Bisphosphonates

Fixation Principles for Pathologic Fractures in Metasatic Disease

The management of pathologic fractures differs from nonpathologic fractures with respect to preoperative evaluation, surgical strategies, adjuvant therapies, and complication rates. These issues must be understood to provide appropriate musculoskeletal care for patients with metastatic disease.

[Analysis of pathological characteristics of medication-related osteonecrosis of the jaw and discussion of clinical treatment strategies based on the pathological analysis results]

OBJECTIVE

To summarize the pathological characteristics of medication-related osteonecrosis of the jaw (MRONJ) specimens after jaw curettage or jaw osteotomy treatment and to comprehensively analyze the relationship between the different pathological features, treatment methods, and treatment effects to provide new ideas for effective treatment of MRONJ in clinical work.

METHODS

The clinical and pathological data were collected from 23 patients with MRONJ who were treated with curettage (18 patients) and jaw osteotomy (5 patients) at the Department of Oral and Maxillofacial Surgery of Peking University Hospital of Stomatology between June 2014 and December 2015. The pathological characteristics of MRONJ were summarized and analyzed with treatment effects based on various surgical treatment methods. The diagnostic criteria and disease staging of MRONJ were determined according to the 2014 American Association of Oral and Maxillofacial Surgeon's Position Paper.

RESULTS

In this study, 5 patients have treated with jaw segmental osteotomy, and all of them were in stage Ⅲ; the other 18 patients were treated with jaw curettage, including 5 patients in stage Ⅱ and 13 patients in stage Ⅲ. The pathological features of MRONJ in five cases of jaw segmental osteotomy were divided into three adjacent regions from shallow to deep: inflammation region (IR), sclerosis region (SR), and bone remodeling layer (BRL). Moreover, three types of pathological features of specimens from traditional curettage were defined as type 1 (IR), type 2 (IR + SR), and type 3 (IR + SR + BRL). The pathological features of the patients treated with jaw curettage were: type Ⅰ, 38.9% (7/18); type Ⅱ, 44.4% (8/18); type Ⅲ, 16.7% (3/18). Complete healing was achieved in 5 patients treated with jaw segmental osteo-tomy. Moreover, 2 cases with type Ⅰ, 1 case with type Ⅱ, and 1 with type Ⅲ completely healed after jaw curettage, while 5 cases with type Ⅰ, 7 cases with type Ⅱ, and 2 cases with type Ⅲ experienced recurrence after surgery.

CONCLUSION

Pathological features of continuous regions of inflammation, sclerosis, and bone remodeling layer were identified from shallow to deep, based on the microscopic observation of jaw segmental osteotomy samples. Insufficient removal of the sclerotic region during jaw curettage that blocks the required blood, nutritional factors, and mesenchymal stem cells seems to be a common cause for failed treatment of MRONJ after curettage surgery.

The Efficacy and Safety of Chinese Herbal Medicine Xianling Gubao Capsule Combined With Alendronate in the Treatment of Primary Osteoporosis: A Systematic Review and Meta-Analysis of 20 Randomized Controlled Trials

Objective: Herein, we purposed to evaluate the efficacy along with the safety of Xianling Gubao capsule (XLGB) combined with alendronate (ALE) for primary osteoporosis (POP) from the current literature.

Materials and Methods: We carried out a search for electronic literature in the PubMed, Chinese National Knowledge Infrastructure, EMBASE, Wanfang Web of Science, Chinese Biomedical Literature Database, Cochrane Library, as well as Chinese VIP databases targeting articles published from inception to December 2020. Only randomized controlled trials (RCTs) were enrolled into the study. Alkaline phosphatase (ALP), visual analogue scale (VAS), serum phosphorus (S-P), bone gla protein (BGP), serum calcium (S-Ca) and bone mineral density (BMD) were the primary outcome variable. The total clinical effective rate along with the adverse drug reaction (ADR) were the secondary outcome variables. The meta-analysis was conducted using RevMan 5.3 and STATA 12.0. GRADE pro3.6.1 software was used for the assessment of evidence quality.

