Objectives: The rate of childhood obesity in the U.S. has more than tripled since the 1960s. Obesity has been associated with higher rates of conditions such as slipped capital femoral epiphysis and Blount’s disease. There is also a known difference in the kinematics of the obese child’s knee. In discoid meniscus (DM), body mass index (BMI) has been associated with greater tear complexity and worse patient-reported outcomes following arthroscopic management. Few studies have investigated the long-term relationship between BMI and outcomes following DM repair. Purpose of this study is to analyze the influence of Obesity on clinical outcomes following DM repair.
Methods
A retrospective review was conducted to analyze patients who underwent arthroscopic treatment for DM between 2014 and 2020 with minimum 5-year follow-up. The cohort was divided based on patients’ BMI, with a cutoff of under the 85th percentile categorized as normal BMI and 85th percentile and over categorized as overweight and obese. All patients underwent DM saucerization +/- repair. Data collection included demographics, clinical presentation, meniscus pathology, surgical technique, reoperation rates, and complication rates. Patient-reported outcome (PRO) scores including Tegner-Lysholm, IKDC and KOOS for symptom, pain, ADL, sport, and QOL were collected. Wilcoxon rank-sum tests were used for continuous variables and chi-square or Fisher's exact tests for categorical variables. Standard statistical analysis was applied with
Significance
level of p < 0.05.
Results
There were 39 DM patients who underwent surgical management with a median follow-up time of 7.36 years (IQR 4.96 – 7.98). Of the 39 patients included, 14 (35.9%) had a normal BMI less than the 85th percentile and 25 (64.1%) were overweight or obese as defined by BMI equal to or greater than the 85th percentile. Overweight and obese patients were associated with older age compared to normal BMI patients (13.83y v. 11.89y, p<0.001). Between normal vs overweight BMI cohorts, there were no other statistically significant differences in demographic parameters, skeletal maturity, preoperative mechanical symptoms, meniscal stability, intraoperative arthroscopic findings, repeat surgery (2/14 vs 1/25, p=0.25), or return to activity (100% vs 92%, p=0.52). Both normal and overweight BMI groups reported good and similar PROs post-operatively including Tegner-Lysholm (89 vs 95, p=0.38), Pedi-IKDC (90.2 vs 94, p=0.61), KOOS Symptom (88.8 vs 96, p=0.55), KOOS Pain (87.1 vs 97 p=0.06), KOOS ADL (96.5 vs 100, p=0.14), KOOS Sport (90.5 vs 96, p=0.38), and KOOS QOL (77 vs 83, p=0.99).
Conclusion
We demonstrate that patients with a BMI categorized as overweight or obese have comparable good clinical outcomes to patients with normal BMI, at a median of 7 years following arthroscopic treatment for DM. These findings support arthroscopic repair of DM as a safe and effective treatment regardless of BMI. Nearly two-thirds of our cohort were defined as overweight or obese and childhood obesity is increasing, highlighting the importance of exploring this relationship. Future studies should continue to evaluate the long-term relationship between BMI and arthroscopic DM repair outcomes and explore additional predictors of postoperative outcomes, such as waist-hip ratio.