Lateral Collateral Ligament Tear

synonyms: fibular collateral ligament tear, lateral collateral ligament tear, LCL tear

LCL ICD-9

• 844.0 (Sprain and strains of knee and leg; lateral collateral ligament of knee.

LCL Etiology / Epidemiology / Natural History

• Isolated injury is uncommon.

LCL Anatomy

• Origin: Lateral femoral epicondyle posterior and superior to the insertion of the poplitieus.
• Insertion: Fibular head
• Function: Primary restraint to varus stress of the knee. Resist tibial external rotation.
• Tight in extension, lax in flexion.

LCL Clinical Evaluation

• Lateral knee tenderness.
• Varus laxity with the knee in 30° of flexion as compared to normal side indicates isolated LCL tear. Laxity in full extension is indicative of a more severe injury involving multiple ligaments and potentially both cruciates.
• Isolated injury is uncommon.

LCL Xray / Diagnositc Tests

• A/P, lateral knee xrays: generally normal.
• MRI: Grade 1 = edema (increased T2 signal) superficial to intact ligament. Grade 2 = edema within the substance of the ligament with some intact fibers. Grade 3 = complete ligament disruption (high signal traversing ligament on T2 images. (Schweitzer ME, Radiology, 1995;22:411)

LCL Classification / Treatment

• Acute Isolated LCL injury:
  Grade I injury (0 to 5 mm of medial opening). Treatment: Hinged knee brace with early motion and functional rehabilitation. Typically brace opened from 15° to 60° for first 4weeks. Then open 0°-120°for 4 weeks for a total of 8 weeks of bracing.
  Grade II injury (6 to 10 mm of medial opening). Treatment: Hinged knee brace with early motion and functional rehabilitation. Typically brace opened from 15° to 60° for first 4weeks. Then open 0°-120°for 4 weeks for a total of 8 weeks of bracing.
  Grade III injury (11 to 15 mm of medial opening). Treatment: LCL repair, ensure other ligments are not injured as isolated Grade III injuries are uncommon.
• Chronic LCL injury which has failed non-operative treatment.
  Treatment: LCL repair.
• Acute Multiple ligament knee injury / Knee Dislocation
  Treatment: LCL repair. + cruciate ligmanet repair + posterolateral reconstruction.
• Chronic PLC instability with varus knee alignment: Treatment = valgus-producing HTO. Soft tissue reconstructions will eventually stretch out and fail. (Naudie DD, AJSM 2004;32:60).

LCL Associated Injuries / Differential Diagnosis

• Posterolateral corner
• PCL Tear
• Meniscus tear
• MCL tear
• Chondral injury
• ACL tear
• Patellar Dislocation
• Popliteus avulsion
• Knee Dislocation

LCL Complications

• Instability
• Stiffness:
• Painful hardware:
• Infection:
• Arthrofibrosis: rare
• NVI (peroeal nerve): rare
• Complex Regional Pain Syndrome: rare
• Hemarthrosis

LCL Follow-up Care

LCL Review References

• Larson RV, in Delee and Drez Orthopedic Sports Medicine, 2nd ed, 2003
• Indelicato PA, JAAOS 1995;3:9
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