scholarly journals Quantifying the differential functional behavior between the medial and lateral meniscus after posterior meniscus root tears

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259678
Author(s):  
Brian E. Walczak ◽  
Kyle Miller ◽  
Michael A. Behun ◽  
Lisa Sienkiewicz ◽  
Heather Hartwig Stokes ◽  
...  

Meniscus tears of the knee are among the most common orthopedic knee injury. Specifically, tears of the posterior root can result in abnormal meniscal extrusion leading to decreased function and progressive osteoarthritis. Despite contemporary surgical treatments of posterior meniscus root tears, there is a low rate of healing and an incidence of residual meniscus extrusion approaching 30%, illustrating an inability to recapitulate native meniscus function. Here, we characterized the differential functional behavior of the medial and lateral meniscus during axial compression load and dynamic knee motion using a cadaveric model. We hypothesized essential differences in extrusion between the medial and lateral meniscus in response to axial compression and knee range of motion. We found no differences in the amount of meniscus extrusion between the medial and lateral meniscus with a competent posterior root (0.338mm vs. 0.235mm; p-value = 0.181). However, posterior root detachment resulted in a consistently increased meniscus extrusion for the medial meniscus compared to the lateral meniscus (2.233mm vs. 0.4705mm; p-value < 0.0001). Moreover, detachment of the posterior root of the medial meniscus resulted in an increase in extrusion at all angles of knee flexion and was most pronounced (4.00mm ± 1.26mm) at 30-degrees of knee flexion. In contrast, the maximum mean extrusion of the lateral meniscus was 1.65mm ± 0.97mm, occurring in full extension. Furthermore, only the medial meniscus extruded during dynamic knee flexion after posterior root detachment. Given the differential functional behaviors between the medial and lateral meniscus, these findings suggest that posterior root repair requires reducing overall meniscus extrusion and recapitulating the native functional responses specific to each meniscus.

2021 ◽  
Vol 9 (10_suppl5) ◽  
pp. 2325967121S0030
Author(s):  
S. Clifton Willimon ◽  
Michael Busch ◽  
Asahi Murata ◽  
Crystal Perkins

Objectives: The medial and lateral menisci function to optimize force transmission across the knee by increasing contact area between the femur and tibia, absorbing shock, and transmitting loads. The anterior and posterior meniscus roots anchor the meniscus to bone. Injuries to the meniscus root attachments result in extrusion of the meniscus, impaired distribution of hoop stresses, and progressive degenerative articular wear. As a result of these deleterious effects, there has been increasing emphasis on repair of meniscus root injuries to restore structure and function. The purpose of this study is to describe meniscus root tears, associated injuries, and minimum 2-year treatment outcomes in a series of pediatric patients. Methods: A single-institution, IRB approved, retrospective review was performed of consecutive pediatric patients less than 19 years of age with a meniscus root tear treated with transosseous root repair over a 4-year period. All patients had minimum 24-month clinical follow-up. Partial root tears treated with partial meniscectomy or irreparable root tears were excluded. All meniscus root tears were classified arthroscopically based on the tear types described by LaPradeADDIN EN.CITE 9. The primary outcomes were revision meniscus surgery and patient reported outcome scores (PROs) (Lysholm, Patient Satisfaction, and Tegner activity). Results: Twenty-one patients, 11 males and 10 females with a mean age of 15 years (range 7 – 18 years), met inclusion criteria. There were 15 lateral meniscus root tears and 6 medial meniscus root tears. The tears occurred in the posterior root in 20 patients (95%). The most common injury pattern was a lateral meniscus posterior root tear (14 patients, 67%). 18 patients (86%) had an associated ligament tear: 13 ACL tears and 5 PCL tears. Two root tears occurred in isolation, and both were the posterior root of the medial meniscus. The majority of meniscus root tears (15 patients, 71%) were root avulsions (type 5). Mean follow-up was 42 months (range 25 – 71 months). Three patients had a second surgery on the affected knee. In two patients, one with revision ACL reconstruction and one treated with chondroplasty of the patella, the meniscus root repair was noted to be well healed. A third patient sustained a new injury to the knee 4 years following medial meniscus posterior root repair and underwent partial medial meniscectomy. At final follow-up, PROs were obtained for 17 patients (81%). Mean Lysholm score was 91 (range 51 – 100). Mean patient satisfaction score was 8.7 (range 5 – 10). Fourteen of 16 patients (88%) reported returning to the same or higher level of activity following surgery. Conclusions: Meniscus root tears occur in pediatric patients, most commonly as root avulsions of the posterior root of the lateral meniscus and in association with ACL tears. This is unique as compared to the adult population, in which the medial meniscus posterior root is often injured in isolation and radial tears adjacent the root are the most commonly described injury pattern. In our case series, transosseous root repair resulted in successful outcomes in the majority of patients with durable results at midterm follow-up.


