Blasimann A1, Glättli J1, Reinhard C1
1Bern University of Applied Sciences, Department of Health Professions, Bern, Switzerland
Background: A tear of the anterior cruciate ligament (ACL) is one of the most frequent injuries in sports. Often, a surgical intervention follows. Post-surgery, these people often suffer from strength loss caused by arthrogenic inhibition and loss of muscle fibres due to immobilization. To bring people after an ACL repair successfully back to activities of daily life or even sports, an evidence- and criterion-based rehabilitation program is essential. Objective criteria, for example to assess strength, are not only important to reach the next stage of rehabilitation, but also to document treatment success. However, there are a lot of different clinical and physical performance tests done in this area.
Purpose: The aim of this systematic review was to get an overview of different strength tests in people recovering from an ACL repair to judge upon readiness to return to sports (RTS).
Methods: In May 2018, the databases PEDro, PubMed and Cochrane were searched systematically. Randomized-controlled trials (RCTs) working with people after an ACL repair, testing strength as outcome after 3, 6, 12 and/or 24 months after ACL surgery, and comparing two different rehabilitation programs as intervention could be included in this systematic review. Two authors independently screened the found references regarding title, abstract or even full text for inclusion, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. To assess quality of all included studies, the Critical Appraisal Skills Program (CASP) checklist for RCTs was used.
Results: From 246 references initially found, seven RCTs with 390 people after an ACL repair were included into this systematic review. The included studies reached a mean score of 7 out of maximum 9 points after the quality assessment with the CASP checklist. In all included studies, the interventions showed a broad variety. In six studies, strength testing had been executed using an isokinetic dynamometer. However, strength testing differed in starting positions, number of repetitions, range of motion, angle velocity and outcome parameters used. Mainly, strength was labelled as secondary outcome and the knee extensor muscles (quadriceps) were tested.
Conclusion(s): As only few studies with people after an ACL repair fulfilled the inclusion criteria, the results are not valid for all people with an ACL injury. Moreover, the intervention groups and test protocols were heterogeneous. Strength as outcome was not used in every study to judge upon RTS in these people after ACL repair. Therefore, it was not possible to suggest a standardized test for strength or even a cut-off value for people after an ACL repair which would guarantee a safe RTS. Future studies should focus on easy usable, valid and standardized strength measurements in people after an ACL injury as one part to judge upon RTS.
Implications: The isokinetic dynamometer is acknowledged as gold standard for strength testing. However, this expensive tool is time-consuming (measurements, analyses), not very functional and has no standardized test protocol. Therefore, it is not useful for daily practice. Eventually, the hand-held dynamometer or similar tools could be an alternative testing possibility to assess strength in people after an ACL repair.
Keywords: anterior cruciate ligament (ACL), strength testing, return to sports
Funding acknowledgements: This work was partly funded by the Bern University of Applied Sciences by providing working hours for A. Blasimann.
Purpose: The aim of this systematic review was to get an overview of different strength tests in people recovering from an ACL repair to judge upon readiness to return to sports (RTS).
Methods: In May 2018, the databases PEDro, PubMed and Cochrane were searched systematically. Randomized-controlled trials (RCTs) working with people after an ACL repair, testing strength as outcome after 3, 6, 12 and/or 24 months after ACL surgery, and comparing two different rehabilitation programs as intervention could be included in this systematic review. Two authors independently screened the found references regarding title, abstract or even full text for inclusion, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. To assess quality of all included studies, the Critical Appraisal Skills Program (CASP) checklist for RCTs was used.
Results: From 246 references initially found, seven RCTs with 390 people after an ACL repair were included into this systematic review. The included studies reached a mean score of 7 out of maximum 9 points after the quality assessment with the CASP checklist. In all included studies, the interventions showed a broad variety. In six studies, strength testing had been executed using an isokinetic dynamometer. However, strength testing differed in starting positions, number of repetitions, range of motion, angle velocity and outcome parameters used. Mainly, strength was labelled as secondary outcome and the knee extensor muscles (quadriceps) were tested.
Conclusion(s): As only few studies with people after an ACL repair fulfilled the inclusion criteria, the results are not valid for all people with an ACL injury. Moreover, the intervention groups and test protocols were heterogeneous. Strength as outcome was not used in every study to judge upon RTS in these people after ACL repair. Therefore, it was not possible to suggest a standardized test for strength or even a cut-off value for people after an ACL repair which would guarantee a safe RTS. Future studies should focus on easy usable, valid and standardized strength measurements in people after an ACL injury as one part to judge upon RTS.
Implications: The isokinetic dynamometer is acknowledged as gold standard for strength testing. However, this expensive tool is time-consuming (measurements, analyses), not very functional and has no standardized test protocol. Therefore, it is not useful for daily practice. Eventually, the hand-held dynamometer or similar tools could be an alternative testing possibility to assess strength in people after an ACL repair.
Keywords: anterior cruciate ligament (ACL), strength testing, return to sports
Funding acknowledgements: This work was partly funded by the Bern University of Applied Sciences by providing working hours for A. Blasimann.
Topic: Sport & sports injuries; Orthopaedics; Musculoskeletal: lower limb
Ethics approval required: No
Institution: Bern University of Applied Sciences, Bern (Switzerland)
Ethics committee: Ethics Committee of the Canton of Bern (Switzerland)
Reason not required: Ethics approval was not necessary for this type of scientific work (systematic review).
All authors, affiliations and abstracts have been published as submitted.
