The role of rigid skeletal fixation in bone-graft augmentation of the craniofacial skeleton

The type of fixation (rigid skeletal vs. wire) was assessed against embryologic origin (membranous vs. endochondral) and recipient site (depository vs. resorptive) as variables affecting inlay and onlay bone-graft survival in 20 mature dogs. Wet weight and volume measurements were made at operation and at sacrifice (16 weeks). The results were as follows: (1) Rigid skeletal fixation increased bone-graft volume survival over wire fixation (p less than 0.05). (2) Fixation (i.e., rigid skeletal) and embryologic origin (i.e., membranous) were equal determinants of bone-graft volume survival (p less than 0.001); the recipient site was not significant for onlay bone graft survival. (3) Embryologic origin was the only significant determinant of weight survival (p less than 0.001). (4) Inlay bone grafts demonstrated greater weight and volume survival than onlay bone grafts (p less than 0.05). (5) Histologic and microradiographic studies demonstrated bony union of bone grafts fixed with rigid skeletal fixation, while fibrous union predominated in bone grafts fixed with wire technique.     

A comparative analysis of the microarchitecture of cortical membranous and cortical endochondral onlay bone grafts in the craniofacial skeleton

Previous work in this laboratory established that an onlay bone graft's survival is determined primarily by its relative cortical and cancellous composition rather than its embryologic origin. A volumetric analysis of external bone graft resorption, however, does not explain the internal microarchitectural changes that may be occurring as these grafts become incorporated. To expand the knowledge of bone graft dynamics beyond volumetric parameters, a better understanding of the internal processes of bone graft remodeling is needed. In this comparative study of cortical onlay bone graft microarchitecture, the authors propose to show that cortical onlay bone grafts undergo measurable internal microarchitectural changes as they become incorporated into the surrounding craniofacial skeleton. In addition, the authors propose to further demonstrate similarities between the internal microarchitecture of cortical onlay bone grafts of different embryologic origin over time. Twenty-five adult New Zealand White rabbits were used for this study. They were divided into two groups of eight animals and one group of nine. The groups were killed at 3, 8, and 16 weeks. Cortical membranous and endochondral bone grafts were placed subperiosteally onto each rabbit's cranium. In addition, five ungrafted cortical endochondral and membranous bone specimens were used as controls. Microcomputed tomography (MCT) scanning and histomorphometric analysis were performed on all of the specimens to obtain detailed information regarding the microarchitecture of the cortical bone grafts. The parameters of bone volume fraction, bone surface area to volume, mean trabecular number, and anisotropy were used to give quantitative information about a bone's micro-organization. The results showed that there is no statistically significant difference between the cortical endochondral and the cortical membranous bone grafts for bone volume fraction, bone surface to volume, mean trabecular number, and anisotropy measurements for all time points. There were, however, statistically significant differences when comparing the control and 3-week groups to the 16-week group for all parameters. The advanced MCT technology and histomorphometric techniques proved to be effective in providing a qualitative and quantitative ultrastructural comparison of cortical endochondral and membranous onlay bone grafts over time. In this study, a statistically significant change in the internal microarchitecture of cortical onlay bone grafts of different embryologic origins was seen as they were remodeled and resorbed at all time points. Specifically, the onlay cortical bone grafts developed a less dense, more trabecular, and less organized internal ultrastructure. In addition, no difference in the three-dimensional ultrastructure of cortical endochondral and membranous bone was found. These results challenge some of the currently accepted theories of bone-graft dynamics and may eventually lead to a change in the way clinicians approach bone-graft selection for craniofacial surgery.     

Fixation effects on membranous and endochondral onlay bone graft revascularization and bone deposition.

This paper investigates the relationship between bone resorption, the process of bone revascularization, and graft fixation. Vital staining techniques and microangiography were used to study the extent of graft revascularization of fixed and nonfixed endochondral (rib) and membranous (skull) onlay bone grafts in 20 adult sheep mandibles bilaterally. This assessment was carried out at 2 and 20 weeks postoperatively. Sequential fluorochrome staining was performed to examine the pattern of new bone deposition. Fixation was achieved using the lagscrew technique. At 2 weeks, membranous bone demonstrated a greater area of graft revascularization if fixed than if the graft was not fixed. The opposite result was seen for endochondral grafts, where nonfixed grafts showed a greater area of revascularization than fixed grafts. At 20 weeks, all bone that was present was fully vascularized. The inconsistencies in the results on the relationship between fixation and revascularization for membranous and endochondral grafts in the early stages of healing (2 weeks) suggest that although revascularization is a necessary precondition for bone resorption and deposition, biomechanical and structural factors may be a more satisfactory explanation for the differences observed in the maintenance of bony volume.     

