Callus Thickness Research Articles

Investigation of the effects of inflammatory and metabolic factors on fracture union in head trauma and long bone fractures

Background/Aim: Fractures are the most common form of trauma in current orthopedic practice. Although studies have shed light on the relationship between the factors affecting the healing process after fracture, this process is still not fully understood. In this study, we aimed to investigate the changes in serum biomediator levels and fracture healing in different trauma patterns, such as head trauma (HT), long bone fracture (LBF), a combination of HT + LBF injury (CI), and in different time points of the healing period.
 Methods: Forty Wistar rats were included in the study and divided into five groups. Group 1, the donor group, included rats with HT; Group 2 included rats with LBFs who were administered the serum taken from rats in Group 1; Group 3 included the rats with isolated LBFs; and Group 4 the rats with CI. Group 5 comprised the control rats. An experimental closed HT and fracture model was applied to rats. The rats in Groups 2, 3 and 4 were sacrificed on the 10th, 20th, and 30th days. The biomediator levels in the serum taken after sacrification were studied, while closed femoral fracture models were examined radiologically.
 Results: Statistically significant differences were found among the groups regarding radiological scores on the 10th, 20th, and 30th days. On Day 10, Group 2a had significantly higher scores than Group 3a (P=0.03), and Group 3a had lower scores than Group 4a (P=0.01). On Day 20, Group 2b had significantly higher scores than Group 3b (P=0.004) but lower than Group 4b (P=0.03). On Day 30, Group 2c had significantly higher scores than Group 3c but lower than Group 4c (P=0.001). The mean Ca, TGF beta 1, beta-catenin, IL-10, IL-17A, TNF alpha, CRP, Wnt-16, ALP, GH, PTH, IL-1 beta, IL-6, and IL-22 levels were significantly different among the groups (P<0.05). No significant difference was observed in the biomediator levels among the groups at different time points of the healing period.
 Conclusion: We concluded that inflammatory cytokines (IL-1 beta, IL-6, IL-17A, IL-17F, IL-23, and TNF alpha) were elevated in the early period in individuals with isolated head trauma and that this effect could be transferred to other individuals by serum transfer. On the other hand, the negative relationship between the IL-10 level, which is a negative modulator in fracture union, and callus thickness was significant. Our study contributes by providing a molecular description of the positive union effect transferred between individuals by serum. We believe our findings will play a significant role in developing new therapeutic agents for fracture healing.

Correlation of Bone Strength in an Animal Model (Rabbit) After Fracture and During the Period of Fixation with a Titanium Micro Plate

Abstract The period of bone healing after trauma goes through certain physiological processes. In situations where a bone fracture occurs, our intention is to surgically position in an appropriate morpho-anatomical position. For osteosynthesis we used vipla wire and micro plates with corresponding screws. The aim of our research was to evaluate the optimal time for the removal of the osteosynthetic material, fracture site biomechanical stability, and measurement of the callus thickness. For this research ten 4 months old rabbits with right leg femur fracture were used. Osteosynthesis was done with titanium micro plates, corresponding screws and vipla wire. Experimental animals were observed through the post-operative period at the first and seventh postoperative day and there on at 2, 4, 6, 9, 12 weeks. Further additional fixation was needed in one of the rabbits in the second week. The postoperative period provided us information about the optimal moment for the removal of titanium micro plates. It showed that over a period of six weeks, the bone had almost all normal biomechanical properties. Significantly greater strength and rigidity of the recovered femur were obtained after 12 weeks. Micro plates that were removed after 4, 6 or 9 weeks, did not need furhter fixation and therefore fixation was not applied, compared to those placed during the 12 weeks. X Ray evaluation provided us with follow up results of fracture healing. The results suggest that it is acceptable to remove titanium micro plates after a period of healing, that is, after the formation of the callus and bridging of the fracture gap and diastasis with newly formed bone.

PENAMBAHAN IAA DAN BAP TERHADAP PERTUMBUHAN KALUS EKSPLAN DAUN ANGGREK Coelogyne pandurata Lindl.

