Outcomes and failure rates after revision meniscal repair: a systematic review and meta-analysis

A Review of Revision Meniscal Repair: Clinical Considerations and Outcomes

PURPOSE

Meniscus repair is preferred over meniscectomy when possible due to its ability to preserve meniscal tissue and reduce long-term joint degeneration. However, meniscus repair has a risk of failure, resulting in an increasing number of patients presenting with symptoms following a failed repair. Revision meniscus repair remains an option for symptomatic patients, yet guidance on indications, surgical techniques, and expected outcomes is limited. The purpose of this review is to summarize indications, surgical approaches, and outcomes associated with revision meniscus repair.

RECENT FINDINGS

Patient-specific factors such as age, activity level, and modifiable risk factors influence revision repair success. Younger, highly active individuals may be at higher risk of retear due to increased mechanical stress. Tissue quality and vascularity are critical, as degenerative changes and poor perfusion increase failure rates. The gold-standard inside-out technique is often favored for revision repairs due to its superior biomechanical stability. However, all-inside and outside-in techniques remain viable options in specific cases. Biological augmentation, including platelet-rich plasma (PRP) and marrow venting, may enhance healing potential but requires further investigation. Revision meniscus repair demonstrates comparable failure rates and functional outcomes to primary repair, with reported failure rates ranging from 21-33% at mid-term follow-up. Many patients successfully return to high levels of activity following revision repair. Although younger age and high activity levels may predispose to failure, revision meniscus repair remains a viable option for preserving meniscal integrity and optimizing long-term joint health.

Effects of TGF-β3 on meniscus repair using human amniotic epithelial cells

BACKGROUND

Meniscus injury is one of the most common knee diseases, which is managed through conservative and surgical treatments. In recent years, biotherapy has shown great potential to treat various symptoms caused by meniscus injury repair. Human amniotic epithelial cells (hAECs), which are easy to acquire, non-tumorigenic, and high tri-lineage differentiation potential, are a promising cell source for biotherapy and tissue engineering applications. Studies have demonstrated that the Transforming Growth Factor-β3 (TGF-β3) can facilitate chondrocyte differentiation and maturation.

METHODS

Both in vitro test and in vivo test were employed. In the in vitro test, human amniotic epithelial cells (hAECs), human amniotic mesenchymal stem cells (hAMCs), and fibrochondrocytes (FCs) were extracted and identified by flow cytometry and immunohistochemistry (IHC). These cells were treated with TGF-β3 for one week, followed by IHC staining and qPCR to explore TGF-β3-induced fibrocartilage formation in hAECs. In the in vivo tests, a meniscus injury model was established based on rabbits, and the Sham, the control (normal saline), and the hAECs + TGF-β3 groups were used. Additionally, the meniscus was collected and checked through general examination and IHC analysis 90 d after surgery.

RESULTS

Routine transcriptome analysis confirmed that TGF-β3 induced the differentiation of amniotic epithelial cells (hAECs) into fibrochondrocytes through the Wnt signaling pathway. This finding was corroborated using Western blot (WB) and quantitative PCR (QPCR). Among the five experimental groups, the highest expression of target proteins and genes was detected in hAECs + TGF-β3 group, followed by the hAECs + hAMCs + TGF-β3 group, the hAMCs + TGF-β3 group, the hAECs + FCs group, and the FCs group. The observed differences were statistically significant (P < 0.05). In vivo, treatment with hAECs + TGF-β3 facilitated effective repair of damaged menisci.

CONCLUSIONS

hAECs + TGF-β3 can potentially promote the healing of meniscus injuries, laying the foundation for further research to promote its clinical translation.

TRIAL REGISTRATION

Not applicable.

High failure rate in meniscal repair when preceding anterior cruciate ligament reconstruction: An analysis of two-stage surgery for concomitant ACL injury and traumatic meniscus tear

PURPOSE

To investigate the failure rate, predictive factors associated with failure and clinical outcomes after a two-stage surgery; meniscus repair followed by subsequent anterior cruciate ligament (ACL) reconstruction (ACLR).

