Meniscal tears

Perspective on Clinical and Functional Outcomes of Arthroscopic All-Inside Meniscal Repair: Insights From a Lower Middle-Income Country

Background Meniscal tears are a common injury in the adult population. With the advent of newer devices, the adoption of the all-inside repair technique has been expanding substantially because of its feasibility and reduced risk to surrounding neurovascular structures. This study was conducted in a lower middle-income country to assess the functional outcome of the arthroscopic all-inside technique and to identify the potential factors that may affect the functional outcome that will eventually influence the future management of these patients. Method This study is a retrospective case series conducted at the Department of Orthopedic Surgery, Aga Khan University Hospital, Karachi, Pakistan. Patients presenting to the outpatient clinics with meniscal tears who underwent arthroscopic all-inside repair from January 2015 to December 2021 were included in this study. The exclusion criteria included patients who had associated fractures and patients with meniscal tears greater than six months ago. Results A total of 29 patients underwent all-inside meniscal repair for meniscus tears. The mean age of our patients was 26.31 years (SD = 7.11 years), ranging from 17 years to 48 years. Of these patients, 26 were males and three were females, accounting for 89.7% and 10.3%, respectively. The most frequent mechanism of injury was twisting while playing sports, accounting for 51.7%, followed by falling while playing sports and road traffic accidents (RTAs), accounting for 13.8% and 20.7%, respectively. Of the 29 patients, 16 (55.2%) had lateral meniscal injuries, 10 (34.5%) were diagnosed with medial meniscus injuries, and three (10.3%) had injuries to both menisci. The most common type of tear that was observed in our sample size was bucket handle tears, which were found in 14 patients, accounting for a total of 48.3%, followed by complex tears in seven patients (24.1%). The majority of the patients, i.e., 19 out of 29 patients (65.5%), had an acute course of injury, i.e., less than six weeks. For the functional outcome, the Lysholm score was calculated at 12 months and was found to be excellent in 17 patients, good in six patients, and fair in six patients, accounting for 58.6%, 20.7%, and 20.7%, respectively. The mean Lysholm score was 90.03 ± 8.85 points. Of the 29 patients, 27 (93.2%) had no complaints at the regular 12-month follow-up, whereas one patient (3.4%) experienced rotatory instability and one patient (3.4%) experienced stiffness at the knee joint. None of the patients had to undergo a reoperation. The mean Lysholm score in the 25 patients who had an associated anterior cruciate ligament tear was 89.64 ± 9.442 points, whereas the four patients who had an isolated meniscal tear had a mean score of 92.50 ± 2.887 points, which was not significantly different (p-value = 0.831). Conclusion All-inside meniscal repair for treating meniscal tears has become the new treatment paradigm as it not only renders excellent functional outcomes with minimal complications but also prevents damage to the surrounding neurovasculature and the soft tissue envelope as it is a minimally invasive technique.

Surgical Management of Traumatic Meniscus Injuries

The menisci increase the contact area of load bearing in the knee and thus disperse the mechanical stress via their circumferential tensile fibers. Traumatic meniscus injuries cause mechanical symptoms in the knee, and are more prevalent amongst younger, more active patients, compared to degenerative tears amongst the elderly population. Traumatic meniscus tears typically result from the load-and-shear mechanism in the knee joint. The treatment depends on the size, location, and pattern of the tear. For non-repairable tears, partial or total meniscal resection decreases its tensile stress and increases joint contact stress, thus potentiating the risk of arthritis. A longitudinal vertical tear pattern at the peripheral third red-red zone leads to higher healing potential after repair. The postoperative rehabilitation protocols after repair range from immediate weight-bearing with no range of motion restrictions to non-weight bearing and delayed mobilization for weeks. Pediatric and adolescent patients may require special considerations due to their activity levels, or distinct pathologies such as a discoid meniscus. Further biomechanical and biologic evidence is needed to guide surgical management, postoperative rehabilitation protocols, and future technology applications for traumatic meniscus injuries.

Meniscectomy is associated with a higher rate of osteoarthritis compared to meniscal repair following acute tears: a meta-analysis

PURPOSE

Meniscal tears are common and may impair knee function and biomechanics. This meta-analysis compared meniscal repair versus resection in patients with symptomatic meniscal tears in terms of patient-reported outcomes measures (PROMs), joint width, surgical failure, and rate of progression to osteoarthritis (OA) at conventional radiography.

METHODS

This study was conducted according to the 2020 PRISMA statement. In August 2023, the following databases were accessed: PubMed, Web of Science, Google Scholar, and Embase. Two reviewers independently performed the analysis and a methodological quality assessment of the included studies. All the clinical investigations which compared repair versus resection of meniscal tears were accessed.

RESULTS

Data from 20 studies (31,783 patients) were collected. The mean BMI was 28.28 ± 3.2 kg/m2, and the mean age was 37.6 ± 14.0 years. The mean time elapsed from injury to surgery was 12.1 ± 10.2 months and the mean medial joint width was 4.9 ± 0.8 mm. Between studies comparability at baseline was found in age, women, BMI, time from injury to surgery and length of the follow-up, PROMs, medial joint width, and stage of OA. The resection group demonstrated a greater Lysholm score (P = 0.02). No difference was found in the International Knee Documentation Committee (P = 0.2). Nine studies reported data on the rate of failures at a mean of 63.00 ± 24.7 months. No difference was found between the two groups in terms of persistent meniscal symptoms (P = 0.8). Six studies reported data on the rate of progression to total knee arthroplasty at a mean of 48.0 ± 14.7 months follow-up. The repair group evidenced a lower rate of progression to knee arthroplasty (P = 0.0001). Six studies reported data on the rate of advanced knee OA at a mean of 48.0 ± 14.7 months of follow-up. The repair group evidenced a lower rate of advanced knee OA (P = 0.0001). No difference was found in the mean joint space width (P = 0.09).

CONCLUSION

Meniscal repair is associated with a lower progression to knee osteoarthritis at approximately six years of follow-up compared to partial meniscectomy. No difference in PROMs, medial joint width, and failures were evidenced.

LEVEL OF EVIDENCE

Level III, meta-analysis.

Anterolateral Radial Meniscus Tear Repair using Traction Suture and Super-Hashtag Technique

Radial meniscus tears occur commonly as traumatic tears in younger patients, as well as in association with concomitant degenerative changes. Traditional management of these tears has centered around partial meniscectomy; however, there has been a more recent trend toward preserving the meniscus and attempting repair. Because of the gapping and displacement that frequently occurs with these tears, repair is often challenging and is done under high amounts of tension. The following article describes a technique using a traction suture to aid in maintaining reduction throughout repair. This is followed by the use of a combination of techniques to form a "super-hashtag" configuration of both vertical and horizontal mattress sutures, leading to a secure repair under little tension.

Heterogeneity of dynamic shear properties of the meniscus: A comparison between tissue core and surface layers

Damage to the meniscus has been associated with excessive shear loads. Aimed at elucidating meniscus pathophysiology, previous studies have investigated the shear properties of the meniscus fibrocartilaginous core. However, the meniscus is structurally inhomogeneous, with an external cartilaginous envelope (tibial and femoral surface layers) wrapping the tissue core. To date, little is known about the shear behavior of the surface layers. The objective of this study was to measure the dynamic shear properties of the surface layers and derive empirical relations with their composition. Specimens were harvested from tibial and femoral surface layers and core of porcine menisci (medial and lateral, n = 10 each). Frequency sweep tests yielded complex shear modulus (G*) and phase shifts (δ). Mechanical behavior of regions was described by a generalized Maxwell model. Correlations between shear moduli with water and glycosaminoglycans content of the tissue regions were investigated. The femoral surface had the lowest shear modulus, when compared to core and tibial regions. A 3-relaxation times Maxwell model satisfactorily interpreted the shear behavior of all tissue regions. Inhomogeneous tissue composition was also observed, with water content in the surface layers being higher when compared with tissue core. Water content negatively correlated with shear properties in all regions. The lower measured shear properties in the femoral layer may explain the higher prevalence of meniscal tears on the superior surface of the tissue. The heterogenous behavior of the tissue in shear provides insight into meniscus pathology and has important implications for efforts to tissue engineer replacement tissues.

