LCL Sprain

Lower Limb

Overview

LCL sprain is an injury to the lateral collateral ligament of the knee, commonly occurring from inversion stress or varus forces during sports or trauma. This ligament provides critical lateral stability to the knee joint and, when compromised, results in pain, swelling, and functional instability. Most LCL sprains are grade I-II injuries that respond well to conservative management, though grade III sprains may involve additional posterolateral corner structures.

Pathophysiology

The lateral collateral ligament (LCL) is an extracapsular ligament running from the lateral femoral condyle to the fibular head, providing primary restraint to varus stress and lateral knee translation. Injury mechanisms typically involve forced varus angulation, external rotation of the tibia on a fixed femur, or sudden deceleration with cutting movements. Acute sprain causes microtrauma with inflammatory exudate, disruption of collagen fibers, and activation of nociceptors. Chronic instability may develop if proprioceptive deficits persist and rehabilitation is incomplete, potentially predisposing to osteoarthritis.

Patient Education

Recovery from LCL sprains requires progressive weight-bearing restoration and proprioceptive retraining; early protection followed by gradual loading prevents chronic instability and ensures safe return to activity.

Typical Presentation

Site

Lateral knee over the fibular head and lateral femoral condyle; pain may radiate to the lateral thigh and calf depending on grade of injury

Quality

Sharp, stabbing pain at injury onset progressing to dull ache; sensation of lateral knee giving way or 'stepping off' during weight-bearing

Intensity

Grade I: mild pain (3-4/10) with minimal swelling; Grade II: moderate pain (5-7/10) with significant swelling; Grade III: severe pain (8-10/10) with gross instability

Aggravating

Varus stress, weight-bearing on affected leg, cutting/pivoting movements, external rotation of tibia, walking on uneven surfaces, ascending stairs

Relieving

Rest, elevation, ice application, mild compression, non-weight-bearing positioning, gentle pendulum exercises

Associated

Lateral knee swelling and bruising, lateral joint line tenderness, positive varus stress test, lateral knee instability, restriction of knee flexion/extension, difficulty weight-bearing, possible associated posterolateral corner injury (grade III)

Orthopaedic Tests

Test descriptions are written with AI assistance from standard clinical texts. Where a test lists Sources, its description has been checked against them; those sources are independent and do not endorse OsteoKit. Accuracy figures and grades (A–D) appear only when checked against the published study; tests without one are marked “No accuracy study”.

Further reading: full test procedures are described in standard clinical examination texts, e.g. Magee & Manske, Orthopedic Physical Assessment (7th ed.), and Cook & Hegedus, Orthopedic Physical Examination Tests: An Evidence-Based Approach (2nd ed.).

No accuracy study

Varus Stress Test (Varus Laxity Test)

Procedure

Patient supine, relaxed. Support the leg with the knee bent to 20–30°, one hand on the inner knee and one at the ankle, and apply a gentle outward (varus) force. Repeat with the knee fully straight. Compare with the other knee.

Positive Finding

Pain on the outer knee, or more gapping of the outer joint line than on the other side.

Interpretation

Pain without extra gapping fits a mild sprain; gapping suggests a more serious injury. Gapping with the knee straight suggests a combined injury (cruciate ligament or posterolateral corner) and needs urgent orthopaedic referral. Check common peroneal nerve function (ankle dorsiflexion, sensation on the top of the foot). The varus stress test is the primary clinical test for LCL integrity, but high-quality diagnostic-accuracy data are lacking; the previously cited source did not support the figures shown.

Sources

No accuracy study

Posterolateral Drawer Test

Procedure

Patient supine, hip bent to 45° and knee to 80–90°, foot turned out about 15°. Sit gently on the foot and push the tibia backwards, watching whether the outer plateau rotates backwards more than the inner.

Positive Finding

The outer tibial plateau rotates backwards more than on the other knee.

Interpretation

Suggests a posterolateral corner injury. This entry previously described the test with the patient prone, which is incorrect.

