Summary

Patients with presence of bone marrow lesions in the medial compartment one year after anterior cruciate ligament (ACL) trauma and patients with progression of cartilage defects in the tibiofemoral compartment have lower subjective outcome scores two years after ACL rupture.

Abstract

Introduction

A long-term consequence of an ACL rupture is the development of osteoarthritis (OA). For an adequate treatment strategy after ACL rupture it is important to identify those patients at risk for OA development. Early degenerative changes can be assessed on MRI. However, it is also important to evaluate the relationship between MRI findings and subjective outcome. The aim of this study is to assess whether MRI findings predict subjective clinical outcome two years after ACL rupture.

Methods

In this observational prospective follow-up study 154 eligible patients were included within 6 months after ACL trauma and followed for two years. Patients were treated operatively or non-operatively and were evaluated at baseline, one year and two years follow-up. For analyses of subjective outcomes two years after ACL rupture the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales Symptoms, Sport and Recreation and knee-related Quality of Life (QoL) and the International Knee Documentation Committee Subjective Knee Form (IKDC subjective) were used. MRI scans were assessed according to a semi-quantitative MRI score. The following MRI findings were analyzed as independent variables: presence of meniscal tear and cartilage defect at baseline, presence of bone marrow lesions (BMLs) one year after ACL trauma, progression of cartilage defects and osteophytes during two-year follow-up.

Results

Of 143 patients MRI data were available of two-year follow-up. The study population had the following baseline characteristics: median age 25.2 (interquartile range (IQR) 21.4 - 32.6) years; 34 % female; median Tegner activity score pre-trauma 9 (IQR 7 - 9), 85 % scored =2+ on Lachman test. Two years after ACL rupture patients had high subjective outcome scores excluding knee related quality of life: KOOS symptoms, median 92.9 (IQR 80.4 – 100.0), KOOS sport & Recreation, median 85.0 (IQR 65.0 – 100.0), IKDC subjective, median 89.7 (IQR, 80.5 – 96.0) and KOOS QoL 75.0 (IQR 62.5 – 87.5). Patients with presence of BMLs in the medial tibiofemoral compartment one year after ACL rupture had lower subjective scores at two year follow-up compared to patients without BMLs: IKDC subjective (median score 77.0 versus 90.8; p=0.021), KOOS symptoms (median score 85.7 versus 92.9; p=0.007) and KOOS Sport and Recreation (median score 80.0 versus 90.0; p=0.001). Patients with progression of cartilage defects in the tibiofemoral compartment two years after ACL rupture showed significant lower subjective scores than patients without progression on KOOS symptoms (median score 85.7 versus 92.9; p=0.001) and KOOS QoL (median score 68.8 versus 75.0; p=0.007). Presence of the other MRI findings had no significant relationship with the subjective outcome scores.

Conclusion

Patients had high subjective outcome scores two years after ACL rupture. Patients with presence of BMLs in the medial compartment one year after trauma and patients with progression of cartilage defects in the tibiofemoral compartment have lower subjective outcome scores two years after ACL rupture.