Isokinetic Training Program to Improve the Physical Function and Muscular Performance of an Individual with Partial Injury of the Medial Meniscus: A Case Report

Background and Purpose

One of the best alternatives for the treatment of meniscal injuries in relation to surgical procedures, is exercise. This case report aimed to describe the effects of isokinetic training and a neuromuscular/proprioceptive exercise program on muscle performance and physical function in an individual after a rupture of the posterior horn of the medial meniscus.

Study Design

Case report.

Case Description

A 40-year-old man injured his right knee during a soccer match, with a partial lesion of the medial meniscus confirmed by magnetic resonance imaging. He completed an isokinetic training program in addition to exercises that targeted proprioception (22 sessions, 11 weeks) to improve physical function and performance, which were assessed before and after treatment and at a six-month follow-up. An individual with similar anthropometric characteristics was chosen to be used as a control for understanding the patient's assessment values.

Outcomes

Muscular performance of the knee flexors and extensors was evaluated isokinetically using the Biodex System-4 in a concentric mode at angular velocities of 60, 120, and 300 °/s . The main results indicated that after 11 weeks, the peak torque normalized to body mass (PT/BM), at 60 °/s of the knee extensors remained unchanged (2.54 N.m/kg) (below the control value - 3.06 N.m/kg), and at the six-month follow-up, increased by approximately 20% (3.08 N.m/kg). For the hamstrings, at 60 °/s, an increase of 18 % occurred after intervention (1.98 N.m/kg) and by approximately 30 % at the six-month follow-up (2.12 N.m/kg) - values much higher than the control 1.55 N.m/kg). This increase in the PT/BM was also reflected in the Hamstrings:Quadriceps ratio (78 %) after treatment which improved at follow-up (68 %).

Discussion

The results showed that the isokinetic training and neuromuscular/proprioceptive exercises improved the muscle performance of the knee flexors and extensors, after eleven weeks of intervention, and remained (or continued to improve) at the six-month follow-up.

Level of evidence

5, single case report.

Modeling the Impact of Meniscal Tears on von Mises Stress of Knee Cartilage Tissue

The present study aims to explore the stressed state of cartilage using various meniscal tear models. To perform this research, the anatomical model of the knee joint was developed and the nonlinear mechanical properties of the cartilage and meniscus were verified. The stress–strain curve of the meniscus was obtained by testing fresh tissue specimens of the human meniscus using a compression machine. The results showed that the more deteriorated meniscus had greater stiffness, but its integrity had the greatest impact on the growth of cartilage stresses. To confirm this, cases of radial, longitudinal, and complex tears were examined. The methodology and results of the study can assist in medical diagnostics for meniscus treatment and replacement.

Bucket-Handle Meniscus Tear Management With Meniscectomy Versus Repair Correlates With Patient, Socioeconomic, and Hospital Factors

INTRODUCTION

Bucket-handle meniscus tears are common knee injuries that are often treated surgically with meniscectomy or meniscal repair. Although clinical factors may influence the choice of one treatment approach over the other, the influence of patient, socioeconomic, and hospital factors remains poorly characterized. This study aimed to estimate the relative nationwide utilization of these two procedures and delineate a variety of factors that are associated with the selection of one treatment approach over the other.

METHODS

Meniscal repair and meniscectomy procedures conducted for isolated bucket-handle meniscus tears in 2016 and 2017 were identified in the Nationwide Ambulatory Surgery Sample database. Cases were weighted using nationally representative discharge weights. Univariate analyses and a multivariable logistic regression model were used to compare patient, socioeconomic, and hospital factors associated with meniscal repair versus meniscectomy.

RESULTS

In total, 12,239 cases were identified, which represented 17,236 cases after weighting. Of these, meniscal repair was conducted for 4,138 (24.0%). Based on the logistic regression model, meniscal repair was less likely for older and sicker patients. By contrast, several factors were associated with markedly higher odds of undergoing meniscal repair compared with meniscectomy. These included urban teaching hospitals; geographic location in the midwest, south, and west; and higher median household income.

DISCUSSION

Using a large nationally representative cohort, the current data revealed that only 24.0% of surgically treated bucket-handle meniscus tears were treated using repair. Identification of patient, socioeconomic, and hospital factors differentially associated with meniscal repair suggest that other factors may systematically influence surgical decision-making for this patient population. Surgeons should be conscious of these potential healthcare disparities when determining the optimal treatment for their patients.

LEVEL OF EVIDENCE

Level III.

Cost-Effectiveness Analysis of a Medial Meniscus Replacement Prosthesis for the Treatment of Patients with Medial Compartment Pain in the United Kingdom

BACKGROUND

The most common intra-articular knee injury is a meniscal tear, which commonly occurs secondary to trauma following twisting or hyperflexion. Treatment options for meniscal tears can either be surgical or non-surgical, and range from rest, exercise, bracing and physical therapy to surgical intervention, including meniscal repair and partial meniscectomy. In patients with persistent pain following loss of meniscus tissue, treatment can include partial replacement or meniscal allograft transplantation. The NUsurface^® prosthesis has been developed as a treatment option for patients experiencing persistent knee pain post medial meniscus (MM) surgery.

OBJECTIVE

The aim of this study was to assess the cost effectiveness of MM replacement using NUsurface for the treatment of patients with medial compartment pain following previous partial medial meniscectomy, from a UK health service perspective.

METHODS

An economic decision-analytic model was developed to assess the cost per quality-adjusted life-year (QALY) gained associated with the introduction of MM replacement using NUsurface compared with non-surgical standard of care, over a lifetime time horizon. The model structure was primarily informed by a previous clinical trial (VENUS) and was developed based on the clinical pathways typically followed by patients with this condition, with treatment pathways and probabilities of clinical progression adjusted depending on whether patients were receiving the intervention or undergoing current practice. A hypothetical cohort of adult patients (mean age of 50 years) was modelled, with clinical data sourced from the VENUS study as well as relevant UK literature. Both deterministic and probabilistic sensitivity analyses were carried out to explore uncertainty in the model results.

RESULTS

The base-case probabilistic results indicate that MM replacement using NUsurface is likely to be cost effective across a range of willingness-to-pay (WTP) thresholds (95% probability of being cost effective at the National Institute for Health and Care Excellence (NICE)-recommended £20,000 WTP threshold). Although per-patient costs increase, QALYs are also gained, with the incremental cost per QALY (probabilistic value = £5011) being below £20,000. Deterministic sensitivity analyses indicate that the parameters that have the greatest impact on results are the failure rate in the control group (current practice), utility scores, and the cost of undergoing MM replacement using NUsurface.

CONCLUSIONS

Based on the analysis presented, MM replacement with the NUsurface prosthetic implant is likely to be a cost-effective use of UK health care service resources compared with current standard care.

Yucatan Minipig Knee Meniscus Regional Biomechanics and Biochemical Structure Support its Suitability as a Large Animal Model for Translational Research

Knee meniscus injuries are the most frequent causes of orthopedic surgical procedures in the U.S., motivating tissue engineering attempts and the need for suitable animal models. Despite extensive use in cardiovascular research and the existence of characterization data for the menisci of farm pigs, the farm pig may not be a desirable preclinical model for the meniscus due to rapid weight gain. Minipigs are conducive to in vivo experiments due to their slower growth rate than farm pigs and similarity in weight to humans. However, characterization of minipig knee menisci is lacking. The objective of this study was to extensively characterize structural and functional properties within different regions of both medial and lateral Yucatan minipig knee menisci to inform this model’s suitability as a preclinical model for meniscal therapies. Menisci measured 23.2–24.8 mm in anteroposterior length (33–40 mm for human), 7.7–11.4 mm in width (8.3–14.8 mm for human), and 6.4–8.4 mm in peripheral height (5–7 mm for human). Per wet weight, biochemical evaluation revealed 23.9–31.3% collagen (COL; 22% for human) and 1.20–2.57% glycosaminoglycans (GAG; 0.8% for human). Also, per dry weight, pyridinoline crosslinks (PYR) were 0.12–0.16% (0.12% for human) and, when normalized to collagen content, reached as high as 1.45–1.96 ng/µg. Biomechanical testing revealed circumferential Young’s modulus of 78.4–116.2 MPa (100–300 MPa for human), circumferential ultimate tensile strength (UTS) of 18.2–25.9 MPa (12–18 MPa for human), radial Young’s modulus of 2.5–10.9 MPa (10–30 MPa for human), radial UTS of 2.5–4.2 MPa (1–4 MPa for human), aggregate modulus of 157–287 kPa (100–150 kPa for human), and shear modulus of 91–147 kPa (120 kPa for human). Anisotropy indices ranged from 11.2–49.4 and 6.3–11.2 for tensile stiffness and strength (approximately 10 for human), respectively. Regional differences in mechanical and biochemical properties within the minipig medial meniscus were observed; specifically, GAG, PYR, PYR/COL, radial stiffness, and Young’s modulus anisotropy varied by region. The posterior region of the medial meniscus exhibited the lowest radial stiffness, which is also seen in humans and corresponds to the most prevalent location for meniscal lesions. Overall, similarities between minipig and human menisci support the use of minipigs for meniscus translational research.

