Stimulated Callus Formation Research Articles

Functional Outcome of Extra-Articular Distal Tibia Fracture Treated with Tibia Interlocking Nail: A Case Series

Background: Intramedullary interlocking nailing has emerged as one of the suitable management options for distal tibia fractures as it allows mechanical compression on weight-bearing, which stimulates bone healing. We studied 40 cases of extra-articular distal tibia fracture treated by intramedullary nailing. Methods: We retrospectively studied 40 patients of both sexes above the age of 18 years with closed fractures and grade 1, 2, and 3A compound fractures treated at SVP Hospital, Ahmedabad, India. Clinically, the fracture was considered to be united when the patient was completely pain-free. Patients were followed up at monthly intervals till union. At each follow-up, patients were assessed both clinically and radiographically, and details were recorded based on proforma. Results: The evaluation of the result was done using American Orthopedic Foot and Ankle Society (AOFAS) criteria. Thirty-three patients had excellent functional results, five had good functional results, and Two had fair functional results. In this study, 38 (95%) patients had radiological union within 24 weeks. Two patients had union after 28 weeks. Conclusion: Intramedullary nailing is a minimally invasive procedure that preserves the soft tissue and the fracture hematoma. It maintains the length, alignment, and rotation and allows micromotion at the fracture site on weight-bearing, which stimulates callus formation. It has a good functional outcome with gratifying results when used in extra-articular distal tibia fractures.

Mechanically compliant locking plates for diaphyseal fracture fixation: A biomechanical study.

Axial micromotion between bone fragments can stimulate callus formation and fracture healing. In this study, we propose a novel mechanically compliant locking plate which achieves up to 0.6 mm of interfragmentary motion as flexures machined into the plate elastically deflect under physiological load. We investigated the biomechanical performance of three compliant plate variations in comparison to rigid control plates with small and large working lengths in a comminuted bridge plating scenario using humeral diaphysis surrogates. Under static axial loading, average interfragmentary motion was 6 times larger at 100 N (0.38 vs. 0.05 mm) and nearly three times larger at 350 N (0.58 vs. 0.2 mm) for compliant plates than rigid plates, respectively. Compliant plates delivered between 2.5 and 3.4 times more symmetric interfragmentary motion than rigid plates (p < 0.01). The bi-phasic stiffness of compliant pates provided 74%-96% lower initial axial stiffness up to approximately 100 N (p < 0.01), after which compliant plate stiffness was similar to rigid plates with increased working length (p > 0.3). The strength to failure of compliant plates under dynamic loading was on average 48%-55% lower than rigid plate groups (p < 0.01); however, all plates survived cyclic fatigue loading of 100,000 cycles at 350 N. This work characterizes the improvement in interfragmentary motion and the reduction in strength to failure of compliant plates compared to control rigid plates. Compliant plates may offer potential in comminuted fracture healing due to their ability to deliver symmetric interfragmentary motion into the range known to stimulate callus formation while surviving moderate fatigue loading with no signs of failure.

Cytotoxicity of novel hybrid composite materials for making bone fracture plates

Bone fracture plates are usually made from steel or titanium, which are much stiffer than cortical bone. This may cause bone ‘stress shielding’ (i.e. bone resorption leading to plate loosening) and delayed fracture healing (i.e. fracture motion is less than needed to stimulate callus formation at the fracture). Thus, the authors previously designed, fabricated, and mechanically tested novel ‘hybrid’ composites made from inorganic and organic materials as potential bone fracture plates that are more flexible to reduce these negative effects. This is the first study to measure the cytotoxicity of these composites via the survival of rat cells. Cubes of carbon fiber/flax fiber/epoxy and glass fiber/flax fiber/epoxy had better cell survival vs. Kevlar fiber/flax fiber/epoxy (57% and 58% vs. 50%). Layers and powders made of carbon fiber/epoxy and glass fiber/epoxy had higher cell survival than Kevlar fiber/epoxy (96%–100% and 100% vs. 39%–90%). The presence of flax fibers usually decreased cell survival. Thus, carbon and glass fiber composites (with or without flax fibers), but not Kevlar fiber composites (with or without flax fibers), may potentially be used for bone fracture plates.

