Thien Dang, Lawrence M White, Ali Naraghi, Dawn H Pearce, Daniel B Whelan
Although a high prevalence of peritunnel edema, increased graft signal and thickness and synovitis/arthrofibrosis may be encountered early postoperatively, particularly in the first 12 months; these findings are not correlated to PCL instability and seem to decrease over longer-term follow-up.
OBJECTIVE: The study aims to characterize the postoperative MRI appearance of double-bundle PCL graft reconstructions (DB-PCL-R) with correlation to clinical PCL stability.
METHODS: A retrospective evaluation of 23 patients, 37 MRIs (12/37, 0-3 months; 8/37, 3-12 months; 17/37, > 12 months) following DB-PCL-R for MRI findings, integrity of the anterolateral (ALB) and posteromedial (PMB) bundles, position of tunnels, peritunnel marrow edema, graft fixation, graft signal, graft-bundle thickening, and synovitis or arthrofibrosis was performed. MRI findings were categorized by time interval postoperatively. PCL stability was assessed clinically (grade 0-III) in all patients. Chi-square or Fisher's exact analysis was performed to explore associations between MRI findings and PCL stability.
RESULTS: Graft bundles appeared intact in all cases. PMB graft femoral tunnel was inferiorly positioned in 2/23 patients. The tibial tunnel was inferiorly positioned in 5/23 and superiorly positioned in 2/23 patients. Displaced/fractured fixation hardware related to the PMB tunnel was observed in 3/23 patients, and in the tibial tunnel in 2/23 patients. The highest prevalence of peritunnel marrow edema (50-81.8%) was observed 0-3 months postoperatively, which decreased progressively with increasing timeframe postoperatively. The highest prevalence of increased graft signal (25-62.5%) and graft thickening (25-37.5%) was seen 3-12 months postoperatively, with subsequent decrease on exams > 12 months postoperatively. Synovitis or arthrofibrosis was observed in 87.5% of exams obtained 3-12 months postoperatively, with a decrease (58.8%) on MRI exams > 12 months post-surgery. No significant correlation was observed between MRI variables and PCL stability (p-values, 0.085-0.815).
CONCLUSIONS: Although a high prevalence of peritunnel edema, increased graft signal and thickness and synovitis/arthrofibrosis may be encountered early postoperatively, particularly in the first 12 months; these findings are not correlated to PCL instability and seem to decrease over longer-term follow-up.