Stifle extension results in differential tensile forces developing between abaxial and axial components of the cranial meniscotibial ligament of the equine medial meniscus: A mechanistic explanation for meniscal tear patterns

2011 ◽  
Vol 44 (5) ◽  
pp. 554-558 ◽  
Author(s):  
J. G. FOWLIE ◽  
S. P. ARNOCZKY ◽  
M. LAVAGNINO ◽  
J. A. STICK
2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0010
Author(s):  
Brett Heldt ◽  
Elsayed Attia ◽  
Raymond Guo ◽  
Indranil Kushare ◽  
Theodore Shybut

Background: Acute anterior cruciate ligament(ACL) rupture is associated with a significant incidence of concomitant meniscal and chondral injuries. However, to our knowledge, the incidence of these concomitant injuries in skeletally immature(SI) versus skeletally mature(SM) patients has not been directly compared. SI patients are a unique subset of ACL patients because surgical considerations are different, and subsequent re-tear rates are high. However, it is unclear if the rates and types of meniscal and chondral injuries differ. Purpose: The purpose of this study is to compare associated meniscal and chondral injury patterns between SI and SM patients under age 21, treated with ACL reconstruction for an acute ACL tear. We hypothesized that no significant differences would be seen. Methods: We performed a single-center retrospective review of primary ACL reconstructions performed from January 2012 to April 2020. Patients were stratified by skeletal maturity status based on a review of records and imaging. Demographic data was recorded, including age, sex, and BMI. Associated intra-articular meniscal injury, including laterality, location, configuration, and treatment were determined. Articular cartilage injury location, grade, and treatments were determined. Revision rates, non-ACL reoperation rates, and time to surgery were also compared between the two groups. Results: 785 SM and 208 SI patients met inclusion criteria. Mean BMI and mean age were significantly different between groups. Meniscal tear rates were significantly greater in SM versus SI patients in medial meniscus tears(P<.001), medial posterior horn tears(P=.001), medial longitudinal tears configuration(P=.007), lateral Radial configuration(P=.002), and lateral complex tears(P=.011). Medial repairs(P<.001) and lateral partial meniscectomies(P=.004) were more likely in the SM group. There was a significantly greater number of chondral injuries in the SM versus SI groups in the Lateral(p=.007) and medial compartments(P<.001). SM patients had a significantly increased number of outerbridge grade 1 and 2 in the Lateral(P<.001) and Medial Compartments(P=.013). ACL revisions(P=.019) and Non-ACL reoperations(P=.002) were significantly greater in the SI patients compared to SM. No other significant differences were noted. Conclusion: SM ACL injured patients have a significantly higher rate of medial meniscus tears and medial longitudinal configurations treated with repair, and a significantly higher rate of radial and/or complex lateral meniscus tears treated with partial meniscectomy compared to the SI group. We also found a significantly higher rate of both medial and lateral compartment chondral injuries, mainly grades 1 and 2, in SM compared to SI patients. Conversely, SI ACL reconstruction patients had higher revision and subsequent non-ACL surgery rates.


2018 ◽  
Vol 43 (2) ◽  
pp. 132-139 ◽  
Author(s):  
Mayank Kalra ◽  
Ryan Bakker ◽  
Sebastian S Tomescu ◽  
Anna M Polak ◽  
Micah Nicholls ◽  
...  

Background: A medial meniscal tear is a common knee injury, especially following an anterior cruciate ligament injury. Decreasing the compressive force on the medial meniscus during dynamic activities using an unloader knee brace could reduce meniscal strain, effectively reducing injury risk and/or severity. Objectives: To investigate the efficacy of two unloader knee braces on medial meniscus strain during dynamic activities in intact & deficient anterior cruciate ligament states. Study design: Combined in vivo/in vitro study. Methods: In vivo knee kinematics and muscle force profiles from a healthy individual performing single/doubleleg squats and walking motions were simulated on 10 cadaveric specimens using a dynamic knee simulator system. Simulations were performed on knees in unbraced and braced scenarios, with and without the anterior cruciate ligament. Anterior and posterior medial meniscal strains were measured. Results: Two different braces each showed a significant reduction in the posteromedial meniscal strain ( p ⩽ 0.01) in an intact anterior cruciate ligament state. Neither brace mirrored this result for the anteromedial strain ( p > 0.05). In the deficient anterior cruciate ligament state, the braces had no significant effect on strain ( p > 0.05). Conclusion: Two unloader knee braces effectively reduced strain in the medial meniscus with an intact anterior cruciate ligament during dynamic activities. Neither brace made a significant reduction in strain for anterior cruciate ligament-deficient knees. Clinical relevance Unloader knee braces could be used to reduce the medial meniscus strain following meniscal surgery and during rehabilitation in patients with an isolated medial meniscus injury. However, these braces cannot be recommended for this purpose in patients with an anterior cruciate ligament deficiency.