Orchid Coelogyne pandurata Lindl or black orchid is one of the endemic orchid from borneo Island. This orchid flower who have an unique that is have a green cephal and black labellum. Naturally propagation have a small chance of succsess so it needs to be done culture in vitro. One of the culture ways is use explaned leaf for making callus’s growth. Callus growth can spurred on with auxin (IAA) and cytokinins (BAP). A balanced blend of auxin concetracion and cytokinins are expected can touch callus growth up. The purpose of this research is to know addition effect of IAA and BAP for Orchid C. pandurata Lindl’s growthed and know interaction the best IAA and BAP for Orchid Coelogyne pandurata Lindl’s growth.
 The method of research done by experiment with the completely randomized used factorial pattern. Factor 1 concentracion IAA with 4 level : 0, 1, 2, 3 mg/L. and the next factor, concentracion of BAP with 4 level : 0, 1 , 2, 3 mg/L, so there are 48 experimental units. Observed parameter is : when the callus appears, the data obtained in the analysis with ANOVA and carried out DMRT test with believeable level 95%.
 The result of the research showed giving interaction of IAA and BAP can give a affect callus growth of Orchid C pandurata Lindl. The interaction effect is on the callus appearance, callus thickness, and callus live percentage. As well as being able to spur the development of callus in a proliferative directon. While giving IAA personally could stimulate callus thickening. The best interaction in callus’s growth explan the orchid flower is A2B2 (IAA 2 mg/L and BAP 2 mg/L) and A2B3 (IAA 2 mg/L and BAP 3 mg/L).

Computational modeling of human bone fracture healing affected by different conditions of initial healing stage

BackgroundBone healing process includes four phases: inflammatory response, soft callus formation, hard callus development, and remodeling. Mechanobiological models have been used to investigate the role of various mechanical and biological factors on bone healing. However, the effects of initial healing phase, which includes the inflammatory stage, the granulation tissue formation, and the initial callus formation during the first few days post-fracture, are generally neglected in such studies.MethodsIn this study, we developed a finite-element-based model to simulate different levels of diffusion coefficient for mesenchymal stem cell (MSC) migration, Young’s modulus of granulation tissue, callus thickness and interfragmentary gap size to understand the modulatory effects of these initial phase parameters on bone healing.ResultsThe results quantified how faster MSC migration, stiffer granulation tissue, thicker callus, and smaller interfragmentary gap enhanced healing to some extent. However, after a certain threshold, a state of saturation was reached for MSC migration rate, granulation tissue stiffness, and callus thickness. Therefore, a parametric study was performed to verify that the callus formed at the initial phase, in agreement with experimental observations, has an ideal range of geometry and material properties to have the most efficient healing time.ConclusionsFindings from this paper quantified the effects of the initial healing phase on healing outcome to better understand the biological and mechanobiological mechanisms and their utilization in the design and optimization of treatment strategies. It is also demonstrated through a simulation that for fractures, where bone segments are in close proximity, callus development is not required. This finding is consistent with the concepts of primary and secondary bone healing.

Foot callus thickness does not trade off protection for tactile sensitivity during walking.

Until relatively recently, humans, similar to other animals, were habitually barefoot. Therefore, the soles of our feet were the only direct contact between the body and the ground when walking. There is indirect evidence that footwear such as sandals and moccasins were first invented within the past 40thousand years1, the oldest recovered footwear dates to eightthousand years ago2 and inexpensive shoes with cushioned heels were not developed until the Industrial Revolution3. Because calluses-thickened and hardened areas of the epidermal layer of the skin-are the evolutionary solution to protecting the foot, we wondered whether they differ from shoes in maintaining tactile sensitivity during walking, especially at initial foot contact, to improve safety on surfaces that can be slippery, abrasive or otherwise injurious or uncomfortable. Here we show that, as expected, people from Kenya and the United States who frequently walk barefoot have thicker and harder calluses than those who typically use footwear. However, in contrast to shoes, callus thickness does not trade-off protection, measured as hardness and stiffness, for the ability to perceive tactile stimuli at frequencies experienced during walking. Additionally, unlike cushioned footwear, callus thickness does not affect how hard the feet strike the ground during walking, as indicated by impact forces. Along with providing protection and comfort at the cost of tactile sensitivity, cushioned footwear also lowers rates of loading at impact but increases force impulses, with unknown effects on the skeleton that merit future study.

