Diagnostic Tools for Acute Anterior Cruciate Ligament Injury: GNRB, Lachman Test, and Telos

PURPOSE: The purpose of this study is to compare the accuracy of the GNRB arthrometer (Genourob), Lachman test, and Telos device (GmbH) in acute anterior cruciate ligament (ACL) injuries and to evaluate the accuracy of each diagnostic tool according to the length of time from injury to examination. MATERIALS AND METHODS: From September 2015 to September 2016, 40 cases of complete ACL rupture were reviewed. We divided the time from injury to examination into three periods of 10 days each and analyzed the diagnostic tools according to the time frame. RESULTS: An analysis of the area under the curve (AUC) of a receiver operating characteristic curve showed that all diagnostic tools were fairly informative. The GNRB showed a higher AUC than other diagnostic tools. In 10 cases assessed within 10 days after injury, the GNRB showed statistically significant side-to-side difference in laxity (p<0.001), whereas the Telos test and Lachman test did not show significantly different laxity (p=0.541 and p=0.413, respectively). CONCLUSIONS: All diagnostic values of the GNRB were better than other diagnostic tools in acute ACL injuries. The GNRB was more effective in acute ACL injuries examined within 10 days of injury. The GNRB arthrometer can be a useful diagnostic tool for acute ACL injuries.

Correlation Analysis of KT 2000 arthrometer, Cybex Isokinetic Test and Lysholm Knee Score in ACL deficient knees

PURPOSE: The authors performed correlation analysis among the values of KT 2000 arthrometer, Cybex isokinetic test, and Lysholm knee score to reveal the clinical significance and their role in functional evaluation of ACL insufficiency. MATERIALS AND METHODS: Fifty-one patients with isolated ACL insufficiency were evaluated with KT 2000 arthrometer (15, 20, 30 lb, max.manual), Cybex isokinetic test (60 & 180 degrees/sec), and Lysholm knee score. Correlation analysis was performed between the values of the tests. RESULTS: The Lysholm knee scores had significant linear correlation with the values of KT 2000 of maximal manual difference (r=0.587, P<0.05). The Lysholm knee score had significant linear correlation with all the values of Cybex test of hamstring & quadriceps muscle weakness (r=0.585, 0.635, 0.656, 0.720, p<0.05). The degree of muscle weakness and maximum manual difference in KT 2000 did not show any linear correlation. The time lap between injury and evaluation did not show any correlation with any of the above parameters. CONCLUSION: Lysholm knee score appears to be mostly influenced by the degree of muscle weakness than anterior displacement. The values of KT 2000 of maximal manual difference revealed to be best correlated with Lysholm knee score. The time interval after injury cannot be clinically correlated with muscle weakness or Lysholm knee score.

Reliability of the Manual Maximal Displacement Test and Quadriceps Active Test with KT-1000 TM Arthrometer in the assessment of Posterior Instability of the Knee

Authors measured the degree of posterior instability of the knee in 21 patitients who had posterior cruciate ligament(PCL) injury or have been reconstructed the PCL by using the manual maximal displacement test and quadriceps active test with KT-1000 arthrometer. To compare the reliability between the manual maximal displacement test and the quadriceps active test, two testers participated in the experiment. One tester was a novice and the other tester had substantial clinical experiences with the KT-1000 arthrometer. The quadriceps neutra! Angle was measured in the uninjured knee, and then quadriceps active test was done. Manual maximal displacement test and Quadriceps active test were done by each tester. In manual maximal displacement test, the Pearson correlation coefficient of the uninjured knee between two testers was 0.852 and that of PCL injured knee between two testers was 0.802. In quadriceps achive test, the Pearson correlation coefficient between two testers was 0.173. As a result, the manual maximal displacement test was more reliable for th measurement of the degree of the posterior instability in patients with posterior cruciate ligament tear or reccnstruction.

The Changes of Anterior Displacement in Combined ACL / MCL Injured Knee after MCL Healing / 대한정형외과학회잡지

The medial collateral ligament(MCL) of the knee is the well established secondary restraint to the anterior displacement of the knee joint. However, there has been no report about the estimation of the anterior displacement in combined ACL(anterior collateral ligament) and MCL injures according to period when they were treated with conservative measures. This prospective study evaluated the changes of anterior displacement over time in combined ACL/MCL injury as the MCL injury heals after initial conservative measures. 19 patients who had combined ACL/MCL injury were followed during twelve months after injury. All patient had a positive Lachman test and were evaluated the side to side differences on KT-2000 knee arthrometer(Medmetric, San Diego, California) testing under 20 Ibs anterior tibial loading at 30 degree knee flexion. The stability of the knee was assessed using KT-2000 knee arthrometer every 8 weeks with clinical examination prospectively. They were treated with CI (Combined instability) brace (Smith & Nephew, Carlsbad, California) as conservative measures. Overall, Initial side to side difference of the anterior displacement was averaged 5.21mm (range,4.0-7.0mm) and 3.30mm (range,2.0-5.5mm) finally. According to the classification of MCL injury, in Grade III groups, they had the greatest initial anterior displacement about 6.4mm, but tight- ened the most to 3.08mm finally. In Grade II and Grade I groups they showed 2.97mm and 2.13mm side to side difference (p>0.01). However in Grade I, the anterior displacement were decreased by 4 months after injury but, it were increased at 6 months after injury. In Grade II and III, the decrement of the anterior displacement were continued by 6 months after injury, but they were not changed after that. The data was analyzed by General Linear Model Procedure method. Conclusively, the anterior displacement of knee in patients with combined ACL/MCL injury was diminished with the time in the majority of patients as the MCL healed. It means that the MCL was the stabilizer to the anterior displacement of the knee under the anterior tibial loading.

