Natural history and clinical significance of MRI-detected bone marrow lesions at the knee: a prospective study in community dwelling older adults

Dawn Dore,Graeme Jones,Flavia Cicuttini,Guangju Zhai,Stephen Quinn,Tania Winzenberg,Changhai Ding

doi:10.1186/ar3210

Abstract

IntroductionThere are conflicting data on the natural history and clinical significance of bone marrow lesions (BMLs). The aims of this study were to describe the natural history of MRI-detected BMLs at the knee using a quantitative measure and examine the association of BMLs with pain, function and stiffness scores, and total knee replacement (TKR) surgery.MethodsA total of 395 older males and females were randomly selected from the general population (mean age 63 years, range 52 to 79) and measured at baseline and approximately 2.7 years later. BMLs were determined using T2-weighted fat saturation MRI by measuring the maximum area of the lesion. Reproducibility was excellent (intraclass correlation coefficient (ICC): 0.97). Pain, function, and stiffness were assessed by Western Ontario and McMaster Universities Osteoarthritis (WOMAC) scores. X-ray was used to assess radiographic osteoarthritis (ROA) at baseline.ResultsAt baseline, 43% (n = 168/395) had a BML. Of these 25% decreased in size and 24% increased. Of the remaining sample (n = 227), 7% developed a new BML. In a multivariable model, a change in BML size was associated with a change in pain and function scores (β = 1.13 to 2.55 per 1 SD increase, all P < 0.05), only in those participants without ROA. Lastly, baseline BML severity predicted TKR surgery (odds ratio (OR) 2.10/unit, P = 0.019).ConclusionsIn a population based sample, BMLs (assessed by measuring maximal area) were not static, with similar proportions both worsening and improving. A change in BML size was associated with changes in pain in those without established ROA. This finding suggests that fluctuating knee pain may be attributable to BMLs in those participants with early stage disease. Baseline BMLs also predicted TKR surgery. These findings suggest therapeutic interventions aimed at altering the natural history of BMLs should be considered.

Highlights

There are conflicting data on the natural history and clinical significance of bone marrow lesions (BMLs)
There were no significant differences in demographics, radiographic osteoarthritis (ROA), Western Ontario and McMaster Universities Osteoarthritis (WOMAC) function or stiffness scores, Assessment of Quality of Life (AQoL) scores, or leg strength between the rest of the cohort (n = 704) and the subjects included in the current study (n = 395)
A change in BML size was associated with changes in pain as assessed by WOMAC scores, only in those without ROA, even after adjustment for a large number of factors that have been linked to knee pain [39]

Summary

Introduction

There are conflicting data on the natural history and clinical significance of bone marrow lesions (BMLs). We have shown that elevated tibial bone area and subchondral bone mineral density (BMD) predicted cartilage defect increases [2]. Tibial bone area predicted cartilage volume loss. Bone marrow lesions (BMLs) have been recognized as an important feature of knee OA [3,4]. They are associated with structural changes in the knee, including joint space loss on radiographs [4], cartilage defect progression [5] and cartilage loss on MR images [5,6,7].

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