Summary

Same-day arthroscopy within 2 years of UKA did not lead to infections following non-robotic medial or lateral UKA, demonstrating that knee arthroscopy can be performed safely and effectively in patients undergoing UKA to address any concomitant pathologies in the non-arthritic, adjacent compartment.

Abstract

Introduction

Several studies have shown that knee arthroscopy prior to arthroplasty increases the risk of postoperative infection. Recent literature suggests waiting a minimum of 3-9 months after knee arthroscopy before undergoing knee arthroplasty (OR: 1.20; CI: 1.01-1.42; p = 0.035). The majority of data in the recent literature is comprised of national insurance databases or joint registries. These registries lack the specific data to determine the true incidence rates, which impedes accurate analysis of infections and revision risks. The purpose of this study was to determine if the rate of infection or implant failure was among patients who underwent knee arthroscopy prior to unilateral knee arthroplasty (UKA).

Methods

A consecutive series of two-hundred twenty-two knees that underwent a fixed-bearing medial or lateral UKA by a single surgeon without robotic assistance between 1999-2021 were included in the study. Patients were included in the preoperative arthroscopy group if they underwent an arthroscopy within 2 years prior to UKA, and the same-day arthroscopy group if they had an arthroscopy on the same day as the UKA was implanted. Patients underwent knee arthroscopy immediately prior to UKA to evaluate the opposite compartment for research purposes. Treatments included partial meniscectomy, and rarely a mild chondroplasty. All patients had postoperative follow-up visits at a minimum of 1 year following arthroscopy. Superficial infection was defined per the CDC criteria, and deep infections were defined as those that required surgical intervention.

Results

One-hundred sixty-one medial and sixty-one lateral UKAs were included. Twenty-four knees were in the preoperative arthroscopy group (18 medial, 6 lateral, age 64.0 ± 11.2 years, BMI=23.1 ± 3.7). Mean time from arthroscopy to UKA was 186 ± 163.9 days (range 28 to 651 days). One-hundred ninety-one knees were in the same-day arthroscopy group (136 medial, 55 lateral UKAs, age 65.7 ± 11.0 years, BMI 27.7±4.6). Seven knees were included in the no arthroscopy group (7 medial UKAs, 0 lateral UKAs, age 65.3 ± 9.5, BMI 30.9 ± 3.0). There were no significant differences in demographics between groups (p>0.05). No deep infections or periprosthetic joint infections (PJI) were seen in any of the groups. There were two superficial infections in the same-day arthroscopy group, both resolved after 14 and 22 days. No superficial infections were seen in the other two groups. There were no significant differences in infection rate between groups (p = 0.861).

Conclusion

Knee arthroscopy at the time of UKA was not associated with risk of superficial or deep infections of the knee after medial or lateral UKA. Knee arthroscopy immediately prior to knee arthroplasty is safe and effective to allow for thorough inspection of the joint.