Fixation effects on membranous and endochondral onlay bone-graft resorption

Difficulties arise in the prediction of maintenance of graft volume over time when bone grafts are used for facial contour reconstruction. We hypothesize that graft fixation will decrease movement and lead to decreased resorption. Fixed and nonfixed endochondral (rib) and membranous (skull) onlay bone grafts measuring 30 X 10 X 4 mm were grafted to the mandible bilaterally in 10 adult sheep. Fixation was achieved using the lag-screw technique. Volume measurements using caliper technique were made 20 weeks postoperatively. The volume of graft present at 20 weeks was significantly greater for the fixed bone grafts (p less than 0.001): fixed membranous, 85.9 percent; fixed endochondral, 76.2 percent; nonfixed membranous, 55 percent; and nonfixed endochondral, 16.6 percent. The results are explained using biomechanical theories related to the effects of strain. At present, it is suggested by this study that when onlay bone grafts are stabilized, improved results with respect to graft resorption can be expected.     

Nasal reconstruction with full-thickness cranial bone grafts and rigid internal skeleton fixation through a coronal incision

The use of iliac and rib bone as onlay grafts to the nasal dorsum often fails because endochondral grafts resorb unpredictably. Membranous cranial bone grafts are less likely to resorb, especially when used with rigid internal fixation techniques. However, when split, they are often too thin and can be difficult to contour. Full-thickness cranial bone grafts were used to achieve nasal augmentation in 26 patients with end-stage nasal skeleton deficiency. All procedures were carried out using only a coronal incision. Grafts were harvested through a craniotomy, carved meticulously, and secured rigidly with miniplates or bicortical screws. Donor sites were reconstructed with split cranial grafts, leaving an intact cranial vault. No graft was lost to infection, and there was no significant donor-site morbidity. In carefully selected patients this method of full-thickness cranial bone graft reconstruction yields good results.     

Volume maintenance of inlay bone grafts in the craniofacial skeleton

Although the clinical use of inlay bone grafts is widespread in craniofacial surgery, the dynamics of inlay bone grafting to the craniofacial skeleton have never been well characterized. Previous work demonstrated that volume maintenance of bone grafts in the onlay position is a consequence of their microarchitectural features, rather than their embryological origins. The purpose of this study was to investigate whether the properties determining the volume maintenance of bone grafts in the onlay position in the craniofacial skeleton could be extended to bone grafts in the inlay position. It was hypothesized that volume maintenance of an inlay bone graft could be better explained on the basis of the microarchitectural features of the graft (cortical versus cancellous composition), rather than its embryological origin (membranous versus endochondral), and that the primary determinant of bone graft behavior is the interaction between the microarchitectural features of the bone graft and the local mechanical environment in which the bone graft is placed. Cortical and cancellous bone grafts were harvested from the iliac crest (endochondral origin) of 25 New Zealand white rabbits, and cortical bone was harvested from the mandible (membranous origin) of each rabbit. Four 7-mm trephine holes were made in the cranium of each rabbit, posterior to the coronal suture. Each defect was filled with endochondral cortical bone, endochondral cancellous bone, or membranous cortical bone or was left as an ungrafted control specimen. Animals were killed at 3, 8, or 16 weeks. Crania were subjected to micro-computed tomographic and histological assessments. Micro-computed tomographic analysis demonstrated significant increases in actual bone volume from time 0 to the time of death for all types of grafts. Cortical bone demonstrated significant increases in space-occupying volume at all time points. By 16 weeks, no statistically significant difference in either the actual bone volume or the space-occupying volume according to graft type could be detected. There was no resorption of the inlay bone grafts; in fact, all bone types exhibited increased volume. Cancellous bone demonstrated the greatest capacity to increase actual bone volume. All bone graft types seemed to reach a steady-state bone volume, as if controlled by a local regulator. The regulator is likely the local mechanical environment in which the grafts were placed, as corroborated by the findings that the bone grafts seemed to recapitulate the characteristics of the bone in which they were placed, rather than maintaining their native characteristics.     