A Complete Micropropagation Protocol for Black-Leaved Zamioculcas zamiifolia (Lodd.) Engl. ‘Dowon’

Zamioculcas zamiifolia, a drought-resistant plant in the family Araceae, is a popular ornamental potted foliage plant originating from tropical east and subtropical southeast Africa. The growth and propagation rate of this species is low in conventional propagation methods. Therefore, the current study aimed at developing a complete in vitro propagation protocol of black-leaved Raven® ZZ plant (Z. zamiifolia ‘Dowon’)—a novelty on the floricultural market. In order to initiate an axenic culture, the disinfection of leaf explants was performed with sodium hypochlorite and mercury chloride. Next, leaf segments were cultured on the Murashige and Skoog (MS) medium with the addition of 6-benzyladenine (BA) and/or ɑ-naphthalene acetic acid (NAA) at various concentrations. The highest number of shoots (11) and leaves (22) per explant was obtained in a medium enriched with 2 mg·L−1 BA together with 0.5 mg·L−1 NAA. The maximum number of roots (3.33) was produced in microshoots cultured on the medium supplemented with 2 mg·L−1 NAA. On the other hand, the longest roots (2.66 cm) were produced on a medium containing 2 mg·L−1 NAA and 0.5 mg·L−1 BA. The combination of 0.5 mg·L−1 BA and 0.5 mg·L−1 NAA was most effective in stimulating callus formation (78.33%). Rooted plantlets were transferred to plastic pots filled with coco peat and acclimatized to ambient greenhouse conditions with an average 68.19% survival rate. This is the first report on a complete micropropagation protocol of black-leaved zamioculcas.

Determinants of the reproduction of Рrunus dulcis (Mill.) D.A.Webb. biotechnological methods

The purpose of the presented article is to establish the trophic and hormonal determinants of the ontogenesis of Prunus dulcis regenerants in vitro. One of the urgent problems in Ukraine is climate change, which reduces the level of achieving sustainable development and hinders humanity from both agroecological and food security. Such changes lead to the diversification of traditional agriculture. In Ukraine, almonds are a valuable, promising nut crop, thanks to which it is possible to diversify climate risks. Varieties of foreign selection with a long growing season and low winter hardiness are not suitable for our zone. Plants of four domestic varieties of almonds E5 Borozan, M41 Alex, Georgia, Louise (entered into the register in 2020) were involved in the study. One of the reliable methods for obtaining high-quality planting material, healthy from diseases, fast reproduction rates is microclonal reproduction. Therefore, modern nurseries switch to the production of planting material using biotechnological methods. Preparatory measures of mother plants of explant donors and decontamination increase the efficiency of work at the first stage of microclonal propagation. Primary explants are planted on media with a twice-reduced content of nutrients and a high content of cytokinins and gibberellins. Its success also depends on the selection of components, the pH of the nutrient medium (trophic determinants), and the interaction of exo-genous and endogenous hormones (hormonal determination.) The main trophic determinants are synthetic carbohydrates and mineral components added to artificial nutrient media. According to the Skoog-Miller rule, at the stage of multiplication, cytokinins predominate in the nutrient medium, and for root formation, their content decreases and the content of auxins decreases. Both auxins and cytokinins are added in high concentrations to stimulate callus formation. A systematic study of the features of the determinants of microclonal reproduction of almonds is relevant for the creation of MCR technologies. The lack or unavailability of one of the elements affects the plant object. Key words: microclonal reproduction, almonds in vitro, power elements, synthetic phytohormones.

