Short-term Results of Magnetic Resonance Imaging after Ankle Distraction Arthroplasty

BACKGROUND: Ankle distraction arthroplasty has emerged as an alternative treatment for ankle arthritis. There are few reports on the magnetic resonance imaging (MRI) findings after distraction arthroplasty. This study sought to determine whether there are positive changes on MRI after ankle distraction and improvements on X-ray. Additionally, patient-reported outcomes and joint range of motion (ROM) after ankle distraction are described. MATERIALS AND METHODS: Thirty-two patients (mean age 49 years) who underwent ankle distraction had pre-operative and one-year postoperative MRIs, which were graded using a modified whole-organ magnetic resonance imaging score (WORMS). Ankle joint space and ROM were measured. A non-validated three-item questionnaire was administered to assess functional outcomes. RESULTS: Although the anterior quadrant of the ankle showed a trend to improvement in cartilage morphology on the postoperative MRI, the WORMS did not demonstrate a significant difference in any of its subcategories. While reduction in joint osteophytes was observed and maintained short term, this was mainly due to resection intraoperatively. X-rays revealed a significant increase in joint space, and there was a significant increase in ankle dorsiflexion. Eight-seven percent of the patients were satisfied with their functional outcome. CONCLUSION: At short-term follow-up, MRI scores after ankle distraction arthroplasty did not demonstrate significant improvement despite positive changes on X-ray and improved clinical outcomes and ankle ROM. Further study on larger patient numbers with longer follow-up is required. LEVEL OF EVIDENCE: IV, Case Series HOW TO CITE THIS ARTICLE: Haleem AM, Galal S, Nwawka OK, et al. Short-term Results of Magnetic Resonance Imaging after Ankle Distraction Arthroplasty. Strategies Trauma Limb Reconstr 2020;15(3):157–162.