Validity and Reliability of the American Orthopaedic Foot and Ankle Society Score for the English-Literate Singapore Population With Hallux Valgus.

BACKGROUND: This study aimed to evaluate the reliability and validity of the American Orthopaedic Foot and Ankle Society Metatarsophalangeal-Interphalangeal (AOFAS MTP-IP) score in patients with hallux valgus in Singapore. METHOD: A total of 121 English-literate patients with hallux valgus identified between October 2017 and May 2020 were analyzed. Reliability was assessed via Cronbach α. Construct validity was evaluated through 20 a priori hypotheses by correlating the AOFAS MTP-IP score for hallux and lesser toes with other patient-reported outcome measures (PROMs). Standardized response means (SRMs) were calculated to evaluate responsiveness at 6 months postoperative. Structural validity was evaluated via confirmatory factor analysis (CFA) whereby a good fit was indicated when comparative fit index (CFI) is >0.95, Tucker-Lewis index (TLI) is >0.95 and standardized root mean residual (SRMR) is <0.08. RESULTS: The AOFAS MTP-IP score demonstrated reliability with a Cronbach α of 0.837. Convergent construct validity was confirmed when all a priori hypotheses were fulfilled. Structural validity was established with our AOFAS MTP-IP score model that displayed good fit for a 1-factor structure (CFI = 0.988, TLI = 0.960, SRMR = 0.034). Responsiveness of the AOFAS MTP-IP score for hallux was demonstrated by an SRM score of 1.28. CONCLUSION: The AOFAS MTP-IP score displayed adequate reliability and validity among English-literate patients in Singapore with an operatively managed hallux valgus. LEVEL OF EVIDENCE: Level III: Retrospective cohort study.

Early Functional, Radiological Outcomes and Satisfaction Rates of Total Ankle Arthroplasty in an Asian Population.

BACKGROUND: Few studies have outlined the outcomes and complications in Asians undergoing total ankle arthroplasty. This study reports the functional, radiological outcomes and satisfaction rates in our Asian population. METHODS: Patients who underwent primary total ankle arthroplasty from 2007 to 2013 were recruited. Outcomes evaluated were the AOFAS Ankle-Hindfoot Score (AHS), Visual Analogue Scale (VAS), and the Short Form 36 (SF-36)questionnaire. Outcome scores were collected prospectively up to 2 years. Patient satisfaction was evaluated on a 6-point scale based on North American Spine Society Low Back Pain Instrument and classified as satisfied or unsatisfied. RESULTS: Forty-one patients underwent primary total ankle arthroplasty. All patients experienced improvements in AHS, VAS, and Mental Component Summary score of the SF-36 at both 6-month and 2-year postoperative interval. The mean AHS score improved from 35 ± 19 points preoperatively to 64 ± 24 at 6 months (P<.001) and 72 ± 26 at 24 months (P <.001). VAS scores improved from 7 ± 2 preoperatively to 3 ± 3 (P < .001) at 6 and 24 months. The Physical Component Summary (PCS) of the SF-36 has an established minimum clinically important difference (MCID) of 5. The mean improvement in PCS in our cohort met this MCID for the PCS; 63% and 71% of patients were satisfied with the procedure at 6 months and 2 years postoperatively, respectively. Revision rate in this series was 9.7%. CONCLUSION: Total ankle arthroplasty has good patient satisfaction rates, with favorable early clinical outcome in Asian patients. LEVELS OF EVIDENCE: Therapeutic, Level II.

Tibial Sesamoid Position Influence on Functional Outcome and Satisfaction After Hallux Valgus Surgery.

