Partial meniscectomy provides the favorable outcomes for symptomatic medial meniscus tear with an intact posterior root

How to Improve Meniscal Repair through Biological Augmentation: A Narrative Review

Since the role of the menisci in knee stability, proprioception, and homeostasis has been well established, significant efforts have been made to repair meniscal tears, resulting in excellent clinical outcomes and a reduction in the progression of knee osteoarthritis (OA). However, varying failure rates have been reported, raising questions regarding the healing potential in cases of complex injuries, poorly vascularized and degenerated areas, and generally in the presence of unfavorable biological characteristics. Therefore, over the last few decades, different strategies have been described to increase the chances of meniscal healing. Biological augmentation of meniscal repair through various techniques represents a safe and effective strategy with proven clinical benefits. This approach could reduce the failure rate and expand the indications for meniscal repair. In the present study, we thoroughly reviewed the available evidence on meniscal repair surgery and summarized the main techniques that can be employed to enhance the biological healing potential of a meniscal lesion. Our aim was to provide an overview of the state of the art on meniscal repair and suggest the best techniques to reduce their failure rate.

Centralization reduces meniscal extrusion, improves joint mechanics and functional outcomes in patients undergoing meniscus surgery: A systematic review and meta-analysis

PURPOSE

To perform a systematic review and meta-analysis of the existing literature on meniscal centralisation procedures, analysing its impact on meniscal extrusion, joint biomechanics and clinical and radiological outcome measures.

METHODS

The Cochrane Controlled Register of Trials, PubMed (MEDLINE) and Embase were used to perform a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Biomechanical studies on healthy animal or human cadaveric knee joints that assessed meniscal extrusion or tibiofemoral contact mechanics (contact area and pressure) following centralization for meniscal pathologies were included. For clinical studies, those that prospectively or retrospectively assessed patient-reported outcome measures (PROMs), postoperative knee motion, complications and radiological extrusion following centralization for meniscal pathologies were included.

RESULTS

Fifteen studies were included in the analysis, comprising eight biomechanical, six clinical and one both. There were 92 knee specimens for biomechanical testing, of which 40 were human cadaveric and 52 porcine models. Biomechanical data revealed centralization to be commonly performed for posterior meniscal root tears and significantly reduced extrusion and contact pressure whilst improving contact area following a tear (p < 0.00001). Centralization restored extrusion to that of the native knee at all flexion angles described (0-90°, p = 0.25) and, compared to the torn state, brought tibiofemoral contact mechanics 3.2-5.0 times closer to the native state. Clinical data showed that 158 patients underwent centralization for extrusion. It improved postoperative Knee Injury and Osteoarthritis Outcome score (KOOS) (p = 0.006) and Lysholm scores (p < 0.00001) at 25.0 months, maintained extrusion reduction at 17.1 months (p < 0.00001) and preserved knee motion.

CONCLUSION

Centralisation for various meniscal injuries associated with extrusion can reduce meniscal extrusion and improve joint biomechanics, along with clinical and radiological outcomes. Existing evidence is still scarce and exhibits a notable amount of methodological heterogeneity.

LEVEL OF EVIDENCE

Systematic review of Level IV evidence.

Long-term clinical and radiological outcomes after arthroscopic partial meniscectomy on stable knees are better for traumatic tears when compared to degenerative lesions: A systematic review

PURPOSE

An arthroscopic partial meniscectomy (APM) for degenerative meniscus lesions and traumatic meniscus tears are two distinct entities and their long-term outcomes are rarely reported. The aim of this review was to compare the long-term (clinical and radiological) results of APM performed on stable knees for traumatic tears (TT) or degenerative lesions (DL).

METHODS

Pubmed, Scopus and Embase databases were searched to identify relevant studies published between 2010 and 2023 using the keywords 'meniscectomy' OR 'meniscectomies' OR 'meniscal resection'. English-language, Levels I-IV evidence studies reporting either radiographic or clinical outcome measures with a minimum of 6 years' follow-up after APM were included. Studies including discoid meniscus, open meniscectomy, unstable knee and combination with other procedures were excluded. To rate the quality of evidence, the methodological index for non-randomized studies was used.

