The accuracy of clinical examination of rotational and sagittal laxity of the knee (original) (raw)
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Computers in Biology …, 2009
Background: The purpose of this study was to investigate about the reliability of measuring anteroposterior laxity within-subjects for in-vivo studies using a navigation system. Methods: The analysis was performed by enroling 60 patients undergoing anterior cruciate ligament ACL reconstruction, and assessing AP laxity during the Lachman and drawer tests. Results: For the navigation system standard deviation for intra-trial measures was 0.7 mm, thus the intratrial repeatability coefficient was 2.2 mm; standard deviation for intra-trial measure was 1.2 mm, while the reference inter-trial repeatability coefficient between expert surgeons was 3.4 mm. Conclusions: In conclusion, this study suggests that KIN-Nav may represent a new method to measure and document AP laxity intra-operatively with improved accuracy and test the effect of surgical treatment in-vivo with higher sensitivity than in the past and this study quantify its reliability for within-subjects studies performed by a single expert surgeon.
Knee Surgery, Sports Traumatology, Arthroscopy, 2012
Purpose The goal of the present study was to evaluate static anteroposterior and rotational knee laxity after ACL reconstructions with two noninvasive measurement devices by comparing the measured results of the operated with the contralateral healthy knees of the patients. Methods Fifty-two consecutive patients were reviewed after isolated single-bundle transtibial ACL reconstruction using a BPTB graft. At a mean follow-up of 27 months, sagittal AP laxity was tested using a noninvasive knee measurement system (Genourob) with an applied pressure of 67 N, 89 N and 134 N. Rotational laxity was measured using a noninvasive rotational knee laxity device (Rotameter) with an applied torque of 5, 8 and 10 Nm. The
Pivot‐shift test: Analysis and quantification of knee laxity parameters using a navigation system
Journal of …, 2010
tests are important in the assessment of ACL reconstruction. The goal of this work was to analyze the reliability of the PS test using a navigation system, identifying a set of new quantitative parameters and evaluating their clinical relevance. Eighteen patients that underwent anatomic double-bundle ACL reconstruction were included. The new dynamic parameters were: anteroposterior translation of the medial and lateral compartments and the joint center and internal/external and varus/valgus rotations of the joint. For each parameter we measured the peaks and the areas obtained during the test. Intratester repeatability, comparisons of pre-and postoperative laxities, and correlations between the PS peaks and the corresponding peaks obtained with standard static tests were evaluated. Areas, peaks, and static laxity outcomes were compared, grouping patients according to the preoperative International Knee Documentation Committee (IKDC) score. The PS test was reliable in identifying the surgical reconstruction. Correlation analysis showed good coefficients both for pre-and postoperative values. Patients with IKDC grade ''D'' had larger areas during the PS compared to patients with grade ''C''. Our analysis is helpful for characterizing patient-specific laxity and surgical performance, thus highlighting the clinical relevance of the PS test. ß
The relationship between grading and instrumented measurements of anterior knee joint laxity
Journal of sport rehabilitation, 2008
The relationship between clinical judgments of anterior knee laxity and instrumented measurement of anterior tibial translation is unclear. To examine the relationship between certified athletic trainers'grading of anterior knee laxity and instrumented measurements of anterior tibial translation. Randomized, blinded, clinical assessment. Laboratory. Model patients receiving evaluation of anterior knee laxity. Twelve model patients were evaluated using a MEDmetric KT1000 knee ligament Arthrometer to establish instrumented measurements of anterior translation values at the tibio-femoral joint. Twenty-two certified athletic trainers were provided with operational definitions of potential laxity grades and examined the model patients to make judgments of anterior knee laxity. Correlation between clinical judgments and instrumented measurements of anterior tibial translation. Clinical judgments and instrumented measurements were mutually independent. Anterior tibial translation gradi...
