Iranian Journal of Orthopedic Surgery

Abstract Abstract
 
Introduction: Bone fracture is one of the most common bone injuries in the world. It is, therefore, not surprising that bone healing is a critical orthopedic problem. Currently, bone grafts (autografts, allografts and xenografts) have been used as bone replacement strategies. The purpose of this study was to evaluate the efficacy of application of chitosan (CHS) as an osteo-inducer in the process of bone healing.
Materials and Methods: Fifteen male rats, in the same age and weight range, were divided into three groups of 5.  3 mm of metaphysis of the radius bone of each animal was removed. The defect was left empty in the first ,   filled with autograft in the second ,and filled with CHS in the third group. Radiographs of the defects were obtained  on  28^th  and 56^th  day post-operation. The animals were euthanized according to human ethics and the defects  were investigated histologically  on  the 56^th  post-operation day.
Results and Discussion: According to radiographic and histopathologic results, CHS indicated a improved  effect ,and improved bone healing process in comparison with the other two treatment modalities.
Conclusion: It can be concluded that use of chitosan improves the potential for  bone formation and bone healing criteria. These composite materials, however,  deserve more  studies.

Abstract Abstract Introduction: Bone defects resulting from trauma, pathological conditions, or surgical interventions often require advanced regenerative strategies, particularly when critical-sized defects exceed the body’s intrinsic healing capacity. Among various biomaterials, Leukocyte- and Platelet-Rich Fibrin (L-PRF) has gained significant attention for its autologous origin, bioactive properties, and potential application in both autologous and xenogenic forms to enhance bone regeneration. Materials & Methods: Adult male Wistar rats were randomly divided to four experimental groups to evaluate the effects of equine-derived lyophilized L-PRF, with or without autologous bone grafts, on critical-sized radial bone defects. L-PRF was prepared from equine blood, lyophilized, and applied to the defect sites, with bone healing assessed via radiography and histopathology, and statistical differences among groups analyzed using non-parametric methods. Results & Discussion: Radiographic and histopathological analyses demonstrated that the autograft + L-PRF group exhibited the most pronounced bone healing, with significantly higher Lane and Sandhu scores and evidence of progressive cartilage-to-bone formation compared to the L-PRF alone and empty defect groups. The autograft group also showed superior outcomes relative to L-PRF alone, while untreated defects displayed primarily fibrous tissue with no bone formation, highlighting the synergistic effect of combining L-PRF with autologous bone grafts. Conclusion: In this study, xenogenic equine-derived L-PRF enhanced the repair of critical-sized radial bone defects in rats, with its combination with autografts yielding superior osteogenic outcomes compared to L-PRF alone.      

Abstract Abstract
Introduction: This study was performed to evaluate the effect of lyophilized human platelet rich plasma powder (LhPRP) and omentum autograft on the bone healing properties in animal model which can further be utilized for different orthopedic or maxillofacial reconstructive surgeries.
Materials & Methods: Bone defects of 10 mm diameter were created in diaphysis of radius of 20 rabbits and then either left undisturbed (control group) or filled with one of the following materials: a piece of autogenous omentum, LhPRP, or concurrent use of LhPRP and omentum. Bone formation, union and remodeling, were evaluated at the 2nd, 4th, 6th and 8th weeks postoperatively by radiography, using bone healing criteria. On 56th postoperative day, the operated limbs were removed and further histopathological evaluations were carried out.
Results & Discussion: The results showed that LhPRP with or without omentum in bone regeneration in 10mm defects was significantly superior to control group (p<0.05).
Conclusion: LhPRP powder, alone or combined with autogenic omentum, provides increased bone regenerative properties in experimental bone defects in animal model after 56 days.
Keywords: Omentum, Lyophilization, Platelets, Bone regeneration, Rabbits.

