Meniscus Repair - Clinical Tree

Introduction

The paradigm change in the operative treatment of meniscal injuries from meniscectomy to repair when possible has significantly transformed the management of these injuries. A better understanding of the important roles of the meniscus and the devastating consequences of complete or extensive partial meniscectomy, as well as the introduction of new techniques and sophisticated devices for meniscus repair, ^, ^, ^, may all play a role in this ongoing process. In addition, the literature shows that patients have better long-term patient-reported outcomes and better activity levels after meniscal repairs than after a meniscectomy. ^, ^,

The type of meniscal tear, size of tear, location of tear, vascularity of the area, mechanism of injury, and chronicity of injury are all important characteristics that influence the reparability of meniscal tears. In addition, the patient’s age, function, goals, and expectations are also important factors to consider. ^,

Meniscal repair can be performed with either an arthroscopic, open, or combined technique. The arthroscopic technique can be divided in to four categories: (1) the inside-out technique; (2) the outside-in technique; (3) the all-inside technique; and (4) a combined technique.

In this chapter we review the complications of meniscal repair in the setting of preoperative, intraoperative, and postoperative management.

Preoperative Management

Incorrect or Partial Diagnosis

Knee symptoms can be difficult to diagnose properly, especially in the presence of several findings in the patient’s history, clinical exam, and imaging. Meniscus pathology will not always be the patient’s pain source, and operative treatment with meniscus repair in these instances will lead to a dissatisfied patient and worse outcomes. ^,

Prevention: The surgeon must correlate the patient’s complaints and symptoms with the patient’s history, physical examination findings, and imaging findings to rule out other possible etiologies for the patient’s symptoms. In terms of physical examination findings, joint line tenderness, a positive McMurray test, and mechanical catching or locking can be highly suggestive of a meniscal source of knee pain and dysfunction. Examination under anesthesia and the diagnostic part of arthroscopy are additional tools by which a surgeon can identify additional pathologies that can contribute to the patient’s condition and symptoms.
Recognition: No improvement in symptoms after the surgical intervention.
Management: Thorough evaluation for additional possible sources of knee symptoms.

Poor Patient Selection

Patient selection is a crucial element of successful outcomes after meniscal repairs. Preserving and repairing the meniscus should be reserved for tears with adequate healing potential. For example, a combination of a complex degenerative tear located in the avascular inner third of the meniscus in an older patient who has not had an acute injury has very limited healing potential, and will probably fail if repaired. Furthermore, a patient’s expected clinical outcome, daily function, and expected adherence to a specific postoperative rehabilitation protocol should also be considered when tailoring the optimal treatment for the patient. ^, ^, ^,

Prevention: Appropriate evaluation of patients and assessment of both their characteristics and the characteristics of the meniscal tear. Meniscal tear characteristics should be evaluated by all tools available to the surgeon: history, physical examination, imaging, and the diagnostic part of the arthroscopy when an arthroscopy is planned.

Specific Considerations

Patient age. There is conflicting literature as to the effect of patient age on surgical outcomes after meniscal repair. On the one hand, meniscal tissue from patients over 40 years of age has less cellularity and decreased healing response than tissue from younger patients, suggesting a lower failure rate in young patients. However, on the other hand, it has been shown that the healing of repaired meniscal tears is poor in young patients (children and adolescents), despite better intrinsic healing potential. Furthermore, a large database study showed that older age is associated with decreased risk of subsequent meniscectomies after meniscal repair. One possible reason is the higher demands in daily living, occupation, and sports in the young population. Published evidence suggests ^, suggests that there is no significant difference in meniscal repair failures as a function of age. Therefore, age alone should not be considered as an absolute contraindication to meniscal repair, and should be taken into consideration with other factors.

Meniscal tear chronicity. Chronicity of symptoms could indicate a degenerative meniscal tear and osteoarthritic joint changes. A comprehensive arthroscopic evaluation of the meniscal tear tissue and chondral status could also indicate a degenerative etiology. It has been shown that the healing potential in the setting of chronic degeneration is low, ^, and repair is not recommended in this scenario.

Meniscal tear patterns. Favorable tear patterns with better healing potential are vertical longitudinal tears, ^, whereas less favorable patterns include complete radial, oblique, horizontal cleavage, and complex patterns. ^, ^, ^, Nevertheless, the usage of new techniques and instrumentation shows encouraging results in more challenging meniscal tears patterns, including complete radial tears ^, and meniscal root tears or avulsions, where repair is believed to aid in delayed progression of knee osteoarthritis. ^, Lastly, medial meniscocapsular tears (“Ramp” lesions), which have regained attention in recent years have shown good healing potential and clinical outcomes after repair ( Fig. 2.1 and 2.2 ).

Meniscal injury not indicated for repair. Small or partial-thickness tears can heal without intervention. In addition, stable peripheral tears can be treated with abrasion and trephination only (e.g., lateral meniscus tears near the popliteal hiatus). ^, ^, Overtreatment with unnecessary repair or over repair exposes patients to avoidable risks.

Medial versus lateral tears. There is no conclusive evidence as to whether or not the healing potential in the medial and lateral meniscus is different. Older reports suggested better healing potential in the lateral meniscus; however, more recent literature did not support these findings. Regardless of healing potential, it has been shown that lateral meniscectomy has more severe consequences than medial meniscectomy, and this should be considered in the decision-making process.

Vascularity. The outer third of the meniscus (the red-red zone) has the greatest healing potential owing to the presence of the perimeniscal capillary plexus. In contrast, limited healing capacity should be expected in the central and inner thirds, which are avascular and aneural. A distance of 0 to 2 mm of the tear from the menisco capsular junction has been identified as the greatest predictor for healing. Nevertheless, it has been shown that repairing tears in the avascular zones can also have good clinical outcomes in a high percentage of patients. ^,

Instability. Knee instability jeopardizes meniscal repair integrity and healing. Biomechanical and clinical studies have proved the protective effect of regaining knee stability by anterior cruciate ligament reconstruction (ACLR) on meniscal repairs. Surgeons must not rely only on physical examination and imaging to rule out instability, but must also assess it by examination under anesthesia before performing meniscal repair. When instability is diagnosed, it should be addressed, preferably at the same time the meniscus is repaired.

Concomitant ACLR. Multiple studies have reported higher healing rates of meniscal repairs in conjunction with an ACLR in comparison to isolated meniscal repairs. ^, Growth factors and pluripotent cells released after bone-tunnel drilling, as well as favorable mechanism of injury secondary to instability in comparison to isolated meniscal injury mechanisms, are acceptable theories. ^,

Recognition: No improvement or worsening of symptoms after the surgical intervention, failure of repair proven be physical examinations and imaging (magnetic resonance imaging [MRI], computed tomography [CT] arthrography).
Management: Thorough evaluation for of all aforementioned conditions. Repair failure because of poor patient selection will require a reoperation with partial meniscectomy.

Intraoperative Management

Surgical Technique

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