Effect of etidronate in preventing periprosthetic bone loss following cemented hip arthroplasty: A randomized, double blind, controlled trial

Comparing the Efficacy of Antiosteoporotic Drugs in Preventing Periprosthetic Bone Loss Following Total Hip Arthroplasty: A Systematic Review and Bayesian Network Meta-Analysis

BACKGROUND

Periprosthetic bone loss is a well-known phenomenon following total hip arthroplasty (THA). However, the choice of drugs for prevention remains controversial. Therefore, the aim of this study was to determine the best drug to treat periprosthetic bone loss by comparing changes in bone mineral density (BMD) at different times after THA.

METHODS

A comprehensive search of five databases and two clinical trial registration platforms was undertaken from their inception through to August 31, 2023 to identify eligible randomized controlled trials. A Bayesian network meta-analysis (NMA) was carried out for calculating the standardized mean difference (SMD) and the surface under cumulative ranking curve (SUCRA) of the BMD in calcar (Gruen zone 7) at 6 months, 12 months, and 24 months and over.

RESULTS

Twenty-nine trials involving 1427 patients and 10 different interventions were included. The results demonstrated that at 6 months, denosumab had the highest ranking (SUCRA = 0.90), followed by alendronate (SUCRA = 0.76), and zoledronate (SUCRA = 0.73). At 12 months, clodronate ranked highest (SUCRA = 0.96), followed by denosumab (SUCRA = 0.84) and teriparatide (SUCRA = 0.82). For interventions with a duration of 24 months and over, denosumab had the highest SUCRA value (SUCRA = 0.96), followed by raloxifene (SUCRA = 0.90) and zoledronate (SUCRA = 0.75).

CONCLUSION

Investigating the existing body of evidence revealed that denosumab demonstrates potential as an intervention of superior efficacy at the three specifically examined time points. However, it remains crucial to conduct further research to confirm these findings and determine the most effective treatment strategy.

Anti-osteoporotic drug efficacy for periprosthetic bone loss after total hip arthroplasty: A systematic review and network meta-analysis

BACKGROUND

Periprosthetic bone loss following total hip arthroplasty (THA) threatens prosthesis stability. This systematic review and network meta-analysis aimed to compare the efficacy of anti-osteoporotic drugs for measures of hip function according to functional outcomes, periprosthetic femoral bone mineral density loss in each Gruen zone, and revision surgery after THA.

METHODS

The systematic search of six literature databases was conducted in December 2021 in accordance with PRISMA guidelines. Adult participants who underwent primary THA were included. A random-effects network meta-analysis was performed within a frequentist framework, and the confidence in the evidence for each outcome was evaluated using the CINeMA tool, which assessed the credibility of results from the network meta-analysis. We included 22 randomized controlled trials (1243 participants) comparing the efficacy and safety of bisphosphonates (including etidronate, clodronate, alendronate, risedronate, pamidronate, and zoledronate), denosumab, selective estrogen receptor modulator, teriparatide, calcium + vitamin D, calcium, and vitamin D. We defined the period for revision surgery as the final follow-up period.

RESULTS

Raloxifene, bisphosphonate, calcium + vitamin D, and denosumab for prosthetic hip function might have minimal differences when compared with placebos. The magnitude of the anti-osteoporotic drug effect on periprosthetic femoral bone loss varied across different Gruen zones. Bisphosphonate, denosumab, teriparatide might be more effective than placebo in Gruen zone 1 at 12 months after THA. Additionally, bisphosphonate might be more effective than placebo in Gruen zones 2, 5, 6, and 7 at 12 months after THA. Denosumab was efficacious in preventing bone loss in Gruen zones 6 and 7 at 12 months after THA. Teriparatide was likely to be efficacious in preventing bone loss in Gruen zone 7 at 12 months after THA. Raloxifene was slightly efficacious in preventing bone loss in Gruen zones 2 and 3 at 12 months after THA. Calcium was slightly efficacious in preventing bone loss in Gruen zone 5 at 12 months after THA. None of the studies reported revision surgery.

