Healing Of Segmental Bone Defects Research Articles

A Novel Method to Assess Healing of Segmental Bone Defects using the Induced Membrane Technique.

Clinical concerns exist regarding the quality of bony consolidation in the context of the induced membrane technique. This study evaluates the clinical process of bone grafting in the second stage of induced membrane bone union in patients with tibial bone defects to infer the possibility of non-union and establish a reliable and effective evaluation method combined with computed tomography (CT) to assess fracture healing. Patients with tibial bone defects who underwent the induced membrane technique at our hospital between February 2017 and February 2020 were retrospectively analyzed. The Hounsfield unit (HU) values of the patients were evaluated at different times during the second stage of bone grafting. Bone healing at the boundary value of the 120 HU output threshold (-1024 HU-3071 HU) was directionally selected, and the changes in the growth volume of union (new bone volume [selected according to HU value]/bone defect volume) were compared with analyzing individual class bone union. Method 1 involved X-rays revealing that at least three of the four cortices were continuous and at least 2 mm thick, with the patient being pain free. For Method 2, new bone volume (selected according to HU value/bone defect volume) at the stage was compared with analyzing individual class healing. Receiver operating characteristic curve analysis was used for Methods 1 and 2. A total of 42 patients with a segmental bone defect with a mean age of 40.5 years (40.5 ± 8.3 years) were included. The relationship between bone graft volume and time variation was analyzed by single factor repeated variable analysis (F = 6.477, p = 0.016). Further, curve regression analysis showed that the change in bone graft volume over time presented a logarithmic curve pattern (Y = 0.563 + 0.086 × ln(X), Ra2 = 0.608, p = 0.041). ROC curve analysis showed that Method 2 is superior to Method 1 (AUC: 86.3% vs. 68.3%, p < 0.05). The induced membrane technique could be used to treat traumatic long bone defects, with fewer complications and a higher healing rate. The proposed imaging grading of HU (new bone volume/bone defect volume) can be used as a reference for the quality of bony consolidation with the induced membrane technique.

Tensile Stress-Activated and Exosome-Transferred YAP/TAZ-Notch Circuit Specifies Type H Endothelial Cell for Segmental Bone Regeneration.

The Ilizarov technique has been continuously innovated to utilize tensile stress (TS) for inducing a bone development-like regenerative process, aiming to achieve skeletal elongation and reconstruction. However, it remains uncertain whether this distraction osteogenesis (DO) process induced by TS involves the pivotal coupling of angiogenesis and osteogenesis mediated by type H endothelial cells (THECs). In this study, it is demonstrated that the Ilizarov technique induces the formation of a metaphysis-like architecture composed of THECs, leading to segmental bone regeneration during the DO process. Mechanistically, cell-matrix interactions-mediated activation of yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ) transcriptionally upregulates the expression of Notch1 and Delta-like ligand 4, which act as direct positive regulators of THECs phenotype, in bone marrow endothelial cells (BMECs) upon TS stimulation. Simultaneously, the Notch intracellular domain enhances YAP/TAZ activity by transcriptionally upregulating YAP expression and stabilizing TAZ protein, thus establishing the YAP/TAZ-Notch circuit. Additionally, TS-stimulated BMECs secrete exosomes enriched with vital molecules in this positive feedback pathway, which can be utilized to promote segmental bone defect healing, mimicking the therapeutic effects of Ilizarov technique. The findings advance the understanding of TS-induced segmental bone regeneration and establish the foundation for innovative biological therapeutic strategies aimed at activating THECs.

Hydrothermally treated coral scaffold promotes proliferation of mesenchymal stem cells and enhances segmental bone defect healing.

Introduction: Synthetic hydroxyapatite (HAp) scaffolds have shown promising therapeutic outcomes in both animals and patients. In this study, we aim to evaluate the chemical and physical phenotype, biocompatibility, and bone repair effects of hydrothermally treated coral with natural coral and synthetic HAp. Methods: The phase composition, surface pattern, 3D structures, and porosity of the scaffolds were characterized, and cell viability, proliferation, and osteogenic differentiation of mesenchymal stem cells (MSCs) after seeding onto the scaffold were determined. The scaffolds were implanted into rats to assess their bone repair effects using micro-CT analysis, mechanical testing, and histological staining. Results: The results showed that the phase composition, porous structure, and porosity of hydrothermally treated coral were comparable to pure HAp scaffold. While only the natural coral happens to be dominantly calcium carbonate. Higher cell proliferation and osteogenic differentiation potential were observed in the hydrothermally treated coral scaffold compared to natural coral and pure HAp. Histological results also showed increased new bone formation in the hydrothermally treated coral group. Discussion: Overall, our study suggests that hydrothermal modification enhances the cytocompatibility and therapeutic capacity of coral without altering its physical properties, showing superior effectiveness in bone repair to synthetic HAp.

