ABSTRACT # 742 - The effect of meniscal damage on incident radiographic knee osteoarthritis
Authors
M Englund, A Guermazi, FW Roemer, M Yang, CE Lewis, J Torner, M Nevitt, DT Felson.
Background
Joint injury is known to be a predictor of future osteoarthritis. In the present report, the authors focus specifically on the relationship of meniscal damage, in the absence of surgical intervention, on the development of radiographic osteoarthritis in the affected knee.
Methods
The authors examined the relation of meniscal damage, at baseline, to incident radiographic evidence of knee osteoarthritis during 30 months of follow-up utilizing the 3026 members of the prospective Multicenter Osteoarthritis Study. Weight-bearing x-rays were taken at baseline and at the end of follow-up period. Importantly, the radiographic assessment of osteoarthritis was blind as to meniscal damage status. In this nested case-control study there were 52 cases without radiographic evidence of osteoarthritis at baseline who developed incident radiographic OA and 130 controls who were similar at baseline but did not develop osteoarthritis during the follow-up period. Exposure status was assessed by MRI imaging at baseline.
Results
Interestingly, half of the cases had MRI evidence of meniscal damage compared to only 18% of the controls. Moreover, MRI evidence of any meniscal damage (an exposure measure which aggregated minor tear, non-displayed as well as displaced tears, maceration or destruction) was associated with a 6-fold greater risk of radiographic osteoarthritis at the tibiofemoral compartment [odds ratio 6.4; 95% confidence interval 2.8 – 14.9]. Of note, the analyses were adjusted age, gender, body mass index, physical activity and knee alignment.
Conclusions
The authors conclude that meniscal damage has a clear relationship to incident knee osteoarthritis and is a strong predictor for the subsequent development of this disorder.
Editorial Comment
Whereas antecedent knee injury is known to be related to an increase in incidence of future knee osteoarthritis, there is uncertainty and debate as to whether this excess risk is attributable to the knee injury itself (to the meniscus or ligament) or a consequence of the intervention orthopedic surgery (be it arthroscopic or open) .
The study design is particularly informative at sorting out the contribution of meniscal injury, from the potential long-term deleterious effect of meniscectomy surgery (notwithstanding the short-term therapeutic benefit) on incident osteoarthritis. This design gain however is predicated on the accuracy of negative responses, by the study participants, of prior self-reported knee surgery.
A major strength of the study design was the use of MRI imaging to ascertain meniscal damage at baseline. Whereas physical examination may be of questionable sensitivity and specificity in this determination, as would patient self-report likely be as well, MRI is an objective and sensitive screening test of meniscal status.
It would be of interest to know at what stage in their lives the meniscal injury had occurred. It is conceivable that greater lifetime cumulative exposure to knee injury (such as might occur during athletic activities during adolescence, teenage years and young adult life, might impart a greater lifetime risk of future knee osteoarthritis, than injuries sustained later in life.
