Minimally Invasive Distal Metatarsal Metaphyseal Osteotomy of the Lesser Toes: Clinical, Radiologic, and Pedobarographic Outcomes

Abstract

Background: The minimally invasive distal metatarsal metaphyseal osteotomy (DMMO) is a percutaneous operative technique with the aim to relieve the symptoms of metatarsalgia. To our knowledge, no previous research has analyzed both pre- and postoperative pedobarographic data including the changes in plantar pressure.

Methods: Thirty patients (31 feet) were operated on with a DMMO and included in a prospective study. Clinical, radiologic, and pedobarographic outcomes were evaluated in comparison with the preoperative parameters. The American Orthopaedic Foot & Ankle Society (AOFAS) forefoot score, the Foot Function Index (FFI), the Foot and Ankle Outcome Score (FAOS), and a visual analog scale (VAS) for pain were used in order to assess clinical parameters. Radiographs were taken to compare metatarsal lengths. The pedobarographic analysis served to determine plantar peak pressure (PPP) beneath the metatarsophalangeal (MTP) joints.

Results: All scores indicated a significant mean pre- to postoperative improvement (AOFAS = 31.9 points, FAOS = 16.3%, FFI = 24.3%, VAS pain = 4.1 points, VAS general limitation = 3.3 points) (P < .05). PPP was substantially reduced in the relevant area (M6 [plantar area beneath the second and third MTP joint] had a mean pre to post PPP = 14.15 N/cm²) and concurrently higher in the lateral and medial MTP joint areas (M5 mean pre to post = +14.37, M7 pre to post = +7.11). Our mean metatarsal shortening was 6.6 mm. However, our findings do not demonstrate a significant correlation between metatarsal length relationships and the prevalence of metatarsalgia.

Conclusion: Our results demonstrate a significant improvement in clinical scores and PPP. A statistically significant relation between metatarsal length and the prevalence of metatarsalgia was not found in this prospective case series.

Level of evidence: Level IV, case series.

Keywords: metatarsalgia; minimally invasive metatarsal osteotomy; plantar pressure.