Comparison of Intercondylar Notch Width Index and Reverse Notch Width Index in Cases With and Without Anterior Cruciate Ligament Tears

摘要

Objective: To compare intercondylar notch width index and reverse notch width index in cases with and without anterior cruciate ligament tears. Patients and methods: 33 patients with a positive lachman’s test and pivot shift and a complete ACL tear on MRI were taken as cases. 33 patients with knee pain but a negative Lachman’s test and pivot shift and no ACL tear on MRI were taken as controls. To obtain the radiographic images of femoral intercondylar notch, the Holmblad (1937)(7) method was used. The Notch width index and the Reverse notch width index was calculated for all the cases and controls from radiographic measurements and the results were compared statistically using Pearson chi square test. Results: The maximum number of cases and controls were in the age group 21-30 years with mean age of 28.61 yrs for cases and 28.91 yrs for controls. Maximum number of cases (69.7%) and controls (75.8%) had NWI greater than 0.25. Maximum number of cases (45.5%) and controls (54.5%) had RNWI less than 4.7 indicating wide notch. Conclusion: No significant relation could be established between Notch width Index and Reverse notch width index with anterior cruciate ligament injury. Introduction Anterior Cruciate Ligament ruptures are among the most common ligamentous injuries.The acute tear of anterior cruciate ligament (A.C.L.) is common in sports requiring frequent rotational movements, rough stops or jumps. It is a belief that the morphology of the femoral intercondylar notch can predispose to the injuries of A.C.L., and its morphometry analysis could provide important data to be used in the prevention and prognostic of these injuries(1). The intercondylar notch can be analyzed by computed tomography (C.T.)(2), by magnetic resonance imaging (M.R.I.), by film radiography and, also by the direct measurement in corpses.The most common and accessible method to assess the femoral intercondylar notch morphology have been radiography(3). Studies using radiographic images have been linking femoral intercondylar notch morphologic and morphometry to A.C.L. injuries (1,3,4,5). Shelbourn and Kerr (4) was the first to correlate the femoral intercondylar notch proportions and A.C.L. injury prediposition. They observed that A.C.L. gets constitutionally a vulnerable position, being retaining over the lateral femoral condyle internal face during knees rotational movements, facilitating its rupture.In the morphometric studies index of notch width (NWI) and index of notch shape (NSI) are commonly used(6).According to Koukoubis et al(3), the most constant index to assess the morphology of the femoral intercondylar notch is considered to be the reverse notch width index(RNWI).Our aim of study was to measure the notch width index and the reverse notch width index in chronic ACL deficient knees and controls and to compare the results and find out the relation between them. Materials And Methods From the patients attending the outpatient department, 33 patients with knee pain with a positive Lachman’s test and pivot shift and a complete ACL tear on MRI were taken as cases. 33 patients with knee pain but a negative Lachman’s test and pivot shift and no ACL tear on MRI were taken as controls. To obtain the radiographic images of femoral intercondylar notch, the Holmblad (1937)(7) method was used. The individuals were positioned on the examination table knees in 70 ° flexion with the hands and knees over the table (Figure 1) and x-rays projected posteroanteriorly.