Evaluation, Treatment, and Outcomes of Meniscal Root Tears

Degenerative medial and lateral menisci root tears: demographics, clinical presentation, imaging features, and associated findings

PURPOSE

(I) Characterize the demographics and clinical features of patients with meniscal root tears (MRT); (II) analyze the morphology, extent, and grade of MRT on MRI; (III) evaluate associated abnormalities on imaging; and (IV) evaluate the associations between imaging findings, demographics, clinical features, and joint structural abnormalities.

MATERIAL AND METHODS

A search was performed to identify meniscal root tears. Age, sex, BMI, and pain were recorded. Knee radiographs and MRI were reviewed. Presence, grade and morphology of MRT, meniscal extrusion, insufficiency fractures, as well as joint structural abnormalities were scored. For goals (I), (II), and (III), tabulations for categorical variables and mean for continuous variables were computed. MRT findings variables were described using percentages. For goal (IV), adjusted linear and logistic regression were employed.

RESULTS

Ninety-six patients with a mean age of 56.6 years (69 females) and mean BMI of 28.9 kg/m2 were included; 88 of the MRT were located at the posterior horn of the medial meniscus (PHMM), and 82% were radial tear. The mean tear diameter was 3.8 mm, and 78/96 tears presented with meniscal extrusion. Nineteen patients presented with subchondral insufficiency fracture (SIF), which was significantly associated with the gap of the tear (p = 0.001) and grade of the meniscal root lesion (p = 0.005).

CONCLUSION

MRT typically found in middle-aged to older overweight and obese women. Lesions were mostly radial tears and located at PHMM and were frequently associated with meniscal extrusion and SIF. Moreover, the presence of SIF was significantly associated with the gap width and grade of root tear.

Root Repair Has Superior Radiological and Clinical Outcomes Than Partial Meniscectomy and Nonoperative Treatment in the Management of Meniscus Root Tears: A Systematic Review

PURPOSE

To compile and analyze structural and clinical outcomes after meniscus root tear treatment as currently described in the literature.

METHODS

A review was conducted to identify studies published since 2011 on efficacy of repair, meniscectomy, and nonoperative management in the treatment of meniscus root tears. Patient cohorts were grouped into treatment categories, with medial and lateral root tears analyzed separately; data were collected on patient demographics, structural outcomes including joint space width, degree of medial meniscal extrusion, progression to total knee arthroplasty, and patient-reported outcome measures. Risk of bias was assessed using the MINORS (methodological index for non-randomized studies) criteria. Heterogeneity was measured using the I-statistic, and outcomes were summarized using forest plots without pooled means.

RESULTS

The 56 included studies comprised a total of 3,191 patients. Mean age among the included studies ranged from 24.6 to 65.6 years, whereas mean follow-up ranged from 12 to 125.9 months. Heterogeneity analysis identified significant differences between studies. Change in joint space width ranged from -2.4 to -0.6 mm (i.e., decreased space) after meniscectomy (n = 186) and -0.9 to -0.1 mm after root repair (n = 209); change in medial meniscal extrusion ranged from -0.6 to 6.5 mm after root repair (n = 521) and 0.2 to 4.2 mm after meniscectomy (n = 66); and event rate for total knee arthroplasty ranged from 0.00 to 0.22 after root repair (n = 205), 0.35 to 0.60 after meniscectomy (n = 53), and 0.27 to 0.35 after nonoperative treatment (n = 93). Root repair produced the greatest numerical increase in International Knee Documentation Committee and Lysholm scores of the 3 treatment arms. In addition, root repair improvements in Knee Injury and Osteoarthritis Outcome Score Pain (range: 22-32), Sports and Recreational Activities (range: 23-36), Quality of Life (range: 22-42), and Symptoms subscales (range: 10-19), in studies with low risk of bias.