Adrenomedullin has no effect on segmental bone defect healing but increases bone mineral density in rat model.

This study aimed to investigate the effect of adrenomedullin on the healing of the segmental bone defect in a rat model. Thirty-six Wistar rats were randomly divided into 6 groups based on follow-up periods and administered a dose of adrenomedullin hormone. In each group, bilaterally, a 2-mm bone defect was created at the diaphysis of the radius. Sodium chloride solution was administered to sham groups 3 times a week for 4 and 8 weeks intraperitoneally. Adrenomedullin was administered to the study groups 3 times a week: 15 μg-4 weeks, 15 μg-8 weeks, 30 μg-4 weeks, and 30 μg-8 weeks, respectively. After euthanasia, the segmental defects were evaluated by histomorphometric [new bone area (NBA)] and microtomographic [bone volume (BV), bone surface (BS), and bone mineral density (BMD)] analyses. Although the 4- and 8-week 15 μg administered study groups had higher NBA values than the other study and control groups, the histomorphometric analysis did not reveal any statistical difference between the control and study groups regarding NBA (P > .05). In microtomographic analysis, BV was higher in the 15 μg 4-week group than 30 μg 4-week group (296.9 vs. 208.5, P=.003), and BS was lower in the 30 μg 4-week group than in the 4-week control group (695.5 vs. 1334.7, P=.005), but overall, no significant difference was found between the control and study groups (P > .05). Despite these minor differences in histomorphometric and microtomographic criteria indicating new bone formation, the BMD values of the 15 μg 8-week study group showed a significant increase compared with the control group (P=.001, respectively). Adrenomedullin positively affected BMD at 15 μg, but this study could not show healing in the segmental defect site at different dose regimens. Further studies are needed to assess its effects on bone tissue trauma.

A Three-Dimensional Printed Polycaprolactone Scaffold Combined with Co-Axially Electrospun Vancomycin/Ceftazidime/Bone Morphological Protein-2 Sheath-Core Nanofibers for the Repair of Segmental Bone Defects During the Masquelet Procedure.

IntroductionMasquelet proposed a new solution for the healing of segmental bone defects, thus minimizing the disadvantages associated with traditional bone grafting. However, a major factor leading to the failure of this technique pertains to be the residual infection. Accordingly, we developed an antibiotic- and osteo-inductive agent-loaded composite scaffold to solve this problem.MethodsA mesh-like polycaprolactone scaffold was prepared using a lab-exploited solution-type three-dimensional printer, and hybrid sheath-core structured poly(lactic-co-glycolic-acid) nanofibers were fabricated using co-axial electrospinning technology. Vancomycin, ceftazidime, and bone morphological protein (BMP)-2 were employed. The in vitro and in vivo (rabbit fracture model) release patterns of applied agents from the composite scaffold were investigated.ResultsThe results revealed that the drug-eluting composite scaffold enabled the sustainable release of the medications for at least 30 days in vitro. Animal tests demonstrated that a high concentration of medications was maintained. Abundant growth factors were induced within the bioactive membrane stimulated by the applied scaffold. Finally, satisfactory bone healing potential was observed on radiological examination and biomechanical evaluation.DiscussionThe developed composite scaffold may facilitate bone healing by inducing bioactive membrane formation and yielding high concentrations of antibiotics and BMP-2 during the Masquelet procedure.

Clinical and Radiographic Effects of Bone Marrow Derived Mesenchymal Stem Cells Along with Local Insulin Therapy in Healing of Segmental Bone Defect in Diabetic Rabbits

The objective of present study was to investigate the efficacy of cultured allogenic bone marrow derived mesenchymal stem cell (BMMSCs) implant with insulin therapy for increasing osteosynthesis in bone gap defects in diabetic rabbits. Thirty six, clinically healthy New Zealand White rabbits were divided into four groups: A, B, C and D. Diabetes was induced experimentally in all rabbits, except group A. A 5 mm bone defect was created in right radii of all rabbits and following treatment was given: hydroxyapatite granules (group A and B), hydroxyapatite granules and insulin therapy (group C), cultured allogenic BMMSCs in hydroxyapatite scaffold and insulin therapy (group D). Clinical and radiographic parameters were recorded at days 0, 30, 60 and 90. It may be conducted that cultured allogenic bone marrow derived mesenchymal stem cells in hydroxyapatite scaffold along with local insulin therapy produces faster and better healing in alloxan-induced diabetic rabbits compared to healthy control, untreated diabetic and local insulin treated groups.

