Outcomes of 4th Generation Minimally Invasive Bunionectomy on a Limited Cohort of Patients Requiring Revision Bunion Surgery

Submission Type: Hallux Valgus Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Surgical correction of hallux valgus can be achieved through various techniques with minimally invasive surgery (MIS) gaining popularity in recent years amongst surgeons. The use of MIS 1st distal transverse metatarsal and Akin osteotomy has been associated with good functional outcomes and low complication rates. Despite reports of similar functional outcomes, open techniques used prior to the widespread adoption of MIS techniques have been associated with higher rates of complications. This study reports radiographic and clinical results on patients who underwent minimally invasive transverse distal 1st metatarsal and Akin osteotomies by 3 fellowship trained Foot & Ankle orthopedic surgeons due to recurrence of hallux valgus deformity following an initial open bunion surgery. Methods: 20 consecutive patients between 2021 and 2023 with symptomatic recurrent Hallux valgus without 1st tarsometatarsal or metatarsal phalangeal joint arthritis were treated with 4th generation MIS bunionectomy and followed for at least one year. Primary radiographic outcomes include pre and postoperative hallux valgus and 1-2 intermetatarsal angles. Pain relief was measured by VAS scores. Patient Reported Outcomes (PROMS) used were Foot and Ankle Mobility (FAAM) scores in the dimension of activities of daily living (ADL) and sports. PROMS were measured at one year follow-up. Radiographic recurrence was defined as a change in HVA >2.6 degrees between any 2 postoperative radiographs and an HVA >15 degrees. Z-Scores were calculated depending on the patient's demographics based on normative values to assess the deviation from a normal population FAAM scores. Results: There were 19 females and 1 male, with average age of 60 and a mean BMI of 25. Average pre-op HVA and IMA were 29.62 and 12.42 degrees respectively and improved to 11.15 and 5.51 degrees (p < 0.01) at 12 months. There was no significant difference in pre- and post-op IMA and HVA when compared to a cohort of 192 patients who underwent minimally invasive HV surgery. VAS scores improved from 5.37 preoperatively to 1.9 at final follow up (p < 0.01). The average postoperative FAAM ADL score was (86.34 +/- 17.18) and z score was (-0.08 +/- 1.16). The average postoperative FAAM sport score was (66.12 +/- 30.93) and z-score was (-0.26 +/- 1.94). Conclusion: Overall, the results of the study affirm the literature that fourth generation MIS hallux valgus surgery may be a good option in the case of revision procedures. None of the patients had any postoperative complications and the correction of the hallux valgus angles remained significantly improved at 12 months with no recurrence. At this time, the results show a trend toward lower sports FAAM scores postoperatively but the difference from a normal population is not significant in any sub score domain. Longer follow-up is needed to evaluate the trend further. Demographics, Radiographic, and Patient Outcomes Tables