Available literature and quality of the evidence

• Level I: 1 retrospective cohort examining accuracy of MRI⁵ and 1 randomized controlled trial (RCT) examining physical exam versus MRI.⁶
  
• Level III: 1 systematic review examining physical exam versus reference standard: arthrotomy, arthroscopy, or MRI.⁷
  
• Level IV: 3 case series examining accuracy of MRI.⁸–¹⁰

Findings

The last double‐blinded, RCT examining clinical tests for PCL insufficiency was performed in 1994 by Rubinstein et al.⁶ Using direct comparison to MRI, the study found that there was a 96% overall clinical examination accuracy in diagnosing chronic PCL injuries amongst sports medicine fellowship‐trained orthopedic surgeons, with a 90% sensitivity and 99% specificity in detecting a PCL tear. However, interobserver disagreement about the grade of injury existed in 19% of cases. The posterior drawer test was found to be the most sensitive and specific clinical test; however, for grade 1 laxity it was found to only have a sensitivity of 70%. A systematic review of level II and III studies by Kopkow et al. concluded that the diagnostic accuracy of physical exam tests for PCL injury was largely unknown due to poor quality evidence with high risk of bias.⁷ Multiple level III⁵ and IV⁸,⁹ studies have suggested that the accuracy of MRI for the diagnosis of acute PCL injury approaches 100%. Its accuracy for chronic PCL injuries, on the other hand, has been shown to be as low as 57% in a level IV case series by Servant et al.¹⁰

Another method of diagnosis to consider for PCL injuries not included in the studies above is posterior stress radiography, which can be superior to arthrometric evaluation in quantifying posterior tibial translation.¹¹ Its efficacy and comparison to MRI need to be studied further.

Resolution of clinical scenario

• One level I study suggests that the overall clinical examination accuracy in diagnosing chronic PCL injuries is excellent (96%).
  
• The majority of studies examining diagnostic accuracy of physical exam for PCL injury are old and contain high risk of bias.
  
• Level III and IV studies suggest the accuracy, specificity, and sensitivity of MRI in detecting acute PCL injury approaches 100% but is much less accurate for chronic PCL injury.
  
• Return to case: for the male goalkeeper with a mechanism of injury concerning for PCL injury, MRI would be helpful in the acute setting for diagnosis. Clinical examination is nearly as accurate as MRI if assessed in the chronic setting. However, MRI may still be helpful to rule out associated pathology, such as posterolateral corner (PLC) injury, or for preoperative planning.