Meniscal damage within the knee continues to be a major problem seen by orthopaedic surgeons. Damage to the meniscus can lead to degenerative joint changes of the knee and has required that surgeons find alternative ways to slow this process. A lack of a meniscus significantly increases the amount of force on the articular surface of the knee. Over time, this increase in force results in degeneration of the cartilage and degenerative arthritis. Approximately 80% of patients with a whole meniscus removed develop significant arthritis in that compartment of the knee within 20 years. Frequently, patients develop the symptoms of arthritis, pain and swelling of the knee, within a few months to years after the meniscus is removed. Meniscal replacement, with a matched size donor allograft meniscus, are used to treat the symptoms of their early arthritis.

Indications

Patients with pain following meniscectomy who are young, active and have minimal degenerative joint changes are good candidates for the meniscal allograft procedure. In addition, the patient must not be more than grade 2 chondromalacia of the joint compartment, no ligamentous instability, or any malalignment (knock knees (valgus) or bow legs (varus)) of the affected knee compartment. X-rays can be taken to determine the amount of degenerative changes and the extremity alignment in the patient. These x-rays are used to determine the size of the allograft needed by using standard sizing markers. The radiographs are then used to find a matching donor meniscus for the patient.

Procedure

A meniscal allograft reconstruction is usually performed with arthroscopic assistance. Arthroscopic instruments are used to remove the remainder of any portions of the meniscus to its outer rim. Meanwhile, the meniscus is prepared on the back surgical table to fit into the joint. For the medial meniscus, the meniscal attachments are prepared with small cores of bone. The lateral meniscal attachments are too close to each other to have separate bone plugs, so a trough of bone including both attachments is prepared. Once the bony attachments have been prepared and sized, the tunnels or trough to fit the meniscal bony attachments are prepared with arthroscopic assistance in the knee. A small arthrotomy incision is then made along the patellar tendon to fit the meniscus in the joint. The meniscus is both pushed into the joint by the surgeon, and pulled into it by sutures in the back horn of the meniscus, which exit the back of the knee through arthroscopic portals. The meniscus is then attached to the remaining original meniscal rim or joint capsule by arthroscopic tacks or sutures. Once the meniscus is found to be stable to probing, the surgical incisions are then closed.

Rehabilitation

Standard protocol for meniscal allograft procedure

FAQ's

Q1. How is a donor graft selected?

A1. The graft is sized to the patient based on the size of his/her tibia: The donor graft commonly comes from young organ donors (usually motor vehicle accidents).

Q2. Is the donor specimen tested for disease?

A2. Yes. The specimen is tested for infection from both bacteria and viruses.

Q3. Will my medical insurance cover this procedure?

A3. Individual insurance plans may vary however, it is important for the surgeon to document pain, swelling, progression of arthritis or other signs or symptoms which could be benefitted by a meniscal allograft procedure.

Q4. How long is the recovery period for this operation?

A4. 4-6 months to allow donor site to heal and regain sufficient strength.

Q5. Will I be able to bear weight on this leg?

A5. Patients are non weight bearing for 6 weeks.At this point, patients are allowed to wean off crutches as telerated.

Q6. Will I need to be hospitalized?

A6. This procedure is usually done as an outpatient when this is the only procedure performed. Patients may require hospitalization if this surgery is done with another procedures (ACL reconstruction, ACI implantation, proximal tibial osteotomy, or fresh osteoarticular allograft) for pain control.

Q7. How likely is it that this operation will relieve my pain?

A7. This surgery is 80-90% sucessful in providing pain relief.

Q8. Will I need to take time off work following this operation?

A8. Patients are allowed to return to work in 2 weeks for a light duty desk job. Patients are not permitted to drive for 6 weeks if their right leg is affected.

pre-operative medial meniscus
meniscal allograft
post-operative medial meniscus