CONCLUSIONS

The literature reporting on the treatment of meniscus root tears is heterogenous and largely limited to Level III and IV studies. Current evidence suggests root repair may be the most effective treatment strategy in lessening joint space narrowing of the knee and producing improvements in patient-reported outcomes.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II-IV studies.

Posterior Meniscal Root Repair with Epidural Needle through the Combination of Arthroscopic Portals and Transtibial Tunnel

Posterior meniscal root repair is an expensive procedure because its performance often requires the use of specific devices. This issue is a limiting factor, especially in the public health system. Given this context, the development of alternative methods to treat these injuries became necessary. Among the available options, the technique combining the use of anterior portals and a tibial bone tunnel with an epidural needle has been proven to be effective and relevant due to its low cost. The present study aimed to provide technical guidance and suggestions to increase the success rate of this procedure, to enable its performance by knee surgeons in low-resource settings.

Biomechanical Comparison of Suture-Relay All-Suture Anchors and Conventional Suture Anchors for Posterior Medial Meniscus Root Repair in Porcine Models

Background

Posterior medial meniscus root (PMMR) tears (PMMRTs) can be repaired using various techniques to promote healing. However, the biomechanical properties of suture-relay all-suture anchor (ASA) versus conventional suture anchor (CSA) and loop-locking transtibial pullout (TTP) have not been well established.

Purpose

To compare the biomechanical properties of PMMR repairs using suture-relay ASA, CSA, and loop-locking TTP.

Study Design

Controlled laboratory study.

Methods

A total of 33 fresh-frozen porcine knee joints with intact medial menisci were randomly divided into 3 groups, with 11 specimens in each group: ASA, CSA, and TTP. The study involved cyclic loading, with displacement measurements taken after 100, 500, and 1000 cycles. Subsequently, the specimens were loaded until clinical failure (defined as 3-mm displacement) and then to ultimate failure of the construct, with data recorded for displacement after cyclic loading, load to 3-mm displacement, and ultimate load to failure.

Results

After 1000 cyclic loadings, the suture-relay ASA group showed considerably less displacement than the loop-locking TTP group (1.8 ± 0.7 mm vs 2.9 ± 0.3 mm; P < .001), but the displacements did not differ considerably between the suture-relay ASA and CSA groups (2.2 ± 0.9 mm; P > .05). The mean loads to clinical failure were significantly greater in the suture-relay ASA and CSA groups (61.3 ± 6.5 and 57.5 ± 9.7 N, respectively) than in the loop-locking TTP group (38.3 ± 9.4 N; P < .05). The ultimate load to failure was significantly greater in the suture-relay ASA group than in the loop-locking TTP group (153 ± 55.1 N vs 102 ± 12.9 N; P < .05). All specimens in the loop-locking TTP group failed by suture elongation mode, whereas only 2 specimens (18%) in the suture-relay ASA group and 5 specimens (45%) in the CSA group failed by suture elongation. Nine specimens (82%) in the suture-relay ASA group and 6 specimens (55%) in the CSA group failed due to suture cutout through the meniscal tissue.

Conclusion

The biomechanical properties after PMMR repair did not statistically differ between the suture-relay ASA and CSA groups. The suture-relay ASA technique had a higher load to failure than the loop-locking TTP technique.

Clinical Relevance

The suture-relay ASA technique is a promising option for the repair of PMMRTs; its repairing strength is also comparable to that of the CSA technique. Notably, the suture-relay ASA technique can be utilized without establishing a posteromedial portal, resulting in decreased procedure time and mitigating challenges associated with working from the posterior aspect of the knee.

Most Patients Older Than 40 Years of Age Who Underwent Meniscal Root Repair Presented With an Effusion, a Positive McMurray Test, and a Positive Hyperflexion Test

Purpose

To analyze the presenting symptoms and clinical examination findings of patients undergoing meniscal root repairs to aid physicians in diagnosing this injury.

