Insertional Achilles Tendinopathy Repair: Role of BMI in Post-operative Complications and Pain

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Insertional Achilles tendinopathy (IAT) is a common cause of posterior heel pain. Despite appropriate conservative treatment, many patients ultimately require surgical intervention. Wound complications are unfortunately common with surgery on the Achilles tendon as the soft tissue envelope is fragile with poor vascularity. Obesity is a known risk factor for complications after surgery in many orthopaedic subspecialties; however, there is currently a scarcity of literature examining the relationship between obesity and complications in the surgical management of insertional Achilles pathology. The present study aims to assess complication risk in patients undergoing surgical correction of IAT with the hypothesis that patients with class III obesity will have higher complication rates. Methods: This is a retrospective cohort study performed at a single institution. All patients with an established diagnosis of insertional Achilles tendinopathy who underwent secondary repair of the Achilles tendon by four fellowship trained orthopaedic foot and ankle surgeons between November 2013 and November 2023 were included. Patient demographics, surgical outcomes, post-operative complications, and patient reported visual analog pain scores (VAS) at their preoperative and final follow-up appointment were collected via review of the electronic health record. Patients were divided into groups based on body mass index (BMI) according to the WHO Obesity classifications – BMI < 30, those in Obesity Class I & II (30-39.9), and those meeting Obesity Class III (≥40) criteria. Analyses were conducted using one-way ANOVA and chi-squared tests with assumptions set at alpha < 0.05 and beta = 0.8. Results: There were 123 patients (89 female) in this study. The mean age and BMI were 53.64+/-10.62 years and 34.54+/-7.68 kg/m2. A total of 24 patients had documented complications. Compared to the BMI < 40 cohort, the BMI ≥ 40 cohort had increased risk for wound dehiscence (RR 2.72, p = 0.035). Preoperative VAS scores were highest in patients with BMI ≥ 40 (7.09+/-2.61) compared to BMI 30-39 (5.58+/-2.99, p = 0.051) and BMI < 30 (5.02+/-2.76, p = 0.006). Follow-up scores were also higher in those with BMI ≥ 40. No difference was found in change in VAS scores from preoperative to final follow-up visits (p = 0.489) between cohorts. Conclusion: This study adds to current literature, finding that patients with class III obesity had increased risk of postoperative wound complications following surgical intervention for IAT. Additionally, these patients had increased VAS scores with similar magnitude in reduction of pain compared to a cohort without class III obesity, which has not been observed in other studies. Therefore, those considering surgical intervention for IAT should be counseled appropriately on the increased risk of wound complications and pain with higher BMI.