Arthroscopic repair of meniscal tears that extend into the avascular zone. A review of 198 single and complex tears

Unveiling the mechanical role of radial fibers in meniscal tissue: Toward structural biomimetics

The meniscus tissue is crucial for knee joint biomechanics and is frequently susceptible to injuries resulting in early-onset osteoarthritis. Consequently, the need for meniscal substitutes spurs ongoing development. The meniscus is a composite tissue reinforced with circumferential and radial collagenous fibers; the mechanical role of the latter has yet to be fully unveiled. Here, we investigated the role of radial fibers using a synergistic methodology combining meniscal tissue structure imaging, a computational knee joint model, and the fabrication of simple biomimetic composite laminates. These laminates mimic the basic structural units of the meniscus, utilizing longitudinal and transverse fibers equivalent to the circumferential and radial fibers in meniscal tissue. In the computational model, the absence of radial fibers resulted in stress concentration within the meniscus matrix and up to 800 % greater area at the same stress level. Furthermore, the contact pressure on the tibial cartilage increased drastically, affecting up to 322 % larger areas. Conversely, in models with radial fibers, we observed up to 25 % lower peak contact pressures and width changes of less than 0.1 %. Correspondingly, biomimetic composite laminates containing transverse fibers exhibited minor transverse deformations and smaller Poisson's ratios. They demonstrated structural shielding ability, maintaining their mechanical performance with the reduced amount of fibers in the loading direction, similar to the ability of the torn meniscus to carry and transfer loads to some extent. These results indicate that radial fibers are essential to distribute contact pressure and tensile stresses and prevent excessive deformations, suggesting the importance of incorporating them in novel designs of meniscal substitutes. STATEMENT OF SIGNIFICANCE: The organization of the collagen fibers in the meniscus tissue is crucial to its biomechanical function. Radially oriented fibers are an important structural element of the meniscus and greatly affect its mechanical behavior. However, despite their importance to the meniscus mechanical function, radially oriented fibers receive minor attention in meniscal substitute designs. Here, we used a synergistic methodology that combines imaging of the meniscal tissue structure, a structural computational model of the knee joint, and the fabrication of simplistic biomimetic composite laminates that mimic the basic structural units of the meniscus. Our findings highlight the importance of the radially oriented fibers, their mechanical role in the meniscus tissue, and their importance as a crucial element in engineering novel meniscal substitutes.

Emerging biologic augmentation strategies for meniscal repair: a systematic review

BACKGROUND

Meniscal repair should be the gold standard. However, the meniscus is poorly vascularized and even an excellent meniscus repair may not heal. Therefore, numerous studies and systematic reviews have been carried out on platelet-rich plasma (PRP), mesenchymal stem cells (MSCs) and fibrin clots for meniscal augmentation, but the results remain controversial. This systematic review aimed to identify other emerging strategies for meniscal repair augmentation and to assess whether there are different avenues to explore in this field.

METHODS

A systematic literature review was conducted in August 2022. PubMed, Ovid MEDLINE(R) all, Ovid All EBM Reviews, Ovid Embase and ISI Web of Science databases were searched. In Vivo animal and human studies concerning the biological augmentation of meniscal lesions by factors other than PRP, MSCs or fibrin clots were included. Cartilage-only studies, previous systematic reviews and expert opinions were excluded. All data were analyzed by two independent reviewers.

RESULTS

Of 8965 studies only nineteen studies covering 12 different factors met the inclusion criteria. Eight studies investigated the use of growth factors for meniscal biologic augmentation, such as vascular endothelial growth factor or bone morphogenic protein 7. Five studies reported on cell therapy and six studies focused on other factors such as hyaluronic acid, simvastatin or atelocollagen. Most studies (n = 18) were performed on animal models with gross observation and histological evaluation as outcomes. Polymerase chain reaction and immunohistochemistry were also common. Biomechanical testing was the object of only two studies.

CONCLUSIONS

Although several augmentation strategies have been attempted, none has yielded conclusive results, testifying to a lack of understanding with regard to meniscal healing. More research is needed to better understand the pathways that regulate meniscus repair and how to act positively on them.

LEVEL OF EVIDENCE

Systematic review of case-control and animal laboratory studies.

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.

Repair of radial tears of the lateral meniscus on a stable knee: Results at a minimum follow-up of 2 years

INTRODUCTION

In younger patients, meniscal repair is recommended for isolated lateral meniscus tears that are most often due to acute trauma. But there is little published data on the outcomes of repairing this specific type of lesion. The goal of this study was to evaluate the clinical outcomes, report the failure rate of repairing radial tears of the lateral meniscus in stable knees and determine the risk factors for failure.

MATERIALS AND METHODS

All patients who had a stable knee and underwent arthroscopic repair of a radial lateral meniscus tear between April 2013 and December 2019 were reviewed retrospectively. Failure was defined as revision surgery for recurrence of symptoms (pain, locking) with intraoperative confirmation that the meniscus did not heal. The following data were collected: demographics (age, sex, BMI), time to surgery, clinical outcome scores (Tegner, Lysholm, IKDC), surgical details (repair technique, lesion zone, number of sutures).

RESULTS

Thirty patients were included having a mean age of 20.1years (14-31). The follow-up ranged from 24 to 110months (mean 66.8±25.2). An all-inside repair was done in 6 patients (20%); an outside-in technique was done in 17 patients (57%) and a combination of all-inside and outside-in was done in 7 patients (23%). Four patients (13%) had a recurrence of their symptoms later on, while participating in sports. All the recurrences were at the initial tear site. The time to revision surgery was 16, 19, 24 and 37months in these four patients (mean 24±9). All the other patients were able to resume sports at their pre-injury level. Significant improvement in the IKDC, Lysholm and Tegner functional scores were found between the preoperative and postoperative assessments. No statistically significant risk factors for failure were identified.

DISCUSSION

The functional healing rate after repair of a radial lateral meniscus tear in a stable knee was 86% at a mean follow-up of 5years, with the surgical technique having no impact on the long-term result. Most of the failures occurred within 2years of the repair procedure. We recommend repairing these tears as they have considerable healing potential.

LEVEL OF EVIDENCE

IV; retrospective observational cohort study.

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.

Rates of subsequent surgeries after meniscus repair with and without concurrent anterior cruciate ligament reconstruction

OBJECTIVES

The purpose of this study was to compare the rates of secondary knee surgery for patients undergoing meniscus repair with or without concurrent anterior cruciate ligament reconstruction (ACLr).

METHODS

Utilizing a large national database, patients with meniscal repair with or without concurrent arthroscopic ACLr were identified. The two cohorts were then queried for secondary surgical procedures of the knee within the following 2 years. Frequency, age distribution, rates of secondary surgery, and type of secondary procedures performed were compared.

RESULTS

In total, 1,585 patients were identified: meniscus repair with ACLr was performed for 1,006 (63.5%) and isolated meniscal repair was performed for 579 (36.5%). Minimum of two year follow up was present for 487 (30.7% of the overall study population). Secondary surgery rates were not significantly different between meniscus repair with concurrent ACLr and isolated meniscus repairs with an overall mean follow up of 13 years (1.5-24 years) (10.6% vs. 13.6%, p = 0.126). For the 2 year follow up cohort, secondary surgery rates were not significantly different (19.3% vs. 25.6%, p = 0.1098). There were no differences in survivorship patterns between the two procedures, both in the larger cohort (p = 0.2016), and the cohort with minimum 2-year follow-up (p = 0.0586).

CONCLUSION

The current study assessed secondary surgery rates in patients undergoing meniscus repair with or without concurrent ACLr in a large patient database. Based on this data, no significant difference in rates of secondary knee surgery was identified.

Failure rate, return-to-sports and magnetic resonance imaging after meniscal repair: 119 patients with 7 years mean follow up

BACKGROUND

One of the most important factors to consider in relation to meniscal repair is the high failure rate reported in the existing literature.

AIM

To evaluate failure rates, return to sports (RTS) rate, clinical outcomes and magnetic resonance image (MRI) evaluation after meniscus suture repair for longitudinal tears at a minimum 2-year-follow-up.

METHODS

We conducted a retrospective review of meniscal repairs between January 2004 and December 2018. All patients treated for longitudinal tears associated or not with an anterior cruciate ligament reconstruction (ACL-R) were included. Meniscal ramp lesions, radial and root tears, associated with multiligament injuries, tibial fracture and meniscal allograft transplants were excluded. Surgical details and failure rate, defined as symptomatic patients who underwent a revision surgery, were analyzed. As isolated bucket handle tears (BHTs) were usually associated with higher failure rates, we compared BHTs and not BHTs associated or not with an ACL-R. Since 2014, the inside-out technique using cannulas and suture needles with 2-0 Tycron began to predominate. In addition, the number of stitches per repair was increased. In view of differences in surgical technique, we compared two different cohorts: before and after 2014. We recorded the RTS according to the level achieved and the time to RTS. Lysholm and IKDC scores were recorded. Patients were studied with x-rays and MRI as standard postoperative control.

