Type II Medial Meniscus Root Repair With Peripheral Release for Addressing Meniscal Extrusion

Meniscocapsular release technique to reduce chronic and challenging bucket-handle meniscus tear

Several surgical procedures for the repair of bucket handle meniscus tears have been reported in the literature. However, even the most skilled surgeon can find it difficult to treat chronic and locked lesions, which typically result in meniscectomies. Therefore, a repair method for bucket-handle meniscus tears that are chronic and locked is shown, along with a case series where this procedure was used. The technique consists of a release of the joint capsule attachment to the meniscal body, which increases the mobility of the meniscus and facilitates the reduction of the injury, allowing subsequent repair through a combination of both all-inside and inside-out repair techniques. The main objective of this technique is to reduce the need for meniscectomies in difficult cases of bucket-handle meniscus tears, protect the meniscal tissue, and slow the progression of osteoarthritis in the process.

Measuring Technique for Meniscal Extrusion Using Ultrasound in the Setting of Posterior Medial Meniscal Root Tears

Meniscal extrusion (ME) is a valuable, noninvasive diagnostic tool for meniscus pathology. In addition, ultrasound can allow for instant results in the office. However, ME is a fragile metric in the degree of millimeters. The inconsistent techniques used by different authors in the literature and the additional operator variability that ultrasound technology introduces make it important a systematic approach is used. The purpose of this study is to propose a reproducible technique. The current authors recommend having the patient in (1) 30° of knee flexion while weight-bearing, (2) capturing the image at the posterior border of the medial collateral ligament, (3) using a reference line parallel to the articular margin of the tibia, and (4) measuring ME at the coronal midpoint of the outermost edge of the meniscus.

Clinical and radiologic outcomes in patients with meniscal root tears

BACKGROUND

Meniscal root tears can lead to early knee osteoarthritis and pain. This study aimed (1) to compare clinical and radiological outcomes between patients who underwent arthroscopic meniscal root repair after meniscal root tears and those who received non-surgical treatment, and (2) to identify whether baseline MRI findings could be potential predictors for future treatment strategies.

METHODS

Patients with meniscal root tears were identified from our picture archiving and communication system from 2016 to 2020. Two radiologists reviewed radiographs and MRI studies using Kellgren-Lawrence (KL) grading and a modified Whole Organ MRI Scoring (WORMS) at baseline and follow-up. The median (interquartile range [IQR]) of follow-up radiographs and MRI studies were 134 (44-443) days and 502 (260-1176) days, respectively. MR images were assessed for root tear-related findings. Pain scores using visual analogue scale (VAS) and management strategies (non-surgical vs. arthroscopic root repair) were also collected. Chi-squared tests and independent t-tests were used to assess differences regarding clinical and imaging variables between treatment groups. Logistic regression analyses were performed to evaluate the associations between baseline MRI findings and each future treatment.

RESULTS

Ninety patients were included. VAS pain scores were significantly (p < 0.01) lower after arthroscopic repair compared to conservative treatment (1.27±0.38vs.4±0.52) at the last follow-up visit with median (IQR) of 325 (180-1391) days. Increased meniscal extrusion (mm) was associated with higher odds of receiving non-surgical treatment (OR = 1.65, 95%CI 1.02-2.69, p = 0.04). The odds of having arthroscopic repair increased by 19% for every 1 mm increase in the distance of the tear from the root attachment (OR = 1.19, 95% CI: 1.05-1.36, p < 0.01). The odds of undergoing arthroscopic repair were reduced by 49% for every 1 mm increase in the extent of meniscal extrusion (OR = 0.51, 95% CI: 0.29-0.91, p = 0.02) as observed in the baseline MRI.

CONCLUSIONS

Patients who underwent arthroscopic repair had lower pain scores than patients with conservative treatment in the follow-up. Distance of the torn meniscus to the root attachment and the extent of meniscal extrusion were significant predictors for arthroscopic repair in the next three weeks (time from the baseline MRI to the surgery date).

Medial Meniscus Posterior Root Tear: How Far Have We Come and What Remains?

Medial meniscus posterior root tears (MMRTs), defined as tears or avulsions that occur within 1 cm of the tibial attachment of the medial meniscus posterior root, lead to biomechanically detrimental knee conditions by creating a functionally meniscal-deficient status. Given their biomechanical significance, MMRTs have recently been gaining increasing interest. Accordingly, numerous studies have been conducted on the anatomy, biomechanics, clinical features, diagnosis, and treatment of MMRTs, and extensive knowledge has been accumulated. Although a consensus has not yet been reached on several issues, such as surgical indications, surgical techniques, and rehabilitation protocols, this article aimed to comprehensively review the current knowledge on MMRTs and to introduce the author's treatment strategies.