Sources

No accuracy study

Dial Test

Procedure

Patient prone. Bend both knees to 30°, hold the feet and rotate both tibias outwards equally, and compare the angle between the foot and thigh on each side. Repeat at 90°.

Positive Finding

More external rotation on the injured side.

Interpretation

More rotation at 30° only suggests a posterolateral corner injury; at both 30° and 90° it suggests a combined posterolateral corner and posterior cruciate ligament injury. An isolated LCL sprain usually has a normal dial test. The dial test assesses posterolateral corner rotational laxity; robust isolated sensitivity/specificity are not established and the previously cited source did not support the figures shown.

Sources

No accuracy study

External Rotation Recurvatum Test

Procedure

Patient supine, legs relaxed. Lift both legs by the big toes and compare how much each knee falls into hyperextension, outward bowing and tibial external rotation.

Positive Finding

The injured knee falls into more hyperextension and varus than the other.

Interpretation

Suggests a posterolateral corner injury, often combined with a cruciate ligament injury. The Losse test is a different test (a pivot-shift variant); the name has been corrected.

Sources

No accuracy study

Fibular Head Palpation & Mobility Assessment

Procedure

Patient supine, knee bent. Palpate the LCL as a cord from the lateral femoral epicondyle to the fibular head (easiest with the ankle on the opposite knee, figure-4 position), then the fibular head itself.

Positive Finding

Tenderness along the LCL or at its insertion on the fibular head.

Interpretation

Locates the injury. The fibular head is where the LCL inserts. Movement of the fibular head mainly reflects the proximal tibiofibular joint, not the LCL. A fracture of the fibular head needs X-ray.

Sources

No accuracy study

Combined Varus Stress Test with Tibial External Rotation

Procedure

Patient supine, knee bent to 20–30°. Apply a gentle varus force while slightly rotating the tibia outwards, palpating the outer joint line.

Positive Finding

Pain or gapping at the outer joint line.

Interpretation

Not a recognised named test. It loads the LCL and posterolateral structures together. Use the standard varus stress, dial and posterolateral drawer tests to assess these structures.

Further reading

⚠ Red Flags

  • •Signs of posterolateral corner injury (positive dial test, external rotation recurvatum sign) suggesting grade III injury requiring surgical consultation
  • •Acute severe swelling with inability to move knee suggesting associated intra-articular injury or fracture
  • •Signs of compartment syndrome (pain out of proportion, paresthesia, pallor) requiring urgent medical assessment
  • •Associated neurovascular compromise with distal pulses absent or neurological deficits present
  • •Fracture of fibular head or lateral femoral condyle on imaging

⚡ Yellow Flags

  • •Fear-avoidance beliefs limiting early mobilization and rehabilitation engagement
  • •Catastrophizing about chronic instability or future re-injury affecting compliance
  • •Work or sport-related pressure leading to premature return to activity and re-injury risk
  • •History of multiple ligament injuries suggesting possible proprioceptive deficits or technique flaws
  • •Low health literacy or poor understanding of injury severity affecting self-management

Osteopathic Techniques

Isolated grade 1–2 LCL tears with no instability at 0° are managed without surgery: about a week on crutches and a hinged knee brace for 3–6 weeks.

Safety: Unlike the MCL, the LCL does not heal on its own, so surgeons have a low threshold to operate, especially with other knee injuries. Keep ice to 15 minutes at a time on the outer knee to protect the common peroneal nerve.

Region

Lateral knee and fibular head

Technique

Soft tissue, knee and quadricepsNo trials found

Rationale

Hands-on work to the quadriceps and the tissues around the knee to ease tension and pain.

How it's done & evidence

How it's done

Hands-on kneading, stroking and sustained pressure to the quadriceps, the patellar and quadriceps tendons, the iliotibial band near the knee and the tissues around the joint. Transverse friction massage across a tendon is one form. In trials it was given alongside exercise.

Evidence in LCL Sprain

Searched 24 Oct 2026: no trials of soft tissue technique in LCL sprains.