Results: Overall, 20 RCTs focusing on 1911 patients were enrolled into the study. Our meta-analysis demonstrated that XLGB combined with ALE remarkably increased BMD (p < 0.001), BGP (p < 0.001), S-Ca (p < 0.001), S-P (p < 0.001) and effective rate (p < 0.001) than ALE alone in patients with POP. Moreover, ALP (p < 0.001) and VAS (p < 0.001) were overtly by decreased XLGB. However, XLGB combined with ALE would not markedly increase the rate of ADR in contrast with ALE alone (p = 0.499).

Conclusion: The results of our study demonstrated that XLGB is a potential candidate for OP treatment. We recommend that rigorous, as well as high-quality trials involving large samples sizes should be conducted to confirm our findings.

Bone union after spinal fusion surgery using local bone in long-term bisphosphonate users: a prospective comparative study

Bisphosphonates are the most commonly used drugs for osteoporosis and long-term use of bisphosphonates may affect fusion rate after spinal fusion surgery. There was significant delayed union after 6 months in long-term bisphosphonates users; however, there were no significant difference in fusion rate of long-term bisphosphonate users. Therefore, spinal fusion surgery should not be hesitated in long-term bisphosphonates users.

PURPOSE

Bisphosphonates (BPs) are the most popular class of drugs for treatment of postmenopausal osteoporosis. Long-term use of BPs may also inhibit the spinal fusion process after posterior lumbar interbody fusion (PLIF). We compared bone fusion rates of long-term BPs users and non-users after undergoing spinal fusion surgery.

METHODS

A total of 97 postmenopausal women who were candidates for single-level PLIF were recruited from 2015 to 2016. Participants were divided into two groups, with 63 patients in a long-term BPs user group and 34 patients in a non-user group. Serum C-terminal cross-linking telopeptide (CTX) levels were checked for bone resorption markers. Bone fusion rates were calculated at 6 months and 1 and 2 years after the surgery. Clinical outcomes were measured using the Oswestry Disability Index (ODI) and visual analog scale (VAS).

RESULTS

Serum CTX level was dramatically decreased in the long-term BPs user group (p < 0.05). Fusion rates at 6 months after surgery were 42% in the non-user group and 26% in the long-term BPs user group (p = 0.035). However, fusion rates were 82% in the long-term BPs user group and 87% in the non-user group at 2 years after surgery (p > 0.05). There was no significant difference between the two groups in ODI or VAS.

CONCLUSIONS

Even though there was significant delayed union after 6 months in long-term BPs users, at the 2-year postoperative follow-up, there was no significant difference in bone fusion rate between the two groups. Long-term BPs users showed fusion rates greater than 80% and clinical outcome improvements that were comparable to those in non-users. No significant effect on fusion rate after PLIF was found in long-term BPs users.

Effects of alendronate for treatment of glucocorticoid-induced osteoporosis: A meta-analysis of randomized controlled trials

BACKGROUND

Alendronate has been used to prevent or treat glucocorticoid-induced osteoporosis (GIO), data regarding its efficacy are inconsistent. We conducted the current systematic review and meta-analysis to evaluate both efficacy and safety of alendronate in the treatment of GIO.

METHODS

PubMed, Embase, the Cochrane Controlled Trials Registry, and the China Academic Journal Network Publishing Databases were searched up through March 1, 2018. Randomized controlled trials (RCTs) involving patients which received alendronate treatment were included. Outcome measures were bone mineral density (BMD) changes, bone fractures, and adverse reactions. Data from the individual studies were pooled using random or fixed effect models based on heterogeneity. Effect size was reported as standardized mean differences (SMD) for continuous outcomes and pooled odds ratios (OR) for dichotomous outcomes, with 95% confidence interval (CI).

RESULTS

Overall, 10 studies involving 1002 patients were included in the present investigation. Alendronate treatment significantly increased BMD of the lumbar spine and femoral neck during 6 to 24 months. These beneficial effects were apparent at 12 months after treatment for the lumbar spine but not the femoral neck BMD. Alendronate treatment did not significantly change fracture risk nor induce significant differences in adverse gastrointestinal effects.

CONCLUSION

Alendronate significantly increases BMD of the lumbar spine and femoral neck in patients with GIO, but does not appear to reduce the risk of fractures. As relatively insufficient data regarding the GIO fracture incidence has been reported, more RCTs need to be carried out to determine the efficacy of alendronate in the prevention of GIO fracture.

