Cartilage T1rho quantification in acl-reconstructed knees: a 2-year follow-up

Abstract

s / Osteoarthritis and Cartilage 20 (2012) S10–S53 S20 considered severely degenerated. Two independent readers performed histological scoring of the PCLs (Inter-observer class coefficient 1⁄4 0.87). PCL scores were compared to ACL scores from same knees. Results: All knees had an intact, non-ruptured PCL. PCL grade: 76% of the knees showed a mild PCL degeneration; 12%, moderate; and 9%, severe. Fiber disorientation was the most prevalent and severe change (1.2 0.66) followed by mucoid denegation (0.84 0.77), chondroid metaplasia (0.81 0.73), cystic changes (0.54 0.87), and inflammation (0.46 0.66). All criteria showed strong correlations to the total PCL score (range r1⁄40.5-0.76), the highest being mucoid degeneration. Comparison of histological grades of PCL and ACL showed a close relationship with the exception that significantly fewer PCL than ACL were in the “severe” group (Figure 1). There was lower correlation between total histological PCL scores and aging (R1⁄40.29) compared to ACL scores and aging (r1⁄40.45). ACL scores correlated well with total cartilage scores (r1⁄40.56) while PCL scores increased with severity of OA from grades 0 to III but not between OA grades III to IV (r1⁄40.31, Figure 2). In knees with ruptured ACL, the PCL scores correlated with the cartilage score of the lateral compartment (femur r1⁄4 0.65, tibia r1⁄4 0.57). Conclusions: Significant percentages (w 25%) of patients with OA have a deficient ACL, while all PCL were macroscopically intact with weak correlations between PCL degeneration and aging. PCL histological scores were lower in knees with grade IV compared to grade III cartilage suggesting that the PCL is at lower risk for acute or chronic injury than the ACL. The PCL has a significantly different pattern of degeneration. The lack of correlation with age or OA grade indicates independent pathways for PCL versus ACL degeneration.