High-energy fractures of the tibial plateau. Knee function after longer follow-up.

BACKGROUND: Studies of the long-term outcomes of treatment of fractures of the tibial plateau have included wide mixtures of fracture types and mostly low-energy split and split-depression fractures. The long-term results of treatment of high-energy intra-articular proximal tibial fractures are unknown. The purpose of this study was to assess the function of the knee and the development of arthrosis at a minimum of five years after injury in a consecutive series of patients in whom a high-energy fracture of the tibial plateau had been treated with a uniform technique of external fixation.
METHODS: Between July 1988 and December 1994, thirty patients with a total of thirty-one fractures of the tibial plateau were treated with a monolateral external fixator and limited internal fixation of the articular surface. Follow-up data on twenty-four knees in twenty-three patients were obtained at a mean of ninety-eight months. Twenty patients (twenty knees) returned specifically for the study, at which time they completed an Iowa Knee Score questionnaire and a Short Form-36 (SF-36) general health survey, a physical examination was performed, and weight-bearing radiographs were made. The results of the SF-36 evaluations for fourteen patients and the Knee Scores for twelve were compared with those obtained five years previously, at two to four years after the injury.
RESULTS: After healing, no patient required a secondary reconstructive procedure. The range of motion of the knee averaged 3 degrees of extension to 120 degrees flexion, which was an average of 87% of the total arc of the contralateral knee. The average Iowa Knee Score was 90 points (range, 72 to 100 points). For twelve patients, the Iowa Knee Score previously recorded at two to four years averaged 92 points, as did the score at the time of the latest follow-up. Thirteen patients rated their outcome as excellent; six, as good; and three, as fair. Fifteen patients were working, and ten of them were performing strenuous labor. Radiographs showed no evidence of arthrosis in fourteen knees, grade-1 arthrosis in three, grade-2 in three, and grade-3 in two. Compared with the radiographic appearance two to four years after injury, there was no evidence of progression of arthrosis in eighteen knees and one grade of progression in four. The SF-36 subscale scores were similar to those of age-matched controls. The fourteen patients who had previous SF-36 scores had no deterioration of these scores.
CONCLUSIONS: Patients with a high-energy fracture of the tibial plateau treated with external fixation have a good prognosis for satisfactory knee function in the second five years after injury. The knee joint cartilage appears to be tolerant of both the injury and mild-to-moderate residual articular displacement, which was associated with a low rate of severe arthrosis.