Comparison of Radiographic Outcomes of Non-fixation versus Surface Implant in Plantarflexion Medial Cuneiform Osteotomy in Progressive Collapsing Foot Deformity

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Progressive collapsing foot deformity (PCFD) represents a complex and multi-dimensional pathology characterized by varying degrees of hindfoot valgus and forefoot varus. Multiple surgical options are available to plantarflex and stabilize the medial column in the coronal plane. The plantarflexion opening wedge medial cuneiform osteotomy (Cotton) has been an effective and commonly utilized procedure to address this residual supination deformity. However, the use of internal fixation across the osteotomy is highly variable. The goal of this study was to compare the maintenance of correction and rates of complication between non-fixated and surface implant Cotton osteotomies. Methods: Consecutive patients treated surgically by a single institution made of fellowship trained senior surgeons from over a 7-year period with a Cotton osteotomy for PCFD were identified. 60 procedures with greater than 6 months radiographic follow up were included for analysis. Those excluded did not have weight bearing preoperative radiographs, were referred for revision procedures from outside institutions, presence of metallic wedge/cage implant into the osteotomy site, or presence of single screw fixation across the osteotomy site. Average age at time of surgery was 55 years and mean radiographic follow up was 20.27 months. Lateral talus-1st metatarsal angle (deg) and medial cuneiform length (mm) was measured by a single observer. These measurements were taken at the preoperative, first available weight bearing and final weight bearing follow up. Our primary outcomes were changes in radiographic correction at final follow up and secondary outcomes were radiographic union and reoperation. Results: Successful radiographic fusion occurred in 94% of the non-fixation group and 93% of the surface implant group. Additional surgery was required in only 2 cases in the non-fixation as compared to 17 additional surgeries in the surface implant group, 14 of which were for removal of symptomatic hardware. Average radiographic change in the non-fixation group was 2.51deg for Meary’s angle and 1.5mm for cuneiform length. Average radiographic change for the surface implant group was 2.47deg and 1.2mm. There was no statistically significant difference between radiographic parameters among the two groups. Conclusion: The Cotton osteotomy remains a reliable and reproducible procedure to address residual forefoot supination in the case of PCFD. Our study supports that there is no difference in rates of union, postoperative complication, or ability to maintain radiographic correction at the osteotomy site. Utilizing a non-fixation technique may reduce average surgical time, implant cost and the risk of symptomatic hardware removal while similarly maintaining parameters of radiographic correction. Figure 1: A-C Final follow up weight-bearing foot radiographic series of a postoperative non-fixated Cotton osteotomy. Figure 1-C demonstrates example of measurements taken for Meary's angle and dorsal medial cuneiform length