Maintenance of Correction of the First Tarsometatarsal Joint Arthodesis Procedure with a First Metatarsal to Second Metatarsal Screw Technique: A Preliminary Report

CATEGORY: Bunion INTRODUCTION/PURPOSE: Fusion of the first tarsometatarsal joint is common for the treatment of moderate to severe hallux abductovalgus deformity. Despite arthrodesis of the first tarsometatarsal joint, recurrence of the deformity remains a concern. The addition of a screw from the 1st metatarsal base to the 2nd metatarsal base allows for increased stability and can help create a “spot weld” between the metatarsal bases to prevent loss of deformity correction. The additional screw construct is termed the intermetatarsal screw in this study. The purpose of the current study is to determine the long-term maintenance of angular correction of the 1st and 2nd intermetatarsal angle, hallux abductus angle, and tibial sesamoid position after undergoing a 1st tarsometatarsal joint arthrodesis with the addition of the intermetatarsal screw. METHODS: A retrospective, single-center chart and radiographic review was performed of 17 consecutive patients who underwent primary hallux abductovalgus correction with a 1st tarsometatarsal joint arthrodesis using the intermetatarsal screw fixation by the senior author. The study period was from January 1, 2017 to May 14, 2018. Three observers independently reviewed radiographic data including preoperative weight bearing, 1st weight bearing, and final weight bearing plain film radiographs. Preoperative films were used if they were within 3 months of the surgery and the radiographic time line for the post-operative intervals were at 12 ± 2 weeks, 18 ± 4 weeks, 26 ± 4 weeks, 52 ± 12 weeks, and the final follow-up visit. Radiographic data evaluated were initial improvement and long-term maintenance of intermetatarsal angle, hallux abductus angle, and tibial sesamoid position. RESULTS: 17 consecutive patients were identified for review that met inclusion criterea. Mean follow up time was 8.12 months (SD ± 3.68). Bony union was achieved in all patients. There was 1 symptomatic recurrent bunion, 1 case of symptomatic hardware, and 1 case of transient neuritis. Average preoperative IMA was 16.05º (±2.34), HAA was 33.05º (±6.24), and tibial sesamoid position was 5.77 (±0.9). Average IMA improvement was 8.38º (±2.21), HAA improvement was 17.25º (±8.21), and TSP improvement was 3.29 (±1.36) positions. Average loss of IMA was 1.03º (±1.24), HAA was 4.14º (±5.34), and tibial sesamoid position was 0.65 (±0.86) positions. Wilcoxon signed rank test showed statistical significance in all radiographic parameters; both in initial improvements and loss of correction (p<0.005). CONCLUSION: The current study shows the addition of an intermetatarsal screw for 1st tarsometatarsal joint arthrodesis has good union rates, a low complication rate, and maintains correction. Further clinical and comparative studies with a larger patient cohort may yield additional useful information.