Abstract Background: Facilitating the fracture healing process is important to increase the fracture healing speed and to decrease the time period till union. This study aimed to evaluate the effects of blood clot and doxycycline on bone healing process.
Methods: Twenty mature male New Zealand white rabbits were used, in this study. A defect was created in the middle part of the radius. The rabbits were randomly distributed into 4 groups and the gaps were filled with the graft materials: blood clot, doxycycline, combination of blood clot and doxycycline and control group in which the defect was left empty. Radiographs of operated limbs were taken on 14th, 28th, 42nd and 56th postoperative days. Histologic samples were taken on the 56th day post surgery.
Results: On radiographic evaluation significant difference between the groups was not observed (p>0.05). On histopathological evaluation, blood clot and doxycycline groups were superior to control group (P<0.05), also combination of blood clot and doxycycline group was superior to other ones (P<0.05). There was no evidence of graft rejection in any group.
Conclusion: This study demonstrated that the combination of blood clot and doxycycline has a better function in bone healing process than other groups.

Abstract Abstract
Background: Nowadays, bone grafts are used in both veterinary and human orthopaedics to stimulate fracture healing and to accelerate the restoration of bone defects. Autografts are still a high standard for comparing different bone-building stimuli. Autografts not only include healing stimulants but also contains cells that do not stimulate immune responses and do not transmit infectious diseases. However, bone grafting is not without side effects such as pain, infection, fracture, blood loss and increased surgical stages, besides the amount of bone removed is limited.
Tarantula cubensis venom has an anti-inflammatory and re-epithelialization effect in bovine wound healing on the 14th day; it also plays a role in infection prevention since Theranekron can alter the process of inflammation. This study aims to examine the effect of hydroalcoholic extract of tarantula cubensis on the distal radius fracture healing in rabbits
Methods: This study was conducted on 20 male rabbits, in four study groups of five rabbits. A bone se was extracted from the distal radius. The first group was administrated with one microgram per kilogram of Theranekron injection at the site of the bone defection. The second and third (or negative control) groups were administrated with normal saline injection and no substance (no intervention), respectively. Lastly, the fourth group (or autograft group), the extracted bone segment was returned in its place, and the skin and muscles were sutured. Lateral view radiographs images were taken from rabbits on days of 14, 28, 42 and 56 after surgery.
On the eighth week, a bone biopsy was performed to evaluate histopathology. Radiographs and biopsies were statistically examined for fusion rate, ossification activity and remodelling.
Results and Conclusion: Both Theranekron and autograft group had similar behaviour and outperformed the normal saline and negative control group; therefore it is concluded that hydroalcoholic extract of tarantula cubensis was effective in distal radius fracture healing.
 

Abstract Abstract
Background & Aim: Nowadays, bone grafts are used in veterinary and human orthopedic to stimulate fracture healing, accelerate joint connection, and healing of bone defects. In this study, we carried out the radiological and histopathological evaluation of the effects of nano-hydroxyapatite concurrent with bone marrow treatment on rabbit fracture repair.
Materials and Methods: This experimental study was performed in the spring and summer of 2019 on 20 male New Zealand white rabbits (12-month-old, weight=2 kg). The samples were randomly divided into four groups, and bone segments were removed from the radius. In the first group (n=5) (control), the bone defect remained empty and no substance was injected. Meanwhile, the defects in the second, third, and fourth groups (sample size of five in each group) were filled with nano-hydroxyapatite, bone marrow, and combination of nano-hydroxyapatite and bone marrow. Radiographs of the radius in each rabbit were taken at 2nd, 4th, 6th, and 8th post-operative weeks, and bone biopsy was performed in the eighth week for histopathological assessment. In addition, the radiographs and samples were evaluated in terms of union, ossification activity, and re-forming.
Results: In this study, there was a significant difference among the groups in the second, fourth, sixth, and eight weeks regarding radiographical assessments (P<0.05). However, the difference was more evident in the sixth week, when a significant difference was found between the nano-hydroxyapatite group and a combination of bone marrow and nano-hydroxyapatite group (P=0.02). In this regard, the latter had a better performance, compared to the former. In histopathological evaluation, the group of a combination of nano-hydroxyapatite and bone marrow showed higher ossification activities, compared to the control group.
Conclusion: According to the results of the study, the group of a combination of nano-hydroxyapatite and bone marrow had a better function in terms of bone healing, compared to the other two groups. Therefore, it is suggested that the method be applied to larger animal samples to confirm its clinical implications.

