The outcome of first metatarsophalangeal joint arthrodesis using a locking plate
Background: Arthrodesis of the first metatarsophalangeal joint (MTPJ) is a common and frequently performed procedure in the practice of orthopaedic foot and ankle surgery. Fusion techniques and preferred surgical implants have significantly evolved during recent years. It is however still under debate which surgical device provides the best outcome. One of the modern techniques described includes the use of a dorsal anatomical locking plate. These plates are usually used in combination with an additional lag screw over the arthrodesis site. The aim of this study was to assess the outcome of arthrodesis of the first MTPJ using a dorsal locking plate without making use of additional lag screw fixation.
Methods: We retrospectively assessed data at a private orthopaedic practice. All patients who had a first MTPJ arthrodesis with an anatomical locking plate system between 2010 and 2016 were identified. No additional interfragmentary compression screw fixation was done in any of these cases. Standard standing dorsoplantar and lateral x-rays of the foot were taken 3 months after surgery. As a primary objective, these radiographs were assessed to determine the rate of radiological union. As a secondary objective, any other complications that occurred in the postoperative period were recorded.
Results: We included 115 patients in the study. 15 of these patients underwent bilateral first MTPJ arthrodesis surgery, making the total amount of feet included in the study 130. 86% (n=99) were female and 14% (n=16) were male. The mean age at the time of surgery was 54,7 years (range 37-74). An observed radiological union rate of 97% at 3 months after surgery was recorded. A total of 4 cases (3%) presented with symptomatic non-union. Two of these were successfully revised and progressed to union before the 9-month follow-up. One patient had bilateral surgery for severe rheumatoid arthritis with poor bone quality. No union was achieved even after a revision procedure with bonegrafting. A Keller type resection arthroplasty was eventually performed in this patient. Another secondary complication that was recorded is an overall infection rate of 2.2%.
Conclusion: The results of this retrospective study suggest that an overall positive outcome can be expected when fusing the first MTPJ with the use of a locking plate system. High union rates can be expected without the need for additional interfragmentary lag screw fixation.
Level of evidence: Level 4