1. IRIA - 1112

2. Aim To compare intercondylar notch width in male patients with and without anterior cruciate ligament tear.

3. Materials and Methods 120 male patients, who were referred to the Department of Radiology from December 2013 to October 2014 were included in the study. We included only male patients as there is significant morphometric difference in the bones between male and female patients. Axial, coronal and sagittal magnetic resonance imaging was performed using Hitachi Aperto machine with the patient's knee in extended position.

4. 54 patients with normal anterior cruciate ligament were used as control and 66 patients with a complete or incomplete tear of anterior cruciate ligament were chosen as case group. Only male patients within the age range of 17 to 55 years were included in the study and patients with osteoarthritic changes were excluded. In all patients, the femoral notch width and the bicondylar width were measured on axial images at the level of the popliteal groove. The notch width index was then calculated.

5. Sagittal and axial magnetic resonance images showing normal anterior cruciate ligament in a 21 year old male patient with notch width index of 0.312. ab

6. Sagittal and axial images in a 47 year old male patient showing anterior cruciate ligament tear with narrow intercondylar notch and notch width index of 0.251. a b

7. Sagittal and axial images in a 31 year old male patient showing complete tear of the anterior cruciate ligament with narrow intercondylar notch and notch width index of 0.259. a b

9. Results The 120 patients who were included in the study were between the age 17 to 55 years. The mean notch width index in male patients with anterior cruciate ligament injury (0.261) was lesser in comparison to the patients with no anterior cruciate ligament injury (0.296). The P value was found to be less than 0.05 using Student’s T test.

10. Discussion The anterior cruciate ligament (ACL), one of the major intracapsular knee ligaments, is located in the intercondylar notch of femur. Cranially it is attached to the postero-medial surface of the lateral femoral condyle and caudally to the anterior part of the intercondylar region of the tibia. Injuries to the knee joint are fairly common and the anterior cruciate ligament is the most frequently injured knee ligament. Anterior cruciate ligament injuries can lead to significant morbidity.

11. Numerous procedures have been devised to treat anterior cruciate ligament tears. However, there is no ideal replacement for a normal anterior cruciate ligament. It has been hypothesized that a narrow intercondylar notch predisposes to anterior cruciate ligament injury. Palmer et al, Anderson et al, LaPrade and Burnett, Ireland et al, Shelbourne et al, Lund-Hanssen et al, Souryal et al and more have conducted many studies that concluded that femoral notch stenosis is associated with increased incidence of anterior cruciate ligament tears.

12. Our study also found similar results. The notch width index in male patients with anterior cruciate ligament tear was comparatively smaller than the patients without tear. This suggests that the size of the notch width can be a predictor in assessing the risk factor for anterior cruciate ligament injury.

13. Conclusions In conclusion, we postulate that a smaller notch width index is associated with the risk of anterior cruciate ligament rupture. Magnetic resonance imaging measurement was proven to be effective, and radiologists need to be more cautious when observing and diagnosing patients with small notch width and notch width index.

14. References 1. Domzalski M, Grzelak P, Gabos P. Risk factors for anterior cruciate ligament injury in skeletally immature patients: analysis of intercondylar notch width using magnetic resonance imaging. Int Orthop 2010; 34:703–707. 2. Palmer I. On the injuries to the ligaments of the knee joint. A clinical study. Acta Chir Scand Suppl 1938; 53:1–28. 3. Lund-Hanssen H, Gannon J, Engebresten L, et al. Intercondylar notch width and the risk for anterior cruciate ligament rupture. A case–control study in 46 female handball players. Acta Orthop Scand 1994; 65:529–532. 4. LaPrade RF, Burnett QM 2nd. Femoral intercondylar notch stenosis and correlation to anterior cruciate ligament injuries. A prospective study. Am J Sports Med 1994; 22:198–202, discussion 203. 5. Shelbourne KD, Davis TJ, Klootwyk TE. The relationship between intercondylar notch width of the femur and the incidence of anterior cruciate ligament tears. A prospective study. Am J Sports Med 1998; 26:402–408.

15. 6. Shelbourne KD, Facibene WA, Hunt JJ. Radiographic and intraoperative intercondylar notch width measurements in men and women with unilateral and bilateral anterior cruciate ligament tears. Knee Surg Sports Traumatol Arthrosc 1997; 5:229–233. 7. Souryal TO, Freeman TR. Intercondylar notch size and anterior cruciate ligament injuries in athletes. A prospective study. Am J Sports Med 1993; 21:535–539, Erratum in: Am J Sports Med 1993; 21:723. 8. Uhorchak JM, Scoville CR, Williams GN, et al. Risk factors associated with noncontact injury of the anterior cruciate ligament: a prospective four-year evaluation of 859 West Point cadets. Am J Sports Med 2003; 31:831–842. 9. Herzog RJ, Silliman JF, Hutton K, et al. Measurements of the intercondylar notch by plain fi lm radiography and magnetic resonance imaging. Am J Sports Med 1994; 22:204–210. 10. Lombardo S, Sethi PM, Starkey C. Intercondylar notch stenosis is not a risk factor for anterior cruciate ligament tears in professional male basketball players: an 11-year prospective study. Am J Sports Med 2005; 33:29–34. 11. Schickendantz MS, Weiker GG. The predictive value of radiographs in the evaluation of unilateral and bilateral anterior cruciate ligament injuries. Am J Sports Med 1993; 21:110–113.