A single bisphosphonate infusion does not accelerate fracture healing in high tibial osteotomies

Potential bioactive coating system for high-performance absorbable magnesium bone implants

Magnesium alloys are considered the most suitable absorbable metals for bone fracture fixation implants. The main challenge in absorbable magnesium alloys is their high corrosion/degradation rate that needs to be controlled. Various coatings have been applied to magnesium alloys to slow down their corrosion rates to match their corrosion rate to the regeneration rate of the bone fracture. In this review, a bioactive coating is proposed to slow down the corrosion rate of magnesium alloys and accelerate the bone fracture healing process. The main aim of the bioactive coatings is to enhance the direct attachment of living tissues and thereby facilitate osteoconduction. Hydroxyapatite, collagen type I, recombinant human bone morphogenetic proteins 2, simvastatin, zoledronate, and strontium are six bioactive agents that show high potential for developing a bioactive coating system for high-performance absorbable magnesium bone implants. In addition to coating, the substrate itself can be made bioactive by alloying magnesium with calcium, zinc, copper, and manganese that were found to promote bone regeneration.

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Bioactive-coated magnesium implant could accelerate bone fracture healing time to match with magnesium degradation.

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Hydroxyapatite, collagen type I, recombinant human bone morphogenetic proteins 2, simvastatin, zoledronate, and strontium are high potential bioactive coating materials.

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The incorporation of Ca, Zn, Cu, Sr, and Mn in Mg base-metal could further enhance bone formation.

Timing of osteoporosis therapies following fracture: the current status

In most patients, osteoporosis is diagnosed only after the occurrence of the first fragility fracture. It is of utmost importance to start osteoporosis medications immediately in these patients to prevent future fractures and also to reduce associated mortality and morbidity. There remains a hesitancy over initiating osteoporotic medications, specifically for antiresorptive agents like bisphosphonates following an acute fracture due to concern over their effect on fracture healing. The purpose of this review is to study the effect of the timing of initiation of different osteoporosis medications on healing after an acute fracture. Most of the human studies, including randomized control trials (RCTs), did not find any significant negative effect on fracture healing with early use of bisphosphonate after an acute fracture. Anabolic agents like teriparatide have shown either neutral or beneficial effects on fracture healing and thus can be started very early following any osteoporotic fracture. Although human studies on the early use of other osteoporosis medications like denosumab or strontium ranelate are very sparse in the literature, none of these medications have shown any evidence of delay in fracture healing. To summarize, among the commonly used anti-osteoporosis agents, both bisphosphonates and teriparatide are safe to be initiated in the early acute post-fracture period. Moreover, teriparatide has shown some evidence in favor of reducing fracture healing time.

Case Report: Reconstruction of a Large Maxillary Defect With an Engineered, Vascularized, Prefabricated Bone Graft

The reconstruction of complex midface defects is a challenging clinical scenario considering the high anatomical, functional, and aesthetic requirements. In this study, we proposed a surgical treatment to achieve improved oral rehabilitation and anatomical and functional reconstruction of a complex defect of the maxilla with a vascularized, engineered composite graft. The patient was a 39-year-old female, postoperative after left hemimaxillectomy for ameloblastic carcinoma in 2010 and tumor-free at the 5-year oncological follow-up. The left hemimaxillary defect was restored in a two-step approach. First, a composite graft was ectopically engineered using autologous stromal vascular fraction (SVF) cells seeded on an allogenic devitalized bone matrix. The resulting construct was further loaded with bone morphogenic protein-2 (BMP-2), wrapped within the latissimus dorsi muscle, and pedicled with an arteriovenous (AV) bundle. Subsequently, the prefabricated graft was orthotopically transferred into the defect site and revascularized through microvascular surgical techniques. The prefabricated graft contained vascularized bone tissue embedded within muscular tissue. Despite unexpected resorption, its orthotopic transfer enabled restoration of the orbital floor, separation of the oral and nasal cavities, and midface symmetry and allowed the patient to return to normal diet as well as to restore normal speech and swallowing function. These results remained stable for the entire follow-up period of 2 years. This clinical case demonstrates the safety and the feasibility of composite graft engineering for the treatment of complex maxillary defects. As compared to the current gold standard of autologous tissue transfer, this patient’s benefits included decreased donor site morbidity and improved oral rehabilitation. Bone resorption of the construct at the ectopic prefabrication site still needs to be further addressed to preserve the designed graft size and shape.

