Godfrey test
Reading File
Searching the Web
Godfrey test PCL posterior cruciate ligament clinical examination
Finding Sources
Finding Sources
Reading Web Page
Godfrey test posterior sag sign PCL examination technique sensitivity specificity
Reading File
Reading File
Godfrey Test (Posterior Sag Sign)
The Godfrey test, also called the posterior sag sign, is a clinical examination test used to assess the integrity of the posterior cruciate ligament (PCL).
Anatomy & Background
The PCL is the primary restraint to posterior tibial translation, particularly between 30° and 90° of knee flexion. At 90° of flexion it controls the majority of posterior tibial translation. - Bailey and Love's Short Practice of Surgery, 28th Ed.
Technique
- The patient lies supine.
- A pillow is placed under the distal thigh for support, with the heel resting on the examination table (alternatively, the examiner supports the leg).
- The hip and knee are both flexed to 90° (some sources accept 45°-90° of knee flexion).
- The examiner observes the profile of both knees from the side, comparing the height of the tibial tuberosities.
Positive test: The tibia sags posteriorly (gravity-dependent drop) relative to the femur, creating an abnormal contour at the proximal anterior tibia. This indicates PCL insufficiency.
Sensitivity & Specificity
| Parameter | Value |
|---|---|
| Sensitivity (acute phase) | 79% |
| Specificity | High (especially when combined with other PCL tests) |
Rosen's Emergency Medicine, Concepts and Clinical Practice
According to a systematic review by Kopkow et al., the posterior sag sign is the most sensitive test for PCL deficiency, while the quadriceps active test is the most specific. - PCL Current Concepts Review (PMC)
Important Clinical Note
A false-positive anterior drawer test can occur if the examiner fails to recognize a posterior sag sign - the tibia appears to translate forward simply because it started in a posteriorly displaced (sagging) position. This is why you should always check for the posterior sag before performing the anterior or posterior drawer test.
Comparison with Other PCL Tests
| Test | Notes |
|---|---|
| Godfrey test (posterior sag sign) | Gravity-dependent; most sensitive; passive test |
| Posterior drawer test | Most reliable overall; sensitivity ~85-90%, specificity ~99% |
| Quadriceps active test | Most specific; patient contracts quads to dynamically reduce a sagging tibia |
| Dial test | Assesses combined PCL + posterolateral corner (PLC) injury |
Clinical Implication
A positive Godfrey test should prompt further evaluation with the posterior drawer test and imaging. MRI has near-100% sensitivity and specificity for acute PCL tears, though it may be less reliable for chronic injuries where the PCL can heal with residual laxity.
This is a shared conversation. Sign in to Orris to start your own chat.