In vivo study of microarc oxidation coated Mg alloy as a substitute for bone defect repairing: Degradation behavior, mechanical properties, and bone response

Large segmental bone defect healing remains a great challenge in clinic. Limited by the source of autograft, bone graft substitute tends to be the research focus. In the present study, we propose a strategy by using microarc oxidation (MAO) coated magnesium scaffold as a large segmental bone graft substitute, utilizing its combination of strength, degradability, and controllable corrosion rate. Bare substrate, 10 μm and 20 μm thick MAO coated Mg scaffolds were implanted into ulna bone of New Zealand white rabbits, employing a 15 mm wide bone defect model. The biocompatibility and in vivo degradation of the implants, the bone defect healing response, and mechanical properties of the injured bone were investigated. The surface cytocompatibility evaluation results show that the MAO coated Mg are more suitable for cell proliferation. Micro-CT results show that abundant new bone formed and initially bridged the 15 mm gap at 8 weeks. Histological results indicate the newly formed bone was full of maturation at 12 weeks. Three point bending tests reveal that the injured bone possessed sufficient mechanical strength after 12 weeks. A 3-step in vivo degradation mechanism was proposed for the implants. In summary, we observed an actual trial of 15 mm wide bone defect healing where the newly formed bone bridged the bone gap at 8 weeks successfully. These data suggest a great potential of MAO coated magnesium to be a bone graft substitute.

Large scale segmental bone defect healing through the combined delivery of VEGF and BMP-2 from biofunctionalized cortical allografts.

Large scale cortical allografts suffer from poor incorporation and healing and often end in graft failure 5-10 years after implantation. To reduce these failures we have developed a growth-factor loaded cortical allograft capable of delivering one or two factors with a degree of temporal control and precision that permits the early release of one growth factor followed by the later and more sustained release of the other. We have loaded vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2 (BMP-2), both critical components of bone formation and repair, onto cortical long bone allografts such that the VEGF is released first and followed shortly by BMP-2. Coated and factor-loaded allografts were placed into a critical sized rat femoral segmental defect and allowed to heal for either 4 or 8 weeks. Healing at each time point was compared to allografts loaded with only BMP-2 and allografts containing no growth factors. Results indicate statistically significant increases in new bone formation from 4 to 8 weeks around allografts loaded with both VEGF and BMP-2 over allografts with no growth factor, suggesting that factor-loaded polymer-coated allografts delivering multiple factors with temporal precision may provide a new off-the-shelf tool to the orthopedic surgeon for management of large-scale orthopedic bone defects. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1002-1010, 2019.

Porous Particle-Reinforced Bioactive Gelatin Scaffold for Large Segmental Bone Defect Repairing.

Large segmental bone defect repairing remains a big challenge in clinics, and synthetic bone grafts suitable for this purpose are still highly demanded. In this article, hydrophilic composite scaffolds (bioactive hollow particle (BHP)-gel scaffold) composed of bioactive hollow nanoparticles and cross-linked gelatin have been developed. The bioactive nanoparticles have a porous structure as well as high specific surface area; thus, they interact strongly with gelatin to overcome the swelling problem that a hydrophilic polymer scaffold will usually face. With this combination, these BHP-gel scaffolds showed porous structure and mechanical properties similar to those of the cancellous bone. They also showed excellent bioactivity and cell growth promotion performance in vitro. The best of them, namely, 10BHP-gel scaffold, was evaluated in vivo on a rat femur model, where it was found that the 5 mm segmental bone defect almost healed with new bone tissue formed in 12 weeks and the scaffold itself degraded at the same time. Thus, 10BHP-gel scaffold may become a potential bone graft for large segmental bone defect healing in the future.

Subtypes of endothelial progenitor cells affect healing of segmental bone defects differently.

