Document Type

Article

Publication Date

2021

Abstract

Background

Criteria for full recovery following anterior cruciate ligament reconstruction (ACL-R) include the ability to achieve >90% limb symmetry in maximal quadriceps strength (QI) and functional hop tests. Additionally, knee extension rate of torque development (RTD) is an important performance metric post-ACL-R. This study investigated the rate of recovery of these performance metrics in a recreationally athletic population.

Purpose

To investigate RTD at 30% (RTD30), 50% (RTD50), and 90% (RTD90) of maximal voluntary isometric contraction (MVIC) recovery rate compared to knee extension peak torque and hop test performance post ACL-R.

Study Design

Descriptive, prospective, cross-sectional single-cohort study.

Methods

Subjects between five months and two years post-primary ACL-R were included from three medical centers. The primary outcomes were QI, RTD30, RTD50, RTD90, and Noyes Hop Test symmetry. Secondary outcome measure was The International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form. All outcomes were performed as part of the standard of care for late-stage ACL-R rehabilitation.

Results

19 subjects (13 male) with a mean age of 27.6 years were included. Subjects were, on average, 37- week (9.5 months) post-ACL-R.The pooled QI and hop tests were 88.8 ± 7% and 86.5±13.5%, respectively. In contrast, the LSI of RTD30, RTD50, and RTD90 values were 76±24%, 65±35%, and 49±33%, respectively. The LSI for RTD50 and RTD90 demonstrated statistical significantly different from LSI of all hop tests (P<0.005) and QI (P<0.05).

Conclusion

Despite the near recovery of MVIC torque and hop performance symmetry, there is still significant deficits in RTD at 9 months post-ACL-R. These results suggest that, following ACL-R, traditional functional performance tests that are used for return to sport and activity decision making are insufficient at capturing significant deficits in knee extension RTD in a recreational athletic population.

Levels of Evidence:2B

Clinical Relevance

Traditional return to sport criteria of quadriceps MVIC and hop testing appear to overlook deficits in knee extension RTD. This may lead to patients being cleared for return to sport prematurely, and subsequently increase the risk of re-injury. Knee extension RTD testing is recommended prior to return to sport.

Comments

Originally published in CPQ Orthopaedics (2021) 5:4.

https://www.cientperiodique.com/journal/fulltext/CPQOS/5/4/98

Download

Share

COinS