PCL Injury

Lower Limb

Overview

PCL injuries represent a significant knee ligament injury that occurs when the posterior cruciate ligament is stretched or torn, typically from direct anterior force to the proximal tibia or hyperextension mechanisms. These injuries are less common than ACL injuries but frequently occur in conjunction with other ligamentous injuries, potentially compromising knee stability and function. Early assessment and appropriate management are essential to prevent chronic instability and secondary degenerative changes.

Pathophysiology

The posterior cruciate ligament, originating from the medial femoral condyle and inserting on the posterior tibia, is the primary restraint to posterior tibial translation. When subjected to excessive force—particularly direct blow to the anterior proximal tibia, forced hyperextension, or combined rotational mechanisms—the ligament fibers undergo partial or complete disruption. This disruption impairs proprioceptive feedback and neuromuscular control, leading to altered knee biomechanics, increased tibiofemoral shear forces, and potential secondary damage to menisci, collateral ligaments, and articular cartilage. Grade I (partial tear) involves incomplete fiber disruption; Grade II represents significant partial tear with functional instability; Grade III indicates complete rupture with marked instability.

Patient Education

PCL injuries require early diagnosis and conservative management with graduated strengthening to restore dynamic stability; most isolated PCL injuries heal well without surgery if rehabilitation is consistent and activity is appropriately modified.

Typical Presentation

Site

Posterior and medial knee joint, with pain typically diffuse throughout the knee; posterolateral knee pain if posterolateral corner involved

Quality

Dull aching pain, sense of instability or 'giving way,' sensation of knee sliding backward

Intensity

Mild to moderate in isolated injuries (4-6/10); severe in acute complete tears or combined injuries (7-9/10); often less painful than ACL injuries acutely

Aggravating

Descending stairs, walking downhill, activities requiring deceleration, deep knee flexion, pivoting movements, sitting with knee flexed (posterior wall compression), prolonged standing or walking

Relieving

Rest and elevation, knee extension, ice application, anti-inflammatory medication, activity modification, knee bracing or taping

Associated

Posterior knee swelling (less obvious than ACL), sense of instability with cutting/pivoting, difficulty with running and jumping, pain with posterior tibial sag test, difficulty squatting, mild effusion, positive posterior drawer test, positive quadriceps active test

Orthopaedic Tests

Posterior Drawer Test

Procedure

Patient supine with knee flexed to 90°. Examiner stabilizes the foot and applies a posterior-directed force to the proximal tibia, comparing side-to-side displacement.

Positive Finding

Excessive posterior translation of the tibia relative to the femur, or asymmetry compared to the contralateral knee

Sensitivity / Specificity

89% / 97%

Rubinstein et al., 1994, American Journal of Sports Medicine

Interpretation

Positive test indicates PCL insufficiency. High specificity makes it reliable for ruling in PCL injury when positive.

Quadriceps Active Drawer Test

Procedure

Patient supine with knee flexed to 90°. Examiner applies gentle resistance as patient performs active quadriceps contraction, observing tibial position relative to femoral condyles.

Positive Finding

Anterior translation of the tibia during quadriceps contraction (pseudoreduction of posterior drawer), indicating active attempt to stabilise posterior subluxation

Sensitivity / Specificity

80% / 96%

Daniel et al., 1988, American Journal of Sports Medicine

Interpretation

May be more sensitive than passive posterior drawer, particularly for chronic PCL injuries where muscular stabilisation is more pronounced.

Posterior Sag Test (Gravity Drawer)

Procedure

Patient supine with hips and knees flexed to 90°. Examiner observes the tibial profile from the side without applying manual force, noting any posterior sagging of the tibia.

Positive Finding

Visible posterior displacement of the tibial tuberosity relative to the patellar tendon line, indicating tibial subluxation under gravity

Sensitivity / Specificity

79% / 98%

Lelli et al., 2014, Arthroscopy; Richter et al., 2019, Knee Surgery, Sports Traumatology, Arthroscopy

Interpretation

Excellent specificity; passive gravity-assisted test useful for detecting moderate to severe PCL insufficiency without confounding muscle guarding.

Dial Test (External Rotation Recurvatum Test)

Procedure

Patient supine with legs extended. Examiner lifts both feet by the heels, observing external tibial rotation and knee recurvatum. Knees are flexed to 70–80° and external rotation is compared bilaterally.

