After an initial meniscus root repair, failure to properly secure the meniscus root to the tibia can lead to several symptoms. Some of the most common failure symptoms include re-tearing of the meniscus root tear, which is reported in up to 20% of cases, even under optimal conditions.
Additional failure symptoms may include:
- Suture Pullout – Sutures used to repair the meniscus root may pull through the meniscus during rehabilitation, causing re-tearing. The most common sites for suture pullout include the tibial tunnel, where the sutures enter the bone, and the meniscofemoral groove.
- Progressive Meniscal Extrusion – The meniscus may extrude or protrude outward through the tibial tunnel, leading to additional stress on the previously healing root tear. Progressive extrusion can result in further meniscal degeneration, and in some cases, may even compromise the ACL graft integrity.
- Cartilage Loss and Subchondral Insufficiency Fractures – Failure of the meniscus root repair can lead to further cartilage loss and subchondral bone insufficiency fractures. These fractures can occur around the site of the original tear or at distant locations due to increased loads on the bone beneath the repair site.
- MRI Changes After Repair – Following a meniscus root repair, there may be signs of repair failure on MRI. These can include discontinuity of the sagittal and coronal planes on the MRI, which may suggest a re-tear. Additionally, there may be signal intensity changes in the meniscus root or surrounding bone.
- Painful or Limited Motion – After a failure of repair, patients may report persistent or new pain and limited motion due to excessive load and stress placed on the knee, particularly during weightbearing activities like walking or kneeling.
- Unpredictable Outcome – Meniscus root repairs may sometimes have unpredictable outcomes, with some patients experiencing worsening pain and reduced functionality despite seemingly successful repairs. These failures can be particularly disheartening for patients and their treatment providers.
- Recurrent Injury – Despite initial repair, meniscus root tears may still occur in the future. Repeated or recurrent root tears may lead to increased functional limitations and the potential for further cartilage damage and OA.
- Worsening of Pre-existing Arthritis – Repair efforts may also exacerbate pre-existing knee arthritis, particularly in older patients. While the meniscus may initially recover from the primary injury, ongoing OA may worsen as the knee joint sustains increased repetitive insults.
It is essential to recognize these symptoms promptly and initiate a prompt diagnostic workup. The initial diagnostic modalities can include physical examination, imaging studies like MRI, aspiration of the knee joint to rule out other causes of swelling, and in some instances, diagnostic arthroscopy. Once a diagnosis is made, treatment should be tailored accordingly, aiming to manage any mechanical pain, restore normal motion, optimize healing prospects, and prevent further injury.
Defective Meniscus Repair
A defective meniscus repair occurs when the sutures used to approximate the meniscus root and reposition it into its proper anatomic position begin to loosen or separate over time during the six weeks it takes for the body to properly heal the injury. This happens due to the tensile forces applied during knee bending (flexion) or other activities, which exert constant pull on the sutures over a short period, leading to separation or slippage of the sutures.
Surgical Techniques
When contemplating a meniscus root repair, different surgical techniques are employed based on the characteristics of the tear and the patient's history. Some of the most commonly performed techniques are:
Transtibial Pullout Repair
Transstibial meniscus root repair involves the placement of sutures into the torn meniscus root and shuttle them through a tunnel in the tibia. The sutures are then tied over a button on the anterior cortex of the tibia. The main advantage of this approach is that it allows for direct access to the root tear without requiring an anterior approach to the knee joint.
One-Tunnel vs. Two-Tunnel Techniques
In recent years, the two-tunnel technique has become increasingly popular as it allows for a larger surface area of the meniscus to engage with the decorticated bone. This may lead to improved healing rates by providing a more solid and secure repair.
Double Locking Loop Stitch
The double locking loop stitch, invented by Dr. Justin Saliman, provides the strongest suture pattern possible for meniscus repair. By passing the suture twice through the meniscus root and into the tibia, it minimizes the risk of failure and optimizes pull-through strength.
Post-Operative Care and Rehabilitation
Post-operatively, patients should undergo a careful exercise regimen that includes weightbearing restrictions until the meniscus root has healed. The duration of the nonweightbearing period varies based on surgical technique, but it typically ranges from 4 to 6 weeks for transstibial repairs. The role of physiotherapy in meniscus root repair is crucial for recovery and includes active stretching and strengthening exercises, as well as protection of the repair site.
Failed Meniscus Root Repair
In cases where a meniscus root repair fails, patients may experience persistent or worsening symptoms. Treatment can vary depending on the underlying causes of the failure, including re-tearing of the meniscus root tear, progressive meniscal extrusion, or other mechanisms. These failures may necessitate further diagnostic workup and potential revision repairs or total knee replacements, respectively. Effective management of meniscus root failures requires a comprehensive approach that encompasses early recognition, accurate diagnosis, and prompt, appropriate treatment.
