Reliability of maximal isometric knee strength testing with modified hand-held dynamometry in patients awaiting total knee arthroplasty: useful in research and individual patient settings? A reliability study

<p>Abstract</p> <p><b>Background</b></p> <p>Patients undergoing total knee arthroplasty (TKA) often experience strength deficits both pre- and post-operatively. As these deficits may have a direct impact on functional recovery, strength assessment should be performed in this patient population. For these assessments, reliable measurements should be used. This study aimed to determine the inter- and intrarater reliability of hand-held dynamometry (HHD) in measuring isometric knee strength in patients awaiting TKA.</p> <p><b>Methods</b></p> <p>To determine interrater reliability, 32 patients (81.3% female) were assessed by two examiners. Patients were assessed consecutively by both examiners on the same individual test dates. To determine intrarater reliability, a subgroup (n = 13) was again assessed by the examiners within four weeks of the initial testing procedure. Maximal isometric knee flexor and extensor strength were tested using a modified Citec hand-held dynamometer. Both the affected and unaffected knee were tested. Reliability was assessed using the Intraclass Correlation Coefficient (ICC). In addition, the Standard Error of Measurement (SEM) and the Smallest Detectable Difference (SDD) were used to determine reliability.</p> <p><b>Results</b></p> <p>In both the affected and unaffected knee, the inter- and intrarater reliability were good for knee flexors (ICC range 0.76-0.94) and excellent for knee extensors (ICC range 0.92-0.97). However, measurement error was high, displaying SDD ranges between 21.7% and 36.2% for interrater reliability and between 19.0% and 57.5% for intrarater reliability. Overall, measurement error was higher for the knee flexors than for the knee extensors.</p> <p><b>Conclusions</b></p> <p>Modified HHD appears to be a reliable strength measure, producing good to excellent ICC values for both inter- and intrarater reliability in a group of TKA patients. High SEM and SDD values, however, indicate high measurement error for individual measures. This study demonstrates that a modified HHD is appropriate to evaluate knee strength changes in TKA patient groups. However, it also demonstrates that modified HHD is not suitable to measure individual strength changes. The use of modified HHD is, therefore, not advised for use in a clinical setting.</p

Knee function after anterior cruciate ligament injury. With special reference to muscle power, hop performance and kinematics during high-intensity running

Background: The high incidence of ACL injuries, long time to recovery and the risk of developing knee osteoarthritis at an early stage are areas of major concern for athletes, clinicians and researchers. Furthermore, the decision when to return back to strenuous physical activity after an ACL injury or reconstruction is challenging.Aim: The overall aim of this thesis has been to develop reliable and sensitive methods for evaluation of knee function in patients having sustained an ACL injury during competitive or recreational sports. One of the goals has been to describe lower extremity knee function, in more detail than has been possible before. This would then improve the possibilities to evaluate and guide the patients through rehabilitation and to aid in the decision-making process on when to return to sports.Material, methods and results: Study I - 23 patients were studied 6 months after an ACL injury and 44 patients were studied 6 months after an ACL reconstruction, using a strength test battery. Three strength tests were selected 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). Study II - 30 patients with an ACL injury were studied 11 months after an ACL injury and 35 patients were studied 6 months after an ACL reconstruction. All subjects were tested using a hop test battery comprised of the vertical jump, the hop for distance and the side hop. Results from study I and II showed high test-retest reliability (ICC values ranged from 0.85 to 0.98) for the two test batteries. By using an LSI of 90%, i.e. the performance on the injured side should be ¡Ý90% compared with the uninjured side to be classified as normal, a higher sensitivity was found for the test batteries to discriminate abnormal leg power or hop performance compared with any of the individual tests in the test batteries. For the strength test battery, 60% of the patients after an ACL injury and 95% of the patients after an ACL reconstruction had an abnormal LSI. The corresponding results for the hop test battery were 87% and 91%, respectively. Study III - The test batteries from Study I and Study II were used prospectively on 123 patients (75 males and 48 females) with an ACL injury or having undergone ACL reconstruction. The patients were tested at 4, 6, 12 and 24 months after the ACL injury and pre-operatively, 6, 12 and 24 months after ACL reconstruction. Overall, both men and women increased their muscle function over time, but only a minority exhibited normal values for the muscle power test and the hop test batteries at the 24-months follow-ups. Study IV - High-intensity treadmill running kinematics of the lower extremity were analysed during ongoing fatigue in 12 patients, 10 months after ACL reconstruction, and in five healthy subjects. No significant changes were found in terms of lower-extremity kinematics between the first and last measurements of high-intensity running as a result of increasing fatigue, reaching a median value of 17.5 on the Borg scale of perceived exertion. Already at the beginning of the high-intensity running session, the patients had a significantly less internally rotated foot, more internally rotated hip and more extended knee on the involved leg compared with the non-injured leg and controls. The controls¡¯ kinematics remained unaltered during testing.Conclusions: The test batteries showed high ability to determine deficits in leg power and hop performance after ACL injury and reconstruction. Only a minority of the patients had restored leg muscle power and hop performance at the one and two year follow-ups. High-intensity treadmill running, while developing fatigue, did not change the lower-extremity kinematic pattern 10 months after an ACL reconstruction

