A Special Tear Pattern of Anterior Horn of the Lateral Meniscus: Macerated Tear

Partial Meniscectomy Yields Comparable Outcomes and Failure Rates to Meniscal Repair for Horizontal Cleavage Tears, With Fewer Complication Rates but Greater Progression of Degenerative Changes

PURPOSE

To compare the clinical outcomes, failure rates, surgical complications, and postoperative radiographic changes following partial meniscectomy versus meniscal repair for horizontal cleavage tears (HCTs).

METHODS

A literature search was performed according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the Scopus, PubMed, and Embase computerized databases. Clinical studies evaluating partial meniscectomy or meniscal repair for HCTs were included. Demographic characteristics, surgical techniques, clinical outcomes, failure rates, complications, and radiographic assessments were recorded.

RESULTS

A total of 18 studies comprising 833 patients with HCTs were included, of which 562 patients (67.5%) were treated with partial meniscectomy and 271 (32.5%) with meniscal repair. Both types of treatments reported improved clinical outcomes, including International Knee Documentation Committee, Lysholm, Knee injury and Osteoarthritis Outcome Score, and Tegner scores. Failure rates were reported to range between 0% and 15% following partial meniscectomy and from 0% to 17.6% following repair; complications were 7.5% after partial meniscectomy and between 3.8% and 21.4% following meniscal repair. Patients undergoing meniscectomy demonstrated progression of degenerative changes on radiographic assessments.

CONCLUSIONS

Repair of HCTs in the appropriately indicated patient can result in similar patient outcomes and failure rates compared to partial meniscectomy. However, especially in patients aged 42 years and younger, a greater complication rate can be expected with repair, while a greater degree of ipsilateral compartment degeneration is seen after partial meniscectomy.

LEVEL OF EVIDENCE

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

Guidelines on the Diagnosis and Treatment of Lateral Meniscal Lesions: A Consensus Statement by the Chinese Society of Sports Medicine

BACKGROUND

The lateral meniscus is a unique structure of the knee joint, and its anatomy, function, pathological process, and treatment are distinct from those of the medial meniscus. To date, no consensus on the management of lateral meniscal lesions has been published, and clinical decision-making is challenging. To facilitate this, consensus and practice guidelines for lateral meniscal lesions were developed and endorsed by the Chinese Society of Sports Medicine.

STUDY DESIGN

Consensus statement.

METHODS

This project followed the Delphi approach to the consensus process, involving steering, rating, and peer review groups. A total of 61 experts in the fields of sports medicine and arthroscopic surgery were invited to participate in the compilation of a consensus statement on lateral meniscal lesions. (The discoid lateral meniscus was addressed by separate consensus.) To begin, the steering group drafted a set of questions and replies regarding lateral meniscal lesions. An online panel discussion was then held to provide initial agreement and comments on the statements, followed by a round of anonymous voting. Results and feedback were sent to the steering group for a second draft. A second round of voting was then held, and each statement was discussed during a combined meeting of the steering and rating groups. Finally, a consensus draft was evaluated by a review group.

RESULTS

Fifty-three questions and answers addressing lateral meniscal lesions were drafted, and 20 statements were excluded because of redundant information during the first round of voting. Ultimately, 33 statements were completed, 9 of which were unanimous.

CONCLUSION

This expert consensus process focused on the anatomy, function, pathological processes, and treatment of lateral meniscal lesions. Accepted recommendations in these areas can assist doctors and therapists in standardizing the management of related pathology. The consensus statement indicates that certain types of lateral meniscal tears that were previously considered irreparable can be repaired. Preservation of the lateral meniscus should be the first-line treatment whenever possible, because the long-term clinical and radiological outcomes are worse after partial meniscectomy.

Radial tears in the anterior third of the lateral meniscus are frequently combined with horizontal tears

INTRODUCTION

Radial tears of the lateral meniscus are often located in the junction of the middle and posterior third or posterior tibial attachment. However, we observed that a few cases of radial tears occurred in the anterior third of the lateral meniscus, and in many cases, they were accompanied by horizontal tears.

HYPOTHESIS

Radial tears are more frequently accompanied by horizontal tears in the anterior third of the lateral meniscus than in other regions.

MATERIAL AND METHODS

From July 2006 to May 2019, patients who underwent arthroscopic surgery for radial tears of the lateral meniscus were included. Patients with radial tears in the anterior third of the lateral meniscus were classified into the anterior group and those with radial tears in the middle and posterior third were classified into the comparison group. Magnetic resonance imaging and arthroscopic findings were reviewed to evaluate whether radial tears were accompanied by other types of tears, especially horizontal tears. The incidence of complex tears between the two groups was compared.

RESULTS

Eighty knees in 79 patients were included. The mean age at the time of surgery was 44.1±16.9 years. The anterior group included 30 knees, and 19 (63.3%) of those also had horizontal tears. In the anterior group, all complex tears were accompanied by horizontal tears, and no other types of accompanying tears were observed. The comparison group included 50 knees, and 16 (32%) of those also had other types of tears. Of the 16 complex tears, 14 had horizontal tears and 2 had longitudinal tears. The incidence of complex tear was significantly higher in the anterior group than in the comparison group (p<.001).

CONCLUSION

Radial tears occurring at the anterior third of the lateral meniscus are frequently accompanied by a horizontal tear. It is important to be aware and predict the occurrence of such characteristic tears and to do proper surgical procedures.

LEVEL OF PROOF

IV; Cross-sectional study.

Clinical and Radiological Outcomes After Isolated Anterior Horn Repair of Medial and Lateral Meniscus at 24 Months' Follow-up, With the Outside-In Technique

Background

The effects of repair of isolated anterior horn meniscus lesions have not been thoroughly described in the literature. We aimed to evaluate outcomes with subjective clinical scores and imaging modalities after repair of isolated anterior horn tears, at 24 months’ follow-up.

Methods

Records of all patients that opted for surgical repair of isolated, anterior horn tears of the medial and lateral meniscus were retrospectively reviewed, between 2016 and 2018. All patients were treated with arthroscopic outside-in technique by the same surgeon. Preoperative and postoperative clinical files were accessed to recover records of preoperative symptomatology, patient-reported scores [International Knee Documentation Committee (IKDC) rating, Lysholm score and Tegner activity level], preoperative and postoperative MRI data and time from injury to surgery.

Results

Mean age of eight patients was 25.25 years (range 18-37 years). Diagnostic preoperative MRI revealed isolated anterior horn tear of the lateral meniscus and medial meniscus in five patients and an isolated anterior horn tear of the medial meniscus in three patients. Mean time from injury to surgical repair was 23.75 days (range 7-43). We considered seven out of eight repairs to be successfully healed. At 24 months’ follow-up: Mean Lysholm score was 92.25 (range 89-95), Tegner activity scale score was 6.5 (range 5-8) and IKDC score was 91.78 (range 87.8-94.4). All scores significantly improved compared to preoperative values (p<0.001).

Conclusions

Outside-in is a reliable technique to repair meniscal anterior horn tears, both medially and laterally, with high healing rates and patient satisfaction in young, active patients.

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.

Magnetic resonance imaging of the meniscal roots

The meniscal roots and supporting structures anchor the menisci to the tibial plateau and resist hoop stress, thereby preventing radial displacement of the menisci and secondary degenerative tibiofemoral compartment changes that may occur if this is compromised. The anatomy of the four meniscal roots and their supporting structures on magnetic resonance imaging (MRI) will be outlined in this review article, as well as the imaging appearances of meniscal root-related pathology, namely meniscal root degeneration and tears, meniscal extrusion and tibial plateau cystic lesions.