Minimally Invasive Distal Metatarsal Metaphyseal Osteotomy of the Lesser Toes: Learning Curve.

BACKGROUND

Minimally invasive surgery has a shorter surgical time, and in this study we focus on minimally invasive distal metatarsal metaphyseal osteotomy (DMMO). The operation seems to be less complex but requires a high learning curve. We report on our first patients to underline the need for extensive training and great awareness for the risks in the early learning stages.

METHODS

We evaluated 27 patients (mean age = 60.9 years) with a mean follow-up time of 7.2 months. Indication was metatarsalgia, intractable plantar keratosis, and the (sub-)luxation of the metatarsophalangeal joint. Clinical results were evaluated with the 12-item Short Form (SF-12), Foot Function Index (FFI), Foot and Ankle Ability Measure (FAAM), and the American Orthopaedic Foot and Ankle Score (AOFAS). Radiographs and pedobarographic analysis were obtained.

RESULTS

Scores ranged closely to standard value (AOFAS 88.07 points; FFI 93%; FAAM 36.4 points; SF-12 31.27 points). Pedobarography showed significant differences in several forefoot areas. We encountered nonunion/malunion and necrosis of the metatarsal head.

CONCLUSIONS

The aim of this study was to demonstrate the need for intensive training before practicing DMMO. Results show that minimally invasive DMMO requires a high learning curve. Correct handling of the burr is associated with a lot of training. Wrong handling can lead to nonunion/malunion or necrosis.

LEVELS OF EVIDENCE: Therapeutic, Level IV: Case series.