Arthroscopic repair of degenerative medial meniscus tears in patients aged over 45 years resulted in favorable clinical outcomes and low clinical failure rates at a minimum 2-year follow-up

Redefining Failure: Criteria for Unsuccessful Outcomes in Meniscus Repair

PURPOSE OF REVIEW

Meniscus repair plays a critical role in preserving knee function and delaying degenerative changes after a meniscus tear. Despite advancements in surgical techniques, there remains significant variability in how outcomes are defined and reported. This review examines the evolving interplay between traditional metrics of success such as reoperation rates, radiographic healing, etc., and the more subjective patient reported outcome measures (PROMs).

RECENT FINDINGS

Recent findings highlight the discrepancies between radiographic healing, symptomatic relief, and functional improvement. While reoperation rates remain a widely used failure criterion, they do not account for patients who avoid revision surgery despite persistent symptoms. MRI assessments can detect incomplete healing, but imaging abnormalities do not always correlate with clinical dysfunction. PROMs and return-to-sport (RTS) rates offer valuable insight into functional recovery, yet they vary across studies and may not always reflect anatomical failure. Emerging consensus supports a dual model: anatomical failure, which reflects structural compromise seen on imaging or second-look arthroscopy, and clinical failure, which includes persistent symptoms, limited function, or poor patient-reported outcomes regardless of imaging results. Meniscus repair failure should be assessed using a multidimensional approach, incorporating structural integrity, symptom persistence, functional performance, and patient satisfaction. Standardizing failure definitions will improve data comparability, enhance treatment strategies, and guide patient expectations. Future research should refine composite failure models and integrate meniscus-specific PROMs to optimize long-term outcomes. By redefining failure, clinicians can improve surgical success rates and provide more personalized, evidence-based care.

TAKEAWAY

Not all healed menisci function well, and not all unhealed ones fail. By redefining failure, we can reframe success-and better serve patients.

A Lack of Joint Line Tenderness Is Consistent With a Healed Meniscus, But Positive Clinical Examination Findings and MRI Scans Are Inconsistent in Identifying Failure After Meniscal Repair: A Systematic Review and Subgroup Meta-analysis

BACKGROUND

The number of meniscal repairs being completed each year is increasing; however, the optimal, cost-effective postoperative assessment to determine the success or failure of a meniscal repair is not well known.

PURPOSE/HYPOTHESIS

The purpose of this systematic review was to identify the clinical examination testing that correlates with objective magnetic resonance imaging (MRI) or second-look arthroscopy (SLA) findings to determine an optimal clinical workup for assessing postoperative meniscal repair healing. It was hypothesized that specific clinical tests would correlate with meniscal repairs that did not heal.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

This systematic review included all clinical studies investigating meniscal repairs, meniscal repair outcomes, and meniscal healing with clinical findings, MRI, and/or SLA, published in a peer-reviewed journal and with full English text available. All included studies were evaluated for bias using the Methodological Index for Non-Randomized Studies (MINORS). The clinical tests included those using "Barrett's criteria," with the assessment of effusion, joint line tenderness, locking, McMurray testing, and radiographs. This parameter has also been abbreviated to "modified Barrett's criteria" to include only joint line tenderness, effusion, and McMurray testing.

RESULTS

No significant correlations were found between clinical tests and MRI or SLA. A subgroup meta-analysis between Barrett's and non-Barrett's studies reported no significant subgroup differences (χ12 = 0.24; P = .62). A meta-analysis of diagnostic accuracy using a group of 7 studies that reported on true-positive, true-negative, false-positive, and false-negative data for SLA demonstrated that only a lack of joint line tenderness had a high specificity for a healed meniscal repair, with a log diagnostic odds ratio of 2.62 (95% CI, 0.47-4.76).

CONCLUSION

This study found no significant correlation with any specific clinical test for meniscal repair healing status using postoperative MRI and/or SLA findings. However, it was found that no healing (when compared with complete or incomplete healing) on MRI and joint line tenderness should be considered when assessing the status of postoperative meniscal repair healing. In addition, a subgroup meta-analysis found that a lack of joint line tenderness was highly correlated with a healed meniscal repair.

