Injury to or removal of meniscal tissue is associated with wear on the articular cartilage that lines the ends of the bones, knee instability and progression of osteoarthritis. Isolated traumatic tears are common in young, active male and female athletes aged 30 – 50. Age-related degenerative tears affect men and women aged 50-70. Many times, a meniscus tear occurs along with a torn ACL ligament. Meniscus transplants are not available for patients with a torn ACL.
In young and active patients with meniscus tears the goal of treatment is the preservation of the meniscus. Even a small tear increases the risk of future joint deterioration.
Current treatment options include a meniscectomy (a trimmed or removed meniscus) or meniscus repair to alleviate pain and restore function. Meniscus repair is an ideal solution, when possible, to restore normal knee function and preserve the joint. A partial meniscectomy may be recommended when a meniscus tear is unable to be repaired, to alleviate symptoms and restore function.
However, when a young and active patient experiences pain after surgery, the meniscus is irreparable, and there is little to no arthritis, a meniscus transplantation is a safe and reliable procedure. The goal is to restore function before the articular cartilage at the ends of the bones is worn away resulting in osteoarthritis; and to avoid a knee replacement.
Older patients with a torn meniscus often have persistent knee pain and arthritis. In these patients with degenerative or traumatic tears, surgical repair or trimming are not options; rather, the solution is a knee joint replacement.
The meniscal allograft transplant (MAT)
The MAT is a joint preservation procedure. The goal is to replace a severely degraded meniscus with a transplanted meniscus obtained from a donor. The transplant can restore knee biomechanics and function, relieve pain and prevent or delay knee joint degeneration and osteoarthritis. MAT is a procedure for patients who have lost their meniscus and have persistent symptoms in select patients.
Indications for MAT include:
- patients younger than age 55 who are physically active and have persistent pain that limits their ability to participate in desired activities
- who have had a partial meniscectomy or an irreparable tear
- with stable knee ligaments and
- no articular cartilage wear or arthritis, and are at a healthy weight
MAT is performed on carefully selected patients who are under age 50 with early post traumatic arthritis; and for patients with large irreparable tears who are symptomatic.
Dr. Godin will review your medical history, discuss your symptoms and conduct a comprehensive physical exam of both knees, checking alignment and gait and any other conditions that could impact the decision to recommend a transplant and/or require a procedure to protect the transplant. He will order imaging studies of both knees to evaluate all knee structures including the knee ligaments.
The donor allograft
The donor tissue is safety tested to specific standards set by the Food and Drug Administration and the American Association of Tissue Banks.
Generally, MAT is performed as minimally invasive arthroscopic surgery under general or regional anesthesia. Several punctures are made in and around the knee joint to insert the arthroscope and the miniature surgical tools. The transplant is sized and inserted into the joint through another incision. The implant is fixed to the bone and sutured into place. If there are other defects or damage to other tissues, that repair is accomplished before or in addition to the MAT.
Complications are rare. The risks of the procedure are those common to surgery in general including bleeding, infection and injury to surrounding tissues. If the transplant is subsequently frayed or torn, the treatment is similar to that of a natural meniscus.
Post-operatively the patient will wear a knee brace and use crutches for 4-6 weeks. Physical therapy for 2-3 months will focus on flexibility, range of motion and strength. Return to play can take 6-9 months.
MAT is a salvage procedure for patients who have undergone one or more prior operations, or the tear cannot be repaired, and the patient has no other options. The goal is to save young and active patients from the need for a total knee replacement.
Contact the Steadman Clinic to schedule a consultation with Dr. Jonathan Godin, the orthopedic surgeon and sports medicine expert.
1- Ridley TJ, McCarthy MA, Bollier MJ, Wolf BR, Amendola A. Age Differences in the Prevalence of Isolated Medial and Lateral Meniscal Tears in Surgically Treated Patients. Iowa Orthop J. 2017;37:91-94.