Lapidus procedure (TMT1 fusion)

For some patients with bunions, there can be associated midfoot instability, a very large angle between the first and second metatarsal bones or significant flatfoot deformity. In these patients an effective option for correcting the bunion is a Lapidus procedure. This procedure can also be performed to treat midfoot arthritis.

This procedure is effective dealing with very large deformities, unstable midfoot joints, large rotational deformity or patients with very flat feet (planus). In this operation the joint above the big toe joint (the TMT joint) is fused to provide powerful and lasting correction. Most patients have an associated forefoot correction at the same time.

Figure 1: example of a patient who has undergone Lapidus correction for bunion (hallux valgus)

Figure 2: pre and post op lapidus correction

Success rates: over 90% of patients are satisfied with the procedure and have improvement of symptoms. Recurrence of the bunion is very low, because the source of the bunion (the TMT joint) has been fused solid.

Post-operative:

  • Surgery is usually 1 night in hospital.

  • A nerve block is administered to help with post-operative pain

  • 0-2 weeks: elevation at home to reduce swelling in a plaster cast

  • 2-6 weeks: transition to a CAMboot with arch support, start range of motion exercises and start partial weight bearing

  • 6-10 weeks: start full weight bearing in the CAMboot then gradually wean out of this over the four week period.

  • 12 weeks onwards: return to walking in comfortable shoes. Swelling will often be present for up to 6 months.

Download post operative care guide

 

Risks of surgery

  • Swelling, stiffness

  • Infection

  • Wound healing problems

  • Scar sensitivity

  • Ongoing pain

  • Recurrence of symptoms or deformity

  • Further surgery including removal of metal in approximately 10% of patients

  • Non-union (bones not healing)