An Up-to-Date Review of the Meniscus Literature: A Systematic Summary of Systematic Reviews and Meta-analyses

Survey Results Concerning Current Trends in Meniscus Repair Indications and Preferences from Members of the Pediatric Research in Sports Medicine (PRiSM) Society

Meniscus repair has increased in frequency, especially among surgeons who focus on youth sports injuries. The aim of this study was to determine current trends in meniscus repair among a specific subset of meniscus repair surgeons. A cross-sectional survey utilizing several clinical vignettes was administered to orthopaedic surgeon members of the Pediatric Research in Sports Medicine (PRiSM) Society to investigate surgeon experience and training, number of meniscus repair procedures performed, and surgical and rehabilitation preferences. A statistical analysis of the responses was performed to determine associations between years in practice or type of fellowship training and the number of meniscus repair procedures performed, surgical indications, and rehabilitation preferences. The response rate to various questions ranged from 61.5 (59/96) to 63.5% (61/96). In all vignettes, a majority favored repair as well as some degree of weight-bearing and range-of-motion restrictions. Surgeons who had been in practice for 6 to 10 years performed significantly more meniscus repairs per year than those who had been in practice for greater than 20 years (p = 0.009) and those who had been in practice for 0 to 5 years (p = 0.05). Surgeons who had been in practice for greater than 20 years performed a significantly higher percentage of meniscectomies relative to meniscus repairs, compared with those in practice for 0 to 5 years (p = 0.002) or 6 to 10 years (p = 0.0003). When surgeons were grouped into those with less than 10 years of experience and those with greater than 10 years of experience, the former group performed a significantly higher number of meniscus repairs relative to meniscectomies than the latter group of surgeons (p < 0.0001). Less experienced surgeons are more likely to perform meniscus repair than meniscectomy, but all surgeons surveyed had a general preference for repair in all clinical vignettes. Repair technique preferences as well as rehabilitation protocols varied widely among surgeons.

Addressing meniscal deficiency part 1: An umbrella review of systematic reviews and meta-analyses on meniscal allograft transplantation

Purpose

Meniscal injuries are common in the young and active population. There is increasing utilization of surgical interventions like meniscal allograft transplantation (MAT) to restore the protective function of menisci following injury leading to meniscal deficiency. Extensive research and publications exist on the management of meniscal injury and the sequalae of meniscal deficiency. However, a comprehensive synthesis of the existing evidence through an umbrella review is lacking. This study aims to fill this gap by providing a current examination of the literature on MAT.

Methods

A comprehensive search was conducted in the MEDLINE, Embase and Scopus databases to identify relevant systematic reviews and meta-analyses. Studies were screened based on predefined inclusion and exclusion criteria. The quality of the included studies was assessed using the AMSTAR-2 tool.

Results

A total of 41 studies were included in the review, with most published within the last decade. The majority of studies (56.1%) received a 'Critically Low' confidence rating, 26.8% were rated as 'Low', and only 14.6% were rated as 'High' confidence. From the included studies, 51.2% reported on PROMs, with the Lysholm score being the most common. Transplant failure and reoperation rate were reported in 34.1% and 19.5% of studies respectively. Studies on MAT reported favourable short-term outcomes in terms of patient-reported outcome measures (PROMs) but were limited by the lack of randomized control trials and consistent comparison groups.

Conclusions

This umbrella review highlights an increase in interest in MAT but underscores the need for higher-quality reviews with standardized reporting and rigorous methodologies. Future research should focus on long-term outcomes, optimal surgical techniques, patient selection criteria and risk factors for transplant failure. There is also a need for more studies focusing on MAT in pediatric populations. Overall, this review provides a comprehensive assessment of the current state of research in MAT and identifies areas for improvement in future studies.

Level of Evidence

Level IV.

Meniscal Allograft versus Synthetic Graft in Treatment Outcomes of Meniscus Repair: A Mini-review and Meta-analysis

Meniscal injuries are highly correlated with osteoarthritis (OA) onset and progression. Although meniscal allograft transplantation (MAT) is a therapeutic option to restore meniscal anatomy, a shortage of donor material and the donor-derived infectious risk may be concerns in clinics. This review summarizes the literature reporting meniscus repair status in preclinical models and clinical practice using allografts or synthetic grafts. The advantages and limitations of biodegradable polymer-based meniscal scaffolds, applied in preclinical studies, are discussed. Then, the long-term treatment outcomes of patients with allografts or commercial synthetic scaffolds are compared. A total of 47 studies are included in our network meta-analysis. Compared with the meniscal allografts, the commercial synthetic products significantly improved clinical treatment outcomes in terms of the Knee Injury and Osteoarthritis Outcome Score (KOOS), Visual Analog Scale (VAS) scores, and Lysholm scores. In addition, development strategies for the next generation of novel synthetic scaffolds are proposed through optimization of structural design and fabrication, and selection of cell sources, external stimuli, and active ingredients. This review may inspire researchers and surgeons to design and fabricate clinic-orientated grafts with improved treatment outcomes.

