Meniscal Root Injury

The root attachments of the posterior horns of the medial and lateral meniscus are very important for joint health.  When these are torn, the loading of the joint is equivalent to having no meniscus on the affected side.  Thus, these patients can often have early onset arthritis, the development of bony edema, insufficiency fractures, and the failure of concurrent cruciate ligament reconstruction grafts.  For this reason, much research has gone in to meniscus root repairs over the last several years.

Description of a Meniscus Root Repair

The technique of a meniscus root repair involves isolating the root, placing a minimum of 2 sutures in the remaining meniscal attachment, and trying to reposition it back to a more anatomic position.  In some instances, the meniscus posterior horn may need to be released from scar tissue to allow it to be repositioned.  This is important because these repairs are still quite tenuous with current technology, so it is important to try to put the meniscus back into a position where there would not be a lot of tension on the repair with knee range of motion.

After sutures are placed arthroscopically into the meniscal attachment, a small diameter tunnel, usually 5 millimeters in size, is reamed to the meniscal root attachment site, the sutures are pulled down the tunnel, and tied over a button on the anterior cortex of the tibia.  One should assess the range of motion at that point in time that can be performed in a “safe zone” to make sure that the physical therapist does not flex them harder in this time frame.

Are you a candidate for a meniscal root repair?

There are two ways to initiate a consultation with Dr. LaPrade:

You can provide current X-rays and/or MRIs for a clinical case review with Dr. LaPrade.

You can schedule an office consultation with Dr. LaPrade.

Request Case Review or Office Consultation

(Please keep reading below for more information on this treatment.)

Post-Operative Protocol for Meniscus Root Repair

Progression of range of motion is more limited than for a standard meniscus root repair, usually limiting patients to 0-60 or 0-90 degrees range of motion for the first 4 weeks and then slowly increasing range of motion as tolerated. Patients are allowed to initiate weightbearing at 6 weeks, but should avoid any significant squatting, squatting and lifting, or sitting cross-legged for a minimum of 5-6 months.  They may start the use of a stationary bike, and may slowly wean off crutches starting at 6 weeks post-operatively.

The results of meniscus root repairs in the literature are encouraging, but more improvement is necessary in the future.  Repairs have been found to delay or improve the findings of bony edema and the early onset of arthritis in many patients.  It has been found that one suture alone for the repair does not work well, so a minimum of 2 sutures is required to maximize meniscal healing.  Further study into meniscus root tears and radial root tears is ongoing by our research laboratory to try to improve the treatment of these complex problems.

Related Studies

Meniscus Root Repair FAQ

What is a meniscus root repair?

A meniscus root repair is a meniscus repair that restores the bony attachment of the meniscus.  It is different than other types of meniscus repairs which will sew a meniscus tear into the joint lining or capsule.  The meniscus root repair has to be tacked down to bone.  Most meniscus root repairs occur by placing sutures in the root tear and then shuttling them down a tunnel where the suture is tied over the front part of the tibia.

Meniscus root repair-why, when, and how?

A meniscus root repair is almost always performed because we know that if a meniscus root tear is not repaired it can lead to arthritic changes, with many patients needing a total knee replacement within 2-5 years.  We also know trimming a meniscus root tear is effectively the same as not doing anything for it, so it should be repaired in the right patient.

Patients who should consider a meniscus root repair include those with very minimal arthritis, who are strong enough to undergo 6 weeks of nonweightbearing on crutches, and have a reparable meniscus root tear.

Meniscus roots are repaired by following several steps.  First, one needs to confirm that there is a reparable meniscus root tear present.  Next, it is important to release the meniscus root away from a scar tissue which could hold it in the back of the knee and prevent it from having its normal function.  We have had award winning studies which have demonstrated that repairing a meniscus root in a nonanatomic position is equivalent to not repairing it at all, so the scar tissue needs to be released so the meniscus root can be pulled back into a more anatomic position.  Next, the cartilage over the repair site must be removed so that there is a bony bed of exposed bone for the meniscus to be pulled down into.  This optimizes the chance the meniscus root repair will heal.  Next, small tunnels can be drilled up into the prepared bony bed to pass sutures down.  A small self-passing meniscus repair device is then used to pass sutures in the end of the meniscus tear which are then shuttled down these cannulas.  They can be then tied over a button on the front part of the tibia to complete a root repair.  While some people have advocated tying these sutures directly to the bone, we have found out in our biomechanical studies that the suture can cut into the bone and loosen the repair over time so we do not recommend this.  We recommend that they be directly tied over a button to minimize the sutures in the repair stretching out over time.

Meniscus root tear versus ACL

An ACL tear most commonly occurs from a turning, twisting, or deceleration mechanism in a noncontact mode.  Meniscus root tears usually occur in patients with deep flexion such as skiers, or home gardeners, plumbers, or carpet layers or people doing similar activities.  An ACL tear commonly has a pop on the outside of the knee, whereas a patient who has meniscus root tear commonly feels a pop in the back of the knee.

It is important to recognize that most patients who sustain isolated meniscus root tears happen with a medial meniscus root attachment.  Patients who have an ACL tear have a 10% chance of having a lateral meniscus root tear.  These are totally different.  Lateral meniscus root tears can lead to arthritis, but they also result in the ACL being a little looser and the clunk that comes with an ACL tear (pivot shift) being more unstable.  Thus, when one does sustain a lateral meniscus root tear with an ACL tear, consideration should be given to having a concurrent lateral meniscus root repair so the ACL graft does not stretch out.

NOTICE: Effective June 1, 2019, Dr. LaPrade will be practicing at Twin Cities Orthopedics in both the Edina and Eagan Minnesota Clinics and Surgery Centers

Learn How We Can Help You Stay Active

Request a Consultation