Effectiveness and Biomechanical Analysis of the Ortho-Bridge System on Femoral Fracture Healing: A Retrospective Analysis

BackgroundAmong the surgical methods for femoral fractures, the Ortho-Bridge System (OBS) appears to heal fractures via an uncommon process. We compared its effectiveness and biomechanical aspects to those of a locking compression plate (LCP) and explained the healing process demonstrated by the OBS.MethodsEleven femoral shaft fracture cases treated with OBS between July 2017 and May 2020 were retrospectively reviewed. Clinical and radiographic data were collected during regular postoperative follow-up visits and assessed via the Harris Hip Score and Knee Society Score. We performed biomechanical experiments of OBS. We simulated different fracture conditions and selected appropriate screw holes at the fracture’s far and near segments. The OBS module was placed according to the position of LCP’s locking hole at both ends of the fracture; then, a static three-point bending test was performed.ResultsAll patients had contralateral callus growth with secondary fracture healing. Healing time was 3–5 months with excellent hip and knee function. When the key screw distance was 22–34 mm, the OBS was significantly less stiff than the LCP (P < 0.05). The stiffness of LCP and OBS decreased significantly when the key screw distance was 49–82 mm, with the LCP being slightly stronger (P < 0.05).ConclusionsFemoral shaft fracture treatment with OBS demonstrated secondary healing. When the distance between the key screws was 20–40 mm, the elasticity was higher in OBS than in LCP, possibly producing axial micro-motion to stimulate callus formation and promote fracture healing, which differ from the plate’s primary healing process.

Observation on role of bone marrow aspirate in the delayed union and non union of long bones

Background: Cells aspirated from bone marrow have been shown to provide stimulus for osteogenesis in animal experiments and in clinical evaluation of bone graft and bone substitutes. Despite this osteogenic characteristic, the clinical use of marrow as an osteogenic source has remained limited. The marrow is harvested by means of needle aspiration from the patient's pelvic bone and is then injected percutaneously at the nonunion site. This method offers the advantage of treating fracture-healing problems without operative exposure of either the donor or the recipient site.Aim: The purpose of this study was to ascertain the osteogenic potential of autologous bone marrow injection and its effectiveness in the management of delayed union and nonunion.Material and Methods: Autologous marrow injection was used to stimulate healing in 26 out of 34 patients were males. patients with delayed union and nonunion of fracture of the long bones This prospective study was done in Orthopaedic department of Darbhanga Medical College and Hospital in Laheriasarai, Darbhanga over a period of 2 years (2018 – 2020).Surgical Technique: Bone marrow aspirated from the iliac crest was injected at the fracture site.Results: Marrow stimulated callus formation sufficient to unite in delayed unions and nonunions immobilized with cast or intramedullary nails.Conclusion: Bone marrow injection was as effective as open autogenous grafting but with considerably less complications. Thus, the technique provides a reliable source of osteogenic stem cells with numerous advantages compared with standard open grafting techniques.

Total phenolic content, antioxidant and antimicrobial activities of seeds and callus of Trigonella foenum-graecum Linn.

Development of an efficient system for callus induction on different explants of fenugreek. Comparing phenolic, antioxidant and antimicrobial activities of seed and calli of different fenugreek explants. Fenugreek is a well-known medicinal plant for pharmaceutical and nutraceutical properties. For callus induction, three explants were used viz. hypocotyl, root, and cotyledons. The explants were cultured on MS medium supplemented with 2, 4-D, NAA and TDZ in different concentrations (0.5-6 mg/L). Antioxidant activity using DPPH and Folin-ciocalteu assays, and antimicrobial activity of calli and seed extracts were evaluated. Friable callus was successfully induced on all explants and by all PGRs except 2, 4-D which failed to stimulate callus formation on root explant. Root segment was the better explants in callus induction with maximum fresh weight 5.29 g with TDZ at 2 mg/L and highest callus index was 4.3 with TDZ at 0.5 mg/L. Hypocotyl callus showed the highest phenolic content (246.9 mg GAE/g DW) compared to root callus (243.5 mg GAE/g DW), seed (176.2 mg GAE/g DW) and then cotyledons callus (64.9 mg GAE/g DW) with the lowest value. On the other hand, seed exhibited 44.3% antioxidant activity compared to 34.7%, 24.3% and 16.7% recorded by cotyledons, hypocotyl, and root calli, respectively. Regarding antimicrobial activity of studied fenugreek extracts, hypocotyl callus exhibited the maximum zone of inhibition recorded (19 mm) against E. coli. Callus of fenugreek showed potential biological activities over seed-extract.