RESULTS

One hundred and nineteen patients were included with a mean follow up of 7 years (SD: 4.08). Overall failure rate was 20.3% at a mean 20.1 mo. No statistically significant differences were found when comparing failure for medial and lateral meniscal repair (22.7% and 15.3%, P = 0.36), BHTs and not BHTs (26% and 17.6%, P = 0.27), isolated or associated with an ACL-R (22.9% and 18%, P = 0.47), or when comparing only BHTs associated with an ACL-R (23% and 27.7%, P = 0.9) or not. When comparing cohorts before and after 2014, we found a significant decrease in the overall failure rate from 26% to 11% (P < 0.03). Isolated lesions presented a decrease from 28% to 6.6% (P = 0.02), BHTs from 34% to 8% (P = 0.09) and those associated with an ACL-R from 25% to 10% (P = 0.09). Mean RTS time was 6.5 mo in isolated lesions and 8.64 mo when associated with an ACL-R. Overall, 56% of patients returned to the same sport activity level. Mean pre and postoperative Lysholm scores were 64 and 85 (P = 0.02), and IKDC 58 and 70 (P = 0.03). Out of 84 asymptomatic patients evaluated with MRI, 39% were classified as "not healed" and 61% as "healed".

CONCLUSION

Even though the overall failure rate of our series was 20.3%, we found a statistically significant decrease from 26% to 11%, not only for isolated lesions, but also for BHT's and those associated with an ACL-R when comparing our series in two different cohorts, most probably due to improvements in surgical technique.

Design and Finite Element Analysis of Artificial Braided Meniscus Model

Currently, artificial meniscus prostheses are mostly homogenous, low strength, and difficult to mimic the distribution of internal fibers in the native meniscus. To promote the overall mechanical performance of meniscus prostheses, this paper designed a new artificial braided meniscus model and conducted finite element analysis. Firstly, we designed the spatial fiber interweaving structure of meniscus model to mimic the internal fiber distribution of the native meniscus. Secondly, we provided the detailed braiding steps and forming process principles based on the weaving structure. Thirdly, we adopted the models of the fiber-embedded matrix and multi-scale methods separately for finite element analysis to achieve the reliable elastic properties. Meanwhile, we compared the results for two models, which are basically consistent, and verified the accuracy of analysis. Finally, we conducted the comparative simulation analysis of the meniscus model and the pure matrix meniscus model based on the solved elastic constants through Abaqus, which indicated a 60% increase in strength.

Spontaneous Healing of a Posteriorly Displaced Lateral Meniscus Bucket-Handle Tear in a Multiligament Knee Injury: A Case Report

CASE

Bucket-handle meniscus tears (BHMTs) typically involve the medial meniscus and often occur with concomitant rupture of the anterior cruciate ligament. We report an unusual case of a polytrauma patient who sustained a bicruciate multiligament knee injury (MLKI) with a posteriorly displaced lateral BHMT that spontaneously healed after reduction of the fragment. At the 2-year follow-up, the lateral meniscus was clinically stable without pain.

CONCLUSION

A lateral BHMT with a posteriorly displaced fragment produced an atypical magnetic resonance imaging presentation in a bicruciate MLKI. Meniscal repair was aborted because of extravasation and concerns of compartment syndrome, but spontaneous healing occurred after fragment reduction.

Significant risk of arthrolysis after simultaneous anterior cruciate ligament reconstruction and treatment of dislocated bucket-handle meniscal tear

INTRODUCTION

Postoperative stiffness is a feared complication after anterior cruciate ligament (ACL) reconstruction. In case of associated dislocated bucket-handle meniscal tear (BHMT), reduction is urgent, with ligament reconstruction in the same surgical step.

HYPOTHESIS

Treatment of associated dislocated BHMT in ACL reconstruction incurs increased risk of arthrolysis for stiffness in flexion and/or extension.

MATERIAL AND METHODS

A retrospective exposure/non-exposure study included 208 patients undergoing ACL reconstruction between January 2009 and December 2018. Those showing dislocated medial or lateral BHMT at surgery (group A) were compared versus those free of meniscal lesions (group B). The main objective was to assess the risk of surgical revision for arthrolysis within 12 months. Group A included 69 patients: 40 male (58%), 29 female (42%); mean age, 29.0±11.2 years. Group B included 139 patients: 68 male (49%), 71 female (51%); mean age, 30.0±10.4 years. Patients were classified according to age of ACL tear, as acute (<6 weeks), subacute (6 weeks to 6 months), or chronic (>6 months).

RESULTS

Risk of revision surgery for arthrolysis was greater in Group A than in Group B, with 7 (10.1%) and 4 (2.9%) cases respectively (p=0.044), with 12-month arthrolysis-free survival of 89.7% (95% CI, 82.7-97.2) and 97.1% (95% CI, 94.3-99.9) respectively (p=0.023). Stiffness in flexion and extension was more frequent in Group A at 6 weeks and at 6 months (p>0.05). Risk of arthrolysis did not significantly differ according to accident-to-surgery time in the overall series (p=0.421) or specifically in Group A (p=0.887). The BHMT was sutured in 39 cases (56.5%), including 3 failures (7.7%) at 12 months' follow-up. Arthrolysis was required in 6 patients treated by meniscal suture (15.4%) and just 1 patient treated by meniscectomy (3.3%) (p=0.128).

CONCLUSION

The present study confirmed increased risk of surgical revision for arthrolysis after ACL reconstruction in case of dislocated BHMT treated in the same surgical step. Age of ACL tear and type of BHMT treatment (suture or meniscectomy) showed no impact on postoperative stiffness.

LEVEL OF EVIDENCE

IV, retrospective exposure/non-exposure cohort study.

Treatment, Return to Play, and Performance Following Meniscus Surgery

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Prospective Application of Partially Digested Autologous Chondrocyte for Meniscus Tissue Engineering

Background: Meniscus tissue engineering has yet to achieve clinical application because it requires chondrogenic induction and in vitro cell expansion. Contrarily, cartilage engineering from autologous chondrocytes has been successfully applied in one-stage surgery. If the natural chondrogenic potential of meniscus cells can be demonstrated, meniscus tissue engineering would have more value in clinical settings. Materials and Methods: In total, 10 menisci and pieces of cartilage were obtained during total knee replacements. The tissues were collected for cell isolation and expansion. Their chondrogenic properties were examined by immunohistofluorescence and gene expression analyses. Results: In native cartilage, immunofluorescence demonstrated the presence of collagen I, aggrecan, and traces of collagen I, whereas comparable staining was seen in the inner and middle meniscus. The presence of collagen I but the absence of collagen II and aggrecan were observed in the outer meniscus. In passage 2, chondrocytes showed the presence of collagen II and aggrecan, and the absence of vimentin. The vimentin and aggrecan staining were comparable in the inner and middle meniscus cells, whereas the outer cells showed only vimentin staining. In the gene expression analyses, the expressions of collagen II and aggrecan in the native chondrocyte and the inner and middle meniscus were higher than those of the cells from the outer meniscus, but they were not different in collagen I. In the passage 2 culture, chondrocytes had a higher expression of collagen II and aggrecan than the meniscus cells. Cells from the inner and middle areas had higher collagen II and aggrecan expression than those from the outer meniscus. Conclusion: Without chondrogenic induction, inner and middle meniscus cells possess a chondrogenic phenotype. Specifically, native meniscus cells exhibited more robust chondrogenic potential compared with those of the passage 2 monolayer culture.

Isolated meniscus injuries in skeletally immature children and adolescents: state of the art

The prevalence of isolated meniscal injuries in children and adolescents is low; however, we see an increase mainly due to intensified sports-related activities at an early age. A meniscal repair should be attempted whenever possible as children present with increased meniscal healing potential. The diagnosis and management of meniscal tears involve both patient factors and tear characteristics: size, anatomical location and associated injuries. Special attention should be given to the feature of discoid menisci and related tears as they require a specific management plan. This state-of-the-art review highlights the most recent studies on clinical evaluation, surgical techniques, tips and tricks, pitfalls, outcomes, return-to-sports, geographical differences and future perspectives related to meniscal injuries in children and adolescents.

Editorial Commentary: Meniscus Tears Seen at the Time of Anterior Cruciate Ligament Reconstruction Are Overtreated

Meniscus tears seen at the time of anterior cruciate ligament reconstruction are usually asymptomatic, and treatment varies greatly between surgeons, with meniscus repair being used for tears that could be left in situ. Recent outcome studies of most types of lateral meniscus tears show that leaving the tears in situ can give equal or superior results. Meniscus repair being performed for degenerative medial meniscus tears does not give better results than removing the tears. As an alternative to repair, trephination through the meniscus into the peripheral capsule can create many bloody channels to promote healing. Long-term follow-up of meniscus treatment with anterior cruciate ligament reconstruction can help us understand outcomes and prevent us from overtreating tears.

First Clinical Application of Polyurethane Meniscal Scaffolds with Mesenchymal Stem Cells and Assessment of Cartilage Quality with T2 Mapping at 12 Months

BACKGROUND

Complex meniscal lesions often require meniscectomy with favorable results in the short term but a high risk of early osteoarthritis subsequently. Partial meniscectomy treated with meniscal substitutes may delay articular cartilage degeneration.

PURPOSE

To evaluate the status of articular cartilage by T2 mapping after meniscal substitution with polyurethane scaffolds enriched with mesenchymal stem cells (MSC) and comparison with acellular scaffolds at 12 months.

METHODS

Seventeen patients (18-50 years) with past meniscectomies were enrolled in 2 groups: (1) acellular polyurethane scaffold (APS) or (2) polyurethane scaffold enriched with MSC (MPS). Patients in the MPS group received filgrastim to stimulate MSC production, and CD90+ cells were obtained and cultured in the polyurethane scaffold. The scaffolds were implanted arthroscopically into partial meniscus defects. Concomitant injuries (articular cartilage lesions or cartilage lesions) were treated during the same procedure. Changes in the quality of articular cartilage were evaluated with T2 mapping in femur and tibia at 12 months.