METHODS

Patients with a concomitant traumatic meniscus tear and ACL injury who underwent a two-stage surgery between January 2015 and January 2021 were identified. The primary outcome was meniscal repair failure, defined as a reoperation (re-repair or resection). A Cox-regression analysis was used in order to analyse factors associated with meniscal repair failure within 3 years after the primary surgery for a meniscal repair. Secondary outcomes were range of motion (ROM), anterior knee laxity and the Knee Injury and Osteoarthritis Outcome Score (KOOS) at 1- and 2-year follow-up. The thresholds of patient acceptable symptom state (PASS), treatment failure (TF) and minimum important change (MIC) were applied to KOOS4 (mean score of the KOOS Pain, Symptoms, Sports/Rec and QoL subscales).

RESULTS

A total of 150 patients were included. The meniscal repair failure rate after 3 years was 36.7%. Failure of meniscal repair was significantly associated with a time interval >1 year between the meniscal repair to the ACLR (hazard ratio [HR] = 2.5; 95% confidence interval [CI] = 1.2-5.5; p < 0.01), medial meniscus repair (HR = 2.3; 95% CI = 1.6-3.4; P < 0.01), and female sex (HR = 1.42; 95% CI = 1.0-1.9; p = 0.01). The age of the patient was not associated with meniscal repair failure. At the 6-month follow-up, most patients (72.5%) showed less than 2 mm of knee laxity; four patients (6.7%) experienced loss of extension and four patients (1.7%) experienced loss of flexion. On the KOOS4, at the 2-year follow-up, PASS was achieved in 53.4%, TF occurred in 1.7%, and MIC was reached in 36.4% of patients.

CONCLUSION

The meniscus repair failure rate after the staged procedure was 36.7% at 3 years. A longer time interval from meniscal repair to ACLR, medial meniscus repair, and female sex were associated with an increased risk of meniscal repair failure. Age was not associated with meniscal repair failure.

LEVEL OF EVIDENCE

Level IV case series retrospective study.

Fibrin clot augmentation of high-risk meniscal repairs may result in clinical healing in up to 90% of cases

OBJECTIVE

While meniscal repair is preferable to meniscectomy, some cases may be at higher risk of failure if repaired. Incorporating fibrin clot (FC) into the repair has been proposed to improve healing rates. The purpose of this study was to determine the failure rates, patient reported outcome measures (PROMs) and complications of FC augmented meniscal repair for cases considered to be at higher risk of failure.

METHODS

A retrospective case series of all patients undergoing FC augmented repair of isolated meniscus tears between January 2016 and September 2021 was undertaken. All cases were thought be at higher risk of failure; they included chronic, radial, complex, horizontal cleavage, and tears not in the red-red zone. Patients were excluded if they had a concomitant anterior cruciate ligament (ACL) reconstruction or if the repair was done through an open incision. The primary outcome was clinical failure defined as further repair or debridement. Secondary outcomes were PROMs and surgical complications. PROMs collected were Lysholm score, Knee injury and Osteoarthritis Outcome Score, Oxford Knee Score and the Tegner score.

RESULTS

Fifty one inside-out meniscal repairs using FC were performed in 50 patients (62% male). The mean age was 34 years (range 14-70). The median time from injury to repair was 122 days (range 4-1565). The medial meniscus was repaired in 63% of cases. Tear types included radial (31%) and complex (39%) and 71% of cases included repair of the white-white zone. 16% of cases were revision meniscal repairs. FC was used in 43% of isolated meniscal repairs during the study period. All patients were followed up to a median of 46 months (range 22-87 months). PROMs at a median of 30 months post-operatively showed statistically significant improvements. Five patients (10%) underwent further surgery for failure after median 21 months. Two patients (4%) reported sensory disturbance around their skin wounds, no other complications were reported. 13% of medial meniscal repairs failed, whereas only 5% of lateral meniscal repairs failed (p ​= ​0.4).

CONCLUSIONS

FC augmented meniscal repair performed for tears considered to be at higher risk of failure may result in acceptably low rates of clinical failure.

LEVEL OF EVIDENCE

Level IV, case series.

The pie-crusting release of the medial collateral ligament in arthroscopic partial meniscectomy is associated with improved clinical outcomes without altering radiological measurements

PURPOSE

The aim of this study was to evaluate how the pie-crusting technique affects clinical and radiological outcomes in patients undergoing arthroscopic partial meniscectomy.