CONCLUSIONS

Bisphosphonate and denosumab may be effective anti-osteoporotic drugs for preventing periprosthetic proximal femoral bone loss due to stress shielding after THA, particularly in cementless proximal fixation stems, which are the most commonly used prostheses worldwide.

Osseointegration Pharmacology: A Systematic Mapping Using Artificial Intelligence

Clinical performance of osseointegrated implants could be compromised by the medications taken by patients. The effect of a specific medication on osseointegration can be easily investigated using traditional systematic reviews. However, assessment of all known medications requires the use of evidence mapping methods. These methods allow assessment of complex questions, but they are very resource intensive when done manually. The objective of this study was to develop a machine learning algorithm to automatically map the literature assessing the effect of medications on osseointegration. Datasets of articles classified manually were used to train a machine-learning algorithm based on Support Vector Machines. The algorithm was then validated and used to screen 599,604 articles identified with an extremely sensitive search strategy. The algorithm included 281 relevant articles that described the effect of 31 different drugs on osseointegration. This approach achieved an accuracy of 95%, and compared to manual screening, it reduced the workload by 93%. The systematic mapping revealed that the treatment outcomes of osseointegrated medical devices could be influenced by drugs affecting homeostasis, inflammation, cell proliferation and bone remodeling. The effect of all known medications on the performance of osseointegrated medical devices can be assessed using evidence mappings executed with highly accurate machine learning algorithms.

Bisphosphonates Can Maintain Periprosthetic Bone Mass Density after Total Hip Replacement, with Controversy in Region of Interest 5

BACKGROUND

Total hip replacement (THR) is the standard surgical treatment of hip diseases. Periprosthetic bone mass density (BMD) loss may be a cause for revision surgery. Bisphosphonates (BPs) are now the principal class medications for osteoporosis.

OBJECTIVE

To demonstrate the effect of BPs on treating periprosthetic osteoporosis after THR via a meta-analysis of randomized controlled trials (RCTs).

METHODS

A comprehensive search of PubMed, EMBASE, the Web of Science and the Cochrane Central Register of Controlled Trials was performed for RCTs on the effect of BPs on treating periprosthetic osteoporosis after THR and clinical outcomes relative to controls. The primary outcome measures were the change in BMD in each region of interest (ROI), the change in serum bone turnover marker levels, the change in functional parameters and the risk of adverse effects (AEs). The final search was performed in March, 2020.

RESULTS

Nine RCTs were included. A total of 359 patients met the inclusion criteria. BPs can clearly maintain periprosthetic BMD in ROIs at 1, 2, 3, 4, 6 and 7 at 6, 12 and 24 months. In addition, BPs can clearly decrease serum procollagen type 1 N-terminal propeptide (P1NP) levels at 12 months. There was no significant difference in the risk of AEs between the BP and control groups; however, BPs can cause more patients to decline participation.

CONCLUSION

BPs can effectively maintain overall periprosthetic BMD, but BMD in ROI 5 remains controversial. In addition, the safety of BPs is relatively high, but the compliance may be relatively low.

Prophylactic efficacy on periprosthetic bone loss in calcar region after total hip arthroplasty of antiosteoporotic drugs: a network meta-analysis of randomised controlled studies

OBJECTIVES

The aim of this study was to evaluate the effect of antiosteoporotic drugs on preventing periprosthetic bone loss in calcar 6 and 12 months after total hip arthroplasty.

METHODS

The network meta-analysis was conducted guided by the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline. A systematic literature search was conducted and 21 studies that enrolled a total of 955 patients with 9 antiosteoporotic drugs met the inclusion criteria. Network meta-analysis and conventional meta-analysis were carried out for calculating standard mean difference (SMD) and the surface under cumulative ranking curve (SUCRA) of the bone mineral density (BMD) in calcar (Gruen zone 7) as well as bone turnover markers (BTMs) including bone-specific alkaline phosphatase (BSAP) and collagen type I cross-linked N telopeptide (NTX) at 6 and 12 months between different antiosteoporotic drugs.

