# Muscle Strength Outcomes After ACL Reconstruction Before, During, and After COVID-19-Related Rehabilitation Disruptions

## TL;DR

This study found that female athletes recovering from ACL surgery during the pandemic had worse muscle strength outcomes than males, but showed some recovery by 2022.

## Contribution

The study identifies gender-specific differences in muscle strength recovery after ACL reconstruction during the pandemic.

## Key findings

- Female patients in 2020 and 2021 showed higher extension asymmetry index deficits compared to males.
- By 2022, female patients showed reduced extension deficits comparable to pre-pandemic levels.
- Males exhibited no significant differences in muscle strength across all time frames.

## Abstract

Background: Healthcare restrictions on non-urgent services during the COVID-19 pandemic led to limited access to rehabilitation and delayed treatment, potentially affecting early and mid-term recovery following anterior cruciate ligament reconstruction (ACLR). However, little is known about its specific consequences on muscle strength recovery in recreational and amateur athletes. Objectives: This study aimed to compare short-term clinical outcomes in ACLR patients before, during, and after the pandemic, spanning from 2020 to 2022. Methods: We conducted a retrospective review of 126 patients who underwent ACLR using a hamstring tendon autograft. Patients were grouped based on the timing of surgery and matched for gender. Clinical outcomes and muscle strength parameters were evaluated using an isokinetic dynamometer. Results: Male patients exhibited no significant differences in muscle strength across all time frames (control, 2020, 2021, and 2022). In contrast, female patients who underwent surgery in 2020 and 2021 showed higher extension asymmetry index deficits (Q-AI: 34.09 ± 14.59% and 36.47 ± 16.36%, respectively) and increased flexion deficits in 2021 (H-AI: 25.14 ± 11.41%). Significant differences were observed in quadriceps and hamstring peak torque values, both absolute and normalized. By 2022, the female group exhibited a reduced extension deficit (Q-AI: 18.64 ± 14.49%) comparable to pre-pandemic levels (Q-AI: 19.84 ± 12.37%), indicating a recovery of knee extensor strength. Conclusion: Our study showed gender-specific differences in muscle strength recovery after ACLR during the COVID-19 pandemic, with females showing poorer outcomes than males at 5 months post-operation. Larger studies with extended follow-up are needed to clarify the pandemic’s impact and gender-specific responses.