PURPOSE: The present study was performed to determine the optimum conditions(RPM, load, sharpness of drill) for drilling human cortical bone with standard drill, and to evaluate the histological changes occuring in bone after drilling. MATERIALS AND METHODS: in experiment I, we measured temperature elevations and the durations of temperature elevation in cadaveric femoral cortices at specific distances from the drill hole wall while drilling. The effects of drilling force, speed and new versus worn drill on the termperature were determined. In experiment II, we also measured temperature elevations in the same manner in porcine femoral cortices and evaluated the histological changes occuring in bone after drilling. RESULTS: In experiment I, the most significant temperature elevation(68.4degrees C ) was found when worn drill was used. The lower drilling force and faster speed resulted in 55.1degrees C and 45.8degrees C temperature elevation, respectively. However, drill diameter was not a significant factor for temperature elevation. In experiment II, greater heat production was measured with worn drill, at lower drilling forces, at faster drill speed. The acute histologic reactions in bone were hyperemia, degeneration of osteocytes, change in bone stainability, tears, and fragmentation of the bone edges around the drill holes. The observed histological changes were proportional to the amount of trauma produced, that is, the greater the degree of thermal irritation, the greater the degree of histologic activity. CONCLUSION: In cortical drilling, greater heat production was measured with worn drill, at lower drilling forces, at faster drill speed and the greater the degree of thermal irritation, the greater the degree of histologic activity. A further study of the reaction of bone to drilling at longer intervals of time at different conditions may possibly show whether aseptic thermal necrosis could be prevented.
Cadaver ; Hot Temperature* ; Humans ; Hyperemia ; Necrosis* ; Osteocytes ; Thermogenesis*

We intended to evaluate the Young's modulus of trabecular bone and apparent density from Computed Tomography(CT) and Spherical Indentation test and to quantify relation ship between them. The distal femurs(31 age, male, left and right) were prepared for exprimentatin and were embedded with repect to anatomical orientation. Then the specimens were scnned at 1 mm intervals on GE9800 CT scanner and the Hounsfield Units(HU, or CT number) were extracted from each CT image. After scanning, the bones were sectioned with diamond saw, producing 8 mm cubes of trabecular bone(72 eachs) from the metaphyseal region of both distal femur. The cubes were mechanically tested in inferior-superior(IS), anteriorposterior(AP), and medial-lateral(ML) direction with custom-made device, Spherical Indentatin Tester. After testing, the real apparent density of specimens were measured. The results of this study showed that the IS modulus was singificantly greater than both the AP and ML modulus and the AP modulus was also greater than ML modulus significantly(p<0.01). A linear relation ship between HU and real apparent density was found to be significant(R2=0.68) and significant power relationship between the apparent density and the tangent moduli(either by CT or physical measures) was also found.
Diamond ; Elastic Modulus* ; Femur ; Humans* ; Male ; Ships

Allografts or autografts of bone-tendon unit have been used for ligament injuries or deficiencies after limb salvage operation for malignant bone tumors around joints. While the remodeling process of the ligament or tendon of the allograftor autograft and the microscopic and biomechanical changes of tendon-bone graft interface have been widely investigated, little is known about the ultrastructural and biochemical changes of the transitionall zone in tendon-bone junction. This study was performed to analyzed the ultrastructural and biochemical changes of the transitional zone after tendon-bone auto-and allo-grafting. A total of twenty four rabbits were divided into two group. In 12 animals(allograft group), two Achilles ten-don-bone unit per each animal were taken and transplanted to another rabbit after preservation below -70degrees C for 2 weeks. In the other 12 animals(autograft group), the Achilles tendon-bone unit was harvested from one side and transplanted to the other side of the rabbit. After operation, their legs were immobilized with short leg cast for 4 weeks, and then mobilized freely. Four animals in each group were sacrificed at four, eight and sixteen-weeks after the transplantation, and their grafted Achilles tendon-bone interfaces were used for analysis of the ultrasturctural and biochemical changes. The following results were obtained. 1. Histologically new cartilage cells were observed at postoperative 16 weeks with local presence of faint tidemark in the autograft group but not in the allograft group. Complete remodeling of the transitional zone had not observed histologically in both groups. 2. Ultrasturctural analysis revealed no definite differences between both groups. However, the slightly rapid appearance of parallelism and cross-striation of microfibrils in the autograft group and time-related restoration of fibers and fibroblasts were observed. 3. From biochemical analysis, type I collagen concentratin was increased, and an early rapid increase of type III collagen and glycosaminoglycan were also observed. In conclusion, these data suggested that type III collagen and glycosaminoglycan are important in stabilization of grafted tendon-bone unit, especially in the transitional zone. The histological and biochemical changes in allograft group were relatively similar to that of autograft group although the allograft group showed the delayed pattern of remodeling. Therefore, the tendon- allograft could be used as a good substitute for the autograft for tendon or ligament reconstruction when no suitable autograft is available.
Allografts ; Animals ; Autografts ; Cartilage ; Collagen Type I ; Collagen Type III ; Fibroblasts ; Joints ; Leg ; Ligaments ; Limb Salvage ; Microfibrils ; Rabbits* ; Tendons ; Transplants*