Knee meniscal retears after repair: A systematic review comparing diagnostic imaging modalities

The meniscus is a relatively avascular fibrocartilaginous structure that provides a key role in shock absorption and load transmission. However, accurate diagnosis of meniscal retear can present a clinical challenge. The purpose of this study was to conduct a systematic review on the available literature, which compare the sensitivities, specificities, and accuracies of different diagnostic modalities of diagnosing knee meniscal retears in patients who have undergone surgical meniscal repair, such as Magnetic Resonance Imaging (MRI), Magnetic Resonance Arthrography with intraarticular contrast (direct MRA), and a combination of MRI and direct MRA. Two authors independently searched two databases (PubMed and Scopus) for literature related to knee meniscus retear according to the PRISMA guidelines. Four studies were found, which resulted in 291 patients with 293 menisci. All studies were published in 2008 and 2014. In our analysis, we calculated sensitivity to be 78.79% (95% CI, 64.07–93.51), specificity to be 56.58% (95% CI, 20.21–92.94), and overall accuracy to be 66.25% (95% CI, 54.29–78.22) for MRI and sensitivity to be 87.84% (95% CI, 83.93–91.74), specificity to be 88.68% (95% CI, 81.93–95.43), and overall accuracy to be 87.22% (95% CI, 82.22–91.62) for direct MRA. We recommend the use of direct MRA for the diagnosis of meniscal retears due to its higher sensitivity, specificity, and accuracy as compared to MRI and its reduced cost and invasive nature as compared to second-look arthroscopy. However, our review is limited by the number of studies available on this topic. More studies using study designs such as randomized controlled trials, involving MRI, direct MRA, and combinations of such techniques, should be performed to accurately assess the different techniques and aid in designing guidelines to guide the diagnosis of meniscal retears following meniscal repair.

Meniscal Tear and ACL Injury Detection Model Based on AlexNet and Iterative ReliefF

Magnetic resonance (MR) is one of the special imaging techniques used to diagnose orthopedics and traumatology. In this study, a new method has been proposed to detect highly accurate automatic meniscal tear and anterior cruciate ligament (ACL) injuries. In this study, images in three different slices were collected. These are the sagittal, coronal, and axial slices, respectively. Images taken from each slice were categorized in 3 different ways: sagittal database (sDB), coronal database (cDB), and axial database (aDB). The proposed model in the study uses deep feature extraction. In this context, deep features have been obtained by using fully-connected layers of AlexNet architecture. In the second stage of the study, the most significant features were selected using the iterative RelifF (IRF) algorithm. In the last step of the application, the features are classified by using the k-nearest neighbor (kNN) method. Three datasets were used in the study. These datasets, sDB, and cDB, have four classes and consist of 442 and 457 images, respectively. The aDB used in the study has two class labels and consists of 190 images. The model proposed within the scope of the study was applied in 3 datasets. In this context, 98.42%, 100%, and 100% accuracy values were obtained for sDB, cDB, and aDB datasets, respectively. The study results showed that the proposed method detected meniscal tear and anterior cruciate ligament (ACL) injuries with high accuracy.

The Natural History of Medial Meniscal Tears in the ACL Deficient and ACL Reconstructed Rat Knee

OBJECTIVE

The process of anterior cruciate ligament (ACL) injury-induced meniscal tear formation is not fully understood. Clinical studies have shown that ACL reconstruction (ACLR) reduces the development of secondary meniscal tears, but it is difficult to gain insight into the protective effects of ACLR from clinical studies alone. Using rat ACL transection (ACLT) and ACLR models, we aimed to reveal (1) the formation process of meniscal tears secondary to ACLT and (2) the protective effects of ACLR on secondary meniscal tears.

DESIGN

ACLT surgery alone or with ACLR was performed on the knees of rats. Histomorphological and histopathological changes were examined in the posteromedial region of the meniscus in intact rats and in rats that received ACLT or ACLR up to 12 weeks postsurgery. In addition, anterior-posterior joint laxity was measured using the universal testing machine to evaluate the effects of ACLT and ACLR on joint laxity.

RESULTS

AAnterior-posterior laxity was significantly increased by ACLT compared to the intact knee. This ACLT-induced joint laxity was partially but significantly reduced by ACLR. Meniscal proliferation and hyaline cartilage-like tissue formation were detected in the medial meniscus at 4 weeks post-ACLT. At 12 weeks post-ACLT, hyaline cartilage-like tissue was replaced by ossicles and meniscal tears were observed. These ACLT-induced abnormalities were attenuated by ACLR.

CONCLUSIONS

Our results suggest that ACLT-induced joint laxity induces secondary medial meniscal tears through meniscal proliferation and ossicle formation via endochondral ossification. Joint re-stabilization by ACLR suppresses meniscal proliferation and ossicle formation and consequently prevents secondary meniscal tears.

A review of strategies for development of tissue engineered meniscal implants

The meniscus is a key stabilizing tissue of the knee that facilitates proper tracking and movement of the knee joint and absorbs stresses related to physical activity. This review article describes the biology, structure, and functions of the human knee meniscus, common tears and repair approaches, and current research and development approaches using modern methods to fabricate a scaffold or tissue engineered meniscal replacement. Meniscal tears are quite common, often resulting from sports or physical training, though injury can result without specific contact during normal physical activity such as bending or squatting. Meniscal injuries often require surgical intervention to repair, restore basic functionality and relieve pain, and severe damage may warrant reconstruction using allograft transplants or commercial implant devices. Ongoing research is attempting to develop alternative scaffold and tissue engineered devices using modern fabrication techniques including three-dimensional (3D) printing which can fabricate a patient-specific meniscus replacement. An ideal meniscal substitute should have mechanical properties that are close to that of natural human meniscus, and also be easily adapted for surgical procedures and fixation. A better understanding of the organization and structure of the meniscus as well as its potential points of failure will lead to improved design approaches to generate a suitable and functional replacement.

Development of a decellularized meniscus matrix-based nanofibrous scaffold for meniscus tissue engineering

The meniscus plays a critical role in knee mechanical function but is commonly injured given its central load bearing role. In the adult, meniscus repair is limited, given the low number of endogenous cells, the density of the matrix, and the limited vascularity. Menisci are fibrocartilaginous tissues composed of a micro-/nano- fibrous extracellular matrix (ECM) and a mixture of chondrocyte-like and fibroblast-like cells. Here, we developed a fibrous scaffold system that consists of bioactive components (decellularized meniscus ECM (dME) within a poly(e-caprolactone) material) fashioned into a biomimetic morphology (via electrospinning) to support and enhance meniscus cell function and matrix production. This work supports that the incorporation of dME into synthetic nanofibers increased hydrophilicity of the scaffold, leading to enhanced meniscus cell spreading, proliferation, and fibrochondrogenic gene expression. This work identifies a new biomimetic scaffold for therapeutic strategies to substitute or replace injured meniscus tissue. STATEMENT OF SIGNIFICANCE: In this study, we show that a scaffold electrospun from a combination of synthetic materials and bovine decellularized meniscus ECM provides appropriate signals and a suitable template for meniscus fibrochondrocyte spreading, proliferation, and secretion of collagen and proteoglycans. Material characterization and in vitro cell studies support that this new bioactive material is susceptible to enzymatic digestion and supports meniscus-like tissue formation.

Arthroscopic Diagnosis of Occult Posterolateral Meniscocapsular Separations: Another Hidden Lesion

Purpose

The purpose of this study was to describe the surgical findings and clinical outcomes in a series of patients with occult posterolateral meniscocapsular separations diagnosed arthroscopically after a negative magnetic resonance imaging (MRI) scan.

