Lateral Collateral Ligament Tear

Ovid: 5-Minute Sports Medicine Consult, The

Lateral Collateral Ligament Tear
Brent S. E. Rich
Mitchell Pratte
  • Partial or complete sprain of the lateral collateral ligament (LCL) owing to an acute force, usually from a medial direction
  • Consists of a cordlike fiber bundle that runs from the lateral femoral condyle to the lateral aspect of the fibular head about 1 cm anterior to the apex: discrete extracapsular structure.
  • Primary restraint to varus stress with the knee in extension
  • Isometric between 0 and 70 degrees of flexion, followed by slackening trend with deeper flexion
  • Least commonly injured knee ligament; isolated injuries are rare.
  • Infrequent site of overuse injury or rupture
  • Wrestling is the most likely associated sport.
  • May be associated with injury to other ligaments [anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL)] or structures of the posterolateral corner (popliteus tendon, biceps femoris, iliotibial band, popliteofibular ligament) and peroneal nerve injuries
Risk Factors
  • Unclear if previous LCL injuries predispose to recurrent injury
  • Varus knee, otherwise normal, does not seem to be predisposed to LCL injury.
  • PCL deficiency may increase risk of LCL injury.
  • Contact or noncontact varus stress to partially flexed knee in internal tibial rotation from direct force or, more rarely, distal indirect stress (eg, stepping into a hole) with fixed foot
  • Acute lateral knee pain
  • Many hear/feel an associated “pop.”
  • LCL is extraarticular; mild to moderate swelling is associated with isolated injury.
  • Mild disability with low-grade injury; difficult weight bearing with high-grade injury/associated injuries owing to pain and instability
  • Instability with high-grade or moderate injury
  • Check for possible peroneal nerve symptoms.
Physical Exam
  • Signs and symptoms:
    • Acute lateral knee pain associated with a mechanism of varus stress with knee in flexion of 25–30 degrees
    • Patient may feel or hear a “pop” at time of injury.
    • Swelling variable, effusion not common with low-grade injuries; associated ligamentous injuries may cause significant effusion.
    • Instability symptoms in high-grade injury or with associated underlying varus knee
    • Possible peroneal nerve symptoms
  • Physical examination:
    • Local swelling over ligament
    • Tender to palpation over ligament
    • Readily palpated in “figure-of-4 position”: Normally a pencil-like structure but less distinct with partial tears (grade II) or complete tears (grade III)
    • Varus stress testing: Grade I sprain, no increased laxity; grade II sprain, increase in laxity with semifirm endpoint at 25–30 degrees of flexion isolates the LCL; grade III sprain, increase in laxity with soft or no endpoint compared with the uninjured knee indicates injury.
    • Careful assessment of ACL (Lachman test) and PCL (posterior drawer test), posterolateral structures (external rotation recurvatum test, external rotation roll-out test at 90 and 30 degrees, posterolateral drawer sign), and pivot shift if possible. Grade I injuries may be confused with lateral meniscal tears.
    • Peroneal nerve sensory and motor function should be checked as well.
Diagnostic Tests & Interpretation
  • Plain films to rule out occult fracture of tibial plateau, lateral femoral condyle, or fibular head on all patients
  • MRI to better assess integrity of LCL and associated knee structures (ACL, PCL, lateral meniscus, popliteus tendon, posterolateral corner)


Differential Diagnosis
  • Proximal fibula avulsion fracture
  • Biceps femoris strain
  • Iliotibial band strain
  • Popliteus strain/tear
  • Associated anterior or posterior cruciate injury
  • Lateral meniscus tear
  • Lateral compartment chondral/osteochondral injury
  • Tibial plateau fracture
  • Associated loose body
  • Peroneal nerve injury
Ongoing Care
Follow-Up Recommendations
  • Referral to orthopedic surgery for any fracture, associated ligament injury, complex meniscal tear, or grade III injury that is not amenable to the initial 2–4 wks of rehabilitation
  • Associated neurovascular injuries should be considered emergent, and appropriate surgical/radiographic consultations should be initiated and performed on the same day.
Additional Reading
Kozanek M, et al. Posterolateral structures of the knee in posterior cruciate ligament deficiency. Am J Sports Med. 2009;3.
Van de Velde S, et al. The effect of anterior cruciate ligament deficiency on the in vivo elongation of the medial collateral and lateral collateral ligament. Am J Sports Med. 2007;35.
Victor J, et al. How isometric are the medial patellofemoral, superficial medial collateral, and lateral collateral ligaments of the knee? Am J Sports Med. 2009;37.
Wheeless' Textbook of Orthopaedics, Duke University, 2009,
844.0 Sprain of lateral collateral ligament of knee

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