The diagnosis of PCL injury: literature review and introduction of two novel tests

Abstract

Isolated PCL injuries have become more prevalent in recent years, possibly as a result of improved awareness and clinical recognition. However, the diagnosis can be difficult, and many of these injuries continue to go undiagnosed. Several clinical tests for PCL laxity have been described over the years, with varying degrees of sensitivity and clinical applicability. These include the posterior drawer, the Muller Quadriceps Active Test, Godfrey's Test, Trillat's reverse lachman/total translation test, and the Dynamic Posterior Shift. All of these tests require significant posterior laxity associated with complete PCL disruption to be positive. Use of the KT-1000 arthrometer, and several radiographic tests have also been developed to help with diagnosis and quantification of laxity. It is the purpose of this paper to review the technique and application of the established diagnostic tests for PCL deficiency, and to introduce two new tests employed by the senior author for nearly three decades. It is the authors' experience that these new tests are sufficiently sensitive to allow the examiner to detect the presence of PCL insufficiency even in the most difficult diagnostic situations with subtle laxity.

Figure 1. Performance of the Posterior Functional Drawer Test in the prone position at 90°

Examiner compares strength of hamstrings and patient reports the presence of posterior pain.

Figure 2. Performance of the Posterior Functional Drawer Test in the prone position at 20°

Examiner compares strength of hamstrings to each other, and to the 90° test, and patient reports the presence of posterior pain.

Figure 3. Performance of the Posterior Functional Drawer Test in the supine position at 90°

Examiner compares strength of hamstrings and patient reports the presence of posterior pain.

Figure 4. Performance of the Posterior Functional Drawer Test in the prone position at 20°

Examiner compares strength of hamstrings to each other, and to the 90° test, and patient reports the presence of posterior pain.

Figure 5. Posterior Functional Drawer test with an anterior drawer applied

This symptomatic patient had reduced pain and increased hamstring strength with this maneuver.

Figure 6. Performance of the Proximal Tibial Pecussion test to the relaxed, unsuspecting patient

A positive test illicits significant posterior pain. This is very useful in the acute injury setting.

Figure 7

A grade II posterior drawer. Translation was estimated at 10mm, and condyles are flush with proximal tibial plateau. Note sag of anterior tibial silhouette.

Figure 8

First part of Godfrey's test. Note sag of anterior tibia. The sag is more pronounced than that seen in Figure 7.

Figure 9

Second part of Godfrey's test. Proximal tibia translates anteriorly with resisted initiation of knee extension.