Cutting edge Orthopedics

40 • CUTTING EDGE - ORTHOPEDICS dislocation requires a careful neurologic and vascular examination. Even if physical findings such as normal pulses are present, the patient needs some type of documentation of vascular status due to the challenge of the same provider performing serial exams over the next 24–48 h. An ABI measurement can be done at any facility as a screening exam with a high sensitivity of detection of an operable vascular injury. If the ABI ratio is less than 0.9, one needs to consider another imaging study, such as a CT angiogram or arteriogram, as this is predictive of a vascular injury requiring repair [9]. While the patient’s neurological exam is normal, one must consider the peroneal nerve. Peroneal nerve injury is another complication associated with knee dislocations. In a case series of 55 dislocations of the knee, Niall and colleagues evaluated the incidence of peroneal nerve injuries [11]. They found peroneal nerve injuries in 14 of 55 patients (25%) when all knee disloca- tions were considered. They found a higher incidence of nerve injuries in knees with bicruciate injuries and concomitant posterolateral corner disruptions: 14 of 34 patients (41%). The incidence of peroneal nerve injuries in these injuries is most often quoted to be 20–30%. Finally, in terms of initial management of MS, one must consider immobilization of the extremity. Historically, patients with knee dislocations have been placed either in a cylinder splint, a knee immobilizer, a hinged knee brace, or an external fixator upon arrival to the hospital. If initial reduction is successful and the reduction is stable, a splint or hinged knee brace is likely adequate for immobilization until definitive surgery can be performed. A recent protocol, sug- gested by Levy and associates and used on nine consecutive patients successfully, recommends placement of an external fixator immediately in cases of knee dislocations with a vascular injury or open knee dislocations [12]. Furthermore, they recommend placement of an external fixator in cases where there is inability to maintain a reduction adequately in a brace or splint and in cases where the patient is unable to tolerate mobilization in a brace. Although this study has a relatively low number of patients, it provides an initial protocol to follow when considering whether a splint or hinged knee brace would be appropriate. Ultimately, placement of an external fixator should be guided by necessity. For example, external fixation may be appropriate for a patient requiring multiple trips to the operating room for debridement of wounds or surgical treatment of ipsilat- eral injuries on the limb. Declaration of Specific Diagnosis MS presents with a high-energy injury consistent with a multiligamentous knee injury with damage to his ACL, PCL, MCL, and posterolateral corner with no neurologic or vascular injury. Brainstorming: What Are the Treatment Goals and Options? Treatment goals consist of the following objectives: 1. Detect limb-threatening injuries 2. Restore stability of the knee