We need you! See something you could improve? Make an edit and help improve WikSM for everyone.

LCL Injury

From WikiSM
Jump to: navigation, search

Other Names

  • LCL Tear
  • Lateral Collateral Ligament Tear
  • Lateral Collateral Ligament Injury
  • LCL Sprain
  • Fibular ligament injury



  • Needs to be updated


  • Second least frequent of all ligamentous knee injuries at 7.9% (behind PCL)[1]
  • Isolated knee injuries represent less than 2% of knee injuries[2]


Lateral knee anatomy including the LCL[3]


  • Contact sports
    • Commonly medial blow to knee while in full extension
  • Noncontact[4]
    • Varus bending
    • Hyperextension
  • Motor vehicle crashes


Associated Conditions

Risk Factors

  • Female gender
  • Sports that require high velocity pivoting, jumping
  • Sports[6]
    • Tennis
    • Gymnastics
    • Wrestling
  • Orthopedic history
    • History of knee, ankle or hip injury[7]

Differential Diagnosis

Clinical Features

Examination of the patient in the figure-of-four position. This allows the examiner to directly palpate the LCL (a, arrow)[8]
  • History
    • Generally patients will report an acute, traumatic event
    • Sudden onset lateral knee pain, swelling and bruising
    • Instability with knee in extension
    • Trouble with stairs, cutting or pivoting activities
    • Rarely weakness, parasthesia or foot drop (increase risk in PLC injuries)
    • Sensation of walking "bow legged" due to increase laxity
  • Physical Exam: Physical Exam Knee
    • Tenderness to palpation of the distal lateral femur and/or fibular head
    • Ecchymosis, swelling and warmth may be present
    • Effusion is typically absent in isolated injuries (due to extra-articular nature of LCL)
  • Special Tests
    • Varus Stress Test (Knee): one hand on lateral knee, other on leg applying varus stress at 0° and 30°
    • Posterolateral corner tests
    • Important to perform thorough structural knee exam on MCL, ACL, PCL, posterolateral corner, etc

Small avulsion fracture of the styloid process of the proximal fibula, with a defect in the fibular head noted. This is known as the arcuate sign.[9]
Full-thickness rupture (grade III) of the distal lateral collateral ligament.[10]



  • Standard Radiographs Knee
    • Routine screening
    • Typically normal
  • May demonstrate
    • Fibular head fractures/avulsions (arcuate sign)
    • Tibial spine avulsions
    • Lateral tibial plateau (i.e., Segond fracture)
  • Alternative views
    • Varus stress view
    • Kneeling posterior stress radiographs
    • Measure shortest distance between most distal aspect of lateral femoral condyle, associated tibial plateu


  • Gold standard for evaluating LCL
  • Best seen in axial, coronal views
  • Accuracy (need citation)
    • Sensitivity: 90%
    • Specificity: 90%
  • Primary findings
    • Majority of tears off fibular insertion
    • Medial compartment bone bruising (T2-weighted)
    • Varying amounts of peri-ligamentous edema, intra-substance signal
    • Discontinuity of LCL fibers in higher grade tears


  • Acute findings
    • Edema
    • Loss of fiber continuity
    • Dynamic laxity
  • Chronic findings
    • Thickened
    • Hypoechoic


LCL Tear Classification

  • Grade 1 (Mild)
    • Localized lateral knee tenderness
    • No instability or mechanical symptoms are present.
    • 0 to 4 mm of laxity
  • Grade 2 (Partial Tear)
    • Severe localized lateral and posterolateral knee pain, swelling.
    • 5 to 10 mm of laxity with a fixed endpoint
  • Grade 3 (Complete Tear)
    • Pain and swelling vary in patients
    • Usually associated with PLC and other related injuries
    • >10mm of laxity with no firm end point

LCL Tear MRI Classification

  • Grade 1
    • Subcutaneous fluid surrounding the midsubstance of the ligament at one or both insertions
  • Grade 2
    • Partial tearing of ligament fibers at either the midsubstance or one of the insertions
    • Increased edema
  • Grade 3
    • Complete tearing of ligament fibers at either the midsubstance or one of the insertions
    • Increased edema