Methods

A retrospective analysis of prospectively collected data of consecutive patients who underwent surgical arthroscopy with repair of an occult posterolateral meniscocapsular separation by 2 fellowship-trained orthopaedic sports medicine surgeons at a single institution was performed. All lesions were identified arthroscopically in the posterolateral aspect of the lateral compartment as a distinct pathologic separation between the posterolateral capsule and adjacent meniscal tissue with increased excursion on probing. Clinical examination notes, MRI scans, and operative reports were reviewed. Patient-reported outcome measures were assessed via patient questionnaire.

Results

A total of 6 patients were included for analysis. MRI evaluation of the lateral meniscus was unrevealing in 4 patients, suggesting a possible tear of the body of the lateral meniscus in one patient and demonstrating a parameniscal cyst abutting the anterior root of the lateral meniscus in another patient. Arthroscopic examination revealed meniscocapsular separations of the posterolateral meniscus in all 6 knees, with 2 knees demonstrating concomitant bucket-handle meniscus tears. Patient-reported outcomes were determined for 67% of study patients. The average reported International Knee Documentation Committee score was 63.8, the average Knee Outcome Survey Activities of Daily Living Scale score was reported as 63, the 12-Item Short Form Survey (SF-12) Physical score averaged 46.8 with an average SF-12 Mental score of 59.9.

Conclusions

The diagnosis of occult posterolateral meniscocapsular separations (MCS) could be missed on advanced imaging, such as MRI, so arthroscopic diagnosis may be required. This study indicates that arthroscopic diagnosis and repair of occult posterolateral MCS results in good functional and clinical outcomes.

Level of Evidence

IV, therapeutic case series.

Forces at the Anterior Meniscus Attachments Strongly Increase Under Dynamic Knee Joint Loading

BACKGROUND

The anatomic appearance and biomechanical and clinical importance of the anterior meniscus roots are well described. However, little is known about the loads that act on these attachment structures under physiological joint loads and movements.

HYPOTHESES

As compared with uniaxial loading conditions under static knee flexion angles or at very low flexion-extension speeds, more realistic continuous movement simulations in combination with physiological muscle force simulations lead to significantly higher anterior meniscus attachment forces. This increase is even more pronounced in combination with a longitudinal meniscal tear or after total medial meniscectomy.

STUDY DESIGN

Controlled laboratory study.

METHODS

A validated Oxford Rig-like knee simulator was used to perform a slow squat, a fast squat, and jump landing maneuvers on 9 cadaveric human knee joints, with and without muscle force simulation. The strains in the anterior medial and lateral meniscal periphery and the respective attachments were determined in 3 states: intact meniscus, medial longitudinal tear, and total medial meniscectomy. To determine the attachment forces, a subsequent in situ tensile test was performed.

RESULTS

Muscle force simulation resulted in a significant strain increase at the anterior meniscus attachments of up to 308% (P < .038) and the anterior meniscal periphery of up to 276%. This corresponded to significantly increased forces (P < .038) acting in the anteromedial attachment with a maximum force of 140 N, as determined during the jump landing simulation. Meniscus attachment strains and forces were significantly influenced (P = .008) by the longitudinal tear and meniscectomy during the drop jump simulation.

CONCLUSION

Medial and lateral anterior meniscus attachment strains and forces were significantly increased with physiological muscle force simulation, corroborating our hypothesis. Therefore, in vitro tests applying uniaxial loads combined with static knee flexion angles or very low flexion-extension speeds appear to underestimate meniscus attachment forces.

CLINICAL RELEVANCE

The data of the present study might help to optimize the anchoring of meniscal allografts and artificial meniscal substitutes to the tibial plateau. Furthermore, this is the first in vitro study to indicate reasonable minimum stability requirements regarding the reattachment of torn anterior meniscus roots.

The Role of the Pie-Crusting Technique of the Medial Collateral Ligament in the Arthroscopic Inside-out Technique for Medial Meniscal Repair With or Without Anterior Cruciate Ligament Reconstruction: A Satisfactory Repair Technique

Purpose

To assess the results of a technique for pie crusting of the medial collateral ligament (MCL) and inside-out medial meniscal repair and perform a comparison with the literature.

Methods

This retrospective study consisted of electronic data collection between 2012 and 2017 with a minimum of 2 years’ follow-up. The inclusion criteria were the presence of difficult medial meniscal tears with joint tightness requiring pie crusting and the presence of acute or chronic tears of zone I or II with or without anterior cruciate ligament reconstruction (ACLR) using hamstring autograft during the same session. The primary outcome of the study was the achievement of good results with the aforementioned technique. There was no control group. All patients underwent assessments at 1, 2, and 6 months in outpatient clinics. At 6 months, the Lysholm knee score was calculated. For statistical analysis, the Social Science Statistics online program was used to perform descriptive analysis and assess any associations between the variables.

Results

This study included 53 patients from a single surgeon’s practice; of these patients, 31 underwent additional ACLR using hamstring autograft during the same session. The mean age was 29.43 years (range, 14-49 years), and the mean increase in the medial joint space width was 3.21 mm (range, 2-5 mm) with pie crusting. At 6 months, the average Lysholm score was 93 (range, 67-100) and the average visual analog scale score was 0.8 (range, 0-4). There was no meaningful association between age, tear pattern, chronicity of tear, joint space width obtained after pie crusting, and associated anterior cruciate ligament tear. Patients returned to their daily activity level at 4.5 months on average and returned to sporting activities at 7.4 months on average. Saphenous nerve symptoms were observed in 5 patients, but no infection or instability was documented in the follow-up period.

Conclusions

In this study, we obtained good outcomes using arthroscopic inside-out medial meniscal repair combined with pie crusting for the release of the MCL, with or without ACLR.

Level of Evidence

Level IV, therapeutic case series.

Molecular biology of meniscus pathology: Lessons learned from translational studies and mouse models

Injury to any individual structure in the knee interrupts the overall function of the joint and initiates a cascade of biological and biomechanical changes whose endpoint is often osteoarthritis (OA). The knee meniscus is an integral component of knee biomechanics and may also contribute to the biological homeostasis of the joint. Meniscus injury altering knee function is associated with a high risk of OA progression, and may also be involved in the initiation of OA. As the relationship between meniscus injury and OA is very complex; despite the availability of transcript level data on human meniscus injury and meniscus mediated OA, mechanistic studies are lacking, and available human data are difficult to validate in the absence of patient-matched noninjured control tissues. As similarities exist between human and mouse knee joint structure and function, investigators have begun to use cutting-edge genetic and genomic tools to examine the usefulness of the mouse as a model to study the intricate relationship between meniscus injury and OA. In this review, we use evidence from human meniscus research to identify critical barriers hampering our understanding of meniscus injury induced OA and discuss strategies to overcome these barriers, including those that can be examined in a mouse model of injury-mediated OA.

Meniscal Tears: Current Understanding, Diagnosis, and Management

From once being labelled as a functionless remain of leg muscle, extensive scientific investigations in recent decades have described the meniscus as one of the most crucial structures of the knee. The incidence of meniscal injuries is on the rise and can be attributed to the increased participation of youth in sporting activities. MRI continues to be the imaging modality of choice, and surgical management is the mainstay of treatment for meniscal tears. Arthroscopic partial meniscectomy (APM) is currently the most performed orthopedic procedure around the globe. However, recent studies have conclusively shown that outcomes after an APM are no better than the outcomes after a sham/placebo surgery. Meniscal repair is now being touted as a viable and effective alternative. Meniscal repair aims to achieve meniscal healing while completely avoiding the adverse effects of partial meniscectomy. Meniscal repairs have grown in popularity over the past three decades and have proved to be a much more efficient alternative to partial meniscectomy. It is now increasingly recommended to attempt meniscal repair in all repairable tears, especially in young and physically active patients. Partial Meniscal implants have also shown excellent outcomes in long-term studies, but its efficacy in acute settings still requires further research. Research performed on various techniques of meniscal regeneration looks promising, and regenerative medicine appears to be the way forward. This review aims to critically discuss the current understanding of the meniscus, its role in biomechanics of the knee joint, and the current methods used to diagnose and manage meniscal tears.