Enhancement of fracture healing after citrulline supplementation in mice.

Around 10 % of long bone fractures show inadequate bone healing resulting in non-union development. A deregulated arginine-citrulline-nitric oxide metabolism caused by a poor nutritional status of the patients is a risk factor for non-unions. Additionally, previous research in mice with a disrupted arginine to citrulline conversion showed delayed healing. The study hypothesis was that stimulating said metabolism could positively influence the healing process through promotion of collagen synthesis and angiogenesis. Adult wild-type mice underwent a femur osteotomy and plate-screw osteosynthesis. Mice were randomly divided into three groups and received daily oral supplementation of arginine, citrulline or 0.9 % saline (control). Body weight and food intake were measured daily. After 14 d, the mice were euthanised and femora collected. Callus formation was assessed by micro-computed tomography and concentrations of amino acids and enzymes in the femora were measured. Only citrulline-treated mice showed significantly increased bridging of the fracture gap when compared to control mice. Femur citrulline and ornithine concentrations were increased in citrulline-treated animals. qPCR showed significantly decreased expression of inflammatory markers, whereas increased expression of angiogenic and collagen-producing factors was observed in citrulline-treated mice. Although food intake did not show any difference between the three groups, animals treated with citrulline showed a weight gain of 0.3 g, compared with a 0.1 g decline in the control group. Daily oral citrulline supplementation stimulated callus formation and improved the inflammatory response, positively contributing to the enhanced healing response. Finally, the increased weight gain pointed toward a better post-operative recovery.

In vitro Callus Induction of Sipahutar Pineapple (Ananas comosus L.) from North Sumatra Indonesia.

Sipahutar pineapple (Ananas comosus L.) is a indigenous of pineapple grown in Sipahutar district, North Sumatra, Indonesia. Propagation of Sipahutar pineapple that being done traditionally is less effective, because the number of seeds that produced is very limited and requires a long time. Propagation through in vitro culture is an alternative solution to solve this problem. It is necessary to add plant growth regulator (PGR) to stimulate callus formation in Sipahutar pineapple explants (Ananas comosus L.). Callus induction of pineapple from Sipahutar was carried out by PGR treatment on MS medium. The purpose of this study was to determine the effect MS medium treatment with added dichlorophenoxyacetic acid (2,4-D) and benzyl amino purin (BAP) PGR on Sipahutar pineapple callus formation (Ananas comosus L.) with light and dark treatment. This callus induction research used a completely randomized design (CRD) with 2 factors, the first factor was treatment 2,4-D (0, 1, 2) ppm. The second factor is BAP (0, 0.5, 1) ppm. Nine combinations of treatments are obtained. Each combination of treatments is treated in both light and dark conditions. The parameters of this study were the percentage (%) of explants that formed callus, the time of callus formed, callus texture, callus biomass, callus surface height and callus surface area. Data were analyzed with two-way ANOVA, followed by Duncan Multiple Rate Test (DMRT). The study showed that the interaction between 2,4-D and BAP significantly affected the time of callus formed but 2,4-D and BAP did not significantly affect callus biomass, callus surface height and callus surface area. All explants can form callus, except explants without the addition of 2,4-D and BAP. The callus formed on 10 days after induction (DAI) and 12 DAI with the treatment of light and dark. The color of the produced callus were white, yellowish white, greenish white, brown, brownish yellow, brownish white, brownish green, yellowish green and greenish white. The callus formed is generally compact textures, except for explants which by giving 1 ppm 2,4-D produce friable callus.