Abstract Background: Bone grafts have been used to stimulate the fracture healing in orthopaedic surgery. Allograft and xenograft are more used because of auto graft use problems. Royal jelly is the principal food source of the queen honey bee. Royal jelly has pharmacological activities such as anti-bacterial, antioxidant, antitumor and anti-inflammatory effects. This research was designed to evaluate the effects of royal jelly on bone healing and restoration in the rabbit model.
Materials and Methods: In this study, we used 10 New Zealand white rabbits with an approximate weight of 2 kg. They were divided into two groups (N=5) midradius bone defect created and filled with royal jelly and in the second group (N=5) the defected filled with nothing. The radiological evaluation performed on days 14th, 28th and 42nd after the operation. Histopathological evaluation was done on 42 days after the operation.
Results: Radiological result has not shown the significant difference in days 14th and 42nd (p>0.05) and only on day 28, there was a meaningful division (p<0.05). There was no significant difference between the two groups in histopathological evaluation.
Conclusion: This study indicates using of royal jelly could accelerate bone healing process in rabbit and has the potential for  use in medicine.
 

Abstract Background: Acceleration of bone healing is one of the most challenging issues in orthopedic science. This study aimed to evaluate bone healing process with the application of fish bone powder and human lyophilized platelet (prepared with a novel protocol) in the rabbit animal model.
Materials and Methods:  This study was carried out on 20 male New Zealand white rabbits (12 month old), divided into four equal groups as control, fish bone powder, lyophilized platelet and a combination of fish bone powder and lyophilized platelet. After exposing the radius, a bone segment (10 mm) was cut from the bone, and the empty space was left empty in the control group but filled with the mentioned biomaterials in other groups. Radiographs of each rabbit were taken on the 14th, 28th, 42nd, and 56th post-operative days to evaluate bone formation, union and remodeling of the bone defect. All animals were euthanized on the 56th post-operative day for histopathological evaluation.
Results: Radiological evaluation showed a significant difference between the lyophilized platelet group (P=0.02) and the control (P=0.007) and the fish bone powder (P=0.005) on 56th post-operative day, where the lyophilized platelet group was superior, compared to other groups. Moreover, the histopathological evaluation revealed a significant difference between the control group (P=0.01), the fish bone powder (P=0.03) and lyophilized platelet group (P=0.01), where treatment groups were superior, compared to the control group on 56th post-operative day. Nonetheless, there was no evidence of graft rejection in all groups.
Conclusion: According to the results of the study, using lyophilized platelet could accelerate the bone healing process in rabbit and has the potential for use in medicine.
 

Abstract Background: The destruction of articular cartilage is the major cause of articular problems. The articular cartilage has little repair postertial due to lack of perichondrium and direct blood circulation. It is, therefore important to consider this phenomena in surgical treatments. One of the articular cartilage reconstructive surgeries is using Osteo-Chondral graft. The main purpose of this research was to investigate the use of Xenogenic (calf foetal) Osteo-Chondral graft in repairing articular cartilage defect on Rabbit’s model.
Methods: Osteo-Chondral pieces were prepared under aseptic condition from the joints by skin punch device and kept at a temperature of 70ºc below zero. Ten male New Zealand rabbits of one year old were randomly divided into two groups of five, as control and transplantation groups calf's fetal. The skin and joint capsule were opened by surgery and articular cartilage was exposed. After defect creation by drill, in the transplanted group an Osteo-Chondral piece was inserted in the defected area; however, in the control group the defect was created but left empty. Joint capsule and skin were sutured in both groups. During 60 days of study, radiographs were taken from rabbits of each group randomly to evaluation of osteoarthritis signs on days 14, 28 and 42. Finally all rabbits were euthanized for histopathological sampling and evaluated on day 60.
Results: The result of the clinical evaluations did not show any sing of inflammation nor limping. In radiological evaluation there was no evidence of arthritis complications but showed defect filling signs in experimental group. In the histopathologic evaluations, the defect of transplanted group was filled with fibro-cartilage tissues and without any signs of graft rejection. In two samples of five specimens of transplanted group Fibrous tissue was the dominant tissue and in other two as the dominant tissue. Only in one sample of this group the integrity of the cartilage tissue was completely formed. But in the control group, the lesions were observed without any restorative tissue and only filled by red blood cells.
Conclusion: The study suggests that Xenogenic Foetal Osteo-Chondral tissue is an effective tissue for repairing articular cartilage defects.
 

