Variability in leg muscle power and hop performance after anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this prospective study was to describe the variability in leg muscle power and hop performance up to 2 years among patients following ACL reconstruction and specifically to illustrate the effects of various criteria for an acceptable level of muscle function. METHODS: Eighty-two patients (56 men and 26 women)with a mean age of 28 years, who underwent ACL reconstruction using either hamstring tendons (n = 46) or a patellar tendon (n = 36), were assessed pre-operatively and 3, 6, 12 and 24 months post-surgery with a battery of three lower extremity muscle power tests and a battery of three hop tests. RESULTS: Leg symmetry index (LSI) values at group level ranged between 73 and 100% at all follow-ups. When the tests were evaluated individually, patients reached an average LSI of ≥ 90% at 24 months. The success rate at 24 months for the muscle power test battery, that is,patients with an LSI of ≥ 90% in all three tests, was 48 and 44% for the hop test battery. The success rate at 24 months for both test batteries on all six muscle function tests was 22%. The criterion of an LSI of ≥ 80% resulted in 53% of the patients having an acceptable level on all six tests,while with a criterion of an LSI of ≥ 100%, none of the patients reached an acceptable level. CONCLUSION: At group level and in single muscle function tests, the muscle function outcome 1 and 2 years after ACL reconstruction is satisfactory in the present study and on a par with the results presented in the literature. However,when using more demanding criteria for a successful muscle function outcome, using batteries of tests or increasing the acceptable LSI level from ≥ 90% to ≥ 95%or ≥ 100%, the results are considered to be poor. It is suggested that this should be taken into consideration when presenting results after ACL rehabilitation, deciding on the criteria for a safe return to sports, or designing rehabilitation programmes after ACL reconstruction. LEVEL OF EVIDENCE: Prognostic prospective cohort study, Level I.

A randomized, controlled study of a rehabilitation model to improve knee-function self-efficacy with ACL injury.

CONTEXT: The Knee Self-Efficacy Scale (K-SES) has good reliability, validity, and responsiveness for patients' perceived knee-function self-efficacy during rehabilitation after an anterior cruciate ligament (ACL) injury. Preoperative knee-function self-efficacy has also been shown to have a predictive ability in terms of outcome 1 y after ACL reconstruction. OBJECTIVE: To evaluate a new clinical rehabilitation model containing strategies to enhance knee-function self-efficacy. DESIGN: A randomized, controlled study. SETTING: Rehabilitation clinic and laboratory. PATIENTS: 40 patients with ACL injuries. INTERVENTION: All patients followed a standardized rehabilitation protocol. Patients in the experimental group were treated by 1 of 3 physiotherapists who had received specific training in a clinical rehabilitation model. These physiotherapists were also given their patients' self-efficacy scores after the initial and 4-, 6-, and 12-mo follow-ups, whereas the 5 physiotherapists treating the patients in the control group were not given their patients' self-efficacy scores. MAIN OUTCOME MEASURES: The K-SES, the Tegner Activity Scale, the Physical Activity Scale, the Knee Injury and Osteoarthritis Outcome Score, and the Multidimensional Health Locus of Control. RESULTS: Twenty-four patients (12 in each group) completed all follow-ups. Current knee-function self-efficacy, knee symptoms in sports, and knee quality of life improved significantly (P = .05) in both groups during rehabilitation. Both groups had a significantly (P = .05) lower physical activity level at 12 mo than preinjury. No significant differences were found between groups. CONCLUSION: In this study there was no evidence that the clinical rehabilitation model with strategies to enhance self-efficacy resulted in a better outcome than the rehabilitation protocol used for the control group.

Self-efficacy of knee function as a pre-operative predictor of outcome 1 year after anterior cruciate ligament reconstruction.

