges during rehabilitation include potential skin breakdown and instability, influenced by the decreased foot length. Therapists work with patients to address these issues and improve their ability to move safely and independently.
Long-term adaptation often involves specialized footwear or custom orthotics to support the remaining foot and distribute weight evenly. These devices compensate for the loss of the forefoot, which normally plays a significant role in weight-bearing and propulsion during walking. Some individuals may benefit from partial foot prosthetics, custom-molded inserts designed to restore the foot’s length and improve its cosmetic appearance and function within a shoe. Ongoing foot care is important, particularly for individuals with conditions like diabetes, to prevent new complications and maintain the residual limb’s health. Regular check-ups ensure proper fit of adaptive devices and address any changes in foot health.