# No differences at return to sport in psychological profiles and results of muscle function tests between females with and without a second ipsilateral or contralateral ACL injury after ACL reconstruction

## TL;DR

This study found no major differences in psychological or muscle function at return to sport between female athletes who did or did not suffer a second ACL injury after surgery.

## Contribution

The study reveals that psychological and muscle function profiles at return to sport do not differ between female patients with or without a second ACL injury.

## Key findings

- No differences in psychological response or muscle function were found between groups.
- Females with a second ACL injury reported slightly less severe symptoms at return to sport.
- Return-to-sport decisions may require more than just psychological or muscle function assessments.

## Abstract

To determine whether psychological response, self-reported knee function and muscle function at return to sport differ between female patients who returned to sport within 12 months after ACL reconstruction (ACL-R) and either did or did not sustain a second ACL injury within 24 months after ACL-R.

This cohort study included female patients from two Swedish registries, who were between 16 and 40 years old, treated with primary ACL-R between 2014 and 2020, who returned to sport (Tegner ≥ 6) within 12 months from ACL-R, and had at least a 24-month follow-up. The primary focus was comparison of psychological and muscle function profiles at return to sport. Unadjusted comparisons of patient-reported outcomes and muscle function tests at the time of RTS were performed between patients who did and did not sustain a second ipsilateral or contralateral ACL injury during the follow-up period.

A total of 344 female patients were included; 40 (11%) sustained a second ACL injury. No between-groups differences were observed in psychological response or muscle function. For self-reported knee function, females with a second ACL injury reported less severe symptoms (83.8 vs. 78.5, mean difference 5.33, 95% CI 0.68–10.31, ES = 0.37, p = 0.024) compared to females who did not sustain a second ACL injury.

There were no differences in psychological response or muscle function between female patients with or without a second ACL injury within 24 months when RTS was achieved within 12 months after primary ACL-R. However, females with a second injury reported slightly less severe symptoms at RTS. Clinically, these findings indicate that the absence of symptoms or psychological concerns at return to sport should not be interpreted as low reinjury risk, and that return-to-sport decisions in female patients may require assessment approaches beyond single time-point patient-reported outcomes or muscle function tests.