Patterns of pain in Paget's disease of bone and their outcomes on treatment with pamidronate.

Two-thirds of patients with Paget's disease seeking medical attention present with pain. We studied patterns of pagetic pain in relation to physical activity, and the effect of coexistent osteoarthritis (OA)/pagetic arthropathy on pain and physical activity before and after treatment with pamidronate. Patients with lower-segment Paget's disease (lumbar spine, pelvis or lower limbs), raised alkaline phosphatase (ALP), and pain as a symptom were included. Two subgroups were identified based on the absence (P group), or presence (POA group) of radiological OA in the lower segment. They received 2-4 fortnightly infusions of pamidronate 30-60 mg and were followed up at 6 weeks, 3 months and 6 months. Outcome measures were visual analog scales for pain at rest, on standing, on walking and at night; standing time, walking distance, 50-yard walking time, and ALP. Twenty-five patients (12 men, 13 women, mean age 70.1+/-1.9 years), received a mean of 142+/-9.7 mg of pamidronate. The P group had higher mean ALP (p=0.003) and higher scores for pain (not significant) at baseline than the POA group. Compared to baseline, P group had significant improvements (p<0.01) at 6 months in rest pain, standing pain and walking pain. The POA group had non-significant changes in pain at 6 months. ALP improved significantly at 6 months in both subgroups (p<0.01). The whole group also improved at 6 months in standing time (55.7%, not significant), walking distance (33.9%, not significant), and 50-yard walking time (24.2%, p<0.05). Paget's patients with coexistent joint disease had less severe pain and bone disease at baseline than those without coexistent joint disease, and responded less well to pamidronate, although they did have significant improvement in ALP levels. Radiographic assessment for coexisting joint disease prior to treatment might improve prognostication from the patient's point of view, and improve treatment compliance.