METHODS

A total of 68 patients with Kellgren-Lawrence (K-L) grade 2 who underwent arthroscopic partial meniscectomy between 2015 and 2021 were evaluated and divided into two groups as arthroscopic partial meniscectomy (36 patients) and arthroscopic partial meniscectomy with pie-crusting (32 patients) according to whether the pie-crusting technique was applied or not. All patients were evaluated at a minimum 2-year follow-up in terms of Lysholm score, Tegner activity score, International Knee Documentation Committee (IKDC) score and Visual Analogue Scale (VAS) score. To assess the impact of the pie-crusting technique, radiological measurements were conducted using radiographs taken before and after pie-crusting, as well as postoperative radiographs.

RESULTS

Lysholm, Tegner, IKDC and VAS scores exhibited statistically significant differences after surgery compared to preoperative evaluations in both groups (p < 0.05). Furthermore, these scores were significantly superior in the arthroscopic partial meniscectomy with pie-crusting group compared to the arthroscopic partial meniscectomy group at 24 months postoperatively (p < 0.05). While the radiological measurements in the arthroscopic partial meniscectomy with pie-crusting group showed statistically significant differences before and after pie-crusting (p < 0.05), no significant difference was observed between before pie-crusting and 12 and 24 months postoperatively (n.s.).

CONCLUSION

The current study is the first to demonstrate the true effectiveness of the pie-crusting technique. The application of the pie-crusting technique when necessary results in a statistically significant improvement in clinical scores without affecting radiological measurements for patients undergoing arthroscopic partial meniscectomy compared to not utilising it.

LEVEL OF EVIDENCE

Level III.

Association Between MRI Signal Intensity of the Repaired Lateral Meniscus and Residual Anterolateral Knee Laxity After ACL Reconstruction

Background

Anterolateral knee laxity (ALLx) has been linked to tears of the lateral meniscus (LM) and anterior cruciate ligament (ACL) injury.

Purpose

To investigate the longitudinal relationship between the signal intensity (SI) of the repaired LM on magnetic resonance imaging (MRI) and residual ALLx after ACL reconstruction (ACLR).

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 87 patients who underwent double-bundle ACLR and lateral meniscal repair (mean age, 23.5 years; body mass index, 23.7 kg/m2; 56 women) at a single institution between 2010 and 2019. Proton density-weighted (PDW) and T2-weighted (T2W) MRI was performed at 3, 6, and 12 months postoperatively, and the SI ratio (SIR) was calculated as (SI of the repaired LM)/(SI of the posterior cruciate ligament). At the 12-month follow-up, ALLx was evaluated using the pivot-shift test; an International Knee Documentation Committee grade ≥1 indicated residual ALLx.

Results

Overall, 12 patients (13.8%) exhibited ALLx at 12 months postoperatively. At 3 months postoperatively, the SIR on PDW images (SIR-PDW) was significantly higher in patients with ALLx versus those without ALLx (1.98 ± 0.77 vs 1.49 ± 0.52, respectively; P = .007); there was no difference in the SIR on T2W images between the groups. SIR-PDW at 3 months postoperatively was correlated negatively with patient age (r = -0.308, P = .004). When patients were stratified into a younger (≤22 years; n = 53; ALLx = 7 [13.2%]) and an older (>22 years; n = 34; ALLx = 5 [14.7%]) group, the area under the receiver operating characteristic curves (AUCs) for SIR-PDW in the younger group were statistically significant for predicting the prevalence of ALLx at all follow-up times (AUCs, 0.733-0.788) with optimal cutoff values of 2.00 at 3 months, 1.50 at 6 months, and 1.50 at 12 months. Logistic regression analysis revealed that if younger patients consistently had higher SIR-PDW values than the cutoff values, they were more likely to have residual ALLx (odds ratios, 10.24-23.57).

Conclusion

For younger patients who underwent both ACLR and lateral meniscal repair, higher MRI SI of the repaired LM was associated with a higher prevalence of residual ALLx.

Meniscal Radial Tears: A Classification System Based on Tear Morphology

Appropriate management of radial meniscal tears is complex, with continued efforts focused on optimizing diagnostic methods for identification to help dictate treatment, especially as surgical indications for repair have expanded, coupled with improvements in surgical techniques and instrumentation. Currently, no standardized classification system for radial meniscal tears exists, limiting the ability to accurately characterize injury patterns and guide surgical decision-making.