Comparative analysis of Lachman’s test versus pivot Shift test in diagnosing anterior cruciate ligament tear

Abstract

Background and Aim: The physical examination of the knee is important in diagnosing the cases of ACL tear. The Anterior Drawer test, The Lachmans test and the pivot shift test have gained special recognition and should be performed in cases of unstable knee with suspected ACL injury. It is generally accepted that the Lachmans test has the highest sensitivity and the pivot shift test has the highest specificity. This Study was carried out to find out the sensitivity and specificity of the above mentioned tests and their efficiency in our clinical setting. Patients and Methods: This prospective cohort study was conducted at Govt. Hospital for Bones and Joints surgery, an affiliated Hospital of Government Medical College Srinagar, From June 2020 to December 2022. We included 26 patients of symptomatic ACL tear in the age group of 18-50 years. The knees were physically examined and Lachmans test and Pivot Shift test were performed and findings recorded. The physical examination findings were compared to the Arthroscopic and MRI findings. Sensitivity and specificity were calculated. Statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 21.0. Results: Total 26 patients were evaluated and analysed including 25 males and 1 female. The mean age was 36.5 years. The right knee was affected in 17 (65.30%) patients and the left knee was affected in 9 (34.6%). Mode of injury was sports related in 12 (46.15%), road traffic accident in 9 (34.6%), and fall in 5 (19.23%). The Lachmans test was a sensitive test (88%) as compared to Pivot Shift (60%) in diagnosing ACL tears. We found out the specificity of pivot shift test to be 96% which was quite high as compared to the Lachmans Test 82%. Conclusion: We were able to establish that the Pivot shift test had a high Specificity but a low sensitivity in diagnosing ACL injuries. Both the sensitivity and specificity of Lachman’s test was high, albeit the specificity was less as compared to the Pivot shift test.