Conversion to knee arthroplasty is more common after meniscectomy than meniscus repair in patients older than age 40

PURPOSE

To describe rates of conversion to unicompartmental or total knee arthroplasty (KA) in patients over the age of 40 years (at initial surgery) after partial meniscectomy (ME) or meniscal repair (MR).

METHODS

Patients over the age of 40 undergoing isolated ME or MR between 2016 and 2018 were extracted from a single healthcare provider database. Data on patient characteristics, type of initial surgery, number of returns to the operating room, as well as performed procedures, including conversion to KA, were recorded. Comparative group statistics as well as a Kaplan-Meier survival rate analysis were performed.

RESULTS

A total of 3638 patients (47.8% female) were included, with 3520 (96.8%) undergoing ME and 118 (3.2%) MR. Overall, 378 (10.4%) patients returned to the OR at an average of 22.7 ± 17.3 months postoperatively. Conversion to KA was performed more frequently in patients after primary ME (n = 270, 7.7%) compared to those with MR (2.5%, n = 3, odds ratio [OR]: 3.2, p = 0.03). Compared to ME (2.3%, n = 82), two times as many patients undergoing MR returned for subsequent meniscus surgery (MR: 5.9%, n = 7, OR: 2.6, p = 0.02). Time from primary surgery to KA (ME: 22 ± 17 months, MR: 25 ± 15 months, p = 0.96) did not differ between the treatment groups. Survivorship was 95% for ME and 98.2% for MR after 24 months (p = 0.76) and 92.5% and 98.2% after 60 months (p = 0.07), respectively.

CONCLUSION

The overall reoperation rate after meniscal surgery was 10.4% in patients over the age of 40 years. Patients treated with primary ME have over three times higher odds to undergo subsequent KA compared to those treated with MR. However, patients with primary MR have a higher rate of subsequent meniscus surgery compared to those undergoing primary ME. This information is important when considering and treating a patient over the age of 40 and meniscal injury.

LEVEL OF EVIDENCE

Level III study.

Biologic Augmentation of Isolated Meniscal Repair

PURPOSE OF REVIEW

The limited blood supply and intrinsic healing capacity of the meniscus contributes to suboptimal tissue regeneration following injury and surgical repair. Biologic augmentation techniques have been utilized in combination with isolated meniscal repair to improve tissue regeneration. Several innovative strategies such as Platelet-Rich Plasma (PRP), fibrin clots, mesenchymal stem cells (MSCs), bone marrow stimulation, meniscal scaffolds, and meniscal wrapping, are being explored to enhance repair outcomes. This article provides a comprehensive review of recent findings and conclusions regarding biologic augmentation techniques.

RECENT FINDINGS

Studies on PRP reveal mixed outcomes, with some suggesting benefits in reducing failure rates of isolated meniscal repair, while others question its efficacy. Fibrin clots and PRF (Platelet-rich fibrin), although promising, show inconsistent results and lack sufficient evidence for definitive conclusions. MSCs demonstrate potential in preclinical studies, but clinical trials have been limited and inconclusive. Bone marrow stimulation appears effective in certain contexts, but its broader applicability remains uncertain. Meniscal scaffolds, including CMI (Collagen Meniscal Implants) and Actifit (polyurethane scaffolds), show encouraging short- and mid-term outcomes but have not consistently surpassed traditional methods in the long term. Meniscal wrapping is infrequently studied but demonstrates positive short-term results with certain applications. The review reveals a diverse range of outcomes for biologic augmentation in meniscal repair. While certain techniques show promise, particularly in specific scenarios, the overall efficacy of these methods has yet to reach a consensus. The review underscores the necessity for standardized, high-quality research to establish the definitive effectiveness of these biologic augmentation methods.

Higher odds of meniscectomy compared with meniscus repair in a young patient population with increased neighbourhood disadvantage

OBJECTIVES

To investigate the impact of demographic and socioeconomic factors on the management of isolated meniscus tears in young patients and to identify trends in surgical management of meniscus tears based on surgeon volume.

