Meniscal Root Repair With Centralization

Abstract

Background:

Meniscal root tears compromise hoop stress resistance and lead to elevated tibiofemoral contact pressures, meniscal extrusion, and rapid progression of osteoarthritis. Prompt diagnosis and intervention are essential to prevent further degenerative changes.

Indications:

Meniscal root repair is indicated in patients with acute traumatic tears or chronic symptomatic root tears without advanced arthritis. Root repair has been shown to be beneficial regardless of the patient's age, even in the setting of early arthritis. Contraindications to root repair are severe osteoarthritis or poor surgical candidacy. Meniscus centralization is an important augment to the repair, particularly in the setting of meniscal extrusion.

Technique Description:

After diagnostic arthroscopy, visualization of the medial compartment is enhanced via controlled medial collateral ligament pie-crusting. The meniscal root footprint is decorticated, and the meniscotibial ligaments are released to mobilize the meniscus. Two luggage-tag sutures are placed across the tear and shuttled through a transtibial tunnel drilled to the native root footprint. A knotless anchor secures the repair. Centralization is achieved by placing a knotless all-suture anchor at the mid-coronal medial tibial plateau, with sutures passed in a mattress configuration through the meniscocapsular junction, preventing extrusion. Root sutures are then tensioned and fixed with the knee in 90° of flexion.

Results:

This anatomic transtibial repair with centralization has been shown to restore hoop stresses, reduce meniscal extrusion, and provide superior outcomes compared with meniscectomy or nonoperative management. Patients undergoing root repair report improved pain, function, and activity levels.

Discussion/Conclusion:

Transtibial meniscal root repair with centralization is a reproducible technique that restores meniscal function, minimizes extrusion, and delays the progression of osteoarthritis. The luggage-tag suture configuration mitigates suture cutout, and careful attention to centralization placement and tensioning optimizes outcomes. Postoperative rehabilitation should emphasize progressive weightbearing and strengthening, with return to sport typically achievable by 6 months. This approach provides durable symptom relief and joint preservation when applied to appropriately selected patients.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

Background

Meniscal root tears are radial tears within 1 cm of the root insertion or avulsions at the meniscal attachment. ¹² These injuries disrupt resistance to hoop stresses, leading to increased tibiofemoral contact pressures and accelerated osteoarthritis. ¹³ Meniscal extrusion occurs with root tears and is biomechanically analogous to a total meniscectomy. ¹ The standard treatment is a transtibial pullout repair of the posterior root ¹⁷ (Figure on slide ¹⁶ ). Centralization is an adjunct procedure performed to stabilize the meniscal body against extrusive forces^10,18 and has been shown to minimize meniscal extrusion. ⁴ Two case series showed maintenance of this protective effect at 2 years postoperatively,^14,20 and a more recent randomized control trial also showed significantly less postoperative extrusion at 6 months. ²⁶

Diagnosis can be challenging as patients often do not present with symptoms commonly seen with meniscal body tears. Instead, they often present with posterior knee pain with deep flexion and joint line tenderness. ³ Medial meniscal root tears are predominantly degenerative in origin, often occurring in the setting of osteoarthritis and varus deformity. Whereas lateral meniscal root tears are often traumatic with concomitant anterior cruciate ligament (ACL) injuries.^6,7

The case described in this video was a healthy 64-year-old male who injured his knee stepping off a ladder. He presented with 4 months of knee pain and swelling refractory to conservative management.

Specific features to look for in diagnosing root tears on magnetic resonance imaging (MRI) include a ghost meniscal sign on sagittal MRI, ³ linear defects on axial or coronal images indicating a complete tear, and meniscal extrusion >3 mm at the level of the medial collateral ligament (MCL), suggesting the need for centralization. ¹⁵

Indications

Treatment often favors surgical management. Meniscal root repair is indicated for patients without significant preexisting arthritis who have acute traumatic tears or chronic symptomatic meniscal root tears. ³

Partial meniscectomy is indicated only in patients with chronic, symptomatic tears and preexisting grade 3 or 4 arthritis who fail nonoperative management, and in patients with partial root tears with a substantial footprint intact (Figure on slide ¹⁶ ).

Patients with root tears frequently have elevated body mass index and are in poorer physical condition. Patient selection for operative versus nonoperative management should consider lifestyle factors, physiologic age, and ability to comply with postoperative rehabilitation restrictions.

Technique Description

Standard diagnostic arthroscopy is performed, followed by pie crusting of the MCL to increase visualization of the medial compartment. The MCL is palpated while applying valgus stress at 10°, and the scope is used to identify the mid coronal plane of the body of the meniscus. An 18-G spinal needle is inserted here and 1 cm distal to the joint line to avoid the joint and fluid extravasation. The needle is pushed into the periosteum while the MCL is tensioned with valgus stress. The needle may be turned obliquely to achieve a greater release, which is confirmed by feeling a pop with valgus stress.

The torn root is then visualized, and the footprint is decorticated with a curved curette to expose bleeding bone. A spatula is used to free up the meniscotibial ligaments along the posterior horn to the midbody of the meniscus. A meniscal rasp is used to stimulate more bleeding, and a shaver is used to remove chondral fragments and freshen the torn root edges.

Two luggage tag sutures are placed using a suture passing device that is positioned parallel to the radial tear. One is positioned as close as possible to the edge of the tear, and the next just medial to that. A 0 suture or suture tape can be used for a lower profile. The luggage tag configuration helps prevent suture cutout.