Region

Tibiofemoral and patellofemoral joints

Technique

Articulation, knee (tibiofemoral and patellofemoral)No trials found

Rationale

Gentle, rhythmic glides of the knee and kneecap within their range to ease pain and stiffness.

How it's done, cautions & evidence

How it's done

Passive, low-velocity glides of the knee within its range, with no thrust: distraction and front-to-back glides of the tibia on the femur, and glides of the kneecap in each direction, usually 2–3 oscillations a second for 1–2 minutes. A Mulligan variant holds a sustained glide of the tibia while the patient actively bends and straightens the knee.

Cautions

In knee osteoarthritis trials, no serious adverse events were reported with manual therapy.

Evidence in LCL Sprain

Searched 24 Oct 2026: no trials of knee mobilisation in LCL sprains.

Region

Proximal tibiofibular joint (fibular head)

Technique

Muscle energy, fibular head (proximal tibiofibular joint)No trials found

Rationale

Gentle ankle contractions against resistance to restore fibular head movement.

How it's done, cautions & evidence

How it's done

Patient supine or seated with the knee bent to 90°. Draw the fibular head toward its restricted direction while taking the foot to its barrier (plantarflexion and supination, or dorsiflexion and pronation). The patient pushes the ankle gently against resistance for 3–5 seconds, relaxes, and the new barrier is taken up. Repeat 3–5 times, then re-check fibular head motion.

Cautions

Not used with an acute ankle sprain or a lax ankle, an acute fibular fracture or a deep vein thrombosis, or when positioning could aggravate an acute injury.

Evidence in LCL Sprain

Searched 24 Oct 2026: no trials of fibular head MET in LCL sprains.

Region

Hip and thigh muscles

Technique

Muscle energy, hip and thigh musclesNo trials found

Rationale

Low-force, patient-powered stretch for tight hip and thigh muscles.

How it's done, cautions & evidence

How it's done

The muscle (for example the hamstrings, adductors or rectus femoris) is taken to its barrier. The patient pushes gently, at about 10–20% effort, against resistance for 5–10 seconds, relaxes for 3–5 seconds, and the new barrier is taken up.

Cautions

Not used with an acute fracture, a joint infection or a bone malignancy; take care with severe osteoporosis or after surgery that limits muscle contraction. Use the least force needed: too much can tear a muscle or pull off a tendon, especially in older patients.

Evidence in LCL Sprain

Searched 24 Oct 2026: no trials of hip muscle energy technique in LCL sprains.

Rehabilitation Exercises

Supine Knee Flexion Slides

Range of MotionBeginner

Prone Hip Extension with Knee Flexion

Range of MotionBeginner

Supine Iliotibial Band Stretch

StretchingBeginner

Gastrocnemius and Soleus Calf Stretch

StretchingBeginner

Supine Hip Abduction with Resistance Band

StrengtheningIntermediate

Side-Lying Hip Abduction

StrengtheningIntermediate

Quadriceps Setting with Vastus Medialis Emphasis

StrengtheningBeginner

Clam Shell Exercise for Hip External Rotators

StrengtheningIntermediate

Single-Leg Stance on Firm Surface

BalanceIntermediate

Single-Leg Stance on Balance Board

BalanceAdvanced

Wall Squats with Neutral Knee Alignment

PosturalIntermediate

Stationary Cycling with Resistance Progression

CardiovascularIntermediate

Referral Criteria

  • •Positive varus stress test combined with dial test suggesting posterolateral corner involvement; refer to orthopedic surgeon for possible imaging and surgical consultation
  • •Persistent instability beyond 6 weeks of conservative management or recurrent giving way during daily activities
  • •Associated fracture of fibular head, fibular shaft, or lateral femoral condyle requiring orthopedic management
  • •Signs of complex regional pain syndrome (disproportionate pain, swelling, skin color changes) requiring specialist pain management
  • •Failure to progress in rehabilitation despite 4-6 weeks of compliant physiotherapy; refer back to physiotherapy for advanced proprioceptive retraining
  • •Concurrent meniscal symptoms (locking, catching, effusion) suggesting intra-articular pathology requiring MRI and specialist consultation