A Modified Fixation Method for Talonavicular Arthrodesis in the Treatment of Müller-Weiss Disease: The Use of the Shape-Memory Alloy Staple as an Adjunct.

Objective: Arthrodesis, usage of metallic implants for internal fixation, is commonly employed as the primary treatment modality for Müller-Weiss disease (MWD). Nevertheless, the efficacy of the current methods of fixation leaves room for improvement. Inadequate fixation strength and the risk of fixation failure are both critical concerns requiring attention. This study explored the clinical effects of implementing a modified fixation technique in talonavicular arthrodesis for the treatment of MWD.

Methods: A total of 14 cases diagnosed with MWD undergoing talonavicular (TN) arthrodesis from January 2021 toMarch 2023 were included in the retrospective study. The fixation method for fusion involved the use of screws, with additional support from the shape-memory alloy (SMA) staple. Relevant clinical outcomes and complications were evaluated preoperatively and postoperatively. Paired-samples t-test was used for all data comparisons.

Results: Radiographic evidence confirmed solid fusion, and follow-up evaluations showed satisfactory results in all cases. The American Orthopedic Foot and Ankle Society (AOFAS) scores were elevated from 32.21 ± 4.0 (range: 22-38) preoperatively to 86.5 ± 2.7 (range: 81-90) postoperatively (p < 0.001). The visual analog scale (VAS) scores declined from 7.40 ± 0.8 (range: 6-8.5) preoperatively to 1.21 ± 1.1 (range: 0-3) postoperatively (p < 0.001). The lateral Meary's angle changed from 13.50 ± 5.2 (range: 8-24) preoperatively to 4.14 ± 2.9 (range: 1-11) degrees postoperatively (p < 0.001). The calcaneal pitch angle increased from 10.07 ± 4.0 (range: 5-19) preoperatively to 14.35 ± 4.0 (range: 8-21) degrees postoperatively (p < 0.001). The talar-first metatarsal angle decreased from 11.71 ± 3.8 (range: 8-18) preoperatively to 4.28 ± 3.1 (range: 0-9) degrees postoperatively (p < 0.001). One patient was observed to experience delayed wound healing and wound infection. No nerve damage, malunion, pseudoarthrosis, or fixation failure were observed.

Conclusion: The results indicated that the fusion of the TN joint using a combination of screws and shape memory alloy staples, could lead to favorable clinical outcomes and significantly enhance the quality of life for patients with MWD. This technique is not only safe and effective but also straightforward to perform.