Intramedullary injury combined with osteoporosis therapeutics regulates targeted local osteogenesis

Bone marrow ablation prompts transient bone formation in nearly the entire medullary cavity before marrow regeneration occurs. Here, we establish a procedure to direct bone formation in a desired particular site within the medullary cavity for support of biomedical devices. Local intramedullary injury was performed in the tibiae of rats and parathyroid hormone (PTH), alendronate, or saline was administered. Newly generated bone in the medulla was assessed by micro-CT and histology. To evaluate the function of newly generated bone, animals received intramedullary injury in tibiae followed by daily PTH. At day-14, implants were placed in the endocortical bone and the bone response to the implants was assessed. The fate of newly generated bone was compared with and without implants. We found that neither intramedullary injury nor medication alone resulted in bone formation. However, when combined, substantial bone was generated locally inside the diaphyseal medulla. Newly formed bone disappeared without implant placement but was retained with implants. Bone was especially retained around and between the implants. This study found that local bone marrow disruption followed by PTH or alendronate generated substantial cancellous bone locally in the diaphyseal medulla. This approach offers promise as a tissue engineering tool in medicine and dentistry.

The Effect of Bisphosphonates on Fracture Healing Time and Changes in Bone Mass Density: A Meta-Analysis

BACKGROUND

Osteoporosis is a common complication of acute fracture, which can lead to fracture delayed union or other complications and resulting in poor fracture healing. Bisphosphate is a common anti-osteoporosis drug, but its application in fracture patients is still controversial because of its inhibitory effect on bone resorption.

METHOD

Studies were acquired from literature databases in accordance with established inclusion criteria. Standard mean difference (SMD) and 95% confidence intervals (Cls) were calculated to evaluate the effectiveness of the bisphosphonates treatment in fracture patients. Data analysis was conducted with the Review Manager 5.4.1 software.

RESULTS

A total of 16 studies involving 5022 patients obtained from selected databases were examined. As expected, bisphosphate had no significant effect on fracture healing time, but it could significantly increase BMD and prevent osteoporosis. Meanwhile, bisphosphate can inhibit both bone resorption and bone formation markers, resulting in low bone turnover state.

CONCLUSION

This meta-analysis showed that bisphosphonate have no significant effect on fracture healing time but they do increase the changes in BMD and reduce bone synthesis and resorption markers. Early application of bisphosphonates after injury in the appropriate patient population should be considered.

Adjuvant drug-assisted bone healing: Part III - Further strategies for local and systemic modulation

In this third in a series of reviews on adjuvant drug-assisted bone healing, further approaches aiming at influencing the healing process are discussed. Local and systemic modulation of bone metabolism is pursued with use of a number of drugs with completely different indications, which are characterized by a pleiotropic spectrum of action. These include drugs used to treat lipid disorders (HMG-CoA reductase inhibitors), hypertension (ACE inhibitors), osteoporosis (bisphosphonates), cancer (proteasome inhibitors) and others. Potential applications to enhance bone healing are discussed.

Different effects of Wnt/β-catenin activation and parathyroid hormone on diaphyseal and metaphyseal in the early phase of femur bone healing of mice

Parathyroid hormone (PTH) and agents related to the manipulation of Wnt/β-catenin signalling are two promising anabolic anti-osteoporotic therapies that have been shown to promote the healing of bone fractures. Now, it is widely accepted that cortical bone and trabecular bone are two different compartments, and should be treated as separate compartments in pathological processes, such as fracture healing. It is currently unknown whether PTH and the activation of β-catenin signalling would demonstrate different effects on cortical bone and trabecular bone healing. In the current study, single 0.6-mm cortex holes were made in the femur metaphysis and diaphysis of mice, and then, PTH application and β-catenin activation were used to observe the promoting effect on bone healing. The effects of β-catenin and PTH signalling on fracture healing were observed by X-ray and CT at 3, 6, and 14 days after fracture, and the levels of β-catenin were detected by RT-PCR assay, and the number of specific antigen-positive cells of BRDU, OCN, RUNX2 was counted by immunohistochemical staining. While β-catenin activation and PTH were found to demonstrate similar effects on accelerating metaphyseal bone healing, activation of β-catenin showed a more striking effect than PTH on promoting diaphyseal bone healing. These findings might be helpful for selecting proper medication to accelerate fracture healing of different bone compartments.