Methods

All patients undergoing isolated arthroscopic meniscal root repair from January 1, 2016, to September 1, 2021, were identified. Patients younger than the age of 40 years were excluded. Clinical notes were reviewed for presenting symptoms and physical examination findings. Preoperative radiographs were graded using the Kellgren-Lawrence (KL) scale for osteoarthritis. Root tears were graded using the radiographic criteria of Chung et al. and articular cartilage injury was graded using a validated system, AMADEUS (mean total Area Measurement And Depth & Underlying Structures).

Results

In total, 221 patients met inclusion criteria; 65.6% of patients reported that their pain began after an acute injury, with 39.4% of patients reporting a "pop." On examination, an effusion was present in 71% of knees. McMurray test was reported positive in 85.5% and a positive hyperflexion test in 53.8% of knees. In total, 49.5% of knees were graded KL 1. 154 had medial root tears, 10 had lateral root tears, and 24 suffered both root tears. In total, 44.1% of tears occurred at the midsubstance of the root, with 28.0% occurring at the enthesis and 28.0% occurring at the root-posterior horn junction. The mean AMADEUS score was 94.4 ± 11.4.

Conclusions

Although most patients reported pain began after acute injury, less than one-half reported hearing a "pop." When patients were evaluated, an effusion, positive McMurray test, and positive hyperflexion test were present in most meniscal root tears.

Level of Evidence

Level IV, diagnostic case series.

Posterior Meniscus Root Repair Using a Retensionable Knotless All-Suture Anchor

Meniscus root injuries lead to increased tibiofemoral contact pressures and rapid progression of osteoarthritis. Early recognition and treatment with a meniscal root repair can restore biomechanics and help preserve the joint. The transtibial pullout repair and suture anchor repair are the most commonly used techniques to achieve anatomic fixation of the meniscal root. Still, each method presents distinct advantages and disadvantages. This Technical Note aims to describe a vastly simplified, more efficient, and reproducible posterior lateral meniscal root repair using a retensionable knotless all-suture anchor.

Repair of meniscus root tear - Is there a difference between medial meniscus root repair and lateral meniscus root repair? A systematic review and meta-analysis

PURPOSE

Complete meniscus root tear is associated with meniscus extrusion; this causes a loss of meniscus function and accelerated osteoarthritis of the knee. Existing small-scale retrospective case-control studies suggested that the outcomes were different between medial and lateral meniscus root repair. This meta-analysis aims to study whether such discrepancies exist via a systematic review of the available evidence in the literature.

METHODS

Studies evaluating the outcomes of surgical repair of posterior meniscus root tears, with reassessment MRI or second-look arthroscopy, were identified through a systematic search of PubMed, Embase, and Cochrane Library. The degree of meniscus extrusion, healing status of the repaired meniscus root, and functional outcome scores after repair were the outcomes of interest.

RESULTS

Among the 732 studies identified, 20 studies were included in this systematic review. 624 knees and 122 knees underwent MMPRT and LMPRT repair, respectively. The amount of meniscus extrusion following MMPRT repair was 3.8 ± 1.7 mm, which was significantly larger than the 0.9 ± 1.2 mm observed after LMPRT repair (p < 0.001). Significantly better healing outcomes were observed on reassessment MRI after LMPRT repair (p < 0.001). The postoperative Lysholm score and IKDC score was also significantly better after LMPRT than MMPRT repair (p < 0.001).

CONCLUSIONS

LMPRT repairs resulted in significantly less meniscus extrusion, substantially better healing outcomes on MRI, and superior Lysholm/IKDC scores, when compared to MMPRT repair. This is the first meta-analysis we are aware of that systematically reviews the differences in the clinical, radiographic, and arthroscopic results of MMPRT and LMPRT repair.

Etiology of posterior meniscus root tears: medial vs. lateral

PURPOSE

The aim of this study was to generate more information on the etiology and pathogenesis of medial (MM) and lateral (LM) meniscus root tears. Our hypothesis was that root tears of the MM predominantly result from degenerative damage, whereas root injuries of the LM are mainly of traumatic origin.

