Objective

The objective of our study was to assess the prevalence and evolution of intrameniscal signal-intensity alteration in subjects with an anterior cruciate ligament (ACL) tear over 24 months and compare clinical outcome and changes of cartilage between subjects with and those without this meniscal abnormality.

Materials and methods

Fifty-seven subjects with an ACL tear were screened for intrameniscal signal-intensity alteration. Morphologic and compositional MRI was performed before ACL reconstruction and 12 and 24 months after ACL reconstruction. Twelve subjects with an intrameniscal signal-intensity alteration and 12 subjects without any meniscal abnormality on MRI were identified. Clinical outcome was measured using the Knee Injury and Osteoarthritis Outcome Score (KOOS), and T1ρ and T2 maps of the cartilage were obtained.

Results

In 10 of 12 subjects (83%) the meniscal signal-intensity abnormality identified on baseline MRI was located at the posterior horn of the medial meniscus. None of these subjects presented with a meniscal tear over 24 months of follow-up. At 12 months after the ACL tear, the intrameniscal signal-intensity alteration detected on baseline MRI had completely resolved in seven of 12 subjects (58%), showed a signal-intensity decrease in four (33%), and remained stable in one subject (8%). Of the 10 subjects who underwent MRI at 24 months, the meniscal signal-intensity alteration had completely resolved in eight (80%), and the signal intensity had decreased in the other two subjects. Changes in the KOOS and cartilage T1ρ and T2 values from baseline and 24 months did not differ significantly between subjects with and those without intrameniscal signal-intensity alteration (p > 0.05).

Conclusion

High intrameniscal signal-intensity alterations are a common finding in subjects with an ACL tear and have a benign course over 24 months after surgical repair of the ACL tear.

Objectives

To assess the impact of cyclops lesions with MRI in patients treated for anterior cruciate ligament (ACL) tears on clinical outcome.

Methods

In 113 patients (age 29.8 ± 10.5y; 55 females; BMI 24.8 ± 3.7 kg/m²) with complete ACL tear, 3 T-MRI scans were obtained before, 6-months, 1-year (n = 75) and 2-years (n = 33) after ACL reconstruction. Presence and volume of cyclops lesions were assessed. Clinical outcomes were measured using the Knee injury and Osteoarthritis Outcome Score (KOOS) and differences between time points (∆KOOS) were calculated. Changes of KOOS subscales were compared between patients with and without cyclops lesion. KOOS was also correlated with lesion volume.

Results

Cyclops lesions were found in 25% (28/113), 27% (20/75) and 33% (11/33) of patients after 6-months, 1- and 2-years, respectively. The lesion volume did not change significantly (P > 0.05) between time points, measuring 0.65 ± 0.59, 0.81 ± 0.70 and 0.72.9 ± 0.96 cm³, respectively. Clinical outcomes based on KOOS subscales were not significantly different in patients with cyclops lesions compared to those without cyclops lesions (each comparison P > 0.05), and no significant associations of clinical outcomes with lesion volume were found (P > 0.05).

Conclusions

Neither presence nor size of cyclops lesions within the first 2-years after ACL surgery were associated with inferior clinical outcome.

Key points

• Cyclops lesions had a prevalence of 25% in patients after ACL reconstruction. • Subjects with cyclops lesions did not have an inferior clinical outcome. • Cyclops lesions developed within the first 6 months after surgery. • The size of cyclops lesions did not significantly change over a period of 2 years.