Revascularization of cranial versus iliac crest bone grafts in the rat

Full-thickness cranial (membranous) and split-thickness iliac crest (endochondral) onlay bone grafts were placed subperiosteally without fixation onto the snout (membranous) and tibia (endochondral) in 30 rats. The animals had been divided into three equal groups in which the bone grafts had been demineralized, autoclaved, or used fresh. Recipient sites were harvested at 7 and 14 days at the snout and 14 days at the tibia, and revascularization was studied utilizing silicone rubber injection and a gridcounting technique. Endochondral grafts were found to have quantitatively greater revascularization than membranous grafts in all three groups at both sites (p less than 0.005). There was generally no statistically significant difference in revascularization between fresh and demineralized grafts, but vessel ingrowth was significantly decreased in autoclaved implants as compared with fresh grafts. Differences in graft architecture are theorized to account for the disparity in revascularization in endochondral and membranous grafts. Angiogenic and chemotactic factors are thought to play a role in the similarities and differences in revascularization among fresh, demineralized, and autoclaved bone.     

Growth and survival of vascularized and nonvascularized membranous bone: an experimental study

Although nonvascularized membranous bone grafts to the craniofacial skeleton demonstrate improved survival over similar grafts of endochondral origin, the comparative fate of vascularized membranous grafts is unknown. It is also unknown whether onlay membranous bone grafts in immature animals have the ability to grow. To examine these questions, a model was developed in New Zealand white rabbits in which a segment of the zygomatic arch was transferred to the subjacent mandible as either a vascularized or nonvascularized transfer. At harvest 16 weeks later, residual graft volume and bone architecture were analyzed. Results demonstrate no improved survival for vascularized membranous grafts in adult animals (n = 7), while in the immature animals (n = 6), growth of the vascularized bone transfers was documented. We conclude that in the majority of instances in craniofacial reconstruction, nonvascularized onlay membranous grafts are to be preferred. Specific instances for the use of vascularized transfers will be discussed.     

Craniofacial onlay bone grafting: a prospective evaluation of graft morphology, orientation, and embryonic origin

A prospective study using 46 young adult New Zealand rabbits was designed to evaluate onlay bone grafts to the craniofacial skeleton with respect to embryonic origin (membranous or endochondral), gross morphology (unicortical or bicortical), and orientation (cortex-to-bed relationship). Quantitative and qualitative data were analyzed and contrasted at both periods of evaluation (1.5 and 3.0 months). The embryonic origin of onlay bone grafts to the rabbit snout is significantly correlated with graft surface area, volume, weight, and recipient bed union for up to 3 months postoperatively. Over this interval, membranous bone (calvaria) grafts either persist in their entirety or increase, whereas endochondral bone (iliac) grafts resorb. Neither the number of cortices (unicortical or bicortical) nor the orientation of unicortical grafts (cortex-to-bed relationship) affected graft fate regardless of embryonic origin. Bone density remained unaltered during both resorption and deposition. Osteogenesis, demonstrated by serial fluorochrome markers, occurs in both membranous and endochondral bone grafts. Histologically, bone grafts of membranous and endochondral origin differ greatly in their cortical to cancellous diploe ratios and architectural configuration. We hypothesize that the differences found are related to the three-dimensional osseous architecture rather than to the embryonic origin of bone per se.     

The early revascularization of membranous bone

The experimental finding that membranous onlay bone grafts maintain volume and viability to a greater extent than do endochondral grafts may be related to the more rapid vascularization of membranous bone. Microangiographic techniques were used to study the rates of vascularization of membranous and endochondral bone grafts in adult white New Zealand rabbits at 1, 3, 7, 14, and 21 days after bone grafting. Vascularization patterns were quantified microscopically using a modified point-counting technique. At 3 days, membranous bone grafts demonstrated vessel ingrowth from both soft tissue and host bone. Little ingrowth was seen in endochondral grafts. By day 7, 2.5 vessels per square were identified entering membranous grafts, while an average of 0.6 vessels per square were counted for endochondral bone grafts. At day 14, there was an average of greater than 20 vessels per square for membranous grafts versus 1.8 for their endochondral counterparts. At 21 days, the endochondral grafts demonstrated persistent avascular central areas not seen in membranous grafts. Membranous onlay bone grafts in the rabbit are more rapidly vascularized than endochondral grafts. This factor may affect the greater volume maintenance seen in experimental membranous grafts.     