RESULTS

At 6 months after total hip arthroplasty, zoledronate (SUCRA=86.4%), risedronate (SUCRA=51.3%) and etidronate (SUCRA=44.5%) were effective in retaining BMD in calcar; zoledronate was significantly more effective than etidronate (SMD=0.65, 95% CI 0.03 to 1.27). Teriparatide (SUCRA=84.5%), denosumab (SUCRA=82.5%), zoledronate (SUCRA=69.2%), alendronate+alfacalcidol (SUCRA=66.2%) and etidronate (SUCRA=51.5%) were the top five drugs in retaining BMD in calcar at 12 months after total hip arthroplasty and the efficacy were comparable. After simultaneously excluding studies in which the prosthesis were cement and the drug dosages as well as treatment durations were inconsistent with those in treating osteoporosis, the above results were robust with the exception that alendronate showed significant efficacy compared with placebo (SMD=1.22, 95% CI 0.46 to 1.99) and was comparable with those effective drugs at 12 months. Long-term residual effect was corroborated only in etidronate, alendronate and zoledronate from previous studies. BTMs were significantly decreased as early as 6 months (SMD of BSAP -0.49, 95% CI -0.84 to -0.13; SMD of NTX -0.93, 95% CI -1.21 to -0.64) and sustained until 12 months (SMD of BSAP -0.27, 95% CI -0.50 to -0.03; SMD of NTX -0.84, 95% CI -1.11 to -0.56) during the prophylaxis.

CONCLUSIONS

Antiosteoporotic drugs showed prophylactic efficacy on periprosthetic bone loss after total hip arthroplasty in calcar, the effectiveness varied. Zoledronate was the best recommendation due to its optimal efficacy both within 6 and 12 months as well as its residual effect in the long term. BTMs could be used as indicators for monitoring through the treatment. More head-to-head clinical trials are needed to confirm those findings.

Effect of switching administration of alendronate after teriparatide for the prevention of BMD loss around the implant after total hip arthroplasty, 2-year follow-up: a randomized controlled trial

BACKGROUND

Stress shielding after total hip arthroplasty (THA) can induce bone mineral density (BMD) loss around the femoral implant. Several studies using drug have described methods to prevent BMD loss around implants following THA. Switching from teriparatide to alendronate was reported to increase lumbar BMD; on the other hands, it is unclear whether switching from teriparatide to alendronate is effective around the implant. The aim of this study is that changes in BMD is compared in patients switched from teriparatide to alendronate, in patients treated with alendronate alone, and in control patients without medication after total hip arthroplasty.

PATIENTS AND METHODS

Patients were randomized into three groups, those switched to alendronate after teriparatide (switch: n = 17), those receiving continuous alendronate (ALD: n = 15), and control untreated patients (control: n = 16) and followed up for 2 years after THA. Baseline periprosthetic BMD was measured by dual-energy X-ray absorptiometry (DEXA) 1 week after THA, followed by subsequent measurements at 1 and 2 years postoperatively. Lumbar BMD was also evaluated at preoperatively, 1 and 2 years postoperatively.

RESULTS

Two years after surgery, BMD (%) at zone 1 was significantly higher in the switch group than in the control group (P = 0.02). BMD (%) at zone 7 was significantly higher in the switch and ALD groups than in the control group (P = 0.01, P = 0.03). Lumbar BMD (%) anterior-posterior (AP) side was significantly higher in the switch group than in the ALD and control groups 2 years after surgery. On the other hand, lumbar BMD (%) lateral side was significantly higher in the switch and ALD groups than control group 2 years after surgery.

CONCLUSIONS

Switching therapy had a significant effect on BMD of the lumbar spine and zones 1 and 7 at 2 years postoperatively. At zone 1 in particular, it was found to be more effective than ALD alone.

TRIAL REGISTRATION

UMIN, registry number UMIN000016158. Registered 8 January 2015.

Effects of bisphosphonates in preventing periprosthetic bone loss following total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

Periprosthetic bone loss following total hip arthroplasty (THA) was a well-known phenomenon. This systematic review was to assess the effectiveness of bisphosphonates (BPs) for decreasing periprosthetic bone resorption.