Meniscus Tears in Elite Athletes: Treatment Considerations, Clinical Outcomes, and Return to Play

PURPOSE OF REVIEW

Management of meniscal injuries in the elite athlete is a difficult problem secondary to the high demands of athletic competition, the need for a timely return to sport, and the desire to maximize performance over time. The purpose of this review is to provide an up-to-date summary on the current literature and trends regarding the management of meniscus injuries with a special consideration for elite athletes.

RECENT FINDINGS

Historically, partial meniscectomy has been the primary treatment option for meniscus injuries. However, in recent years there has been an increased emphasis on meniscus preservation due to the increased risk of cartilage degeneration over time. Moreover, while partial meniscectomy still provides a quicker return to sport (RTS), recent literature has demonstrated similar rates of RTS and return to pre-injury levels between partial meniscectomy and meniscus repair. In the setting of symptomatic meniscal deficiency, meniscus allograft transplantation has become an increasingly utilized salvage procedure with promising yet variable outcomes on the ability to withstand elite competition. Currently, there is no uniform approach to treating meniscal injuries in elite athletes. Therefore, an individualized approach is required with consideration of the meniscus tear type, location, concomitant injuries, athlete expectations, rehabilitation timeline, and desire to prevent or delay knee osteoarthritis. In athletes with anatomically repairable tears, meniscus repair should be performed given the ability to restore native anatomy, provide high rates of RTS, and mitigate long-term chondral damage. However, partial meniscectomy can be indicated for unrepairable tears.

Management of Meniscus Pathology with Concomitant Anterior Cruciate Ligament Injury

PURPOSE OF REVIEW

The purpose of this review is to summarize current clinical knowledge on the prevalence and types of meniscus pathology seen with concomitant anterior cruciate ligament (ACL) injury, as well as surgical techniques, clinical outcomes, and rehabilitation following operative management of these pathologies.

RECENT FINDINGS

Meniscus pathology with concomitant ACL injury is relatively common, with reports of meniscus pathology identified in 21-64% of operative ACL injuries. These concomitant injuries have been associated with increased age and body mass index. Lateral meniscus pathology is more common in acute ACL injury, while medial meniscus pathology is more typical in chronic ACL deficiency. Meniscus tear patterns associated with concomitant ACL injury include meniscus root tears, lateral meniscus oblique radial tears of the posterior horn (14%), and ramp lesions of the medial meniscus (8-24%). These meniscal pathologies with concomitant ACL injury are associated with increased rotational laxity and meniscal extrusion. There is a paucity of comparative studies to determine the optimal meniscus repair technique, as well as rehabilitation protocol, depending on specific tear pattern, location, and ACL reconstruction technique. There has been a substantial increase in recent publications demonstrating the importance of meniscus repair at the time of ACL repair or reconstruction to restore knee biomechanics and reduce the risk of progressive osteoarthritic degeneration. Through these studies, there has been a growing understanding of the meniscus tear patterns commonly identified or nearly missed during ACL reconstruction. Surgical management of meniscal pathology with concomitant ACL injury implements the same principles as utilized in the setting of isolated meniscus repair alone: anatomic reduction, biologic preparation and augmentation, and circumferential compression. Advances in repair techniques have demonstrated promising clinical outcomes, and the ability to restore and preserve the meniscus in pathologies previously deemed irreparable. Further research to determine the optimal surgical technique for specific tear patterns, as well as rehabilitation protocols for meniscus pathology with concomitant ACL injury, is warranted.

Knee Arthroscopic Surgery in Middle-Aged Patients With Meniscal Symptoms: A 10-Year Follow-up of a Prospective, Randomized Controlled Trial

BACKGROUND

Short- and midterm evaluations of arthroscopic meniscal surgery have shown little or no effect in favor of surgery, although long-term effects, including radiographic changes, are unknown.

PURPOSE

To compare the 10-year outcomes in middle-aged patients with meniscal symptoms between a group that received an exercise program alone and a group that received knee arthroscopy in addition to the exercise program with respect to the prevalence of radiographic and symptomatic osteoarthritis (OA), patient-reported outcomes, and clinical status.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Of 179 eligible patients aged 45 to 64 years, 150 were randomized to undergo either 3 months of exercise therapy (nonsurgery group) or knee arthroscopy in addition to the exercise therapy (surgery group). Surgery usually consisted of partial meniscectomy (n = 56) or diagnostic arthroscopy (n = 8). Radiographs were assessed according to the Kellgren-Lawrence score at the baseline and 5- and 10-year follow-ups. Patient-reported outcome measures were reported at the baseline and 1-, 3-, 5-, and 10-year follow-ups. Clinical status was assessed at a 10-year follow-up. The primary outcomes were radiographic OA and changes in the Knee injury and Osteoarthritis Outcome Score Pain subscale (KOOSPAIN) from the baseline to the 10-year follow-up. The primary analysis was performed using the intention-to-treat approach.

