Decreased periprosthetic bone loss in patients treated with clodronate: a 1-year randomized controlled study.

The efficacy of clodronate to reduce bone loss around uncemented stems after total hip arthroplasty(THA) was evaluated. Ninety-one patients operated with uncemented THA were randomized to receive either intramuscular clodronate at a dose of 100 mg weekly for 12 months or no treatment. Periprosthetic and contralateral bone mineral density (BMD) scans were performed and biochemical markers of bone turnover measured at baseline and at 3, 6, and 12 months. At month 12, with the exception of Gruen zones 4 and 5, patients treated with clodronate showed less bone loss at all zones, reaching statistical significance (P\0.05) in Gruen zones 2 and 6 (difference of 6.6 and 5.9%, respectively). Analysis of data according to gender revealed sex-related differences in bone loss and efficacy of treatment. After 12 months, the difference in bone loss between treated and untreated women in five out of seven Gruen zones ranged from 6.2 to 13.3% (SS at zones 2 and 6), whereas comparison between treated and untreated men showed no BMD differences in all zones(P[0.05). Median percent changes in serum levels of markers of bone metabolism by gender were consistent with BMD changes. A 1-year treatment with intramuscular clodronate determined a significant reduction of bone loss after THA. This was mainly attributed to its greater efficacy in the female population, which is at higher risk for bone loss. This observation suggests the need for the characterization of high-risk subjects as potential candidates for prevention strategies.