Quantifying Meniscal Extrusion Using Ultrasound in the Setting of Concomitant Cadaveric Knee Lesions: Part I: The Medial Meniscotibial Ligament and Posterior Medial Meniscal Root

PURPOSE

1. Evaluate how the meniscotibial ligament (MTL) affects meniscal extrusion (ME) +/- concomitant posterior medial meniscal root (PMMR) tears. 2. Describe how ME varied along length of meniscus.

METHODS

ME was measured using ultrasonography in 10 human cadaveric knees in conditions: (1) control, either (2a) isolated MTL sectioning, or (2b) isolated PMMR tear, (3) combined PMMR + MTL sectioning, and (4) PMMR repair. Measurements were obtained 1 cm anterior to the MCL (anterior), over the MCL (middle), and 1 cm posterior to the MCL (posterior) +/- 1000N axial loads in 0° and 30° flexion.

RESULTS

At 0°, MTL sectioning demonstrated greater middle than anterior (P<0.001) and posterior (P<0.001) ME, while PMMR (P=0.0042) and PMMR+MTL (P<0.001) sectioning demonstrated greater posterior than anterior ME. At 30°, PMMR (P<0.001) and PMMR+MTL (P<0.001) sectioning demonstrated greater posterior than anterior ME, and PMMR (P=0.0012) and PMMR+MTL (P=0.0058) sectioning demonstrated greater posterior than anterior ME. PMMR+MTL sectioning demonstrated greater posterior ME at 30° compared to 0° (P=0.0320). MTL sectioning always resulted in greater middle ME (P<0.001), in contrast with no middle ME changes following PMMR sectioning. At 0°, PMMR sectioning resulted in greater posterior ME (P<0.001), but at 30°, both PMMR and MTL sectioning resulted in greater posterior ME (P<0.001). Total ME surpassed 3 mm only when both the MTL and PMMR were sectioned.

CONCLUSION

The MTL and PMMR contribute most to ME when measured posterior to the MCL at 30° of flexion. ME greater than 3 mm is suggestive of combined PMMR + MTL lesions.

CLINICAL RELEVANCE

Overlooked MTL pathology may contribute to persistent ME following PMMR repair. We found isolated MTL tears able to cause 2-2.99 mm of ME, but the clinical significance of these magnitudes of extrusion is unclear. The use of ME measurement guidelines with ultrasound may allow for practical MTL and PMMR pathology screening and pre-operative planning.

Clinical significance and management of meniscal extrusion in different knee pathologies: a comprehensive review of the literature and treatment algorithm

The menisci are crescent-shaped, fibrocartilaginous structures that play a crucial role in the load transition and distribution of the contact forces along the tibiofemoral articulation. Meniscal extrusion (ME) is a radiological finding, especially in magnetic resonance imaging (MRI) scans, for which there has been growing interest in recent years. ME, in the coronary plane, is defined as the maximum distance of the most distal end of the meniscus from the border of the tibial plateau, where the tibial eminences are the most prominent, without taking into account the osteophytes. Although there is still controversy in the literature in respect of the optimal cutoff value, a threshold of 3 mm is considered significant. ME has no specific clinical finding or sign and it is encountered in many knee pathologies. It is associated with either rapidly progressive knee osteoarthritis or early onset of knee osteoarthritis and increased morbidity. In this review, we delineate the clinical significance of ME in various knee pathologies, as well as when, why and how it should be managed. To the best of our knowledge, this is the first study to elaborate on these topics.

Meniscal Root Tears: A Decade of Research on their Relevant Anatomy, Biomechanics, Diagnosis, and Treatment

A foundational knowledge of the anatomy and biomechanics of meniscal root tears is warranted for proper repair of meniscal root tears and for preventing some of their commonly described iatrogenic causes. Meniscal root tears are defined as either a radial tear occurring within one cm of the root attachment site of the meniscus or a complete bony or soft tissue avulsion of the root attachment altogether. Meniscal root tears disrupt the protective biomechanical function of the native meniscus. Biomechanical analyses of the current techniques for meniscal root repair highlight the importance of restoring menisci to their correct anatomic orientation, thereby restoring their biomechanical function. A comprehensive understanding of the clinical and radiographic presentations of these injuries is critical to preventing their underdiagnosis. The poor long-term outcomes associated with conservative treatment measures, namely, ipsilateral compartment osteoarthritis, warrants the surgical repair of meniscal root tears whenever possible. While excellent patient-reported outcomes exist for the various surgical repair techniques, adherence to stringent post-operative rehabilitation protocols is critical for patients to avoid damaging the integrity of a repaired root. This review will focus on current concepts pertaining to the anatomy, biomechanics, diagnosis, treatment, and postoperative rehabilitation for meniscal root tears.