METHODS

Consecutively, 53 patients with a root tear of the medial meniscus (MMRT) and 51 patients with a root tear of the lateral meniscus (LMRT) were included in this study. The diagnosis was confirmed radiologically by MRI as well as arthroscopically. In addition to patient-specific data such as age, BMI and trauma history, the leg axis was determined and accompanying injuries (ligamentous and chondrogenic) were documented.

RESULTS

The mean age of the MMRT group was 57.2 (± 11.2) years, and that of the LMRT group 33.9 (± 11.4) years. The BMI was significantly higher in the MMRT group compared to the LMRT (30.5 vs. 25.1). 82.4% of patients in the LMRT group demonstrated an accompanying anterior cruciate ligament (ACL) rupture, whereas only 5.7% of the MMRT were associated with an ACL injury. A trauma was described in only 13.2% of patients of the MMRT group in contrast to 88.2% of the LMRT group. An extrusion > 3 mm of the MM in the coronal plane of MRI images could be detected in 86.8% of patients, whereas in the LMRT group, it was 15.7%. The mechanical varus angle was 5.6° in the MMRT group and 2.4° in the LMRT group. The rate and degree of concomitant cartilage damage in the affected compartment was significantly higher in the group with medial root injuries than in the group with lateral root tears.

CONCLUSIONS

The root injuries of the MM and LM show significant differences in terms of patient age, etiology and accompanying injuries. Root injuries to the medial meniscus are mostly of non-traumatic origin and more likely to occur in the context of medial osteoarthritis and varus deformity of the knee. Lateral root tears tend to be predominantly traumatic and are frequently associated with ACL ruptures. However, in the MMRT group, a small subgroup with a traumatic etiology and in the LMRT group a small subgroup of patients with non-traumatic etiology could be identified.

LEVEL OF EVIDENCE

III.

Meniscal Root Tears: An Update Focused on Preoperative and Postoperative MRI Findings

Meniscal root tears represent radial tears or avulsions of the meniscal cartilage at the tibial attachment site that profoundly affect meniscal biomechanics and kinematics. Meniscal root tears have the functional effect of a total meniscectomy and can lead to rapid degenerative change with development of early knee osteoarthritis (OA). A growing range of arthroscopic surgical techniques have been developed to repair meniscal root tears with the aim of restoring joint kinematics and contact pressures and delaying the development of OA. With increased understanding of the anatomy and biomechanics of the meniscal root, meniscal root injury repair has become the treatment of choice in knees with nonadvanced OA. This article reviews the anatomy and biomechanics of the meniscal roots, clinical and imaging diagnostic criteria of meniscal root tears, correlation between arthroscopy and MRI in the diagnosis and classification of meniscal root tears, and expected and abnormal MRI findings after meniscal root repair. Familiarity with MRI signs and classifications of meniscal root tears, as well as with root repair surgical techniques, can aid radiologists in correctly reporting preoperative and postoperative MRI findings.

Clinical significance and management of meniscal extrusion in different knee pathologies: a comprehensive review of the literature and treatment algorithm

The menisci are crescent-shaped, fibrocartilaginous structures that play a crucial role in the load transition and distribution of the contact forces along the tibiofemoral articulation. Meniscal extrusion (ME) is a radiological finding, especially in magnetic resonance imaging (MRI) scans, for which there has been growing interest in recent years. ME, in the coronary plane, is defined as the maximum distance of the most distal end of the meniscus from the border of the tibial plateau, where the tibial eminences are the most prominent, without taking into account the osteophytes. Although there is still controversy in the literature in respect of the optimal cutoff value, a threshold of 3 mm is considered significant. ME has no specific clinical finding or sign and it is encountered in many knee pathologies. It is associated with either rapidly progressive knee osteoarthritis or early onset of knee osteoarthritis and increased morbidity. In this review, we delineate the clinical significance of ME in various knee pathologies, as well as when, why and how it should be managed. To the best of our knowledge, this is the first study to elaborate on these topics.