RESULTS

At the time of the 10-year follow-up, eight patients had died, leaving 142 eligible patients. Radiographic OA was assessed for 95 patients (67%), questionnaires were answered by 110 (77%), and the clinical status was evaluated for 95 (67%). Radiographic OA was present in 67% of the patients in each group (P≥ .999); symptomatic OA was present in 47% of the nonsurgery group and 57% of the surgery group (P = .301). There were no differences between groups regarding changes from baseline to 10 years in any of the KOOS subscales.

CONCLUSION

Knee arthroscopic surgery, in most cases consisting of partial meniscectomy or diagnostic arthroscopy, in addition to exercise therapy in middle-aged patients with meniscal symptoms, did not increase the rates of radiographic or symptomatic OA and resulted in similar patient-reported outcomes at the 10-year follow-up compared with exercise therapy alone. Considering the short-term benefit and no long-term harm from knee arthroscopic surgery, the treatment may be recommended when first-line treatment-including exercise therapy for ≥3 months-does not relieve patient's symptoms.

REGISTRATION

Clinical Trials NCT01288768 (ClinicalTrials.gov identifier).

Addressing meniscal deficiency part 2: An umbrella review of systematic reviews and meta-analyses on meniscal scaffold-based approaches

Purpose

Meniscal injuries are common in knee surgery and often require preservation techniques to prevent secondary osteoarthritis. Despite advancements in repair techniques, some patients undergo partial meniscectomy, which can lead to postmeniscectomy syndrome. To address these challenges, meniscal substitution techniques like scaffolds have been developed. However, a comprehensive synthesis of the existing evidence through an umbrella review is lacking.

Methods

A comprehensive search was conducted in the MEDLINE, Embase and Scopus databases to identify relevant systematic reviews and meta-analyses. Studies were screened based on predefined inclusion and exclusion criteria. The quality of included studies was assessed using the AMSTAR-2 tool.

Results

A total of 17 studies met the inclusion criteria and were included in the review. Most studies focused on the use of collagen-based scaffolds, with fewer studies evaluating synthetic scaffolds. The majority of studies (52.9%) were rated as having 'Critically Low' overall confidence, with only one study (5.9%) rated as 'High' confidence and most studies exhibiting methodological limitations, such as small sample sizes and lack of long-term follow-up. Despite these limitations, the majority of studies reported positive short-term outcomes, including pain relief and functional improvement, following scaffold implantation. However, some studies noted a relatively high failure rate. Radiographically, outcomes also varied, with some studies reporting morphological deterioration of the implant seen on MRI, while others noted possible chondroprotective effects.

Conclusions

Meniscal scaffold-based approaches show promise in the management of meniscal deficiency; however, the current evidence is limited by methodological shortcomings. One notable gap in the literature is the lack of clear guidelines for patient selection and surgical technique. Future research should focus on conducting well-designed randomized controlled trials with long-term follow-up to further elucidate the benefits and indications of these techniques in clinical practice. Additionally, efforts should be made to develop consensus guidelines to standardize the use of meniscal scaffolds and improve patient outcomes. Despite limited availability, synthesizing the literature on meniscal scaffold-based approaches is crucial for understanding research, guiding clinical decisions and informing future directions.

Level of Evidence

Level IV.

Outcome of meniscal repairs in paediatric population: A tertiary centre experience

BACKGROUND

Meniscal sparing surgery is a widely utilised treatment option for unstable meniscal tears with the aim of minimising the risk of progression towards osteoarthritis. However, there is limited data in the literature on meniscal repair outcomes in skeletally immature patients.

AIM

To evaluate the re-operation rate and functional outcomes of meniscal repairs in children and adolescents.

METHODS

We performed a retrospective review of all patients who underwent arthroscopic meniscal repair surgery between January 2007 and January 2018. All patients were under the age of 18 at the time of surgery. Procedures were all performed by a single surgeon. Information was gathered from our hospital Electronic Patient Records system. The primary outcome measure was re-operation rate (need for further surgery on the same meniscus). Secondary outcome measures were surgical complications and patient reported outcome measures that were International Knee Documentation Committee (IKDC), Tegner and Lysholm scores.