METHODS

Data from a large healthcare system on patients aged 14-44 years who underwent isolated meniscus surgery between 2016 and 2022 were analysed. Patient demographics, socioeconomic factors and surgeon volume were recorded. Patient age was categorised as 14-29 years and 30-44 years old. Area Deprivation Index (ADI), a measure of neighbourhood disadvantage with increased ADI corresponding to more disadvantage, was grouped as <25th, 25-75th and >75th percentile. Multivariate comparisons were made between procedure groups while univariate comparisons were made between surgeon groups.

RESULTS

The study included 1552 patients treated by 84 orthopaedic surgeons. Older age and higher ADI were associated with higher odds of undergoing meniscectomy. Patients of older age and with non-private insurance were more likely to undergo treatment by a lower-volume knee surgeon. Apart from the year 2022, higher-volume knee surgeons performed significantly higher rates of meniscus repair compared with lower-volume knee surgeons. When controlling for surgeon volume, higher ADI remained a significant predictor of undergoing meniscectomy over meniscus repair.

CONCLUSION

Significant associations exist between patient factors and surgical choices for isolated meniscus tears in younger patients. Patients of older age and with increased neighbourhood disadvantage were more likely to undergo meniscectomy versus meniscus repair. While higher-volume knee surgeons favoured meniscus repair, a growing trend of meniscus repair rates was observed among lower-volume knee surgeons.

LEVEL OF EVIDENCE

Retrospective cohort study, level III.

Do MRI Results Represent Functional Outcomes Following Arthroscopic Repair of an Isolated Meniscus Tear in Young Patients?-A Prospective Comparative Cohort Study

BACKGROUND

The use of postoperative MRI to assess the healing status of repaired menisci is a long-standing issue. This study evaluates and compares functional and MRI outcomes following an arthroscopic meniscus repair procedure with the aim of postoperative MRI diagnostic accuracy clarification in young patients.

METHODS

A total of 35 patients under 18 years old who underwent isolated meniscus repair were included. The Pedi-IKDC score, Lysholm score, and Tegner activity index (TAS) were compared between the groups formed according to the Stroller and Crues three-grade classification of postoperative MRI-based evaluations. Grade 3 MRI views were classified as unhealed, grade 2 as partially healed, and grade 1 as fully healed within the repaired meniscus, whereas grade 3 cases were considered unsuccessful due to MRI evaluation.

RESULTS

MRI assessment revealed 4 cases of grade 1 (11.4%), 14 cases of grade 2 (40.8%), and 17 cases of grade 3 (48.0%) lesions. Pedi-IKDC and TAS scores were significantly higher among MRI grade 2 patients than among MRI grade 3 patients (p < 0.05). Weak negative correlations between MRI grades and all functional scales were found (p < 0.05). ROC analysis showed that Pedi-IKDC and TAS scores could correctly classify 77% and 71% of MRI grade 3 patients, respectively. The optimal cut-off values to detect grade 3 patients were 88.74 for the Pedi-IKDC score and 4.5 for the TAS score.

CONCLUSIONS

To conclude, established functional score cut-off values may help identify unhealed meniscus repair patients.

Degenerative Meniscus Tears Treated Nonoperatively With Platelet-Rich Plasma Yield Variable Clinical and Imaging Outcomes: A Systematic Review

Purpose

To perform a systematic review on clinical and radiologic outcomes for meniscus tears treated nonoperatively with platelet-rich plasma (PRP).

Methods

A literature search was performed according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using keywords and Boolean operators in SCOPUS, PubMed, Medline, and the Cochrane Central Register for Controlled Trials in April 2023. Inclusion criteria were limited to Level I to IV human studies reporting on outcomes of meniscus tears treated nonoperatively with PRP.

Results

A total of 6 studies, consisting of 184 patients, were identified. There was 1 Level I study and 5 Level IV studies. Mean patient age was 47.8 ± 7.9 years, with 62% (n = 114/184) being female. The medial meniscus was treated in 95.7% (n = 157/164) of patients. Mean follow-up ranged from 75.9 days to 31.9 months. Meniscus tears were generally described as chronic, degenerative, or intrasubstance. In 4 studies, magnetic resonance imaging revealed variable improvement in meniscus grade with complete healing in 0% to 44% of patients and partial healing in 0% to 40% of patients. Four of 5 studies reported significant statistical improvement in pain from baseline to final follow-up. Studies reporting on clinical outcomes showed significant improvements Lysholm score (2 studies), Knee injury and Osteoarthritis Outcome Score total score (2 studies), and Tegner score (1 study). Successful return to sport occurred in 60% to 100% of patients. Two studies reported that most patients were either very satisfied or satisfied following treatment.