Meniscal Extrusion: A Critical Analysis Review

➢

Pathologic meniscal extrusion can compromise meniscal function, leading to increased contact forces in the tibiofemoral compartment and the acceleration of osteoarthritic changes.

➢

Extrusion is typically defined as radial displacement of ≥3 mm outside the tibial border and is best diagnosed via magnetic resonance imaging, although ultrasonography has also demonstrated encouraging diagnostic utility.

➢

Surgical management of meniscal extrusion is based on the underlying etiology, the patient's symptom profile, the preexisting health of the articular surface, and the risk of future chondral injury and osteoarthritis.

Transosseous Meniscus Root Repair in Pediatric Patients and Association With Durable Midterm Outcomes and High Rates of Return to Sports

BACKGROUND

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 repairing meniscus root injuries to restore structure and function.

PURPOSE

To describe meniscus root tear patterns, associated injuries, and outcomes of transosseous meniscus root repair in a series of pediatric patients.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A single-institution retrospective review approved by the institutional review board was performed on consecutive adolescent patients aged <19 years with a meniscus posterior root tear treated with transosseous root repair over 4 years. All patients had a minimum 24-month clinical follow-up. The primary outcomes were revision meniscal surgery, and Lysholm, patient satisfaction, and Tegner activity scores.

RESULTS

A total of 20 patients (11 male and 9 female patients), with a mean age of 15.6 years (range, 13-18 years), met the inclusion criteria. There were 14 lateral meniscus root tears and 6 medial meniscus root tears. Seventeen patients (85%) had an associated ligament tear: 12 anterior cruciate ligament (ACL) tears and 5 posterior cruciate ligament tears. Two root tears occurred in isolation and both were the posterior root of the medial meniscus. The majority of meniscus root tears (n = 14 patients; 70%) were root avulsions (type 5). The mean follow-up was 42 months (range, 25-71 months). One patient underwent secondary surgery on the affected meniscus after a new injury 4 years postoperatively. Patient-reported outcomes were obtained for 16 patients (80%) at a mean 54-month follow-up. The median Lysholm score was 95 (interquartile range [IQR], 90-100). The median patient satisfaction score was 10 (IQR, 8-10). Thirteen of 16 patients (81%) reported returning to the same or higher level of sports after surgery.

CONCLUSION

Meniscus root tears most commonly occur in pediatric patients as root avulsions of the posterior root of the lateral meniscus and in association with ACL tears. This is unique compared with the adult population, in which the medial meniscus posterior root is often injured in isolation from a radial tear adjacent to the root. In our pediatric case series, transosseous root repair resulted in successful outcomes in the majority of patients, with durable results at the midterm follow-up.

Treatment, Return to Play, and Performance Following Meniscus Surgery

PURPOSE OF REVIEW

The standard of care in meniscal tear management is constantly evolving, especially for athletes and high-demand patients. Meniscus repairs, meniscus transplants, and partial meniscectomies are commonly performed, and rehabilitation methods following these operations are becoming more sophisticated. The ultimate goal of these procedures is returning patients to full activity with minimal risks. Return to play should be systematic, pathology dependent, and individualized to an athlete's needs, expectations, and level of play. This article provides a review of the current treatment modalities of meniscus tears, the rehabilitation protocols following each modality, and the return to play criteria that must be met before releasing the player to competition. In addition, it overviews articles that describe performance outcomes of patients that have undergone meniscus surgery.

RECENT FINDINGS

Current research shows high return to play rates for athletes that undergo meniscus surgery and describes effective rehabilitation protocols to facilitate recovery. There is an increased emphasis on meniscus preservation in recent literature. In addition, meniscus allograft transplantation has demonstrated its efficacy as a salvage procedure and has become a stronger consideration in the athlete with meniscus pathology. No standardized return to play protocol can be applied uniformly to all kinds of meniscal surgeries, and two athletes with the same pathology cannot be expected to follow identical paths towards full recovery. A multidisciplinary approach to care should be provided to the patients, and in the case of patients with high levels of athleticism, the road to recovery starts even before the injury itself.