Response of Pineapple Callus (Ananas comosus Merr.) through In-Vitro Colchicines Treatment

Pineapple Plant ( Ananas comosus (L.) Merr) is a fruit plant that has a high economic value. Increased variety of pineapple preparations lead to increased demand for pineapple fruit. Polyploidation is one way to increase the varieties using colchicine. This study aims to know the pineapple explants of callus response after being treated by colchicine using in vitro method. This research used Group Randomized Design (GRD) which variations concentration of Colchicine 0%, 0.01%, 0.05%, and 0.1%. Parameters were observed to response and thickness of callus of pineapple explants. Data were analyzed using F test and DMRT test in which significance level of 5% with SPSS 17 program. The results showed that pineapple plant explant able to respond colchicine concentration marked with thicker callus. The best colchicine treatment to induce pineapple explants callus was concentration 0.1% of colchicine.

Integrated management of the charcoal disease by silviculture, chemical and biological methods in forest parks

ABSTRACTBiscogniauxia mediterranea (De Not.) Kuntze, is a widespread fungus, causes outbreaks of Charcoal disease on cork oak and dieback thousands oak trees in recent years in Iran. Yet no efficient and effective management methods have been found to control the disease. The present study aimed to provide a suitable method for charcoal disease management through silviculture operations, systemic pesticides and biological compounds. The results showed that, simultaneous implementation of silvicultural practices (scarification+sanitation), use of systemic fungicides and Trichoderma compounds, reduce the number and depth of cankers, increase callus thickness, and ultimately improve health of the diseased trees. But disease severity and fungi activity were increased when scarification operation implements alone. The greatest effectiveness of the treatments and health condition improvement of the diseased trees was observed 12 months after applying the treatments. Then, preventive and therapeutic effectiveness of the treatments reduced over time. Sanitation and scarification practices can increase soil permeability and also destroy the larvae, pupa or adult insects and oak borer beetles that play an important role in disease outbreaks. Therefore, simultaneous implementation of sanitation and scarification practices with application of biological and systemic compounds can reduce primary source of pathogen inoculum and help trees to recover their health.

HEALING OF LONG BONE FRACTURES IN PATIENTS WITH CONCOMITANT HEAD OR SPINAL CORD INJURIES

The aim of this prospective controlled study is to compare healing rate and amount of union callus formed in patients with long bone fractures and concomitant head or spinal cord injuries to patients with long bone fractures only. The healing markers of fractures were compared in three groups of patients: (A) patients with head injuries and long bone fractures, (B) patients with acute traumatic spinal cord injuries and long bone fractures, and (C) patients with long bone fractures only. The mean (range) time to union of long bone fractures in groups (A), (B), and (C) patients was 6.9 (3–20), 6.2 (3–7.7), and 22.4 (13–41) weeks. The mean (range) healing rate of long bone fractures in groups (A), (B), and (C) patients was 4.5(0.2–10.6), 4.7 (2.6–7.5), and 0.38(0.11–1)[Formula: see text] mm/week. The mean (range) thickness of callus formed at fracture sites in groups (A), (B), and (C) patients was 26(4–48), 29(10–48), and 1(2–20)[Formula: see text]mm. There were no cases of delayed or nonunion in groups (A) and (B) patients while 5 of 69 fractures (7.3%) had delayed union in group (C) and 9/69 (13%) fractures had nonunion. These results suggest acceleration of long bone fractures in patients with head or spinal cord injuries.

Individual and combined effects of noise-like whole-body vibration and parathyroid hormone treatment on bone defect repair in ovariectomized mice.