RESULTS

We identified 59 patients who underwent 66 All-inside meniscal repairs (32 medial meniscus and 34 Lateral meniscus). Meniscal repairs were performed utilizing FasT-Fix (Smith and Nephew) implants. There were 37 males and 22 females with an average age of 14 years (range 6-16). The average follow-up time was 53 months (range 26-140). Six patients had concomitant anterior cruciate ligament reconstruction surgery along with the meniscal repair. There were no intra-operative complications. The re-operation rate for meniscal repairs was 16.6% (11 cases) with 2 patients requiring further meniscal repairs and 9 patients underwent partial meniscectomies. The mean postoperative IKDC score was 88 (44-100), Tegner score was 7(2-10) and Lysholm score was 94 (57-100).

CONCLUSION

Our results showed that arthroscopic repair of meniscal tears in the paediatric population is an effective treatment option that has a low failure rate and good postoperative clinical with the advantage of preserving meniscal tissues.

Trends in Meniscus-Related Publications in PubMed Since 1928: A Bibliometric Study

Background

As information on the meniscus accumulates in PubMed, it is possible to evaluate the trends in research on the topic over time.

Purpose

To evaluate the major trends in meniscus-related publications in PubMed from the earliest publication to the present day.

Study Design

Cross-sectional study.

Methods

PubMed was searched on January 3, 2023, using the search strategy "menisc *"[All Fields] AND ("knee"[MeSH Terms] OR "knee"[All Fields] OR "knee joint"[MeSH Terms] OR ("knee"[All Fields] AND "joint"[All Fields]) OR "knee joint"[All Fields]) AND 1900/01/01:2022/12/31[Date - Publication]. This retrieved 15,569 human and animal studies. We determined the top 10 meniscus-related publications in terms of overall citations and citations per year, as well as the top 10 authors, journals, countries, and institutions of cited publications on the meniscus. In addition, we performed word-cloud analyses based on meniscus-related terms from different periods (before 1981, before 2000, after 2005, and in the past 5 years [2018-2022]), including the year of first appearance and the number of publications featured.

Results

Since the first recorded publication on the meniscus in 1928, there was a steady growth in the number of articles until 2005, when there was an upsurge in publications from 254 in 2005 to 955 in 2022. Noyes was the author with the most citations (n = 3314), and a 2006 study by Caplan and Dennis had the most citations per year (n = 125). Arthroscopy published the most articles on the meniscus with 1118, whereas the Journal of Cellular Biochemistry had the most citations per article with 125.69. The most published countries and institutes were the United States and the Hospital for Special Surgery, respectively. Word-cloud analysis of article titles showed that "meniscectomy" had become less prominent, and "root,""ramp,""transplantation," and "slope" had become more prominent.

Conclusion

There has been an upsurge in publications on the meniscus since 2005, with word-cloud analysis indicating shifting interests in meniscus-related research.

A bibliometric and visualized analysis of meniscus suture based on the WOS core collection from 2010 to 2022: A review

Meniscus suture is an important treatment method for meniscus injury and contributes to the preservation of proprioception, restoration of knee biomechanics and alleviation of progressive osteoarthritis. However, there are few visualized analyses concerning the present studies of meniscus suture. This paper aims to evaluate the global trends, highlights and frontiers of meniscus suture. A bibliometric analysis was conducted based on the results of studies related to meniscus suture from web of science core collection. VOSviewer, GraphPad Prism, Microsoft Excel and R-bibliometrix were utilized for the bibliometric analysis of country and institution distribution, chronological distribution, source journals analysis, prolific authors and institutions analysis, keywords analysis, and reference co-citation analysis. A total of 950 publications on meniscus suture from 177 different sources were retrieved over the set time span. These publications were completed by 3177 authors from 1112 institutions in 54 countries. The United States was the most prolific country with 7960 citations and 348 publications (36.63%). Furumatsu Takayuki acted as the most prolific author (51 publications), while Robert F LaPrade with 1398 citations was the most-cited author. And more papers were published in the core journals, including American Journal of Sports Medicine, Arthroscopy-The Journal of Arthroscopic and Related Surgery, Knee Surgery Sports Traumatology Arthroscopy and Arthroscopy Techniques. Furthermore, "meniscus healing," "meniscus root tear" seem to be the emerging research hotspots. Notably, the publication trend concerning the all-inside suture technique has been rising during the past decade. The number of research publications on meniscus suture has been continuously risen since 2010. The authors, publications and institutions from the United States and East Asia were still the mainstays in this field. And the all-inside suture may become the mainstream surgical technique in the future, with meniscus healing and meniscus root tears being research highlights recently.

