***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: 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 r and omized 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 c and i date s for prevention strategies Summary Forty-three patients who had undergone cementless THA were r and omly assigned to receive no osteoactive drug or oral risedronate for 6 months . Postoperative decrease of BMD in the risedronate group was significantly lower than that seen in the control group in zones 1 , 2 , 3 , 6 , and 7 . Introduction Proximal bone resorption around the femoral stem often has been observed after total hip arthroplasty ( THA ) , could lead to late stem loosening . We previously reported the efficacy of etidronate on periprosthetic bone resorption after cementless THA . Recently risedronate is suggested to be effective for the prevention and treatment of for osteoporosis . The purpose of the present study was to evaluate the effects of risedronate on periprosthetic bone loss after cementless THA . Methods Forty-three patients who had undergone cementless THA were r and omly assigned to receive no osteoactive drug  ( 21 patients ) or oral risedronate 2.5 mg/day ( 22 patients ) for 6 months . Three patients were eliminated from the risedronate group because of dyspepsia . Periprosthetic bone mineral density ( BMD ) in seven regions of interest based on the zones of Gruen et al. was measured with dual energy X-ray absorptiometry at 3 weeks and 6 months postoperatively . Results At 6 months after surgery , postoperative decrease of BMD in the risedronate group was significantly lower than that seen in the control group in zones 1 , 2 , 3 , 6 , and 7 ( p < 0.05 , p < 0.01 , p < 0.01 , p < 0.05 , and p < 0.05 , respectively ) . Conclusion These outcomes suggested that risedronate might reduce the periprosthetic bone resorption after cementless THA This r and omized trial evaluated the effect of zoledronic acid on  femoral bone mineral density ( BMD ) following primary total hip arthroplasty .  Bone mineral density was compared for up to 2years in 27 patients receiving 5 mg zoledronic acid intravenous infusion and in 24 patients receiving placebo  at 2weeks and 1year after surgery . Zoledronic acid prevented loss of bone mineral density at 1year ( + 13.8 % vs + 1.4 % , P=.0065 ) and 2years ( + 14.3 % vs -4.0 % , P<.0001 ) in Gruen zone 1 , at 1year ( -8.4 % vs -25.4 % , P<.0001 ) and 2years ( -9.6 % vs -27.3 % , P<.0001 ) in Gruen zone 7 , at 6weeks , 6months , and 1 or 2years in Gruen zones 4 and 6 . For all Gruen zones , prevention of BMD loss by ZOL was significant at 6weeks , 6months , 1year ( + 0.80 % vs -6.03 % , P<.0001 ) and 2years ( -0.16 % vs -7.13 % , P<.0001 ) Background and Aims : Periprosthetic bone loss , especially in the proximal part of the femur , is common after cemented and uncemented total hip arthroplasty ( THA ) . Short-term studies suggest that bisphosponates can minimize this bone loss related to stress-shielding phenomenon . The aim of the present r and omized study was to investigate whether the positive effect of a 6 months alendronate treatment postoperatively still exists at five-year follow up . Material s and Methods : Sixteen uncemented primary THA patients were r and omized to receive either 10 mg alendronate + 500 mg calcium ( n = 7 ) or 500 mg calcium only ( n = 9 ) daily for 6 months postoperatively . Periprosthetic bone mineral density ( BMD ) was measured with the dual X-ray absorptiometry ( DXA ) postoperatively and at 6 , 12 , 24 , 36 and 60 months follow-up . Results : At the 5-year follow up , the calcium group showed mean BMD decreases of 23.1 % ( SD 14.6 ) in the proximal part of the femur ( prROI ) and 9.6 % ( SD 14.9 ) in total femoral regions of interest ( totROI ) . In the alendronate group the corresponding BMD decreases were 13.6 % ( SD 19.0 ) and 3.9 % ( SD 7.6 ) respectively . The positive effect of alendronate was already demonstrated during the first six months postoperatively . Subsequently the bone loss was equal in both groups , and the 5-year BMD changes were not significantly different between the groups . Conclusions : Alendronate seems to decrease early periprosthetic bone loss after arthroplasty but this pilot study could not provide enough evidence that the positive effect noted in the early postoperative period is still maintained 5 years after the operation BACKGROUND Bone mineral density ( BMD ) loss around femoral implants , particularly in the proximal femur , is a common outcome after total hip arthroplasty . Previous studies reported the prevention of postsurgical decrease in BMD with the use of osteoporosis drug therapy . This r and omized study evaluated the efficacy of alendronate and alfacalcidol for preserving BMD over a long-term follow-up . METHODS Sixty consecutive patients with hip osteoarthritis who had undergone primary cementless total hip arthroplasty were r and omly assigned to an alendronate ( n = 20 ) , alfacalcidol ( n = 18 ) , or control ( n = 22 ) group . Periprosthetic BMD was measured using dual-energy X-ray absorptiometry at 1 week , 1 year , and the current follow-up ( minimum 9 years after surgery ) . Changes in BMD are reported as mean percentages relative to the values at 1 week ( baseline reference ) . RESULTS All groups showed a significant decrease in the BMD of the calcar at the current follow-up compared to the values at both 1 week and 1 year postoperatively ( P < .001 ) . The BMD values were significantly higher in the alendronate group than in the alfacalcidol and control groups ( P < .05 ) . The BMD values at the current follow-up were 76 % ± 30 % ( alendronate group ) , 64 % ± 22 % ( alfacalcidol group ) , and 59 % ± 22 % ( control group ) of the baseline values . CONCLUSION Our findings demonstrate the efficacy of early administration of alendronate for the prevention of bone loss in the calcar region In this study the efficacy of an oral bisphosphonate therapy to inhibit wear debris mediated bone resorption was evaluated in a canine total hip replacement model . Adult canines were r and omized to three groups ( n = 8 each ) with a right uncemented total hip replacement performed on each animal . Group I ( control ) received no particulate debris . In Groups II and III , a mixture of 1 x 10(9 ) particles were introduced into the proximal femoral gap intraoperatively . The particle mixture consisted of fabricated ultra high molecular weight polyethylene ( mean 2.3 microns , 90 % by number ) , titanium alloy ( mean 3.1 microns , 5 % ) , and cobalt chrome alloy ( mean 0.8 micron , 5 % ) . Group III canines additionally received oral drug therapy ( 5 mg once a day , alendronate sodium ) which was begun on postoperative Day 7 and continued until the time of sacrifice . Postoperatively , all animals were allowed 24 weeks of full ambulation before euthanasia . Radiographs obtained preoperatively , postoperatively , and at time of sacrifice were evaluated for periprosthetic osteolysis . Interfacial tissues were examined histologically and placed in organ culture and the supernatants were assayed for prostagl and in E2 and interleukin-1 . One animal receiving debris ( Group II ) suffered a periprosthetic fracture and was sacrificed from the study . Radiographically , one of eight Group I ( control ) and six of seven canines from Group II ( debris ) had periprosthetic radiolucencies with endosteal scalloping develop . In contrast , only one of eight animals from Group III ( debris + alendronate ) had periprosthetic radiolucencies develop . Whereas tissues from control animals were mostly fibrous and acellular , tissues from both experimental groups had significant macrophage infiltration . Levels of prostagl and in E2 and interleukin-1 were elevated significantly in periprosthetic tissues from both experimental groups compared with controls . Continuous administration of alendronate effectively inhibited bone lysis for the 24-week duration of the study . This is consistent with the literature indicating that alendronate is incorporated in the mineralizing matrix making it refractory to osteoclastic resorption . This report has significant clinical implication s for controlling the most common cause of implant failure Background and purpose — We have previously shown that during the first 2 years after total hip arthroplasty ( THA ) , periprosthetic bone resorption can be prevented by 6 months of risedronate therapy . This follow-up study investigated this effect at 4 years . Patients and methods — A single-center , double-blind , r and omized placebo-controlled trial was carried out from 2006 to 2010 in 73 patients with osteoarthritis of the hip who were scheduled to undergo THA . The patients were r and omly assigned to receive either 35 mg risedronate or placebo orally , once a week , for 6 months postoperatively . The primary outcome was the percentage change in bone mineral density ( BMD ) in Gruen zones 1 and 7 in the proximal part of the femur at follow-up . Secondary outcomes included migration of the femoral stem and clinical outcome scores . Results — 61 of the 73 patients participated in this 4-year ( 3.9- to 4.1-year ) follow-up study . BMD was similar in the risedronate group ( n = 30 ) and the placebo group ( n = 31 ) . The mean difference was −1.8 % in zone 1 and 0.5 % in zone 7 . Migration of the femoral stem , the clinical outcome , and the frequency of adverse events were similar in the 2 groups . Interpretation — Although risedronate prevents periprosthetic bone loss postoperatively , a decrease in periprosthetic BMD accelerates when therapy is discontinued , and no effect is seen at 4 years . We do not recommend the use of risedronate following THA for osteoarthritis of the hip BACKGROUND Antiresorptive agents are widely used to treat osteoporosis . We report the results of a multinational r and omized , double-blind study , in which postmenopausal women with osteoporosis were treated with alendronate for up to 10 years . METHODS The initial three-year phase of the study compared three daily doses of alendronate with placebo . Women in the original placebo group received alendronate in years 4 and 5 and then were discharged . Women in the original active-treatment groups continued to receive alendronate during the initial extension ( years 4 and 5 ) . In two further extensions ( years 6 and 7 , and 8 through 10 ) , women who had received 5 mg or 10 mg of alendronate daily continued on the same treatment . Women in the discontinuation group received 20 mg of alendronate daily for two years and 5 mg daily in years 3 , 4 , and 5 , followed by five years of placebo . R and omized group assignments and blinding were maintained throughout the 10 years . We report results for the 247 women who participated in all four phases of the study . RESULTS Treatment with 10 mg of alendronate daily for 10 years produced mean increases in bone mineral density of 13.7 percent at the lumbar spine 
    Output:
    
Conclusion BPs were beneficial to decreasing periprosthetic bone loss .
The third-generation BPs showed significantly efficacy for patients in short-term observation