The effectiveness of intermittent administration of parathyroid hormone and exposure to whole-body vibration on osteoporotic fracture healing has been previously investigated, but data on their concurrent use are lacking. Thus, we evaluated the effects of intermittent administration of parathyroid hormone, whole-body vibration, and their combination on bone repair in osteoporotic mice. Noise-like whole-body vibration with a broad frequency range was used instead of conventional sine-wave whole-body vibration at a specific frequency. Mice were ovariectomized at 9 weeks of age and subjected to drill-hole surgery in the right tibial diaphysis at 11 weeks. The animals were divided into four groups (n = 12 each): a control group, and groups treated with intermittent administration of parathyroid hormone, noise-like whole-body vibration, and both. From postoperative day 2, the groups treated with intermittent administration of parathyroid hormone and groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration were subcutaneously administered parathyroid hormone at a dose of 30 µg/kg/day. The groups treated with noise-like whole-body vibration and groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration were exposed to noise-like whole-body vibration at a root mean squared acceleration of 0.3g and frequency components of 45-100 Hz for 20 min/day. Following 18 days of interventions, the right tibiae were harvested, and the regenerated bone was analyzed by micro-computed tomography and nanoindentation testing. Compared with the control group, callus volume fraction was 40% higher in groups treated with intermittent administration of parathyroid hormone and 73% higher in groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration, and callus thickness was 35% wider in groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration. Indentation modulus was 46% higher in groups treated with noise-like whole-body vibration and 43% higher in groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration, and hardness was 31% higher in groups treated with both intermittent administration of parathyroid hormone and noise-like whole-body vibration compared with the control group. There was no interaction between the two treatments for both structure and mechanical indexes. The main effects of intermittent administration of parathyroid hormone and noise-like whole-body vibration on bone repair included increased bone formation and enhanced mechanical function of regenerated bone, respectively. The combined treatment resulted in further regeneration of bone with high indentation modulus and hardness, suggesting the therapeutic potential of the combined use of noise-like whole-body vibration and intermittent administration of parathyroid hormone for enhancing osteoporotic bone healing.

Healing patterns of clavicular birth injuries as a guide to fracture dating in cases of possible infant abuse.

Dating fractures is critical in cases of suspected infant abuse. There are little scientific data to guide radiologists, and dating is generally based on personal experience and conventional wisdom. Since birth-related clavicular fractures are not immobilized and their age is known, we propose that an assessment of these injuries may serve as a guide for dating inflicted fractures in young infants, acknowledging that patterns observed in the clavicle may not be entirely generalizable to other bones injured in the setting of abuse. One hundred thirty-one radiographs of presumed birth-related clavicular fractures in infants between 0 and 3 months of age were reviewed by two pediatric radiologists with 30 and 15 years' experience. Readers were asked to evaluate images based on several parameters of fracture healing, with a focus on subperiosteal new bone formation (SPNBF) and callus formation. SPNBF and callus were each evaluated with regard to presence, thickness and character. Responses were correlated with known fracture ages. SPNBF was rarely seen in fractures less than 7 days old and was most often present by 10 days. Callus formation was rarely seen in fractures less than 9 days old and was most often present by 15 days. SPNBF thickness increased with fracture age and the character of SPNBF evolved from single-layered to solid/multilayered. Callus thickness decreased with fracture age and callus matrix evolved from soft to intermediate to hard in character. There is an evolution in clavicular fracture healing in young infants that follows a predictable pattern. These findings afford the prospect that predictable patterns of infant clavicular fracture healing can provide an evidence base that may be applicable in cases of suspected infant abuse.

Role of allogenic mesenchymal stem cells in the reconstruction of bone defect in rabbits

Background: Despite the advancement of bone reconstruction in the past decade, large bone defect remains a challenge for orthopedic surgery. As mesenchymal stem cells (MSCs) emerges as one of the possible treatment of these defects, we evaluate the effect of its transplantation, particularly in combination with hydroxyapatite-calcium sulphate pellets. Methods: Twenty eight rabbits were randomly assigned into four different treatment groups. Each group received a different type of grafts (Autograft, hydroxyapatite-calcium sulphate [HA-CaSO 4 ], HA-CaSO 4 combined with marrow aspirate, or HA-CaSO 4 combined with 2x10 6 MSCs). One centimeter long bone defects were created then immediately fixated with mini plate-screw and two cerclage wires. It was followed by the graft transplantation. Callus thickness was measured from the x-rays taken at 4, 8, 12 week after transplantation by two authors working independently. At the end of the study, histological staining along with osteocyte index were obtained by sacrificing the rabbits. These data were analyzed by one-way ANOVA test. Results: At the fourth week, callus thickness showed significant difference (p = 0.018). Although statistically insignificant, callus in MSCs group at the eighth week seemed to be thicker than any other groups of intervention (p = 0.546). The MSCs group also tend to have a higher osteocyte index at the follow-up weeks. Conclusion: MSC transplantation on bone defect results in faster callus formation and tends to generate a thicker callus. Keywords: bone defect, callus thickness, hydroxyapatite-calcium sulphate, mesenchymal stem cells, osteocyte index

Long-term effects of alendronate on fracture healing and bone remodeling of femoral shaft in ovariectomized rats

