Arthroscopic Medial Meniscal Root Repair Using a Novel Re-Tensionable All-Suture Anchor

Abstract

Background:

Medial meniscal root repairs are devastating injuries that can cause long-term knee problems if not properly addressed. Some common issues when addressing these injuries surgically include the “bungee-cord” effect seen with implants that sit too far from the tibial plateau surface and loss of tension on the sutures after cycling of the knee after the repair. This video will discuss the presentation of a patient with a medial meniscal root repair treated with a novel technique to counteract these aforementioned issues.

Indications:

Based on the patient’s medial meniscal root tear and minimal arthritis seen on radiograph, he was indicated for a meniscal root repair to prevent meniscal extrusion and reinforce normal meniscal hoop stresses to limit progression of his arthritis.

Technique Description:

This technique uses a novel re-tensionable all-suture anchor through a transtibial tunnel with 2 repair sutures through the meniscal root that sits just below the tibial plateau, allowing the surgeon the ability to re-tension the implant after cycling the knee.

Results:

Arthroscopic repair of the medial meniscal root allowed the patient to return to his previous level of activity.

Discussion/Conclusion:

In this case, arthroscopic medial meniscal root repair can yield good results in patients to get them back to their previous level of activity while minimizing the chance of rapid arthritic progression that is typically seen with nonoperative management of these injuries.

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

In this video, we present a surgical technique for an arthroscopic medial meniscal root repair using a novel re-tensionable all suture anchor through a transtibial tunnel.

These are our disclosures.

The following topics will be covered in this video.

Our patient is a 54-year-old male who suffered an acute right knee injury when he lost his balance and took a large step down from a high porch. He felt a pop and had immediate right knee pain causing pain with weightbearing activities necessitating a cane. His symptoms did not improve despite conservative treatment in the form of rest, ice, and anti-inflammatory medications.

Weightbearing radiographs revealed mild medial compartment joint space narrowing but otherwise were normal.

Magnetic resonance imaging of his right knee demonstrates a root avulsion of the posterior horn of the medial meniscus and relatively well-preserved articular cartilage that can be seen on these coronal images.

Our final preoperative assessment was a right medial meniscal root avulsion, and he was indicated for a meniscal root repair due to his minimal arthritic changes seen on radiograph that would likely progress without surgical intervention.

The procedure was performed on an outpatient basis under general anesthesia. Requisite materials for a meniscal root repair are seen here. The patient was positioned supine using a Johnson operative leg holder.

Here we have our 54-year-old patient with an acute medial meniscal root tear that is unstable. You can see that the meniscal root is reducible to its anatomic insertion on the tibia. The footprint of the meniscal root is identified using a probe just slightly anterior to the posterior aspect of the tibial cortex. An Apollo radio frequency wand is then used to mark the footprint of the medial meniscal root on the tibial plateau. A tibial guide is then placed, and a 2.4-mm cannulated drill bit is drilled, creating a transtibial tunnel. The trocar from the cannula to the drill bit is then removed, being careful to remove any bone debris from the cannulation. A nitinol suture lasso is then placed through the central portion of the drill and retrieved out the medial portal. The lasso wire is then used to shuttle the re-tensionable all-suture anchor into the tibial tunnel until the most proximal portion of the anchor is seated just below the tibial plateau. Here we can see the implant being loaded into the nitinol wire, and it is then shuttled through the medial portal into the tibial tunnel. Now looking intra-articularly, we are pulling the implant retrograde into the tibial tunnel. As the final part of the implant is brought to the tunnel opening, care is taken with slight counter pressure held to ensure that the implant is seated just below the tibial cortex. A potential pitfall of this technique would be to pull too hard when trying to seat the implant, advancing the bulbous portion of the anchor too far into the tibial tunnel. Once the anchor is positioned, it is set using the looped tensioning suture on the tibial side of the anchor. The anchor is then checked to make sure that it is fully seated just below the tibial plateau. All of the sutures are then retrieved out of the lateral portal, except for the white repair suture. A grasper was used to show an anatomic reduction based on tibial tunnel placement. The repair suture is then passed through the torn meniscus root using a knee scorpion in a standard fashion. The striped conversion suture is then retrieved out the medial portal, and the white repair suture is converted into the re-tensionable all-suture anchor using the tensioning suture that is exiting the tibial tunnel. Most of the slack is removed from the suture, but it is not fully tensioned to allow passage of the second blue repair suture, which is then passed through the torn meniscal root in a similar fashion using the knee scorpion. This blue suture is then removed out of the medial portal, and once again, the corresponding striped conversion suture is retrieved out of the medial portal and the blue repair suture is passed through the re-tensionable all suture anchor and converted in the tibial tunnel. Slack is removed from the blue suture. We then remove slack from the white suture. If a small twist occurs during this process, a grasper can be introduced into the knee to remove any of the twisting from the suture and tensioning can occur. For final tensioning, an arthroscopic grasper is introduced through the medial portal to reduce the meniscus while final tensioning occurs. You can see excellent anatomic reduction and repair of the meniscal root with centralization of the entire meniscal body and the normal meniscal contour. The construct is extremely stable throughout the arc of motion from full extension to 90° of flexion.

Some of the potential complications of a medial meniscal root repair are listed here and include knee stiffness, lack of a full recovery, recurrence, progression of arthritis, infection, and neurovascular injury. ³

Postoperatively, the patient is placed in a range-of-motion knee brace locked in extension. For the first 4 weeks, partial weightbearing is allowed with flexion to 90°. After the fourth week, the patient is weaned from the brace, with advancement of motion and weightbearing as tolerated. Return to full activities typically is seen at 4 to 6 months. Postoperative medications prescribed include deep venous thrombosis chemoprophylaxis, typically in the form of aspirin, as well as a multimodal oral pain management protocol.

Some tips to optimize success with this technique include ensuring excellent visualization of the root insertion, which may necessitate a reverse notchplasty or pie-crusting of the medial collateral ligament. ² It is important to seat and lock the implant just below the tibial plateau, with a hand rolling maneuver helping to ensure this. Clamping unused sutures also helps to prevent accidental unloading of the anchor. Suture management is essential, with parking of the unused sutures through the lateral portal and only using your working stitch through the medial portal with a cannula. Appropriate final tensioning can be assisted with a grasper, with re-tensioning as needed after cycling the knee.

Features of this technique that make it unique compared to previous systems include the proximity of the implant to the meniscal-bone interface helping minimize the dreaded bungee cord effect, the option to pass 2 repair stitches with a single all suture anchor, and the re-tensionable option to truly dial in the repair to an anatomic state. ⁵

Regarding outcomes, long-term studies have shown the benefits of medial posterior meniscal root repair versus other treatment options. After 10 years, when compared to meniscectomy and nonoperative management, meniscal root repairs have shown significantly decreased osteoarthritis rates, conversion to total knee arthroplasty rates, and better cost-effectiveness.^1,4

From the Department of Orthopedic Surgery at Baptist Health South Florida, we thank you for watching.

Our references are listed here.