Biomechanical considerations in the design of patient-specific fixation plates for the distal radius

Use of patient-specific fixation plates is promising in corrective osteotomy of the distal radius. So far, custom plates were mostly shaped to closely fit onto the bone surface and ensure accurate positioning of bone segments, however, without considering the biomechanical needs for bone healing. In this study, we investigated how custom plates can be optimized to stimulate callus formation under daily loading conditions. We calculated implant stress distributions, axial screw forces, and interfragmentary strains via finite element analysis (FEA) and compared these parameters for a corrective distal radius osteotomy model fixated by standard and custom plates. We then evaluated these parameters in a modified custom plate design with alternative screw configuration, plate size, and thickness on 5 radii models. Compared to initial design, in the modified custom plate, the maximum stress was reduced, especially under torsional load (− 31%). Under bending load, implants with 1.9-mm thickness induced an average strain (median = 2.14%, IQR = 0.2) in the recommended range (2–10%) to promote callus formation. Optimizing the plate shape, width, and thickness in order to keep the fixation stable while guaranteeing sufficient strain to enhance callus formation can be considered as a design criteria for future, less invasive, custom distal radius plates.Graphical abstractᅟ

JMJ30-mediated demethylation of H3K9me3 drives tissue identity changes to promote callus formation in Arabidopsis.

Plant somatic cells can be reprogrammed by invitro tissue culture methods, and massive genome-wide chromatin remodeling occurs, particularly during callus formation. Since callus tissue resembles root primordium, conversion of tissue identity is essentially required when leaf explants are used. Consistent with the fact that the differentiation state is defined by chromatin structure, which permits limited gene profiles, epigenetic changes underlie cellular reprogramming for changes to tissue identity. Although a histone methylation process suppressing leaf identity during leaf-to-callus transition has been demonstrated, the epigenetic factor involved in activation of root identity remains elusive. Here, we report that JUMONJI C DOMAIN-CONTAINING PROTEIN 30 (JMJ30) stimulates callus formation by promoting expression of a subset of LATERAL ORGAN BOUNDARIES-DOMAIN (LBD) genes that establish root primordia. The JMJ30 protein binds to promoters of the LBD16 and LBD29 genes along with AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 and activates LBD expression. Consistently, the JMJ30-deficient mutant displays reduced callus formation with low LBD transcript levels. The ARF-JMJ30 complex catalyzes the removal of methyl groups from H3K9me3, especially at the LBD16 and LBD29 loci to activate their expression during leaf-to-callus transition. Moreover, the ARF-JMJ30 complex further recruits ARABIDOPSIS TRITHORAX-RELATED 2 (ATXR2), which promotes deposition of H3K36me3 at the LBD16 and LBD29 promoters, and the tripartite complex ensures stable LBD activation during callus formation. These results indicate that the coordinated epigenetic modifications promote callus formation by establishing root primordium identity.

Discovery of a novel 2-(1H-pyrazolo[3,4-b]pyridin-1-yl)thiazole derivative as an EP1 receptor antagonist and in vivo studies in a bone fracture model

We describe a medicinal chemistry approach to the discovery of a novel EP1 antagonist exhibiting high potency and good pharmacokinetics. Our starting point is 1, an EP1 receptor antagonist that exhibits pharmacological efficacy in cystometry models following intravenous administration. Despite its good potency in vitro, the high lipophilicity of 1 is a concern in long-term in vivo studies. Further medicinal chemistry efforts identified 4 as an improved lead compound with good in vitro ADME profile applicable to long term in vivo studies. A rat fracture study was conducted with 4 for 4 weeks to validate its utility in bone fracture healing. The results suggest that this EP1 receptor antagonist stimulates callus formation and thus 4 has potential for enhancing fracture healing.

Bone morphogenetic protein 9 stimulates callus formation in osteoporotic rats during fracture healing.