RESULTS

In tibial T2 mapping, values for the MPS group increased slightly at 9 months but returned to initial values at 12 months (P > 0.05). In the APS group, a clear decrease from 3 months to 12 months was observed (P > 0.05). This difference tended to be significantly lower in the APS group compared with the MPS group at the final time point (P = 0.18). In the femur, a slight increase in the MPS group (47.8 ± 3.4) compared with the APS group (45.3 ± 4.9) was observed (P > 0.05).

CONCLUSION

Meniscal substitution with polyurethane scaffold maintains normal T2 mapping values in adjacent cartilage at 12 months. The addition of MSC did not show any advantage in the protection of articular cartilage over acellular scaffolds (P > 0.05).

Age-Related Changes in the Microvascular Density of the Human Meniscus

BACKGROUND

The microvascular anatomy of the meniscus of the human knee is regarded as a crucial factor in the injury response. Previous studies have investigated the zone-dependent distribution pattern, but no quantitative data exist on vascular density and its age-related changes.

HYPOTHESIS/PURPOSE

The aim of the present study was to histologically analyze the vascular anatomy of the meniscus as a function of age. It was hypothesized that vascular density would decrease with increasing age.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Human menisci were retrieved from patients who underwent tumor resection or who received total knee replacement because of osteoarthritis. A total of 51 menisci were collected from 28 patients over 9 years (mean age, 25.6 ± 20.4 years; range 3-79 years). Immunohistological staining (alpha-smooth muscle actin) in combination with serial sections and standardized software-based contrast detection were used for the quantitative analysis. Data were analyzed using multiple t tests and the analysis of variance for trends, with a statistical significance level of P < .05.

RESULTS

The overall vascular density in the meniscus was lower in the 61- to 80-year age group than in the age groups of 0 to 10, 11 to 20, and 21 to 30 years (P < .01). A negative linear trend was detected with increasing age (slope, -0.007; P = .016). Within the red-white (RW) zone, a low vessel density was detected for the age groups of 0 to 10 and 11 to 20 years. Beyond these age groups, no vasculature was found in the RW zone. For the white-white (WW) zone, no vessel formations were noted in any age group. Almost 95% of the vessels in the meniscus were located in the capsule.

CONCLUSION

This study reports quantitative histological data for microvascular anatomy as a function of age in a broad cohort of human knee menisci. The overall vascular density decreased with increasing age. No vessel formations were detected in the RW and WW zones after adolescence. Additionally, the capsule is far more densely vascularized than any other part of the meniscus.

CLINICAL RELEVANCE

Vascular density might be an additional factor to consider, along with tear location and patient age, for future treatment options.

The Top 50 Most-Cited Knee Arthroscopy Studies

Purpose

To objectively identify the 50 most influential studies in knee arthroscopy and provide an analysis of their key characteristics.

Methods

The Clarivate Analytics Web of Knowledge database was used to gather data and metrics of knee arthroscopy research. The search list was sorted by the number of citations, and articles were included or excluded based on relevance to knee arthroscopy. The information extracted for each article included author name, publication year, country of origin, journal name, article type, and the level of evidence.

Results

For these 50 studies, the total number of citations was calculated to be 12,168, with an average of 243.4 citations per paper. The most-cited article was cited 1,220 times. The 50 studies included in this analysis were published between 1972 and 2013. All 50 articles were published in English and came from 10 different orthopaedic journals. The United States was responsible for the majority of articles (n = 26); however, many other countries were represented. The most prevalent study designs were case series (n = 20).

Conclusions

The 50 most influential articles in knee arthroscopy were cited a total of 12,168 times. The study designs most commonly used were case series and cohort studies. This article serves as a reference to direct orthopaedic practitioners to the 50 most influential studies in knee arthroscopy. We hope that these 50 studies and the analysis we provide help health care professionals efficiently assess consensus, trends, and needs within the field.

Clinical Relevance

This analysis of the 50 most influential studies in knee arthroscopy will provide medical students, residents, fellows, and attending physicians with a comprehensive inventory and citation analysis of the most impactful academic contributions to one of the most important fields within orthopaedic surgery.

Meniscal Injuries: Mechanism and Classification

Meniscal tears may be managed through conservative physical therapy and nonsteroidal anti-inflammatory medications or operative intervention. Meniscal repair is superior to partial meniscectomy with better functional outcomes and less severe degenerative changes over time. Surgical advances in operative techniques, modern instrumentation and biological enhancements collectively improve healing rates of meniscal repair. However, failed repair is not without consequences and can negative impact patient outcomes. Therefore, it is imperative for surgeons to have a thorough understanding of the vascular zones and biomechanical classifications of meniscal tears in order to best determine the most appropriate treatment.

Degenerative Joint Disease After Meniscectomy

The meniscus has an important role in stabilizing the knee joint and protecting the articular cartilage from shear forces. Meniscus tears are common injuries and can disrupt these protective properties, leading to an increased risk of articular cartilage damage and eventual osteoarthritis. Certain tear patterns are often treated with arthroscopic partial meniscectomy, which can effectively relieve symptoms. However, removal of meniscal tissue can also diminish the ability of the meniscus to dissipate hoop stresses, resulting in altered biomechanics of the knee joint including increased contact pressures. This makes meniscal repair an important treatment consideration whenever possible. Understanding the incidence and mechanism of osteoarthritis development after arthroscopic partial meniscectomy as it relates to different tear morphologies and other treatment alternatives (ie, meniscus repair) is important to appropriately treat meniscus tears.

Meniscal repair: The current state and recent advances in augmentation

Meniscal injuries represent one of the most common orthopedic injuries. The most frequent treatment is partial resection of the meniscus, or meniscectomy, which can affect joint mechanics and health. For this reason, the field has shifted gradually towards suture repair, with the intent of preservation of the tissue. "Save the Meniscus" is now a prolific theme in the field; however, meniscal repair can be challenging and ineffective in many scenarios. The objectives of this review are to present the current state of surgical management of meniscal injuries and to explore current approaches being developed to enhance meniscal repair. Through a systematic literature review, we identified meniscal tear classifications and prevalence, approaches being used to improve meniscal repair, and biological- and material-based systems being developed to promote meniscal healing. We found that biologic augmentation typically aims to improve cellular incorporation to the wound site, vascularization in the inner zones, matrix deposition, and inflammatory relief. Furthermore, materials can be used, both with and without contained biologics, to further support matrix deposition and tear integration, and novel tissue adhesives may provide the mechanical integrity that the meniscus requires. Altogether, evaluation of these approaches in relevant in vitro and in vivo models provides new insights into the mechanisms needed to salvage meniscal tissue, and along with regulatory considerations, may justify translation to the clinic. With the need to restore long-term function to injured menisci, biologists, engineers, and clinicians are developing novel approaches to enhance the future of robust and consistent meniscal reparative techniques.

Excellent medium-term survival of an all-inside tensionable knotted suture device justifies repair of most meniscal tears encountered during reconstructive knee ligament surgery

PURPOSE

All-inside meniscal repair devices have evolved to allow surgeons to undertake complex repairs in a timely and efficient manner. This is advantageous in active patients, where meniscus preservation is critical in preserving joint function and stability. The aim of the study was to evaluate the failure rate of all-inside meniscal repair performed in patients undergoing reconstructive ligament surgery using a particular meniscal repair device.

METHODS

Patients were identified using a single-site prospectively maintained patient registry. Primary outcome was failure, defined as return to surgery with documented failure of repair. Complication rates and functional scores were also recorded. Patients in whom meniscal repair failure was identified were further assessed, to identify any common features.

RESULTS

Over an 8-year period, 323 patients underwent meniscal repair at the time of ligament reconstruction, compared to 244 meniscectomies. Of these, 286 patients underwent repair using an all-inside suture device. One-hundred and twenty-seven repairs were to the medial meniscus only, 124 were lateral, and in 35 patients both menisci were repaired. Follow-up was to a median of 51.5 months. There were 31 (9.7%) failures reported at a median of 22 months post-operatively (IQR 13.5-41.5). Medial repair failures were seen more frequently than lateral (13.6% versus 5.6% OR 2.62 95% CI 1.17-5.88 p = 0.022). Failure of ACL reconstruction was associated with meniscal repair failure (OR 5.83 95% CI 1.55-21.95 p = 0.0039). Multi-ligament reconstruction was undertaken in 70/286 patients receiving meniscal repair and was not associated with failure (OR 1.3 95% CI 0.57-2.98 p = 0.51). Mode number of all-inside sutures used was 3 in both medial and lateral repairs (Range 1-9 lateral; 1-7 medial).

CONCLUSIONS

All-inside repair is a safe and versatile technique which can be used in the majority of meniscal tears encountered during ligament reconstruction with excellent mid-term success. Failure is seen more commonly in medial sided repairs and with failure of ACL reconstruction.

LEVEL OF EVIDENCE

IV.

