Evaluation of Meniscal Tissue after Meniscal Repair Using Ultrahigh Field MRI.

The study evaluates the meniscal tissue after primary meniscal suturing using 7-Tesla (T) magnetic resonance imaging with T2* mapping at 6 and 12 months after surgery to investigate the differences between repaired meniscal tissue and healthy meniscal tissue in the medial and lateral compartment. This prospective study included 11 patients (9m/2f) with a mean age of 30.6 years (standard deviation 9.0). Patients with a meniscal tear that was treated arthroscopically with meniscus suturing, using an all-inside technique, were included. All patients and seven healthy volunteers were imaged on a 7-T whole-body system. T2* mapping of the meniscus was applied on sagittal slices. Regions-of-interest were defined manually in the red and white zone of each medial and lateral meniscus to measure T2*-values. In the medial posterior and medial anterior horn similar T2*-values were measured in the red and white zone at 6- and 12-month follow-up. Compared with the control group higher T2*-values were found in the repaired medial meniscus. After 12-months T2*-values decreased to normal values in the anterior horn and remained elevated in the posterior horn. In the red zone of the lateral posterior horn a significant decrease in the T2*-values (from 8.2 milliseconds to 5.9 milliseconds) (p = 0.04), indicates successful repair; a tendency toward a decrease in the white zone between the 6 and 12 months follow-up was observed. In the red zone of the lateral anterior horn the T2*-values decreased significantly during follow-up and in the white zone of the lateral anterior horn T2*-values were comparable. In comparison to the control group higher T2*-values were measured at 6-months; however, the T2*-values showed comparable values in the repaired lateral meniscus after 12 months. The T2* mapping results of the current study indicated a better healing response of the red zone of the lateral posterior horn compared with the medial posterior horn.