Fracture healing involves the coordinated actions of multiple cytokines. Bone morphogenetic protein 9 (BMP9) is an important factor in bone formation. The present study aimed to investigate the osteogenic potential of bone marrow stem cells (BMSCs) in response to adenoviral (Ad)BMP9, and the early fracture repair properties of AdBMP9 in surgically-created fractures in osteoporotic rats. Alkaline phosphatase (ALP) activity was assayed and matrix mineralization was examined by Alizarin Red S staining. mRNA and protein expression levels of BMP9, runt-related transcription factor 2 (RUNX2) and type 1 collagen (COL-1) were detected in vitro and in vivo. Femoral bone mineral density was assessed for osteoporosis in ovariectomized rats. An open femora fracture was subsequently created, and gelatin sponges containing AdBMP9 were implanted. The femora were harvested for radiographical, micro-computed tomography, biomechanical and histological analysis 4 weeks later. BMP9 successfully increased ALP activity and induced mineralized nodule formation in BMSCs. BMP9 in gelatin sponges demonstrated marked effects on microstructural parameters and the biomechanical strength of bone callus. In addition, it upregulated the expression levels of RUNX2 and COL-1. AdBMP9 in gelatin sponges significantly mediated callus formation, and increased bone mass and strength in osteoporotic rats with femora fractures. The results of the present study suggested that BMP9 enhanced callus formation and maintained early mechanical stability during fracture healing in osteoporotic rats, implicating it as a potential novel therapeutic target for fracture healing.

Extra Corporeal Shock Wave – A New Wave of Therapy

AbstractExtracorporeal shock wave therapy (ESWT) has been enormously used in medical practice, especially for the management of various orthopedic and musculoskeletal disorders. Extracorporeal shock wave therapy has favorable effects on stimulating callus formation, inducing angiogenesis and bone regeneration and relieving pain. Studies also indicated that extra corporeal shock waves have a significant bactericidal effect on bone- and implant-associated infections. The present article reviews the various applications of extra corporeal shock wave therapy in the field of dentistry and the possibility of inculcating the useful properties of shock waves in improving the treatment outcome.

Control of the micromovements of a composite-material nail design: A finite element analysis

BackgroundIntramedullary nail fixation is the most accepted modality for stabilizing long bone midshaft fractures. The commercially used nails are fabricated from Stainless Steel or Titanium. Composite-materials (CM) mainly carbon-fiber reinforced polymers (CFRP) have been gaining more interest and popularity due to their properties, such as modulus of elasticity close to that of bone, increased fatigue strength, and radio-opacity to irradiation that permits a better visualization of the healing process. The use of CFRP instead of metals allows better control of different directional movements along a fracture site. The purpose of this analysis was to design a CM intramedullary nail to enable micromovements as depicted on a finite element analysis method. MethodsWe designed a three-dimentional femoral nail model. Three CFRP with different laminates arrangements, were included in the analysis. The finite element analysis involved applying vertical and horizontal loads on each of the designed and tested nails. ResultsThe nails permitted a transverse micromovement of 0.75mm for the 45° lay-up and 1.5mm for the 90° lay-up for the CM, 1.38mm for the Titanium and 0.74mm for the Stainless Steel nails. The recorded axial movements were 0.53mm for the 45° lay-up, 0.87mm for the 90° lay-up, 0.46mm for the unsymmetrical lay-up CM, 0.046 for the Titanium and 0.02 for the Stainless Steel nails. Overall, the simulations showed that nail transverse micromovements can be reduced by using 45° carbon fiber orientations. Similar results were observed with each metal nails. InterpretationWe found that nail micromovements can be controlled by changing the directional stiffness using different lay-up orientations. These results can be useful for predicting nail micromovements under specified loading conditions which are crucial for stimulating callus formation in the early stages of healing.

English

Carapa guianensis Aubl. (Meliaceae), known locally as andiroba, is a multi-use species from Amazonia. Andiroba oil is considered an important natural product in the Brazilian market, and international demand is increasing due to its cosmetic and pharmaceutical potential. C. guianensis trees produce seed irregularly over different harvest periods, leading to inconsistent oil production and difficulties with supply. No management plans or protocols have been developed for in vitro or clonal production of Carapa seedlings and the maintenance of genetic resources. The objective of this study was to assess the effect of growth regulators on explants (young leaves, old leaves and apical buds). Explants consisting of leaf segments 1 cm on a side were cultivated in MS medium with and without growth regulators. Evaluation was based on fresh and dry weight of the explants after 20 days. In the media with 2,4-dichlorophenoxyacetic acid (5, 15, 35 or 45 &micro;M), changes were observed in weight and explant appearance (callus). Bud breakage and development of shoots were achieved using 5 &micro;M of 6-benzylaminopurine. Overall, the results showed that 2,4-dichlorophenoxyacetic acid stimulates callus formation on andiroba foliar explants, while 6-benzylaminopurine was superior to thidiazuron for the initial development of shoots. &nbsp; Key words: Growth regulators, Carapa guianensis, in vitro, tissue culture, organogenesis.

