Posterior Cruciate Ligament Pathology Clinical Presentation

Updated: May 11, 2018
  • Author: Matthew Lawless, MD; Chief Editor: Thomas M DeBerardino, MD  more...
  • Print
Presentation

History

Patients with acute posterior cruciate ligament (PCL) injuries have a presentation similar to that of patients with most other knee injuries. Patients with acute isolated PCL injuries often have minimal symptoms consisting of pain, swelling, and instability. In many cases, a near-normal gait pattern is seen. [36]

Next:

Physical Examination

PCL injury should be suspected at the time of physical examination of any acute knee injury. (See the image below.) Complete examinations of the contralateral and injured knees should be performed for comparison. If a PCL insufficiency is noted, care must be taken to evaluate the competency of the posterolateral corner.

Clinical examination photograph of a ruptured post Clinical examination photograph of a ruptured posterior cruciate ligament (PCL) confirmed on a posterior sagittal radiograph. Image courtesy of Mervyn J. Cross, MBBS, FRACS.

With acute isolated PCL injuries, patients typically do not have joint-line tenderness. An effusion may or may not be present. Varus, valgus, and rotational stressing reveal no instability.

The posterior drawer test is the most reliable indicator during physical examination for a PCL injury. [37, 38]  Positive posterior drawer test results are graded as follows:

  • Grade 1 - Laxity is noted compared with the contralateral knee, but the tibia remains anterior to the anterior aspect of the femoral condyles
  • Grade 2 - The anterior tibia can be subluxated equal to the anterior aspect of the femoral condyles
  • Grade 3 - The tibia subluxates posterior to the anterior aspect of the femoral condyles

With internal rotation, the posterior drawer test may elicit normal results for a PCL-insufficient knee because of the secondary restraint effect of the meniscofemoral ligaments. [39]  If more than 10 mm of posterior tibial translation is noted at 90° of knee flexion, a combined PCL and posterolateral corner injury is present. The posterior drawer test result demonstrates more than 10 mm posterior translation at 30° of knee flexion when the posterolateral corner is disrupted, either in isolation or in combination with a PCL injury.

The dial test helps identify an associated or isolated posterolateral corner injury. Greater than 10° of increased external rotation of the leg compared with the contralateral leg at 30° and 90° of knee flexion is a positive finding signifying a posterolateral corner injury with a PCL injury. [2]  A posterolateral corner injury has increased external rotation at 30º of flexion that (with PCL injury) stays the same or increases at 90º of flexion, whereas, at 90º of flexion without a PCL injury, less external rotation occurs.

Care must be taken in evaluating a knee with a positive dial test result to note that the lateral tibial plateau is subluxating posteriorly so that anterior subluxation of the medial tibial plateau secondary to an anterior cruciate ligament(ACL) and/or medial collateral ligament (MCL) disruption is not misinterpreted. [40]

The posterior sag, quadriceps active, external rotation recurvatum, and reverse pivot shift tests also aid in evaluating an acutely injured knee for PCL pathology. [41]  (See the images below.)

The photo on the left demonstrates the clinical fi The photo on the left demonstrates the clinical finding of the posterior tibia sag sign. A line drawn parallel to the patella accentuates the posterior tibia sag. The photo on the right demonstrates the quadriceps active drawer test described by Daniels; with the knee in 70-90° of flexion, the extensor mechanism is contracted, pulling the tibia anteriorly into a reduced position. Image courtesy of Janos P. Ertl, MD.
Close-up view of a posterior tibia sag with an inc Close-up view of a posterior tibia sag with an incompetent posterior cruciate ligament (PCL). Image courtesy of Janos P. Ertl, MD.
Posterior sag of the left posterior cruciate ligam Posterior sag of the left posterior cruciate ligament–deficient knee in comparison to the right knee. Note the posterior subluxation of the tibia relative to the femur of the left knee. Image courtesy of Robert Bronstein, MD.
Previous