Aim: The accuracy of joint line tenderness (JLT) and magnetic resonance imaging (MRI) were determined in the diagnosis of meniscal tears in patients with complete rupture of the anterior cruciate ligament (ACL). Additionally, the effects of time from injury (to arthroscopy) and medial femoral condyle (MFC) lesions on diagnosis with JTL and MRI were established.
Methods: A total of 133 male patients, whose first arthroscopy was performed by MU, were included. Preoperative MRI findings, the initial knee trauma causing ACL rupture, and the time from injury (TFI) were recorded. Physical examinations including JLT were performed within 1 week preceding the operation by the same observer. MRIs were performed within 6 weeks preoperatively by a 1.5 T imager. The first 6 week period after the initial trauma was defined as the acute (Grup I), 6 weeks to 12 months as the subchronic (Grup II) and 12 months or longer as the chronic period (Grup III). The sensitivity, specificity, and accuracy for JLT and MRI were calculated. Retrospective analyses were performed for TFI. Chi-square and kappa (k) tests were used for statistical analyses.
Results: In all patients, mean TFI was calculated as 14.8±16.8 months (median; 8.0). Patient distribution were as follows; 29(21.8%) were Group I, 51(38.3%) Group II, and 53(39.8%) Group III. The sensitivity, specificity, and accuracy of MRI were 89.1%, 87.0%, and 87.9% for MML (p=0.0001,k=0.76), while 91.6%, 74.6%, and 82.7% for LML (p=0.0001,k=0.66), respectively. The sensitivity, specificity, and accuracy of JLT independent from TFI were 66.2%, 76.8%, and 70.7% for MML (p=0.0001,k=0.42), while 59.4%, 67.2%, and 63.2% for LML (p=0.002,k=0.27), respectively. For MML, the accuracy values of Groups I and III were; 86.2% (k=0.72) and 88.7% (k=0.76) for MRI (p=0.0001) and 55.2% (p=0.363, k=0.13) and 77.4% (p=0.0001,k=0.51) for JLT, respectively. For LML these were 75.9% (p=0.007,k=0.51,) and 90.6% (p=0.0001,k=0.81) for MRI and 48.3% (p=0.604,k=0.02) and 71.7% (p=0.002,k=0.43) for JLT, respectively. In Group III, diagnostic accuracy of JLT for MML was 80.0% (p=0.003,k=0.57) in the absence of MFC lesions and decreased to 73.9% (p=0.035,k=0.44) in their presence. In chronic MML, rate of false positive results of JLT in the presence and absence of MFC lesions was 21.7% and 10.0%, respectively (p=0.237).
Conclusion: The accuracy of MRI and JLT in LML was lower than MML, especially in the acute period. In the diagnosis of acute and subchronic LML, and acute MML, use of JTL was not statistically significant. However, in determination of MML, the presence of MFC lesions particularly in the chronic period, lead to a 2-fold increase in the rate of false positive results in terms of diagnosis with JTL.
