Repair of Lateral Meniscus Posterior Horn Detachment Lesions A Biomechanical Evaluation
Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, New York.The American Journal of Sports Medicine (Impact Factor: 4.36). 09/2012; 40(11). DOI: 10.1177/0363546512458574
BACKGROUND:Posterior horn detachment (PHD) lesions of the lateral meniscus are commonly associated with acute anterior cruciate ligament (ACL) tears. Multiple surgeons have advocated for repair of this lesion at the time of ACL reconstruction. However, the biomechanical consequences of this lesion and its subsequent repair have not been evaluated. HYPOTHESIS:The PHD lesion of the lateral meniscus will lead to increased tibiofemoral contact pressures, and repair of this lesion to bone via a tibial tunnel can restore normal contact pressures during simulated gait. STUDY DESIGN:Controlled laboratory study. METHODS:Lateral compartment contact pressures were measured via a sensor on the tibial plateau in 8 cadaver knees with the knee intact, after sectioning the posterior horn of the lateral meniscus to simulate PHD, and after repairing the injury. The repair was performed using an ACL tunnel guide to drill a tunnel from the anteromedial tibia to the posterior horn attachment site. Dynamic pressure data were continuously collected using a conductive ink pressure sensing system while each knee was moved through a physiological gait flexion cycle. RESULTS:Posterior horn detachment caused a significant increase in tibiofemoral peak contact pressure from 2.8 MPa to 4.2 MPa (P = .03). After repair of the lesion to bone was performed through a transtibial tunnel, the peak contact pressure was 2.9 MPa. Posterior horn detachment also significantly decreased the maximum contact area over which tibiofemoral pressure is distributed from 451 mm(2) in the intact state to 304 mm(2) in the detached state. Repair of the PHD lesion increased the maximum contact area to 386 mm(2), however, this area was also significantly less than in the intact state (P = .05). CONCLUSION:Posterior horn detachment of the lateral meniscus causes increased peak tibiofemoral contact pressure. The peak pressure can be reduced to a normal level with repair of the lesion to bone via a transtibial tunnel. CLINICAL RELEVANCE:Posterior horn detachment of the lateral meniscus is a lesion often associated with an acute ACL tear. Debate exists concerning the importance of repairing PHD lesions at the time of ACL reconstruction. The data provided in this study may influence surgeons' management of the lesion.
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- "Treatment for PLMRTs is controversial, and the advantages of root repair over non-surgical treatment are currently unknown[2,6,57]. However, biomechanical studies have shown that root repair can restore knee biomechanics to normal levels[3,43,55]. We therefore believe that repair of the PLMR should be attempted whenever possible in order to restore the hoop tension of the lateral meniscus and to prevent premature osteoarthritis , especially in the case of an absent MFL[8,20]. "
ABSTRACT: To summarize and discuss the current knowledge on posterior lateral meniscus root tears. A comprehensive review of the MEDLINE database was carried out to identify relevant articles using different keywords (e.g. "meniscus root", "root tear", "meniscus avulsion", "radial tear" and "lateral meniscus"). The reference lists of the reviewed articles were searched for additional relevant articles. Posterior lateral meniscus root tears are found in 7-12 % of patients with a tear of the anterior cruciate ligament (ACL). Biomechanical studies have found an increase in lateral compartment contact pressure of approximately 50 % after creation of a posterior lateral meniscus root tear. There is some evidence that the biomechanical consequences of these injuries are significantly influenced by the presence and integrity of the meniscofemoral ligaments. Clinical studies have found encouraging results after repair of posterior lateral meniscus root tears. Whether root repair can prevent the development of osteoarthritis is currently unknown. A posterior lateral meniscus root tear is a clinical relevant but most likely underrecognized concomitant injury in patients with a tear of the ACL. This article may support clinicians in diagnosing and treating this unique type of meniscus tear. LEVEL OF EVIDENCE: V.
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- "In practice, the attachment is more anterior than one might expect, and if no low-signal structure can be seen directly attaching to bone, a tear is likely present (Fig. 8). A meniscal detachment in this location is important to detect because it renders the entire lateral meniscus unstable and substantially increases tibial loading, which could predispose to early osteoarthritis . "
ABSTRACT: ObjectiveMagnetic resonance imaging (MRI) findings in anterior cruciate ligament (ACL) injury are well known, but most published reviews show obvious examples of associated injuries and give little focus to paediatric patients. Here, we demonstrate the spectrum of MRI appearances at common sites of associated injury in adolescents with ACL tears, emphasising age-specific issues.MethodsPictorial review using images from children with surgically confirmed ACL tears after athletic injury.ResultsACL injury usually occurs with axial rotation in the valgus near full extension. The MRI findings can be obvious and important to management (ACL rupture), subtle but clinically important (lateral meniscus posterior attachment avulsion), obvious and unimportant to management (femoral condyle impaction injury), or subtle and possibly important (medial meniscocapsular junction tear). Paediatric-specific issues of note include tibial spine avulsion, normal difficulty visualising a thin ACL and posterolateral corner structures, and differentiation between incompletely closed physis and impaction fracture.ConclusionACL tear is only the most obvious sign of a complex injury involving multiple structures. Awareness of the spectrum of secondary findings illustrated here and the features distinguishing them from normal variation can aid in accurate assessment of ACL tears and related injuries, enabling effective treatment planning and assessment of prognosis.Teaching points• The ACL in children normally appears thin or attenuated, while thickening and oedema suggest tear.• Displaced medial meniscal tears are significantly more common later post-injury than immediately.• The meniscofemoral ligaments merge with the posterior lateral meniscus, complicating tear assessment.• Tibial plateau impaction fractures can be difficult to distinguish from a partially closed physis.• Axial MR sequences are more sensitive/specific than coronal for diagnosis of medial collateral ligament (MCL) injury.
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- "Tears of the posterior root attachments of both menisci lead to significantly increased load in the respective compartments due to loss of hoop containment.3,34 Significantly increased compartment loads result in early osteoarthritis due to the resultant load transfer on the articular cartilage.16,18 "
ABSTRACT: Context:Magnetic resonance imaging (MRI) affords high-resolution visualization of the soft tissue structures (menisci, ligaments, cartilage, etc) and bone marrow of the knee.Evidence Acquisition:Pertinent clinical and research articles in the orthopaedic and radiology literature over the past 30 years using PubMed.Results:Ligament tears can be accurately assessed with MRI, but distinguishing partial tears from ruptures of the anterior cruciate ligament (ACL) can be challenging. Determining the extent of a partial tear is often extremely difficult to accurately assess. The status of the posterolateral corner structures, menisci, and cartilage can be accurately evaluated, although limitations in the evaluation of certain structures exist. Patellofemoral joint, marrow, tibiofibular joint, and synovial pathology can supplement physical examination findings and provide definitive diagnosis.Conclusions:MRI provides an accurate noninvasive assessment of knee pathology.
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