Meniscal pathology in children and adolescents

The menisci play a key role in knee biomechanics and long-term cartilage protection. Preserving the meniscus is thus a major functional consideration in children and adolescents. In normal menisci, lesions are traumatic in origin. They are often vertical, in the posterior segment, associated with anterior cruciate ligament tear. In abnormal menisci, lesions are much more specific to children, occurring atraumatically, mainly in discoid menisci. Clinical signs of traumatic meniscal lesion are minimal, and associated ligament involvement should be systematically screened for. In contrast, clinical findings are rich and specific in discoid malformative pathology, sometimes showing the typical "clunk" sign highly suggestive of a detachment. The complementary examination of choice is MRI. In children more than in adults, lesions need screening for in apparently normal menisci. This particularly concerns ramp lesions of the medial meniscus. It is important also to be aware of false signs, and notably linear hypersignal of vascular origin in the posterior segment of the medial meniscus. MRI is essential in determining type of tear and guiding surgery in discoid meniscal pathology. Indications for meniscal repair in children are maximal, even in lesions extending into the white zone, and the risk of failure needs to be assumed. All meniscal suture techniques - all-inside, in-out and out-in - need to be acquired. Meniscectomy, even partial, should be exceptional. Treatment of symptomatic discoid meniscus usually involves minimal central meniscoplasty and suture of the discovered lesion. Results of meniscal repair in children are generally very satisfactory, whatever the type or site of lesion. Vertical suture is to be preferred; suture failure is often only partial. In all, optimal treatment of meniscal pathology in children and adolescents requires perfect knowledge of pediatric specificities and above all mastery of repair techniques to restore meniscal tissue as fully as possible so as to conserve future knee function.

Arthroscopic repair of horizontal cleavage meniscus tears provides good clinical outcomes in spite of poor meniscus healing

PURPOSE

The purpose of this study was to evaluate the clinical outcomes and meniscus healing after arthroscopic repair of horizontal-cleavage meniscus tears, compared with vertical-longitudinal meniscus tears.

METHODS

This was a retrospective review of a consecutive series of 52 meniscal repairs for horizontal-cleavage tears (n = 27) or vertical-longitudinal tears (n = 25); the groups were compared with respect to clinical symptoms and meniscal healing. Arthroscopic meniscal repair was performed using the inside-out technique with a marrow-stimulating technique. Clinical symptoms were evaluated using the Lysholm score and Knee injury and osteoarthritis outcome score (KOOS). Meniscus healing was evaluated by MRI.

RESULTS

The mean follow-up periods were 35.4 ± 8.9 months in the horizontal-cleavage tear group and 39.8 ± 8.3 months in the vertical-longitudinal tear group. There were no significant differences in Lysholm score and KOOS, including each subscale, between the horizontal-cleavage tear- and vertical-longitudinal tear-groups at the final follow-up. At the final follow-up, MRI meniscus grades 0 and 1 were significantly more frequent in the vertical-longitudinal tear-group than in the horizontal-cleavage tear-group, while grade 3 was significantly more frequent in the horizontal-cleavage tear group than in the vertical-longitudinal tear group (p < 0.0001).

CONCLUSIONS

Although meniscus healing of horizontal-cleavage tears may be poor, arthroscopic repair should be considered for horizontal-cleavage tears because it does provide good clinical outcomes.

LEVEL OF EVIDENCE

IV.

Microvascular Anatomy and Intrinsic Gene Expression of Menisci From Young Adults

BACKGROUND

Meniscal vascular supply is an important determinant of its healing potential. It has been reported that only the peripheral 30% of the meniscus is vascularized in cadavers aged 53 to 94 years; however, the vascularity in young patients, in whom meniscal repair is more often performed, is unknown.

PURPOSE

The primary objective was to analyze and measure the microvascular anatomy of the meniscus in adult cadaveric specimens <35 years old. The secondary objective was to assess angiogenic potential by quantifying regional gene expression in a meniscal allograft cohort <45 years old.

STUDY DESIGN

Descriptive laboratory study.

METHODS

In part 1 of this study, 13 fresh-frozen cadaveric knees (age range, 22-34 years; mean, 28.5 years) underwent popliteal artery India ink injection and tissue clearing using a Spalteholz technique, followed by microvascular vascular measurement. In part 2, mRNA was isolated from 13 meniscal allografts (age range, 17-43 years; mean, 27.2 years), and expression of angiogenic genes, vascular endothelial growth factor (VEGF), and vascular endothelial growth factor receptor 1 (FLT1) was quantified using real-time polymerase chain reaction.

RESULTS

The maximal depth of vascular penetration into the periphery of the medial and lateral menisci ranged from 0% to 42% and 0% to 48%, respectively. There was variation in the degree of vascular penetration within the medial meniscus, with the posterior horn having a significantly smaller depth of penetration (median, 8.7%) than that of the anterior horn (median, 17.4%; P < .0001) or midbody (median, 17.5%; P = .0003). There were no differences in angiogenesis gene expression (VEGF/FLT1) based on circumferential or radial meniscal locations.

CONCLUSION

The vascular supply of the medial and lateral menisci in specimens from adults <35 years of age extended farther than what was reported in specimens from older individuals; however, median values remained consistent. Gene expression of the angiogenic marker VEGF was low throughout all regions of uninjured menisci from young adults, which is consistent with reports in older specimens.

CLINICAL RELEVANCE

Improved understanding of meniscal vascular supply in young adults is critical to informing clinical treatment decisions.

All-Inside Repair of Bucket-Handle Meniscal Tears: Clinical Outcomes and Prognostic Factors

BACKGROUND

There is no consensus on technique of choice for repair of bucket-handle meniscal tears (BHMTs).

PURPOSE

To determine factors that affect patient outcomes and failure rates in patients undergoing all-inside repairs of BHMTs.

STUDY DESIGN

Systematic review.

METHODS

A systematic review of 3 databases using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed. All English-language literature from 1993 to 2019 describing clinical outcomes for patients undergoing all-inside BHMT repair with ≥12-month follow-up was reviewed by 2 independent reviewers. Patient characteristics (patient sex, age), intraoperative factors (laterality, concomitant procedures, surgical technique, implants utilized), and postoperative outcomes (failure rates) were analyzed. Study quality was evaluated with the Modified Coleman Methodology Score (MCMS).

RESULTS

Fifteen studies (1 level 1, 4 level 3, 10 level 4) with 763 total patients (64% male; average age, 26.4 years [range, 9-58 years]; average follow-up, 39.8 months [range, 12-120 months]) including 396 all-inside BHMT repairs were included. Six devices were used for repair including the Meniscal Repair System, FasT-Fix, Meniscus Arrow, Biofix Arrow, RapidLoc device, and PDS II suture, with failure rates of 13.5%, 22.4%, 27.1%, 42.9%, 45.2%, and 0%, respectively. The overall repair failure rate was 29.3% at an average of 13.0 months (range, 5.0-32.4 months), but 19.0% for devices still in use. The RapidLoc and Biofix Arrow had higher failure rates than other devices (P = .0003). Women (31%) were less likely to experience a failure than were men (69%) (P = .03). Longer follow-up duration resulted in higher failure rates (>30 months, 34.4%; <30 months, 23.4%; P = .016). In 4 studies reporting on both all-inside and inside-out repairs, no significant differences in failure rates were observed. No significant differences in failure rates were found between medial and lateral repairs nor repair with and without concurrent anterior cruciate ligament reconstruction (P > .05 for all). The overall average MCMS was 54.4 ± 12.

CONCLUSION

The overall failure rate after all-inside repair of BHMTs is 29.3% at an average of 13.0 months, with no difference in failure rates between medial and lateral meniscal repairs. The variables shown to negatively affect the failure rates were the RapidLoc and Biofix Arrow, male sex, and longer follow-up duration.

Migration of a Meniscal Repair Implant Mimicking Meniscal Injury

Complications after arthroscopic meniscal suture repair have been reported. Migration of a meniscal repair implant mimicking meniscal injury is rare. A 28-year-old female had undergone Anterior Cruciate Ligament (ACL) reconstruction at another hospital 12 years ago . The remaining instability after ACL reconstruction resulted in medial meniscal damage, wear and narrowing in the posterior third. The H-fix that was used in the meniscal repair became detached, exposing the inside of the knee joint. Meniscal repair is a successful procedure in conjunction with ACL reconstruction. However, when knee instability after ACL reconstruction remains, the choice of meniscal repair implants may lead to potential complications even after long-term clinical follow-up.

Outcomes of arthroscopic repair using the all-inside inter-leaf vertical suture technique for horizontal meniscal tears sustained in sports

The aim of the study was to evaluate the outcomes of arthroscopic repair using the all-inside inter-leaf vertical suture arthroscopic technique for sports-related horizontal meniscal tears.The inter-leaf vertical suture procedure was performed to repair sports-related horizontal tears in the middle and posterior segments of the medial (11 cases) and lateral (2 cases) menisci in 13 patients (mean age: 30 ± 14 years). Pre- and post-operative Barrett criteria, Lysholm scores, and patient ability to resume sports were assessed. Magnetic resonance imaging (MRI) grades and signal intensity changes near the joint capsule were evaluated in the 9 cases among which pre- and post-operative MRI images were available.All Barrett criteria items were negative following surgery; Lysholm scores increased from 70.2 ± 13.1 before surgery to 98.9 ± 2.64 after surgery (P < .01). All patients were able to resume their sport. Preoperative MRI grade of tears was 3 for all patients; postoperative MRI grades were 1 in 3 cases, 2 in 4 cases, and 3 in 2 cases (P < .05). Importantly, MRI signal intensity at the repaired menisci near the joint capsule was reduced in 8 of these 9 cases postoperatively.The inter-leaf vertical suture procedure is associated with good outcomes for horizontal tears in the middle and posterior segments of the medial and lateral menisci. The procedure is useful and convenient.