RESULTS

Thirty-two studies were included, with follow-up periods ranging from 6 to 22 years. Eleven studies dealt with TT with a mean age of 31.5 ± 6.6 years and a mean follow-up of 11.6 ± 6.9 years. At the last follow-up, radiographic osteoarthritis (OA) ranged from 36% to 76%, with an average rate of 48 ± 19%; functional scores ranged from 71 to 97, with a mean of 90 ± 4 for the Lysholm score, 86 ± 10 for the International Knee Documentation Committee (IKDC) and 94 ± 16 for the knee injury and osteoarthritis outcome (KOOS). Twenty-one studies dealt with DL with a mean age of 49.9 ± 7.2 years and a mean follow-up of 14.9 ± 6.3 years. At the last follow-up, radiographic OA ranged from 23% to 97%, with an average rate of 77 ± 28%; functional scores ranged from 40 to 87, with a mean of 79 ± 10 for the Lysholm score and 71 ± 16 for the IKDC.

CONCLUSION

Ten-year clinical outcomes of APM are better for TTs when compared to DLs. Rates of OA are difficult to compare but lower for TTs.

LEVEL OF EVIDENCE

Level IV.

Ipsilateral chondral lesions worsen the long-term prognosis following arthroscopic partial medial meniscectomy

PURPOSE

The effect of knee cartilage defects that are detected during partial meniscectomy remains controversial in terms of the long-term prognosis on knee function. This study aimed to investigate the effect of concurrent medial compartment focal cartilage lesions on the long-term prognosis of knee function in patients who underwent arthroscopic partial medial meniscectomy for traumatic medial meniscal tears.

METHODS

This retrospective study analyzed 46 patients who underwent arthroscopic partial medial meniscectomy between 1991 and 2008 by a single surgeon. Twenty-one patients who underwent arthroscopic partial medial meniscectomy due to traumatic meniscal tear had focal chondral lesions only at the medial compartment, and these patients were assigned to group A. Twenty-five patients who had no cartilage lesions in any compartments were assigned to group B. The age, sex, body mass index (BMI), follow-up time, age at the time of surgery, clinical and radiological scores, and perioperative arthroscopy findings were analyzed.

RESULTS

The mean follow-up time was 20 ± 3.7 years. No significant difference was found in the demographic data, and the average age of the patients at the time of operation was 35 ± 9.5 years. Both groups had improved Lysholm score at the last follow-up. Although no difference was found between the groups during the preoperative period, group B had a higher Lysholm score at the last follow-up than group A. The mean International Knee Documentation Committee (IKDC) and Knee injury and Osteoarthritis Outcome Score (KOOS) scores at the last follow-up were significantly higher in group B. The mean Kellgren-Lawrence grades in the operated knees of group A were higher than those of group B. In group A, a negative correlation was found between the BMI and postoperative Lysholm (r =  - 0.461, p = 0.03) IKDC (r =  - 0.433, p = 0.05) and KOOS (r =  - 0.565, p = 0.008) scores. In group B, no correlation was found between BMI and any score.

CONCLUSION

Among patients who underwent arthroscopic partial medial meniscectomy with an average follow-up of 20 years, those with concurrent focal cartilage defect in the medial compartment had clinically and radiologically worse outcomes than patients without any cartilage defect. Therefore, orthopedic surgeons should be meticulous before performing any arthroscopic partial medial meniscectomy in case of concurrent cartilage lesion.

LEVEL OF EVIDENCE

Level III.

Medial meniscus posterior root tears and partial meniscectomy significantly increase stress in the knee joint during dynamic gait

PURPOSE

As a simple and invasive treatment, arthroscopic medial meniscal posterior horn resections (MMPHRs) can relieve the obstructive symptoms of medial meniscus posterior root tears (MMPRTs) but with the risk of aggravating biomechanical changes of the joint. The aim of this study was to analyze dynamic simulation of the knee joint after medial meniscus posterior root tear and posterior horn resection.

METHODS

This study established static and dynamic models of MMPRTs and MMPHRs on the basis of the intact medial meniscus model (IMM). In the finite element analysis, the three models were subjected to 1000 N axial static load and the human walking gait load defined by the ISO14243-1 standard to evaluate the influence of MMPRTs and MMPHRs on knee joint mechanics during static standing and dynamic walking.