Long-term remodeling of vascularized and nonvascularized onlay bone grafts: a macroscopic and microscopic analysis

The present study was performed to compare vascularized and nonvascularized onlay bone grafts to investigate the potential effect of graft-to-recipient bed orientation on long-term bone remodeling and changes in thickness and microarchitectural patterns of remodeling within the bone grafts. In two groups of 10 rabbits each, bone grafts were raised bilaterally from the supraorbital processes and placed subperiosteally on the zygomatic arch. The bone grafts were oriented parallel to the zygomatic arch on one side and perpendicular to the arch on the contralateral side. In the first group, vascularized bone grafts were transferred based on the auricularis anterior muscle, and in the second group nonvascularized bone grafts were transferred. Fluorochrome markers were injected during the last 3 months of animal survival, and animals were killed either 6 or 12 months postoperatively. The nonvascularized augmented zygoma showed no significant change in thickness 6 months after bone graft placement and a significant decrease in thickness 1 year after graft placement (p < 0.01). The vascularized augmented zygoma showed a slight but statistically significant decrease in thickness 6 months after graft placement (p < 0.003), with no significant difference relative to its initial thickness 1 year after graft placement. In animals killed 6 months after bone graft placement, both the rate of remodeling and the bone deposition rate measured during the last 3 months of survival were significantly higher in the vascularized bone grafts compared with their nonvascularized counterparts (p < 0.02). By 1 year postoperatively, there were no significant differences in thickness, mineral apposition rate, or osteon density between bone grafts oriented perpendicular and parallel to the zygomatic arch. These findings indicate that the vascularity of a bone graft has a significant effect on long-term thickness and histomorphometric parameters of bone remodeling, whereas the direction of placement of a subperiosteal graft relative to the recipient bed has minimal effect on these parameters. In vascularized bone grafts, both bone remodeling and deposition are accelerated during the initial period following graft placement. Continued bone deposition renders vascularized grafts better suited for the long-term maintenance of thickness and contour relative to nonvascularized grafts.     

Cyclooxygenase-2 inhibition does not impair block bone grafts healing in rabbit model

Success of alveolar reconstructions using onlay autogenous block bone grafts depends on their adequate integration to the recipient bed influenced by a number of local molecules. Considering the fundamental role of cyclooxygenase (COX-2) in bone repair, the aim of this study was to analyze the effect of its inhibition in the integration of endochondral (EC) iliac crest, and intramembranous (IM) calvaria bone grafts. Thirty-two rabbits were divided into 4 groups: Calvaria Control (CC) and Iliac Control—treated with oral 0.9 % saline solution, and Calvarial-NSAID (C-NSAID) and Iliac-NSAID (I-NSAID) groups—treated with oral 6 mg/Kg non-steroidal anti-inflammatory drug etoricoxib. After 7, 14, 30 and 60 days the animals were euthanized and the specimens removed for histological, histomorphometric and immunohistochemistry analysis. At day 60, a tight integration of IM blocks could be seen with the presence of remodeling bone, whereas integration of EC grafts was mainly observed at the edges of the grafts. A significant higher percentage of bone matrix in the interface region of the CC grafts in comparison to C-NSAID only at day 14, whereas no differences were detected comparing the EC grafts. No differences were observed in Runx-2 and vascular endothelial growth factor (VEGF) immunolabeling when comparing CC and C-NSAID groups, while a significant weaker Runx-2 and VEGF labeling was detected in I-NSAID group at day 60. Although some influence was detected in osteogenesis, it is concluded that drug induced inhibition of COX-2 does not impair onlay bone grafts’ healing of both embryologic origins in rabbits.     

Electrical stimulation of onlay bone grafts

An animal model was developed to determine the ability of capacitively coupled electrical fields to enhance onlay bone graft survival in the craniofacial skeleton. Fifteen male New Zealand white rabbits were divided into control and stimulated groups. Blocks of iliac bone were transplanted as onlay grafts to the mandibular rami. In all animals a capacitor apparatus was attached externally over the right mandibular ramus; however, a 5-V peak-to-peak sinusoidal signal was applied only in the stimulated group. The experimental period was 6 weeks, with a total of 30 days of constant stimulation. Graft resorption in the stimulated animals was decreased a total of 24.8 percent (p less than 0.001). There appeared to be a trend toward decreased graft resorption caused by the apparatus alone, although this was not statistically significant. The electric field alone decreased resorption by 11.5 percent (p less than 0.05). No distinguishing features were demonstrated by fluorescent vital stains or routine histology.     

