A 46-year-old woman sustained a complete posterior dislocation of the right knee two days ago with intact neurovascular structures; how should the torn knee ligaments be managed?

Management of Multiligament Knee Injury Following Complete Posterior Knee Dislocation

This patient requires urgent surgical reconstruction of all torn ligaments, ideally performed within 2-3 weeks once soft tissue swelling subsides, to prevent long-term instability, progressive meniscal and cartilage damage, and poor functional outcomes.

Immediate Management (Days 0-14)

• Maintain knee reduction and immobilization in a hinged knee brace locked in extension or slight flexion (0-20 degrees) to protect neurovascular structures and prevent redislocation 1
• Serial neurovascular examinations are mandatory even with initially intact pulses, as delayed vascular complications can occur 1, 2
• Aspiration of tense hemarthrosis may be considered for patient comfort 3
• Advanced imaging with MRI should be obtained once the patient is stable to fully characterize all ligamentous injuries, meniscal tears, and chondral damage 4, 5

Surgical Timing and Approach

Early surgical reconstruction (within 2-3 weeks) is strongly recommended once acute swelling resolves but before 3 months post-injury, as the risk of additional cartilage and meniscal injury increases significantly after this timeframe 3, 2. Posterior knee dislocations typically involve ACL, PCL, and posterolateral corner structures, often with medial or lateral collateral ligament involvement 2, 5.

Key Surgical Principles:

• Single-stage anatomic reconstruction of all injured ligaments is preferred over staged procedures or isolated repairs, which have higher failure rates 2, 5
• Autograft should be strongly favored over allograft in this 46-year-old active patient to reduce graft failure rates 3
• Reconstruction rather than repair alone is recommended for cruciate ligaments and posterolateral corner structures due to superior outcomes 2
• MCL injuries can often be treated non-operatively or with repair/augmentation depending on severity, as non-surgical MCL treatment yields good outcomes even with combined ACL injuries 3

Graft Selection Strategy:

• For ACL reconstruction: Consider bone-patellar tendon-bone (BTB) autograft to reduce graft failure risk, or hamstring autograft if anterior knee pain is a concern 3
• For PCL reconstruction: Double-bundle anatomic reconstruction using autograft (typically hamstring or quadriceps tendon) 6, 5
• For posterolateral corner: Anatomic reconstruction using autograft or allograft depending on available tissue 2, 5

Critical Technical Considerations

Graft sequencing matters significantly to prevent tunnel convergence and optimize biomechanics 5:

• PCL tunnels should be drilled first
• ACL tunnels second
• Collateral and corner reconstructions last
• Tensioning should occur with knee at 20-30 degrees flexion for PCL, 0-20 degrees for ACL 5

Common Pitfalls to Avoid

• Delaying surgery beyond 3 months dramatically increases risk of irreversible meniscal and cartilage damage 3, 2
• Attempting repair alone without reconstruction leads to unacceptably high failure rates in multiligament injuries 2, 5
• Missing associated injuries such as meniscal tears, chondral defects, or occult fractures that require concurrent treatment 4, 5
• Inadequate postoperative protection - functional bracing is not routinely beneficial after isolated ACL reconstruction, but is essential during early rehabilitation of multiligament reconstructions 3, 5

Rehabilitation Timeline

• Immediate postoperative motion should begin on day 1 with modern anatomic reconstruction techniques using appropriate graft fixation 5
• Protected weight-bearing for 6-12 weeks depending on specific ligaments reconstructed 5
• Return to full activity typically requires 9-12 months with functional testing (hop tests) used as one factor in clearance decisions 3, 5

Expected Outcomes

Even with optimal surgical management, complete posterior knee dislocations carry significant risk for:

• Post-traumatic arthritis development 7, 2
• Persistent mild instability or range of motion limitations 2, 5
• Inability to return to pre-injury activity level in some patients 7, 4

Early specialist referral to a surgeon experienced in multiligament knee reconstruction is essential given the technical complexity and high complication rates when these injuries are mismanaged 7, 2.