Negative effect of zoledronic acid on tendon-to-bone healing

Background and purpose - Outcome after ligament reconstruction or tendon repair depends on secure tendon-to-bone healing. Increased osteoclastic activity resulting in local bone loss may contribute to delayed healing of the tendon-bone interface. The objective of this study was to evaluate the effect of the bisphosphonate zoledronic acid (ZA) on tendon-to-bone healing. Methods - Wistar rats (n = 92) had their right Achilles tendon cut proximally, pulled through a bone tunnel in the distal tibia and sutured anteriorly. After 1 week animals were randomized to receive a single dose of ZA (0.1 mg/kg IV) or control. Healing was evaluated at 3 and 6 weeks by mechanical testing, dual-energy X-ray absorptiometry and histology including immunohistochemical staining of osteoclasts. Results - ZA treatment resulted in 19% (95% CI 5-33%) lower pullout strength and 43% (95% CI 14-72%) lower stiffness of the tendon-bone interface, compared with control (2-way ANOVA; p = 0.009, p = 0.007). Administration of ZA did not affect bone mineral density (BMD) or bone mineral content (BMC). Histological analyses did not reveal differences in callus formation or osteoclasts between the study groups. Interpretation - ZA reduced pullout strength and stiffness of the tendon-bone interface. The study does not provide support for ZA as adjuvant treatment in tendon-to-bone healing.

Effect of zoledronic acid on spinal fusion outcomes in an ovariectomized rat model of osteoporosis

To evaluate the effect of zoledronic acid (ZA) on spinal fusion in ovariectomized (OVX) rats. Female SD rats (n = 50) were OVX or sham-operated and randomized into five groups: Sham, OVX control, ZOL-20 (20 µg/kg), ZOL-100 (100 µg/kg), and ZOL-500 (500 µg/kg). Eight weeks after OVX, bilateral lumbar spinal fusion was performed using autologous iliac bone with ZA or saline according to the grouping. The lumbar spines were harvested at 8 weeks and subjected to radiographic, manual palpation, micro-computed tomographic (micro-CT), and histological analysis. The manual palpation result differed significantly only between the ZOL-500 (fused: partially fused: not fused, 9:0:0) and OVX control (4:2:3) (p < 0.05). The radiographic scales were also differed significantly only between these two groups. According to the micro-CT results, the bone volume fraction (BV/TV) were significantly higher in all ZA-treated groups (54.2%, 65.9%, and 73.6%) than OVX control (43.7%) (p < 0.01). At clinical dose or lower, ZA didn't alter the spinal fusion, but a higher dose increased the spinal fusion rate significantly. This study suggests ZA may have a positive effect on spinal fusion in the presence of osteoporosis, and spinal fusion surgery outcome is not likely to be altered by ZA at clinical dose.

Bisphosphonates and their influence on fracture healing: a systematic review

Bisphosphonates are commonly used in osteoporosis, but concerns have been raised about possible negative effects on fracture healing. We systematically reviewed the literature and found that bisphosphonates significantly prolong union times of distal radius fractures but not femoral fractures. The timing of bisphosphonate introduction does not affect fracture union time.

INTRODUCTION

Bisphosphonates are the most commonly prescribed drugs in patients suffering from and at higher risk of developing osteoporosis. However, concerns have been raised as to whether these drugs have a negative effect on fracture healing. The aim of this systematic review is to explore further these concerns.

METHODS

A literature review was performed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All relevant articles found via MEDLINE, Cochrane, CINAHL, EMBASE and Google Scholar were screened. Studies with information on bisphosphonates' effect on fracture healing in humans were included and systematically reviewed.

RESULTS

Patients with distal radius fractures on bisphosphonates had a significantly longer union time compared with controls, but not patients with femoral fractures. No correlation between timing of bisphosphonate introduction and union time for fractures was found. Although one study reported a higher humeral non-union associated with bisphosphonate introduction following the fracture, there was no evidence that bisphosphonate introduction, timing or dose resulted in a significant delay in union following other fractures.

