Outcomes of 2B Adult Acquired Flatfoot Deformity Correction in Patients With and Without Spring Ligament Tear

Abstract

Background: It is currently unclear how injury to the spring ligament (SL) affects the preoperative presentation of adult acquired flatfoot deformity (AAFD) or the outcome of operative reconstruction. The purposes of this study were to assess the preoperative features and pre- or postoperative function of patients who underwent direct operative repair of an SL tear compared to those without a tear. Methods: 86 patients undergoing operative correction of grade 2B AAFD by a single fellowship-trained foot and ankle orthopaedic surgeon were reviewed at an average follow-up of 45.9 months. There were 35 feet found to have an SL tear that underwent concomitant debridement and direct repair of the SL. Patient charts were reviewed for demographic information, preoperative visual analog scale (VAS) pain level, and their Foot and Ankle Ability Measure (FAAM) activities of daily living (ADL) and sports subscales. Preoperative radiographic parameters were assessed. Patient outcomes of VAS pain, FAAM-ADL, and FAAM-Sports were collected and compared between groups. Results: Those with an SL tear had significantly lower FAAM-ADL and sports scores, with higher VAS pain scores preoperatively. Patient age, talonavicular uncoverage percentage, and talonavicular angle were found to be associated with spring ligament degeneration. At final follow-up, patients demonstrated a significant improvement in all outcome parameters, with no statistical difference found with patient satisfaction, final postoperative VAS pain, FAAM-ADL, or FAAM-Sports in those requiring a repair of their SL as compared to the control group. Conclusion: Increasing patient age, increasing talonavicular uncoverage percentage, and decreasing talonavicular angle are all independently associated with increased likelihood of patients with AAFD having an SL tear. At follow-up for operative treatment of grade 2B AAFD flatfoot with our approach, we found no clinical outcomes difference between those without SL tears and those with SL tears treated with concomitant SL debridement and repair. Level of Evidence: Level III, retrospective cohort study.