Keywords: Osteochondral Lesions, Osteochondral Lesions of the Talus, Ankle
Introduction/Purpose: Talar osteochondral lesions (OCLs) are a common cause of chronic ankle pain, mechanical symptoms, and disability. Symptomatic lesions often fail to improve with nonoperative treatment, and benefit from surgical intervention. Arthroscopy and microfracture is considered the first line surgical treatment for small and moderate sized symptomatic lesions, with approximately 87% good and excellent results. Yet, there is evidence that these results may degrade over time. There is very little in the literature assessing the impact of obesity on the outcomes following arthroscopy and microfracture of osteochondral lesions of the talus, especially in high body mass index patients. The goal of this study is to evaluate how varying degrees of obesity influence 90 day and 5 year outcomes after arthroscopy and microfracture treatment of talus OCLs.
Methods: This is a retrospective database cohort study using the TriNetX research database. Patients aged 18– 90 years with a body mass index (BMI, kg/m2) taken within three months prior to arthroscopic microfracturing were included. All patients had a minimum of two years of follow-up. The control group included nonobese patients (BMI <30). Obese patients were stratified into BMI groups: 30–34.9, 35–39.9, 40–44.9, and ≥45 kg/m2. Outcomes included 90-day postoperative medical complications and 5-year arthritis and reoperation rates. Categorical variables were analyzed using chi-squared tests and continuous variables were analyzed with student’s t-test. Cox regression was used to compare reoperation free survival rates. A total of 3,629 patients were included in this study: BMI <30 (n = 1504), BMI 30-34.9 (n = 963), BMI 35-39.9 (n = 589), BMI 40-44.9 (n = 355), BMI ≥45 (n = 218).
Results: Because TriNetX hides outcomes <10 to protect patient confidentiality, the higher BMI cohort was sequentially combined with the adjacent, lower BMI group until outcomes were >10 for 90-day complications. The 90-day incidence of deep vein thrombosis was higher in patients with BMI ≥ 35 compared to nonobese patients [OR 2.20 (95% CI, 1.22–3.96), p = 0.007]. The 5-year arthritis rate was higher in all obese cohorts compared to the control (p < 0.05 across all groups). The overall 5-year reoperation-free survival rate was decreased in obese patients with BMI 40–44.9 (81.73%, p = 0.0004) and BMI ≥ 45 (79.39%, p = 0.0003) compared to nonobese patients with BMI < 30 (88.79%).
Conclusion: This study characterized the effects varying degrees of obesity have on outcomes after arthroscopy and microfracture of talar OCLs. All obese cohorts demonstrated higher rates of arthritis at 5 years. Additionally, patients with BMI > 40 had significantly higher reoperation rates at 5 years. These findings can help counsel obese patients with their prognosis after arthroscopic microfracturing for talar OCLs. Given the disproportionate increase in reoperation rates in the morbidly obese cohort following arthroscopy and microfracture, future research addressing the best treatment approach of OCLs in this challenging population is indicated.