CONCLUSIONS

This systematic review has shown that bisphosphonates significantly prolong union times of distal radius fractures. Some clinical findings are in contrast with preclinical studies highlighting the need to develop better animal models to study osteoporosis, treatment and fracture healing. There is also a need for more well-constructed studies looking at the clinical effect of bisphosphonate on fracture healing in a large number of patients. These robust studies need to look at union time and non-union rates as a function of duration and dose of different bisphosphonates in different upper and lower limb fractures.

Timing of the initiation of bisphosphonates after surgery for fracture healing: a systematic review and meta-analysis of randomized controlled trials

SUMMARY

We performed a systematic review and meta-analysis of randomized clinical trials. Early administration of bisphosphonates (BPs) after surgery did not appear to delay fracture healing time either radiologically or clinically. Furthermore, the anti-resorptive efficacy of BPs given immediately after surgical repair should positively affect the rate of subsequent fractures.

INTRODUCTION

Bisphosphonates (BPs) are widely used in the prophylaxis and treatment of osteoporosis. However, early administration of BPs after surgical repair of a fracture may limit the reserve capacity of bone to heal. The aim of this review and meta-analysis was to analyze the benefits and adverse effects of early administration of BPs and give recommendations regarding when BPs should be utilized.

METHODS

We identified randomized controlled trials comparing the early administration of BPs to placebo, delayed BP treatment, or no therapy in adult patients after surgery. The search was performed in PubMed, the Cochrane Library, and Embase.

RESULTS

Ten studies with 2888 patients were included. Four trials used alendronate, three trials used zoledronic, two trials used risedronate, and one trial used etidronate. Early administration of BPs was considered less than 3 months after surgery. Patients treated with BP therapy had no significant differences in radiological fracture healing times compared with patients in the control group (mean difference [MD] 0.47, 95% confidence interval [CI] -2.75 to 3.69). There were also no significant differences in the rate of delay or nonunion of fracture healing (odds ratio [OR] 0.98, 95% CI 0.64 to 1.50). However, the bone mineral density (BMD) of total hips did significantly improve after 12 months of treatment with BPs. And most bone turnover markers of patients in the study group were significantly decreased.

CONCLUSIONS

Early administration of BPs after surgery did not appear to delay fracture healing time either radiologically or clinically. Furthermore, according to the changes in BMD and bone turnover markers, the anti-resorptive efficacy of BPs given immediately after surgical repair should positively affect the rate of subsequent fractures.

Local drug delivery for enhancing fracture healing in osteoporotic bone

Fragility fractures can cause significant morbidity and mortality in patients with osteoporosis and inflict a considerable medical and socioeconomic burden. Moreover, treatment of an osteoporotic fracture is challenging due to the decreased strength of the surrounding bone and suboptimal healing capacity, predisposing both to fixation failure and non-union. Whereas a systemic osteoporosis treatment acts slowly, local release of osteogenic agents in osteoporotic fracture would act rapidly to increase bone strength and quality, as well as to reduce the bone healing period and prevent development of a problematic non-union. The identification of agents with potential to stimulate bone formation and improve implant fixation strength in osteoporotic bone has raised hope for the fast augmentation of osteoporotic fractures. Stimulation of bone formation by local delivery of growth factors is an approach already in clinical use for the treatment of non-unions, and could be utilized for osteoporotic fractures as well. Small molecules have also gained ground as stable and inexpensive compounds to enhance bone formation and tackle osteoporosis. The aim of this paper is to present the state of the art on local drug delivery in osteoporotic fractures. Advantages, disadvantages and underlying molecular mechanisms of different active species for local bone healing in osteoporotic bone are discussed. This review also identifies promising new candidate molecules and innovative approaches for the local drug delivery in osteoporotic bone.

Osteotomy for treating knee osteoarthritis

BACKGROUND

Patients with unicompartmental osteoarthritis of the knee can be treated with an osteotomy. The goal of an osteotomy is to unload the diseased compartment of the knee. This is the second update of the original review published in The Cochrane Library, Issue 1, 2005.

OBJECTIVES

To assess the benefits and harms of an osteotomy for treating patients with knee osteoarthritis, including the following main outcomes scores: treatment failure, pain and function scores, health-related quality of life, serious adverse events, mortality and reoperation rate.

SEARCH METHODS

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE (Current Contents, HealthSTAR) were searched until November 2013 for this second update.