Quantitative Evaluation of Dynamic Lateral Meniscal Extrusion After Radial Tear Repair

Background:

Radial tears of the lateral meniscus frequently accompany acute anterior cruciate ligament (ACL) injuries and lead to increased joint stress and pathological meniscal extrusion (ME). The dynamic behavior of the lateral meniscus after radial tear repair with respect to ME has not been described.

Purpose:

To quantitatively assess dynamic lateral ME after all-inside radial tear repair.

Study Design:

Case series; Level of evidence, 4.

Methods:

Patients who underwent ACL reconstruction and all-inside radial tear repair of the lateral meniscus and had no history of contralateral knee injuries were included. Magnetic resonance imaging scans were acquired in loaded (50% of body weight) and unloaded conditions of both the injured and noninjured knees. A custom-made pneumatically driven knee brace was used for standardized knee positioning in 10° of flexion and with axial load application. Quantitative measures included the absolute lateral ME, meniscal body extrusion ratio, and Δ extrusion. Preoperative and postoperative unloaded extrusion data were compared by paired t tests. For postoperative data, the concomitant influence of the factors “leg” and “condition” were assessed through factorial analyses of variance.

Results:

A total of 10 patients with a mean follow-up of 47.9 months were enrolled. The intraclass correlation coefficient (ICC) confirmed good interrater reliability (ICC, 0.898) and excellent intrarater reliability (ICC, 0.976). In the unloaded injured leg, all-inside repair reduced ME from 3.15 ± 1.07 mm to 2.13 ± 0.61 mm (–32.4%; P = .033). Overall, load application led to a significant increase in ME (+0.34 mm [+21.8%]; P = .029). Significantly greater ME was observed in the injured knee (+1.10 mm [+93.2%]; P = .001) than in the noninjured knee. The condition × leg interaction was not significant (P = .795), suggesting that the compression-associated increase in ME did not differ significantly between the injured and noninjured knees.

Conclusion:

Lateral ME depends on the knee status and loading condition. All-inside repair of radial meniscal tears led to a reduction of extrusion with no alteration in dynamic lateral ME. Meniscus-preserving therapy is recommended in the case of a radial lateral meniscal tear to preserve its dynamic behavior.

The Meniscus in Normal and Osteoarthritic Tissues: Facing the Structure Property Challenges and Current Treatment Trends

The treatment of meniscus injuries has recently been facing a paradigm shift toward the field of tissue engineering, with the aim of regenerating damaged and diseased menisci as opposed to current treatment techniques. This review focuses on the structure and mechanics associated with the meniscus. The meniscus is defined in terms of its biological structure and composition. Biomechanics of the meniscus are discussed in detail, as an understanding of the mechanics is fundamental for the development of new meniscal treatment strategies. Key meniscal characteristics such as biological function, damage (tears), and disease are critically analyzed. The latest technologies behind meniscal repair and regeneration are assessed.

Meniscal Repair in Pediatric Populations: A Systematic Review of Outcomes

Background:

Loss of meniscal tissue in the pediatric population can have long-term consequences on joint health, highlighting the importance of meniscal preservation in this group.

Purpose:

To systematically review reported knee outcome measures and complication rates after repair of meniscal tears in children and adolescents.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A review of the literature regarding the existing evidence for pediatric meniscal tear outcomes was performed through use of the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (1980-present), and MEDLINE (1980-present). Included were articles in English that reported the outcomes of meniscal tears in the pediatric population (<18 years old) with a follow-up of more than 12 months. Clinical outcome scores were reviewed.

Results:

A total of 1003 total studies were initially retrieved, with 8 meeting the inclusion criteria. The review included 287 patients (165 male, 122 female), mean age 15.1 years (range, 4-18 years), with 301 meniscal tears (reported: 134 medial, 127 lateral, and 32 both medial and lateral, 8 location unspecified). Concomitant anterior cruciate ligament reconstruction was performed in 52% (158/301) of meniscal repairs. The average reported postoperative Lysholm scores ranged from 85.4 to 96.3, and the average reported postoperative Tegner activity scores ranged from 6.2 to 8.

Conclusion:

Arthroscopic repair of a meniscal tear in the pediatric and adolescent population is an effective treatment option that has a low failure rate, enhances postoperative clinical outcomes, and preserves meniscal tissues.

Biomechanical Study of Meniscal Repair Using Horizontal Sutures and Vertical Loop Techniques

Background:

Meniscus plays an important role in weight-bearing and energy absorption. Moreover, its function is optimal to maintain joint stability and congruous. Treatments for meniscus damage or meniscus tear include open or arthroscopic repair and meniscectomy. One of the most important factors that influence patients’ recovery outcome is restoration technique. The purpose of this study was to compare the strength of recently new method of meniscus repair, submeniscal horizontal sutures, and single vertical loop suturing techniques in meniscus repair.

Materials and Methods:

An experimental study was conducted to study 12 ruptured medial meniscuses of bulls, which were divided into two groups of six meniscuses equally. In this study, submeniscal horizontal and vertical loop suturing techniques were compared based on their resistance to tensile forces and the stability of repaired gaps.

Results:

In this study, submeniscal horizontal and vertical loop knots were 104.3 ± 12.5 N and 110.7 ± 16.4 N, respectively. No significant difference was found between the two groups. To measure the stability of the gap, 95.4 ± 8.7 N tensile force was applied to submeniscal and 124.6 ± 11.7 N to vertical loop techniques. There was significantly different in gap stability between horizontal and vertical loop techniques in meniscal repair (P = 0.02).

Conclusion:

The results of this study indicate that knot resistance in submeniscal horizontal is similar to vertical loop resistance. The stability of the restored gap in vertical loop technique is more than submeniscal horizontal techniques. Vertical loop causes greater stability against tensile force.

Considerations for translation of tissue engineered fibrocartilage from bench to bedside

Fibrocartilage is found in the knee meniscus, the temporomandibular joint (TMJ) disc, the pubic symphysis, the annulus fibrosus of intervertebral disc, tendons, and ligaments. These tissues are notoriously difficult to repair due to their avascularity, and limited clinical repair and replacement options exist. Tissue engineering has been proposed as a route to repair and replace fibrocartilages. Using the knee meniscus and TMJ disc as examples, this review describes how fibrocartilages can be engineered toward translation to clinical use. Presented are fibrocartilage anatomy, function, epidemiology, pathology, and current clinical treatments because they inform design criteria for tissue engineered fibrocartilages. Methods for how native tissues are characterized histomorphologically, biochemically, and mechanically to set gold standards are described. Then, provided is a review of fibrocartilage-specific tissue engineering strategies, including the selection of cell sources, scaffold or scaffold-free methods, and biochemical and mechanical stimuli. In closing, the Food and Drug Administration paradigm is discussed to inform researchers of both the guidance that exists and the questions that remain to be answered with regard to bringing a tissue engineered fibrocartilage product to the clinic.

Superolateral Hoffa's Fat Pad Edema and Trochlear Sulcal Angle Are Associated With Isolated Medial Patellofemoral Compartment Osteoarthritis

PURPOSE

To evaluate whether mediopatellar plica and knee morphometric measurements obtained from magnetic resonance imaging (MRI) studies are associated with isolated medial patellofemoral osteoarthritis in young adults.

METHODS

MRI studies from 60 patients with isolated medial patellofemoral osteoarthritis and 90 control patients with normal knee MRI studies were reviewed. The presence of mediopatellar plica, the presence of edema in the superolateral aspect of Hoffa's fat pad and suprapatellar fat pad, quadriceps and patellar tendinosis, and axial and sagittal alignment of the patellar and trochlear morphology were assessed using MRI. The relationship between mediopatellar plica, alignment, or morphology and the presence of isolated medial patellofemoral osteoarthritis was evaluated using logistic regression.

RESULTS

Superolateral Hoffa's fat pad edema (odds ratio [OR] = 3.4, P = .009) and decreased trochlear sulcal angle (OR = 0.95, P = .045) were associated with increased odds of isolated medial patellofemoral osteoarthritis. Decreased lateral patellar tilt (OR = 0.93, P = .087) and patellar tendinosis (OR = 4.13, P = .103) trended toward being associated with increased odds of isolated medial patellofemoral osteoarthritis but were not statistically significant. No significant association was seen between the presence of mediopatellar plica and medial patellofemoral osteoarthritis (OR = 0.95, P = .353).