Bone graft survival in expanded skin

The effect of tissue expansion on iliac bone graft (onlay) survival was studied on the skulls of 35 New Zealand white rabbits. Wet bone weights at the time of grafting and at sacrifice in control animals (group I) were compared to three experimental groups. Histologic sections of the developing and resolving pseudosheath and skin envelope were performed. A self-inflating 5-mil-thick silicone expander was used for soft-tissue expansion over the rabbit snout. Bone grafts were subsequently placed in this site. Elliptical snout excision without expansion (group II) demonstrated no statistically significant difference in bone graft survival when compared to controls (group I) (p = 0.350). Full tissue expansion followed by immediate bone grafting (group III) within the pseudosheath cavity likewise demonstrated no statistically significant difference in bone graft survival when compared to controls (group I) (p = 0.500); however, when full tissue expansion was followed by delayed (2 weeks) bone grafting to allow for resolution of the giant cell inflammatory reaction of the pseudosheath (group IV), a statistically significant increased bone graft survival was achieved (p less than 0.001). The study demonstrates that the increased vascularity in the pseudosheath and in the expanded soft-tissue envelope significantly increased bone graft survival only when bone grafting was delayed.     

Cantilever nasal bone grafting with miniscrew fixation

A technique of rigid miniscrew fixation of cantilever nasal bone grafts is described. This produces stable, predictable nasal contour and tip projection without significant bone graft resorption.     

Growth potential in onlay bone grafts: a comparison of vascularized and free calvarial bone and suture bone grafts

Vascularized bone grafts are characterized by a viable cell population with osteogenic potential. These features suggest that continued growth can be anticipated following vascularized membranous bone transfer in a growing craniofacial skeleton. The present paper compares the potential for appositional bone growth in vascularized and free calvarial onlay bone grafts. In seven 8-week-old beagles, growth was assessed by direct caliper measurements of graft dimensions intraoperatively and 16 weeks postoperatively. Vascularized grafts demonstrated a 50 to 60 percent increase in size in all dimensions compared to 10 to 20 percent growth in free grafts (p less than 0.01). Microradiography revealed preservation of calvarial bony architecture and minimal resorption in vascularized grafts, while triple-fluorochrome labeling confirmed subperiosteal appositional bone formation. Free grafts were characterized by significant resorption and a delay in subperiosteal bone formation.     

Effects of rhBMP-2 and osteopromotive membranes on experimental bone grafting.

A problem with using autogeneic bone for onlay grafting is its degree of incorporation and volumetric persistence. This study explored whether improved graft volumetric maintenance can be achieved by recombinant human bone morphogenetic protein-2 (rhBMP-2) and whether a combination of rhBMP-2 and osteopromotive membranes is advantageous in this respect. Unicortico-cancellous bone grafts were positioned below the temporal muscle bilaterally in 48 adult Lewis rats. The recipient bone was ground, and the grafted area was randomly treated according to one of eight different alternatives. Two doses of rhBMP-2 (4 microg/80 microl or 32 microg/80 microl buffer) in a collagenous carrier were tested, with or without coverage with expanded polytetrafluoroethylene membranes. As controls, membrane and carrier, alone or in combination, and onlay grafts only were used. The results were evaluated after 4 and 20 weeks by routine histologic examination and immunohistochemical labeling for various bone and cartilage matrix proteins. After 4 weeks, rhBMP-2-treated grafts showed complete integration, whereas for controls, only the membrane-alone group attained incorporation after 20 weeks. The combined treatment with high-dose rhBMP-2 and membrane demonstrated, as compared with the remaining rhBMP-2 groups, pronounced bone formation and less graft resorption, resulting in maintained or increased graft size. This was observed after 4 weeks, and the result remained at 20 weeks. Treatment with high-dose rhBMP-2 without membrane placement, in contrast, resulted in extensive resorption and graft size reduction at 20 weeks. Control groups showed less success in graft size persistence. It was concluded that a combination of high-dose rhBMP-2 and osteopromotive membranes had a synergistic effect, leading to rapid, complete graft integration and size maintenance. In the absence of a membrane, the protein seemed to accelerate the remodeling of the graft.     

Effect of bone graft characteristics on the mechanical behavior of the lumbar spine

There is little information about the influence of bone graft size, position and elasticity on the mechanical behavior of the lumbar spine. Intersegmental motion, intradiscal pressure and stresses in the lumbar spine were calculated using a three-dimensional, nonlinear finite element model which included an internal spinal fixation device and a bone graft. Cross-sectional area, position, and elastic modulus of the graft were varied in this study. Bone grafts, especially very stiff ones, increase stresses on adjacent endplates. Though larger grafts lead to less contact pressure, it is difficult to judge the quality of different bone graft positions. In general, ventral flexion results in lower maximum contact pressure than lateral bending. There is always little intersegmental rotation in the bridged region compared with that of an intact spine.A larger graft with low stiffness should be favored from a mechanical point of view. Patients should avoid lateral bending of the upper body shortly after surgery.     

