The Correlation of Knee Osteoarthritis with Lumbar Spine, Proximal Femur and Distal Radius Bone Mineral Density

Abstract

Although osteoporosis (OP) and osteoarthritis (OA) are both common conditions with high prevalence in older age group, they rarely coexist clinically. The aim of the study was to determine the possible inverse relation between osteoporosis (OP) and osteoarthritis (OA) by evaluating the association between bone mineral density (BMD) and knee OA. BMD’s in proximal femur, lumbar spine and distal radius were measured by LUNAR-DEXA. Knee OA was assessed by a weight bearing anteroposterior radiograph and graded on a severity scale of 4 according to Kellgren-Lawrence. We compared the bone densities of each OA group with those without knee OA. 220 patients who were evaluated as primary OA and had no history or physical examination findings suggesting secondary OA were included in the study. The mean age was 64 years and the mean weight of the patients was 78 kg. Subjects that had no radyographically evident knee OA were included as the control group. There were 21 Grade 1 OA, 98 Grade 2 OA, 88 Grade 3 OA and 13 Grade 4 OA patients. Mean lumbar and femoral BMD’s of the Grade 1 and Grade 2 OA patients were %5-8 higher then those without OA (p<0,05). Lumbar and femoral BMD’s of the patients with Grade 3 and Grade 4 knee OA were also higher than the non-OA patients but the results were not statistically significant. There was no significant relation between distal radius BMD and knee OA. The results of this study support the negative correlation between OA and OP.

Keywords

• Osteoporosis
• knee osteoarthritis