The knee self-efficacy scale (K-SES) has been shown to have good reliability, validity and responsiveness during rehabilitation for patients' perceived self-efficacy of knee function. Determinants of self-efficacy of knee function 1 year after ACL reconstruction have been found to be the patients' internal locus of control and knee symptoms in sports and recreation. The predictive ability of perceived self-efficacy of knee function measured by the K-SES has not been studied in terms of patient outcome after an ACL reconstruction. The purpose of this study was to explore the potential for pre-operative self-efficacy of knee function measured by the K-SES to predict patient outcome in terms of physical activity, knee symptoms and muscle function 1 year after an ACL reconstruction. Thirty-eight patients were evaluated for outcome in terms of physical activity with the Tegner activity scale and the physical activity scale (PAS), knee symptoms with the Lysholm knee scoring scale and the knee injury and osteoarthritis outcome score (KOOS) and knee function with ability tests for muscle function 1 year after ACL reconstruction. Multiple regression and logistic multiple regression analysis were used to evaluate the K-SES as a possible predictor of outcome. The patients' present perceived self-efficacy of knee function (K-SES(Present)) pre-operatively was a significant predictor (P = 0.016) of the patients returning to their intensity and frequency of physical activity (PAS) 1 year after ACL reconstruction, when adjusted for age, gender and pre-injury physical activity level (Tegner(Pre-injury)) (odds ratio = 2.1). The patients' perceived future self-efficacy of knee function (K-SES(Future)) pre-operatively was a significant predictor (P = 0.045) of their self-rated knee function in sports/recreational activities (KOOS(Sports/recreation)) at the 1-year follow-up, when adjusted for age, gender and Tegner(Pre-injury )(R (2 )=0.25). The pre-operative K-SES(Future) was also a significant predictor (P = 0.023) of the patients' knee-related quality of life (KOOS(Qol)), at the 1-year follow-up, when adjusted for age, gender and Tegner(Pre-injury) (R (2 )=0.23). The pre-operative K-SES(Future) was furthermore a significant predictor of an acceptable outcome 1 year after surgery, on the Lysholm knee scoring scale (P = 0.003, odds ratio = 1.7), as well as on KOOS(Sports/recreation) (P = 0.002, odds ratio = 1.6) and knee-related quality of life (KOOS(Qol)) (P = 0.037, odds ratio = 1.4), when adjusted for age, gender and Tegner(Pre-injury). The pre-operative K-SES(Future) was also a significant predictor (P = 0.04) of an acceptable outcome 1 year after surgery, on the one-leg hop for distance (odds ratio = 2.2), when adjusted for age, gender and Tegner(Pre-injury). In conclusion, this study indicates that patients' perceived self-efficacy of knee function pre-operatively is of predictive value for their return to acceptable levels of physical activity, symptoms and muscle function 1 year after ACL reconstruction.

Determinants of self-efficacy in the rehabilitation of patients with anterior cruciate ligament injury.

OBJECTIVE: To explore physical and psychological measures believed to determine patients' perceived self-efficacy in the rehabilitation of patients with anterior cruciate ligament injury. DESIGN: An explorative descriptive study. PATIENTS: A total of 116 patients with an anterior cruciate ligament deficient or reconstructed knee. METHOD: At one visit; 12 months post-injury/reconstruction, patients reported their perceived self-efficacy on the Knee Self-Efficacy Scale. Thirty-nine other measures related to self-efficacy were also documented. A linear regression model was applied to identify determinants of perceived self-efficacy. RESULTS: 40% of the variance in the complete Knee Self-Efficacy Scale was explained by the Lysholm score, Knee Injury and Osteoarthritis Outcome ScoreSport/Recreation, Internal Locus of Control and Locus of Control by Chance. The variance in patients' present perceived self-efficacy was explained to 41% by the same measures. Perceived self-efficacy of future capability was explained to 38% by the variance in the Lysholm score, Knee Injury and Osteoarthritis Outcome ScoreSport/Recreation, TegnerPresent level and Internal Locus of Control. CONCLUSION: Self-reported symptoms/functions and Internal Locus of Control were the most important determinants of self-efficacy in patients with an anterior cruciate ligament injury. In order to strengthen self-efficacy, these determinants should be considered by the clinicians involved in the rehabilitation.

The Achilles tendon Total Rupture Score (ATRS): development and validation.

BACKGROUND: There is a need for a patient-relevant instrument to evaluate outcome after treatment in patients with a total Achilles tendon rupture. PURPOSE: To develop and validate a new patient-reported instrument for measuring outcome after treatment for total Achilles tendon rupture. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 1. METHODS: Development of this instrument consisted of item generation and test construction, item reduction, validation, evaluation of structure and internal consistency, test-retest, and test for responsiveness. The final version, the Achilles tendon Total Rupture Score (ATRS), was tested for validity, structure, and internal consistency (Cronbach's alpha) on 82 patients and 52 healthy persons. A correlation analysis was performed of the ATRS with the 2 validated foot/ankle/Achilles tendon scores, the Foot and Ankle Outcome Score (FAOS) and the Swedish version of the Victorian Institute of Sports Assessment-Achilles questionnaire (VISA-A-S). Structure was evaluated with factor analysis. Test-retest reliability was evaluated on 43 patients. The ATRS responsiveness was tested on 43 patients by calculating the effect size. RESULTS: The total score for the patients ranged from 17 to 100 with a mean (median) of 77 (85) and a standard deviation (interquartile range) of 21.4 (23). A significantly (P < .0001) higher total score was found for the healthy subjects, ranging from 94 to 100 with a mean (median) of 99.8 (100) and a standard deviation (interquartile range) of 1.1 (0). The ATRS correlated significantly (P < .01) with all subscales of the FAOS (r = 0.60-0.84) and the VISA-A-S (r = 0.78). The factor analysis gave 1 factor of importance. The internal consistency was 0.96 as measured with Cronbach's alpha. The test-retest produced an intraclass correlation coefficient of 0.98. The tests for responsiveness showed an effect size between 0.87 and 2.21. CONCLUSION: The ATRS is a patient-reported instrument with high reliability, validity, and sensitivity for measuring outcome after treatment in patients with a total Achilles tendon rupture. CLINICAL RELEVANCE: The ATRS is a self-administered instrument with high clinical utility, and we suggest the score for measuring the outcome, related to symptoms and physical activity, after treatment in patients with a total Achilles tendon rupture.

