Midfoot arthritis fusion is an operation to permanently stiffen one or more tarsometatarsal (TMT) joints in the midfoot that have become arthritic, typically from previous Lisfranc injury, primary osteoarthritis, or inflammatory arthritis.
An incision is made over the top of the midfoot. The cartilage is removed from the affected TMT joints. The joints are aligned in the correct position and fixed with screws, plates, or staples. Bone graft may be used. Multiple joints can be fused in a single operation. The first, second, and third TMT joints are fused more commonly than the fourth and fifth (which are more mobile and rarely fused). The operation takes one and a half to two hours.
Surgery is recommended for painful midfoot arthritis that has not responded to stiff-soled shoes, orthotics, carbon fibre insoles, injection, and activity modification.
Stiff-soled or rocker-bottom shoes, carbon fibre footplate insoles, corticosteroid injection, activity modification, and weight management.
Weight-bearing X-rays and CT scan. Plan for six to twelve weeks of restricted weight-bearing.
Good pain relief in approximately 85–90% of patients. The midfoot joints contribute very little to normal gait, so fusion causes minimal functional limitation for walking.
Prolonged forefoot swelling for several months.
Screws on the dorsum of the foot may be palpable and may need removal.
Expected at the fused joints but well tolerated.
One or more joints may fail to fuse. Risk approximately 5–10%.
Dorsal cutaneous nerves causing numbness.
Pain under adjacent metatarsal heads.
Particularly in smokers.
Fusion in a suboptimal position.
General or spinal anaesthesia with ankle block.
Non-weight-bearing cast for six to eight weeks. Weight-bearing boot for four to six weeks. Normal footwear at three to four months. Full recovery six to twelve months. Carbon fibre insoles may improve comfort long-term.
X-rays at six weeks and three months. Hardware removal if symptomatic at six to twelve months.
The medial midfoot joints contribute very little to normal walking. Most patients do not notice significant functional limitation. Stiff-soled shoes are generally more comfortable.
Yes — both involve fusion of the TMT joints. The term 'Lisfranc fusion' is used when the arthritis follows a Lisfranc injury; 'TMT arthrodesis' is used for primary arthritis. The surgical technique is the same.