2020 ◽  
pp. 036354652098007
Author(s):  
Etienne Cavaignac ◽  
Rémi Sylvie ◽  
Maxime Teulières ◽  
Andrea Fernandez ◽  
Karl-Heinz Frosch ◽  
...  

Background: Some authors have suggested that the semimembranosus tendon is involved in the pathophysiology of ramp lesions. This led us to conduct a gross and microscopic analysis of the posterior horn of the medial meniscus and the structures inserted on it. Hypothesis: (1) The semimembranosus tendon has a tendinous branch inserting into the posterior horn of the medial meniscus, and (2) the meniscotibial ligament is inserted on the posteroinferior edge of the medial meniscus. Study Design: Descriptive laboratory study. Methods: In total, 14 fresh cadaveric knees were dissected. From each cadaveric donor, a stable anatomic specimen was harvested en bloc, including the medial femoral condyle, medial tibial plateau, whole medial meniscus, cruciate ligaments, joint capsule, and distal insertion of the semimembranosus tendon. The harvested blocks were cut along the sagittal plane to isolate the distal insertion of the semimembranosus tendon on the posterior joint capsule and the posterior horn of the medial meniscus in a single slice. Histological slides were made from these samples and analyzed under a microscope. Results: In all knees, gross examination revealed a direct branch of the semimembranosus and a tendinous capsular branch ending behind the posterior horn of the medial meniscus. This capsular branch protruded over the joint capsule, over the meniscotibial ligament below and the meniscocapsular ligament above, but never ended directly in the meniscal tissue. The capsular branch was 14.3 ± 4.4 mm long (mean ± SD). The direct tendon inserted 11 ± 2.8 mm below the articular surface of the tibial plateau. The meniscotibial ligament inserted on the posteroinferior edge of the medial meniscus, and the meniscocapsular ligament insertion was on its posterosuperior edge. Highly vascularized adipose tissue was found, delimited by the posterior horn of the medial meniscus, meniscotibial ligament, meniscocapsular ligament, and capsular branch of the semimembranosus tendon. Conclusion: In all knees, our study found a capsular branch of the semimembranosus tendon inserted behind the medial meniscus. The meniscotibial ligament was inserted on the posteroinferior edge of the medial meniscus. Histological analysis of this area revealed that this ligament inserted differently from the insertion previously described in the literature. Clinical Relevance: This laboratory study provides insight into the pathophysiology of ramp lesions frequently associated with anterior cruciate ligament injury. To restore anatomy, it is mandatory to reestablish meniscotibial ligament continuity in ramp repairs.


2006 ◽  
Vol 19 (02) ◽  
pp. 110-112 ◽  
Author(s):  
P. A. Ridge

SummaryA three-year-old, female Border Collie was successfully treated for an isolated, torn, medial meniscus by arthroscopic meniscal tear resection. The dog returned to agility competition without recurrence of lameness.


2010 ◽  
Vol 51 (3) ◽  
pp. 296-301 ◽  
Author(s):  
Pieter Van Dyck ◽  
Filip M. Vanhoenacker ◽  
Jan L. Gielen ◽  
Lieven Dossche ◽  
Joost Weyler ◽  
...  

Background: The significance of borderline magnetic resonance (MR) findings that are equivocal for a tear of the knee meniscus remains uncertain. Given their higher signal-to-noise ratio (SNR) and greater spatial resolution, these equivocal meniscal tears could be expected to be less frequent using a 3.0T MR system. Purpose: To investigate the prevalence of equivocal meniscal tears using 3.0T MR, and to study their impact on MR accuracy compared with arthroscopy in the detection of meniscal tears. Material and Methods: The medical records of 100 patients who underwent 3.0T MR imaging and subsequent arthroscopy of the knee were retrospectively reviewed. Two observers interpreted MR images in consensus, and menisci were diagnosed as torn (abnormality on two or more images), equivocal for a tear (abnormality on one image), or intact, using arthroscopy as the standard of reference. The prevalence of equivocal meniscal tears was assessed, and MR accuracy was calculated as follows: first, considering both torn menisci and equivocal diagnoses as positive for a tear; and second, considering only torn menisci as positive for a tear. Results: Evidence of meniscal tears on MR images was equivocal in 12 medial (12%) and three lateral (3%) menisci. Of these equivocal MR diagnoses, tears were found at arthroscopy in eight medial and one lateral meniscus. In our study, the specificity and positive predictive value increased for both the medial and lateral meniscus when only menisci with two or more abnormal images were considered to be torn: from 80% and 89% to 91% and 94% for the medial meniscus, and from 91% and 73% to 93% and 78% for the lateral meniscus, respectively. Conclusion: Subtle findings that are equivocal for a tear of the knee meniscus still make MR diagnosis difficult, even at 3.0T. We recommend that radiologists should rather be descriptive in reporting subtle or equivocal MR findings, alerting the clinician of possible meniscal tear.