CONCLUSIONS

Medial patellofemoral osteoarthritis is associated with trochlear morphology and patellar alignment but not with mediopatellar plica.

Clinical efficacy of meniscus plasty under arthroscopy in middle-aged and elderly patients with meniscus injury

Clinical efficacy of meniscal plasty and total meniscectomy under arthroscopy in treating middle-aged and elderly patients with meniscus injury were explored. One hundred and fifteen elderly patients with meniscal injuries treated in the First Peoples Hospital of Wujiang District Suzhou from May 2012 to October 2014 were retrospectively analyzed. They were randomly divided into meniscal plasty group (experimental group) and total meniscectomy group (control group). Length of stay, operation time and VAS between the two groups were compared. Knee function was evaluated before the surgery and at the final follow-up using IKDC 2000 and Lysholm score. The differences of postoperative clinical efficacy and complications in both groups were observed. Postoperative IKDC 2000 and Lysholm score in the experimental group were superior to those of control group (P<0.001). There was no significant difference in the relieving effect of knee pain between the two types of procedures (P>0.05). Shorter operation time was found in control than that of experimental group. We did not observe remarkable differences in length of stay and postoperative complication rate between the two groups (P>0.05). Both meniscal plasty and total meniscectomy under arthroscopy can effectively relieve knee pain in a short time. Meniscal plasty could remarkably alleviate the progression of knee osteoarthritis, maintain knee function and improve daily life of affected population. We considered that meniscal plasty should be served as the preferred approach in treating middle-aged and elderly patients with meniscus injury.

Modern treatment of meniscal tears

The complex ultrastructure of the meniscus determines its vital functions for the knee, the lower extremity, and the body.

The most recent concise, reliable, and valid classification system for meniscal tears is the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) Classification, which takes into account the subsequent parameters: tear depth, tear pattern, tear length, tear location/rim width, radial location, location according to the popliteal hiatus, and quality of the meniscal tissue.

It is the orthopaedic surgeon’s responsibility to combine clinical information, radiological images, and clinical experience in an effort to individualize management of meniscal tears, taking into account factors related to the patient and lesion.

Surgeons should strive not to operate in most cases, but to protect, repair or reconstruct, in order to prevent early development of osteoarthritis by restoring the native structure, function, and biomechanics of the meniscus.

Currently, there are three main methods of modern surgical management of meniscus tears: arthroscopic partial meniscectomy; meniscal repair with or without augmentation techniques; and meniscal reconstruction. Meniscus surgery has come a long way from the old slogan, “If it is torn, take it out!” to the currently accepted slogan, “Save the meniscus!” which has guided evolving modern treatment methods for meniscal tears. This last slogan will probably constitute the basis for newer alternative biological treatment methods in the future.

Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170067.

In Vivo Tibial Cartilage Strains in Regions of Cartilage-to-Cartilage Contact and Cartilage-to-Meniscus Contact in Response to Walking

BACKGROUND

There are currently limited human in vivo data characterizing the role of the meniscus in load distribution within the tibiofemoral joint. Purpose/Hypothesis: The purpose was to compare the strains experienced in regions of articular cartilage covered by the meniscus to regions of cartilage not covered by the meniscus. It was hypothesized that in response to walking, tibial cartilage covered by the meniscus would experience lower strains than uncovered tibial cartilage.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Magnetic resonance imaging (MRI) of the knees of 8 healthy volunteers was performed before and after walking on a treadmill. Using MRI-generated 3-dimensional models of the tibia, cartilage, and menisci, cartilage thickness was measured in 4 different regions based on meniscal coverage and compartment: covered medial, uncovered medial, covered lateral, and uncovered lateral. Strain was defined as the normalized change in cartilage thickness before and after activity.

RESULTS

Within each compartment, covered cartilage before activity was significantly thinner than uncovered cartilage before activity ( P < .001). After 20 minutes of walking, all 4 regions experienced significant cartilage thickness decreases ( P < .01). The covered medial region experienced significantly less strain than the uncovered medial region ( P = .04). No difference in strain was detected between the covered and uncovered regions in the lateral compartment ( P = .40).

CONCLUSION

In response to walking, cartilage that is covered by the meniscus experiences lower strains than uncovered cartilage in the medial compartment. These findings provide important baseline information on the relationship between in vivo tibial compressive strain responses and meniscal coverage, which is critical to understanding normal meniscal function.

Knee Menisci

The menisci of the knees are semicircular fibrocartilaginous structures consisting of a hydrophilic extracellular matrix containing a network of collagen fibers, glycoproteins, and proteoglycans maintained by a cellular component. The menisci are responsible for more than 50% of load transmission across the knee and increase joint congruity thereby also aiding in fluid film lubrication of the joint. In the United Kingdom, meniscal tears are the most common form of intra-articular knee injury and one of the commonest indications for orthopedic intervention. The management of these injuries is dependent on the location within the meniscus (relative to peripheral blood supply) and the pattern of tear. Removal of meniscus is known to place the knee at increased risk of osteoarthritis; therefore repair of meniscal tears is preferable. However, a significant proportion of tears are irreparable and can only be treated by partial or even complete meniscectomy. More recent studies have shown encouraging results with meniscal replacement in this situation, though further work is required in this area.

PURLs: When can exercise supplant surgery for degenerative meniscal tears?

Patients with a medial, degenerative meniscal tear and a minimal history of osteoarthritis make good candidates for physical therapy-- and there is an added benefit, too.

Meniscal biology in health and disease

The knee is a fascinating yet complex joint. Researchers and clinicians agree that the joint is an organ comprised of highly specialized intrinsic and extrinsic tissues contributing to both health and disease. Key to the function and movement of the knee are the menisci, exquisite fibrocartilage structures that are critical structures for maintaining biological and biomechanical integrity of the joint. The biological/physiological functions of the menisci must be understood at the tissue, cellular and even molecular levels in order to determine clinically relevant methods for assessing it and influencing it. By investigating normal and pathological functions at the basic science level, we can begin to translate data to patients. The objective of this article is to provide an overview of this translational pathway so that progression toward improved diagnostic, preventative, and therapeutic strategies can be effectively pursued. We have thoroughly examined the pathobiological, biomarker, and imaging aspects of meniscus research. This translational approach can be effective toward optimal diagnosis, prevention, and treatment for the millions of patients who suffer from meniscal disorders each year.

Meniscus tear surgery and meniscus replacement

OBJECTIVE

the menisci are easily injured and difficult to repair. The aim of this study was to analyze the current state of meniscal surgery aimed at preserving morphology and conserving the biomechanics of the knee to prevent joint degeneration.

METHODOLOGY

a search of the electronic medical literature database Medline was conducted, from http://www.ncbi.nlm.nih.gov/pubmed. The search was not limited by language. Candidate articles were identified by searching for those that included the keywords meniscus, surgery, suture, implant, allograft. The limits were included for clinical research and clinical trials. Basic research was not included. The studies selected were evaluated and classified in three different categories: basic science, reconstruction (suture and meniscectomy) and implants (scaffolds and allograft).

RESULTS

the consequences of meniscectomy performed at a young age can lead to a joint cartilage degeneration twenty years later. There are few surgical options for the repair of meniscal injuries in order both to preserve the meniscus and to ensure the long term survival of the knee joint, meniscectomy, repair, suturing the tear, or reconstruction, when a meniscal allograft or synthetic substitute is used to replace the meniscus, but the biomechanical properties of the native meniscus are not reproduced entirely by the scaffolds that exist today.

CONCLUSION

therapies that successfully repair or replace the meniscus are therefore likely to prevent or delay osteoarthritis progression.

Diagnostic accuracy of the Thessaly test, standardised clinical history and other clinical examination tests (Apley's, McMurray's and joint line tenderness) for meniscal tears in comparison with magnetic resonance imaging diagnosis

BACKGROUND

Reliable non-invasive diagnosis of meniscal tears is difficult. Magnetic resonance imaging (MRI) is often used but is expensive and incidental findings are problematic. There are a number of physical examination tests for the diagnosis of meniscal tears that are simple, cheap and non-invasive.

OBJECTIVES

To determine the diagnostic accuracy of the Thessaly test and to determine if the Thessaly test (alone or in combination with other physical tests) can obviate the need for further investigation by MRI or arthroscopy for patients with a suspected meniscal tear.