Conclusions

The use of PRP injections for the treatment of meniscus tears led to variable results based on postoperative magnetic resonance evaluation and improvements in clinical outcomes, although the clinical significance remains unclear. The heterogeneity of PRP protocols, short-term follow-up, and lack of comparative studies limit findings.

Level of Evidence

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

All-Inside Arthroscopic Meniscus Repair for Patients Over 40 Years of Age: Is Forty the New Twenty?

INTRODUCTION

Meniscal injuries are a common challenge in orthopedic surgery. For decades, partial or total meniscectomy has been the primary surgical treatment for meniscal tears. In recent years, the increased recognition of menisci's biomechanical importance has progressively shifted the paradigm towards meniscus repair. However, meniscus-sparing surgery remains the treatment of choice for selected lesions in young and active patients, especially for young and active patients. In this study, we evaluated the effectiveness of all-inside sutures in treating meniscus tears in patients over 40.

METHODS

In our retrospective evaluation, we evaluated the clinical and functional outcomes of cases over 40 years of age with post-traumatic acute meniscus tears that received meniscus repairs using the all-inside technique. The pre-operative and post-operative functionality of treated patients were assessed using the knee injury and osteoarthritis outcome score (KOOS) score. Major complications were recorded.

RESULTS

Twenty-three cases met our inclusion criteria. Eight females and fifteen males with a mean age of 44.9 were included in our study. Their mean follow-up was 35.1 months. Before surgery, our patients' mean KOOS score was 55.4 (18-80). At the patients' latest follow-up, the value had risen to 87.4 (63-100). There was no statistical correlation between patients' age and their functional recovery. No surgical failure was recorded at the latest follow-up.

CONCLUSION

The all-inside suture technique can represent a suitable and reliable solution for suturable meniscal tears, even for patients over 40. Preserving the meniscus and restoring patients' functionality allows patients to return to their daily activities and promote their quality of life.

MRI Criteria for Healing at 1 Year After Repair of a Traumatic Meniscal Tear

BACKGROUND

Meniscal repair for a traumatic meniscal tear is increasingly used to preserve the meniscus. Interpreting postoperative magnetic resonance imaging (MRI) scans remains challenging, especially in symptomatic patients. There is a lack of reliable MRI criteria to affirm the healed character of a traumatic meniscal injury repair.

PURPOSE

To identify relevant MRI criteria for meniscal healing after meniscal repair.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We prospectively included all patients with a traumatic meniscal injury who underwent either an isolated meniscal repair or a repair during a concomitant anterior cruciate ligament reconstruction. A standardized preoperative and postoperative clinical evaluation was performed, along with collection of functional scores-Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee, Lysholm Score, and 36-Item Short Form Health Survey. An MRI scan was performed 1 year postoperatively and compared with the preoperative MRI scan. The following MRI aspects were analyzed: variation of morphology and fat-saturated (FS) T2 intensity signal and pre- and postoperative tear diastasis measurement.

RESULTS

Fifty patients (age, mean ± SD, 28.7 ± 8.5 years [range, 16-45 years]) who were 1 year postoperative were included. All patients were considered clinically healed had the same MRI characteristics. A signal change (FS T2) was observed from a high signal intensity fluid to a nonfluid moderate signal intensity. The morphology of the lesion was more complex: from the initial lesion, line ramifications appeared, creating the appearance of tree branches. The tear diastasis decreased (from 2.3 ± 0.5 mm [range, 1.3-3.5] to 1.1 ± 0.28 mm [range, 0.5-1.5]).

CONCLUSION

MRI criteria confirming meniscal healing after traumatic meniscal repair at 1 year were identified: a change in the intrameniscal signal becoming nonfluid and moderate in intensity; a reduction in tear diastasis to <1.5 mm; and a change in the signal morphology of the repaired meniscus.