ARTHROSCOPIC MANAGEMENT OF MENISCAL INJURIES IN ADOLESCENTS: OUTSIDE-IN SUTURING VERSUS MENISCAL DART TECHNIQUE

The aim of this study was to evaluate clinical and subjective outcomes of the meniscal dart technique in patients having undergone arthroscopic meniscal repair by comparing it with the outside-in suturing technique. From January 2006 until June 2017, case records of 37 patients having undergone arthroscopic meniscal repair were retrospectively reviewed. The patients were divided into two groups based on the technique used for meniscal repair, as follows: 18 patients in suture technique group and 19 patients in meniscal dart group. Each patient was analyzed for the following parameters: age, gender, mechanism of injury, side of injury and injured meniscus, injury localization regarding anatomic position, injury type and associated injuries. The patients that underwent meniscal repair were analyzed for type of repair technique, operating results and results of follow-up (Lysholm and International Knee Documentation Committee (IKDC) score). There were no statistically significant differences between the groups according to clinical outcomes except for anatomic injury localization (p=0.035). Median of operation time was 62.5 min in suture technique group and 70 min in meniscal dart group (p=0.184); median of hospital stay was 2 days for both groups (p=0.951); median of Lysholm score was 86.5 and 84.5 (p=0.651); and median of IKDC score was 81.05 and 81.6, respectively (p=0.986). Understanding the harmful impact of meniscectomy, arthroscopic meniscal repair should be attempted whenever possible. Our data support arthroscopic repair of meniscal tears, since both the suture technique and the meniscal dart technique are safe and successful in meniscal repair in children, with good long-term results and without important complications.

Perspective on optical imaging for functional assessment in musculoskeletal extremity trauma surgery

SIGNIFICANCE

Extremity injury represents the leading cause of trauma hospitalizations among adults under the age of 65 years, and long-term impairments are often substantial. Restoring function depends, in large part, on bone and soft tissue healing. Thus, decisions around treatment strategy are based on assessment of the healing potential of injured bone and/or soft tissue. However, at the present, this assessment is based on subjective clinical clues and/or cadaveric studies without any objective measure. Optical imaging is an ideal method to solve several of these issues.

AIM

The aim is to highlight the current challenges in assessing bone and tissue perfusion/viability and the potentially high impact applications for optical imaging in orthopaedic surgery.

APPROACH

The prospective will review the current challenges faced by the orthopaedic surgeon and briefly discuss optical imaging tools that have been published. With this in mind, it will suggest key research areas that could be evolved to help make surgical assessments more objective and quantitative.

RESULTS

Orthopaedic surgical procedures should benefit from incorporation of methods to measure functional blood perfusion or tissue metabolism. The types of measurements though can vary in the depth of tissue sampled, with some being quite superficial and others sensing several millimeters into the tissue. Most of these intrasurgical imaging tools represent an ideal way to improve surgical treatment of orthopaedic injuries due to their inherent point-of-care use and their compatibility with real-time management.

CONCLUSION

While there are several optical measurements to directly measure bone function, the choice of tools can determine also the signal strength and depth of sampling. For orthopaedic surgery, real-time data regarding bone and tissue perfusion should lead to more effective patient-specific management of common orthopaedic conditions, requiring deeper penetrance commonly seen with indocyanine green imaging. This will lower morbidity and result in decreased variability associated with how these conditions are managed.

Patient Outcomes After Horizontal Cleavage Tear Repair: A Systematic Review

PURPOSE

To analyze the clinical outcomes and survivorship of meniscal horizontal cleavage tear (HCT) repairs with hopes of guiding future treatment decisions.

METHODS

Standard systematic review methodology was used. A comprehensive search of PubMed was conducted on June 1, 2019. The inclusion criteria were articles that were published in English, involved human subjects, and reported on at least 1 outcome after repair of HCTs. The exclusion criteria included technique guides and reviews, studies without full text available, and studies with HCT outcomes not separated from other repair groups. Effect heterogeneity was determined using the I² measure. Forest plots were created in addition to a random-effects model to show the results.

RESULTS

The systematic review yielded 19 studies evaluating 289 knees in a total of 273 patients. At most recent follow-up, there was a high probability of return to sport (93.1% [67 of 72]). Overall, 74% of patients (67 of 90) were symptom free at last follow-up, and 80% expressed satisfaction with their overall result (80 of 100). The most frequently reported subjective outcome was the Lysholm score, which improved from a preoperative study range of 48 to 79 (I² = 20.7%, P = .283) to a postoperative study range of 56 to 99 (I² = 49%, P = .081). The next most commonly reported was the International Knee Documentation Committee subjective score, which improved from a preoperative study range of 16 to 49 (I² = 47.7%, P = .125) to a postoperative study range of 72 to 95 (I² = 0%, P = .660). An overall 11.7% reported risk of reoperation was found, with most cases involving revision meniscectomy. Rates of complications beyond fixation failure were overall very low, with infrequent reports of septic arthritis and transitory dysesthesia.

CONCLUSIONS

The short- to intermediate-term results of repair of HCTs are comparable to prior studies. Survivorship is comparable to repairs of other types of meniscal tears with high rates of return to sport and low complication rates.

LEVEL OF EVIDENCE

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

Continuous Meniscal Suture Technique of the Knee

The menisci are fibroelastic structures interposed between the articular surfaces of the femur and tibia. They absorb impact and transmit load. Meniscal injury may compromise function and cause rapid joint degeneration, leading to the development of secondary osteoarthritis. Surgical treatment of meniscal injury is usually performed by arthroscopy, and meniscectomy or meniscal suture may be associated with such treatment. Meniscal suture should be considered when the injury compromises the proper functioning of the meniscus to recover its anatomy and function. Different meniscal suture techniques exist; the most widely used are the inside-out, outside-in, and all-inside techniques. The gold-standard repair technique is the inside-out technique. A drawback of this technique is the need to alternate between intra- and extra-articular structures for every stitch, which makes it even more laborious. We describe the continuous meniscal suture technique, also called "meniscal stitching," for a medial meniscal bucket-handle injury. This technique is performed from the inside out and allows the surgeon to perform multiple stitches with the same thread quickly and effectively. This surgical technique is performed using a single meniscal suture device that was developed by our group, called the "Meniscus 4 A-II" device.

Explant models for meniscus metabolism, injury, repair, and healing

Purpose/Aim: Knee meniscus is a wedge-shaped fibrocartilaginous tissue, playing important roles in maintaining joint stability and function. Injuries to the meniscus, particularly with the avascular inner third zone, hardly heal and frequently progress into structural breakdown, followed by the initiation of osteoarthritis. As the importance of meniscus in joint function and diseases is being recognized, the field of meniscus research is growing. Not only development, biology, and metabolism but also injury, repair, and healing of meniscus are being actively investigated. As meniscus functions as an integrated unit of a knee joint, in vivo models with various species have been the predominant method for studying meniscus pathophysiology and for testing healing/regeneration strategies. However, in vivo models for meniscus studies suffer from low reproducibility and high cost. To complement the limitations of in vivo animal models, several types of meniscus explants have been applied as highly controlled, standardized in vitro models to investigate meniscus metabolism, pathophysiology, and repair or regeneration process. This review summarizes and compares the existing meniscus explant models. We also discuss the advantages and disadvantages of each explant model.Conclusion: Despite few outstanding challenges, meniscus explant models have potential to serve as an effective tool for investigations of meniscus metabolism, injury, repair and healing.

Effect of platelet-rich plasma and platelet-rich fibrin matrix on healing of vertical meniscal tears in a rabbit model

OBJECTIVE

This study aimed to investigate the effect of platelet-rich plasma (PRP) and platelet-rich fibrin matrix (PRFM) on the healing of vertical medial meniscal tears in a rabbit model.

METHODS

The study was conducted on 72 New Zealand mature rabbits aged more than 6 months. Rabbits were randomly assigned to six groups: control (C) group, meniscal repair (MR) group, PRP group, PRFM group, MR+PRP group, and MR+PRFM group, with 12 rabbits in each group. A 5-mm full-thickness vertical tear was created in the avascular zone of the medial meniscus corpus in the right knee of all rabbits. The respective treatment for each group was given to the meniscal tear in each rabbit. Histological evaluation of healing was performed 6 and 12 weeks after surgery.

RESULTS

Defect filling and collagen formation remained low in the C group. However, in all other groups, there was no significant difference in the 6th week. In the 12th week, similar results as those obtained in the 6th week were obtained. In the C group, there was a difference in defect filling and cell type. This difference was that the defect filling and collagen formation remained low in the 12th week. No significant difference was observed between MR, MR + PRP and MR + PRFM groups. The MR group significantly differed from the other groups in the defect-filling rate and cell type; however, the use of PRP and PRFM did not provide an obvious benefit.

CONCLUSION

The contradictory results obtained in previous studies emphasize the need for further research on the use of PRP in meniscal recovery and repair. We believe that if surgery is indicated, repair is absolutely necessary to improve the healing of the tissue in meniscal tears. Studies using human meniscal tissue for meniscal injury and those that evaluate clinical applications of PRP are warranted.

Management of traumatic meniscus tears: the 2019 ESSKA meniscus consensus

PURPOSE

The importance of meniscus integrity in the prevention of early osteoarthritis is well known, and preservation is accepted as the primary goal. The purpose of the ESSKA (European Society for Sports Traumatology, Knee Surgery and Arthroscopy) European consensus on traumatic meniscus tears was to provide recommendations for the treatment of meniscus tears based on both scientific evidence and the clinical experience of knee experts.

