The interactions between MRI-detected osteophytes and bone marrow lesions or effusion-synovitis on knee symptom progression: an exploratory study

OBJECTIVES

To investigate the longitudinal association between MRI-detected osteophyte scores and progression of knee symptoms, and whether the association was modified in the presence of bone marrow lesions (BMLs) or effusion-synovitis.

METHODS

Data from Vitamin D Effects on Osteoarthritis (VIDEO) study, a randomized, double-blinded and placebo-controlled clinical trial in symptomatic knee osteoarthritis (OA) patients, were analyzed as an exploratory study. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to assess knee symptoms. Osteophytes, BMLs and effusion-synovitis were measured using MRI.

RESULTS

334 participants with MRI information and WOMAC score (baseline and follow-up) were included in the analyses, with 24.3% of them having knee pain increased 2 years later. Statistically significant interactions were found between MRI-detected osteophytes and BMLs or effusion-synovitis on increased knee symptoms. In participants with BMLs, higher baseline scores of MRI-detected osteophytes in most compartments were significantly associated with increased total knee pain, weight-bearing pain, stiffness, and physical dysfunction, after adjustment for age, sex, body mass index, intervention and effusion-synovitis. In participants with effusion-synovitis, higher baseline scores of MRI-detected osteophytes in almost all the compartments were significantly associated with increased total knee pain, weight-bearing pain, stiffness, and physical dysfunction, after adjustment for age, sex, body mass index, intervention and BMLs. In contrast, MRI-detected osteophyte scores were generally not associated with knee symptom progression in participants without baseline BMLs or effusion-synovitis.

CONCLUSIONS

MRI-detected OPs are associated with increased total knee pain, weight-bearing knee pain, stiffness and physical dysfunction in participants presenting BMLs or effusion-synovitis, but not in participants lacking BMLs or effusion-synovitis. This suggests they could interact with bone or synovial abnormalities to induce symptoms in knee OA.

Associations between MRI-detected early osteophytes and knee structure in older adults: a population-based cohort study

OBJECTIVES

To describe prevalence of osteophytes (OPs) detected only by magnetic resonance imaging (MRI) but not by standard X-ray in older adults and to evaluate longitudinal associations with knee structural changes.

METHODS

837 participants were randomly selected from the local community and had MRI scans to assess knee OPs and other structures. OPs detected only by MRI but not by standard X-ray were defined as MRI-detected early OPs (MRI-OPs for short). OPs detected by both MRI and X-ray were defined as established-OPs.

RESULTS

The prevalence of MRI-OPs was 50% while the prevalence of established-OPs was 10% and no-OPs was 40% at total tibiofemoral (TF) compartment at baseline. Compared with no-OPs, participants with MRI-OPs had greater risks of increased cartilage defects in all TF compartments (RR 1.37, 95%CI 1.07-1.74) and bone marrow lesions (BMLs) only in medial TF compartment (RR 1.49, 95%CI 1.06-2.11), after adjustment for age, sex, BMI, cartilage defects, BMLs and/or joint space narrowing; participants with established-OPs had greater cartilage volume loss at total (β -2.02, 95%CI -3.86, -0.17) and lateral tibial sites (β -5.63, 95%CI -9.93, -1.32), greater risks of increased cartilage defects in total (RR 1.66, 95%CI 1.15-2.40) and medial TF compartments (RR 1.49, 95%CI 1.20-1.69) and BMLs in all TF compartments (RR 1.88, 95%CI 1.22-2.89), after adjustment for covariates.

CONCLUSION

MRI-OPs were associated with changes in knee structures, and the associations were similar but not as prominent as those for established-OPs. These suggest MRI-OPs may have a role to play in knee early-stage osteoarthritic progression.

Association between MRI-detected osteophytes and changes in knee structures and pain in older adults: a cohort study

OBJECTIVE

To describe cross-sectional and longitudinal associations between magnetic resonance imaging (MRI)-detected osteophytes (OPs) and knee structural abnormalities and knee pain in older adults.

METHOD

A prospective population-based cohort study of 895 participants aged 50-80 years (mean age 62 years, 50% female) was performed. T1-or T2-weighted fat suppressed MRI was used to assess knee OPs, cartilage volume, cartilage defects and bone marrow lesions (BMLs) at baseline and after 2.6 years. Radiographically-detected OPs were scored according to the Osteoarthritis Research Society International (OARSI) atlas. Knee pain was assessed using a self-administered questionnaire at baseline, 2.6 and 5 years later.

RESULTS

85% of participants had MRI-detected OPs at baseline, while 10% of participants had radiographically-detected OPs. Cross-sectionally, higher gardes of MRI-detected OPs in all compartments were significantly, independently and site-specifically associated with higher prevalences of cartilage defects and BMLs, lower cartilage volume and higher prevalence of knee pain. Longitudinally, higher gardes of baseline MRI-detected OPs site-specifically predicted greater risks of any increase in cartilage defects or BMLs, and loss of cartilage volume in medial and lateral tibiofemoral (LTF) and total compartments over 2.6 years in multivariable analyses. These significant associations were similar in those without radiographically-detected OPs. MTF and total OP scores were significantly associated with change in total knee pain over 2.6 and 5 years but these became non-significant after adjustment for cartilage defects and BMLs.

CONCLUSION

MRI-detected knee OPs are common and appear to be clinically relevant to knee structural changes in older adults.