Severity of Achilles Tendinopathy on Preoperative MRI and Short-term Functional Outcomes After Minimally Invasive Zadek Osteotomy.

Background: Limited literature is available to guide surgeons on which patients with insertional Achilles tendinopathy (IAT) may be the best candidates for minimally invasive dorsal closing wedge calcaneal Zadek osteotomy (MIS ZO). We hypothesized that the severity of IAT on preoperative magnetic resonance image (MRI) may correlate with post-operative functional outcomes and help guide patient selection for treatment with MIS ZO.

Methods: Patients who underwent MIS ZO for IAT ± Haglund deformity were identified and retrospectively analyzed. IAT severity was graded on preoperative MRI. Patient Reported Outcome Measurement Information System (PROMIS) scores, complications, and revisions were recorded. Continuous data were compared by analysis of variance with Bonferroni post hoc analysis.

Results: Seventeen patients treated with MIS ZO, with follow-up >6 months, and preoperative MRI met our inclusion criteria. PROMIS pain scores significantly improved in patients with IAT grades 1-3, with 5, 5, and 7 patients, respectively, in each subgroup. In this small series we only identified statistically significant improvements in PROMIS function (P = .031), and mobility (P = .009) scores were only observed in patients with grade 2 pathology. Sixteen of 17 patients (94.2%) were very satisfied with their procedure and would undergo it again.

Conclusion: In this pilot study, we did not find preoperative MRI findings to correlate well with patient-reported outcome scores following MIS ZO.

Level of evidence: Level IV, case series.