Which joint is fused in the Lapidus procedure?

Which joint is fused in the Lapidus procedure?

• A. First MTP Joint
• B. Naviculo-Cuneiform Joint
• C. First Tarsometatarsal Joint
• D. Subtalar Joint

Answer: (C)

Lapidus procedure fuses the first tarsometatarsal joint. This involves arthrodesis between the base of the first metatarsal and the medial cuneiform, sometimes described as stabilizing the first ray at the TMT joint. The goal is to eliminate hypermobility or instability of the first ray (often with metatarsus primus elevatus) that drives hallux valgus deformity. By fixing this joint, the first ray becomes a solid lever under load, allowing proper realignment of the big toe and improved forefoot mechanics. This procedure targets the TMT joint specifically, not the first MTP joint, the naviculo-cuneiform joint, or the subtalar joint.

Lapidus procedure fuses the first tarsometatarsal joint. This involves arthrodesis between the base of the first metatarsal and the medial cuneiform, sometimes described as stabilizing the first ray at the TMT joint. The goal is to eliminate hypermobility or instability of the first ray (often with metatarsus primus elevatus) that drives hallux valgus deformity. By fixing this joint, the first ray becomes a solid lever under load, allowing proper realignment of the big toe and improved forefoot mechanics. This procedure targets the TMT joint specifically, not the first MTP joint, the naviculo-cuneiform joint, or the subtalar joint.