Fractures of the posterolateral tibial plateau.

We reviewed the clinical records and operative notes of 28 patients with fractures of the posterolateral tibial plateau seen at our institution from 1949 to 1982. Five of the 28 patients had chronic depressions of the posterolateral tibial plateau after initial treatment elsewhere. All five were disabled because of significant functional instability when the knee was in flexion. There were 23 acute fractures, of which 4 were initially nondisplaced and treated nonoperatively. One nonoperative patient was lost to followup; the remaining three were rated as having had good or excellent results. Nineteen patients had acute depressed fractures and were treated operatively with open reduction, elevation of the depressed area, and bone grafting, with or without internal fixation. All patients treated operatively at the time of injury were seen for followup from 24 to 145 months postoperatively, with a mean followup of 59 months. One patient was lost to followup; the other 18 were rated using both objective and subjective criteria. Seventeen (94%) achieved a final rating of excellent or good; one patient (6%) achieved a rating of fair. We have observed these fractures occurring in a younger population and producing significant disability in activities requiring a stable knee in flexion. The depressed posterolateral tibial plateau fracture is best assessed by AP, lateral, and 45 degrees internal oblique views on radiographic examination. Because of continued disability caused by chronic, depressed fractures of this type, we recommend open reduction and bone grafting in acute cases to eliminate instability in flexion. This procedure produces good or excellent results in most cases.