Meniscus Allograft Transplantation Augmented With Autologous Bone Marrow Aspirate Concentrate

Meniscus allograft transplantation (MAT) has been shown to be a feasible surgical option for younger patients, below 50 years of age who have meniscal insufficiency and have failed conservative treatment measures. In this technical note, we describe a procedure of harvesting and injecting bone marrow aspirate concentrate in a meniscus allograft during a MAT procedure, which may allow for longer lasting transplants and improve patient outcomes. In this technical note, bone marrow aspirate concentrate is harvested arthroscopically from the intercondylar notch at the surgical site, which prevents additional donor site morbidity, as seen with harvesting from other locations, such as the iliac crest. This also reduces operating time, since harvesting from the iliac crest requires different patient positioning and usually additional anesthesia. The authors of this surgical technique believe that biological augmentation during MATs will assist surgeons in maximizing graft survivorship and, ultimately, lead to better patient outcomes.

Meniscal Extrusion: Diagnosis, Etiology, and Treatment Options

PURPOSE OF REVIEW

The concept of meniscal extrusion has recently been recognized as a hallmark of meniscus dysfunction. This review examines contemporary literature regarding the pathophysiology, classification, diagnosis, treatment, and future directions for investigation regarding meniscus extrusion.

RECENT FINDINGS

Meniscus extrusion, defined as >3 mm of radial displacement of the meniscus, leads to altered knee biomechanics and accelerated knee joint degeneration. Meniscus extrusion has been associated with degenerative joint disease, posterior root and radial meniscal tears, and acute trauma. Meniscus centralization and meniscotibial ligament repair have been proposed as techniques to address meniscal extrusion with promising biomechanical, animal model, and early clinical reports. Further studies on the epidemiology of meniscus extrusion and associated long-term nonoperative outcomes will help to elucidate its role in meniscus dysfunction and resultant arthritic development. Understanding and appreciation for the anatomic attachments of the meniscus will help to inform future repair techniques. Long-term reporting on the clinical outcomes of meniscus centralization techniques will yield insights into the clinical significance of meniscus extrusion correction.

High quality rehabilitation to optimize return to sport following lateral meniscus surgery in football players

There is a paucity of studies in the literature pertaining about how to guide rehabilitation and return to sport (RTS) progression for football players that have sustained a lateral meniscus injury and subsequent surgery. These patients are clinically challenging. If they return to sport too soon, before the rehabilitation process is completed and RTS criteria have been met, functional outcomes could be non-optimal and/or associated with higher reinjury risk. The aims of this paper are (I) to provide a brief overview of the current trends in acute lateral meniscus tears surgery in football players and (II) to suggest a framework for clinicians on how to progress the player following lateral meniscus surgery. Post-operative rehabilitation approaches are different for meniscus repair and for the other surgical techniques. The main goal of all involved practitioners should be to balance the "short term success" with the "long term protection" of the athlete's health. Specific key goals and interventions in early-, mid-, and late-stage rehabilitation are provided. The most important principle is to manage the progressive increase in loading through multiple measurements including frequent medical control consultations and functional tests detailing movement quantity and quality. RTS monitoring needs to be comprehensive and interdisciplinary, incorporating state of the art tests, to achieve recovery of sport-specific fitness, optimal movement quality and on-field rehabilitation progression.

Post-traumatic knee osteoarthritis; the role of inflammation and hemarthrosis on disease progression

Knee injuries such as anterior cruciate ligament ruptures and meniscal injury are common and are most frequently sustained by young and active individuals. Knee injuries will lead to post-traumatic osteoarthritis (PTOA) in 25–50% of patients. Mechanical processes where historically believed to cause cartilage breakdown in PTOA patients. But there is increasing evidence suggesting a key role for inflammation in PTOA development. Inflammation in PTOA might be aggravated by hemarthrosis which frequently occurs in injured knees. Whereas mechanical symptoms (joint instability and locking of the knee) can be successfully treated by surgery, there still is an unmet need for anti-inflammatory therapies that prevent PTOA progression. In order to develop anti-inflammatory therapies for PTOA, more knowledge about the exact pathophysiological mechanisms and exact course of post-traumatic inflammation is needed to determine possible targets and timing of future therapies.

Treatment strategies for meniscal lesions: from past to prospective therapeutics

Menisci play an important role in the biomechanics of knee joint function, including loading transmission, joint lubrication, prevention of soft tissue impingement during motion and joint stability. Meniscal repair presents a challenge due to a lack of vascularization that limits the healing capacity of meniscal tissue. In this review, the authors aimed to untangle the available treatment options for repairing meniscal tears. Various surgical procedures have been developed to treat meniscal tears; however, clinical outcomes are limited. Consequently, numerous researchers have focused on different treatments such as the application of exogenous and/or autologous growth factors, scaffolds including tissue-derived matrix, cell-based therapy and miRNA-210. The authors present current and prospective treatment strategies for meniscal lesions.

