AUTHOR AND EDITOR INFORMATION

Section 1 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

INTRODUCTION

Section 2 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Background

Lateral collateral ligament (LCL) injuries occur from a varus force to the knee (ie, a force directed at the medial side of the knee or leg). These injuries are much less common than medial collateral ligament (MCL) injuries because the opposite leg usually guards against direct blows to the medial side of the knee. However, LCL injuries can occur in situations in which trauma occurs as the leg is extended in front of the body, such as when attempting to gain control of the ball from another player in soccer or rugby (eg, tackling). (See also the eMedicine article Medial Collateral and Lateral Collateral Ligament Injury.)

Functional Anatomy

The LCL is a round ligament that lies beneath the tendon of the biceps femoris muscle and runs from the lateral epicondyle, anterior to the origin of the gastrocnemius muscle, to the fibular head. The LCL lies just posterior to mid-axial point of the knee and is the primary restraint to varus stress in the knee.

Sport-Specific Biomechanics

The LCL is taut when the knee is extended, and it is loose when flexed more than 30°.¹ Unlike the MCL, the LCL is not attached to the lateral meniscus but is separated from it by a small fat pad. The LCL is the primary restraint to varus rotation (coronal plane force) from 0-30° of knee flexion and secondarily resists internal rotation of the tibia.

CLINICAL

Section 3 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

History

• The mechanism of injury is the most important component of the patient history to determine the possible injured structures. Direct contact to the anteromedial aspect of the tibia is the most likely cause of injury to the LCL.
• Ascertain whether the patient noted any effusion within a few hours following the incident. One should not expect a significant joint effusion unless there also is a cruciate ligament or meniscal tear. It is also important to determine whether the individual felt or heard a pop in the knee, as this may suggest a concomitant injury. (See also the eMedicine articles Anterior Cruciate Ligament Injury, Posterior Cruciate Ligament Injury, and Meniscus Injuries)
• Inquire about previous knee symptoms, injuries, or surgeries.
• Discuss and obtain the patient's age, occupation, recreational activities, lifestyle, and interests to help determine the proper course of treatment.
• A more concerning injury is one that involves the posterior lateral complex. The most important structures in this complex include the iliotibial tract, long and short head of the biceps femoris muscle, fibular collateral ligament, posterior arcuate ligaments, and the posterior capsule. The peroneal nerve can also be injured because of its proximity to the biceps tendon; this type of injury requires extensive surgical repair because of the complex structures involved. The surgery should be individualized to each patient and his or her specific injuries. (See also the eMedicine article Iliotibial Band Syndrome.)

Physical

• Examine the injured extremity.
• • Inspect the leg for gross abnormalities, skin abrasions, and other signs.
  • Inspect and palpate the suprapatellar pouch for effusion.
  • Palpate for joint-line tenderness.
  • Perform special tests for LCL stability: Varus stress occurs at 0° and 30° of flexion. The LCL is isolated at 30°; testing at 0° also evaluates the posterolateral corner structures and cruciate ligaments.
  • Physical examination clues of posterolateral injury include footdrop, peroneal nerve injury, tenderness in the posterolateral corner, and pain with posterior-internal rotation of the tibia. (See also the eMedicine article Foot Drop.) 
  • Assess the cruciate ligaments and the menisci.
  • Evaluate for effusion.
  • Examine the uninvolved extremity. Compare the alignment, motion, swelling, and ligamentous stability of the affected limb with the injured extremity.
• Grade the degree of the LCL injury according to the following^{2, 3}:
• • Grade 1 – Interstitial injury without laxity is present, but there is pain with varus stress; only microscopic tearing has occurred.
  • Grade 2 – A 5-10 mm of joint-space opening with a distinct end point is noted; partial macroscopic tearing has occurred.
  • Grade 3 – Complete tearing (>10 mm joint-space opening) has occurred; complete macroscopic tearing is noted. 

Causes

• LCL injury is caused by a direct blow to the medial aspect of the knee or the anterior medial tibia with the foot planted and the knee in various degrees of flexion.
• An LCL injury should not be confused with other overuse lateral knee injuries (eg, iliotibial band syndrome, biceps femoris tendinitis). (See also the eMedicine article Iliotibial Band Syndrome.)

DIFFERENTIALS

Section 4 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Other Problems to Be Considered

Meniscal tear
Osteochondral fracture
Biceps femoris tendinitis

WORKUP

Section 5 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Imaging Studies

• Plain films should be obtained to rule out fractures or dislocations following acute traumatic injuries and to rule out degenerative joint disease with chronic injuries. If a small fragment of the distal femur or proximal tibia (Segond sign) is detected on the plain films, this should alert the physician of a concomitant anterior cruciate ligament tear.
• A magnetic resonance imaging (MRI) study is the examination of choice for diagnosing ligament and meniscal tears.
• If multiple ligaments are torn (3 or 4), an arteriogram may be performed to evaluate for a popliteal artery injury.
• Electromyogram (EMG) and nerve conduction velocity (NCV) tests may assess for peroneal nerve injury. If acute injury is suspected, referral to an orthopedist for nerve exploration may be helpful before ordering EMG and NCV tests.

TREATMENT

Section 6 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Acute Phase

Rehabilitation Program

Physical Therapy

For grade I and II LCL injuries, the suggested treatment includes rest, ice, compression, elevation (RICE), and non–weight-bearing restriction with the use of crutches. Hinged bracing may also be helpful. Grade III injuries, those usually involving a tear of posterolateral capsular complex, are best treated with surgical intervention.⁴ A return to full-weight-bearing gait should be gradual over the course of 4 weeks.

