Do cartilage repair procedures prevent degenerative meniscus changes?: longitudinal t1ρ and morphological evaluation with 3.0-T MRI.

BACKGROUND

Cartilage repair (CR) procedures are widely accepted for treatment of isolated cartilage defects in the knee joint. However, it is not well known whether these procedures prevent degenerative joint disease.

HYPOTHESIS: Cartilage repair procedures prevent accelerated qualitative and quantitative progression of meniscus degeneration in individuals with focal cartilage defects.

STUDY

DESIGN

Cohort study; Level of evidence, 2.

METHODS

Ninety-four subjects were studied. Cartilage repair procedures were performed on 34 patients (osteochondral transplantation, n = 16; microfracture, n = 18); 34 controls were matched. An additional 13 patients received CR and anterior cruciate ligament (ACL) reconstruction (CR&ACL), and 13 patients received only ACL reconstruction. Magnetic resonance imaging at 3.0-tesla with T(1ρ) mapping and sagittal fat-saturated intermediate-weighted fast spin echo (FSE) sequences was performed to quantitatively and qualitatively analyze menisci (Whole-Organ Magnetic Resonance Imaging Score [WORMS] assessment). Patients in the CR and CR&ACL groups were examined 4 months (n = 34; n = 13), 1 year (n = 21; n = 8), and 2 years (n = 9; n = 5) after CR. Control subjects were scanned at baseline and after 1 and 2 years, ACL patients after 1 and 2 years.

RESULTS

At baseline, global meniscus T(1ρ) values (mean ± SEM) were higher in individuals with CR (14.2 ± 0.5 ms; P = .004) and in individuals with CR&ACL (17.1 ± 0.9 ms; P < .001) when compared with controls (12.8 ± 0.6 ms). After 2 years, there was a statistical difference between T(1ρ) at the overlying meniscus above cartilage defects (16.4 ± 1.0 ms) and T(1ρ) of the subgroup of control knees without cartilage defects (12.1 ± 0.8 ms; P < .001) and a statistical trend to the CR group (13.3 ± 1.0 ms; P = .09). At baseline, 35% of subjects with CR showed morphological meniscus tears at the overlying meniscus; 10% of CR subjects showed an increase in the WORMS meniscus score within the first year, and none progressed in the second year. Control subjects with (without) cartilage defects showed meniscus tears in 30% (5%) at baseline; 38% (19%) increased within the first year, and 15% (10%) within the second year.

CONCLUSION

This study demonstrated more severe meniscus degeneration after CR surgery compared with controls. However, progression of T(1ρ) values was not observed from 1 to 2 years after surgery. These results suggest that CR may prevent degenerative meniscus changes.