Abstract Background: Physical activity reduces the risk of bone fractures by decelerating the bone loss and enhancing muscle strength. Such activities promote the bone strength and bone density through bone stimulation. The present study aimed to compare the effect of endurance training with varying intensities on the selected biomechanical properties of femurs in old male Wistar rats.
Methods: 24 male Wistar rats (23 months old) with an average weight of 441.75 grams were randomly divided into 2 experimental and one control grpups: Moderate intensity continuous training (MICT, n = 8), high intensity Interval training (HIIT, n = 8), and control group (CG, n = 8). Moderate and high intensity endurance training sessions were held five days a week with 60-70% and   80-110% of the maximum speed) and high (maximum speed) for eight weeks, respectively. In the MICT and HIET groups, the duration and distance (volume of training) were the same and only the intensity of training differed. Forty-eight hours after the last training session, the rats underwent surgery and their femur removed. Three–point bending flexural test was used to determine the effects of training on modulation, maximum endurance, fracture energy, and femur strength in the rats. The statistical analysis was performed using one-way ANOVA test at P <0.05.
Results: The study results indicated that eight weeks of endurance training with varying intensities had no significant effect on modulation (p < /em>=0.198), bone strength (p < /em>=0.24), fracture energy (p < /em>=0.204), deformation-to-maximum strength (p < /em>=0.89), and femur strength (p < /em>=0.31), and that no significant difference was observed among the three groups.
Conclusion: The biomechanical changes of the bone by such exercises require longer periods of training, which could be examined in future studies.
 

Abstract Background: Nowadays, bone grafting is used in both human and veterinary orthopedics to stimulate fracture healing, accelerate joint ::::union::::, and to restore bone defects. In such procedures, orthopedic surgeons are searching to favorable substitute for autograft bone. The purpose of this study is evaluation of theranekron and hydroxyapatite effects on bone healing in rabbit model. Methods: First, 20 rabbits were prepared and they were divided into four groups of five. In the group of theranecron, theranecrone was injected to the bone defected site on days 3, 7, and 10 after surgery and one of the group was left empty as control group and in the third group combination of the theranekron and hydroxyapatite was filled in the defected site and in the final group hydroxyapatite was implanted alone. Radiographs from rabbit's hand after surgery were taken on days 14, 28, 42, 56 in lateral view. At the end of the study, histopathological samples were taken from injured area of radius. Results: In radiographical and histopathological evaluations the group of theranekron-hydroxyapatite had the best performance in healing criteria and the control group was the weakest group. Conclusion: theranekron group and theranekron –hydroxyapatite groups were better than two other groups in bone healing criteria by radiological and histopathological evaluation.  

Abstract Background:  Orthopedic surgeons are trying to find best substitutes for bone grafting in human and veterinary medicine. Bone autografts are still as a golden standard in comparison with other bone grafts. Diced ear cartilage from dog and rabbit have been used on bone healing previously, in the present study effects of rabbit and bovine rib cartilages will evaluated in bone healing of rabbit bone defect model.  Method: In this study, 20 adult rabbits weighing approximately 2 kg were used. The rabbits were randomly divided into 4 groups. The bone segment was removed from the mid radial bone. In the first group (N = 5) in the gap segement of bovine rib cartilage was implanted. In the second group (N = 5) in the gap, segement of rabbit rib cartilage was implanted. In the third group (empty control group), (N = 5) the defect was left without implantation. Finally, the fourth group (autograft Group), (N = 5) the defect was filled with a same harvested bone. The skin and muscles were sutured routinely. X-rays were taken on 14th , 28th , 42nd  and 56th postoperative days. Result and conclusion: After 8 weeks bone samples were taken from healed area for for histopathological evaluation. The results of our study indicate allogenic and xenogenic cartilage acted almost like autograft groups and were better than empty group.

