Signs & Symptoms of Bone Disease in Chronic Kidney Disease

People diagnosed with chronic kidney failure (CKF) are likely to suffer from a hidden bone disease called renal osteodystrophy. This metabolic bone disease afflicts more than 90 percent of those receiving dialysis and can lead to bone fractures and deformities. The cause lies in the kidney's inability to monitor calcium and phosphorus levels in the blood and convert vitamin D to its active form which is necessary for the absorption of calcium. Although common in the later stages of CKF, it is often dubbed the "silent crippler" because signs and symptoms of metabolic bone disease can appear months or years prior to a kidney failure diagnosis, according to the National Institute of Diabetes and Digestive Kidney Diseases (NIDDK).

Weak, Painful Bones

• People with this disease have fragile bones which are prone to spontaneous fractures--particularly in the ribs, pelvis and hips. Patients often complain of a dull, aching pain in the lower spine and in the long bones of the arms and legs. The pain is usually made worse by movement. It may come on gradually or in sudden waves following a fracture.

Bone Deformities

• Adults with renal osteodystrophy often show an abnormal curvature of the spine. Children with the bone disease are typically shorter than normal with legs that are bent inwardly or bowed outwardly toward each other in an abnormal way. This condition is referred to as "renal rickets" and is often the first sign leading to a chronic kidney failure diagnosis.

Joint and Muscle Pain

• Other symptoms reported include pain and stiffness in the joints of the lower limbs. Muscle weakness and occasional numbness in the legs is a common symptom. In severe cases, some people may develop ruptured tendons.

Difficulty Moving

• Weakened and deformed bones as well as decreased muscle tone make moving difficult. A "waddling" like gait is often associated in people who have this disease.

Abnormal Lab Findings

• To help rule out other bone diseases and support a diagnosis of metabolic bone disease, your doctor may run a laboratory panel to measure the amounts of certain minerals and hormones in your blood. Those with the disease may show signs of increased levels of parathyroid hormone (PTH) and phosphorus and lower than normal levels of calcium. When blood calcium levels fall, PTH goes into overdrive causing even more calcium from the bone to drain into the blood. A decline in calcium causes an increase in phosphorus. A weakened kidney cannot produce calcitriol -- the hormone that activates Vitamin D - so lower than normal levels of calcitriol is also typical in a positive diagnosis.