METHODS

Three groups of surgeons and scientists elaborated and ratified the so-called formal consensus process to define the recommendations for the management of traumatic meniscus tears. A traumatic meniscus tear was defined as a tear with an acute onset of symptoms caused by a sufficient trauma. The expert groups included a steering group of eight European surgeons and scientists, a rating group of another nineteen European surgeons, and a peer review group. The steering group prepared twenty-seven question and answer sets based on the scientific literature. The quality of the answers received grades of A (a high level of scientific support), B (scientific presumption), C (a low level of scientific support) or D (expert opinion). These question and answer sets were then submitted to and evaluated by the rating group. All answers were scored from 1 (= totally inappropriate) to 9 (= totally appropriate) points. Thereafter, the comments of the members of the rating group were incorporated by the steering group and the consensus was submitted to the rating group a second time. Once a general consensus was reached between the steering and rating groups, the finalized question and answer sets were submitted for final review by the peer review group composed of representatives of the ESSKA-affiliated national societies. Eighteen representatives replied.

RESULTS

The review of the literature revealed a rather low scientific quality of studies examining the treatment of traumatic meniscus tears. Of the 27 questions, only one question received a grade of A (a high level of scientific support), and another received a grade of B (scientific presumption). The remaining questions received grades of C and D. The mean rating of all questions by the rating group was 8.2 (95% confidence interval 8.1-8.4). A general agreement that MRI should be performed on a systematic basis was not achieved. However, MRI was recommended when arthroscopy would be considered to identify concomitant pathologies. In this case, the indication for MRI should be determined by a musculoskeletal specialist. Based on our data, stable left in situ lateral meniscus tears appear to show a better prognosis than medial tears. When repair is required, surgery should be performed as early as possible. Evidence that biological enhancement such as needling or the application of platelet-rich plasma would improve healing was not identified. Preservation of the meniscus should be considered as the first line of treatment because of an inferior clinical and radiological long-term outcome after partial meniscectomy compared to meniscus repair.

DISCUSSION

The consensus was generated to present the best possible recommendations for the treatment of traumatic meniscus tears and provides some groundwork for a clinical decision-making process regarding the treatment of meniscus tears. Preservation of the meniscus should be the first line of treatment when possible, because the clinical and radiological long-term outcomes are worse after partial meniscectomy than after meniscus preservation. The consensus clearly states that numerous meniscus tears that were considered irreparable should be repaired, e.g., older tears, tears in obese patients, long tears, etc. LEVEL OF EVIDENCE: II.

Point-of-Care Procedure for Enhancement of Meniscal Healing in a Goat Model Utilizing Infrapatellar Fat Pad-Derived Stromal Vascular Fraction Cells Seeded in Photocrosslinkable Hydrogel

BACKGROUND

Large radial tears of the meniscus involving the avascular region can compromise meniscal function and result in poor healing and subsequent osteochondral degeneration. Augmentation of surgical repairs with adipose-derived stromal vascular fraction (SVF), which contains mesenchymal stromal cells, may improve meniscal healing and preserve function (ie, chondroprotection).

PURPOSES

(1) To develop a goat model of a radial meniscal tear with resulting osteoarthritis and (2) to explore the efficacy of a 1-step procedure utilizing infrapatellar fat pad-derived SVF cells seeded in a photocrosslinkable hydrogel to enhance meniscal healing and mitigate osteochondral degeneration.

STUDY DESIGN

Controlled laboratory study.

METHODS

A full-thickness radial tear spanning 90% of the medial meniscal width was made at the junction of the anterior and middle bodies of the goat stifle joint. Tears received 1 of 3 interventions (n = 4 per group): untreated, repair, or repair augmented with photocrosslinkable methacrylated gelatin hydrogel containing 2.0 × 10⁶ SVF cells/mL and 2.0 µg/mL of transforming growth factor β3. The contralateral (left) joint served as a healthy control. At 6 months, meniscal healing and joint health were evaluated by magnetic resonance imaging (MRI) and assessed by histological and macroscopic scoring. The Whole-Organ Magnetic Resonance Imaging Score and the presence of a residual tear, as evaluated with T2 MRI sequences, were determined by a single blinded orthopaedic surgeon.

RESULTS

When compared with tears left untreated or repaired with suture alone, augmented repairs demonstrated increased tissue formation in the meniscal tear site, as seen on MRI and macroscopically. Likewise, the neotissue of augmented repairs possessed a histological appearance more similar, although still inferior, to healthy meniscus. Osteochondral degeneration in the medial compartment, as evaluated by the Whole-Organ Magnetic Resonance Imaging Score and Inoue (macroscopic) scale, revealed increased degeneration in the untreated and repair groups, which was mitigated in the augmented repair group. Histological evaluation with a modified Mankin score showed a similar trend. In all measures of osteochondral degeneration, the augmented repair group did not differ significantly from the uninjured control.

CONCLUSION

A radial tear spanning 90% of the medial meniscal width in a goat stifle joint showed poor healing potential and resulted in osteochondral degeneration by 6 months, even if suture repair was performed. Augmentation of the repair with a photocrosslinkable hydrogel containing transforming growth factor β3 and SVF cells, isolated intraoperatively by rapid enzymatic digestion, improved meniscal healing and mitigated osteoarthritic changes.

CLINICAL RELEVANCE

Repair augmentation with an SVF cell-seeded hydrogel may support successful repair of meniscal tears previously considered irreparable.

Factors Predicting Failure Rates and Patient-Reported Outcome Measures After Arthroscopic Meniscal Repair

PURPOSE

To identify factors that affect patient-reported outcome measures (PROMs) and failure rates after arthroscopic meniscal repair.

METHODS

Embase, Embase Classic, and MEDLINE were searched on August 7, 2015, December 23, 2016, and March 11, 2018, for factors associated with PROMs and failure rates after arthroscopic meniscal repair. We excluded studies that (1) were non-English language, (2) did not use human patients, (3) were nonclinical, (4) did not analyze for factors that predicted PROMs or failure rates, and (5) were below Level IV evidence. Studies were graded into higher and lower quality using the Downs and Black scale.

RESULTS

A total of 34 articles met our criteria, and 32 were graded. We identified 16 articles as higher quality. Among higher-quality studies, factors that significantly predicted reduced failure rates were concurrent anterior cruciate ligament reconstruction (ACLR) (n = 6) and reduced tear complexity (n = 4). Factors that did not significantly impact failure rates were side of repair (n = 8), sex (n = 7), time from injury to surgery (n = 7), age (n = 7), rim width (n = 6), and tear length (n = 5). Factors predicting better PROMs were time from injury to surgery of less than 3 months (n = 1), Outerbridge scores below grade 3 or 4 (n = 2), and reduced varus alignment (n = 2). Factors that did not significantly impact PROMs were equipment used (n = 3) and concurrent ACLR (n = 1).

CONCLUSIONS

Factors affecting failure rates and PROMs after arthroscopic meniscal repair were identified. However, more and higher-quality studies supported concurrent ACLR and less complex tears as predictors of lower failure rates. PROMs were negatively affected by a longer time from injury to surgery, higher Outerbridge scores, and greater varus alignment before surgery.

LEVEL OF EVIDENCE

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

Second-Look Arthroscopic Evaluations of Meniscal Repairs Associated With Anterior Cruciate Ligament Reconstruction

PURPOSE

To examine the healing status of meniscal repair performed concomitantly with anterior cruciate ligament (ACL) reconstruction with our current indication and surgical procedure based on second-look arthroscopic results. Additionally, the significance of the demographic and clinical factors that can potentially influence the healing rate was statistically assessed.

METHODS

Between January 2009 and January 2015, second-look was performed for patients who opted to have tibial screw removal and agreed to have concomitant arthroscopy. The healing status of the repaired meniscus was classified into 3 conditions: healed, incompletely healed, and not healed. In addition, clinical outcomes were evaluated at a minimal 1-year follow-up. The effects of patient factors on the meniscal healing rate were statistically assessed.

RESULTS

A total of 217 knees underwent arthroscopic meniscal repair concomitant with ACL reconstruction, while second-look was performed for 105 knees. The average period from index surgery to second-look was 15.0 months. Clinical evaluation was conducted at a mean of 17 months (12-50 months). Based on the second-look arthroscopic findings, 64 menisci, 22 menisci, and 29 menisci were categorized as healed, incompletely healed, and not healed, respectively. When the not healed condition was defined as failed repair, a Tegner activity score of 8 or more, recurrent instability, tears in the red-white to white-white zones, and time from injury to surgery of 4 months or longer were identified as clinical factors significantly correlated with failure (P < .01).

CONCLUSIONS

Meniscal repair in ACL reconstructed knees with expanded indications achieved a healing rate (including incomplete healing) of 75%. Clinical factors such as high sports activity level, recurrent ACL instability, poor vascularity of the repaired site, and long duration from injury to surgery were shown to impair the healing status.

LEVEL OF EVIDENCE

Level Ⅳ, therapeutic study, case series.

Clinical Outcomes of Inside-Out Meniscal Repair According to Anatomic Zone of the Meniscal Tear

Background

There is significant discrepancy in the reported vascularity within the meniscus, and a progressively diminishing blood supply may indicate a differential healing capacity of tears that is dependent on the affected meniscal zone.

Purpose

To examine the outcomes after inside-out meniscal repair in all 3 meniscal vascularity zones.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients were included if they underwent inside-out meniscal repair by a single surgeon between 2010 and 2014 and had a minimum 2-year follow-up. Patients were divided into 3 groups based on the meniscal tear location (red-red, red-white, and white-white zones) as determined during an intraoperative assessment. Patient-reported outcome scores were obtained at final follow-up.