No evidence in support of arthroscopic partial meniscectomy in adults with degenerative and nonobstructive meniscal symptoms: a level I evidence-based systematic review

PURPOSE

It is unclear whether the results of arthroscopic partial meniscectomy (APM) are comparable to a structured physical therapy (PT). This systematic review investigated efficacy of APM in the management of symptomatic meniscal damages in middle aged patients. Current available randomised controlled trials (RCTs) which compared APM performed in isolation or combined with physical therapy versus sham arthroscopy or isolated physical therapy were considered in the present systematic review.

METHODS

This systematic review was conducted according to the 2020 PRISMA statement. All the level I RCTs which investigated the efficacy of AMP were accessed. Studies which included elderlies with severe OA were not eligible, nor were those in which APM was combined with other surgical intervention or in patients with unstable knee or with ligaments insufficiency. The risk of bias was assessed using the software Review Manager 5.3 (The Nordic Cochrane Collaboration, Copenhagen). To rate the quality of evidence of collected outcomes, the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used.

RESULTS

Data from 17 studies (2037 patients) were collected. 48.5% (988 of 2037 patients) were women. The mean age of the patients was 52.7 ± 3.9 years, the mean BMI 27.0 ± 1.3 kg/m². The current evidence suggests no difference in functional PROMs (quality of the evidence: high), clinical PROMs (quality of the evidence: high), pain (quality of the evidence: high), quality of life (quality of the evidence: high), physical performance measures (quality of the evidence: moderate), and OA progression (quality of the evidence: moderate).

CONCLUSIONS

The benefits of APM in adults with degenerative and nonobstructive meniscal symptoms are limited. The current evidence reports similarity in the outcome between APM and PT. Further long-term RCTs are required to investigate whether APM and PT produce comparable results using validated and reliable PROMs. Moreover, future RCTs should investigate whether patients who might benefit from APM exist, clarifying proper indications and outcomes. High quality investigations are strongly required to establish the optimal PT regimes.

LEVEL OF EVIDENCE

Level I.

Meniscal Tear Management Associated with ACL Reconstruction

Meniscal lesions often occur in association with anterior cruciate ligament (ACL) tears at the moment of the injury or, secondarily, as a consequence of knee instability. Both ACL and meniscus lesions are associated with a higher risk of osteoarthritis. Adequate treatment of these lesions reduces the rate of degenerative changes in the affected knee. Meniscal tears should be addressed concomitantly with ACL reconstruction and the treatment must be oriented towards preserving the meniscal tissue anytime this is possible. Several options for approaching a meniscus tear are available. The meniscal suture should always be considered, and, if possible, meniscectomy should be the last choice. “Masterly neglect” is a valuable option in selected cases.

Inside-Out Approach to Meniscus Repair: Still the Gold Standard?

PURPOSE OF REVIEW

The purpose of this review is to provide an up-to-date summary on the current literature and trends regarding use of the inside-out approach to meniscus repair. Additionally, the paper describes the authors preferred techniques for inside-out meniscus repair utilizing posteromedial and posterolateral exposures.

RECENT FINDINGS

There has been a substantial increase in recent publications regarding meniscus repair. However, comparisons regarding the optimal repair technique have not been conclusive. Despite the recent increase in use of all-inside devices, multiple investigations with short-to-mid-term follow-up have demonstrated similar rates of meniscus healing between inside-out and all-inside repair techniques. Similarly, current literature describes comparable failure rates of around 20%. There are variations in the profile of complications, with all-inside devices having more implant-related complications and inside-out techniques with higher neurovascular injuries. Inside-out meniscus repair is a versatile, cost-effective technique that remains the gold standard for management of most meniscus tear patterns. Through a thoughtful approach, efficient suture retrieval and repair can be performed while protecting critical neurovascular structures. All-inside meniscus repair devices have increased in popularity and surgeon access, but this technique is not without limitations and comparisons to inside-out meniscus repair demonstrates equivocal outcomes.

Biomechanics of the lateral meniscus: evidences from narrative review

Lateral meniscus plays a crucial role in the knee stability and function. Although complex settings are required for lateral meniscus biomechanical assessment, such characteristics have been investigated over time to optimize the daily clinical practice surgical procedure. The aim of the present study was to provide an overview of literature knowledge regarding the biomechanics of lateral meniscus and give further insights about novel experimental analyses. Studies regarding lateral meniscus mobility, effect on knee laxity, and contact mechanics were included in the review. The effect of meniscal lesion, meniscal repair, partial meniscectomy, and meniscus allograft transplantation were retrieved for either in vivo, cadaveric, or in-silico computational settings. Knee laxity was evaluated both in presence of isolated meniscal tears and in anterior cruciate ligament (ACL) deficient knees. Surgical navigation systems and robots were mainly used for the investigations in vivo and in cadaveric studies, while accelerometers emerged as an alternative for ambulatory assessments. Contact mechanics was only assessed in cadaveric and computational studies. Great effort has been put into exploring lateral meniscus biomechanics from multiple perspectives. Strong evidence emerged regarding the importance of lateral meniscus repair: increased knee stability at high degrees of knee flexion and reduction of peak contact pressures on tibial cartilage were the most reported benefits. The meniscus allograft transplantation also emerged as a concrete solution for irreparable tears and further studies are needed to investigate its long-term influence on knee stability.

