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The authors are from the Department of Orthopaedic Surgery, University of Kentucky School of Medicine, Lexington, Kentucky.
The authors have no relevant financial relationships to disclose.
Multiligamentous knee injuries can be devastating and life changing. Fortunately, they are not common. Even more rare is a multiligamentous knee injury concomitant with a patellar tendon rupture or extensor mechanism disruption. There have been a few case reports of simultaneous anterior cruciate ligament (ACL) and patellar tendon ruptures.1-6 The current authors present 2 cases of a multiligamentous knee injury with a patellar tendon rupture that highlight a treatment algorithm for these complex cases.
During an initial examination of an individual with gross knee laxity, one must have a high index of suspicion for possible knee dislocation to avoid the potential for catastrophic results. It is estimated that more than 50% of knee dislocations spontaneously reduce. A knee dislocation places all of the structures surrounding the knee at risk for injury, but by definition at least 2 of the 4 primary ligamentous stabilizers must be disrupted. The structures most commonly injured from a knee dislocation are the ACL and the medial collateral ligament (MCL).
A concern with this injury is a missed diagnosis of the extensor mechanism. Examination of the knee may be difficult. Occasionally in a trauma patient, other distracting injuries may take precedence and a thorough knee examination may initially be overlooked. Once an evaluation is performed, focus may be drawn toward one injury and a simultaneous injury may be overshadowed. A few published case reports demonstrate how easy it is to miss a patellar rupture or a knee ligament tear when these injuries occur simultaneously. Tsarouhas et al6 reviewed 13 cases from the literature and found that 5 ACL tear diagnoses and 1 patellar tendon diagnosis were initially missed. However, associated knee pathology with a patellar tendon rupture may be more common than what is routinely identified. Patellar tendon ruptures have an associated injury 30% of the time.7 The most common injuries are an ACL tear and a meniscus tear, both occurring 18% of the time. It was also found that approximately 1 of every 4 patellar tendon ruptures has more than 1 associated injury.
Case Reports
Patient 1
A 32-year-old man was involved in a...