Meniscal Root Repair Alone or Combined with Different Procedures After at Least 6 Months of Follow-Up: A Series of Cases

Purpose

To analyze clinical and functional outcomes of patients submitted to posterior meniscal root repair of the medial or lateral meniscus in different settings, with at least 6 months of follow-up.

Patients and Methods

Retrospective multicentric study assessing epidemiological characteristics and clinical-functional results of 22 patients who underwent meniscal root reinsertion (MRR) by transtibial technique. This study addressed different settings: isolated medial root repair, medial root repair associated with high tibial osteotomy (HTO) and lateral root repair associated with anterior cruciate ligament (ACL) reconstruction.

Results

Twelve patients had an isolated tear of the posterior root of the medial meniscus and underwent MRR alone. Six patients had a varus axis >5°, undergoing MRR in addition to HTO in the same surgical procedure. Four patients underwent repair of the posterior root of the lateral meniscus associated with simultaneous reconstruction of the ACL. The main results of the study were observed in the improvement of the IKDC score from 27.7% preoperatively to 69.8% in the postoperative period (p < 0.0001) and the Lysholm score of 44.4 points preoperatively to 88.4 points in the postoperative period (p < 0.0001). Significant clinical and subjective improvements were also reported.

Conclusion

Medial meniscal root repair, associated or not with valgus tibial osteotomy (when indicated) and lateral meniscal root repair associated with ACL reconstruction, improved clinical, functional, and subjective results of the patients presented in this case series in the short term.

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The Natural History of Medial Meniscal Root Tears: A Biomechanical and Clinical Case Perspective

Posterior medial meniscus root tears (PMMRTs) make up a relatively notable proportion of all meniscus pathology and have been definitively linked to the progression of osteoarthritis (OA). While known risk factors for development of OA in the knee include abnormal tibial coronal alignment, obesity and female gender, PMMRTs have emerged in recent years as another significant driver of degenerative disease. These injuries lead to an increase in average contact pressure in the medial compartment, along with increases in peak contact pressure and a decrease in contact area relative to the intact state. Loss of the root attachment impairs the function of the entire meniscus and leads to meniscal extrusion, thus impairing the force-dissipating role of the meniscus. Anatomic meniscus root repairs with a transtibial pullout technique have been shown biomechanically to restore mean and peak contact pressures in the medial compartment. However, nonanatomic root repairs have been reported to be ineffective at restoring joint pressures back to normal. Meniscal extrusion is often a consequence of nonanatomic repair and is correlated with progression of OA. In this study, the authors will describe the biomechanical basis of the natural history of medial meniscal root tears and will support the biomechanical studies with a case series including patients that either underwent non-operative treatment (5 patients) or non-anatomic repair of their medial meniscal root tears (6 patients). Using measurements derived from axial MRI, the authors will detail the distance from native root attachment center of the non-anatomic tunnels and discuss the ongoing symptoms of those patients. Imaging and OA progression among patients who were treated nonoperatively before presentation to the authors will be discussed as well. The case series thus presented will illustrate the natural history of meniscal root tears, the consequences of non-anatomic repair, and the findings of symptomatic meniscal extrusion associated with a non-anatomic repair position of the meniscus.

Meniscal Ramp Lesions and Root Tears: A Review of the Current Literature

The importance of the menisci in providing joint stability and their role in load transmission within the knee are well understood. A growing body of literature has emerged on 2 distinct injury patterns to these crucial anatomic structures, ramp lesions and root tears. Ramp lesions may be characterized as tears at the posterior meniscocapsular junction, while root tears involve bony or soft tissue avulsion of the meniscal insertions at the anterior or posterior intercondylar regions. In this 2-part review, we present an overview of the current available literature on ramp lesions and meniscal root tears, summarizing the unique anatomic considerations, etiology, biomechanics, management decisions, clinical outcomes pertinent to these very distinct injuries.

