Guan-Yang Song1, Xin Liu1, Hui Zhang1, Qian-Qian Wang2, Jin Zhang1, Yue Li1, Hua Feng3. 1. Sports Medicine Service, Beijing Jishuitan Hospital, Beijing, China. 2. Clinical Research & Evidence-based Medicine Center, Beijing Institute of Traumatology & Orthopaedics, Beijing Jishuitan Hospital, Beijing, China. 3. Sports Medicine Service, Beijing Jishuitan Hospital, Beijing, China fenghua20080617@126.com.
Abstract
BACKGROUND: A special type of meniscal lesion involving the peripheral attachment of the posterior horn of the medial meniscus (PHMM), termed ramp lesion, is commonly associated with anterior cruciate ligament (ACL) injury. However, no study has investigated its anatomic risk factors. Recently, increased meniscal slope has been identified as an independent anatomic risk factor for noncontact ACL injury. HYPOTHESIS: Increased medial meniscal slope (MMS) as measured on magnetic resonance imaging (MRI) will correlate with greater risk of concomitant ramp lesion in noncontact ACL injury. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: From January 2011 to December 2013, a total of 1012 consecutive patients were diagnosed as having noncontact ACL injuries and underwent primary ACL reconstructions. Among them, 160 patients were arthroscopically verified to have concomitant ramp lesions. Study exclusion criteria included partial ACL rupture, multiligamentous injury, associated medial/lateral meniscal lesions other than ramp lesion, skeletal immaturity, general joint laxity, severe malalignment of the lower extremity, history of knee surgery, lack of available preoperative MRI, and history of trauma to the proximal tibia. This left 53 patients in the study group (ACL + ramp group), who were matched in a 1:1 fashion to 53 control participants (isolated ACL group) who were arthroscopically verified to have isolated complete ACL injury during the same study period. Patients were matched by age, sex, and time from injury to surgery (TFI). Patients from the matched control group were selected by applying the same exclusion criteria as mentioned above. The MMS and medial posterior tibial slope (MPTS) were measured on the preoperative MRI in a blinded fashion. Predictors of ramp lesion, including MMS, MPTS, body mass index, pivot-shift test grade, and KT-1000 arthrometer side-to-side difference, were assessed by multivariable conditional logistic regression analysis. RESULTS: The mean MMS in the study group was 3.5°, which was significantly larger than that in the control group (2.0°; P < .001). In addition, increased MMS was significantly (odds ratio [OR], 5.180; 95% CI, 1.814-32.957; P < .001) associated with concomitant ramp lesion in noncontact ACL injury, especially for those with a TFI of ≥6 months (OR, 13.819; 95% CI, 2.251-49.585; P < .001). However, no significant association was identified between MPTS and concomitant ramp lesion. CONCLUSION: Increased MMS was identified to be an independent anatomic risk factor of concomitant ramp lesions in noncontact ACL injuries, particularly for those with a TFI ≥6 months. This may provide additional information for counseling patients who have increased MMS on the greater risk of secondary PHMM lesions if their ACL-deficient knee joints are not well stabilized initially.
BACKGROUND: A special type of meniscal lesion involving the peripheral attachment of the posterior horn of the medial meniscus (PHMM), termed ramp lesion, is commonly associated with anterior cruciate ligament (ACL) injury. However, no study has investigated its anatomic risk factors. Recently, increased meniscal slope has been identified as an independent anatomic risk factor for noncontact ACL injury. HYPOTHESIS: Increased medial meniscal slope (MMS) as measured on magnetic resonance imaging (MRI) will correlate with greater risk of concomitant ramp lesion in noncontact ACL injury. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: From January 2011 to December 2013, a total of 1012 consecutive patients were diagnosed as having noncontact ACL injuries and underwent primary ACL reconstructions. Among them, 160 patients were arthroscopically verified to have concomitant ramp lesions. Study exclusion criteria included partial ACL rupture, multiligamentous injury, associated medial/lateral meniscal lesions other than ramp lesion, skeletal immaturity, general joint laxity, severe malalignment of the lower extremity, history of knee surgery, lack of available preoperative MRI, and history of trauma to the proximal tibia. This left 53 patients in the study group (ACL + ramp group), who were matched in a 1:1 fashion to 53 control participants (isolated ACL group) who were arthroscopically verified to have isolated complete ACL injury during the same study period. Patients were matched by age, sex, and time from injury to surgery (TFI). Patients from the matched control group were selected by applying the same exclusion criteria as mentioned above. The MMS and medial posterior tibial slope (MPTS) were measured on the preoperative MRI in a blinded fashion. Predictors of ramp lesion, including MMS, MPTS, body mass index, pivot-shift test grade, and KT-1000 arthrometer side-to-side difference, were assessed by multivariable conditional logistic regression analysis. RESULTS: The mean MMS in the study group was 3.5°, which was significantly larger than that in the control group (2.0°; P < .001). In addition, increased MMS was significantly (odds ratio [OR], 5.180; 95% CI, 1.814-32.957; P < .001) associated with concomitant ramp lesion in noncontact ACL injury, especially for those with a TFI of ≥6 months (OR, 13.819; 95% CI, 2.251-49.585; P < .001). However, no significant association was identified between MPTS and concomitant ramp lesion. CONCLUSION: Increased MMS was identified to be an independent anatomic risk factor of concomitant ramp lesions in noncontact ACL injuries, particularly for those with a TFI ≥6 months. This may provide additional information for counseling patients who have increased MMS on the greater risk of secondary PHMM lesions if their ACL-deficient knee joints are not well stabilized initially.
Authors: Dylan N Greif; Michael G Baraga; Michael G Rizzo; Neil V Mohile; Flavio D Silva; Terry Fox; Jean Jose Journal: Skeletal Radiol Date: 2020-01-25 Impact factor: 2.199