Summary

Patient reported outcomes were collectively lower among obese patients with multi ligament knee injuries and those whose injury was classified as ultra-low velocity (ULV-MLKI).

Abstract

Purpose

To perform a systematic review to determine if body mass index (BMI) has an impact on the surgical outcomes of patients with multi-ligament knee injuries (MLKI). Specific aims were to assess whether or not BMI serves as a risk factor for MLKI complications and compare surgical, non-surgical, functional and medically relavent costs between obese and nonobese patients with MLKIs.

Methods

Pubmed and EMBASE databases were searched according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Patient reported outcome scores (PROS) recorded included: Lysholm score, Internation Documentation Knee Committee (IDKC) score, and Tenger activity score pre and post operative. Additionally, a wide array of complications were included, with comparison of complications between papers. Methodologic quality of studies was evaluated by Coleman Methodology Scores (CMSs) and bias assessment was evaluated by Methodological Items for Non-randomized Studies (MINORS).

Results

Twelve studies were included for analysis. Of the four papers that assessed PROS - all reported Lysholm, pre and post-operative Tegner, and IKDC were lower for obese or ultra-low velocity MLKI (ULV-MLKI) patients versus non-obese patients. Collectively, hardware removal (0% vs. 6.4%; p=0.0082), revision surgery/graft failure (7.5% vs. 8.9%; p=0.0220), and arthrolysis/MUA (9.3% vs. 18.1%; p=0.0182) were higher among nonobese patients, while there was no statistically significant difference in infection rates (5.9% vs. 1.7%; p=0.8310), concomitant vascular injuries (9.6% vs 4.7%; p=0.6167) and nerve injuries (24.1% vs. 10%; p=0.339). Other studies found the average BMI of patients with MLKI complications such as post-operative stiffness (30.07 ± 8.00) and vascular injury (31.3 ± 8.6) to be in the obese range. Further, nonobese patients reported a statistically significantly less number of physical therapy visits (30 vs 40; p=.025) and subsequently lower mean costs for physical therapy ($1,480.28 vs $1,987.23; p=.014).

Conclusions

Patient reported outcomes were collectively lower among obese patients with MLKIs and those whose injury was classified as ultra-low velocity (ULV-MLKI). Non-obese patients demonstrated had higher rates of hardware removal, revision surgery/graft failure, and need for arthrolysis/MUA, while there was no significant difference in concomitant neurovascular injury or infection rates among the two groups.