To investigate the long-term effects of alendronate (Aln), a widely used oral bisphosphonate, on fracture healing and bone remodeling in ovariectomized rats. Adult female SD rats underwent ovariectomy, and then bilateral femoral osteotomy at 12 weeks post-ovariectomy. From d 2 post-ovariectomy, the animals were divided into 3 groups, and treated with Aln (3 mg·kg(-1)·d(-1), po) for 28 weeks (Aln/Aln), Aln for 12 weeks and saline for 16 weeks (Aln/Saline) or saline for 28 weeks (Saline/Saline). At 6 and 16 weeks post-fracture, the fracture calluses were examined with X-ray radiography, and biomechanical testing and histological analysis were performed. The calluses were labeled with tetracycline and calcein to evaluate the mineral apposition rate (MAR). The fracture line was less distinct in the 2 Aln-treated groups at 6 weeks post-fracture, and disappeared in all the 3 groups at 16 weeks post-fracture. The size of the callus and radiographic density of the femora in the Aln/Aln group were the highest among the 3 groups at 6 and 16 weeks post-fracture. Similar results were observed in the ultimate load at failure and energy absorption. However, the treatment with Aln delayed endochondral ossification of the callus, and significantly increased the total sagittal-sectional area, percentage callus area and callus thickness, and decreased the MAR at 6 and 16 weeks post-fracture. In the ovariectomized rat model, Aln is beneficial for the mechanical properties of the callus, but delays callus remodeling by suppressing the remodeling of woven bone into lamellar bone.

Laser Evoked Bio-stimulation for Bone Fracture Healing (Case Report Study)

Summary: BACKGROUND: The stimulating effect of low level laser phototherapy on bone healing has been shown in a number of in vitro and animal studies. However, the effect of LLLT on the bone healing in human has not been previously wide demonstrated. The article reports an accidentally injury pattern and reported as fractures of the mid third of the left tibia. OBJECTIVE: The purpose of this case study was to demonstrate the biological effects of low-level laser therapy (LLLT) on tibial fractures treated surgically using radiographic, examinations. CASE REPORT: The case hospitalized for conventional surgery and followed by applying Low Level Laser Therapy LLLT to enhance and accelerate the bone fracture healing of the left tibia using the effect of laser bio-stimulation. Radiological x-ray imaging evaluation follow up for our case showed a significant bone healing rate as result of exposure of Diode Laser 650 nm with energy density of 5 J/cm 2 three times/week for one month. Radiographic findings revealed no significant fracture callus thickness difference before using LLLT however, the fractures showed significant callus formation after using LLLT. CONCLUSION: The study suggests that LLLT accelerates the process of fracture repair or cause increases in callus volume

The effects of an injury to the brain on bone healing and callus formation in young adults with fractures of the femoral shaft

In patients with traumatic brain injury and fractures of long bones, it is often clinically observed that the rate of bone healing and extent of callus formation are increased. However, the evidence has been unconvincing and an association between such an injury and enhanced fracture healing remains unclear. We performed a retrospective cohort study of 74 young adult patients with a mean age of 24.2 years (16 to 40) who sustained a femoral shaft fracture (AO/OTA type 32A or 32B) with or without a brain injury. All the fractures were treated with closed intramedullary nailing. The main outcome measures included the time required for bridging callus formation (BCF) and the mean callus thickness (MCT) at the final follow-up. Comparative analyses were made between the 20 patients with a brain injury and the 54 without brain injury. Subgroup comparisons were performed among the patients with a brain injury in terms of the severity of head injury, the types of intracranial haemorrhage and gender. Patients with a brain injury had an earlier appearance of BCF (p < 0.001) and a greater final MCT value (p < 0.001) than those without. There were no significant differences with respect to the time required for BCF and final MCT values in terms of the severity of head injury (p = 0.521 and p = 0.153, respectively), the types of intracranial haemorrhage (p = 0.308 and p = 0.189, respectively) and gender (p = 0.383 and p = 0.662, respectively). These results confirm that an injury to the brain may be associated with accelerated fracture healing and enhanced callus formation. However, the severity of the injury to the brain, the type of intracranial haemorrhage and gender were not statistically significant factors in predicting the rate of bone healing and extent of final callus formation.