Treatment of post-meniscectomy knee symptoms with medial meniscus replacement results in greater pain reduction and functional improvement than non-surgical care

PURPOSE

Partial meniscectomy is a common orthopedic procedure intended to improve knee pain and function in patients with irreparable meniscal tears. However, 6-25% of partial meniscectomy patients experience persistent knee pain after surgery. In this randomized controlled trial (RCT) involving subjects with knee pain following partial meniscectomy, it was hypothesized that treatment with a synthetic medial meniscus replacement (MMR) implant provides significantly greater improvements in knee pain and function compared to non-surgical care alone.

METHODS

In this prospective, multicenter RCT, subjects with persistent knee pain following one or more previous partial meniscectomies were randomized to receive either MMR or non-surgical care. This analysis evaluated the 1-year outcomes of this 2-year clinical trial. Patient-reported knee pain, function, and quality of life were measured using nine separate patient-reported outcomes. The primary outcomes were the pain subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS) and the average of all five KOOS subscales (KOOS Overall). Treatment cessation was defined as permanent device removal in the MMR group and any surgical procedure to the index knee in the non-surgical care group.

RESULTS

Treated subjects had a median age of 52 years old (range 30-69 years) and one or more previous partial meniscectomies at a median of 34 months (range 5-430 months) before trial entry. Among 127 subjects treated with either MMR (n = 61) or non-surgical care (n = 66), 11 withdrew from the trial or were lost to follow-up (MMR, n = 0; non-surgical care, n = 11). The magnitude of improvement from baseline to 1 year was significantly greater in subjects who received MMR in both primary outcomes of KOOS Pain (P = 0.013) and KOOS Overall (P = 0.027). Treatment cessation was reported in 14.5% of non-surgical care subjects and only 4.9% of MMR subjects (n.s.).

CONCLUSION

Treatment with the synthetic MMR implant resulted in significantly greater improvements in knee pain, function, and quality of life at 1 year of follow-up compared to treatment with non-surgical care alone.

LEVEL OF EVIDENCE

I.

Arthroscopic Repair for Parrot Beak Tear of Lateral Meniscus with Reduction Suture and Inside-Out Technique

Parrot beak tear is a white-white meniscal injury that often occurs in isolated injuries. Partial meniscectomy for parrot beak tears is often recommended, owing to the avascular zone; however, partial meniscectomy, especially with the lateral meniscus, has a high failure rate for return to sports, leading to residual meniscus extrusion and lateral compartment osteoarthritis. Thus, we have developed a repair technique to preserve the parrot beak tear of the avascular zone. This is a modification of the inside-out repair with additional reduction sutures. We recommend this procedure as a technique for repairing avascular parrot beak tears of the lateral meniscus.

Effect of Concomitant Meniscal Lesions and Meniscal Surgery in ACL Reconstruction With 5-Year Follow-Up: A Nationwide Prospective Cohort Study From Norway and Sweden of 8408 Patients

Background

Increased knowledge of the factors predicting outcome after anterior cruciate ligament reconstruction (ACLR) is needed.

Purpose

To determine the effect of concomitant meniscal lesions, and the surgical management thereof, on patient-reported outcomes 5 years after ACLR.

Study Design

Prospective cohort study; Level of evidence, 2.

Methods

A total of 15,706 patients who underwent primary unilateral ACLR between 2005 and 2008 were enrolled prospectively and evaluated longitudinally. All patients were part of the Norwegian and Swedish national knee ligament registries. Outcomes at 5-year follow-up were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS). A multivariable linear regression model was used to assess possible effects on prognosis, as measured by KOOS, of a concomitant meniscal lesion and its associated surgical treatment.

Results

At a mean follow-up of 5.1 ± 0.2 years, KOOS data were available from 8408 patients: 4774 (57%) patients with no and 3634 (43%) patients with concomitant meniscal lesions (mean patient age, 33.8 ± 10.7 years). Patients with concomitant meniscal lesions reported equal crude mean scores compared with patients without meniscal lesions in all KOOS subscales 5 years after ACLR. The mean improvement in scores from preoperative to the 5-year follow-up was greater for patients with a concomitant meniscal lesion for the KOOS Pain, Activities of Daily Living (ADL), and Sport and Recreation subscales. In the adjusted regression analyses, using patients without concomitant meniscal lesions as the reference, neither no treatment nor resection or repair of medial meniscal lesions were significantly associated with KOOS scores 5 years after ACLR. Except for the ADL subscale, in which a repaired lateral meniscal lesion was associated with better outcome, no significant associations between any of the lateral meniscal lesion treatment categories and KOOS outcome at 5-year follow-up were identified.

