Symptomatic Meniscal Deficiency: Primarily for patients younger than 50 with pain localized to the compartment where the meniscus is missing, but without advanced osteoarthritis (OA).

Post-Meniscectomy Syndrome: For those experiencing pain, swelling, and instability after a total or subtotal meniscectomy (removal of the meniscus).

Concomitant Procedures: Often performed alongside correction of knee alignment, ligament reconstruction, or articular cartilage repair to ensure optimal outcomes.

Surgical Methods:

• Bone Plug vs. Soft Tissue Fixation: Both techniques are used, with bone plug fixation showing potentially better biomechanical outcomes, though soft tissue fixation is also effective with fewer complications in some studies.

• Arthroscopic vs. Open Surgery: There's a trend towards arthroscopic techniques due to less invasiveness and potentially quicker recovery.

Graft Preparation:

• Fresh-Frozen vs. Cryopreserved: Fresh-frozen allografts are more commonly used for their biomechanical properties similar to native meniscus, although cryopreserved options are also viable, with high cell death noted.

• Sizing: Accurate sizing is critical for success, often using radiographic or MRI measurements for matching.

How long will it last?

• Approximately 73.5% last 10 years and 60.3% 15 years, suggesting a decrease over time but still providing significant symptom relief for many patients.

• Lateral meniscus transplants generally have higher survival rates compared to medial ones.

Clinical Benefits:

• Significant improvement in pain scores and knee function, with about 90% of patients reporting they would undergo the procedure again.

• Possible chondroprotective effect (strategies and substances that protect and smooth cartilage), although long-term evidence on delaying OA is still debated.

Complications:

• Reoperation rates are around 32%, with the most common issue being meniscal allograft tears.

• Other complications include graft extrusion, failure, and progression of joint pathology.

Patient Selection: Critical for success; patients with advanced arthritis or significant malalignment might not benefit as much.

Graft Availability: The need for size and compartment-specific grafts can sometimes delay or complicate the procedure.

Long-term Efficacy: While short to medium-term outcomes are promising, the long-term chondroprotective effect remains under scrutiny.

Cost and Accessibility: MAT is costly and not universally available, leading to disparities in treatment access globally.

Research Focus: Ongoing studies aim to better understand the long-term effects on OA progression, improve graft survival, and refine surgical techniques.

Biological Augmentation: Techniques like using PRP or stem cells during surgery to enhance healing and integration are being explored.

Segmental Transplants: For cases where only part of the meniscus is damaged, segmental transplants are being investigated as an option to preserve more native tissue.