Relationship between meniscal integrity and risk factors for cartilage degeneration

• KL grade was correlated with T2* relaxation time.
• Meniscal tears were present in all KL 3 and KL 4 cases.
• Significant increase in meniscal extrusion noted only for those with meniscal tears
• Significant decrease in contact area noted only for those with meniscal tears

BackgroundThe purpose of this study was to use MRI to determine if a loss of meniscal intra-substance integrity, as determined by T2* relaxation time, is associated with an increase of Kellgren–Lawrence (KL) grade, and if this was correlated with risk factors for cartilage degeneration, namely meniscal extrusion, contact area and anterior–posterior (AP) displacement.MethodsEleven symptomatic knees with a KL 2 to 4 and 11 control knees with a KL 0 to 1 were studied. A 3 Tesla MRI scanner was used to scan all knees at 15° of flexion. With a 222 N compression applied, a 3D SPACE sequence was obtained, followed by a spin echo 3D T2* mapping sequence. Next, an internal tibial torque of 5 Nm was added and a second 3D SPACE sequence obtained. The MRI scans were post-processed to evaluate meniscal extrusion, contact area, AP displacement and T2* relaxation time.ResultsKL grade was correlated with T2* relaxation time for both the anterior medial meniscus (r = 0.79, p < 0.001) and the posterior lateral meniscus (r = 0.55, p = 0.009). In addition, T2* relaxation time was found to be correlated with risk factors for cartilage degeneration. The largest increases in meniscal extrusion and decreases in contact area were noted for those with meniscal tears (KL 3 to 4). All patients with KL 3 to 4 indicated evidence of meniscal tears.ConclusionsThis suggests that a loss of meniscal integrity, in the form of intra-substance degeneration, is correlated with risk factors for cartilage degeneration.