BACKGROUND: During hallux valgus surgery, the abnormal position of the first metatarsal bone relative to the sesamoids is addressed. Our study aimed to investigate the influence of postoperative tibial sesamoid position (TSP) on functional outcome and patient satisfaction after hallux valgus surgery. METHODS: Between February 2007 and November 2011, 250 patients who underwent hallux valgus surgery at our tertiary hospital were followed for 2 years after surgery. They were categorized into 2 groups based on Hardy and Clapham's TSP classification, recorded on postoperative weight-bearing anteroposterior (AP) radiographs: (1) normal (grades I-IV) and (2) outliers (grades V-VII). RESULTS: The mode TSP improved from grade VII preoperatively to grade IV postoperatively (P < .001). The visual analog scale for pain was 1 (95% CI 0, 1) point better in the normal group compared to the outlier group at 2 years after surgery (P = .050), whereas the American Orthopaedic Foot & Ankle Society Hallux Metatarsophalangeal-Interphalangeal Scale was 6 (95% CI 2, 11) points higher in the normal group (P = .009). Patients in the outlier group were also more likely to be dissatisfied with the surgery performed when compared to the normal group (OR 3.881, 95% CI 1.689, 8.920, P = .001). CONCLUSION: We recommend correcting the TSP to grade of IV or less to improve functional outcome and satisfaction after hallux valgus surgery. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Pain Resolution After Hallux Valgus Surgery.

BACKGROUND: Although more than 1500 publications on hallux valgus can be found in the current literature, none of them have reported on the course of pain resolution after hallux valgus surgery. Thus, this study aimed to investigate pain resolution after hallux valgus surgery and to identify predictive factors associated with residual pain at 6 months after surgery. METHODS: We prospectively followed up 308 patients who underwent hallux valgus surgery at a tertiary hospital at 6 months and 2 years after surgery. Multivariate logistic regression analysis was performed to evaluate the risk factors associated with residual pain after surgery. RESULTS: Ninety-four patients (31%) had some degree of residual pain at 6 months after surgery. After excluding 4 patients who developed osteoarthritis of the first metatarsophalangeal joint over the next 18 months, 73 of the remaining 90 (81%) experienced improvement in visual analog scale (VAS) by the 2-years follow-up. Their median VAS improved from 4 (interquartile range [IQR] 3, 5) at 6 months to 0 (IQR 0, 3) at 2 years (P < .001). A higher preoperative VAS increased the risk of having persistent pain at 6 months after sugery (odds ratio [OR] 1.388, 95% confidence interval [CI] 1.092, 1.764, P = .007), whereas a higher preoperative Mental Component Score of SF-36 (MCS) reduced this risk (OR 0.952, 95% CI 0.919, 0.987, P = .007). CONCLUSIONS: As much as 31% of patients will have residual pain at 6 months after surgery. Preoperative VAS and MCS are predictors for residual pain. However, these patients will continue to improve over the next 18 months, with 71% of them being pain free at 2 years after surgery. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Effect of Obesity on Outcome of Hallux Valgus Surgery.

BACKGROUND: Obesity is a global epidemic, but its effect on foot and ankle surgeries is not well defined. This study aimed to investigate the influence of obesity on functional outcome scores, incidence of postoperative surgical site infection (SSI), and repeat surgery after hallux valgus (HV) corrective surgery. METHODS: Between January 2007 and December 2011, 452 patients who underwent HV corrective surgery at a tertiary hospital were evaluated. They were categorized into 2 groups based on their body mass index (BMI): (1) BMI less than 30 kg/m(2) (control); (2) BMI 30 kg/m(2) or more (obese). The patients were prospectively followed for 2 years. RESULTS: Patients in the obese group were significantly older by 4 years (95% CI, 1-7 years) (P = .043). The preoperative American Orthopaedic Foot & Ankle Society Hallux Metatarsophalangeal-Interphalangeal (AOFAS Hallux MTP-IP) Scale and Physical Component Score were 6 points (95% CI, 1-11 points) and 3 points (95% CI, 1-6 points) poorer, respectively, in the obese group (P = .014 and P = .032, respectively). However, the Visual Analog Scale, AOFAS Hallux MTP-IP Scale, Physical Component Score, and Mental Component Score were comparable between the 2 groups at 6 months and 2 years of follow-up (all P > .05). Eleven patients (3%) in the control group and 1 patient in the obese group (2%) developed postoperative SSI (P = .777). Nine patients (2%) in the control group and 7 patients in the obese group (14%) required repeat surgery for complications (P < .001). CONCLUSION: The authors conclude that while it is important to warn obese patients of the significantly higher risk of repeat surgery, these patients should not be excluded from undergoing HV surgery. LEVEL OF EVIDENCE: Level III, retrospective comparative series.