Outcomes of Meniscal Repair in Patients Aged 40 and Above: A Systematic Review

PURPOSE

Meniscal injuries are increasingly common in older age groups. Age is often cited as a contraindication to undergoing meniscal repair due to concerns regarding failure rates. There has recently, however, been an increasing shift towards repair in older populations. The purpose of this study was to review outcomes of meniscal repair in patients over the age of 40.

METHODS

A systematic search of the following databases was conducted of PubMed, SCOPUS, Web of Science, and Cochrane Library to identify studies reporting failure rates of patients over 40 with meniscal injuries undergoing repair. The definition of meniscus failure was noted for each study evaluated in this systematic review. Further data surrounding clinical and radiological outcomes were recorded and evaluated, when available.

RESULTS

Thirteen studies were included in this review, encompassing a total of 316 meniscal repairs in patients over the age of 40 years. The overall failure rate was found to be 15.5% (49/316) (range 0-33.3%). There was no difference in the failure rate in those over 40 vs. under 40, and the two groups had equivalent functional outcomes.

CONCLUSIONS

Age should not be considered a contra-indication for meniscal repair. Appropriately selected older patients can have acceptably low failure rates with meniscal repair and similar functional outcomes to those under the age of forty. Meniscal repairs in those over 40 achieved better functional outcomes than patients of the same age group who underwent meniscectomy.

Horizontal Cleavage Tear Meniscal Repair Using All-Inside Circumferential Compression Sutures

Horizontal cleavage meniscus tears occur more frequently in older patient populations with degenerative changes within the meniscus. Traditionally, they have been managed with nonsurgical interventions or with partial meniscectomy. As increasing evidence demonstrates the link between partial meniscectomy and progressive osteoarthritis with these types of tears, as well as worse long-term outcomes and reduced cost savings, surgical repair of horizontal cleavage meniscal tears has increased in appropriate patients. This technique article highlights the evaluation, indications, and preferred repair technique for horizontal cleavage tears in appropriately selected patients.

Hidden Unstable Flap Should Be Suspected in Treating Intractable Pain from Medial Meniscus Horizontal Tear

(1) Background: The medial meniscus horizontal tear (MMHT) is known as a lesion that can be treated nonoperatively. However, some patients show persistent pain despite conservative treatments. In arthroscopic surgery for MMHT, surgeons often encounter unexpected unstable flaps, which can explain the intractable pain. This study aimed to determine whether preoperative factors could predict the hidden unstable flaps in MMHT. (2) Materials and Methods: Medical records of 65 patients who underwent arthroscopic partial meniscectomy (APM) for isolated MMHT during 2016–2020 were retrospectively reviewed. APM was indicated when there was no severe chondral degeneration and intractable localized knee pain in the medial compartment did not resolve despite conservative treatments. Unstable flap was confirmed based on arthroscopic images and operation notes. Each of the following preoperative factors were investigated using logistic regression analyses to determine whether they can predict an unstable flap: age, sex, body mass index, lower limb alignment, trauma history, mechanical symptoms, symptom duration, visual analogue scale (VAS), Lysholm score, cartilage wear of the medial compartment, and subchondral bone marrow lesion (BML). (3) Results: Hidden unstable flaps were noted in 45 (69.2%) patients. Based on univariate analyses for each preoperative factor, age, symptom duration, cartilage wear (of the femoral condyle and the tibial plateau), and subchondral BML were included in the multivariate logistic regression analysis. The results showed that symptom duration (p = 0.026, odds ratio = 0.99) and high-grade cartilage wear of the medial femoral condyle (p = 0.017, odds ratio = 0.06) were negatively associated with unstable flaps. A receiver operating characteristic curve was used to calculate the symptom duration at which the prediction of unstable flaps was maximized, and the cutoff point was 14.0 months. (4) Conclusions: More than two thirds of patients suffering intractable pain from MMHT had hidden unstable flaps. However, APM should not be considered when the symptom duration is more than 14 months or high-grade cartilage wear of the medial femoral condyle is noted.