2021 ◽  
Vol 9 (7_suppl4) ◽  
pp. 2325967121S0020
Author(s):  
Matthew LaPrade ◽  
Mario Hevesi ◽  
Ryan Wilbur ◽  
Bryant Song ◽  
Nicholas Rhodes ◽  
...  

Objectives: Meniscus root tears are increasingly being recognized. Meniscus extrusion has previously been associated with medial root tears; however, the relationship between secondary meniscus restraints, such as the meniscotibial (MT) ligament, extrusion, and root tears has yet to be formally evaluated. The purpose of this study was to better understand the association between MT ligament competence, medial meniscus extrusion, and medial meniscus posterior root tears (MMPRT), as well as to determine the progression of meniscus extrusion over time. Methods: Serial MRI’s from our institution were reviewed for patients who showed evidence of medial meniscus extrusion and MMPRT on at least one of 2+ available MRI’s. All patients were symptomatic at the time of diagnosis. All MRI’s were analyzed independently by two board-certified musculoskeletal radiologists. MT ligament disruption, medial meniscus extrusion, and MMPRT presence was recorded for each MRI. The time between MRI’s, presence of insufficiency fractures, and Outerbridge classification for the medial femur and tibia were also evaluated. Results: 27 knees in 26 patients were included in this study, with a total of 63 MRI’s analyzed (21 knees with 2 MRI’s, 3 with 3 MRI’s, and 3 with 4 MRI’s). All patients demonstrated clear medial meniscus extrusion and meniscotibial ligament disruption prior to the subsequent development of MMPRTs (p < 0.001). Mean extrusion at the time of initial MRI was 3.3 ± 1.1 mm, and increased significantly to 5.5 ± 1.8 mm at the time of first imaging with an identified MMPRT (p < 0.001). The average time between initial MRI and the first identification of MMPRT on a later MRI was 1.7 ± 1.6 years. Conclusions: In a sample of 27 symptomatic knees with serial MRI’s both before and after MMPRT diagnosis, all patients demonstrated MT ligament disruption and associated meniscus extrusion prior to the development of subsequent medial meniscus root tears. These findings suggest that MT ligament disruption and medial meniscus extrusion represent early and predisposing events contributing to MMPRT. Therefore, this provides a possible explanation of why meniscus extrusion is not corrected with medial meniscus root repair.


2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0003
Author(s):  
S. Clifton Willimon ◽  
Melissa Christino ◽  
Michael Busch ◽  
Crystal Perkins