DESIGN

Single-centre prospective diagnostic accuracy study.

SETTING

Although the study was performed in a secondary care setting, it was designed to replicate the results that would have been achieved in a primary care setting.

PARTICIPANTS

Two cohorts of patients were recruited: patients with knee pathology (n = 292) and a control cohort with no knee pathology (n = 75).

MAIN OUTCOME MEASURES

Sensitivity, specificity and diagnostic accuracy of the Thessaly test in determining the presence of meniscal tears.

METHODS

Participants were assessed by both a primary care clinician and a musculoskeletal clinician. Both clinicians performed the Thessaly test, McMurray's test, Apley's test, joint line tenderness test and took a standardised clinical history from the patient.

RESULTS

The Thessaly test had a sensitivity of 0.66, a specificity of 0.39 and a diagnostic accuracy of 54% when utilised by primary care clinicians. This compared with a sensitivity of 0.62, a specificity of 0.55 and diagnostic accuracy of 59% when used by musculoskeletal clinicians. The diagnostics accuracy of the other tests when used by primary care clinicians was 54% for McMurray's test, 53% for Apley's test, 54% for the joint line tenderness test and 55% for clinical history. For primary care clinicians, age and past history of osteoarthritis were both significant predictors of MRI diagnosis of meniscal tears. For musculoskeletal clinicians age and a positive diagnosis of meniscal tears on clinical history taking were significant predictors of MRI diagnosis. No physical tests were significant predictors of MRI diagnosis in our multivariate models. The specificity of MRI diagnosis was tested in subgroup of patients who went on to have a knee arthroscopy and was found to be low [0.53 (95% confidence interval 0.28 to 0.77)], although the sensitivity was 1.0.

CONCLUSIONS

The Thessaly test was no better at diagnosing meniscal tears than other established physical tests. The sensitivity, specificity and diagnostic accuracy of all physical tests was too low to be of routine clinical value as an alternative to MRI. Caution needs to be exercised in the indiscriminate use of MRI scanning in the identification of meniscal tears in the diagnosis of the painful knee, due to the low specificity seen in the presence of concomitant knee pathology. Further research is required to determine the true diagnostic accuracy and cost-effectiveness of MRI for the detection of meniscal tears.

TRIAL REGISTRATION

Current Controlled Trial ISRCTN43527822.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Study of the Clinical Outcome between Traumatic and Degenerative (non-traumatic) Meniscal Tears after Arthroscopic Surgery: A 4-Years Follow-up Study

INTRODUCTION

The meniscus is a biconcave fibrocartilage in the knee joint interpose between the femoral condyles and tibial plateau; the meniscus has functions in load bearing, load transmission, shock absorption joint stability, joint lubrication, and joint congruity.

AIM

The aim of this study is to provide orthopeadic surgeon a base of reference in the choice of the optimal course of management for meniscal tears.

MATERIALS AND METHODS

One hundred and seventeen patients met the criteria of inclusion for the present study. Patients were divided in two groups T and NT according to the presence of distinct previous traumatic events to the knees. Two subgroups were formed in each groups T and NT respectively at a mean follow up of 1 and 4 years. Postoperative clinical outcome were assessed using Lysholm scores and Rand SF-36 survey.

RESULTS

One hundred and seventeen patients were included in the present study with 60(51.28%) patients in the traumatic group and 57(48.71%) in the degenerative group. 95(81.19%) patients in total were satisfied with their health status at end of follow up. The mean value of Lysholm scores at 1 year were respectively 85.25±8.78 for traumatic group and 86.38±12.14 for non-traumatic group and at 4 years were respectively 92.63±7.31 for traumatic group and 72.90±20.77 for non-traumatic group. According to Rand SF-36 health, traumatic group showed better improvements compare to non-traumatic group between 1 and 4 years after arthroscopic meniscus surgery.

CONCLUSION

A total of 95(81.19%) patients in total were satisfied with their health status at follow up, however, we found that arthroscopy as a treatment for meniscal tear have a relatively better mid-term clinical outcome for traumatic meniscal tears compare to non-traumatic/degenerative meniscal tears.

A comparison of stress in cracked fibrous tissue specimens with varied crack location, loading, and orientation using finite element analysis

Cracks in fibrous soft tissue, such as intervertebral disc annulus fibrosus and knee meniscus, cause pain and compromise joint mechanics. A crack concentrates stress at its tip, making further failure and crack extension (fracture) more likely. Ex vivo mechanical testing is an important tool for studying the loading conditions required for crack extension, but prior work has shown that it is difficult to reproduce crack extension. Most prior work used edge crack specimens in uniaxial tension, with the crack 90° to the edge of the specimen. This configuration does not necessarily represent the loading conditions that cause in vivo crack extension. To find a potentially better choice for experiments aiming to reproduce crack extension, we used finite element analysis to compare, in factorial combination, (1) center crack vs. edge crack location, (2) biaxial vs. uniaxial loading, and (3) crack-fiber angles ranging from 0° to 90°. The simulated material was annulus fibrosus fibrocartilage with a single fiber family. We hypothesized that one of the simulated test cases would produce a stronger stress concentration than the commonly used uniaxially loaded 90° crack-fiber angle edge crack case. Stress concentrations were compared between cases in terms of fiber-parallel stress (representing risk of fiber rupture), fiber-perpendicular stress (representing risk of matrix rupture), and fiber shear stress (representing risk of fiber sliding). Fiber-perpendicular stress and fiber shear stress concentrations were greatest in edge crack specimens (of any crack-fiber angle) and center crack specimens with a 90° crack-fiber angle. However, unless the crack is parallel to the fiber direction, these stress components alone are insufficient to cause crack opening and extension. Fiber-parallel stress concentrations were greatest in center crack specimens with a 45° crack-fiber angle, either biaxially or uniaxially loaded. We therefore recommend that the 45° center crack case be tried in future experiments intended to study crack extension by fiber rupture.

Self-Reduction of Displaced Bucket-Handle Medial Meniscal Tear in a 71-Year-Old Patient: A Case Report

Background:

Bucket-handle meniscal tears are rare in geriatric patients. Displaced bucket-handle meniscal tears are usually treated operatively. Due to the rarity of these tears in elderly patients and conflicting evidence regarding the use of arthroscopy versus conservative treatment, it is valuable to report the clinical presentation, treatment, and outcome of these injuries in elderly patients.

Case Description:

We describe a 71-year-old man who presented with an acute, displaced, magnetic resonance imaging (MRI)-confirmed right medial meniscal bucket-handle tear with mild effusion and no signs of degenerative joint disease. On physical examination, the patient was unable to fully extend the right leg due to locking of the knee. At 2-month follow-up, MRI showed mild degenerative changes and an anatomically reduced tear. At 6-month follow-up, the patient reported normal, pain-free knee function, and MRI showed the tear healing in anatomic position with minimal inferior surface changes and no effusion. He returned to his pain-free baseline level of physical activity.

Literature Review:

Upon review of the English literature, this 71-year-old patient is an exceptional case and one of the oldest patients reported to have sustained a displaced medial meniscal bucket-handle tear treated successfully with nonoperative means. Two reported cases of spontaneously reduced meniscal bucket-handle tears were found in the English literature, although both cases were seen in much younger males and involved the lateral meniscus.

Clinical Relevance:

This case suggests that in elderly patients with displaced medial meniscus bucket-handle tears that reduce spontaneously, the physician can safely and efficaciously use conservative, nonoperative management to achieve restoration of baseline knee function and anatomic meniscal healing while avoiding the risks of arthroscopic surgery. Surgical intervention for reduction without repair may be an available option, but no literature is present to direct care; however, complete documentation as in the current case would be instructive. Katz et al have reported that physical therapy was as efficacious as surgical intervention, although the specific displaced bucket-handle tear was not reported.

