SLR - July 2018 - Michael E. Hoenig

Treatment of Brachymetatarsia Involving the Great Toe

Reference: Hui Take Kim, Sung Min Hong, MD, and In Hee Kim, MD. Treatment of Brachymetatarsia Involving the Great Toe. Journal of Bone and Joint Surgery, April 2018.

Scientific Literature Review

Reviewed By: Michael E. Hoenig, DPM
Residency Program: Sanford Health Podiatric and Surgery Residency, Fargo, ND

Podiatric Relevance: Brachymetatarsia has several treatment options and can be associated with many complications. Complications include decreased ROM of the first metatarsophalangeal joint, hallux valgus and plantar flexion of the metatarsals. These complications often result in additional surgery and decreased patient satisfaction. Treatment by distraction osteogenesis also carries several complications, such as callus fractures, pin breakage and pin infection. The authors of this article have proposed a one-stage lengthening procedure. This technique combines lengthening and shortening of adjacent bones to achieve a function parabola.

Methods: This study included 24 feet consisting of 15 patients treated for first ray brachymetatarsia. Preoperative planning consisted of AP radiograph manipulation with Adobe Photoshop and Microsoft Powerpoint. In all patients, the first metatarsal was noticeably shorter than the second. Indications included pain from secondary deformities due to the brachymetatarsia but also cosmetic appearance. Patients were assessed with AOFAS and ROM of the first MTPJ. Careful presurgical planning took place using radiographs and computer programming to form and visualize a more acceptable parabola based on patients' foot type. This allowed the authors to decide which metatarsals to lengthen and/or shorten. The first metatarsal lengthening was done through a medial incision with a step-cut osteotomy on the medial side of the metatarsal. Two vertical half-cuts at the proximal and distal ends of the osteotomy were decided after deciding on a small fixation plate. The metatarsal was lengthened as planned keeping the hallux dorsiflexion to an acceptable degree of motion. Distraction of the osteotomized pieces were kept overlapped, and then plate fixation with at least two screws in each end to hold the fragments was placed. The space was filled with either interposition bone graft from ilium, excised fragment of metatarsal or synthetic hydroxyapatite. Similar fashion was used to lengthen lesser metatarsals as needed; however, a K-wire was used for fixation of bone graft rather than a plate. No soft-tissue procedures were used for the first metatarsal; however, extensor Z-lengthening and plantar plate capsulotomies were used on lesser metatarsals as needed. Postoperatively, patients were in a short leg boot/cast for six weeks and were partial weightbearing to heel.

Results: In all 24 feet, an acceptable parabola was created at the metatarsal head and digit tips. All patients fused without nonunion and no major complications. Most patients experienced mild reduction in first MPJ ROM. AOFAS scores improved from 88.3 preoperatively to 98.1 at the latest follow-up.

Conclusions: This technique for first metatarsal brachymetatarsia offers a one-stage procedure to improve functional and cosmetic outcomes. The procedure both lengthens and shortens all metatarsals as needed to provide a functional parabola with minimal complications.    

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