Comparison of Multiligament Reconstruction in Individuals With BMI >30 and <30 kg/m ²

Background: Despite the growing clinical relevance of obesity in the context of multiligament knee injuries, there remains a paucity of data evaluating patient-reported outcomes in this population. Purpose: To compare clinical and functional outcomes, including postoperative patient-reported outcome measures (PROMs) and complication/revision rates, of multiligament knee reconstruction (MLKR) in individuals with a body mass index (BMI) >30 kg/m 2 versus <30 kg/m 2 at a minimum 2-year follow-up. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review was performed to identify all patients who underwent MLKR between 2001 and 2022 at a single institution. Patients with a BMI >30 kg/m 2 were propensity-matched to patients with a BMI <30 kg/m 2 on a 1:1 basis by age, sex, laterality, and Schenck classification (knee dislocation). Medical records were reviewed for patient characteristics, time to surgery, year of surgery, number and type of ligament interventions, graft choice, single versus staged reconstruction, and concomitant injuries. Postoperative clinical examination findings and PROMs for each cohort, including visual analog scale score, Tegner activity scale score, Lysholm score, and International Knee Documentation Committee (IKDC) subjective score, were analyzed and compared. Postoperative complication and revision rates were evaluated and compared. Results: Of 158 patients, 79 patients with a BMI <30 kg/m 2 (mean age, 31.0 ± 11.5 years; mean BMI, 25.8 ± 3.0 kg/m 2 ) were matched to 79 patients with a BMI >30 kg/m 2 (mean age, 32.8 ± 9.5 years; mean BMI, 37.1 ± 5.8 kg/m 2 ). There were no significant differences between cohorts regarding age, sex, laterality, and Schenck classification ( P ≥ .100); however, patients in the BMI >30 kg/m 2 group had greater numbers of posterior cruciate ligament reconstruction. The mean follow-up was 7.5 ± 4.8 years for the BMI <30 kg/m 2 cohort and 7.2 ± 4.8 years for the BMI >30 kg/m 2 cohort ( P = .229). Patients with a lower BMI (<30 kg/m 2 ) had significantly better postoperative mean IKDC (79.3 ± 18.7 vs 67.9 ± 21.2; P = .004), Lysholm (85.1 ± 17.1 vs 75.7 ± 21.0; P = .007), and Tegner (5.1 ± 2.0 vs 4.4 ± 1.7; P = .041) scores. The BMI >30 kg/m 2 group also had significantly more postoperative complications ( P = .028). However, there was no significant difference between the 2 cohorts in terms of reoperation rate or conversion to total knee arthroplasty ( P ≥ .189). Conclusion: Patients who undergo MLKR and have a BMI >30 kg/m 2 demonstrate significantly decreased postoperative PROMs when compared to patients with a BMI <30 kg/m 2 . Increasing BMI significantly increased the incidence of complication rates after MLKR.