Conclusion

Concomitant meniscal lesions at the time of ACLR conferred no negative effects on patient-reported outcomes 5 years after ACLR. The improvement in selected KOOS subscales from preoperative to the 5-year follow-up was significantly greater for patients with concomitant meniscal lesions than for patients without such lesions.

Meniscal Allograft Transplantation: A Pictorial Review

Meniscal allograft transplantation may be indicated in a subset of patients with high-grade meniscectomy or irreparable meniscal injury and persistent knee pain that is resistant to conservative management. Meniscal allograft transplantation has demonstrated good to excellent results in short-term to midterm follow-up studies and satisfactory outcomes in long-term studies. The goals of this article are to review the indications, preoperative imaging assessment, surgical techniques, and postoperative assessment of uncomplicated and complicated meniscal allograft transplants.

Meniscal Repair Using Fibrin Clots Made From Bone Marrow Blood Wrapped in a Polyglycolic Acid Sheet

Meniscal repair is one of the most common procedures for meniscal tears; however, a previous systematic review showed meniscal repairs have a greater reoperation rate compared with partial meniscectomies. Therefore, an improvement of existing meniscal repair techniques is warranted. Clinical results of polyglycolic acid (PGA) sheets have been reported for rotator cuff repairs. In recent years, we have performed meniscal repairs using wrapped fibrin clots in PGA sheet. We considered the use of wrapped fibrin clots with a PGA sheet to treat meniscus tears. The purpose of this paper is to introduce a step-by-step guide to our new delivery technique using fibrin clots.

Arthroscopic partial meniscectomy: did it ever work?

Arthroscopic partial meniscectomy (APM) is one the most common orthopedic surgical procedures. The most common indication for APM is a degenerative meniscal tear (DMT). High-quality evidence suggests that APM does not provide meaningful benefits in patients with DMTs and may even be harmful in the longer term. This narrative review focuses on a fundamental question: considering the history and large number of these surgeries, has APM ever actually worked in patients with DMT? A truly effective treatment needs a valid disease model that would biologically and plausibly explain the perceived treatment benefits. In the case of DMT, effectiveness requires a credible framework for the pain-generating process, which should be influenced by APM. Basic research, pathoanatomy, and clinical evidence gives no support to these frameworks. Moreover, treatment of DMT with an APM does not align with the traditional practice of medicine since DMT is not a reliable diagnosis for knee pain and no evidence-based indication exists that would influence patient prognosis from APM. A plausible and robust explanation supported by both basic research and clinical evidence is that DMTs are part of an osteoarthritic disease process and do not contribute to the symptoms independently or in isolation and that symptoms are not treatable with APM. This is further supported by the fact that APM as an intervention is paradoxical because the extent of procedure and severity of disease are both inversely associated with outcome. We argue that arthroscopic treatment of DMT is largely based on a logical fallacy: post hoc ergo propter hoc.

Meniscal tears are more common than previously identified, however, less than a quarter of people with a tear undergo arthroscopy

PURPOSE

The management of meniscal tears is a widely researched and evolving field. Previous studies reporting the incidence of meniscal tears are outdated and not representative of current practice. The aim of this study was to report the current incidence of MRI confirmed meniscal tears in patients with a symptomatic knee and the current intervention rate in a large NHS trust.

METHODS

Radiology reports from 13,358 consecutive magnetic resonance imaging scans between 2015 and 2017, performed at a large UK hospital serving a population of 470,000, were assessed to identify patients with meniscal tears. The hospital database was interrogated to explore the subsequent treatment undertaken by the patient. A linear regression model was used to identify if any factors predicted subsequent arthroscopy.

RESULTS

1737 patients with isolated meniscal tears were identified in patients undergoing an MRI for knee pain, suggesting a rate of 222 MRI confirmed tears per 100,000 of the population aged 18 to 55 years old. 47% attended outpatient appointments and 22% underwent arthroscopy. Root tears [odds ratio (95% CI) 2.24 (1.0, 4.49); p = 0.049] and bucket handle tears were significantly associated with subsequent surgery, with no difference between the other types of tears. The presence of chondral changes did not significantly affect the rate of surgery [0.81 (0.60, 1.08); n.s].

CONCLUSION

Meniscal tears were found to be more common than previously described. However, less than half present to secondary care and only 22% undergo arthroscopy. These findings should inform future study design and recruitment strategies. In agreement with previous literature, bucket handle tears and root tears were significant predictors of subsequent surgery.

LEVEL OF EVIDENCE

III.