Alternative Techniques for Lateral and Medial Posterior Root Meniscus Repair Without Special Instruments

Improved understanding and treatment of posterior medial and lateral meniscus root tears have attracted increasing interest. These lesions significantly compromise meniscal function, which can result in an outcome resembling total meniscectomy, and are also a potential cause of knee instability. Despite facilitating repair procedures and reducing the operative time for these lesions, all-inside meniscal repair devices are not available in all circumstances or registered for use in all countries worldwide. Furthermore, all-inside arthroscopic devices can be expensive. Therefore, low-cost alternatives for the treatment of these lesions must be identified. We present 2 efficient and safe techniques: an outside-in technique for repairing medial meniscus root tears and a technique using a simple needle inserted through the transtibial tunnel for lateral meniscal root repairs, neither of which requires the use of specific instruments, thus enabling appropriate treatment of posterior medial and lateral meniscus root tears.

Meniscal Root Injuries

Meniscal root tears are an increasingly recognized injury leading to notable functional limitations, potential rapid cartilage deterioration of the affected compartment, and subsequent risk of total knee arthroplasty if left untreated. Repair of these tears is advised when articular cartilage remains intact because both medial and lateral meniscus root repairs have demonstrated favorable results. Recent literature demonstrates decreased rates of osteoarthritis and arthroplasty after medial meniscus root repair compared with partial meniscectomy and nonsurgical management. The transtibial pull-out repair technique is most commonly used and provides a biomechanically strong suture construct with standard and familiar knee arthroscopy portals. Furthermore, repair has recently been shown to be economically effective by decreasing overall societal healthcare costs when compared with more conservative management strategies. This review outlines the evaluation, treatment, and documented outcomes of meniscal root repair, which is imperative to the preservation of knee function and maintaining quality of life.

Treatment Outcomes of Meniscal Root Tears: A Systematic Review

Purpose

To report changes in outcomes for these 3 treatment options for meniscal root tears.

Methods

We systematically searched databases including PubMed, SCOPUS, and ScienceDirect for relevant articles. Criteria from the National Heart, Lung, and Blood Institute was used for a quality assessment of the included studies. A meta-analysis was performed to analyze changes in outcomes for meniscal repair.

Results

Nineteen studies, 12 level III and 7 level IV, were included in this systematic review, with a total of 1086 patients. Conversion to total knee arthroplasty (TKA) following partial meniscectomy ranged from 11% to 54%, 31% to 35% for nonoperative, conservative treatment, and 0% to 1% for meniscal repair. Studies comparing repair with either meniscectomy or conservative treatment found greater improvement and slower progression of Kellgren–Lawrence grade with meniscal repair. A meta-analysis of the studies included in the systematic review using forest plots showed repair to have the greatest mean difference for functional outcomes (International Knee Documentation Committee and Lysholm Activity Scale) and the lowest change in follow-up joint space.

Conclusions

In patients who experience meniscal root tears, meniscal repair may provide the greatest improvement in function and lowest risk of conversion to TKA when compared with partial meniscectomy or conservative methods. Partial meniscectomy appears to provide no benefit over conservative treatment, placing patients at a high risk of requiring TKA in the near future. However, future high-quality studies—both comparative studies and randomized trials—are needed to draw further conclusions and better impact treatment decision-making.

Level of Evidence

Level IV, systematic review of level III and level IV evidence

Collagenous Ultrastructure of the Torn Medial Meniscus Posterior Root: A Transmission Electron Microscopy Study

BACKGROUND

The collagen ultrastructure of torn medial meniscus posterior roots (MMPRs) has not been precisely defined.