METHODS

The MEDLINE, EMBASE, and Cochrane Library databases were searched up to March 2018. Randomized controlled trials compared the effects between administrating BPs and placebo or no medication were eligible; the target participants were patients who underwent THA. Mean differences (MD) and 95% confidence interval (95% CI) were calculated by using the random-effects models. Statistical analyses were performed by RevMan 5.3 software.

RESULTS

Fourteen trials involving 620 patients underwent THA were retrieved. BPs significantly prevented the loss of periprosthetic bone mineral density at 1 year (MD, 0.06 [95% CI, 0.03 to 0.08], p < 0.001), between 2 and 4 years (MD, 0.04 [95% CI, 0.01 to 0.07], p = 0.02), and more than 5 years after THA (MD, 0.08 [95% CI, 0.06 to 0.11], p < 0.001). Both serum bone alkaline phosphatase (MD, - 7.28 [95% CI, - 9.81 to - 4.75], p < 0.001) and urinary N-telopeptide of type I collagen (MD, - 24.37 [95% CI, - 36.37 to - 12.37], p < 0.001) in BP group were significantly lower. Subgroup analyses showed that the third-generation BPs were more effective in decreasing periprosthetic bone loss than the first and second generation within 1 year after THA (p = 0.001).

CONCLUSION

BPs were beneficial to decreasing periprosthetic bone loss. The third-generation BPs showed significantly efficacy for patients in short-term observation.

Bisphosphonates for the preservation of periprosthetic bone mineral density after total joint arthroplasty: a meta-analysis of 25 randomized controlled trials

The present meta-analysis aimed to evaluate the long-term efficacy of bisphosphonates (BPs) on preservation of periprosthetic bone mineral density (BMD) after joint arthroplasty. It confirmed the protective effect of BPs in a long-term follow-up, and found the influence factors on this effect.

INTRODUCTION

Periprosthetic bone loss is believed to cause aseptic loosening and failed prosthetic fixation in joint arthroplasty. This meta-analysis which included high-quality randomized controlled trials aimed to analyze the effect of bisphosphonates on maintaining periprosthetic bone mineral density after total joint arthroplasty.

METHODS

Twenty-five RCTs were included and the total number of participants was 1163 by computerized searches of bibliographic databases. The weighted mean differences with 95% confidence interval were calculated to evaluate the efficacy of BPs on total periprosthetic BMD and the BMD of different Gruen zones. Subgroup analyses identified the potentially influencing factors such as surgical site, cement fixation, and generation of BPs. A descriptive review was conducted for BP-related adverse effects.

RESULTS

The BPs group presented significantly higher total periprosthetic BMD in the BPs group than that in the control group at 3, 6, 12 months, 2-4 years, and 5-10 years after arthroplasty (P < 0.05). The BPs group presented significantly higher periprosthetic BMD in femoral Gruen Zone 1 and 7 than that in the control group at 3, 6, 12 months, 2-4 years, and 5-10 years (P < 0.05). The heterogeneity was minimized by dividing THA and TKA into two subgroups. Subgroup analyses revealed that the effect of BPs on preservation of BMD was significantly greater in arthroplasty with cemented component than in that with uncemented component at 12 months and 5-10 years (P < 0.05), and the administration of the second and third generation BPs was significantly more effective than the first-generation BPs at 6 and 12 months (P < 0.05). None of the included studies described severe or fatal adverse effects related to BPs.

CONCLUSIONS

BPs have significantly long-term efficacy on the preservation of periprosthetic BMD after joint arthroplasty. To obtain a better efficacy, the cemented components and the second and third generation BPs are recommended.

Association of Bisphosphonate Use and Risk of Revision After THA: Outcomes From a US Total Joint Replacement Registry

BACKGROUND

Total hip arthroplasty (THA) is often performed in patients who are older and may take bisphosphonates to treat a variety of conditions, most commonly osteoporosis. However, the clinical effects of bisphosphonate use on patients who have undergone THA are not well described.

