Background: To describe the clinical and laboratory features of Paget's disease of bone at the time of diagnosis.
Patients and method: This multicenter and retrospective study included 314 patients. Diagnosis was performed by means of characteristic radiological findings and typical bone scintigraphy. The variables analyzed included: epidemiological variables, cause of diagnosis, bone involvement, disease extension (Coutris index), complications, alkaline phosphate (AP) levels and disease activity (Renier index).
Results: There were 159 (50.5%) males and the mean age was 64.9 years (SD 12.6). Diagnosis was casual in 228 (72.6%) patients. Polyostotic involvement was detected in 201 (63.9%) patients. More common locations were pelvis, skull and lumbar spine. Sacrum was more frequently involved in men than in women (p < 0.05), whereas skull involvement was more common in women (p < 0.05). The number of bones involved was 3.1 SD 3 and the percentage of skeletal involvement was 8.7 % (SD 6.5). One hundred ninety eigth (63%) patients had complications. The disease was active in 242 (77%) patients with a mean AP value of 377 IU/L (SD 493); the activity of the disease measured by the Renier index was 34 (SD 46); the activity was greater in the skull and the humerus.
Conclusions: Paget's disease of bone is usually asymptomatic. Polyostotic involvement and activity are common at the time of diagnosis. Knowledge of the extension and activity by means of a mathematical model may aid to make therapeutical decisions.