Effect of isolation of periosteum and dura on the healing of rabbit calvarial inlay bone grafts

Little is understood about the role of the recipient site in the revascularization and incorporation of autogenous inlay bone grafts in the craniofacial skeleton. Clinical experience demonstrates that secondary complex cranial vault reconstruction performed with scarred avascular dura or poor soft-tissue coverage may undergo significant resorption, thus compromising the aesthetic outcome. This study was designed to determine the effect of isolating autogenous orthotopic inlay calvarial bone grafts from the surrounding dura and/or periosteum on graft revascularization, healing, and volume maintenance in the adult rabbit. Adult rabbits were randomized into four groups (n = 10 per group); in each rabbit, the authors created a circular, 15-mm in diameter, full-thickness cranial defect followed by reconstruction with an autogenous calvarial bone graft, which was replaced orthotopically and held with microplate fixation. Silicone sheeting (0.5 mm thickness) was used to isolate the dura (group II), the periosteum (group II), or both dura and periosteum (group IV) from the graft interface. No silicone was placed in group I. Animals were killed 10 weeks postoperatively, and calvaria were harvested to assess graft surface area, morphology, quantitative histology, fluorochrome staining, and revascularization. Grafts isolated from both the dura and periosteum exhibited significant decreases in total bone (cortical and trabecular) surface area, blood vessel count, and interface healing compared with nonisolated control grafts. Isolation of either the dura or periosteum significantly (p < 0.05) decreased blood vessel count but had no significant effect on interface healing. Isolation of the dura alone was associated with a significant (p < 0.05) decrease in graft cross-sectional surface area and dural cortical thickness compared with nonisolated control grafts, but this effect was not observed when the periosteum alone was isolated. Quantitative histology performed 10 weeks after surgery indicated that graft isolation was associated with increased marrow fibrosis and necrosis compared with nonisolated controls; it also demonstrated evidence of increased activity in bone remodeling (osteoblast and osteocyte count, new trabecular bone, and surface resorption). Triple fluorochrome staining suggested increased bone turnover in the nonisolated grafts compared with isolated grafts at 1 and 5 weeks postoperatively. This study demonstrates that isolating a rabbit calvarial inlay autogenous bone graft from the dura and/or periosteum results in significantly (p < 0.05) decreased revascularization, interface healing, and cross-sectional areas of amount of mature bone compared with nonisolated control grafts 10 weeks after surgery. At this time point, histologic examination demonstrates a paradoxical increase in bone remodeling in isolated bone grafts compared with controls. It is possible that the inhibition of revascularization results in a delayed onset of the remodeling phase of graft incorporation. However, in the model studied, it is not known whether the quantitative histologic and morphometric parameters measured in these isolated grafts exhibit a "catch-up" phenomenon at time points beyond 10 weeks after surgery. The results of this study emphasize the importance of a healthy recipient site in the healing and incorporation of calvarial bone grafts but stress the need for further investigation at later time points.     

椎间植骨粒体积对腰椎滑脱融合内固定术融合效果的影响

目的:探讨在腰椎后路植骨融合手术中,椎间植骨粒的体积对手术效果的影响。方法:回顾性分析我院2012年5月-2013年9月采用腰椎后路植骨融合术的75例患者的临床资料,根据患者手术中椎间植骨粒体积不同分为A组(小体积组,5粒/cm3)、B组(中体积组,11粒/cm3)以及C组(大体积组,23粒/cm3)。分析三组患者的植骨粒体积、植骨融合率以及手术效果。结果:三组患者植骨粒体积比较,差异具有统计学意义(P0.05);椎间植骨总体积比较,差异无统计学意义(P0.05)。与术前比较,三组术后ODI指数及VAS评分明显下降,差异具有统计学意义(P0.05);但三组间比较,差异无统计学意义(P0.05)。B组植骨融合率高于A组及C组,而A组高于C组,组间比较,差异均具有统计学意义(P0.05)。手术后各组椎体滑脱程度与术前相比得到明显改善(P0.05)。结论:腰椎滑脱内固定术中应用中等体积植骨粒可明显提高椎体间融合率。