Towards an assessment of bone fracture healing using pulsed mode ultrasound

Healing rate of fractured bone differs from one patient to another which may lead to incorrect consequent medical procedures. Thus, quantitative assessment of bone healing after fracture becomes important. In this paper, we present a mathematical model which describes the interaction of a pulsed mode ultrasound waves with a multilayered biological structure. The model is applied to estimate the bone callus thickness and degree of hardness. Different frequencies are utilized to obtain highest measurement sensitivity and accuracy of callus thickness and degree of hardness. It is found that a transducer operating at 1 MHz has the highest sensitivity to the different phases of callus hardening. On the other hand, a 3 MHz transducer yields the highest sensitivity to the thickness of the callus layer. Thus, using both frequencies might prove to be useful for full quantitative assessment of the bone healing process.

Combination of interfragmentary screws and locking plates in distal meta-diaphyseal fractures of the tibia: A retrospective, single-centre pilot study

If distal tibia fractures cannot be treated with intramedullary nails, locking compression plates, such as the LCP Medial Distal Tibia Plate of Synthes, are used. Bridge plating with interfragmentary movement is the strategy for such osteosynthesis. Interfragmentary movement is difficult to predict. Too much movement leads to formation of more, but less stable callus; longer time until complete fracture healing has been reported. Interfragmentary movement can be controlled by the stability and flexibility of the osteosynthesis construct. We used interfragmentary screws to limit interfragmentary movement in certain cases. We noticed a tendency of faster fracture healing in patients with interfragment lag screw compared with those with sole bridge plating. We therefore retrospectively assessed our patients for time until clinical fracture healing (i.e., pain-free weight bearing and visible callus in both layers on conventional plain film radiographs) and callus formation. Methods Data (from patient chart and from regular visits) of 52 patients with fracture of the distal tibia were reviewed, of which 11 were lost to follow-up. After surgery, weight bearing was limited to 20 kg for 6 weeks and then increased in weekly intervals to the pain threshold. X-rays were taken after 3 days, 6, 12 and 24 weeks and when achieving full weight bearing. Time from surgery until ability to full weight bearing was measured and compared. Callus index was measured as quotient of callus thickness and diameter of corticalis both in a.p. and sagittal direction. Statistical evaluation was done with the Mann–Whitney U-test. Results A total of 41 patients could be analysed; of them, 30 patients had extra-articular fractures. Four patients had 43-B and seven patients had 43-C fractures. As many as 13/30 extra-articular fractures were treated with interfragmentary screws: In this group ( n = 11, without considering one patient with plate failure and one with pseudarthrosis) time to full weight bearing was 11.38 weeks versus 14.9 weeks without screw ( n = 14; without two pseudarthrosis and one deep infection) ( p = 0.044). Callus index at full weight bearing was significantly lesser in patients with screw compared with those without. Conclusion Though interfragmentary screws seem to block necessary interfragmentary movement, we see callus formation as a sign of secondary fracture healing. The osteosynthesis construct with interfragmentary screw seems to be more stable and less flexible than sole bridge plating, leading to faster fracture healing. Interfragmentary screws might help to control and limit interfragmentary movement in certain cases.

Shell phenotypic variation in the south-western Atlantic gastropod Olivancillaria carcellesi (Mollusca: Olividae)

Phenotypic variation on shell size and shape of Olivancillaria carcellesi from four representative localities is confirmed using geometric morphometric techniques. This species lives along the entire range of the genus in subtidal soft bottoms from Rio de Janeiro (Brazil) to Punta Pardelas (Chubut, Argentina). Thickness of columellar callus, length and width are the main shell differences from specimens collected at several intermediate localities: Cassino (Brazil), La Paloma (Uruguay) and Mar del Plata (Argentina). All forms showed significant differences in shell size except O. carcellesi from La Paloma compared with those from Mar del Plata. The group with larger specimens was from Cassino. Olivancillaria carcellesi from Punta Pardelas, the southernmost population, was the smaller sized group and showed allometry between size and shape and this is responsible for their relatively higher spires. The possible ecological implications of the observed pattern are discussed. It is confirmed that O. carcellesi although variable, is a clearly defined species.

