An Analysis of Change in Patient-Reported Outcome Measures Following First Metatarsophalangeal Joint Arthrodesis: Do Baseline Scores or Comorbidities Make a Difference?

CATEGORY: Midfoot/Forefoot INTRODUCTION/PURPOSE: First metatarsal phalangeal joint (MTPJ) arthrodesis is a well established procedure in the treatment of end-stage arthritis. Patient reported outcome measures (PROMs) are an important part of the modern healthcare system. The aim of surgery is to improve pain, function and health related quality of life (HRQoL). The Manchester-Oxford Foot Questionnaire (region-specific) and the Euro-QOL 5 dimension (generic) are both PROMs, known to be sensitive to change following foot/ ankle surgery at 6-months post-procedure (Maher & Kilmartin, J of Foot & Ankle Res, 5: 17, 2012). However we don’t know if baseline scores and the presence of comorbidities influence the change in these PROMs. This is important to understand so that we can identify which patients to offer MTPJ arthrodesis surgery to. METHODS: Aims 1. To identify the change in two patient-reported outcome measures (PROMs) following MTPJ arthrodesis: The Manchester-Oxford Foot Questionnaire (MOxFQ) and the Euro-QOL 5 dimension tool. Do baseline scores make a difference to the change? 2. To describe the impact of co-morbidities on the change in both PROMs. Data was collected prospectively from patients who had undergone a first MTPJ arthrodesis. Patients with complete pre- and post-PROMs data were included in the analysis. PROMs data was collected on average 5.2 months post-operatively. Surgery notes were crosschecked with radiographic findings. A comparative analysis was done between pre and post-operative data using SPSS (version 20). The MOxFQ generates a total score, as well as 3 sub-domain scores for pain, walking/ standing and social interaction. The EQ5D generates a total score and a health today score (visual analogue scale: VAS from 0-100). RESULTS: 90 patients were identified, 52 had complete data. Mean (SD) age 56.9(17.8) years, 78% female. Comorbidities: diabetes 2%, hypertension 21%, rheumatoid arthritis (RA) 43%, current smokers 10%, average (SD) weekly units of alcohol 5.2 (9.1). Most cases were unilateral (94%) and fixed with two screws (87%). 37% had other foot procedures carried out concurrently.Table 1 shows the change in MoxFQ total, domain scores and the EQ5D total score, health today (VAS). The correlation between baseline EQ5D total and the change for this outcome was r=0.6 (p<0.001). The correlation between baseline MOxFQ total and the change for this outcome was r=0.5 (p<0.001). The only comorbidity to have an influence on PROMs was RA- the presence of RA significantly reduced change in EQ5D total (p<0.05). CONCLUSION: Following MTPJ arthrodesis, statistically and clinically significant changes were observed in EQ5D total score, MOxFQ total scores (and all sub-domains). The EQ5D VAS did not change. Baseline scores in both PROMs were correlated with the change scores following surgery- suggesting that we may be able to identify a baseline score which could predict the outcome in PROMs and target who we offer surgery to as a consequence. Comorbidities had little influence on the change in both PROMs following surgery, other than the presence of RA dampening the change in EQ5D total score. Again this is useful to inform pre- operative discussions.