Abstract Background: Rupture of tendons is a common injury. The outcome of surgical repair of injured tendon is often unsatisfactory.  At best, the restored tendon is about half of its initial mechanical properties. In this study the effect of zenologous and autologous platelet gel were compared in rabbit model. Methods: 45 rabbits in the age range of 7 months to 1 year old were divided into autologous, zenologous and control groups. Superficial digital flexor tendon was cut transversely and then sutured with Mayer stitch pattern. Then 5cc of either aotologous or zenologous platelet gel was injected to the incision area. The control group had no material injection. On 7th, 14th, and 28th post-operative days, five rabbits of each group were euthanized and tendons were harvested for histopathological and biomechanical evaluations. The results were analyzed statistically. Results: Biomechanical factors were significantly superior in the autologous and zenologous groups than the control group. In histopathological examination the autologous groups showed a significant difference in fibroblast maturation in all the tested weeks. The collagen fiber alignment at 7th postoperative day and collagen accumulation on 7th and 28th postoperative days were superior in autologous compared with zenologous and control groups. Conclusions: Utilization of zenologous platelet gel has a positive effect on tendon healing, but not as good as autologous platelet gel.

Abstract Background: Synthetic hydroxyapatite (HAP), beta-tricalcium phosphate (ß-TCP) and their composite are promising biomaterials specifically in the orthopaedic and dental fields, as their chemical composition is similar to that of bone. Due to the need for safer bone graft applications, these bone graft substitutes are gradually gaining increased acceptability. The purpose of this study was the evaluation of concurrent use of hydroxyapatite with demineralized calf foetal growth plate (DCFGP) effects on bone healing process.Methods: Mid radii bone defect was created in fifteen female New Zealand white rabbits. They were divided into 3 equal groups: In group I the defect filled with DCFGP, in group II was with hydroxyapatite and DCFGP, and in group III with hydroxyapatite alone. Radiographic and histopathologic evaluations were performed blindly and results scored and analyzed statistically.Results: There was a significant difference in bone formation and remodeling at the 56th post-operative day (p < /em>=.03). Group II was superior to group I and III. Histopathologic evaluation revealed significant difference between group II with group I and III.Conclusions: The combination of osteoconductive effect of hydroxyapatiter and osteoinduction of DCFGP will lead to superior bone healing process in comparison with any of those agents when used alone.

Abstract Background: Bioactive bioceramics have been regarded by researchers in recent years. Bioglass and Hydroxyapatite (HA) are the examples of these bioactive bioceramics. Production and characterization of nano bioglass and HA for bone repair applications were the purpose of this study. Methods: Nano bioglass and HA were produced and the particles shape and size were characterized by X-ray flurescence (XRF). The bioactivity of the particles of HA and nano bioglass and combination of the two were tested, by introducing them into the cavities formed in rabbit's Tibia. The incorporation and bone induction of these 3 different paricles in bone were evaluated by radiography and also histopathology of the resected specimens. Results: The characterized tests confirmed that nano bioglass and natural HA were produced with desired composition. The radiographic and histopathologic evaluation illustrated good bioactivity of nano-size bioglass, HA and HA-bioglass composite, leading to restoration of bone defects after 4 to 6 weeks. It was also observed that bioactivity of HA-bioglass composite was superior to bioglass and HA used singularly. Conclusions: The osteoconductivty of HA and osteoinductivity of bioglass combined as a composite lead to excellent bioactivity and good response in the hard bony tissue.