PROTECTIVE EFFECT OF VANILLIC ACID ON OVARIECTOMY-INDUCED OSTEOPOROSIS IN RATS

Background:

The need for an anti-osteoporotic agent is in high demand since osteoporosis contributes to high rates of disability or impairment (high osteoporotic fracture), morbidity and mortality. Hence, the present study is designed to evaluate the protective effects of vanillic acid (VA) against bilateral ovariectomy-induced osteoporosis in female Sprague-Dawley (SD) rats.

Materials and Methods:

Forty healthy female adult SD rats were separated in to four groups with sham-operated control with bilateral laprotomy (Sham; n = 10), bilateral overiectomy (OVX; n = 10) group, OVX rats were orallay administrated with 50 mg/kg b.wt of VA (OVX + 50 VA; n = 10) or 100 mg/kg b.wt of VA (OVX + 100 VA; n = 10) for 12 weeks (post-treatment) after 4 weeks of OVX.

Results:

A significant change in the body weight gain was noted in OVX group, while treatment with VA substantially reverted to normalcy. Meanwhile, the bone mineral density and content (BMD and BMC) were substantially improved on supplementation with VA. Also, the bone turnover markers like calcium (Ca), phosphorous (P), osteocalcin (OC), alkaline phosphatase (ALP) and deoxypyridinoline (DPD) and inflammatory markers (IL-1β, IL-6, and TNF-α) levels were markedly attenuated in VA-treated rats. Moreover, the biomechanical stability was greatly ameliorated with VA administration. Both the dose of VA showed potent anti-osteoporotic activity, but VA 100 mg showed highest protective effects as compared with 50 mg of VA.

Conclusion:

Based on the outcome, we concluded that VA 100 showed better anti-osteoporotic activity by improving BMD and BMC as well as biomechanical stability and therefore used as an alternative therapy for treating postmenopausal osteoporosis.

Femoral Fractures Following Long-term Bisphosphonate Use

Bisphosphonates are widely used for the prevention of osteoporosis-associated fractures. Femoral fractures associated with bisphosphonate use are increasingly being reported in the literature. Orthopedic surgeons should be aware of this potential association and related implications for patient treatment. Bisphosphonate-associated fractures are characteristically simple, transverse with beaking, and subtrochanteric. Diagnosis is based on a careful history, physical examination, and focused imaging. In the setting of either a complete or partial fracture, it is recommended that bisphosphonate therapy be halted and calcium and vitamin D brought into the therapeutic range. Orthopedic management of the completed fracture preferably uses a locked intramedullary nail. The recommendations for incomplete fractures are unresolved. [Orthopedics. 2016; 39(6):e1036-e1040.].

Management of osteoporosis in spine surgery

Osteoporosis is a burgeoning clinical problem that is characterized by decreased bone strength and density. It predisposes patients to fragility fractures and debilitating spine deformities. Several complications are associated with spine surgery in patients with osteoporosis, and there is currently no treatment algorithm to guide the spine surgeon. A multidisciplinary approach to treatment of patients with osteoporosis and spine deformity or fracture is encouraged, and preoperative planning is crucial for successful surgical outcomes. Several surgical techniques have been developed to treat osteoporosis-related deformities, including posterior instrumentation with fusion. However, achieving fixation and fusion in these patients can be difficult secondary to poor bone stock. Augmentation methods to improve pedicle screw fixation have evolved, including instrumentation at multiple levels, bioactive cement augmentation, and fenestrated or expandable pedicle screws, but their impact on clinical outcomes remains unknown. Management of osteoporosis in patients undergoing spine surgery is challenging, but with appropriate patient selection, medical optimization, and surgical techniques, these patients can experience pain relief, deformity correction, and improved function.

The effect of zoledronic acid on the volume of the fusion-mass in lumbar spinal fusion

Background

Few studies have explored the effects of bisphosphonates on bony healing in patients undergoing spinal fusion surgery. Most previous studies used animal models and found that bisphosphonate shows negative effects on spinal fusion consolidation. We intended to evaluate the effect of a single-dose of zoledronic acid on the volume of the fusion-mass in lumbar spinal fusion.

