Association between intercondylar notch narrowing and bilateral anterior cruciate ligament injuries in athletes.
BACKGROUND
Intercondylar notch narrowing is a risk factor for anterior cruciate ligament (ACL) injuries, but it is unclear whether a narrow intercondylar notch correlates with bilateral ACL injuries.


OBJECTIVE
To determine whether a narrow intercondylar notch is associated with bilateral ACL knee injuries in athletes, using magnetic resonance imaging (MRI) and radiography to investigate the notch size.


METHODS
A retrospective case-control study.


METHODS
This was a comparative cohort study on 50 subjects of which 25 patients with sport trauma-associated bilateral ACL injuries, 30 with unilateral ACL injuries, and 20 healthy subjects. The notch width index (NWI) was measured as the ratio of the width of the intercondylar notch to the femoral condylar width on radiography and the MRI slice containing the region near the ACL attachment site on the femoral side (NWI-A) and on the following posterior slice (NWI-P).


RESULTS
The mean NWI values on radiography were 0.257 (SD 0.040), 0.332 (SD 0.036), and 0.341 (SD 0.027) in the bilateral, unilateral, and control groups, respectively, with significant differences between the bilateral and unilateral groups and the bilateral and healthy groups. On MRI, the mean NWI-A values were 0.236 (SD 0.025), 0.243 (SD 0.048), and 0.266 (SD 0.030), respectively, with a significant difference between the bilateral and healthy groups. The mean NWI-P values were 0.239 (SD 0.021), 0.258 (SD 0.038), and 0.273 (SD 0.033), respectively, with significant differences between the bilateral and unilateral groups and the unilateral and healthy groups. A cutoff value of 0.25 for NWI-P gave an odds ratio of 22.667 for the risk of developing bilateral ACL knee injuries.


CONCLUSIONS
The intercondylar notch was significantly narrower in subjects with bilateral ACL injuries than in healthy subjects. NWI measurement using coronal MRI is useful for judging intercondylar notch narrowing. The risk for ACL injuries is very high when NWI is ≤0.25. Preventive measures for the unaffected knee are required for patients with a narrow intercondylar notch.
Department of Orthopaedic Surgery, Nihon University, School of medicine, 30-1, Ohyaguchi-kamimachi, Itabashi-ku, Tokyo, 173-8610, Japan.
Koh
K
Hoteya
Yuki
Y
Kato
Sayaka
S
Motojima
Sheila J
SJ
Ingham
Takashi
T
Horaguchi
Akiyoshi
A
Saito
Yasuaki
Y
Tokuhashi
D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D001265:Athletic Injuries / Q000209:etiology / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000209:etiology / Q000473:pathology*; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors