Lesser Metatarsophalangeal Instability: Presentation, Management, and Outcomes

Abstract

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