Treating fracture nonunion with endothelial progenitor cells (EPCs) is a promising approach. Nevertheless, the effect of different EPC-related cell populations remains unclear. In this study, we compared the therapeutic potential of early (E-EPCs) and late EPCs (L-EPCs). Male Fischer 344 rats were used for cell isolation and in vivo experiments. Bone marrow-derived E-EPCs and L-EPCs were kept in culture for seven to tendays and four weeks, respectively. For each treatment group, we seeded one million cells on a gelatin scaffold before implantation in a segmental defect created in a rat femur; control animals received a cell-free scaffold. Bone healing was monitored via radiographs for up to tenweeks after surgery. In vitro, secretion of vascular endothelial growth factor (VEGF) and bone morphogenetic protein (BMP)-2 was quantified by ELISA for both cell populations. Tube formation assays were also performed. Final radiographs showed complete (four out of five rats) or partial (one out of five rats) union with E-EPC treatment. In contrast, complete healing was achieved in only one of five animals after L-EPC implantation, while control treatment resulted in nonunion in all animals. In vitro, E-EPCs released more VEGF, but less BMP-2 than L-EPCs. In addition, L-EPCs formed longer and more mature tubules on basement membrane matrix than E-EPCs. However, co-culture with primary osteoblasts stimulated tubulogenesis of E-EPCs while inhibiting that of L-EPCs. We demonstrated that bone marrow-derived E-EPCs are a better alternative than L-EPCs for treatment of nonunion. We hypothesize that the expression profile of E-EPCs and their adaptation to the local environment contribute to superior bone healing.

Nano composites commonly used in medicine and veterinary

Nanocomposite in various fields were discussed and tested and show various results. Assessment of polycaprolacton (PCL) nanocomposite scaffold compared with hydroxyapatite (HA) on healing of segmental femur bone defect in rabbits. Assessment of tricalcium phosphate/collagen (TCP/collagene) nanocomposite scaffold compared with hydroxyapatite (HA) on healing of segmental femur bone defect in rabbits. Alteration in the trace minerals of cutaneous wounds of rabbits grafted with calciumsilvernanocomposite films Development of shampoo, soap and ointment formulated by green synthesised silver nanoparticles functionalised with antimicrobial plants oils in veterinary dermatology: treatment and prevention strategies. The impact of potential feed additive nanocomposite (AG,Cu,Fe,andMnDioxide) on eggs quality parameters of lying hens compared with metal salts. Biomimetic synthesis of bone-like nanocomposites using the self-organization mechanism of hydroxyapatite and collagen. Synthesis and Properties of Silicone Rubber/Organomontmorillonite Hybrid Nanocomposites). Self-healing hybrid nanocomposites consisting of bisphosphonatedhyaluronan and calcium phosphate nanoparticles.

The Effect of Surgical Technique and Spacer Texture on Bone Regeneration: A Caprine Study Using the Masquelet Technique.

The Masquelet-induced-membrane technique is a commonly used method for treating segmental bone defects. However, there are no established clinical standards for management of the induced membrane before grafting. Two clinically based theories were tested in a chronic caprine tibial defect model: (1) a textured spacer that increases the induced-membrane surface area will increase bone regeneration; and (2) surgical scraping to remove a thin tissue layer of the inner induced-membrane surface will enhance bone formation. Thirty-two skeletally mature female goats were assigned to four groups: smooth spacer with or without membrane scraping and textured spacer with or without membrane scraping. During an initial surgical procedure (unilateral, left tibia), a defect was created excising bone (5cm), periosteum (9cm), and muscle (10g). Segments initially were stabilized with an intramedullary rod and an antibiotic-impregnated polymethylmethacrylate spacer with a smooth or textured surface. Four weeks later, the spacer was removed and the induced-membrane was either scraped or left intact before bone grafting. Bone formation was assessed using micro-CT (total bone volume in 2.5-cm central defect region) as the primary outcome; radiographs and histologic analysis as secondary outcomes, with the reviewer blinded to the treatment groups of the samples being assessed 12weeks after grafting. All statistical tests were performed using a linear mixed effects model approach. Micro-CT analysis showed greater bone formation in defects with scraped induced membrane (mean, 3034.5mm3; median, 1928.0mm3; quartile [Q]1-Q3, 273.3-2921.1mm3) compared with defects with intact induced membrane (mean, 1709.5mm3; median, 473.8mm3; Q1-Q3, 132.2-1272.3mm3; p=0.034). There was no difference in bone formation between textured spacers (mean, 2405.5mm3; median, 772.7mm3; Q1-Q3, 195.9-2743.8mm3) and smooth spacers (mean, 2473.2mm3; median, 1143.6mm3; Q1-Q3, 230.2-451.1mm3; p=0.917). Scraping the induced-membrane surface to remove the innermost layer of the induced-membrane increased bone regeneration. A textured spacer that increased the induced-membrane surface area had no effect on bone regeneration. Scraping the induced membrane during the second stage of the Masquelet technique may be a rapid and simple means of improving healing of segmental bone defects, which needs to be confirmed clinically.

