The effect of Charlson Comorbidity Index, race, and surgical complications on postoperative knee outcomes after total knee arthroplasty

Abstract

Introduction

Total Knee Arthroplasty (TKA) is the primary definitive treatment for knee osteoarthritis (OA) and has been essential in helping patients reduce knee pain and regain mobility. There is a need to assess whether various factors such as surgical complications from primary TKA, pre and postoperative range of motion (ROM), Charlson Comorbidity Index (CCI), comorbidities other than CCI, and demographics representative of an outpatient TKA population affect patient-reported outcome measures (PROMs).

Materials and methods

Retrospective chart review was performed on 444 patients who underwent TKA at an outpatient surgical facility. Demographics, qualitative, and quantitative measurements were collected at baseline, 4–6 months, and 1-year postoperatively. Patients were stratified by CCI into low (< 2), moderate (2–4), and high (> 4) risk categories. A generalized linear model was used to assess the relationship between time, complications, risk categories, and Knee injury and Osteoarthritis Outcome Score Joint Replacement (KOOS, JR).

Results

Majority of patients were women (58.9%), non-Hispanic white (81.9%), categorized as moderate risk CCI (78.8%), with 22.5% experiencing complications post-TKA. KOOS, JR scores improved over time, with an increase of 18.1 points at 4–6 months and 26.1 points at 1-year post-TKA (p < 0.0001). Surgical complications were linked to a decrease of 3.5 points in KOOS, JR scores, whereas patients with high pre-TKA KOOS, JR scores had an increase of 6.4 points after surgery. Patients who identified as African American experienced an average of 4.7 points lower on KOOS, JR than non-Hispanic whites (p = 0.0211). High-risk patients (CCI > 4) on average, had higher KOOS, JR scores 12 months after TKA. African Americans and those with surgical complications reported Lower KOOS, JR scores.

Conclusions

TKA improved KOOS, JR scores through one year with the greatest improvement in PROM being in higher-risk patients, those without surgical complications. Patients with surgical complications and/or African American race had a lower average KOOS, JR score.