Gender Effect on the Outcome of Partial Medial Meniscectomy

Complex posterior horn tears of the medial meniscus are common. Previous reports performed statistical stratifications to address the influence of gender on outcome following arthroscopic partial medial meniscectomy with variable conclusions. The aim of this study was to compare the clinical results of arthroscopic partial meniscectomy of the knee between men and women with complex medial meniscal tear type while controlling for other variables that may affect outcome. This study compared groups of 86 men and 49 women who were followed prospectively using the Lysholm Knee Scoring Scale, the visual analogue scale, and patient's satisfaction. Mean age at operation was 51 years and mean follow-up was 26 months. Mean Lysholm score improved from 69 preoperatively to 82.1 postoperatively (P<.001) in the male group and from 64.2 preoperatively to 73.5 postoperatively (P=.04) in the female group. At last follow-up, 68 (79%) men and 35 (71%) women stated that they were satisfied with the operation. In both groups, the severity of chondral lesions was found to be negatively correlated to the preoperative score. Women had more severe chondral lesions at arthroscopy than men. This comparative study showed no significant difference between men and women in terms of clinical improvement following arthroscopic partial meniscectomies of complex tear types in stable knees with intact lateral meniscus. Women had lower functionality pre- and postoperatively, which correlated with more severe chondral degeneration at surgery compared with men.

Effect of posterior cruciate ligament rupture on the radial displacement of lateral meniscus

BACKGROUND

The relationship between lateral meniscus tear and posterior cruciate ligament injury is not well understood. The present study aims to investigate and assess the effect of posterior cruciate ligament rupture on lateral meniscus radial displacement at different flexion angles under static loading conditions.

METHODS

Twelve fresh human cadaveric knee specimens were divided into four groups such as posterior cruciate ligament intact, anterolateral band rupture, posteromedial band rupture and posterior cruciate ligament complete rupture groups, according to the purpose and order of testing. Radial displacement of lateral meniscus was measured under different loads (200-1000N) at 0°, 30°, 60°, and 90° of knee flexion.

FINDINGS

Compared with posterior cruciate ligament intact group, the displacement values of lateral meniscus in anterolateral band rupture group increased at 0° flexion with 600N, 800N, and 1000N and at 30°, 60° and 90° flexion under all loading conditions. Posteromedial band rupture group exhibited higher displacement at 0° flexion under all loading conditions, at 30° and 60° flexion with 600, 800N and 1000N, and at 90° flexion with 400N, 600N, 800N, and 1000N than the posterior cruciate ligament intact group. The posterior cruciate ligament complete rupture group had a higher displacement value of lateral medial meniscus at 0°, 30°, 60° and 90° flexion under all loading conditions, as compared to the posterior cruciate ligament intact group.

INTERPRETATION

The study concludes that partial and complete rupture of the posterior cruciate ligament can trigger the increase of radial displacement on lateral meniscus.

In vivo cartilage strain increases following medial meniscal tear and correlates with synovial fluid matrix metalloproteinase activity

Meniscal tears are common injuries, and while partial meniscectomy is a frequent treatment option, general meniscus loss is a risk factor for the development of osteoarthritis. The goal of this study was to measure the in vivo tibiofemoral cartilage contact patterns in patients with meniscus tears in relation to biomarkers of cartilage catabolism in the synovial fluid of these joints. A combination of magnetic resonance imaging and biplanar fluoroscopy was used to determine the in vivo motion and cartilage contact mechanics of the knee. Subjects with isolated medial meniscus tears were analyzed while performing a quasi-static lunge, and the contralateral uninjured knee was used as a control. Synovial fluid was collected from the injured knee and matrix metalloproteinase (MMP) activity, sulfated glycosaminoglycan, cartilage oligomeric matrix protein, prostaglandin E2, and the collagen type II cleavage biomarker C2C were measured. Contact strain in the medial compartment increased significantly in the injured knees compared to contralateral control knees. In the lateral compartment, the contact strain in the injured knee was significantly increased only at the maximum flexion angle (105°). The average cartilage strain at maximum flexion positively correlated with total MMP activity in the synovial fluid. These findings show that meniscal injury leads to loss of normal joint function and increased strain of the articular cartilage, which correlated to elevated total MMP activity in the synovial fluid. The increased strain and total MMP activity may reflect, or potentially contribute to, the early development of osteoarthritis that is observed following meniscal injury.

Ultrasonographic findings in a large series of patients with knee pain

Background:

Musculoskeletal ultrasound (MSKUS) is becoming more and more popular in the evaluation of different musculoskeletal abnormalities. The aim of this retrospective study was to document the prevalence and spectrum of MSKUS findings at the painful knee.

Materials and Methods:

All the studies of MSKUS that were performed for the evaluation of knee pain during the previous 2 years at the Department of Radiology in Nazareth hospital were reviewed. Demographic and clinical parameters including age, gender, side, and MSKUS findings were documented.

Results:

Two hundred and seventy-six patients were included in the review. In 21 of them, both knees were evaluated at the same setting (total number of knees evaluated was 297). One hundred and forty-four knees were of the left side. Thirty-three pathologies were identified. 34% of the studies were negative. The most common MSKUS findings were medial meniscal tear (MMT) (20%), Baker's cyst (BC) (16%), and osteoarthritis (OA) (11%). Only one knee of all the knees evaluated in our study showed synovitis. Fifty-three knees (18% of all the knees evaluated) had more than one imaging finding, mosty two and while some had three findings. The most common combination of findings was MMT and BC (8 knees), MMT with OA (8 knees), and MMT with fluid (6 knee). In 67% of the patients who had simultaneous bilateral knee evaluation, at least one knee had no abnormal findings and in 43%, both knees were negative.

Conclusions:

MSKUS has the potential for revealing huge spectrum of abnormalities. In nearly 90% of the positive studies, degenerative/mechanical abnormalities were reported, with MMT, BC, and osteoarthritic changes being the most common.

The human meniscus: a review of anatomy, function, injury, and advances in treatment

Meniscal injuries are recognized as a cause of significant musculoskeletal morbidity. The menisci are vital for the normal function and long-term health of the knee joint. The purpose of this review is to provide current knowledge regarding the anatomy and biomechanical functions of the menisci, incidence, injury patterns and the advancements in treatment options of meniscal injury. A literature search was performed by a review of PubMed, Google Scholar, MEDLINE, and OVID for all relevant articles published between 1897 and 2014. This study highlights the anatomical and biomechanical characteristics of the menisci, which may be relevant to injury patterns and treatment options. An understanding of the normal anatomy and biomechanical functions of the knee menisci is a necessary prerequisite to understanding pathologies associated with the knee.

The effectiveness of electromyographic biofeedback as part of a meniscal repair rehabilitation programme

The objective of the study was to assess the effectiveness of using electromyographic biofeedback in the early stages of rehabilitation after meniscal repair. In this randomised, controlled, parallel group study, the evolution of patients with meniscal lesions treated by meniscal suture who received (study group, n = 33) or did not receive (control group, n = 31) electromyographic biofeedback as part of their early rehabilitation programme has been compared. A total of 64 patients with previous meniscal repair participated in the study. The patients received a baseline assessment (after 1 postoperative week) and a follow-up (after 8 postoperative weeks) consisting of surface electromyography, dynamometry of thigh muscles and the assessment of the Knee injury and Osteoarthritis Outcome Score (KOOS). The electrical potential in contraction and the speed for contraction and relaxation for all monitored muscles increased significantly in the study group (p < 0.05). The difference between groups in the assessed score was significant for sport and recreational function (p < 0.05). The strength of the thigh muscles was not significantly influenced by the introduction of electromyographic biofeedback (EMG- BFB) in the rehabilitation programme. Electromyographic biofeedback helped patients to control their muscles after meniscal repair to accomplish physical activities that require better neuromuscular coordination and control. For these reasons, one may consider electromyographic biofeedback as an important component of rehabilitation after meniscal repair. Key PointsExercises during the early phases of rehabilitation after meniscal repair are difficult to perform because of pain, oedema, and possibly a disruption in normal joint receptor activity.Electromyographic biofeedback is a painless, non-invasive method that can be used in muscle recovery after meniscal repair and enhances the rehabilitation process, especially related to muscular function.The rehabilitation programme that includes electromyographic biofeedback after meniscal repair increased the speed of muscle response to acoustic stimulation in both the initiation of contraction (onset time) and relaxation (offset time) and, also, the capacity of performing some specific physical acti-vities after 8 weeks of rehabilitation (according to KOOS values).Electromyographic biofeedback is not responsible for the decrease in pain, swelling or other postoperative symptoms but it is important in order to help the patient to conduct the activities which require neuromuscular coordination and muscle control.