Background: The medial and lateral menisci function to optimize force transmission across the knee by increasing contact area between the femur and tibia, absorbing shock, and transmitting loads. Injuries to the meniscus root attachments result in extrusion of the meniscus, impaired distribution of hoop stresses, and degenerative articular wear. The purpose of this study is to describe meniscus root tears, associated injuries, and treatment in a series of pediatric patients Methods: A single-institution retrospective review was performed of consecutive pediatric patients treated for meniscus root tears from 2013 – 2017. Inclusion criteria were patients less than 19 years of age, arthroscopic evidence of a meniscus root tear, and minimum 6 months clinical follow-up. The primary outcome was surgery for revision of the meniscus repair. Results: Twenty-seven patients were identified to fit inclusion criteria. There were 15 males and 12 females with a mean age of 15.2 years (range 7 – 18 years). Basketball, soccer, and football accounted for the majority (56%) of injuries. The lateral meniscus was involved in 21 patients (78%) and the medial meniscus in 6 patients (22%). The posterior meniscus root was torn in 25 patients (93%) and anterior meniscus root in 2 patients (7%). The most common injury pattern was a lateral meniscus posterior root tear (19 patients, 70%). Associated injuries included an ACL tear (19 patients, 70%), PCL tear (6 patients, 22%), and a tear of the opposite meniscus (7 patients, 26%). Two root tears occurred in isolation, and both were of the posterior root of the medial meniscus. All patients were treated surgically with an arthroscopic transosseous root repair in addition to simultaneous treatment for their associated injuries. Mean follow-up was 14 months (range 6 – 37 months). No patients required additional surgery for their meniscus root tear. Two patients had a second surgery on the affected knee: one for revision ACL reconstruction 2 years following the primary procedure and the other for chondroplasty of the patella 2.5 years following the primary procedure. Conclusions: Meniscus root tears occur in pediatric and adolescent patients, most commonly affecting the posterior root of the lateral meniscus and occurring in association with ACL tears. The adolescent meniscus root injury pattern is unique compared to the adult population in which the medial meniscus posterior root is often injured in isolation. Inspection of the meniscus root attachments with deliberate probing to assess the meniscus roots should be a routine part of every knee arthroscopy. In our case series, transosseous root repair resulted in successful outcomes in all patients without need for any additional meniscus treatment.


2021 ◽  
Author(s):  
Daisuke Chiba ◽  
Tomoyuki Sasaki ◽  
Yasuyuki Ishibashi

Abstract Purpose: To elucidate the association between medial meniscus extrusion measured on ultrasonography (MMEUS) and the prevalence of medial meniscus posterior root tear detected on magnetic resonance imaging (MMPRTMRI). Methods: We recruited 127 patients (135 knees) in this cross-sectional study. All participants had medial knee pain without a knee trauma or surgery history. Knee osteoarthritis (KOA) severity was evaluated using Kellgren-Lawrence grade (KLG) scores. Patients with KLG scores 0-1 and ≥2 were classified in non-radiographic (non-ROA) and radiographic KOA (ROA) groups, respectively. MMEUS was measured with patients in the supine position. Based on T2*-weighted images, MMPRTMRI was defined as the presence of “Ghost meniscus sign” and “Creft/truncation sign”, indicating an abnormal high signal intensity of a disrupted posterior root. MMEUS was compared between MMPRT+ and MMPRT– patients using a non-paired t-test. Receiver operating characteristic (ROC) curves were used to determine the optimal cut-off MMEUS to predict MMPRT+.Results: The prevalence of MMPRT+ was 31.3% (25/80 knees) and 29.1% (16/55 knees) in the non-ROA and ROA groups. The MMEUS of MMPRT+ patients were significantly greater than that of MMPRT– patients in both the non-ROA (5.9±1.4 mm vs. 4.4±1.0 mm, P<0.001) and ROA (7.8±1.3 mm vs. 6.3±1.3 mm, P<0.001) groups. ROC curves demonstrated that 5-mm and 7-mm MMEUS were the optimal cut-off values in non-ROA (adjusted odds ratio: 6.280; area under the curve [AUC]: 0.809; P<0.001) and ROA (adjusted odds ratio: 15.003; AUC: 0.797; P=0.001) groups.Conclusions: In early non-radiographic KOA stages, a greater MMEUS was associated with a higher MMPRTMRI prevalence.Level of evidence: III, Cross-sectional cohort study


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