Insignificant correlation between post-operative swelling and early functional outcome after ankle fusion

Introduction Swelling is a common complication following a foot and ankle surgery, and is one of the most prevalent complaints that patients present at the clinics. While it affects patients’ satisfaction, the relevance between the swelling and clinical outcome remains unclear. Material and Methods This study assessed volume of foot and ankle swelling in 112 patients with history of ankle fusion, the patients’ Foot Function Index (FFI) score, and patients’ satisfaction. The relationships between swelling volume and early outcomes were analysed with Pearson’s correlation coefficient and a scatter plot. Results The mean of swelling volume increase was 120.0 ± 96.2 ml (range 5 ~ 400 ml); pre-operative FFI score mean was 73.7 ± 4.8 % (range 68 % ~ 81 %), 3 months post-operative FFI score mean was 32.8 ± 5.0 % (range 22 % ~ 56 %) and satisfaction scale’s median was 1 (satisfied). In the correlation analysis, while the meaningful Pearson’s correlation coefficient was found with satisfaction scale, swelling volume showed a weak correlation of Pearson’s correlation test with FFI scores (R value = 0.190; p value = 0.045). Conclusions This study revealed that the swelling of the foot and ankle following ankle fusion surgery are not associated with functional clinical outcome. However, because it affects the patients’ satisfaction, we emphasize the need to identify the problem and management of the swelling, while assuring them that the swelling does not correlate with the early functional outcome.