What Is Transmetatarsal Amputation?

Transmetatarsal amputation (TMA) surgically removes a part of the foot that includes the metatarsals, which is used to treat a severely infected foot or a foot with lack of oxygen supply.

Transmetatarsal amputation (TMA) involves surgical removal of a part of the foot that includes the metatarsals. Metatarsals are the five bones located between the ankle and toes in each foot.

TMA is a relatively common operation performed to treat a severely infected foot or a foot with lack of oxygen supply (ischemic). Surgeons resort to this type of surgery when all other nonsurgical options to save the foot or limb have failed. Removing the infected part prevents the infection from spreading to the other parts of the limb and thus saves the limb in the long run.

Transmetatarsal amputation (TMA) is required to stop further loss of tissue from the foot that is damaged because of the following conditions:

• Chronic forefoot ulceration
• Forefoot gangrene (tissue death due to lack of blood flow) 
• Combination of above two complicated by diabetes
• Severely crushed forefoot due to a major accident

Before surgery

• The patient will be admitted the night before the surgery and will not be allowed to eat or drink anything 12 hours before the surgery.
• Necessary medicines, as advised by the doctor, can be taken with few sips of water.

During surgery

• The surgeon may give general anesthesia to the patient to keep them asleep and free from pain. Alternatively, they will give a spinal anesthesia to the patient to numb the surgery area. 
• First, the surgeon will make several incisions (cuts) on the patient’s forefoot. 
• The surgeon will cut and remove any damaged or infected bones. 
• Next, the surgeon will cut all the nerves, blood vessels, and tendons. 
• If the infection is severe, the surgeon will pack the surgical wound with sterile bandages and keep it open to heal. Or, the surgeon will close the wound with sutures or staples. 
• The surgeon may place a skin graft from a donor or another part of the patient’s body to cover the wound. 
• The surgeon may clip the wound and attach it to the drains to remove the extra blood and fluid discharge. 
• The surgeon will clean the wound with a sterile solution and then apply a bandage.

After surgery

• The patient will be shifted to the general ward and observed for several hours.
• Antibiotics and analgesics will be initiated. Intravenous (IV) fluids will be continued.
• The bandage will be removed usually on the third day, healing of the wound will be checked, and the wound will be cleaned and bandaged again.
• The patient will be discharged after a hospital stay of 5-14 days.

Every surgery carries some complications. Transmetatarsal amputation (TMA) is a high-risk surgery with possible complications such as the following:

• Need for further amputation: Infection of structures adjacent to the wound may damage the limb further, and amputation may be required.
• Wound infection: Diseases, such as diabetes, increase the likelihood of a wound infection.
• Delayed healing: Co-existing conditions, such as diabetes mellitus, ischemic heart disease, hypertension, and chronic kidney disease, may hamper the healing.
• Nonhealing wound
• Heterotopic ossification: This is an abnormal growth of the bone in other tissues such as muscle and tendons.
• Joint contracture: It is the restricted movement of the joint closest to the part that is amputated.
• Phantom sensation and phantom pain: This is the feeling that the amputated part is still there, and it is painful.
• Blood clot in the legs
• Blood clot in the lungs

If the patient has diabetes, they will have to ask their doctor about diabetic foot care.

The patient needs to wear a splint, boots, or special shoes, such as customized footwear (e.g., steel implants in the soles of shoes), to support the remaining part of their foot. 

The patient needs to lie down and raise their leg to a level above the heart to alleviate the swelling. After the pain and swelling subside, they will need a physical therapist to learn a few exercises to resume mobility and strength in the operated foot. 

Ideally, the wound should heal completely in approximately four to eight weeks. After the wound healing, the patient can opt for an artificial foot.

The switchover from one’s own foot to an artificial foot may cause mental distress for the patient, and adjusting to this new change in life can be a long process. Hence, during this phase, professional counseling of the patient is essential.