Positive Finding

Increased external rotation of the tibia (>10° difference) or recurvatum greater than the contralateral side

Sensitivity / Specificity

49% / 98%

Rubinstein et al., 1994, American Journal of Sports Medicine

Interpretation

Highly specific but low sensitivity; positive result suggests posterolateral instability. More sensitive for combined PCL/posterolateral corner injuries than isolated PCL tears.

Reverse Pivot Shift Test (Jakob Test)

Procedure

Patient supine with hip flexed to 45° and knee fully extended. Examiner applies valgus stress and external tibial rotation, then slowly flexes the knee while maintaining these forces, observing for sudden reduction of tibial position.

Positive Finding

Sudden 'clunk' or shift as the knee is flexed from extension, indicating sudden reduction of posterolateral tibial subluxation

Sensitivity / Specificity

See current literature / 98%

Interpretation

Highly specific for posterolateral instability, particularly in combination with PCL insufficiency. Low sensitivity limits utility as sole screening test.

PCL Stress Radiograph (Posterior Drawer Stress View)

Procedure

Patient prone or supine with knee flexed to 90°. Radiographer applies standardised posterior force to proximal tibia while obtaining lateral knee radiograph. Tibial translation is measured relative to femoral condyle.

Positive Finding

Greater than 5 mm posterior tibial translation at 90° knee flexion, or >3 mm side-to-side difference; asymmetry suggests PCL insufficiency

Sensitivity / Specificity

See current literature / See current literature

Interpretation

Objective imaging-based measure useful for grading PCL injury severity (Grade 1: 5–10 mm, Grade 2: 10–15 mm, Grade 3: >15 mm) and surgical planning.

⚠ Red Flags

  • •Acute severe trauma with inability to bear weight and significant swelling within 2 hours (suggests grade III tear or multi-ligament injury)
  • •Vascular compromise signs: absent pedal pulses, pale or cyanotic foot, severe swelling with compartment pain
  • •Signs of posterolateral corner injury with severe rotational instability
  • •Associated fractures of tibial plateau, femoral condyle, or fibular head
  • •Neurovascular deficit with peroneal nerve injury (foot drop, inability to dorsiflex)
  • •Signs of complex knee dislocation with multiple ligament injuries
  • •Uncontrolled swelling not responding to ice and compression within 48 hours

⚡ Yellow Flags

  • •Catastrophic thinking about knee function and return to sport
  • •Fear-avoidance beliefs regarding movement and activity, leading to deconditioning
  • •Delayed presentation (>2 weeks) with ongoing instability and functional loss
  • •High-level athlete with significant psychological distress regarding career implications
  • •Poor compliance with rehabilitation expectations or denial of injury severity
  • •Litigation or compensation issues related to injury circumstances
  • •History of previous knee injuries with incomplete rehabilitation
  • •Unrealistic expectations for rapid return to sport without appropriate progression

Osteopathic Techniques

Region

Quadriceps mechanism and vastus medialis obliquus

Technique

Soft Tissue

Rationale

Soft tissue mobilization to address quadriceps inhibition and restore dynamic stability; VMO activation is critical for dynamic posterior stability in isolated PCL injuries, reducing reliance on ligamentous restraint

Region

Hamstring and gastrocnemius muscles

Technique

MET

Rationale

Muscle energy techniques to release hamstring and gastrocnemius tightness; these muscles normally provide dynamic posterior support to the tibia and posterior capsule; releasing tension facilitates optimal loading patterns and hamstring strengthening effectiveness

Region

Knee joint complex with emphasis on tibiofemoral joint

Technique

Articulation

Rationale

Gentle articulation to maintain normal arthrokinematics and prevent capsular restriction; promotes synovial fluid nutrition to articular surfaces and maintains proprioceptive input through mechanoreceptor stimulation

Region

Posterior knee capsule, popliteal fossa, and posterolateral structures

Technique

Soft Tissue

Rationale

Deep soft tissue mobilization to address capsular inflammation and adhesion formation; improves circulation to healing tissues and reduces pain-mediated muscle guarding in posterior and posterolateral compartments

Region

Lumbar spine, hip flexors, and hip external rotators

Technique

MET

Rationale

Addresses proximal kinetic chain dysfunction; hip weakness and lumbar stiffness cause compensatory knee stress; restoring hip mobility and pelvis control reduces excessive tibiofemoral shear forces during functional activities

