***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***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 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 decreases after total knee arthroplasty and is believed to affect prosthetic fixation . Treatment with alendronate has been shown to improve short-term bone mineral density after total knee arthroplasty ; however , the long-term effects of this therapy are unknown . The purpose of this study was to evaluate the long-term effects of a six-month course of alendronate on bone mineral density after total knee arthroplasty . METHODS Sixty patients were r and omly assigned to receive either oral alendronate at a dosage of 10 mg/day for six months or no alendronate . The bone mineral density in the distal aspect of the femur and the proximal aspect of the tibia was measured preoperatively and at six , twelve , and thirty-six months after total knee arthroplasty . RESULTS Fifty-four patients ( twenty-nine in the alendronate group and twenty-five in the control group ) completed the study . The alendronate group showed significant increases in bone mineral density in the distal aspect of the femur compared with the controls at six months ( + 4.8 % and -14.2 % , respectively ; p < 0.01 ) and twelve months ( + 1.6 % and -11.5 % , respectively ; p < 0.01 ) . No significant difference in bone mineral density was detected between the groups at thirty-six months ( -3.9 % and -12.2 % , respectively ; p = 0.08 ) . Similar trends in bone mineral density changes were also observed in the proximal aspect of the tibia . CONCLUSIONS A six-month course of alendronate initially increased bone mineral density at six and twelve months after total knee arthroplasty , but no difference was noted after thirty-six months . The effect of alendronate on bone mineral density after total knee arthroplasty may be limited after discontinuation of therapy Acute periprosthetic bone loss occurs after total hip arthroplasty . Bone loss undermines the support of the implant and may contribute to prosthetic failure . At present , there is no established prophylaxis for this process . We studied the effect of a single-dose infusion of 90 mg of pamidronate on early periprosthetic bone mineral density ( BMD ) , biochemical markers of bone turnover , radiological , and clinical outcome in a 26-week , prospect i ve , r and omized , double-blinded study of 47 men and women undergoing total hip arthroplasty .  Pamidronate therapy led to a significant reduction in bone loss compared with placebo for both the proximal femur and the pelvis ( repeated measures analysis of variance [ ANOVA ] ) ; p = 0.001 and p = 0.01 , respectively ) . Pamidronate therapy was associated with suppression of all biochemical markers of bone turnover compared with placebo ( repeated measures ANOVA ; p < 0.05 for all comparisons ) , with the exception of urinary free deoxypyridinoline . Pamidronate did not interfere with the clinical improvement in symptoms after total hip arthroplasty , or radiological outcome , and was not associated with an increase in adverse events . This study provides clinical data on the efficacy and safety of bisphosphonates for the prevention of bone loss after total hip arthroplasty and supports the establishment of larger-scale clinical trials to determine the long-term clinical efficacy of this intervention using implant failure as the primary endpoint Periprosthetic  bone loss after arthroplasty may threaten prosthesis survival . The current study investigated the effect of etidronate therapy on periprosthetic , contralateral hip , and spine bone mineral density ( BMD ) in a one-year , prospect i ve , r and omized , double-blind study on 46 patients after cemented hip arthroplasty .  BMD was measured with dual-energy X-ray absorptiometry ( DXA ) . There were no significant differences between mean BMD measurements of the etidronate and placebo groups , with the exception of the mean percent change in the spine at six months and 12 months and in Gruen zone 3 at six months ; in all three cases , the etidronate group had significantly greater mean values . These findings suggest that cyclic etidronate therapy has no significant effect in suppressing periprosthetic bone loss following cemented hip arthroplasty . RésuméLa perte osseuse périprothétique après arthroplastie peut mettre en danger la survie de la prothèse . Nous avons étudié l'effet de l'étidronate sur la densité minérale ( DM ) de l'os en zone périprothétique , au niveau de la hanche opposée et du rachis . L'étude à un an , prospect i ve , r and omisée et en double-aveugle a inclue 46 malades après arthroplastie de la hanche cimentée . La DM était mesurée par absorptiométrie biphotonique ( DXA ) . En général , il n'y avait pas de différence significative entre la DM moyenne du groupe étidronate et du groupe placebo . Les seules exceptions étaient les changements en pourcentage sur le rachis après 6 et 12 mois et en Zone 3 de Gruen après 6 mois ; dans tous ces cas , le groupe étidronate avait des valeurs moyennes significativement plus gr and es . Ces résultats indiquent que la thérapie cyclique par étidronate n'a pas d'effet significatif pour enrayer la perte osseuse périprothétique après arthroplastie cimentée de la hanche Menopause and increasing age are associated with a decrease in calcium absorption that can contribute to the pathogenesis of osteoporosis . We hypothesized that alendronate plus vitamin D(3 ) ( ALN + D ) would increase fractional calcium absorption ( FCA ) . In this r and omized , double-blind , placebo-controlled multicenter clinical trial , 56 postmenopausal women with 25-hydroxyvitamin D [ 25(OH)D ] concentrations of 25 ng/mL or less and low bone mineral density ( BMD ) received 5 weekly doses of placebo or alendronate 70 mg plus vitamin D(3 ) 2800 IU ( ALN + D ) . Calcium intake was stabilized to approximately 1200 mg/d prior to r and omization . FCA was determined using a dual-tracer stable-calcium isotope method . FCA and 25(OH)D were similar between treatment groups at baseline ( 0.31 ± 0.12 ng/mL and 19.8 ± 4.7 ng/mL , respectively ) . After 1 month of treatment , subjects r and omized to ALN + D experienced a significant least squares ( LS ) mean [ 95 % confidence interval ( CI ) ] increase in FCA [ 0.070 ( 0.042 , 0.098 ) ] , whereas FCA did not change significantly in the placebo group [ -0.016 ( -0.044 , 0.012 ) ] . After ALN + D treatment , patients had higher 25(OH)D levels ( LS mean difference 7.3 ng/mL , p < .001 ) . The rise in serum 1,25-dihydroxyvitamin D(3 ) ( p < .02 ) and parathyroid hormone ( p < .001 ) were greater in the ALN + D group than in placebo-treated patients . ALN + D was associated with an increase in FCA of 0.07 . To our knowledge , there is no other trial showing such a marked rise in calcium absorption owing to treatment with a bisphosphonate or owing to a small rise in 25(OH)D. This unique response of ALN + D is important for the treatment of osteoporosis , but the exact mechanism requires further study Undesired bone loss around implants is considered to occur mainly because of a stress-shielding phenomenon . Bone surrounding the total knee arthroplasty ( TKA ) adjusts its mineral density and structure to meet new mechanical dem and s. Immobilization , in combination with local operative trauma to the bone and soft tissues , has an additional impact on bone loss . The clinical survival of TKA is associated with the quality and quantity of the surrounding bone environment . Poor bone quality and quantity may predispose to aseptic implant loosening and periprosthetic fractures . We investigated the 
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The efficacy was more potent for the second and the third generation of BPs than the first generation .
Conclusions The overall moderate evidence from the RCTs confirmed the significantly short-term and middle-term efficacy of BPs on periprosthetic bone loss after joint arthroplasty .