Meniscal Repair Techniques

Courtesy: Prof Wolf Petersen, Berlin, Germany

 

Understanding Meniscus Anatomy and Function

• Medial and lateral meniscus serve as a movable joint surface.
• Contributes to load transmission and joint stabilization.
• Meniscal loss leads to joint overload, resulting in osteoarthritis.
• Importance of meniscus preservation to prevent cartilage damage and osteoarthritis.

Importance of Meniscus Repair in ACL Injuries

• ACL injuries often involve associated meniscal, cartilage, and ligament damage.
• Untreated meniscal injuries increase the risk of post-traumatic osteoarthritis.
• Meniscus repair during ACL reconstruction enhances long-term joint stability.

Meniscus Healing Potential and Repair Criteria

• Healing potential depends on vascular supply:
  • Red Zone: Good blood supply, higher healing potential.
  • White Zone: Avascular, poor healing potential.
• Favorable repair criteria:
  • Tears in vascular zones.
  • Longitudinal tears.
  • Acute lesions.
  • Younger age.
• Contraindications:
  • Tears in the white zone.
  • Chronic lesions.
  • Poor tissue quality.
  • Older patient age.

Meniscus Repair Techniques

1. Outside-In Technique

• Cost-effective and biomechanically stable.
• Sutures passed through puncture needles and tied at the joint capsule.

1. Inside-Out Technique

• Commonly used in the United States.
• Requires specialized instruments and caution to avoid saphenous nerve injury.

1. All-Inside Technique

• Utilizes suture anchors and self-locking knots.
• Minimizes nerve injury risk.
• Preferred for posterior meniscal tears.

Hybrid Repair Approach

• Combination of different techniques for various meniscal zones:
  • Posterior part: All-inside technique.

  • Intermediate part: Inside-out or outside-in technique.

  • Anterior part: Outside-in technique.

Long-Term Outcomes and Failure Rates

• 22% failure rate after 10 years.
• Bucket-handle tears show the highest failure rates (up to 50%).
• Techniques to improve healing:
  • Microfracture in the notch.
  • Biological augmentation with growth factors.
• Combined ACL reconstruction reduces failure rates due to better stability and biological factors.

Special Considerations for Ramp and Root Lesions

• Ramp Lesions:
  • Tears in the menisco-capsular and menisco-tibial ligaments.
  • Often missed on MRI; requires arthroscopic probing through the posteromedial portal.
  • Stable ramp lesions: Conservative management.
  • Unstable ramp lesions: Suture hook repair preferred over all-inside anchor repair.
• Meniscal Root Tears:
  • Avulsion or radial tear within 5 mm of the insertion.
  • Medial root tears: Degenerative, common in older patients with varus deformity.
  • Lateral root tears: Traumatic, associated with ACL injuries.
• Diagnosis aided by MRI signs:
  • Ghost sign, meniscal extrusion, and subchondral bone edema.
• Meniscal Root Repair:
  • Trans-tibial pullout technique using a cortical button or interference screw.
  • Centralization may be required to reduce extrusion.
  • Combined high tibial osteotomy (HTO) and root repair recommended for patients with varus deformity and minimal osteoarthritis.

Rehabilitation Protocols

• Rehabilitation varies based on tear type and repair technique:
  • Smaller tears (<20 mm): Gradual weight-bearing and range of motion.
  • Larger or complex tears: Restricted weight-bearing to optimize healing.
• For ACL reconstruction with longitudinal tears >20 mm:
  • 4 weeks partial weight-bearing, ROM restricted to 0–60°.
  • Additional 2 weeks, ROM increased to 0–90°.
• Isolated bucket handle tears:
  • 6 weeks partial weight-bearing.
  • 4 weeks ROM 0–60° and 2 weeks up to 90°.
• Medial meniscus root or radial tears:
  • 6 weeks of non-weightbearing with ROM restrictions.

Video Demonstration of Meniscus Repair

• Demonstration of bucket-handle tear repair after ACL reconstruction.
• Steps included:
  • Debridement and preparation of the tear.
  • Microfracture device for peripheral abrasion.
  • All-inside fiber stitch technique for anchoring.
  • Inside-out technique for intermediate tears.
  • Outside-in technique for anterior tears using a vertical suture configuration.

Challenges and Complications

• Persistent pain may result from cystic formation around implants.
• Rare cases may require revision to remove prominent implants or address nerve entrapment.
• Case of CRPS due to saphenous nerve injury highlighted the importance of visualizing the needle path during repairs.

Discussion and Q&A Session

• Addressed visualization challenges of the posterior horn of the medial meniscus in ACL-deficient knees:
  • Suggested slight knee flexion (around 30°) and applying valgus stress.
  • Cautioned against MCL pie-crusting due to concerns of increasing medial instability.
• Meniscal extrusion discussed as a consequence of:
  • Varus deformity.
  • Increased load or obesity.
• Highlighted that meniscal extrusion becomes static and irreversible without intervention.

Conclusion and Future Initiatives

• Emphasis on meniscus preservation to prevent long-term complications and maintain knee stability.
• Professor Petersen expressed enthusiasm about future collaborations and educational initiatives.