What is the appropriate treatment for a knee dislocation that occurred three weeks ago?

Treatment for Post-Knee Dislocation at 3 Weeks

At 3 weeks post-knee dislocation, you should proceed urgently with comprehensive MRI evaluation followed by surgical reconstruction of all injured ligamentous structures, as this represents the tail end of the acute treatment window where outcomes remain superior to delayed reconstruction.

Immediate Diagnostic Workup

You are at a critical juncture—3 weeks post-injury sits at the boundary between acute (optimal) and chronic (suboptimal) management. MRI without IV contrast is the essential next step to fully characterize all ligamentous, meniscal, cartilage, and bone injuries 1. The imaging will guide your surgical planning and should be obtained immediately if not already done.

Key structures to assess on MRI:

• ACL and PCL integrity
• Medial and lateral collateral ligament complexes
• Posterolateral corner structures
• Anterolateral ligament
• Meniscal tears
• Bone marrow contusions and occult fractures
• Cartilage injuries

Surgical Timing: Act Now

The evidence strongly favors acute reconstruction (within 3 weeks) over delayed treatment. You are still within this window, but barely:

• **Acute reconstruction (<3 weeks) produces significantly better outcomes** than chronic reconstruction (>3 weeks), with higher Lysholm scores (91 vs 80 points), better Knee Outcome Survey scores (91 vs 84 for ADL, 89 vs 69 for sports), and more predictable restoration of knee stability 2.

• Another study confirms this, showing mean Lysholm scores of 87 in acute cases versus 75 in delayed cases, with better anterior tibial translation control when treated within 2 weeks 3.

• For ACL injuries specifically, reconstruction should occur as soon as possible, as risk of additional cartilage and meniscal injury increases within 3 months 4.

Surgical Approach

Perform anatomical repair and/or reconstruction of ALL injured ligamentous structures in a single-stage procedure 2, 5:

Graft Selection

• Use autograft over allograft, particularly in young and active patients, to reduce graft failure rates 4
• For ACL reconstruction: Consider bone-patellar tendon-bone (BTB) to reduce graft failure risk, or hamstring to reduce anterior knee/kneeling pain 4
• If using hamstring autograft, consider adding anterolateral ligament reconstruction or lateral extra-articular tenodesis to reduce graft failure 4
• Fresh-frozen allograft can supplement autograft tissue as needed 2

Reconstruction Strategy

• Reconstruct ACL and PCL
• Address medial structures: In acute cases, direct repair of the posterior medial corner (PMC) is often possible; at 3 weeks you may still achieve this 5
• Address lateral structures: Reconstruct posterolateral corner if injured
• Repair or reconstruct collateral ligaments as indicated

Critical Pitfalls to Avoid

Do not delay further. Every week beyond 3 weeks worsens your outcomes:

• Chronic reconstruction (>6 months) shows substantially worse functional scores and less predictable stability restoration 2, 3
• The "dimple sign" (irreducible dislocation) requires immediate surgical reduction—ensure the knee is fully reduced 5
• Missing posterolateral corner injuries leads to considerable morbidity; these occur in ~20% of ACL ruptures 1

Vascular and Neurovascular Considerations

Even at 3 weeks, confirm:

• No delayed vascular compromise (occurs in ~30% of posterior dislocations) 1
• Document neurological status (peroneal and tibial nerve function) 1
• If any concern exists, obtain CTA of the lower extremity 1

Expected Outcomes

With appropriate acute surgical management at this timepoint:

• Average range of motion: expect ~12° loss of flexion, minimal extension loss 2
• 4-5 patients may require manipulation for loss of flexion 2
• Most patients return to daily activities successfully, though return to high-demand sports is less predictable 2
• Watch for heterotopic ossification (occurs in ~44% of cases) 6

Postoperative Rehabilitation

After reconstruction, functional evaluation including hop testing should guide return to sport decisions, though specific timing remains controversial 4. The key is achieving adequate stability and strength before clearance.

Bottom line: Schedule surgery within days, not weeks. You are at the outer edge of the acute window where outcomes remain favorable.