Posterior Cruciate Ligament Injury Workup

Updated: Aug 11, 2022
  • Author: Charles S Peterson, MD; Chief Editor: Craig C Young, MD  more...
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Laboratory and Imaging Studies

Laboratory studies

Perform laboratory studies as indicated per patient age.

Imaging studies


  • Acute injuries

    • Routine radiographs usually are negative in acute injuries.

    • Bony avulsions may be evident on lateral radiographs.

    • New radiological view: Axial radiograph as described by Puddu et al. Patient is supine with knees flexed to 70°, feet are plantigraded in moderate plantar flexion, and the tibia is in neutral rotation. With patient holding cassette, the radiographic beam is directed distal to proximal and parallel to the longitudinal axis of the patella. The length of the perpendicular line between the anterior tibial profile and the femoral groove is measured. If the side-to-side difference is >3 mm, posterior laxity is indicated.

  • Chronic lesions

    • Weight-bearing anteroposterior (AP) or Rosenberg view (posteroanterior [PA] with knees flexed) may demonstrate early medial joint arthrosis.

    • Tangential patellofemoral view (Laurin/Merchant view) may demonstrate patellofemoral arthrosis.

    • Long-film AP weight-bearing views are essential for preoperative alignment.

Magnetic resonance imaging (MRI)

  • If physical examination reveals multiple injured ligaments, or if degree of injury is in question, an MRI may be justified.

  • MRI helps identify and confirm the location of the lesion; in addition, occult osteochondral lesion/fractures and meniscal lesions may be identified. MRI of acute injury is more accurate than for chronic injury, as the ligament may appear healed but be functionally deficient. [8]  (See the images below.)

    This MRI of the knee shows a torn posterior crucia This MRI of the knee shows a torn posterior cruciate ligament.
    This MRI (coronal section) shows a posterior cruci This MRI (coronal section) shows a posterior cruciate ligament tear.
    This transverse MRI shows edema to the torn poster This transverse MRI shows edema to the torn posterior cruciate ligament.

Other Tests and Procedures

Other tests

Occasionally, a patient with a posterior knee injury may present with calf pain and signs of an impending compartment syndrome, possibly due to soft tissue injury or signs of an occult vascular injury. The calf symptoms may be more pronounced than the knee symptoms. Compartment pressures need to be measured, and vascular surgery consultation must be considered for an arteriogram.


Perform an arteriogram in patients with suspected vascular injury, such as an injury that might be seen with knee dislocation.

Arthroscopic posteromedial drive-through test can reveal PCL rupture (grade III PCL instability). The test is positive if it is easy to pass the arthroscope between the medial femoral condyle and the PCL. This test had an overall accuracy of 97.6%. [9]