Background: The mini-invasive Mitchell-Kramer procedure is a new method of operative correction of mild to moderate hallux valgus deformity. The aim of this study was to describe the technique and evaluate the results of the procedure.
Methods: We evaluated 54 patients who underwent mini-invasive distal metatarsal osteotomy of the first metatarsal with preservation of the lateral cortex of the distal fragment. We did percutaneous 2-mm K-wire stabilization of the osteotomy and did not use cast immobilization with postoperative offloading of the forefoot. We used anteroposterior and lateral foot standing X-rays, visual analog scale (VAS), and American Orthopaedic Foot and Ankle Society (AOFAS) hallux-metatarsophalangeal-interphalangeal scale for the clinical assessment at 18 months' follow-up.
Results: Preoperatively, mean hallux valgus angle was 33.9 degrees; intermetatarsal angle, 14.8 degrees; VAS, 8.9; and AOFAS, 37.0. At follow-up period, hallux valgus angle was 14.2; intermetatarsal angle, 9.7; VAS, 2.6; and AOFAS, 90.7. The average first metatarsal shortening was 2.7 mm. No transfer metatarsalgia was noted at 18 months' follow-up. We found 1 superficial infection, but all patients were satisfied.
Conclusions: The mini-invasive Mitchell-Kramer method was indicated in mild to moderate hallux valgus deformity. Cast immobilization was unnecessary, and full weightbearing was allowed early. Using the minioscillating saw allowed for reduced surgical exposure. The technique of the osteotomy also allowed for rotational stability of the osteotomy.
Level of evidence: Level IV, retrospective case series.
Keywords: Mitchell-Kramer; forefoot disorders; hallux disorders; mini-invasive surgery; percutaneous metatarsal osteotomy.