RESULTS

In the static state, the load ratio of the medial and lateral compartments remained nearly constant (2:1), while in the dynamic state, the load ratio varied with the gait cycle. After MMPHRs, at 30% of the gait cycle, compared with the MMPRTs condition, the maximum von Mises stress of the lateral meniscus (LM) and the lateral tibial cartilage (LTC) were increased by 166.0% and 50.0%, respectively, while they changed by less than 5% during static analysis. The maximum von Mises stress of the medial meniscus (MM) decreased by 55.7%, and that of the medial femoral cartilage (MFC) increased by 53.5%.

CONCLUSION

After MMPHRs, compared with MMPRTs, there was no significant stress increase in articular cartilage in static analysis, but there was a stress increase and concentration in both medial and lateral compartments in dynamic analysis, which may aggravate joint degeneration. Therefore, in clinical treatments, restoring the natural structure of MMPRTs is first recommended, especially for physically active patients.

Association of Postoperative Lateral Meniscal Extrusion With Cartilage Degeneration on Magnetic Resonance Imaging After Discoid Lateral Meniscus Reshaping Surgery

Background:

Although arthroscopic reshaping surgery for a discoid lateral meniscus (DLM) has good clinical results, it cannot completely prevent degeneration. The degree of DLM extrusion associated with degenerative changes is unclear.

Purpose/Hypothesis:

To measure meniscal extrusion preoperatively and postoperatively in patients who underwent DLM-reshaping surgery and examine factors associated with knee articular cartilage degeneration. It was hypothesized that meniscal extrusion existed preoperatively, progressed postoperatively, and was related to knee joint degeneration.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

We retrospectively reviewed the medical records of patients who underwent DLM-reshaping surgery and attended ≥2 years of follow-up. Magnetic resonance imaging (MRI) was performed preoperatively and at 24 months postoperatively, and residual midbody meniscal extrusion was measured. Cartilage degeneration was detected when the Whole-Organ Magnetic Resonance Imaging Score (WORMS) of the lateral compartment was grade ≥3 at 2 years postoperatively. Factors associated with MRI cartilage degeneration were evaluated.

Results:

Included in this study were 48 knees in 39 patients; the mean patient age at the time of surgery was 12.0 years. The mean midbody meniscal extrusion significantly increased from 0.8 mm preoperatively to 1.6 mm at 24 months postoperatively ( P < .001). According to the WORMS cartilage score, 16 patients were categorized as having MRI cartilage degeneration. Multivariate logistic analysis showed that an inferior preoperative Lysholm score (odds ratio, 0.89; P = .024) and postoperative extrusion (odds ratio, 6.18; P = .010) significantly increased the risk of cartilage degeneration. The receiver operating characteristic curve showed that a residual meniscal extrusion of 2.0 mm was the cutoff value indicating cartilage degeneration (sensitivity, 87.5%; specificity, 78.1%).

Conclusion:

DLM extrusion significantly increased from 0.8 mm preoperatively to 1.6 mm at 2 years postoperatively. Postoperative extrusion and a lower preoperative Lysholm score were factors related to MRI cartilage degeneration postoperatively. A postoperative extrusion of 2.0 mm was the cutoff value for MRI cartilage degeneration.

Morphological Analysis of Normal Meniscus on Magnetic Resonance Imaging (MRI)-Based Three-Dimensional Reconstruction Models in Healthy Chinese Adults

Background

The purpose of this cross-sectional observational study was to determine the morphological meniscus characteristics in a normal Chinese population and assess possible relationships between demographic data and meniscal morphological parameters.

Material/Methods

We examined 116 menisci (58 lateral and 58 medial) from 29 healthy Chinese volunteers (10 men, 19 women, mean age 26 years [range, 20–33 years]) with MRI and three-dimensional reconstruction using Mimics software. The width, thickness, anteroposterior distance (APD), lateral-medial distance (LMD), and covering angle (CA) were measured on reconstructed models. Univariate analysis was used to evaluate the differences of morphological parameters between the medial and lateral menisci, between sides, and between males and females. Pearson correlation analysis was used to evaluate the correlation between meniscal morphological parameters and body height, weight, and body mass index (BMI).