A variable-angle aiming arm device set to 55° is positioned with the exit at the footprint and entry on the proximal medial tibial plateau. If the procedure is being performed with a concomitant ACL reconstruction, the root repair tunnel can be positioned distal to the ACL tunnel or on the lateral proximal tibia to avoid interference with the ACL tibial tunnel (Figures on slide^5,17).

After a skin incision is made for the aiming bullet, the tunnel is drilled with a 2.3-mm guide pin. The aiming guide is removed, and the guide pin is then overreamed with a 4.5-mm cannulated reamer. The guide pin is then removed, and a suture passing device is placed into the tibial tunnel through the reamer and grasped through the anteromedial portal, along with the suture passing device to ensure there are no soft tissue bridges. Root sutures are then passed down the tibial tunnel and often exit just proximal to the pes tendons.

Centralization is done before tensioning the root sutures. A spinal needle is used to assess the trajectory to the mid coronal segment of the medial edge of the medial tibial plateau. An accessory superomedial portal is made adjacent to the patella. The guide for a knotless all-suture anchor is placed through the accessory superomedial portal and aimed at the described trajectory. The anchor hole is drilled and cycled at least 3 times to ensure proper opening, and then the suture anchor is malleted into place through the guide and tugged to set into place. A canula is placed in the lateral portal, and the scope camera is switched to the anteromedial portal. The blue suture and the tubular white suture are grasped through the lateral canula and loaded onto an angled suture passing device, starting with the blue suture. The blue suture is passed through the meniscocapsular junction, followed by the white suture, which is passed just anterior to that to create a mattress configuration. The blue suture is passed into the looped suture, and the remaining limb from the suture anchor is pulled out through the accessory superomedial portal at the same trajectory of insertion to secure the knotless suture anchor. A probe can be placed underneath the mattress suture along the meniscocapsular junction to be used as a counterforce, to help direct the loop and prevent overtightening. It should be tensioned just to the point where it is difficult to pass a probe underneath.

Attention is turned back to the root repair sutures. A knotless bone anchor is placed just lateral to the exit of the tibial tunnel. The root repair sutures are secured in the anchor with the knee in 90° of flexion and under direct visualization with the scope, then tied over the suture anchor device. The final tensioning of the repair is confirmed arthroscopically.

Notch microfracture is performed at the end of the case for biologic augmentation. The decortication of the footprint described at the beginning of the case also provides marrow augmentation directly at the fixation site. The author prefers these more cost-effective strategies over bone marrow aspirate concentrate or platelet-rich plasma procedures for biologic augmentation.

Pitfalls, Tips, and Tricks

Adequate exposure of the posterior root is critical and can be a major pitfall. If sufficient clearance (ie, ≥1 probe length) is not achieved, pie crusting of the superficial (sMCL) is recommended. The authors prefer pie crusting at the proximal tibia with the knee in valgus, localizing the mid-coronal joint line under arthroscopic visualization. The tactile “crunch” of sMCL fibers helps confirm correct placement; the feel of the periosteum without the crunch suggests that the needle may be too anterior.

If visualization of the footprint remains limited, the Gillquist maneuver can improve access to the posteromedial compartment, or limited burring of the medial tibial eminence can enhance visualization.

Accurate identification of the anatomic footprint is essential for guide pin placement. Decortication with a curved curette helps define the footprint. If alignment is suboptimal, using the contralateral aiming arm may improve the trajectory.

Soft -tissue bridges can further complicate the procedure. Use of a cannula in the anterolateral portal helps prevent suture entanglement, and a C-shaped grasper can be used to confirm suture management. An angled self-capturing suture device also helps facilitate access to the meniscocapsular junction.

Alternative Techniques

The optimal technique for root repair and centralization remains controversial. Aperture fixation using an adjustable suture anchor at the footprint has been proposed as an alternative to transtibial tunnel fixation, with promising early biomechanical results.^2,21 Various root suture configurations have also been described, including luggage tag, simple sutures, and ripstop constructs. ²⁵

Similarly, significant variability exists in reported centralization techniques. ²⁴ Some studies suggest that a single centralization suture is insufficient, advocating for multiple sutures and emphasizing restoration in the horizontal plane.^9,23 An alternative approach involves fixation of the meniscotibial ligament using suture anchors to cinch the ligament to the tibial plateau. ¹¹

Results

After root repair, range of motion (ROM) is restricted from 0° to 90° for the first 2 weeks, and patients are touch-down weightbearing in a hinged knee brace for 6 weeks.

After 6 weeks, they should have full active ROM and gradually progress to full weightbearing without crutches by week 8, when they can start working on closed-chain lower extremity strengthening exercises.

At 10 weeks, patients should have full ROM and be fully weightbearing with a normal gait pattern. Depending on baseline activity level, they can begin sport-specific drills around 3 months until cleared to safely return to sport, which most studies report can be allowed at 6 months postoperatively. ⁸ However, patients are typically older nonathletes and are unable to return to activities such as jogging until around 4 to 6 months. Although several protocols have been published (Figure on slide ¹⁸ ), there are no standardized guidelines for rehabilitation, ²² and protocols often vary based on the institution and patient population.

Discussion/Conclusion

Overall, anatomic transtibial posterior meniscal root repair results in improved function, pain, and activity independent of patient age and root tear laterality. Root repair has been shown to result in significantly decreased joint space narrowing over time as well as superior patient-reported outcomes when compared with both meniscectomy and nonoperative management. ¹⁹