QUESTIONS/PURPOSES

(1) Is bisphosphonate use in patients with osteoarthritis undergoing primary THA associated with a change in the risk of all-cause revision, aseptic revision, or periprosthetic fracture compared with patients not treated with bisphosphonates? (2) Does the risk of bisphosphonate use and revision and periprosthetic fracture vary by patient bone mineral density and age?

METHODS

A retrospective cohort study of 12,878 THA recipients for the diagnosis of osteoarthritis was conducted; 17.8% of patients were bisphosphonate users. Data sources for this study included a joint replacement registry (93% voluntary participation) and electronic health records and an osteoporosis screening database with complete capture of cases as part of the Kaiser Permanente integrated healthcare system. The endpoints for this study were revision surgery for any cause, aseptic revision, and periprosthetic fracture. The exposure of interest was bisphosphonate use; patients were considered users if prescriptions were continuously refilled for a period equal to or longer than 6 months. Bone quality (based on dual-energy x-ray absorptiometery ordered based on the National Osteoporosis Foundation's clinical guidelines taken within 5 years of the THA) and patient age (< 65 versus ≥ 65 years) were evaluated as effect modifiers. Patient, surgeon, and hospital factors were evaluated as confounders. Cox proportional hazards models were used. Hazard ratios (HRs) and 95% confidence intervals (CIs) were determined.

RESULTS

Age- and sex-adjusted risks of all-cause (HR, 0.50; 95% CI, 0.33-0.74; p < 0.001) and aseptic revision (HR, 0.53; 95% CI, 0.34-0.81; p = 0.004) was lower in bisphosphonate users than in nonusers. The adjusted risk of periprosthetic fractures in patients on bisphosphonates was higher than in patients not on bisphosphonates (HR, 1.92; 95% CI, 1.13-3.27; p = 0.016). Lower risks of all-cause revision and aseptic revision were observed in patients with osteopenia (HR, 0.49; 95% CI, 0.29-0.84; and HR, 0.53; 95% CI, 0.29-0.99, respectively) and osteoporosis (HR, 0.22; 95% CI, 0.08-0.62; and HR, 0.33; 95% CI, 0.11-0.99, respectively).

CONCLUSIONS

Patients considered bisphosphonate users who underwent THA had a lower risk for revision surgery. Bisphosphonate use was associated with a higher risk of periprosthetic fractures in younger patients with normal bone quantity. Evaluation of bone quality and bisphosphonate use for the diagnosis of osteoporosis is encouraged in patients with osteoarthritis who are candidates for primary THA. Further research is required to determine the optimal duration of therapy because long-term bisphosphonate use has been associated with atypical femur fractures.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Effect of bisphosphonates in preventing femoral periprosthetic bone resorption after primary cementless total hip arthroplasty: a meta-analysis

Background

Bone loss leading to aseptic loosening of the prosthesis and periprosthetic fracture is a mode of failure in cementless total hip arthroplasty (THA). The aim of this meta-analysis was to evaluate the effect of bisphosphonates in preventing femoral periprosthetic bone resorption following primary cementless THA zone by zone.

Method

Clinical randomized controlled trials concerning bisphosphonates application after primary cementless THA published up to October 2014 were retrieved from PubMed, Cochrane library, and Embase databases. The methodological quality of the included studies was assessed by the Physiotherapy Evidence Database (PEDro) scale. Data analysis was performed using StataSE12.0.

Results

Ten randomized controlled trials involving a total of 502 patients were assessed; the bisphosphonates group included 256 patients and the control group included 246 patients. The meta-analysis showed that the bone mineral density (BMD) of most femoral periprosthetic zones in bisphosphonates group was significantly higher than that in the control group at 3 months postoperatively except zone 5 with no significant difference. At 6 and 12 months, the BMD of bisphosphonates group was much higher than that in control group except zone 5, which showed no statistical difference. The BMD of bisphosphonates group was persistently higher than control group in zone 6 and 7 at 5 years postoperatively, while the other zones had no significant difference. Both serum bone alkaline phosphatase and urinary type I collagen N-telopeptide were significantly suppressed by bisphosphonates at 3, 6, and 12 months.

