Plain radiographic findings in anterior cruciate ligament injury and repair

Abstract

T he anterior cruciate ligament (ACL) is one of the most important stabilizers of the knee (1). Although magnetic resonance imaging (MILl) unquestionably is the most accurate noninvasive method for evaluating this ligament, at least five indirect plain radiographic signs indicating ACL injury have been described. Many, if not most, patients with an ACL tear will have normal plain radiographs, but radiologists should be able to recognize those subtle findings that indicate ligamentous injury. In this article, we will review the normal anatomy and function of the ACE, mechanisms of injury, and plain radiographic signs ofligamentous injury. We will also discuss ACL repair principles and complications.

Injuries About the Knee and Tibial/Fibular Shafts

“…Most patients with soft tissue injuries about the knee have normal radiographs, but several plain film findings of injury have been described. 3,4,6,[11][12][13][14][15][16][17][18][19] Radiologists should be familiar with these signs of injury so that patients can be expeditiously referred for appropriate imaging or treatment. Five plain radiographic signs of ACL injury have been described.…”

“…12). 3,4,11,12 In these cases, the ligament itself is intact and repair can be affected simply by reattaching the avulsed bone fragment to the tibia. This type of injury is rare in adults but somewhat more common in children ( Fig.…”

“…Disruption of both the ACL and all secondary restraints to anterior tibial subluxation are required to produce this finding. 12 To our knowledge, avulsion of the tibial attachment site of the PCL is the only plain radiographic sign of PCL injury (Fig. 17).…”