Impact of the COVID-19 pandemic on early clinical outcome after total knee arthroplasty: a retrospective comparative analysis

INTRODUCTION: To help combat the SARS-CoV-2 (COVID-19) pandemic, elective inpatient procedures have been reduced. The authors hypothesized that a nationwide lockdown would negatively affect the postoperative outcome after total knee arthroplasty (TKA) due to reduced physiotherapy as well as restrictions in external facilities of physiotherapy and rehabilitation. MATERIALS AND METHODS: We conducted a retrospective, comparative study including 41 patients who had undergone primary TKA during the first lockdown of the COVID-19 pandemic from March 2020 to April 2020 and a comparable control group consisting of 47 patients with a minimum follow-up of 6 months before the COVID-19 pandemic from 2019. Relevant end points were the visual analogue scale (VAS) for pain, Knee Society Function Score (KSS), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and range of motion (ROM). RESULTS: The lockdown group had a significantly worse outcome compared to the control group 6 months after TKA regarding WOMAC (p = 0.001), KSS (p < 0.001), OKS (p < 0.001), and length of hospital stay (p < 0.001). We found no statistically significant difference between the groups in ROM (p = 0.132), KSFS (p = 0.933), VAS at rest (p = 0.9.22), and exercise (p = 0.304). CONCLUSION: The COVID-19 pandemic negatively affected early clinical outcome parameters of elective primary TKA at 6 months of follow-up due to restrictions in postoperative care. We believe that standardized protocols for physiotherapy will improve clinical outcomes for TKA in the event of future lockdowns and underline the importance of appropriate postoperative care during this pandemic.