Conclusion

Bisphosphonates seem to decrease early femoral periprosthetic bone resorption after primary cementless THA. Drug efficacy was found to be long-standing in the main load-bearing zones.

Systematic analysis of bisphosphonate intervention on periprosthetic BMD as a function of stem design

The purpose of this study was to determine the effects of bisphosphonates periprosthetic BMD in THA patients as a function of stem design. Specifically, the goals were to determine if bisphosphonates as a group could significantly inhibit periprosthetic bone loss, time needed to see an effect, if one drug was more effective than the others, and if there was a difference due to stem design or cement. Thirteen articles met the inclusion criteria. Overall, groups treated with bisphosphonate therapy preserved significantly more BMD than the control groups as early as six months postoperatively, and orally delivered bisphosphonates were most effective. Furthermore, the biggest differences were in patients with non-cemented stems, and of those, the largest differences were seen in patients with fully coated CoCr stems.

A meta-analysis of bisphosphonates for periprosthetic bone loss after total joint arthroplasty

BACKGROUND

Periprosthetic bone loss, which is common after joint arthroplasty, may cause bone loosening and lead to failed prosthetic fixation. Two previous meta-analyses have confirmed the mid-term effect of bisphosphonates (BPs) in preventing bone loss after arthroplasty. To determine long-term efficacy and gender bias of BPs after joint arthroplasty, we conducted a meta-analysis based on 17 RCTs involving 781 patients to evaluate the effect of BPs.

METHODS

Meta-analysis was conducted after a systematic search of Medline, Embase, the Cochrane Collaboration Central Register of Controlled Clinical Trials, CINAHL, and ISI Web of Science, and manual examination of references in selected articles and conference abstracts of key orthopedic journals. Methodological quality and abstracted relevant data were evaluated. In addition to analysis of bone mineral density (BMD), we also conducted systematic analysis of clinically relevant outcomes and bone biochemical markers.

RESULTS

Seventeen trials involving a total of 781 patients were assessed. Significantly less periprosthetic bone loss occurred in the BP-treated group than in the control group at 6 and 12 months (p < 0.0001). This protective effect was not noted at 3 months (p = 0.11) nor from 24-72 months (p = 0.14). The efficacy of BPs in the gender balance, shorter duration, and the non-nitrogenous BPs groups was no different from that for controls. Biochemical bone markers were suppressed in the BPs group. However, clinically relevant outcomes in the BPs group and controls were similar at all times.

CONCLUSIONS

The overall moderate-quality evidence from the RCTs confirmed the significant mid-term efficacy of BPs on periprosthetic bone loss after joint arthroplasty. Long-term efficacy of BPs was not observed, and the therapy was of more benefit to women, especially postmenopausal women. To achieve better efficacy, nitrogenous BPs and long duration of treatment may be recommended.

Measurement of bone density around the Oxford medial compartment knee replacement using iDXA. A precision study

The goal of this study was to evaluate whether the Lunar iDXA densitometer can accurately measure the bone mineral density (BMD) around the tibial component of the Oxford unicompartment knee replacement (UKR). Both knees in 20 patients were measured 3 times in the supine position with repositioning between each scan. We chose 7 regions of interest to evaluate the bone density around the implant. Small but significant differences between the implant and nonimplanted knee were noticed with the nonimplanted knee having slightly higher BMD and bone mineral content (BMC) in areas 1-3 (p≤0.001) and area 6 (p=0.002). There was higher BMD in area 4 (p=0.028). The precision for BMD in the 7 areas of interest in the implanted knee varied between 0.55% and 4.04% and BMC between 1.8% and 5.3%. There was no significant difference in the precision between the nonimplanted and implanted knees. Prospective serial measurements around the Oxford UKR using iDXA will be able to assess specific areas of stress shielding and potential implant stability, which is likely to help predict the survival of the implant.

