Does the Presence of Pes Planus Deformity Increase Recurrence of Hallux Valgus Deformity Following Surgery?

CATEGORY: Bunion INTRODUCTION/PURPOSE: Factors linked with increased risk of developing Hallux Valgus include; shod footwear, genetic factors, metatarsal morphology, ligamentous laxity and Pes Planus. With regards to Pes planus, it has been suggested that the loss of the medial longitudinal arch in Pes Planus increases Hallux plantar medial pressures and drives deformity during heel rise. There is little in the literature regarding whether Pes Planus is associated with increased recurrence rates. Given this is a potentially modifiable risk factor we believe the risk of recurrence should be studied. This paper reports the results of a retrospective study following up 183 consecutive Hallux valgus cases. The primary objective is to evaluate whether pes planus is associated with increased recurrence following treatment. METHODS: Retrospective review of consecutively treated patients from 07/03/2008 to 05/12/2017. Patients were typically followed up for six to twelve months depending on any additional factors that require follow up. X-rays were performed routinely at six weeks, three months and many had x-rays at six and/or 12 months for additional pathology. We examined radiological markers including Sesamoid location (using the Hardy and Clapham Classification), Hallux Valgus Angle (HVA), Intermetatarsal Angle, Meary’s angle and Talonavicular uncovering. 183 cases were reviewed, 12 were excluded due to previously amputated second toes, Hallux Varus, revision surgery and only 6 weeks follow up. This left 171 cases of which 75 had Pes Planus (Meary’s angle < -4°). RESULTS: Table 1 describes the preoperative HVAs we encountered and the correction achieved along with frequencies. Postoperative measurements were taken off weight bearing x-rays. The incidence of recurrent HVA > 15° was significantly higher in those with Meary’s angle < - 4° (Chi-Sq 22.6 P-value 0.000002). Those with a Meary’s angle -20° to -10° had a significantly higher rate of recurrence than ones measuring -10° to -4° (Chi-Sq 9.7 P-value 0.0018 There was no difference in progression of recurrent deformity between those initially corrected to HVA < 15° (Chi-Sq 0.26 P- value 0.61) and those not. Multiple regression analysis revealed there was no meaningful association with sesamoid location or pes planus with recurrence of Hallux Valgus deformity. CONCLUSION: Our results demonstrate a link between Preoperative Pes Planus deformity and increased recurrence rates of Hallux Valgus deformity following surgery. Consideration of correction of pes planus and appropriate consent of recurrence rates should therefore be undertaken in treatment of hallux valgus in the presence of pes planus