2018 ◽  
Vol 32 (11) ◽  
pp. 1128-1132
Author(s):  
Kun-Hui Chen ◽  
En-Rung Chiang ◽  
Hsin-Yi Wang ◽  
Hsiao-Li Ma

AbstractThe incidence of meniscal tear was reported to increase with the delay of anterior cruciate ligament reconstruction (ACLR). The tear may occur concurrently with the ACL injury or after the ACL injury. Few studies had focused on the patients whose meniscus is intact during ACL injury. We determined the correlation between timing of surgery and incidence of meniscal tears in ACL-deficient knees with initially intact meniscus. We retrospectively reviewed 387 patients who had undergone primary ACLR. Time of initial ACL injury, magnetic resonance imaging (MRI) examination, and surgery was recorded. The MRI was reviewed by experienced radiologic and orthopaedic doctors. Intraoperative arthroscopic images were also obtained and reviewed. The type of tear noted during surgery was classified according to the modification of International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine classification of meniscal tears. Patients were divided into early (surgery within 12 months from injury) and late surgery group (surgery at more than 12 months from injury). There were 216 patients with intact medial meniscus and 257 patients with intact lateral meniscus on the postinjury MRI study. The incidence of medial meniscus tear (MMT) was significantly higher than lateral meniscus tear (LMT) during the ACLR (33.8 vs. 19.8%, p < 0.001). The incidence of MMT is higher in late group than in early group (53.7 vs. 29.1%, p = 0.004, odds ratio= 2.815). The incidence of LMT is mildly higher in late group but without statistics significance (23.8 vs. 18.6%, p = 0.364). In both MMT and LMT, the most common injury pattern observed was a longitudinal tear. The incidence of each type is not different between early and late group. For patients without concurrent meniscal injuries with the ACL tear, the incidence of MMT significantly increased if ACLR was performed more than 12 months after injury. The medial meniscus was more prone to injury than the lateral meniscus in chronic ACL-deficient knee. ACLR should be performed earlier to reduce the risk of meniscal tears for patients without initially concurrent meniscal tear.


2021 ◽  
Vol 9 (2_suppl) ◽  
pp. 2325967121S0001
Author(s):  
Etienne Cavaignac ◽  
Remy Sylvie ◽  
Maxime Teulières ◽  
Andrea Fernandez ◽  
Bertrand Sonnery-Cottet

Objectives: The anatomical description of the posterior segment of the medial meniscus is debatable. The aim of this study was to describe by macroscopic and microscopic analysis the histological nature of the posterior segment of the medial meniscus and the inserted structures (semimembranosus tendon and menisco-tibial ligament) Methods: Fourteen fresh knees were dissected. For each specimen, a stable anatomical piece was taken en bloc, including the medial femoral condyle, the medial tibial condyle, the entire medial meniscus, the cruciate ligaments and the joint capsule, and the distal insertion of the semimembranosus tendon was preserved in its entirety. At this stage, a macroscopic analysis was performed. The blocks were cut along the sagittal plane in order to isolate the distal insertion of the semimembranosus tendon on the posterior joint capsule and the posterior segment of the medial meniscus in the same section. Histological slides were produced from these samples and were microscopically analyzed. Results: In all patients, the macroscopic analysis showed direct semimembranosus tendon expansion and tendinous capsular expansion ending behind the posterior segment of the medial meniscus. It projected onto the joint capsule, on the meniscotibial ligament at the bottom and the meniscocapsular ligament at the top, but never ended directly in the meniscal tissue. On average, the tendon directly inserted 11 ± 2.8 mm below the articular surface of the tibial plateau. The length of the capsular expansion was 14.3 ± 4.4 mm. The meniscotibial ligament was inserted in the posterior-inferior edge of the posterior segment of the medial meniscus and the meniscocapsular ligament in the posterior-superior edge. There was a particularly vascularized adipocyte space delimited by the posterior segment of the medial meniscus, the meniscotibial ligament, the meniscocapsular ligament and the capsular expansion of the semimembranosus tendon. Conclusion: We repeatedly noted capsular expansion of the semimembranosus tendon that inserted behind the medial meniscus. There is an interposing zone between the tendon insertion and the body of the meniscus which creates a fragile zone. The capsular tendon expansion also inserts in the meniscotibial ligaments at the bottom and meniscocapsular ligaments at the top.


2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Brett Walker ◽  
Andrew Limbert

Traumatic tears of the meniscus are well reported in the literature. Rarely, bilateral meniscal tears occur. A PubMed search found that only three cases of bilateral medial meniscus bucket handle type tears have been reported. Treatment options range from partial meniscectomy to repair of the meniscal tear. Repair is reported to be more successful in the vascular red-red or red-white zones. We present the case of a 23-year-old female who sustained simultaneous bilateral medial meniscus bucket handle type tears in an automobile accident. She was treated in a staged fashion with knee arthroscopy. Her meniscus tears were both found to be in the vascularized zone and meniscal tear repair was conducted. At two weeks postoperatively, she had excellent resolution of her symptoms and has returned to pain-free weight-bearing. She has remained pain-free at six-month follow-up.


Sign in / Sign up

Export Citation Format

Share Document