Bisphosphonates for periprosthetic bone loss after joint arthroplasty: a meta-analysis of 14 randomized controlled trials

The present meta-analysis aimed to evaluate the middle-term efficacy of bisphosphonates on maintaining periprosthetic bone mass after joint arthroplasty and the potential influential factors. It was found that the protective effect of bisphosphonates, probably modified by its generation and the prosthesis location, could persist in a middle-term follow-up after surgery and after drug discontinuation.

INTRODUCTION

A previous meta-analysis of 6 RCTs with follow-up of 12 months suggested that bisphosphonates (BPs) could prevent bone loss after arthroplasty up to 6 months. Our meta-analysis based on 14 RCTs involving 671 patients with follow-up up to 72 months aimed to evaluate the middle-term efficacy of BPs, understand the sources of heterogeneity, and comprehensively identify the potential influential factors.

METHODS

Electronic databases searching and hand searching of conference proceedings were conducted. We evaluated the methodological quality and abstracted relevant data. With fixed effect model we calculated the weighted mean differences to evaluate bone mineral density at different time points. We also conducted a systematic review for BP-related adverse effects.

RESULTS

The significantly less periprosthetic bone loss occurred in the BP-treated group than in the control group at 3, 6, and 12 months, and between 24 and 72 months after the index surgery. The protective effect persisted during 18 to 70 months after discontinuation of BPs. The heterogeneity was minimized with the separation of hip and knee trials during the analysis. The efficacy was more potent for the second and the third generation of BPs than the first generation. None of the trials noted serious or fatal adverse effects related to BPs.

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. To obtain a better efficacy, the second and the third generation of BPs may be the choice.

Etidronate: what is its place in treatment of primary osteoporosis and other demineralizing diseases today?

Bisphosphonate drugs are the major treatment options for primary and secondary osteoporosis and other demineralizing bone diseases. This class of drugs was presaged over a decade ago when etidronate disodium, the "mother compound" for modern-day bisphosphonates, was first used in the treatment of osteoporosis. The cyclic use of etidronate in therapy, which is known mainly to specialists in the field, is not approved in the United States. The drug does, however, have a worldwide reputation as a relatively inexpensive, efficacious, and highly tolerable treatment for osteoporosis. Many studies still describe its use for primary osteoporosis and some have described use in immobilization bone loss, periprosthetic bone loss, and even glucocorticoid-induced osteoporosis. This review highlights some of these uses.

Effect of etidronate on COX-2 expression and PGE(2) production in macrophage-like RAW 264.7 cells stimulated by titanium particles

BACKGROUND

The most common failure of total joint replacement is aseptic loosening in association with osteolysis. Previous reports have shown that prostaglandin E(2) (PGE(2)) secreted from macrophages that phagocytosed wear debris induced periprosthetic osteolysis. Many clinical studies have reported that bisphosphonate therapy reduced periprosthetic bone loss and loosening of the implants after total joint replacements. Bisphosphonates are synthetic compounds with the ability to decrease bone resorption. In addition, some bisphosphonates have been reported to have anti-inflammatory effects by reducing the secretion of pro-inflammatory cytokines. However, the mechanism of bisphosphonates that reduces periprosthetic bone resorption remains unclear. The purpose of this study was to investigate one of the mechanisms by which etidronate (EHDP) inhibits periprosthetic bone resorption.

METHODS

Macrophage-like RAW 264.7 cells were treated with EHDP at concentrations of 0.001, 0.01, 0.1, 1, 10, and 100 microM together with the titanium particles at a concentration of 1 mg/ml. After a 24-h culture period, total mRNA was isolated and reverse transcription-polymerase chain reaction (RT-PCR) was done to examine the expression of cyclooxygenase-2 (COX-2). The supernatants were also collected and production of PGE(2), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) were quantified using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Analyses showed that COX-2 expression and PGE(2) production were suppressed by EHDP in a dose-dependent manner. By 100 microM of EHDP, PGE(2) production of the cells was suppressed approximately to the level of the nonstimulated cells. Production of IL-1beta, IL-6, and TNF-alpha in the supernatant was also suppressed by EHDP.

CONCLUSIONS

The blockage effect of pro-inflammatory cytokines is a possible etidronate mechanism that reduces bone resorption around implants.