The Natural History of Medial Meniscal Root Tears: A Biomechanical and Clinical Case Perspective

Posterior medial meniscus root tears (PMMRTs) make up a relatively notable proportion of all meniscus pathology and have been definitively linked to the progression of osteoarthritis (OA). While known risk factors for development of OA in the knee include abnormal tibial coronal alignment, obesity and female gender, PMMRTs have emerged in recent years as another significant driver of degenerative disease. These injuries lead to an increase in average contact pressure in the medial compartment, along with increases in peak contact pressure and a decrease in contact area relative to the intact state. Loss of the root attachment impairs the function of the entire meniscus and leads to meniscal extrusion, thus impairing the force-dissipating role of the meniscus. Anatomic meniscus root repairs with a transtibial pullout technique have been shown biomechanically to restore mean and peak contact pressures in the medial compartment. However, nonanatomic root repairs have been reported to be ineffective at restoring joint pressures back to normal. Meniscal extrusion is often a consequence of nonanatomic repair and is correlated with progression of OA. In this study, the authors will describe the biomechanical basis of the natural history of medial meniscal root tears and will support the biomechanical studies with a case series including patients that either underwent non-operative treatment (5 patients) or non-anatomic repair of their medial meniscal root tears (6 patients). Using measurements derived from axial MRI, the authors will detail the distance from native root attachment center of the non-anatomic tunnels and discuss the ongoing symptoms of those patients. Imaging and OA progression among patients who were treated nonoperatively before presentation to the authors will be discussed as well. The case series thus presented will illustrate the natural history of meniscal root tears, the consequences of non-anatomic repair, and the findings of symptomatic meniscal extrusion associated with a non-anatomic repair position of the meniscus.

Arthroscopic Transtibial Pull-Out Repair of Medial Meniscus Posterior Root Tear With a Whip Running Suture Technique

Medial meniscus posterior root tear is a disruptive injury causing significant sequelae. Several techniques to repair and maintain the native function of the medial meniscus have been introduced, but limitations have been reported in terms of their results. In this current note, the authors introduce the arthroscopic transtibial pull-out repair with whip running suture technique, which may not only avoid the potential risk of meniscus cut-through by the suture material but also optimize the reduction of the extruded meniscus. By suturing the posteromedial capsule and peripheral meniscus, more medialization force can be directly applied to the extruded part of the meniscus, and normal hoop tension can be restored.

Peripheral Stabilization Suture to Address Meniscal Extrusion in a Revision Meniscal Root Repair: Surgical Technique and Rehabilitation Protocol

Meniscal root tears are an increasingly recognized condition. These tears can cause the meniscus to become extruded outside the joint, which can diminish the biomechanical functionality of the meniscus. Anatomic repair of the meniscal root has previously been described, but this surgical procedure may not adequately address severe extrusion of the meniscal tissue. Additionally, when a primary anatomic repair fails, meniscal extrusion can increase, which can possibly accelerate joint degeneration if untreated. Therefore, the purpose of this Technical Note is to describe our surgical technique for revision medial meniscal root repair with a peripheral stabilization suture to address medial meniscal root tears with severe meniscal extrusion.

Medial Meniscus Root Repair in Patients With Open Physes

Meniscal root tears have become increasingly recognized in the past decade. Lateral meniscus root tears typically occur in active, younger patients who sustain acute anterior cruciate ligament tears. Conversely, medial meniscus root tears typically occur in isolation and affect middle-aged patients. However, recent reports have described the incidence of meniscal root tears occurring in pediatric populations who are skeletally immature. The purpose of this technical note is to describe the authors' surgical technique for medial meniscal root repair for patients with open physes.

Editorial Commentary: Comparing Medial and Lateral Meniscal Root Tears Is Like Comparing Apples and Oranges

The importance of treating meniscal root tears has been increasingly recognized, and surgeons have to make conscious decisions routinely regarding repair for select patients. The clinical and patient demographic differences between medial and lateral meniscal root tears are important and ultimately leave us wondering whether outcome differences are due to unique anatomic factors or the patient population sustaining these injuries.