Results

A total of 173 patients (mean age, 33.6 ± 14.3 years) were included, with a mean follow-up of 2.9 ± 0.9 years. All patients demonstrated significant improvements with inside-out meniscal repair from preoperatively to postoperatively, regardless of the meniscal tear location. Patients who underwent meniscal repair in the red-red and red-white zones had significantly increased postoperative Tegner, Lysholm, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores compared with patients who underwent meniscal repair in the white-white zone (P < .05). Patients who underwent acute repair (≤6 weeks) demonstrated significantly higher improvements on the Tegner activity scale (acute: 5.8 ± 2.2; chronic: 4.6 ± 2.2; P = .001) and Lysholm score (acute: 85.6 ± 13.3; chronic: 80.8 ± 13.5; P = .025) compared with patients treated beyond 6 weeks from injury, regardless of the meniscal tear zone. Patients with grade IV femoral condyle chondral lesions at the time of surgery had significantly inferior outcomes compared with patients with grade I through III chondral lesions, regardless of the meniscal tear zone. Three patients (1.7%) subsequently underwent revision inside-out repair, and 3 (1.7%) underwent partial meniscectomy.

Conclusion

Patients who underwent inside-out meniscal repair demonstrated significant improvements on subjective outcome measures at a minimum 2-year follow-up, regardless of the meniscal tear zone. Inside-out meniscal repair is recommended for potentially reparable meniscal tears in all 3 vascular zones; however, improved outcomes can be achieved when performed acutely, in the absence of full-thickness femoral condyle chondral injuries, and in the red-red and red-white zones.

The Safe Distance to the Popliteal Neurovascular Bundle in Pediatric Knee Arthroscopic Surgery: An Age-Based Magnetic Resonance Imaging Anatomic Study

Background:

The close proximity of the popliteal neurovascular bundle to the posterior horn of the lateral meniscus puts it at risk of compromise during lateral meniscal repair. This is particularly important in smaller pediatric patients, who are commonly treated for lateral meniscal abnormalities in isolation (discoid meniscus) or concomitantly with anterior cruciate ligament reconstruction.

Purpose:

To quantify the distance between the posterior horn of the lateral meniscus and the popliteal neurovascular bundle along the path of meniscal repair and to investigate for associations with age, sex, height, weight, body mass index (BMI), and skeletal maturity.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 144 magnetic resonance imaging scans were evaluated in a cohort of patients aged 10 to 18 years without meniscal or ligament abnormalities. Measurements were made along a line from the anterolateral portal between the popliteal neurovascular bundle and the free edge, midpoint, and meniscocapsular junctions of the posterior horn of the lateral meniscus. In addition to descriptive statistics of these distances by age and sex, analyses of variance and linear regression analyses were performed to investigate for associations with age, sex, height, weight, BMI, and skeletal maturity.

Results:

Male participants had a significantly larger mean free edge distance (14.4 ± 2.5 vs 13.1 ± 2.5 mm, respectively; P = .005) and midpoint distance (9.6 ± 2.2 vs 8.9 ± 1.8 mm, respectively; P = .011) than female participants but not a significantly larger meniscocapsular distance (5.2 ± 1.6 vs 4.6 ± 1.4 mm, respectively; P = .096). Linear regression analyses revealed significant associations between these distances and age, height, weight, and BMI (P < .001 for all). There were statistically significant pairwise differences for free edge and midpoint distances to the neurovascular bundle between patients with open and closed physes.

Conclusion:

The distance between the posterior horn of the lateral meniscus and the popliteal vasculature along a trajectory from the standard anterolateral arthroscopic portal increases linearly throughout development between the ages of 10 and 18 years. There were also significant associations between height, weight, BMI, and skeletal maturity and these anatomic distances. Knowing the safe distance to the popliteal vasculature will increase the safety of arthroscopic lateral meniscal repair in children, especially with all-inside devices that require setting the penetration depth for the advancement of a sharp delivery device beyond the posterior capsule.

Efficacy of platelet-rich plasma in arthroscopic repair for discoid lateral meniscus tears

Background

To evaluate the clinical results of arthroscopic repair with or without platelet-rich plasma (PRP) for tears of the discoid lateral meniscus (DLM).

Methods

Twenty-nine patients with DLM tears within a stable knee were arthroscopically treated with meniscal suture repair. Of those, 14 were augmented with platelet-rich plasma (PRP), and 15 were performed without PRP augmentation. Patients were evaluated at baseline (the day before surgery) and then 12 and 24 months after the last injection. Evaluation included the Lysholm score, and Ikeuchi grade, Visual analogue score (VAS) for pain and failure rate. Failure was defined by patients developing symptoms of joint line pain, locking, swelling or requiring repeat arthroscopy.

Results

There was no difference in the failure rate in the PRP group (1 of 14) compared with the non-PRP group (2 of 15) (P = 0.58). Statistically significant improvement in Lysholm score, Ikeuchi grade and VAS for pain was documented at the last follow-up compared with baseline in both PRP and non-PRP group. No significantly difference was found between the PRP group and non-PRP group on Lysholm score, Ikeuchi grade and VAS for pain at the last follow-up. In the univariate analysis of each variable, younger age (P = 0.036) and longer follow-up duration (P = 0.043) were statistically associated with a better function improvement. Whereas in multivariate analysis, only younger age (P = 0.004) was significantly associated with a better function improvement.

Conclusion

With regard to clinical evaluations in arthroscopic repair for DLM tears, PRP group had similar effect in pain relief and functional improvement to non-PRP group at mid-term follow-up. Future larger prospective studies with a longer follow-up are needed to determine whether PRP should be used with DLM repair.

Chondral Injury After Inside-Out Meniscal Suture Repair Using Meniscal Sutures

Chondral injury after arthroscopic meniscal suture repair is rare. We present a case of chondral injury due to the migration of suture after meniscal repair. The aberrant suture that remained temporarily at the medial tibiofemoral joint may have led to the chondral lesion of the femoral medial condyle and the tibial medial plateau at the weight-bearing portion.

Outcomes After the Operative Treatment of Bucket-Handle Meniscal Tears in Children and Adolescents

Background:

Bucket-handle meniscal tears (BHMTs), which we define as vertical longitudinal tears of the meniscus with displacement of the torn inner fragment toward the intercondylar notch region, are a well-recognized tear pattern. Optimizing the management of BHMTs in younger patients is important, as preserving meniscal tissue may limit future joint degeneration.

Purpose/Hypothesis:

The purpose of this study was to review the patient demographics, clinical presentation, operative details, outcomes, and risk factors for a reoperation associated with operatively treated BHMTs in a pediatric population. We hypothesized that the repair of BHMTs in adolescents would yield a higher reoperation rate than meniscectomy in our population.

Study Design:

Case-series; Level of evidence, 4.

Methods:

A departmental database was queried to identify all patients 19 years or younger who presented with a BHMT and underwent surgery between October 2002 and February 2013. Clinical, radiological, and surgical data were retrospectively collected, and risk factors for a reoperation and persistent pain were assessed in all patients with longer than or equal to 6 months of follow-up.

Results:

A total of 280 BHMTs were treated arthroscopically by 1 of 8 sports medicine fellowship–trained surgeons. The mean age at surgery was 15.5 ± 2.5 years (range, 2.1-19.2 years), and most patients were male (177/280; 63%). Most injuries occurred during sports (203/248; 82%) and involved the medial meniscus (157/280; 56%). Concurrent anterior cruciate ligament (ACL) surgery was performed in 103 cases (37%). Meniscal repair was performed in 181 cases (65%) and was more common in younger patients (P = .01) and for the lateral meniscus (P < .001). Among 185 (66%) cases with longer than or equal to 6 months of adequate follow-up data (which included 126 meniscal repairs [68%]), a meniscus-related reoperation occurred in 45 (24%) cases. A reoperation related to the original BHMT injury or surgery was more common after meniscal repair than after meniscectomy (40/126 [32%] vs 5/59 [8%], respectively) (P = .001) and less common with concurrent ACL surgery (P = .07), although this was not statistically significant. Among patients injured during sports and with adequate follow-up, all but 1 patient (176/177; 99%) returned to sports; a slower rate of return was seen in those undergoing meniscal repair (P = .002) and concurrent ACL surgery (P < .001). At final follow-up, 170 of 185 patients (92%) were pain free. For the 15 patients with persistent pain at final follow-up, no identifiable risk factors for persistent pain were identified.

Conclusion:

Most BHMTs in younger patients occurred in males and during sports and affected the medial meniscus. Concurrent ACL surgery was indicated in approximately one-third of cases and was associated with a lower reoperation rate and slower return to sports. Two-thirds of patients underwent meniscal repair, over two-thirds of whom did not require a reoperation during the study period, despite the high activity levels in this age group.

Epidemiological Evaluation of Meniscal Ramp Lesions in 3214 Anterior Cruciate Ligament-Injured Knees From the SANTI Study Group Database: A Risk Factor Analysis and Study of Secondary Meniscectomy Rates Following 769 Ramp Repairs

BACKGROUND

Ramp lesions are characterized by disruption of the peripheral meniscocapsular attachments of the posterior horn of the medial meniscus. Ramp repair performed at the time of anterior cruciate ligament reconstruction (ACLR) has been shown to improve knee biomechanics.

PURPOSE

The primary objectives of this study were to evaluate the incidence of and risk factors for ramp lesions among a large series of patients undergoing ACLR. Secondary objectives were to determine the reoperation rate for failure of ramp repair, defined by subsequent reoperations for partial medial meniscectomy.

STUDY DESIGN

Case-control study; Level of evidence, 3. Case series; Level of evidence, 4.

METHODS

All patients underwent transnotch posteromedial compartment evaluation of the knee during ACLR. Ramp repair was performed if a lesion was detected. Potentially important risk factors were analyzed for their association with ramp lesions. A secondary analysis of all patients who underwent ramp repair and had a minimum follow-up of 2 years was undertaken to determine the secondary partial meniscectomy rate for failed ramp repair.

