Determination of Minimum Clinically Important Difference (MCID) in Visual Analog Scale (VAS) Pain and Foot and Ankle Ability Measure (FAAM) Scores After Hallux Valgus Surgery

Abstract

Background: Minimum clinically important difference (MCID) defines a threshold when determining clinically significant treatment improvement. Visual analog scale (VAS) and Foot and Ankle Ability Measure activities of daily living (FAAM-ADL) are commonly used for measuring hallux valgus correction. This study aimed to determine MCID in VAS pain and FAAM-ADL scores for hallux valgus correction and additionally, to identify variables influencing achievement of the VAS pain MCID. Methods: Patients undergoing hallux valgus surgery were retrospectively included. VAS pain, FAAM-ADL, and pain satisfaction surveys were collected preoperatively and minimum 1-year postoperatively. Using a 6-point Likert-type pain satisfaction scale, patients reporting low postoperative satisfaction scores 1 through 3 were categorized as “dissatisfied,” and high satisfaction scores 4 through six as “satisfied.” One distribution-based method and 2 anchor-based methods were used to calculate MCID. Further, a logistic regression was calculated to determine if one group (defined by sex, pain satisfaction, preoperative VAS pain, concomitant lesser toe deformity correction, and specific hallux valgus correction procedure) had a greater likelihood of achieving the VAS pain MCID threshold. This study included 170 patients with postoperative follow-up averaging 23.6 months. Results: Calculated MCID scores ranged from 1.8 to 5.2 points for VAS pain and 11.1 to 22.7 points for FAAM-ADL. Moderate deformity correction with proximal first metatarsal osteotomy (Ludloff) (OR=2.236, P = .036) or severe deformity correction with first tarsometatarsal arthrodesis (Lapidus) (OR=3.145, P = .046); and higher preoperative pain scores (OR=1.045, P < .010) had significantly higher odds of meeting VAS pain MCID. Conclusion: This study demonstrated MCID values that may indicate significant pain and function improvement after hallux valgus correction. Higher preoperative pain, and utilization of proximal metatarsal osteotomy or first tarsometatarsal arthrodesis for moderate or severe deformity correction resulted in significantly greater likelihood of reaching the VAS pain MCID than utilizing distal metatarsal and/or proximal phalanx osteotomy for mild deformity treatment. Level of Evidence: Level IV, validating outcome measures.

The efficacy and safety of continuous versus single-injection popliteal sciatic nerve block in outpatient foot and ankle surgery: a systematic review and meta-analysis

“…In addition, Sutton et al and Landorf et al have previously determined the minimal clinical important difference (MCID) of foot and ankle surgeries. The authors determined that a difference in VAS score of 0.8 can be considered the MCID [24, 25]. In our study, the difference between two groups in VAS score at 24 h and 48 h were 2.28 points and 1.18, respectively.…”

Emotional Changes and Functional Progressions during Postoperative Rehabilitation in Collegiate Student-Athletes: A Preliminary Study

“…Although statistically significant (a F-value of 10.4 in the time effect with an ES of 0.54), the amount of emotional improvement measured on a VAS was 3 mm (51 to 54 mm). Although limited to quantifying pain, previously established minimal differences on VAS were at least 15 mm [30] or 18 mm [31]. Based on that, the overall degree of emotional improvement after a single session in our study is not clinically meaningful.…”

The Biomechanical Relationship between Hallux Valgus Deformity and Metatarsal Pain

“…is is also in accordance with the higher VAS scores of Meta2 (6.57) and Meta3 (5.72) ( Table 2). However, the previous literature report showed that the VAS index of Meta was slightly more than 5 [24].…”

“…Corresponding to the higher pain percentage of Meta2-3 in the four groups (Figure 4), the VAS pain score increased significantly with increased severity of HV deformity ( Table 2). Previous studies found a positive correlation between HV deformity and metatarsal pain levels [18,24]. Increasing HV severity was also significantly associated with greater Meta pain and decreased foot function [25].…”