Rotational knee laxity: reliability of a simple measurement device in vivo
BMC Musculoskeletal Disorders, 2008
Background: Double bundle ACL reconstruction has been demonstrated to decrease rotational knee laxity. However, there is no simple, commercially-available device to measure knee rotation. The investigators developed a simple, non-invasive device to measure knee rotation. In conjunction with a rigid boot to rotate the tibia and a force/moment sensor to allow precise determination of torque about the knee, a magnetic tracking system measures the axial rotation of the tibia with respect to the femur. This device has been shown to have acceptable levels of test re-test reliability to measure knee rotation in cadaveric knees.
Annals of Biomedical Engineering, 2001
The recent development of computer-assisted techniques for surgery, anterior cruciate ligament (ACL) reconstruction in particular, provides new ways of improving intraoperative kinematic evaluation and final functional outcome. In this paper we have tried to identify the optimal protocol for ACL evaluation, which can fully exploit the novel capability of electronic sensors and computer elaboration. In this work we statistically compared the main clinical tests that are used for knee evaluation and three different numerical methods for kinematic analysis. Results showed that only passive tests that investigate rotational and anteroposterior stability could discriminate ACL status and that the most effective protocol for computerized evaluation should be based on the Lachman and Drawer test, and forced internal–external rotations at full extension for pigs and 60° , elaborated with the functional method (Martelli et al. Comput. Methods Programs Biomed. 62:77–86, 2000). © 2001 Biomedical Engineering Society. PAC01: 8719St, 8780-y
Journal of Orthopaedic Research, 2005
Roentgen stereophotogrammetric analysis (RSA) can be used to measure changes in anterior-posterior (A-P) knee laxity after anterior cruciate ligament (ACL) reconstruction. Previous measurements of A-P knee laxity using RSA have employed a tibial coordinate system with the origin placed midway between the tips of the tibial-eminences. However, the precision in measuring A-P knee laxity might be improved if the origin was placed on the flexion-extension axis of rotation of the knee. The purpose of this study was to determine whether a center-of-rotation tibial coordinate system with the origin placed midway between the centers of the posterior femoral condyles, which closely approximates the flexion-extension center-of-rotation of the knee, improves the precision in measuring A-P knee laxity compared to the tibial-eminence-based coordinate system. A-P knee laxity was measured using each coordinate system six times in three human cadaveric knees implanted with 0.8-mm diameter tantalum markers. For each laxity measurement, the knee was placed in a custom loading apparatus and biplanar radiographs were obtained while the knee resisted a 44 N posterior shear force and 136 N anterior shear force. A-P knee laxity was determined from the change in position of the tibia, with respect to the femur, resulting from the posterior and anterior shear forces. The precision for each coordinate system was calculated as the pooled standard deviation of A-P knee laxity measurements. The precision of the center-of-rotation coordinate system was 0.33 mm, which was about a factor of 2 better than the 0.62 mm precision of the tibial-eminence coordinate system (p = 0.006). The 0.33 mm precision with the center-of-rotation coordinate system suggests that an observed change of either 0.56 mm (i.e. 1.7 standard deviations) or greater in A-P knee laxity over time is a real change and not due to measurement error when the new tibial coordinate system is used and other factors contributing to variability are controlled as was done in this study. Accordingly, clinicians and researchers should consider the use of this alternate tibial coordinate system when making serial measurements of A-P knee laxity using RSA because the improved precision allows for the observation of smaller differences.
Orthopaedic Journal of Sports Medicine
Background: Various technologies have been developed to quantify the pivot shift, as it is regarded as a key indicator of anterolateral rotatory laxity of the knee. Purpose: To determine the usefulness of a commercially available triaxial accelerometer (Kinematic Rapid Assessment [KiRA]) in numerically quantifying the pivot shift in patients under anesthesia with an anterior cruciate ligament (ACL)–deficient knee. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Both knees of 50 patients (26 male [mean age, 30.4 years], 24 female [mean age, 26.6 years]) under anesthesia were assessed immediately before unilateral ACL reconstruction by an orthopaedic fellow and 1 of 3 experienced knee surgeons. The pivot-shift grade and 2 KiRA outputs (range of acceleration and slope of acceleration change) were compared. Results: The surgeon and fellow recorded the same pivot-shift grade for 45 of 50 patients (90%). Data from the 5 patients with no agreement and 1 patient with ...