Knee pain spreading to the back may sometimes be due to joint strain or an underlying spine or posture-related issue rather than uric acid or calcium alone. Since etodolac is only providing slight relief, you should have a medical review of your knee and lower back and consider imaging, such as an X-ray or MRI, if advised. A calcium level of 8.4 is borderline low, so your doctor may reassess your nutrition, vitamin D status, and supplementation. Along with medicines, regular physiotherapy and gentle strengthening exercises are often important for long-term improvement.