Lesser metatarsophalangeal instability: presentation, management, and outcomes.

Background: Lesser metatarsophalangeal (MTP) instability is a common cause of forefoot pain. In this prospective study, we looked at its presentation, management and outcome.

Methods: We studied characteristics of patients presenting to a specialist foot and ankle clinic with lesser MTP instability. We used the drawer test to diagnose and stage instability. Patients were followed up in clinic or by telephone interview.

Results: We identified 154 patients with lesser MTP instability; 127 (82%) were female, median age was 56 years. One foot was affected in 107 patients (69%). The second toe only was affected in 99 patients (64%) and multiple toes in 52 (34%) but always involving the second toe if multiple toes involved. 150 toes (52%) had Grade 1 instability, 108 (37%) Grade 2 and 21 (7%) Grade 3 instability. Twelve toes (4%) presented dislocated. Ninety nine patients (64%) were treated nonoperatively, using functional taping, shoe modifications, and injections. Fifty five patients (36%) were treated operatively, including lesser toe straightening, flexor-extensor transfer, Weil and Stainsby procedures. At followup, the mean AOFAS score and standard deviation was 69 ± 16.3 for the nonoperative group compared to 67 ± 17.8 in the operative group. The mean pain score and standard deviation was 31 mm ± 23.7 mm for the nonoperative group and 23 mm ± 24.1 mm in the operative group. Thirty-nine patients (52%) were either satisfied or very satisfied with treatment in the nonoperative group compared to 31 patients (66%) in the operative group. None of these differences were statistically significant.

Conclusion: Painful MTP instability is a common cause of forefoot pain. Most patients can be treated nonoperatively. Operatively treated patients had no significant improvement in outcomes with regards to pain or function.