Four- and Five-Year Analysis of a Prospective Multicenter Study Assessing Radiographic Recurrence and Patient Outcomes Following Triplanar Tarsometatarsal Arthrodesis with Early Weightbearing

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: The majority of hallux valgus (HV) corrections have been historically performed via a two-dimensional, transverse plane-focused approach which has demonstrated high long-term recurrence rates. Recent research demonstrates that 87% of HV deformities are three-dimensional with abnormal frontal-plane rotation of the metatarsal which cannot be completely addressed with a two-dimensional metatarsal osteotomy alone. Correction at the 1st tarsometatarsal (TMT) joint can provide the optimal surgical approach for 3D anatomic restoration at the apex of the deformity, however 1st TMT arthrodesis has historically entailed an extended period of non-weightbearing. This study evaluated the clinical, radiographic, and patient-reported outcomes in patients undergoing instrumented triplanar 1st TMT arthrodesis (TMTA) with a biplanar plating system and protected early weightbearing. Methods: This is a prospective multicenter study that will continue for 60 months post-operatively. Patients 14-58 years old with symptomatic HV (intermetatarsal and HV angles between 10-22° and 16-40°, respectively) and no prior HV surgery on the operative foot were eligible for this study. Patients were treated with an instrumented TMTA procedure using a biplanar plating system with protected early weightbearing. The primary endpoint of this study is radiographic recurrence of HV, with recurrence reported at two different thresholds: post-operative HVA >15° and HVA >20°. Secondary outcomes (changes in radiographic measurements, return to weightbearing and activities, VAS, MOxFQ, and PROMIS-29) were evaluated for statistically significant post-operative improvements. Results: One hundred seventy-three patients (mean [range] age: 41.0 [14-58] years) underwent TMTA with 135 and 68 subjects having completed their 48-month and 60-month visits, respectively. Mean (95% CI) days to protected weightbearing and return-to-full-work were 8.4 (7.3, 9.5) and 57.9 (50.8, 65.0), respectively. Significant improvements in radiographic measures were maintained through 60 months (Table 1). Applying recurrence definitions of post-operative HVA >15° and >20°, 48-month recurrence rates were 7.7% (10/130) and 0.8% (1/130) and 60-months were 3.1% (2/65) and 0.0% (0/65 patients), respectively. Significant improvements over baseline were observed in 24-month VAS pain scores (81% reduction, N=156) and PRO’s (MOxFQ and PROMIS) through 48 months. Fifteen (8.7%) patients required non-elective reoperation (most commonly for hardware removal) and three patients experienced a nonunion. Conclusion: This study’s primary and secondary endpoints provide supporting evidence that instrumented TMTA with biplanar plating is successful in correcting all planes of the hallux valgus deformity with early return to weightbearing and low recurrence while demonstrating favorable clinical and patient-reported outcomes. Patients exhibited meaningful pain reduction after surgery and were able to return to full work in less than two months, on average. Statistically significant improvements in patients’ health-related quality-of-life were observed through 48 and 60 months, post-operatively. Patients will continue to be followed for 60 months total with monitoring for complications, recurrence, and patient satisfaction.