Cost-effectiveness of Early Surgery versus Conservative Treatment with Optional Delayed Meniscectomy for Patients over 45 years with non-obstructive meniscal tears (ESCAPE study): protocol of a randomised controlled trial

Introduction Recent studies show similar outcome between surgery and conservative treatment in patients with non-obstructive meniscal tears. However, surgery is still often preferred over conservative treatment. When conservative treatment is non-inferior to surgery, shifting the current standard treatment choice to conservative treatment alone could save over €30 millions of direct medical costs on an annual basis. Economic evaluation studies comparing surgery to conservative treatment are lacking. Methods and analysis A multicentre randomised controlled trial (RCT) with an economic evaluation alongside was performed to assess the (cost)-effectiveness of surgery and conservative treatment for meniscal tears. We will include 402 participants between 45 and 70 years with an MRI-confirmed symptomatic, non-obstructive meniscal tears to prove non-inferiority of conservative treatment. Block randomisation will be web-based. The primary outcome measure is a physical function, measured by the International Knee Documentation Committee ‘Subjective Knee Form’. Furthermore, we will perform a cost-effectiveness and cost-utility analysis from societal perspective and a budget impact analysis from a societal, government and insurer perspective. Secondary outcomes include general health, quality of life, activity level, knee pain, physical examination, progression of osteoarthritis and the occurrence of adverse events. Ethics and dissemination This RCT will be performed in accordance with the Declaration of Helsinki and has been approved by the Ethics Committee (number NL44188.100.13). The results of this study will be reported in peer-reviewed journals and at international conferences. We further aim to disseminate our results to guideline committees

Responsiveness and Minimal Important Change of the IKDC of Middle-Aged and Older Patients With a Meniscal Tear

Background: Responsiveness and the minimal important change (MIC) are important measurement properties to evaluate treatment effects and to interpret clinical trial results. The International Knee Documentation Committee (IKDC) Subjective Knee Form is a reliable and valid instrument for measuring patient-reported knee-specific symptoms, functioning, and sports activities in a population with meniscal tears. However, evidence on responsiveness is of limited methodological quality, and the MIC has not yet been established for patients with symptomatic meniscal tears. Purpose: To evaluate the responsiveness and determine the MIC of the IKDC for patients with meniscal tears. Study Design: Cohort study (design); Level of evidence 2. Methods: This study was part of the ESCAPE trial: a noninferiority multicenter randomized controlled trial comparing arthroscopic partial meniscectomy with physical therapy. Patients aged 45 to 70 years who were treated for a meniscal tear by arthroscopic partial meniscectomy or physical therapy completed the IKDC and 3 other questionnaires (RAND 36-Item Health Survey, EuroQol-5D-5L, and visual analog scales for pain) at baseline and 6-month follow-up. Responsiveness was evaluated by testing predefined hypotheses about the relation of the change in IKDC with regard to the change in the other self-reported outcomes. An external anchor question was used to distinguish patients reporting improvement versus no change in daily functioning. The MIC was determined by the optimal cutoff point in the receiver operating characteristic curve, which quantifies the IKDC score that best discriminated between patients with and without improvement in daily function. Results: Data from all 298 patients who completed baseline and 6-month follow-up questionnaires were analyzed. Responsiveness of the IKDC was confirmed in 7 of 10 predefined hypotheses about the change in IKDC score with regard to other patient-reported outcome measures. One hypothesis differed in the expected direction, while 2 hypotheses failed to meet the expected magnitude by 0.02 and 0.01 points. An MIC of 10.9 points was calculated for the IKDC of middle-aged and older patients with meniscal tears. Conclusion: This study showed that the IKDC is responsive to change among patients aged 45 to 70 years with meniscal tears, with an MIC of 10.9 points. This strengthens the value of the IKDC in quantifying treatment effects in this population