Evaluating Prospective Patient-Reported Pain and Function Outcomes after Ankle and Hindfoot Arthrodesis

Abstract

Category: Hindfoot; Ankle Introduction/Purpose: Hindfoot and ankle arthritis and deformity constitute a significant disease burden upon affected patients. Surgical hindfoot and ankle arthrodesis procedures are indicated for pain and instability in such patients and include ankle arthrodesis, tibitalocalcaneal (TTC) fusion, subtalar arthrodesis, and triple arthrodesis. Long-term patient-reported outcomes, including postoperative pain, function, and overall satisfaction, of these procedures have not yet been well-studied. The purpose of this study was to assess the outcomes and prognosis of various hindfoot fusion subtypes along with ankle fusion by using two validated patient-reported outcome measures: The Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) Computer Adaptive Tests (CATs). Methods: The sample consisted of 68 patients presenting to a tertiary care facility for ankle and hindfoot fusion surgeries, including ankle arthrodesis (n= 16), TTC fusion (n= 9), subtalar arthrodesis (n= 25), and triple fusion (n= 18), who had completed preoperative, 12-month postoperative, and 24-month postoperative PROMIS PF and PI CATs. Differences in CAT T-scores were calculated for each patient to create a prognostic estimation of pain and physical function at one and two years postoperative. Mean absolute T-scores for each procedure were also calculated and compared to PROMIS reference population mean (SD) T- scores of 50 (10). The distribution of PROMIS PF and PI T-scores were assessed via a Shapiro-Wilk test, and then paired t-tests were used to compare mean differences in T-scores. Results: Importantly, no statistically significant difference was found between 12-month mean PI scores for patients undergoing any fusion procedure and PROMIS reference population mean. Moreover, triple fusion patients had significantly decreased pain at 12 (delta-T-score= -11.10, p= 0.02) and 24 months (delta-T-score= -12.72, p= 0.01) relative to preoperative T-scores along with increased physical function at 12 (delta-T-score= 6.67, p= 0.04) and 24 months (delta-T-score= 8.70, p= 0.04). PF differences after 12 months were not statistically significant for ankle (delta-T-score= -1.67, p= 0.73), TTC (delta-T-score= 0.04, p= 0.99), or subtalar arthrodesis (delta-T-score= 0.37, p= 0.72). PI decreased after 12 months for ankle (delta-T-score= -14.57, p= 0.16), TTC (delta-T-score =-4.08, p= 0.21), and subtalar arthrodesis (delta-T-score= -0.64, p= 0.53); however, these differences did not achieve statistical significance. Conclusion: Overall, at 12 months after an ankle or hindfoot arthrodesis, patients experienced a similar level of pain to the reference population mean. Following a triple fusion procedure, patients can be provided with an accurate prognosis that they can expect reduced pain and increased physical function that will progressively improve from 12 to 24 months postoperative. No statistically significant difference in pain or physical function at 12 or 24 months for ankle, TTC, or subtalar arthrodesis was found.