  • Indications[11]
    • Grade I, II
    • Stable varus stress test at 0°
  • Hinged Knee Brace
    • Should restrict varus motion
    • Discontinue after pain, sensation of instability resolve
  • Early Mobilization
  • Physical Therapy
    • Not always necessary in isolated injuries
    • May be needed in cases of prolonged immobilization


  • Indications
    • Grade III injuries (controversial)
    • Co-occuring injuries such as posterolateral corner, multiligament injuries
  • Technique
    • Repair
    • Reconstruction

Rehab and Return to Play


  • General
    • Limited immobilization with progression range of motion
    • functional rehabilitation
    • Emphasis on quadriceps, hamstring strengthening

Return to Play/ Work

  • Grade I and II
    • Can often return to sport in 6-8 weeks

Complications and Prognosis


  • Bushnell at al looked at NFL players with isolated grade III LCL injuries[2]
    • Nonsurgically managed injuries were as likely as those with surgically managed injuries to return to professional play
    • They did so more quickly
  • Krukhuag et al found surgically managed isolated grade III LCL injuries did better than nonsurgical counterparts[12]
  • Kannus found nonoperative management of isolated grade III injuries did not do as well as surgically managed patients[11]
    • Findings: severe or gross lateral laxity, insufficiency of the ACL, muscle weakness, and posttraumatic osteoarthritis
  • Studies show that the LCL does not heal as well as the MCL (need citation)


  • Common Peroneal Nerve Injury
    • Occurs in up to 44% of LCL/PLC combined injuries[4]
  • Persistent varus or hyperextension laxity
  • Stiffness
    • Tends to occur following prolonged immobilization with nonoperative management
  • Physeal arrest
    • Can be seen in skeletally immature patient with errant lateral condylar LCL fixation

See Also




  1. Swenson DM, Collins CL, Best TM, Flanigan DC, Fields SK, Comstock RD. Epidemiology of knee injuries among U.S. high school athletes, 2005/2006-2010/2011. Med Sci Sports Exerc. 2013 Mar;45(3):462-9.
  2. 2.0 2.1 Bushnell BD, Bitting SS, Crain JM, Boublik M, Schlegel TF: Treatment of magnetic resonance imaging-documented isolated grade III lateral collateral ligament injuries in National Football League athletes. Am J Sports Med 2010;38(1):86-91.19966106
  3. LaPrade RF, Spiridonov SI, Coobs BR, Ruckert PR, Griffith CJ (2010) Fibular collateral ligament anatomical reconstructions: a prospective outcomes study. Am J Sports Med 38(10):2005–2011
  4. 4.0 4.1 Chahla, Jorge, et al. "Posterolateral corner of the knee: current concepts." Archives of Bone and Joint Surgery 4.2 (2016): 97.
  5. Wilson WT, Deakin AH, Payne AP, Picard F, Wearing SC: Comparative analysis of the structural properties of the collateral ligaments of the human knee. J Orthop Sports Phys Ther 2012;42(4):345-351.22030378
  6. Grawe, Brian, et al. "Lateral collateral ligament injury about the knee: anatomy, evaluation, and management." JAAOS-Journal of the American Academy of Orthopaedic Surgeons 26.6 (2018): e120-e127.
  7. Hill OT, Bulathsinhala L, Scofield DE, Haley TF, Bernasek TL. Risk factors for soft tissue knee injuries in active duty U.S. Army soldiers, 2000-2005. Mil Med. 2013 Jun;178(6):676-82
  8. Jain, Rajat K. "Lateral collateral ligament injury." Common Pediatric Knee Injuries: Best Practices in Evaluation and Management (2021): 225-232.
  9. Case courtesy of Haytham Mohamed Assayed Bedier, Radiopaedia.org, rID: 56857
  10. Case courtesy of Henry Knipe, Radiopaedia.org, rID: 62164
  11. 11.0 11.1 Kannus, Pekka. "Nonoperative treatment of grade II and III sprains of the lateral ligament compartment of the knee." The American Journal of Sports Medicine 17.1 (1989): 83-88.
  12. Krukhaug Y, Mølster A, Rodt A, Strand T. Lateral ligament injuries of the knee. Knee Surg Sports Traumatol Arthrosc. 1998;6(1):21-5.
Created by:
John Kiel on 7 July 2019 05:43:53
Last edited:
16 March 2023 16:21:57