A test battery for evaluating hop performance in patients with an ACL injury and patients who have undergone ACL reconstruction.

The purpose of this study was to develop a test battery of hop tests with high ability to discriminate (i.e. high test-retest reliability, sensitivity, specificity and accuracy) between the hop performance of the injured and the uninjured side in patients with an ACL injury and in patients who have undergone ACL reconstruction. Five hop tests were analysed: three maximum single hop tests and two hop tests while developing fatigue. Fifteen healthy subjects performed the five hop tests on three separate occasions in a test-retest design. Thirty patients, mean 11 months after an ACL injury and 35 patients, mean 6 months after ACL reconstruction were tested. ICC values ranged from 0.85 to 0.97 for the five hop tests, indicating that all the tests had high test-retest reliability. Sixty-seven percent to 100% of the healthy subjects had normal symmetry (i.e. <10% side-to-side difference) in the five hop tests. Abnormal symmetry in the five hop tests ranged from 43 to 77% for patients with an ACL injury and from 51 to 86% for patients who had undergone ACL reconstruction respectively. The three tests with the highest ability to discriminate hop performance were chosen for the test battery; they were the vertical jump, the hop for distance and the side hop. The test battery revealed a high level of sensitivity and accuracy in patients with an ACL injury (87 and 84%) and in patients who had undergone ACL reconstruction (91 and 88%), when at least one of the three tests was classified as abnormal. To summarise, the test battery consisting of both maximum single hop performances: the vertical jump and the hop for distance and hop performance while developing fatigue: the side hop, produced high test-retest reliability, sensitivity and accuracy. Further, the test battery produced higher values compared with any of the three hop tests individually revealing that only one out of ten patients had restored hop performance 11 months after an ACL injury and 6 months after ACL reconstruction. It is concluded that this test battery showed a high ability to discriminate between the hop performance of the injured and the uninjured side both in patients with an ACL injury and in patients who have undergone ACL reconstruction.

Development of a strength test battery for evaluating leg muscle power after anterior cruciate ligament injury and reconstruction.

A more sports-specific and detailed strength assessment has been advocated for patients after anterior cruciate ligament (ACL) injury and reconstruction. The purpose of this study was to develop a test battery of lower extremity strength tests with high ability to discriminate between leg power development on the injured and uninjured sides in patients after ACL injury and in patients who have undergone ACL reconstruction. Twenty-three patients were tested 6 months after ACL injury and 44 patients were tested 6 months after ACL reconstruction. Twenty-four of the 44 patients were operated on using a hamstrings graft and 20 patients were operated on using a patellar tendon graft. All the patients performed a test battery of three strength tests for each leg in a randomised order. The three strength tests were chosen to reflect quadriceps and hamstring muscular power in a knee-extension and a knee-flexion test (open kinetic chain) and lower-extremity muscular power in a leg-press test (closed kinetic chain). There was a higher sensitivity for the test battery to discriminate abnormal leg power compared with any of the three strength tests individually. Nine out of ten patients after ACL reconstruction and six out of ten of the patients after ACL injury exhibited abnormal leg power symmetry using the test battery. Thus, this test battery had high ability in terms of discriminating between the leg power performance on the injured and uninjured side, both in patients with an ACL injury and in patients who have undergone ACL reconstruction. It is concluded that a test battery consisting of a knee-extension, knee-flexion and leg-press muscle power test had high ability to determine deficits in leg power 6 months after ACL injury and reconstruction. Only a minority of the patients had restored leg muscle power. The clinical relevance is that the test battery may contribute to the decision-making process when deciding whether and when patients can safely return to strenuous physical activities after an ACL injury or reconstruction.