Methods

A retrospective review was carried out on 44 patients with symptomatic degenerative lumbar spinal stenosis who underwent one or two-level posterolateral fusion from January 2008 and January 2011. They were divided into 4 groups: group 1, autograft and zoledronic acid; group 2, allograft and zoledronic acid; group 3, autograft alone; and group 4, allograft alone. Functional radiography and three-dimensional computed tomography scans were used to evaluate and quantify the volume of the fusion-mass. The visual analog scale (VAS), the Oswestry disability index (ODI), and the short form 36 (SF-36) were used to evaluate the clinical outcomes.

Results

The mean volume of the fusion-mass per level was 8,814 mm³, 8,035 mm³, 8,383 mm³, and 7,550 mm³ in groups 1, 2, 3, and 4, respectively, but there were no significant differences between the groups (p = 0.829). There were no significant decreases in the volume of the fusion-mass (p = 0.533) in the zoledronic acid groups (groups 1 and 2). The VAS, the ODI, and the SF-36 at the 6-month follow-up after surgery were not significantly different (p > 0.05) among the 4 groups. The VAS, the ODI, and the SF-36 were not correlated with the volume of the fusion-mass (p = 0.120, 0.609, 0.642).

Conclusions

A single dose of zoledronic acid does not decrease the volume of the fusion-mass in patients undergoing spinal fusion with osteoporosis. Therefore, we recommend that zoledronic acid may be used after spinal fusion in osteoporotic patients.

Basic science of bone healing

Bone healing is a complex process that can be influenced by both host and environmental factors. In this article, we review the biology involved in the regeneration of new bone after fracture, and factors influencing bone healing, including diabetes, smoking, NSAID use, and bisphosphonates.

Alendronate retards the progression of lumbar intervertebral disc degeneration in ovariectomized rats

OBJECTIVE

Increasing evidence has revealed a positive correlation between postmenopausal osteoporosis and intervertebral disc degeneration, the underlying mechanism of which might be associated with changes in the vertebral bone and endplate. Alendronate (ALN) can increase bone mass and improve the microstructure of osteoporotic vertebrae, which might be helpful in preserving disc morphology and mechanical properties. This study aims to investigate the effects of ALN on lumbar intervertebral disc degeneration related to osteoporosis using an ovariectomized (OVX) rat model.

METHODS

Thirty female Sprague-Dawley rats aged 3 months were randomly divided into three groups (with 10 rats each) as follows: the Sham group underwent sham surgery; the OVX + ALN group had twice-a-week subcutaneous injections of ALN (15 μg/kg) for 6 months. The OVX + V group received an equivalent volume of saline solution as placebo post-OVX. After animals were sacrificed at 6 months post-OVX, the L3-6 spinal segments were harvested. Bone mineral density (BMD), micro-CT analysis and biomechanical testing were performed to evaluate the bone quality and microstructural changes in the lumbar vertebral bodies. Histological analysis with van Gieson stain and the histological score were used to identify the characteristics of the degenerative discs. The disc height and the thickness of the cartilage endplate were measured and compared. Immunohistochemistry and real-time PCR measurements for aggrecan, type I collagen, type II collagen, and matrix metalloprotease (MMP)-1, MMP-3 and MMP-13 expressions on the disc were performed to assess the underlying molecular signaling changes in matrix metabolism during intervertebral disc degeneration.

RESULTS

The OVX + ALN group significantly maintained vertebrae BMD, percent bone volume and biomechanical strength, when compared with the OVX + V group. Histological evaluation suggests that there was no significant difference in disc height between the OVX + ALN and Sham groups, and ALN significantly prevented cartilage endplate thickening and the development of abnormal bony tissues within the cartilage endplate. The histological score in the OVX + ALN group was significantly lower than the OVX + V group, suggesting that ALN treatment was effective in delaying the process of the disc degeneration. The results of molecular analysis revealed a significant increase in aggrecan and type II collagen expressions, but marked reductions in MMP-1, MMP-3 and MMP-13 expressions at both the protein and mRNA levels in the OVX + ALN group.