Percutaneous autologous bone marrow injection as a substitute for operative grafting in delayed union and nonunion of long bone fractures

Background Cells aspirated from bone marrow have been shown to provide stimulus for osteogenesis in animal experiments and in clinical evaluation of bone graft and bone substitutes. Despite this osteogenic characteristic, the clinical use of marrow as an osteogenic source has remained limited. The marrow is harvested by means of needle aspiration from the patient's pelvic bone and is then injected percutaneously at the nonunion site. This method offers the advantage of treating fracture-healing problems without operative exposure of either the donor or the recipient site. Aim of the work The purpose of this study was to ascertain the osteogenic potential of autologous bone marrow injection and its effectiveness in the management of delayed union and nonunion. Patients and methods Autologous marrow injection was used to stimulate healing in 21 patients with delayed union and nonunion of fracture of the long bones. Of these 21 cases, two patients had fracture shaft femur, one had fracture shaft humerus, and 18 patients had tibial shaft fractures during the period from January 2008 to April 2010 at Tanta University Hospital. Surgical technique Bone marrow aspirated from the posterior iliac crest was injected at the fracture site two to three times with an interval of 3 weeks. Results Marrow stimulated callus formation sufficient to unite 18 of 21 cases of delayed unions and nonunions immobilized with cast or intramedullary nails. Conclusion Bone marrow injection was as effective as open autogenous grafting but with considerably less complications. Thus, the technique provides a reliable source of osteogenic stem cells with numerous advantages compared with standard open grafting techniques.

Low-Intensity Pulsed Ultrasound Therapy Stimulates Callus Formation between Host Femur and Cortical Onlay Strut Allograft

Cortical onlay strut allografting is a promising surgical option to reconstruct and reinforce the deficient femur in a hip arthroplasty. However, the union of the allograft to the host bone takes a long time. To accelerate the process of cortical onlay strut allograft healing, we studied the effects of low-intensity pulsed ultrasound (LIPUS) on callus formation. From 2 wk after the operation, LIPUS was given for 20 min/d at each end of the strut allograft. The LIPUS treatment group was assigned 14 allograft transplantations, while 21 control patients were treated without LIPUS. The LIPUS treatment group formed calluses and had complete bridging between the host femur and the allograft faster after operation (16.9 and 29.4 wk after operation, respectively) compared with the control group (40.7 and 82.0 wk after operation, respectively). Our findings showed that LIPUS stimulated bone bonding between the host femur and the cortical onlay strut allografts.

Biomechanical Analysis of Bone Healing at One-Plate and Double-Plate Fixation of Femoral Bone Fractures

The present paper present describes so-far unsolved issues of the biomechanics of the bone - plate stabiliser system functioning in a multi-plane system. The few available publications treat this question selectively and often generally. There are no reports which would provide data on the influence of the geometry of a Polfix type plate stabiliser system on the speed of the long bones synostosis process. Clinical practice shows that using an improperly selected fixation system and inappropriate biomechanical stabilisation conditions leads to an inappropriate course of the synostosis process. On the basis of distortion vector maps, the location of the system's rotation centre was determined. In the case of a one-plate fixation, its smaller rigidity and thus greater displacement in the fracture crack, makes it possible for rotation and lateral displacement to occur. This leads to shearing of the newly forming bone tissue. In the case of a two-plate fixation, the system's rotation centre is located in the fracture crack. This is the area where approximation of bone fractures takes place. The distribution scheme of the distortion vectors on the surface of the model shows that the system's rotation centre is located in the fracture crack, and axial approximation of the fixed fragments occurs in this area. Movements of such a type in the fracture crack stimulate callus formation.