Hydrothermally converted marine coral scaffold promotes segmental bone defect healing in rats

Hydrothermally converted marine coral scaffold promotes segmental bone defect healing in rats

Effect of pentoxifylline on healing of segmental bone defects and angiogenesis.

The aim of this study was to determine the effect of pentoxifylline (PTX) on angiogenesis and the healing of a critical-sized segmental defect of the radius diaphysis in a rat model, using radiological and histological grading systems. The study included 24 female Sprague-Dawley rats (weight: 300±20 g) divided into 4 groups. A critical-sized segmental defect was created in the radius diaphysis in all rats. In Group 1, morcellized iliac crest autografts were used to fill the segmental bone defect. In Group 2, segmental bone defects were filled using morcellized iliac crest autografts, and 25 mg/kg/day PTX was applied intraperitoneally. In Group 3, the segmental bone defects were not filled, and in Group 4 the segmental bone defects were left unfilled, and an intraperitoneal (IP) dose of 25 mg/kg/day PTX was applied. Rats were sacrificed at postoperative Week 8, and defects were evaluated using radiographic, histological and immunohistochemical methods. There were significant differences between Group 1 and 2 according to radiological evaluation (p=0.003) and quality of union at the defect site (p=0.01). Union quality was higher in Group 4 than Group 3 (p=0.01). Cluster of differentiation 31 (CD31) and vascular endothelial growth factor (VEGF) levels were higher in Group 2 than in Groups 3 and 4. According to radiological and histological parameters, PTX appears to improve angiogenesis and healing of segmental cortical bone defects of the radius in a rat model.

Segmental Metadiaphyseal Humeral Bone Loss in Pediatric Trauma Patients

The management of posttraumatic bone loss is complicated and often requires complex reconstructive procedures. No options exist that are specific to the treatment of the growing skeleton that has intercalary bone loss. We have observed reconstitution of the humerus in 2 cases that have precluded extensive management. Two pediatric patients sustained traumatic injuries to the upper extremities, including humeral bone loss, and are presented after spontaneous reconstitution of the segmental bone loss. With treatment restricted to soft-tissue injury and bone stabilization with external fixation, both patients demonstrated radiographic healing of humeral segmental bone loss. Both patients were thought to have a partially intact periosteal sleeve. They have returned to sporting activities with mild loss of function. In certain pediatric injuries, spontaneous healing of segmental bone defects can occur. This response may obviate the need for complex, interventional procedures. Level IV-case series.

The effect of bone allografts combined with bone marrow stromal cells on the healing of segmental bone defects in a sheep model

BackgroundThe repair of large bone defects is a major orthopedic challenge because autologous bone grafts are not available in large amounts and because harvesting is often associated with donor-site morbidity. Considering that bone marrow stromal cells (BMSC) are responsible for the maintenance of bone turnover throughout life, we investigated bone repair at a site of a critically sized segmental defect in sheep tibia treated with BMSCs loaded onto allografts. The defect was created in the mid-portion of the tibial diaphysis of eight adult sheep, and the sheep were treated with ex-vivo expanded autologous BMSCs isolated from marrow aspirates and loaded onto cortical allografts (n = 4). The treated sheep were compared with control sheep that had been treated with cell-free allografts (n = 4) obtained from donors of the same breed as the receptor sheep.ResultsThe healing response was monitored by radiographs monthly and by computed tomography and histology at six, ten, fourteen, and eighteen weeks after surgery. For the cell-loaded allografts, union was established more rapidly at the interface between the host bone and the allograft, and the healing process was more conspicuous. Remodeling of the allograft was complete at 18 weeks in the cell-treated animals. Histologically, the marrow cavity was reestablished, with intertrabecular spaces being filled with adipose marrow and with evidence of focal hematopoiesis.ConclusionsAllografts cellularized with AOCs (allografts of osteoprogenitor cells) can generate great clinical outcomes to noncellularized allografts to consolidate, reshape, structurally and morphologically reconstruct bone and bone marrow in a relatively short period of time. These features make this strategy very attractive for clinical use in orthopedic bioengineering.

