What are the best allograft sources for lateral collateral ligament reconstruction in a 46-year-old woman?

Best Allograft Sources for Lateral Collateral Ligament Reconstruction

For lateral collateral ligament (LCL) reconstruction in a 46-year-old woman, bone-patellar tendon-bone (BTB) allograft is the preferred choice, though hamstring tendon allograft represents an equivalent alternative with similar clinical outcomes.

Evidence-Based Graft Selection

Primary Recommendation: Bone-Patellar Tendon-Bone Allograft

The BTB allograft offers several advantages for LCL reconstruction:

• Bone-to-bone healing: The bone blocks allow for interference screw fixation in both the femoral and fibular tunnels, providing secure fixation and promoting biological incorporation 1
• Structural integrity: The patellar tendon provides robust tensile strength appropriate for the biomechanical demands of the LCL
• Proven track record: Historical data demonstrates successful correction of varus instability and external rotation laxity with BTB allograft 1

Alternative Option: Hamstring Tendon Allograft

Hamstring allografts (particularly semitendinosus) represent an equally valid choice:

• Equivalent outcomes: A 2021 comparative study showed no significant differences in varus stress laxity at 6 months or clinical outcomes at ≥2 years between hamstring autografts and allografts for fibular collateral ligament reconstruction 2
• No graft failures: Zero LCL reconstruction failures were observed in either autograft or allograft cohorts 2
• Similar stability: No significant side-to-side differences in lateral compartment gapping on varus stress radiographs (allograft 0.49 mm vs autograft 0.15 mm, P=0.22) 2

Achilles Tendon Allograft for Complex Cases

When LCL reconstruction is combined with ACL revision or anterolateral ligament reconstruction:

• Single Achilles tendon allograft can be split after ACL fixation to reconstruct both the LCL and anterolateral structures 3
• This approach is particularly useful in multi-ligament reconstructions where graft economy is important

Clinical Context for This Patient

At age 46, this patient falls into a demographic where:

• Autograft vs allograft considerations: While the 2023 AAOS guidelines strongly recommend autograft over allograft for ACL reconstruction in young/active patients 4, these recommendations specifically address ACL injuries, not LCL reconstruction
• Donor site morbidity avoidance: Allograft eliminates harvest site complications, which is particularly relevant in middle-aged patients 5
• Multi-ligament context: If concomitant ACL reconstruction is needed, allograft for LCL preserves autograft options for the ACL

Technical Considerations

Fixation Strategy

• Place femoral tunnel at the isometric point on the lateral femoral condyle
• Place fibular tunnel in the fibular head
• Use interference screw fixation for BTB grafts 1

Expected Outcomes

Based on available evidence:

• Correction of excessive external rotation at 30° flexion in >90% of cases
• Reduction of varus laxity to 0-1+ in most patients
• Average Tegner activity scores of 4-5, with majority returning to preinjury or one level below activity 1

Critical Pitfall to Avoid

Do not overlook concomitant posterolateral corner injuries. LCL injuries rarely occur in isolation—assess for popliteus tendon, popliteofibular ligament, and biceps femoris involvement. Failure to address the entire posterolateral complex leads to persistent instability and graft failure.

Summary of Allograft Options (Ranked)

1. Bone-patellar tendon-bone allograft (preferred for isolated LCL)
2. Hamstring tendon allograft (equivalent alternative)
3. Achilles tendon allograft (best for multi-ligament reconstructions requiring graft splitting)

The choice between BTB and hamstring allograft can be based on surgeon preference and technical factors, as both demonstrate equivalent radiographic stability and patient-reported outcomes at short to medium-term follow-up 2, 5.