CONCLUSIONS

ALN can retard the progression of lumbar intervertebral disc degeneration in OVX rats. The underlying mechanisms might be related to preservation of the structural integrity and function of the adjacent structures, including the vertebrae and endplates, which further links with modulations in extracellular matrix metabolism to protect the disc from degeneration. These results suggest that ALN might be a promising drug agent for preventing lumbar intervertebral disc degeneration related to osteoporosis.

Predictors of oral bisphosphonate prescriptions in post-menopausal women with osteoporosis in a real-world setting in the USA

SUMMARY

We identified factors associated with oral bisphosphonate treatment in 50+-year-old female patients with a first fracture, osteoporosis diagnosis, or BMD < or =-2.5 in the Geisinger Health System electronic health record database. Treatment was positively associated with age, oral corticosteroids, and smoking, and negatively associated with body mass index and bone mineral density scores.

INTRODUCTION

To identify factors associated with oral bisphosphonate treatment in patients with an indicator for post-menopausal osteoporosis.

METHODS

Females age 50+ years with a first fracture, osteoporosis diagnosis, or bone mineral density (BMD) < or =-2.5 (index date) were identified in the Geisinger Health System electronic health record database. Treatment was defined as an oral bisphosphonate prescription order (risedronate sodium, ibandronate sodium, or alendronate) < or =90 days post-index date. Treatment rates were assessed and a multivariate logistic model was used to identify predictors of treatment separately for patients with fracture (FRAC) and with diagnosis or low BMD (ICD-9-BMD).

RESULTS

The FRAC group had 2,003 female patients with a mean (SD) age of 69.0 (+/-11.3) years and the ICD-9-BMD group had 12,976 female patients with a mean (SD) age of 66.9 (+/-10.0) years. Within 90 days of the index date of fracture, diagnosis, or low BMD score, 188 (9.4%) patients in the FRAC group and 5,395 (41.6%) in the ICD-9-BMD group received treatment. Treatment was positively associated with age and oral corticosteroids and negatively associated with body mass index and subsequent BMD in both groups. Smoking currently was positively associated with treatment in the ICD-9-BMD group.

CONCLUSION

Certain patient characteristics are predictors of physicians prescribing oral bisphosphonates. However, many patients remain untreated.

Effect of a single dose of pamidronate administered at the time of surgery in a rabbit posterolateral spinal fusion model

Spinal fusion is usually performed on patients who receive bisphosphonates (BP); however, limited data on their action on spinal fusion are available. Previous studies in animal models have shown that chronic administrations of BP reduced spinal fusion rates, and only one study has shown that a single dose administration of zolendronic acid increased fusion rate. The objective of the present study was to evaluate if pamidronate (PA), which was previously demonstrated to reduce spinal fusion rate when administered continuously for 8 weeks, would increase the spinal fusion rate if administered in a single dose at the time of surgery in a rabbit model. Thirty-two New Zealand rabbits underwent an L5-L6 posterolateral intertransverse fusion with iliac crest autograft. Animals were randomized to receive either PA 3 mg/kg in a single dose immediately after surgery, or normal saline. Animals were killed 8 weeks after surgery and fusion was determined by manual palpation and radiographic analysis. Fusion healing was obtained in eight rabbits (50%) in the PA group and in four animals (25%) in the control group, p = 0.137. In a rabbit model, a single dose of PA did not decrease lumbar spinal arthrodesis consolidation rates, but it obtained a nonsignificant higher spinal fusion rate.

Alendronate inhibits PTH (1-34)-induced bone morphogenetic protein expression in MC3T3-E1 preosteoblastic cells

The bisphosphonate class of antiresorptive drugs and active forms of parathyroid hormone (PTH (1-34)) have been used clinically to enhance bone mass and density in patients with osteoporosis. Abundant evidence suggests that the mechanism by which PTH (1-34) increases bone density is stimulation of osteoblast differentiation. Although bisphosphonates have been classically thought to increase bone density by inhibiting osteoclasts, there is increasing evidence to suggest that bisphosphonates have direct stimulatory effects on osteoblast differentiation. Interestingly, in patients with osteoporosis, combination therapy with bisphosphonates and PTH (1-34) is not synergistic in increasing bone density; bisphosphonates appear to blunt the effect of PTH (1-34). To begin to understand the mechanism governing the effects of these agents on osteoblasts and a possible explanation for their apparent antagonism, we examined the expression of several bone morphogenetic proteins (BMPs) in MC3T3-E1 preosteoblastic cells either untreated, or treated with alendronate, parathyroid hormone, or a combination of the two agents. We find by reverse transcriptase-polymerase chain reaction (RT-PCR) that while alendronate fails to induce the expression of any of the BMPs tested, several BMPs are induced by PTH (1-34). The induction of the PTH (1-34)-inducible BMPs is blocked with simultaneous alendronate treatment. These data suggest that alendronate interferes with PTH (1-34)-induced BMP gene transcription and provides a possible basis for the antagonism observed between the two agents in increasing bone density.