PURPOSE

To investigate the ultrastructure of torn MMPRs, focusing on their collagen fibers, and to compare the collagen net architecture between intact and torn MMPRs using the Collagen Meniscal Architecture (CMA) scoring system.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Forty-three human meniscal specimens were obtained from 32 patients with osteoarthritis during total knee arthroplasty between January 2018 and November 2018. There were 23 specimens taken from patients with an MMPR tear and 20 taken from patients without an MMPR tear served as a control group. The presence of an MMPR tear was defined as a complete radial tear within 9 mm of the posterior root attachment. The collagen ultrastructure of the meniscal specimens was assessed with transmission electron microscopy using the CMA scoring system. Patient demographics included sex, age, and body mass index, and radiographic assessments included the Kellgren-Lawrence (K-L) grading system and the mechanical axis angle.

RESULTS

The median CMA score was significantly higher in torn MMPRs (5.5 [interquartile range, 3.5-6.0]) than in intact MMPRs (2.0 [interquartile range, 1.5-3.8]) (P < .001). When the CMA scores were converted to CMA grading, 23 torn MMPRs had 1 grade I, 9 grade II, and 13 grade III menisci. In 20 intact MMPRs, there were 12 grade I, 7 grade II, and 1 grade III menisci. No significant differences in sex, age, body mass index, K-L grade, or mechanical axis angle were found between groups.

CONCLUSION

This study showed that torn MMPRs had decreased numbers and disorganized courses of collagen fibers. The structural problem of torn MMPRs can negatively affect meniscal healing, function, and long-term survival after root repair.

CLINICAL RELEVANCE

These results might provide a histopathological reason for the low healing rate after MMPR repair.

Biomechanical Properties of Posterior Meniscal Root Repairs: A Systematic Review

PURPOSE

To systematically review the literature regarding the biomechanical properties of various meniscal root repair techniques.

METHODS

A systematic review of multiple databases was performed. The inclusion criteria included English language, studies relevant to meniscal root repairs, studies comparing 2 or more different discrete techniques, posterior root repairs, controlled laboratory studies, and human cadaveric or animal studies. Abstracts, case reports, cohort studies, case-control studies, systematic reviews and meta-analyses, and studies of meniscal body repairs were excluded.

RESULTS

Seventeen controlled laboratory studies were included for final analysis. There is no consensus on biomechanical superiority between transtibial pullout repair (TPR) and suture anchor repair. For TPR, there is no significant difference between 1 and 2 tibial tunnels. Nonanatomic repairs result in significantly lower joint surface contact areas and higher contact pressures, but suture placement farther from the root results in higher maximum load to failure. Two-suture repair has a greater maximum load to failure than 1-suture repair. Use of more than 2 sutures has diminishing returns. The modified Mason-Allen suture configuration is superior to a simple suture configuration, but there is no consensus regarding the superiority or feasibility of more complex sutures. There is no consensus on the superiority of a single suture material or shape.

CONCLUSIONS

Anatomic meniscal root repairs with either TPR or suture anchor repair have better joint surface contact pressures and contact surface areas than nonanatomic repairs. The use of 2 sutures results in better fixation than 1 suture. There is evidence that the modified Mason-Allen suture configuration is superior to a simple suture configuration in a TPR, although the benefits of more complicated configurations are unclear.

CLINICAL RELEVANCE

This study suggests that, in general, more complex sutures exhibit higher maximum loads. Increasing the number of sutures to up to 2 of the same configuration also increases the maximum load.

[Meniscal root lesions: clinical relevance and treatment]

Meniscal roots play an important role in load distribution of the tibiofemoral knee joint. Thus, meniscal root tears are severe injuries of the knee, which significantly expose cartilage to increased stress. Two entities are distinguished: (i) acute root tears that mainly affect the posterolateral root and often occur with ruptures of the anterior cruciate ligament; and (ii) chronic, degenerative root tears that mainly affect the posteromedial root. For diagnosis of both entities, the patient's medical history, a knee examination and especially MRI play key roles. The treatment of choice is in general transtibial fixation of the torn root, which leads to an increased clinical improvement and a decrease of the progression of arthritis.