Results

Univariate analysis demonstrated that the width, thickness, APD, LMD, and CA were significantly different between lateral and medial menisci. The LMD and APD of menisci in men were significantly larger than in women. There was no significant difference in meniscal thickness and CA between males and females. The lateral meniscus dimensions were slightly larger in the right knee. According to Pearson correlation analysis, the APDs of both lateral and medial menisci were strongly correlated with height and weight (lateral: r=0.596, r=0.500; medial: r=0.684, r=0.680).

Conclusions

The morphologies of medial and lateral menisci were different and were not significantly correlation with each other. The meniscal width and diameter were correlated with demographic data, but the thickness and CA did not significantly differ by sex, height, or BMI.

Traumatic avulsion of the anterior medial meniscus root combined with PCL injury: a case report

Background

Avulsion of the anterior medial meniscus root (AMMR) has a low incidence rate, especially when it is combined with posterior cruciate ligament (PCL) injury, which hasn’t been reported in any literature to date. The aim of this study was to share our experience in the diagnosis and treatment of a patient with traumatic avulsion of AMMR combined with PCL injury.

Case presentation

This article reports a 26-year-old male patient diagnosed with traumatic avulsion of the AMMR with PCL injury. After arthroscopic surgery, he achieved remission of symptoms and recovery of functions.

Conclusions

Anterior meniscus root injuries are relatively rare. Its diagnosis can be made preliminarily based on clinical manifestations, physical examinations, and magnetic resonance imaging (MRI), and then confirmed by arthroscopic exploration. Arthroscopic suture anchor fixation of the injured anterior meniscus horn shows a good therapeutic effect.

Partial Medial Meniscectomy Using Needle Arthroscopy and a Standardized Local Anesthetic Protocol

Needle arthroscopic procedures of the knee offer potential advantages over standard arthroscopic procedures. The small size of the instruments allows for surgery without the use of a scalpel or suture, potentially decreased recovery times, and potentially reduced complication rates compared with traditional arthroscopy. In some patients, the procedure can be performed without the use of either general anesthesia or sedation. The purpose of this article is to provide a standardized technique guide for needle arthroscopic partial medial meniscectomy under local anesthesia.

Reduction of in situ force through the meniscus with phased inner resection of medial meniscus: an experimental study in a porcine model

PURPOSE

Partial meniscectomy can cause osteoarthritic changes in knees, as inner portion as well as peripheral portion of meniscus is important. The hypothesis of this study was that the amount of the inner resection of medial meniscus affected the in situ forces through the meniscus and the tibial varus and external rotation under axial load.

METHODS

Fourteen intact porcine knees were investigated with a six-degree of freedom robotic system and force/moment, and the three-dimensional path of intact knees were recorded by universal force sensor when an axial load of 300-N was applied at four different flexion angles (30°, 60°, 90°, and 120°). The same examination was performed on three phased inner resections (30%, 60%, and 90% width) of the medial meniscus. Finally, all paths were reproduced after total medial meniscectomy, and in situ forces of the medial meniscus were calculated based on the superposition principle. Changes in tibiofemoral varus/valgus and internal/external rotation alignment during an axial load were also calculated.

RESULTS

In situ forces of the medial meniscus decreased according to the amount of meniscal resection at all flexion angles. The reduction was significant in knees with inner resections of > 60% width at all flexion angles and even of 30% width at a flexion angle of 120° (p < .05). Incremental changes in the tibiofemoral varus alignment increased depending on the inner resection width at all flexion angles (p < .05).

CONCLUSION

The amount of inner resection of the medial meniscus was related to reduction of its in situ forces and increment of the tibial varus rotation under axial load.

Editorial Commentary: Meniscal Repair-Why Bother?

Whether to repair or resect meniscal tears remains a matter of controversy. In theory, partial meniscectomy increases contact pressure, which may result in progressive and early cartilage degeneration and early osteoarthritis. Meniscal preservation is the preferred treatment option, but only a small percentage of meniscal tears are suitable for repair. Two recent registry studies challenge this approach and suggest that partial meniscectomy has similar clinical outcomes in the short term. Whether these findings can be maintained in the long term remains to be seen.