Increased Posterior Tibial Slope Results In Increased Incidence Of Posterior Lateral Meniscal Root Tears in ACL Reconstruction Patients

Authors:

David Bernholt, Nicholas N. DePhillipo, Zachary S. Aman, Brian T. Samuelsen, Mitchell I. Kennedy, Robert F. LaPrade

Abstract:

Purpose

While the association with acute anterior cruciate ligament (ACL) tears has been established, other risk factors and associated pathologies which occur with a concomitant lateral meniscal posterior root tear (LMPRT) are not well defined. The purpose of this study was to compare the risk factors and concomitant pathologies between patients with LMPRT and patients without LMPRTs in the setting of a primary ACL tear.

Methods

Patients with a LMPRT identified at the time of primary ACL reconstruction by a single surgeon were identified. These patients were matched by age and sex to patients undergoing primary ACL reconstruction who were not found to have lateral meniscus root tears (control group) in a 1:1 ratio. Lateral posterior tibial slope (PTS), medial PTS, lateral femoral condyle height and depth, lateral tibial plateau depth, and lateral tibial plateau subluxation were measured on MRI. Anteroposterior full-limb alignment radiographs were used to measure the medial proximal tibia angle (MPTA), the mechanical lateral distal femoral angle (mLDFA), and the mechanical weightbearing axis for the injured extremity.

Results

One-hundred three patients were included in both the LMPRT group and the matched control group. Patients with a LMPRT had a significantly steeper lateral PTS (9.1° vs. 7.0°, p = 0.001), a steeper medial PTS (7.0° vs. 6.0°, p = 0.03), and a greater lateral-to-medial slope asymmetry (2.0° vs. 1.0°, p = 0.001). There were no differences in lateral femoral condyle depth or height, lateral tibial plateau depth, lateral tibial plateau subluxation, MPTA, mLDFA, or mechanical weightbearing axis between groups. There was a significantly increased incidence of medial meniscus ramp lesions in patients with lateral meniscus posterior root tears compared with controls (34.0% vs. 15.5%, odds ratio: 2.8, p = 0.002). There were no associations with concomitant ligament injuries, medial meniscus root tears, or non-ramp tears based on case/control grouping.

Conclusion

In conclusion, LMPRTs in the setting of primary ACL injuries were associated with significantly increased lateral and medial PTSs, and increased asymmetry between lateral and medial PTSs. In addition, clinicians should be aware of the increased incidence of concurrent medial meniscal ramp lesions in patients with LMPRTs. Knowledge of these associations helps guide clinical decision-making and counselling of patients in the setting of ACL tears with concomitant LMPRTs.

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Robert LaPrade, MD PhD

Average rating:

26 reviews

Sue Stanek

Jan 2, 2020

by Sue Stanek on Robert LaPrade, MD PhD

So glad I waited for the best

I struggled with my knee for 18 months - having gone from 10,000 steps a day to only walking as needed. Previous attempts to make it better provided only temporary relief. (including injections and arthroscopic surgery), I heard Dr. La Prade was going to practice in the Twin Cities - where I live, & waited for him, based on his renown reputation. I am so glad I did! Dr LaPrade performed a deep root repair to my meniscus, which saved me from a knee replacement at this time. I am 5-months post surgery, and am doing great, stationary biking and exercising every day, no pain.
You know you are seeing the best when you find out he has written over 500 medical journal articles - among many other accomplishments. Hey - if he is good enough for Olympic and professional athletes…..he's good enough for me! Thank you, Dr. LaPrade, for treating me with the care, focus, and expertise as if I was an Olympic athlete!
- From your 63 year old very appreciative patent ~

Nancy S Stevenson

Aug 14, 2019

by Nancy S Stevenson on Robert LaPrade, MD PhD

Right Knee Surgery After Auto Bicycle Accident

Dr. Robert F. LaPrade operated on my right knee in May of 2010. I was hit by a car on my bicycle near Horsetooth Reservoir in CO. I was life flighted to MCR in Loveland, CO. My orthopedic injuries were severe, but totally missesd by the orthopedic team at Poudre. I could not bear weight on my right side though I tried repeatedly, but finally I went and got an MRI and one of the orthopedic surgeons that I worked with was shocked when he saw the MRI result. My right knee was totally destroyed; ACL, MCL, PCL all severely torn; the patella was the only thing intact in my right knee. Dr. La Prade had just moved to Vail and I was his 2nd patient @ The Steadman Clinic. I was told by one of the orthopedic surgeons that I worked with that I would never run again and would be lucky if I could ever hike again. This was devastating news after being a top triathlete (3rd in the world in my age group in 1989 & 1st nationally in my age group) and a big marathon runner. All I can say is Dr. La Prade did an amazing job and I am not limited in any of my activites. I can run, bike, & climb mountains. In fact 2 years ago I finished climbing the top 100 peaks in CO.

Jordan

Aug 2, 2019

by Jordan on Robert LaPrade, MD PhD

Very helpful

I have looked many times for answers on my tibial tubercle osteotomy and never found any as detailed as i needed. This answers all my questions!

Increased Posterior Tibial Slope Results in Increased Incidence of Posterior Lateral Meniscal Root Tears in ACL Reconstruction Patients