Neuropeptide Y innervation during fracture healing and remodeling

Background and purpose Autonomic neuropeptide Y (NPY) is involved in local bone remodeling via the central nervous system. However, the role of peripheral neuronal NPY in fracture healing is not known. We investigated the relationship between bone healing and side-specific occurrence of NPY in angular and straight fractures.Methods Tibial fractures in Sprague-Dawley rats were fixed with intramedullary pins in straight alignment and anterior angulation. The samples were analyzed by radiography, histology, and immunohistochemistry (IHC) between 3 and 56 days postfracture.Results In the angular fractures, radiography and histology showed a 3.5-fold increase in callus thickness on the concave side compared to the convex side at day 21, whereas a 0.2-fold reduction in callus thickness was seen on the convex side between days 21 and 56. IHC showed regenerating NPY fibers in the callus and woven bone in both fractures at day 7. In angular fractures, a 5-fold increase in NPY fibers was observed on the concave side compared to the convex side at 7 days, whereas a 6-fold increase in NPY fibers was seen on the convex side between 21 and 56 days; only a 0.1-fold increase in NPY fibers was seen on the concave side during the same time period. In straight fractures, similar bony and neuronal changes were observed on both sides.Interpretation The increase in NPY innervation on the convex side appears to correlate with the loss of callus thickness on the same side in angular fractures. Our results highlight the probable function of the peripheral NPY system in local bone remodeling.

Effect of Lower-Level Laser Therapy on Rabbit Tibial Fracture

The purpose of the study was to demonstrate the biological effects of low-level laser therapy (LLLT) on tibial fractures using radiographic, histological, and bone density examinations. Fourteen New Zealand white rabbits with surgically induced mid-tibial osteotomies were included in the study. Seven were assigned to a group receiving LLLT (LLLT-A) and the remaining seven served as a sham-treated control group (LLLT-C). A low-energy laser apparatus with a wavelength of 830 nm, and a sham laser (a similar design without laser diodes) were used for the study. Continuous outflow irradiation with a total energy density of 40 J/cm(2) and a power level of 200 mW/cm(2) was directly delivered to the skin for 50 seconds at four points along the tibial fracture site. Treatment commenced immediately postsurgery and continued once daily for 4 weeks. Radiographic findings revealed no statistically significant fracture callus thickness difference between the LLLT-A and LLLT-C groups (p > 0.05). However, the fractures in the LLLT-A group showed less callus thickness than those in LLLT-C group 3 weeks after treatment. The average tibial volume was 14.5 mL in the LLLT-A group, and 11.25 mL in the LLLT-C group. The average contralateral normal tibial volume was 7.1 mL. Microscopic changes at 4 weeks revealed an average grade of 5.5 and 5.0 for the LLLT-A group and the LLLT-C group, respectively. The bone mineral density (BMD) as ascertained using a grey scale (graded from 0 to 256) showed darker coloration in the LLLT-A group (138) than in the LLLT-C group (125). The study suggests that LLLT may accelerate the process of fracture repair or cause increases in callus volume and BMD, especially in the early stages of absorbing the hematoma and bone remodeling. Further study is necessary to quantify these findings.

Site‐specific CGRP innervation coincides with bone formation during fracture healing and modeling: A study in rat angulated tibia

Sensory neuropeptide involved in local bone turnover is known, but poorly understood. In the present study, we analyze the occurrence of neuronal CGRP during healing and modeling of straight and angular tibial fractures in 74 rats. Bone healing and modeling was assessed by radiography and reinnervation by semi-quantitative immunohistochemistry method at fracture site between 1-12 weeks postfracture. The regenerating nerve fibers containing CGRP were observed in fracture callus as well as in close proximity to chondrocytes, with woven bone in both fractures already at week 1. Notably, it located predominantly on the concave side of angulated fracture in the manner of sprouting into bone from weeks 3 to 5 postfracture. In both fractures, fracture calluses peaked radiographically at week 3 postfracture. In angulated fracture, a reduction of 11% in callus thickness on convex side and an increase of 365% on concave side were noted from weeks 3 to 12. A 27-fold increase in total neuronal CGRP in straight fracture and 38-fold increases in angular fracture compared to intact bone was observed at week 3. In both types of fracture, neuronal CGRP was greater on the concave side than the convex; this difference was more pronounced in the angulated fracture. CGRP immunoreactivity clearly coincides with amount of new bone formation especially on the concave side of angulated fracture. The combined results suggest that fracture evokes an intense, localized in-growth of new nerve fibers containing CGRP, which may prove to be a prerequisite of fracture healing and modeling.