Management of Meniscal Extrusion After Meniscal Repair
Meniscal extrusion after meniscal repair should be addressed with centralization techniques during the repair procedure, as extrusion persists or worsens in over 96% of patients despite successful root repair and significantly impairs meniscal function. 1
Understanding the Problem
Meniscal extrusion is defined as displacement of the meniscal margin by at least 3 mm beyond the tibial margin. 2 This represents a critical failure of meniscal biomechanics because:
- Extrusion impairs the meniscus's ability to absorb hoop stress, leading to altered knee kinematics and aberrant forces 1, 3
- The primary cause is failure of the meniscotibial ligament complex, not just the meniscal root tear itself 3, 4
- Extrusion is a major risk factor for osteoarthritis progression and poorer patient-reported outcomes 1, 3
Surgical Management Algorithm
Primary Surgical Approach
When performing meniscal root repair, add a centralization suture to the standard transtibial repair technique. 1 The evidence is compelling:
- A 2025 randomized controlled trial demonstrated that adding centralization sutures to 2-tunnel transtibial root repair significantly reduced postoperative extrusion increase (21.4% increase versus 59.8% increase without centralization, P = 0.016) 1
- Without centralization, extrusion increased in 96.2% of patients at 6 months despite intact repair constructs 1
- Isolated root repair is insufficient - the meniscotibial ligaments must be addressed 3, 4
Specific Centralization Technique
Repair the meniscotibial ligament complex using all-inside meniscal repair devices or knotless suture anchors (typically 3 anchors) to reduce the meniscus to its anatomic footprint. 3, 4 The biomechanical rationale:
- Meniscotibial ligament lesions alone cause significant extrusion (1.5 mm baseline to 3.4 mm after lesion creation, P < 0.001) 4
- Repair of these ligaments reduces extrusion by approximately 48% clinically 4
- The simplified technique uses all-inside devices through a transtibial tunnel, avoiding the technical challenges of accessory portals 3
When Extrusion is Already Present
If extrusion is identified after a previous meniscal repair without centralization, perform arthroscopic direct meniscal extrusion reduction with meniscotibial ligament repair. 2, 4 This involves:
- Direct arthroscopic reduction of the extruded meniscus back to the tibial margin 2
- Repair of the meniscotibial ligament complex to maintain reduction 4
- Use of 3 knotless suture anchors or all-inside devices for fixation 3, 4
Critical Pitfalls to Avoid
Do not assume that successful root repair alone will prevent extrusion - even with intact repair constructs on MRI, extrusion worsens in nearly all patients without centralization 1
Do not ignore the meniscotibial ligaments - these structures are the primary stabilizers preventing extrusion, and isolated root repair does not address this pathology 3, 4
Do not delay addressing extrusion - persistent extrusion leads to progressive osteoarthritis and compromised meniscal function 1, 3
Expected Outcomes
With centralization techniques added to root repair:
- Extrusion still increases by approximately 21% at 6 months, but this is significantly better than the 60% increase without centralization 1
- Clinical reduction of approximately 48% in absolute extrusion can be achieved with meniscotibial ligament repair 4
- Complete elimination of extrusion is rare - the goal is minimizing progression rather than achieving perfect anatomic restoration 1, 4
Context Within Broader Meniscal Management
This surgical approach applies specifically to patients undergoing meniscal repair. Meniscal repair is superior to partial meniscectomy with better functional outcomes and less severe degenerative changes over time. 5, 6 However, for degenerative tears in patients over 35, conservative management with structured physical therapy remains first-line treatment, and arthroscopic surgery should not be the initial approach. 7, 5