Role of first ray hypermobility in the outcome of the Hohmann and the Lapidus procedure. A prospective, randomized trial involving one hundred and one feet.

BACKGROUND: The role of hypermobility of the first tarsometatarsal joint in the etiology of hallux valgus deformity is controversial. Consequently, the need to include an arthrodesis of this joint in the surgical treatment of hallux valgus has been questioned. We designed a study to evaluate the role of arthrodesis of the first tarsometatarsal joint on the outcome of surgical treatment of hallux valgus.

METHODS: A prospective, blinded, randomized study was performed to compare the results of a distal osteotomy of the first metatarsal (the Hohmann procedure) with those of an arthrodesis of the first tarsometatarsal joint combined with a soft-tissue procedure of the first metatarsophalangeal joint (the Lapidus procedure) for correction of a symptomatic hallux valgus deformity. One hundred and one feet of eighty-seven patients were included in the study. Fifty feet had a Hohmann procedure, and fifty-one had a Lapidus procedure. The mobility of the first tarsometatarsal joint was assessed in the preoperative clinical examination. On the basis of this examination, two subgroups were identified: sixty-eight feet with a hypermobile first tarsometatarsal joint and thirty-three feet with a nonhypermobile first tarsometatarsal joint. The patients were assessed clinically and radiographically at two years after the operation.

RESULTS: There was a significant improvement in the score on the great toe metatarsophalangeal-interphalangeal scale of the American Orthopaedic Foot and Ankle Society and in the pain score following both procedures (p < 0.001). With the numbers available, no significant difference between the two procedures or between the subgroups of feet with a hypermobile first tarsometatarsal joint and those with a nonhypermobile joint could be identified. The patient satisfaction rating did not differ either between the two procedures or between the two subgroups. The radiographic results of the two methods were also similar, except for shortening of the first metatarsal, which was significantly greater (p < 0.001) in the Hohmann group, and plantar flexion of the first metatarsal, which was greater in the Lapidus group.

CONCLUSIONS: These short-term results were satisfactory and were comparable with those in previous isolated reports on these two procedures. As no significant differences between the two procedures or between the two subgroups (feet with a hypermobile first tarsometatarsal joint and those with a nonhypermobile joint) were found on clinical assessment, the theory that patients with hallux valgus and a hypermobile first tarsometatarsal joint should be managed with a Lapidus procedure was not supported.

LEVEL OF EVIDENCE: Therapeutic study, Level I-1a (randomized controlled trial [significant difference]). See Instructions to Authors for a complete description of levels of evidence.