Extracting hydroxyapatite and its precursors from natural resources

Healing of segmental bone defects remain a difficult problem in orthopedic and trauma surgery. One reason for this difficulty is the limited availability of bone material to fill the defect and promote bone growth. Hydroxyapatite (HA) is a synthetic biomaterial, which is chemically similar to the mineral component of bones and hard tissues in mammals and, therefore, it can be used as a filler to replace damaged bone or as a coating on implants to promote bone in-growth into prosthetic implants when used in orthopedic, dental, and maxillofacial applications. HA is a stoichiometric material with a chemical composition of Ca10(PO4)6(OH)2, while a mineral component of bone is a non-stoichiometric HA with trace amounts of ions such as Na+, Zn2+, Mg2+, K+, Si2+, Ba2+, F−, CO32−, etc. This review looks at the progress being made to extract HA and its precursors containing trace amount of beneficial ions from biological resources like animal bones, eggshells, wood, algae, etc. Properties, such as particle size, morphology, stoichiometry, thermal stability, and the presence of trace ions are studied with respect to the starting material and recovery method used. This review also highlights the importance of extracting HA from natural resources and gives future directions to the researcher so that HA extracted from biological resources can be used clinically as a valuable biomaterial.

In vivo tracking of segmental bone defect healing reveals that callus patterning is related to early mechanical stimuli

This study addresses the hypothesis that callus formation, patterning, and mineralisation are impaired during the early phase of critical sized bone defect healing, and may relate to inter-fragmentary tissue strains within the bone defect area. Twenty four 12 week old Sprague Dawley rats were used for this study. They were divided into two groups defined by the femur bone defect size: (i) 1mm resulting in normal healing (NH), and (ii) a large sized 5mm defect resulting in critical healing (CH). Callus formation, patterning, and mineralisation kinetics in both groups were examined in the periosteal and osteotomy gap regions using a novel longitudinal study setup. Finite element analyses on µCT generated tomograms were used to determine inter-fragmentary tissue strain patterns and compared to callus formation and patterning over the course of time. Using a novel longitudinal study technique with µCT, in vivo tracking and computer simulation approaches, this study demonstrates that: (i) periosteal bone formation and patterning are significantly influenced by bone defect size as early as 2 weeks; (ii) osteotomy gap callus formation and patterning are influenced by bone defect size, and adapt towards a non-union in critical cases by deviating into a medullary formation route as early as 2 weeks after osteotomy; (iii) the new bone formation in the osteotomy gap enclosing the medullary cavity in the CH group is highly mineralised; (iv) inter-fragmentary strain patterns predicted during the very early soft callus tissue phase (less than 2 weeks) are concurrent with callus formation and patterning at later stages. In conclusion, bone defect size influences early onset of critical healing patterns.

Radiological evaluation of the effect of biphasic calcium phosphate scaffold (HA+TCP) with 5, 10 and 20 percentage of porosity on healing of segmental bone defect in rabbit radius

The objective of this study is to radiologically evaluate the effects of biphasic calcium phosphate scaffold with 5, 10 and 20 percentage of porosity on cortical bone repair in rabbits. In this study, 28 male white rabbits were examined. Rabbits were divided into four groups. After induction of general anesthesia, a segmental bone defect of 10 mm in length was created in the middle of the right radius shaft. In group A, the defect was stabilized with miniplate and 2 screws and left untreated. In groups B, C and D tricalcium phosphate scaffold mixed with hydroxyapatite (TCP+HA) with 5%, 10% and 20% porosity was used to fi ll the bone defect. Bone regeneration and HA+TCP scaffold resorption were assessed by X-ray at 1, 2 and 3 months after the surgery. In group A, 3 months after surgery, periosteal callus was not found but intercortical callus was observed. In groups B and C, 3 months after surgery medullary bridging callus and intercortical callus were found, periosteal callus was not found, TCP+HA scaffold were observed. In group D, 2 months after the surgery, medullary bridging callus and intercortical callus were found, 3 months later, periosteal callus was not found, most of scaffold had disappeared and were unclear and partial bone formation was recognized. Differences observed in radiological findings were significant between group A and groups B, C, D. Differences between groups B and C were not significant, but between group D and groups B and C were significant. The results of this study showed that TCP+HA scaffold is an osteoconductive and osteoinductive biomaterial. Scaffold of TCP+HA can increase the amount of newly formed bone and more rapid regeneration of bone defects. These results suggest TCP+HA scaffold may considerably be used in the treatment of cortical bone defect and other orthopaedic defects PCL (Tab. 2, Fig. 4, Ref. 20).

Tribute to Dr. Marshall Urist: Musculoskeletal Growth Factors: Editorial Comment

Tribute to Dr. Marshall Urist: Musculoskeletal Growth Factors: Editorial Comment