Fusion of the first metatarsophalangeal joint in forefoot arthroplasty.

Forefoot arthroplasty is often recommended for the management of metatarsalgia secondary to rheumatoid arthritis. Concurrently, the first metatarsophalangeal (MP) joint can be fused rather than excised. The results in 37 patients with 64 arthroplasty operations (34 with fusion and 30 with excision of the first joint) show that fusion produced a better cosmetic appearance of the foot, facilitated fitting with normal shoes, and improved overall balance. Pedobarograph measurements during gait indicated that relatively more weight was transmitted through the medial ray when the first metatarsophalangeal joint was fused. Residual pain in the foot was often caused by irregular trimming of the metatarsals. There was no difference in relief of pain between fused and unfused patients. Failure of fusion at the first metatarsophalangeal joint generally was painless. Radiologic degeneration of the interphalangeal (IP) joint of the great toe was relatively common following fusion. MP joint fusion is inadvisable if there is already disease in the IP joint.