Alendronate enhances antibiotic-impregnated bone grafts in the treatment of osteomyelitis

Bisphosphonates are systemic drugs. There is limited knowledge about their effects when applied locally and in osteomyelitis treatment. A prospective longitudinal randomised controlled study was designed in rat tibia to test the efficacy of local or systemically administered bisphosphonates for controlling the osteolytic reactions and possible effects on local infection control. Tibial osteomyelitis was induced in 72 Wistar albino rats with Staphylococcus aureus ATCC 25923 strain. Débridement was performed on all rats in all groups. No other treatment was given to the control group. Treatment groups received "plain bone grafts", "vancomycin-loaded bone grafts", "vancomycin-loaded bone grafts+systemic alendronate", "alendronate-impregnated bone grafts" and "vancomycin+alendronate-impregnated grafts". Study results were evaluated by swab cultures, radiology, quantitative computed tomography, dual-energy X-ray absorptiometry (DEXA) and histopathology. S. aureus was eradicated in groups II and IV by the sixth week. Diaphyseal widening, bone deformation, diaphyseal widening and osteolysis scores were significantly lower (p < 0.05), and bone mineral content, density measurements and DEXA scores were significantly higher (p = 0.001) with alendronate administration. Histology revealed marked osteoblastic activity. Local alendronate interfered with local infection control. Even though local alendronate at the given dose has stronger effects, the possible effects on the local inflammatory process needs to be clarified.

Missed opportunities in patients with osteoporosis and distal radius fractures

Low-energy wrist (distal radius) fractures are hallmarks of osteoporosis. Prompt diagnosis and treatment of osteoporosis reduce refracture rates. We retrospectively determined the type and frequency of osteoporosis-related interventions rendered to patients 50 years and older in the year after a wrist fragility fracture. In addition, we compared the rates of intervention between men and women. Data were collected from the computerized medical record of one military healthcare system. We identified 111 patients who sustained wrist fragility fractures between July and December 2002. Endocrinology referrals, dual-energy xray absorptiometry scans, and osteoporosis medication prescriptions in the year after their fracture were recorded. Overall, 28 patients (25%) were referred to endocrinology, 22 patients (20%) had a dual-energy xray absorptiometry scan, 33 patients (30%) were prescribed an approved medication for treatment of osteoporosis, and 52 patients (47%) were prescribed one of these medications and/or vitamin D and calcium. Sixty percent of patients received at least one intervention. All diagnostic and medical interventions were more likely ordered for women than men. Orthopaedic surgeons continue to miss opportunities to initiate diagnostic and therapeutic interventions for patients, especially men, presenting with fragility fractures.

Bisphosphonates: potential therapeutic agents for disease modification in osteoarthritis

Current treatments for osteoarthritis (OA) are mainly targeted towards providing short-term symptom relief. The focus in the development of disease-modifying drugs has been on therapies that modify cartilage directly. Recent research has highlighted the importance of subchondral bone as a target for therapeutic intervention and disease modification. At the subchondral level, affected joints have decreased bone mineral content and quality. In addition, increased bone turnover has been observed at levels similar to those in patients with osteoporosis. Consequently, the potential benefits of drugs that alter bone metabolism are being examined in this disease, in particular, the antiresorptive agents, bisphosphonates. Results from pre-clinical studies have shown promising results for these compounds. Although the mechanism of action remains unclear, comparative studies indicate that this activity may be unique to the specific structure of the bisphosphonate, rather than representative of a class effect. Clinical studies are now under way to determine the efficacy and safety of bisphosphonates which may offer new therapeutic options in the treatment of OA.