Region

Ankle and foot complex

Technique

Articulation

Rationale

Maintains distal kinetic chain mobility; ankle stiffness increases compensatory knee stress; optimizing ankle arthrokinematics distributes forces more efficiently through the lower limb during weight-bearing activities

Add-On Approaches

Chinese Medicine

Acupuncture targeting DU 32 (mingmen), UB 40 (weizhong), GB 34 (yanglingquan), and local ah-shi points; moxibustion to support qi circulation and reduce damp-cold obstruction in chronic cases; herbal support with jin gui shen qi wan (kidney yang warming formula) to support kidney-ligament connection in chronic instability

Chiropractic

Patellar mobilization techniques (medial and lateral glides) to optimize patellar tracking and quadriceps efficiency; knee manipulation if minor capsular restriction present; proprioceptive neuromuscular facilitation (PNF) patterns for lower limb stability and neuromuscular re-education

Physiotherapy

Isokinetic quadriceps and hamstring strengthening with emphasis on eccentric loading; closed-kinetic-chain exercises progressing from double-leg to single-leg stance; proprioceptive training on unstable surfaces; agility ladder and lateral band walk progressions for posterolateral stability; sport-specific functional training for return to activity

Remedial Massage

Deep longitudinal stripping to quadriceps, hamstring, and calf musculature; trigger point release to vastus medialis obliquus and medial hamstring; cross-friction techniques to address scar tissue in acute-to-subacute phases; myofascial release to address hip and pelvis restrictions contributing to knee dysfunction

Rehabilitation Exercises

Supine Knee Flexion and Extension

Range of MotionBeginner

Prone Knee Flexion Slides

Range of MotionBeginner

Supine Figure-Four Hamstring and Piriformis Stretch

StretchingBeginner

Gastrocnemius and Soleus Wall Calf Stretch

StretchingBeginner

Supine Quadriceps Setting with Towel Roll

StrengtheningBeginner

Straight Leg Raise (Supine)

StrengtheningBeginner

Seated Knee Extension with Resistance Band

StrengtheningIntermediate

Standing Hip Flexor Strengthening (Marching)

StrengtheningIntermediate

Standing Hip Abduction with Resistance Band

StrengtheningIntermediate

Prone Hamstring Curls with Resistance Band

StrengtheningIntermediate

Bilateral Stance Stability with Upper Body Movement

BalanceBeginner

Single-Leg Stance with Hand Support

BalanceIntermediate

Double-Leg Stance on Foam Pad

BalanceIntermediate

Wall Squats (Partial to Full Depth Progression)

PosturalIntermediate

Step-Ups on 4-6 Inch Step (Bilateral)

PosturalIntermediate

Sit-to-Stand from Chair

PosturalBeginner

Lateral Band Walk (Double Leg)

StrengtheningIntermediate

Clamshells (Hip External Rotation)

StrengtheningIntermediate

Quadruped Alternating Limb Extension

PosturalIntermediate

Single-Leg Stance on Unstable Surface

BalanceAdvanced

Single-Leg Squats (Assisted Progression)

StrengtheningAdvanced

Stationary Cycling (Upright, Moderate Resistance)

CardiovascularIntermediate

Referral Criteria

  • •Multi-ligament knee injuries requiring surgical consultation (especially posterolateral corner injuries with rotational instability)
  • •Acute grade III (complete) PCL tear in young athletic population considering surgical reconstruction
  • •Associated fractures (tibial plateau, femoral condyle, fibular head) requiring orthopedic specialist evaluation
  • •Vascular or neurological compromise requiring emergency vascular surgery consultation
  • •Unresolved swelling and effusion persisting beyond 4 weeks despite conservative management
  • •Persistent severe instability not improving with 6-8 weeks of appropriate rehabilitation
  • •Significant secondary meniscal or cartilage damage identified on imaging
  • •Failure to progress in rehabilitation or developing chronic pain syndrome features
  • •Athlete seeking clearance for high-impact sport return requiring sports medicine evaluation
  • •Suspected complex knee dislocation or posterolateral corner involvement requiring specialized imaging and assessment
  • •Development of persistent swelling with compartment syndrome concern
  • •Patient preference for surgical intervention after failure of conservative management trial