RESULTS

The overall incidence of ramp lesions in the study population was 23.9% (769 ramp lesions among 3214 patients). Multivariate analysis demonstrated that the presence of ramp lesions was significantly associated with the following risk factors: male sex, patients aged <30 years, revision ACLR, chronic injuries, preoperative side-to-side laxity >6 mm, and concomitant lateral meniscal tears. The secondary meniscectomy rate was 10.8% at a mean follow-up of 45.6 months (range, 24.2-66.2 months). Patients who underwent ACLR + anterolateral ligament reconstruction had a >2-fold reduction in the risk of reoperation for failure of ramp repair as compared with patients who underwent isolated ACLR (hazard ratio, 0.457; 95% CI, 0.226-0.864; P = .021).

CONCLUSION

There is a high incidence of ramp lesions among patients undergoing ACLR. The identification of important risk factors for ramp lesions should help raise an appropriate index of suspicion and prompt posteromedial compartment evaluation. The overall secondary partial meniscectomy rate after ramp repair is 10.8%. Anterolateral ligament reconstruction appears to confer a protective effect on the ramp repair performed at the time of ACLR and results in a significant reduction in secondary meniscectomy rates.

Current concepts in the techniques, indications and outcomes of meniscal repairs

Knee arthroscopy for meniscal tears is one of the most commonly performed orthopaedic procedures. In recent years, there has been an increasing incidence of meniscal repairs, as there are concerns that meniscectomy predisposes patients to early osteoarthritis. Indications for meniscal repair are increasing and can now be performed in older patients who are active, even if the tear is in the avascular zone. Options for meniscal tear management broadly fall into three categories: non-operative management, meniscal repair or meniscectomy. With limited evidence directly comparing each of these options optimal management strategies can be difficult. Decision making requires thorough assessment of patient factors (e.g. age and comorbidities) and tear characteristics (e.g. location and reducibility). The purpose of this paper is, therefore, to review the management options of meniscal tears and summarize the evidence for meniscal tear repair.

Anterolateral Ligament Reconstruction Protects the Repaired Medial Meniscus: A Comparative Study of 383 Anterior Cruciate Ligament Reconstructions From the SANTI Study Group With a Minimum Follow-up of 2 Years

BACKGROUND

The prevalence of osteoarthritis after successful meniscal repair is significantly less than that after failed meniscal repair.

PURPOSE

To determine whether the addition of anterolateral ligament reconstruction (ALLR) confers a protective effect on medial meniscal repair performed at the time of anterior cruciate ligament reconstruction (ACLR).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Retrospective analysis of prospectively collected data was performed to include all patients who had undergone primary ACLR with concomitant posterior horn medial meniscal repair through a posteromedial portal between January 2013 and August 2015. ACLR autograft choice was bone-patellar tendon-bone, hamstring tendons (or quadrupled hamstring tendons), or quadrupled semitendinosus tendon graft with or without ALLR. At the end of the study period, all patients were contacted to determine if they had undergone reoperation. A Kaplan-Meier survival curve was plotted, and a Cox proportional hazards regression model was used to perform multivariate analysis.

RESULTS

A total of 383 patients (mean ± SD age, 27.4 ± 9.2 years) were included with a mean follow-up of 37.4 months (range, 24-54.9 months): 194 patients underwent an isolated ACLR, and 189 underwent a combined ACLR + ALLR. At final follow-up, there was no significant difference between groups in postoperative side-to-side laxity (isolated ACLR group, 0.9 ± 0.9 mm [min to max, -1 to 3]; ACLR + ALLR group, 0.8 ± 1.0 mm [min to max, -2 to 3]; P = .2120) or Lysholm score (isolated ACLR group, 93.0 [95% CI, 91.3-94.7]; ACLR + ALLR group, 93.7 [95% CI, 92.3-95.1]; P = .556). Forty-three patients (11.2%) underwent reoperation for failure of the medial meniscal repair or a new tear. The survival rates of meniscal repair at 36 months were 91.2% (95% CI, 85.4%-94.8) in the ACLR + ALLR group and 83.8% (95% CI, 77.1%-88.7%; P = .033) in the ACLR group. The probability of failure of medial meniscal repair was >2 times lower in patients with ACLR + ALLR as compared with patients with isolated ACLR (hazard ratio, 0.443; 95% CI, 0.218-0.866). No other prognosticators of meniscal repair failure were identified.

CONCLUSION

Combined ACLR and ALLR is associated with a significantly lower rate of failure of medial meniscal repairs when compared with those performed at the time of isolated ACLR.

Comparative Outcomes of All-Inside Versus Inside-Out Repair of Bucket-Handle Meniscal Tears: A Propensity-Matched Analysis

Background:

There are limited data comparing the outcomes of all-inside versus inside-out meniscal repair techniques.

Purpose:

To assess failure rates and clinical outcomes after the surgical repair of bucket-handle meniscal tears utilizing either an all-inside or inside-out technique.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients with bucket-handle meniscal tears undergoing all-inside or inside-out repair at a single institution between 2003 and 2013 were analyzed. A total of 28 mensici repaired utilizing second-generation all-inside suturing devices and 42 menisci repaired using an inside-out technique were eligible for inclusion. Rigorous propensity matching was performed on the basis of age, sex, tear laterality, rim width, and concomitant anterior cruciate ligament reconstruction (ACLR), resulting in a total of 40 patients equally distributed between the 2 repair techniques for comparison. Retear-free survival as well as preoperative and postoperative International Knee Documentation Committee (IKDC) and Tegner scores and physical examination findings were subsequently analyzed.

Results:

Twenty patients who underwent all-inside repair (14 male; mean age, 23.7 ± 6.7 years) were successfully propensity matched to 20 patients who underwent inside-out meniscal repair (15 male; mean age, 22.5 ± 7.6 years), with a mean retear-free follow-up of 4.4 years (range, 2.5-7.4 years). Four (20%) all-inside repairs and 4 (20%) inside-out repairs failed over the course of follow-up (P > .999), with a mean time to failure of 2.7 years (range, 1.3-4.4 years) and 5.0 years (range, 0.8-7.5 years), respectively (P = .25). Increasing patient age trended toward a decreased clinical retear rate, independent of the repair technique (hazard ratio, 0.86; P = .056). There were no significant differences in the Tegner scores, IKDC scores, or range of motion between the groups as a whole or when subcategorizing by age, sex, body mass index, tear complexity, rim width, isolated versus concomitant ACLR, or medial- versus lateral-sided repair. There were no complications in the all-inside group, while there was a 10% rate of minor complications in the inside-out group (P = .49).

Conclusion:

Overall, satisfactory clinical outcomes are achievable at short-term to midterm follow-up with both inside-out and all-inside repair techniques of bucket-handle meniscal tears in rigorously matched patients with similar meniscal tear patterns.

Engineered Healing of Avascular Meniscus Tears by Stem Cell Recruitment

Meniscus injuries are extremely common with approximately one million patients undergoing surgical treatment annually in the U.S. alone. Upon injury, the outer zone of the meniscus can be repaired and expected to functionally heal but tears in the inner avascular region are unlikely to heal. To date, no regenerative therapy has been proven successful for consistently promoting healing in inner-zone meniscus tears. Here, we show that controlled applications of connective tissue growth factor (CTGF) and transforming growth factor beta 3 (TGFβ3) can induce seamless healing of avascular meniscus tears by inducing recruitment and step-wise differentiation of synovial mesenchymal stem/progenitor cells (syMSCs). A short-term release of CTGF, a selected chemotactic and profibrogenic cue, successfully recruited syMSCs into the incision site and formed an integrated fibrous matrix. Sustain-released TGFβ3 then led to a remodeling of the intermediate fibrous matrix into fibrocartilaginous matrix, fully integrating incised meniscal tissues with improved functional properties. Our data may represent a novel clinically relevant strategy to improve healing of avascular meniscus tears by recruiting endogenous stem/progenitor cells.

Are Outcomes After Meniscal Repair Age Dependent? A Systematic Review

PURPOSE

To determine if the failure rate and functional outcome after arthroscopic meniscus suture repair are age dependent.

METHODS

A systematic review was conducted using a computerized search of the electronic databases MEDLINE and ScienceDirect in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Extracted data from each included study were recorded on a standardized form. Studies were included if they (1) were English-language studies in peer-reviewed journals, (2) used a distinct age cut-off to evaluate outcome of meniscal surgery for those above and below the specified cut-off, and (3) used meniscal repairs using suture based technique with inside-out, outside-in, or all-inside techniques. Review papers, case reports, technique papers, non-English language publications, abstracts, and data on meniscal repairs using meniscal screws, arrows, or darts were excluded.

RESULTS

15 of 305 identified articles met the inclusion/exclusion criteria. There were 1,141 menisci treated in 1,063 patients. Seven and 8 studies met the inclusion/exclusion criteria for analysis for the age thresholds of 25 years and 30 years, respectively, demonstrating no difference in failure rates relative to age threshold. Four of 6 studies that met analysis criteria found no difference in failure rates above or below an age threshold of 35 years. No significant difference in failure in patients younger than 40 than patients older than 40 was found for 4 of the 5 studies in that arm of the review.

CONCLUSIONS

Analysis of the composite data in this systematic review reveals that no significant difference exists when evaluating meniscal repair failure rate as a function of age above or below the given age thresholds.

LEVEL OF EVIDENCE

Level IV, systematic review of level III and IV studies.