Surgical Intervention

Grade III tears usually involve a tear in the posterolateral capsular complex and are best treated with surgical intervention.⁴

Recovery Phase

Rehabilitation Program

Physical Therapy

Physical therapy consists of early range-of-motion (ROM) exercises, particularly cycling and quadriceps-strengthening exercises.

MEDICATION

Section 7 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Short-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) is acceptable for treating the symptoms of LCL injury.

Drug Category: Nonsteroidal anti-inflammatory agents (NSAIDs)

Although most NSAIDs are used primarily for their anti-inflammatory effects, they are effective analgesics and are useful for the relief of mild to moderate pain. Any prescription-strength NSAID can be effective. For patients who cannot tolerate the early-generation NSAIDs because of gastrointestinal (GI) intolerance, they may benefit from cyclooxygenase-2 (COX-2) inhibitors (eg, celecoxib [Celebrex], Pfizer Inc, New York, NY).

Drug Category: COX-2 Inhibitors

Although increased cost can be a negative factor, the incidence of costly and potentially fatal GI bleeding is clearly less with COX-2 inhibitors than with traditional NSAIDs. Ongoing analysis of the cost avoidance of GI bleeds further defines the populations that will find COX-2 inhibitors the most beneficial.

FOLLOW-UP

Section 8 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Return to Play

The goal of rehabilitation is for the athlete to return to his or her sport as soon as is safely possible. The time frame for return to play is dependent on the severity of the LCL injury and the type of treatment that is rendered. All individuals with LCL injuries are recommended to undergo physical therapy to properly rehabilitate the knee before they resume sporting activities.

After completing the initial recovery of ROM, the athlete needs to regain strength and functional rehabilitation, including proprioception, sport-specific activity, and some type of dynamic running program.

Functional testing (eg, one-legged balance, jumping, running, cutting) should be completed to evaluate the overall condition of the knee. Athletes should be pain free with functional activities and regain full strength and ROM before they return to sports.

Complications

• Chronic pain
• Weakness
• Instability
• Peroneal nerve injury

Prevention

Most cases of LCL injuries are not preventable. However, maintaining good flexibility and strength in the leg muscles with an adequate quadriceps-hamstring strength ratio may lower one's chances for a knee injury.

Prognosis

With proper treatment and rehabilitation, the prognosis for LCL injuries is good to excellent.

Education

For excellent patient education resources, visit eMedicine's Foot, Ankle, Knee, and Hip Center and Sports Injury Center. Also, see eMedicine's patient education article Knee Injury.

REFERENCES

Section 9 of 9

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

1. LaPrade RF, Terry GC. Injuries to the posterolateral aspect of the knee. Association of anatomic injury patterns with clinical instability. Am J Sports Med. Jul-Aug 1997;25(4):433-8. [Medline].
2. Snider RK, ed. Essentials of Musculoskeletal Care. Rosemont, Ill: American Academy of Orthopaedic Surgeons; 2000:336-8.
3. Griffin LY. Acute knee injuries. Sports Medicine. New York, NY: John Wiley & Sons, Inc; 1994:2255-60.
4. Krukhaug Y, Mølster A, Rodt A, Strand T. Lateral ligament injuries of the knee. Knee Surg Sports Traumatol Arthrosc. 1998;6(1):21-5. [Medline].
5. Bahk MS, Cosgarea AJ. Physical examination and imaging of the lateral collateral ligament and posterolateral corner of the knee. Sports Med Arthrosc. Mar 2006;14(1):12-9. [Medline].
6. Beall DP, Googe JD, Moss JT, et al. Magnetic resonance imaging of the collateral ligaments and the anatomic quadrants of the knee. Magn Reson Imaging Clin N Am. Feb 2007;15(1):53-72. [Medline].
7. Bolog N, Hodler J. MR imaging of the posterolateral corner of the knee. Skeletal Radiol. Aug 2007;36(8):715-28. [Medline].
8. Coobs BR, LaPrade RF, Griffith CJ, Nelson BJ. Biomechanical analysis of an isolated fibular (lateral) collateral ligament reconstruction using an autogenous semitendinosus graft. Am J Sports Med. Sep 2007;35(9):1521-7. [Medline].
9. Johnson D. Management of the multi-ligament injured knee. Paper presented at: Biannual Congress of International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine; 1999; Washington, DC.
10. Majewski M, Susanne H, Klaus S. Epidemiology of athletic knee injuries: A 10-year study. Knee. Jun 2006;13(3):184-8. [Medline].
11. Medvecky MJ, Zazulak BT, Hewett TE. A multidisciplinary approach to the evaluation, reconstruction and rehabilitation of the multi-ligament injured athlete. Sports Med. 2007;37(2):169-87. [Medline].
12. Murphy KP, Helgeson MD, Lehman RA Jr. Surgical treatment of acute lateral collateral ligament and posterolateral corner injuries. Sports Med Arthrosc. Mar 2006;14(1):23-7. [Medline].
13. Noyes FR, Barber-Westin SD. Posterolateral knee reconstruction with an anatomical bone-patellar tendon-bone reconstruction of the fibular collateral ligament. Am J Sports Med. Feb 2007;35(2):259-73. [Medline].
14. Paletta GA, Warren RF. Knee injuries and Alpine skiing. Treatment and rehabilitation. Sports Med. Jun 1994;17(6):411-23. [Medline].
15. Ruiz ME, Erickson SJ. Medial and lateral supporting structures of the knee. Normal MR imaging anatomy and pathologic findings. Magn Reson Imaging Clin N Am. Aug 1994;2(3):381-99. [Medline].

Article Last Updated: Oct 2, 2007