SELECTION CRITERIA

Randomised and controlled clinical trials comparing an osteotomy with other treatments for patients with unicompartmental osteoarthritis of the knee.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted data and assessed risk of bias using the domains recommended in the 'Risk of bias' tool of The Cochrane Collaboration. The quality of the results was analysed by performing overall grading of evidence by outcome using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach.

MAIN RESULTS

Eight new studies were included in this update, for a total of 21 included studies involving 1065 people.In four studies, the randomised sequence was adequately generated and clearly described. In eight studies, allocation concealment was adequately generated and described. In four studies, the blinding procedures were sufficient. In six studies, incomplete outcome data were not adequately addressed. Furthermore, in 11 studies, the selective outcome reporting item was unclear because no study protocol was provided.Follow-up of studies comparing different osteotomy techniques was too short to measure treatment failure, which implicates revision to a knee arthroplasty.Four studies evaluated a closing wedge high tibial osteotomy (CW-HTO) with another high tibial osteotomy (aHTO). Based on these studies, the CW-HTO group had 1.8% (95% confidence interval (CI) -7.7% to 4.2%; low-quality evidence) more pain compared with the aHTO group; this finding was not statistically significant. Pooled function in the CW-HTO group was 0.5% (95% CI -3.8% to 2.8%; low-quality evidence) higher compared with the aHTO group; this finding was not statistically significant. No data on health-related quality of life and mortality were presented.Serious adverse events were reported in only four studies and were not significantly different (low-quality evidence) between groups. The reoperation rate were scored as early hardware removal because of pain and pin track infection due to the external fixator. Risk of reoperation was 2.6 (95% CI 1.5 to 4.5; low-quality evidence) times higher in the aHTO group compared with the CW-HTO group, and this finding was statistically significant.The quality of evidence for most outcomes comparing different osteotomy techniques was downgraded to low because of the numbers of available studies, the numbers of participants and limitations in design.Two studies compared high tibial osteotomy versus unicompartmental knee replacement. Treatment failure and pain and function scores were not different between groups after a mean follow-up of 7.5 years. The osteotomy group reported more adverse events when compared with the unicompartmental knee replacement group, but the difference was not statistically significant. No data on health-related quality of life and mortality were presented.No study compared an osteotomy versus conservative treatment.Ten included studies compared differences in perioperative or postoperative conditions after high tibial osteotomy. In most of these studies, no statistically significant differences in outcomes were noted between groups.

AUTHORS' CONCLUSIONS

The conclusion of this update did not change: Valgus high tibial osteotomy reduces pain and improves knee function in patients with medial compartmental osteoarthritis of the knee. However, this conclusion is based on within-group comparisons, not on non-operative controls. No evidence suggests differences between different osteotomy techniques. No evidence shows whether an osteotomy is more effective than alternative surgical treatment such as unicompartmental knee replacement or non-operative treatment. So far, the results of this updated review do not justify a conclusion on benefit of specific high tibial osteotomy technique for knee osteoarthritis.

Do bisphosphonates affect bone healing? A meta-analysis of randomized controlled trials

Background

Whether bisphosphonates affect indirect bone healing is still unclear.

Method

We carried out a comprehensive search strategy. Only randomized controlled trials were included. Two reviewers independently assessed methodological qualities and extracted outcome data. Analysis was performed with RevMan 5.2.

Results

Eight eligible randomized controlled trials with 2,508 patients were included. Meta-analysis results showed that no statistically significant differences were founded in indirect bone healing in short time (within 3 months) (relative risk (RR) 1.40, relative the control group; 95% CI 0.36 to 5.49) and in long-term (more than 12 months) postoperation (RR 1.0; 95% CI 0.98 to 1.02) between bisphosphonates infusion groups and control groups. There were no statistically significant differences of indirect bone healing between early and delay bisphosphonates administration groups. Bisphosphonates infusion after lumbar infusion surgery could promote bone healing and shorten fusion time in 6 months postoperation (RR 1.35; 95% CI 1.11 to 1.66).

Conclusion

There was no clinically detectable delay to fracture healing via external callus formation following bisphosphonates treatment. Considering the benefit aspects of bisphosphonates for osteoporosis treatment, we recommend bisphosphonates infusion after fracture fixation surgery and lumbar fusion surgery.

