Researchers and orthopedic surgical teams evaluating lateral meniscus posterior root tears during anterior cruciate ligament reconstruction have found that pullout repair into the tibial posterolateral tunnel restores postoperative anterior knee stability and promotes favorable meniscal healing at one year.
Knee joint stability relies heavily on the structural integrity of both the anterior cruciate ligament and the menisci. The anterior cruciate ligament plays an essential role in the rotational stability of the knee, while the meniscus also plays an important role in stability. When a lateral meniscus posterior horn root tear occurs alongside an anterior cruciate ligament injury, the joint faces severe biomechanical stress. Among these lesions, injuries to the posterior root of the lateral meniscus have received increasing attention because of their potential impact on knee biomechanics and clinical outcomes. Research has demonstrated that damage here elevates joint contact pressures and changes kinematics, creating a biomechanical profile similar to a subtotal meniscectomy. When performing ACL reconstruction, overlooking or improperly managing these posterior root injuries can consequently jeopardize knee stability and the patient’s functional recovery.
Biomechanics and Tear Morphology in Lateral Meniscus Posterior Root Injuries
The posterior root of the lateral meniscus anchors the tissue to the tibial plateau and maintains vital hoop stresses. Disrupting this attachment creates a biomechanical situation comparable to a subtotal meniscectomy. Two primary morphological patterns commonly characterize these posterior root lesions: avulsion and radial tears. Even though both categories of injury detach the posterior root and impair normal meniscal mechanics, radial tears are widely viewed as causing a more thorough disruption of the circumferential collagen fibers tasked with transmitting hoop stress. As a result, radial tears could theoretically induce more substantial shifts in tibiofemoral contact mechanics and knee rotational stability compared to avulsion injuries. While radial tears typically sever circumferential collagen fibers completely and theoretically alter contact mechanics more severely, clinical outcomes between the two injury subtypes remain closely evaluated during surgical reconstruction. At the same time, it remains uncertain whether these theoretical mechanical distinctions lead to significant clinical differences, because existing data relies primarily on biomechanical research or diverse clinical groups, with very few direct evaluations comparing the two tear types. The effect that tear morphology has on functional recovery and athletic comeback following ACL reconstruction is still poorly recorded.
Suture Techniques Secure Torn Roots During Reconstruction
To address posterior horn root tears during anterior cruciate ligament reconstruction, orthopedic specialists utilize precise arthroscopic repair methods. Suture techniques secure the torn root before fixation inside the knee. Procedures documented in recent clinical series applied suture devices to pass threads through each end of the tear, creating simple stitches that pull the root into position.
Specifically, surgical teams have implemented pullout repair into the tibial posterolateral tunnel, anchoring the meniscal sutures simultaneously with anterior cruciate ligament reconstruction. This technique aligns the repair directly with the anatomical path of the posterolateral tunnel.
Joint Stability Improves One Year After Repair
Clinical assessments following combined reconstruction and root repair demonstrate favorable stabilization of the joint. In patient cohorts evaluated one year postoperatively, postoperative anterior stability was comparable to that in patients without LMPHRT who underwent ACLR alone. Favorable meniscal healing was observed at one year.
Measurements of side-to-side differences in anterior tibial translation reveal significant improvements following the procedure. Patients with LMPHRT repair showed significantly greater ΔSSD than those without repair (p = 0.049).
