Intra-Tester and Inter-Tester Reliability of the Lachmeter When Measuring Knee Joint Laxity

Knee injuries are common among all age groups, and clinical knee examination is essential for the prognosis, follow-up, and rehabilitation process. The Lachmeter is a newly developed digitized modification of the Rolimeter, making it easier and faster for the test personnel to read the test result. In the present study, we aimed to evaluate the intra-tester and inter-tester reliability of the Lachmeter when testing healthy and traumatic knees. 24 healthy participants and a smaller sample of six ACL patients were examined with the Lachmeter by two intermediate testers and re-examined on a second visit within 21 days. All measurements were performed using two different grip techniques: a Lachman grip and an anterior drawer grip. Intra- and inter-tester reliability was evaluated using intra-class correlation coefficient (ICC), standard error of measurement (SEM), smallest detectable change (SDC), Student's paired t-test, and Bland-Altman plots. The results showed in healthy subjects poor to good intra-tester reliability (ICC range: -0.28-0.87, SEM range: 0.33-1.14 mm, and SDC range: 0.91-3.17 mm) and inter-tester reliability (ICC range: 0.41-0.87, SEM range: 0.27-0.67 mm, and SDC range: 0.75-1.87 mm). In ACL patients, intra-tester reliability was moderate to excellent (ICC range: 0.53-0.94, SEM range: 0.14-0.88 mm, and SDC range: 0.38-2.44 mm), with the exception of one measurement (ICC: 0.26 95% CI [-3.43; 0.89]), whereas inter-tester reliability was overall good (ICC range: 0.61-0.89, SEM range: 0.29-0.71 mm, and SDC range: 0.79-1.97 mm). Reliability measures between grip techniques indicated that the Lachman grip was more reliable than the anterior drawer grip. In conclusion, the Lachmeter showed variation between reliability measures, ranging from poor to good in healthy subjects and moderate to excellent in ACL patients. Future studies are needed to validate the Lachmeter against a gold-standard knee laxity assessment.

Quadriceps and hamstring tendon autografts in ACL reconstruction yield comparably good results in a prospective, randomized controlled trial

INTRODUCTION

Comparable data of functional outcomes of anterior cruciate ligament reconstruction using either hamstring- or quadriceps tendon grafts is controversial. This prospective, randomized controlled trial aims to provide data comparing both grafts regarding the functional outcome.

MATERIALS AND METHODS

A two centre trial involving symptomatic patients 18 years of age or older with an anterior cruciate ligament tear was conducted. We randomly assigned 27 patients to quadruple hamstring tendon reconstruction and 24 to quadriceps tendon reconstruction. The patients were evaluated preoperatively, at 3, 6, 12 and 24 months post-surgery. The primary outcome parameter was the side-to-side knee laxity measured with an arthrometer. Secondary outcomes included results in the International Knee Documentation Committee (IKDC) and Lysholm Scores and isokinetic testing of strength in knee extension and flexion.

RESULTS

Forty-four patients (86%) completed the 2-year follow-up. There was significantly improved knee stability at all time intervals with no difference between the two study groups. The manual side-to-side displacement improved by 4.7 ± 3.0 mm in patients with hamstring tendon reconstruction and 5.5 ± 2.9 mm in patients with quadriceps tendon reconstruction. In addition, muscle strength and outcome scores (IKDC and Lysholm Score) did not show any differences between the hamstring tendon group and the quadriceps tendon group. Patients in the hamstring tendon group returned to their pre-injury activity level after 95.2 ± 45.5 days while patients in the quadriceps tendon group needed 82.1 ± 45.6 days.

CONCLUSION

Quadriceps and hamstring tendon autografts yield comparably good results in primary anterior cruciate ligament reconstruction.