Diagnosis of Acute Anterior Cruciate Ligament Injuries / 대한정형외과학회잡지

The purposes of this study were to evaluate the diagnostic modalities of the acute rupture of anterior cruciate ligament(ACL) and to know the differences hetween complete and partial ACL rupture preoperatively, analyzing the methods of physical examimation and the clinical features in acutely injured patient. We analyzed the anterior drawer test, Lachman test, KT-2000 arthrometer, MRI findings and associated injuries in the 35 patients who were confirmed to have ACL rupture by arthroscopy of the knee joint, performed within a month after trauma. We divided the patients by arthroscopy into 2 groups: complete rupture group and the partial rupture group. Among the 35 cases of ACL rupture, there were 10 cases of partial rupture and 25 cases of complete rupture. The Lachman s test was the most sensitive method of the physical examinations in detecting acute ACL injuries, with 90% and 92% positive rate in each group retrospectively. KT-2000 arthrometer with more than 3mm side-to-side difference showed all positive findings except one. The findings of ACL rupture in MRI were discontinuity, increased signal intensity, ahnormal course of ACL fibers and so on. The sensitivity of MRI in diagnosing the acute injuries of ACL was 97.2% hut had difficulties in differentiating the complete from partial rupture. Associated injuries of the ACL injured knee were medial and lateral meniscus tear and medial collateral ligament injury. The diagnosis of acute ACL rupture was made possihle hy physical examinations and with use of the KT-2000 arthrometer and MRI was useful in detecting the ACL rupture or associated injuries but not in differentiating complete from partial rupture of the ACL.

Measurement of Posterior Laxity of Normal Knee in Korean Adults by means of KT-2000 Knee Ligament Arthrometer / 대한정형외과학회잡지

We measured normal range and mean value of the posterior laxity of normal knee which might be reference for objective and accurate diagnosis, decision of operative indication and position of knee during fixation of ligament, and role of quadriceps building in posterior cruciate ligament injury patients. These results were obtained by measurement and analysis of posterior laxity of normal knee by means of KT-2000 Knee Ligament Arthrometer. We measured 184 Korean adults (100 males, 84 females), and their average age, height, weight, and thigh circumference were 29.8 years, 165.8cm, 59.8kg, 41.2cm, respectively. At 25 degrees of knee flexion, mean posterior displacement of normal knee was 21.2mm with 15lb posterior tibial loading, 2.41mm with 20lb posterior tibial loading. And when quadriceps were tense, laxity was 0.79mm and 0.95mm at the same degree of knee flexion. At 75 degrees of knee flexion, the results were 0.57mm, 0.58mm, 0.26mm, and 0.28mm respectively. Right to left difference of posterior displacement with 20lb posterior tibial loading was 0.07mm at 25 degrees of knee flexion and 0.06mm at 75 degrees of knee flexion. We thought that above 75 degrees of knee flexion is suitable for knee position at the time of graft fixation because 75 degrees of knee flexion markedly decreased(75%) posterior displacement compare to 25 degrees of knee flexion. When quadriceps were tense, remarkable decrease of posterior laxity of normal knee was checked(58%), so we noticed quadriceps building is important to management of posterior cruciate ligament injury patients.

The Passive Drawer Measurement of Anterior Knee Laxity by using K / 대한정형외과학회잡지

The rupture of anterior cruciate ligament has been diagnosed by stress test, radiogram and diagnostic arthroscopy, but these methods have several disadvantages of lack of objectivity, exposure to radiation and risk of anesthesia. To eliminate these difficulties, the K-T 1,000 knee ligament arthrometer was used for the objective diagnosis in the injury of anterior cruciate ligament. We performed instrumented measurement of anterior-posterior laxity of the knee in 100 normal subjects by using the K-T 1,000 knee ligament arthrometer under the 15 lb., 20 lb. and maximum anterior pulls, and 20 lb. posterior push. The following results were obtained: 1. The mean anterior displacement at 20 lb.: 4.43mm The mean posterior displacement at 20 lb.: 2.30mm 2. The mean right knee-left knee difference in anterior displacement: 0.89mm 3. The mean anterior compliance index: 1.16mm So, we believed that a right knee-left knee difference and a anterior compliance index are sensitive measures of the integrity of the anterior cruclate ligament. And this test method was helpful for the diagnosis and objective recording in the injury of anterior cruciate ligament. This test method has following advantages: 1. There is no anesthesia risk. 2. The patient and examiner undergo no radiation exposure. 3. Diagnostic arthroscopy may be avoided. 4. Due to patient comfort, there is minimal muscle guarding.