Matrix metalloproteinase-driven endochondral fracture union proceeds independently of osteoclast activity

As new insights into the complexities of endochondral fracture repair emerge, the temporal role of osteoclast activity remains ambiguous. With numerous antiresorptive agents available to treat bone disease, understanding their impact on bone repair is vital. Further, in light of recent work suggesting osteoclast activity may not be necessary during early endochondral fracture union, we hypothesize instead a pivotal role of matrix metalloproteinase (MMP) secreting cells in driving this process. Although the role of MMPs in fracture healing has been examined, no directly comparative experiments exist. We examined a number of antiresorptive treatments to either block osteoclast activity, including the potent bisphosphonates zoledronic acid (ZA) and clodronate (CLOD), which work via differing mechanisms, or antagonize osteoclastogenesis with recombinant OPG (HuOPG-Fc), comparing these directly to an inhibitor of MMP activity (MMI270). Endochondral ossification to union occurred normally in all antiresorptive groups. In contrast, MMP inhibition greatly impaired endochondral union, significantly delaying cartilage callus removal. MMP inhibition also produced smaller, denser hard calluses. Hard callus remodeling was, as expected, delayed with ZA, CLOD, and OPG treatment at 4 and 6 weeks, resulting in larger, more mineralized calluses at 6 weeks. As a result of reduced hard callus turnover, bone formation was reduced with antiresorptive agents at these time points. These results confirm that the achievement of endochondral fracture union occurs independently of osteoclast activity. Alternatively, MMP secretion by invading cells is obligatory to endochondral union. This study provides new insight into cellular contributions to bone repair and may abate concerns regarding antiresorptive therapies impeding initial fracture union.

Healing of the bone with anti-fracture drugs

INTRODUCTION

Fracture healing is a complex process that leads to the restoration of tissue integrity through bone repair and represents a unique physiological characteristic of bone. Developing a better understanding of a fracture is essential to plan best noninvasive treatment for the patient. In osteoporosis, the patient who suffers of a fragility fracture is recommended to initiate a treatment with compounds active in preventing other low-energy skeletal trauma. Pharmaceutical industries are developing controlled clinical trials aiming to evaluate the capability of osteoporosis drugs to accelerate fracture healing.

AREAS COVERED

In preparing this review, a search was made with key words encompassing 'osteoporosis anti-fracture drugs and bone repair/healing', 'antiresorptives and bone repair/healing', 'bone-forming agents and bone repair/healing', and 'osteoporosis/anti-fracture drugs in fractures'. The results published in the area of the use of registered anti-fracture drugs to improve fracture repair and the efforts made to recommend measures for clinical outcomes in fracture healing acceleration are described in this report.

EXPERT OPINION

At present, the use of systemic pharmacological agents active to improve fracture healing by the clinicians is controversial and clinicians and scientists must do a better job in determining the methods of assessment for fracture healing.

The relation between zoledronic acid infusion and interbody fusion in patients undergoing transforaminal lumbar interbody fusion surgery

BACKGROUND

Zoledronic acid (ZOL) has been shown to significantly increase bone mineral density and to decrease the incidence of osteoporotic fractures. However, its safety when used after lumbar interbody fusion surgery remains unclear. We sought to determine whether ZOL infusion 3 days after transforaminal lumbar interbody fusion (TLIF) affects the risk of nonunion.

METHODS

This was a randomized, double-blind, placebo-controlled trial involving subjects who underwent TLIF surgery. Eighty-two subjects (≥50 years of age) were randomly assigned to receive either 5 mg intravenous ZOL (N=41) or placebo (N=41) 3 days after surgery. Each patient received a lumbar computed tomography scan 6 months and 12 months postoperatively. We evaluated interbody fusion using the multiplanar reconstruction technique. Clinical outcome was evaluated with the Oswestry Disability Index. Bone turnover markers (amino terminal propeptides of type I collagen and C-telopeptide of type I collagen) were measured to investigate the biological effects of ZOL on spinal fusion.

RESULTS

In the ZOL group, 7 levels (11.5%) exhibited non-union; in the placebo group, 9 levels (14.5%) exhibited nonunion at 12 months postoperatively. This difference was not statistically significant (P=0.82). The difference in ODI scores between two groups was not statistically significant at any of the follow-up times. However, ZOL decreased bone turnover markers significantly.

CONCLUSIONS

There was no association between ZOL treatment and nonunion of the lumbar spinal bone. Thus, undergoing lumbar interbody fusion surgery is not a valid reason to suspend or avoid treatment with ZOL.