Platelet-derived growth factor(PDGF) is known to accelerate soft tissue fracture and periodontal bone healing, but little information is available for characterizing the healing of articualr cartilage. This study was designed to demonstrate the regeneration potential of pasteurized autogeneous osteochondral graft when PDFG was applied locally in vivo. Eighteen rabbits in two groups were used in the experiment. The free osteochondral fragment(1x1x1 cm) were taken from distal femur. The fragment were pasteurized in 65degrees C for 5 minutes. In experimental group(group II), the fragment were soaked in 0.25 mg/ml of recombinant human PDGF mixed 5 ml normal saline and reimplanted to the resected site, and followed with local administration of 0.25 mg/ml PDGF to knee joint. In control group(group I), the pasteurized fragment were reimplanted in the resected site without any treatments. The histologic characteristics of the transplanted autografts for three rabbits in each group were observed at 3, 5 and 7 weeks postoperatively. The results were as follows; Group II revealed the more favorable regeneration of articular cartilage, less arthritic changes and more mature arrangement of chondrocytes than group I. Even thought the cartilage is avascular and the regeneration capacity of pasteurized cartilage is severely limited, the regeneration of grafted articular cartilage is thought to be accellerated by increased newly formed blood vessels and soft tissues due to the diffusion of PDGF on grafted cartilage, and probably also by differentiation of mesenchymal cells in the initial stage of experiment. The results of this study suggest that local administration of PDGF could be used for the treatment of posttraumatic or degenerative arthritis and various cartilage damages.
Autografts ; Blood Vessels ; Cartilage ; Cartilage, Articular ; Chondrocytes ; Diffusion ; Femur ; Humans ; Knee Joint ; Osteoarthritis ; Platelet-Derived Growth Factor* ; Rabbits* ; Regeneration* ; Transplants*

PURPOSE: This study was aimed to determine the relationship between osteopontin(OPN) and osteoclast, especially focused on whether ostecolast could produce osteopontin or not. MATERIALS AND METHODS: Osteoclasts were isolated from the giant cell tumor of proximal tibia and seeded on the 13 mm round cover slip resided in 24 multi-well plates for culture. After 2 days, osteclasts on the cover slip were fixed with cold acetone for 3 minutes and immunocytochemistry was done with rabbit osteopontin antibody. For in situ RT-PCR, osteoclasts on the cover-slips were fixed with 4% paraformaldehyde for 4 hours and were treated to pepsin. PR-PCR was done and the PCR producst were stained with anti-digoxigenin-AP. RESULTS: Osteopontins were found on the surface of the osteoclast by immunocytochemistry, and intense osteopontin mRNAs were found by in situ RT-PCR. CONCLUSION: We have identified that osteoclast could synthesize the osteopontin, and confirmed that in situ RT-PCR was a very useful method in expressing small amount of mRNA in case of mixed cell culture. Further study was needed to identify the action of the osteopontin produced by the osteoclast.
Acetone ; Cell Culture Techniques ; Giant Cell Tumors ; Immunohistochemistry ; Osteoclasts* ; Osteopontin* ; Pepsin A ; Polymerase Chain Reaction ; RNA, Messenger ; Tibia

We built the hypothesis that the hypertrophic callus formation is mediated by beta-endorphin that stimulates secretion of GH and increase circulation growth factor activity in head injury patient. We classified 4 groups such as 5 normal person(control), group I;5 patients with only fracture, group II;5 patients with fracture and head injury, group III; 5 patients with only head injury, group IV. We obtained the samples of serum from each group at 0, 2, 4, 6, 8 weeks after trauma and assessed the serum level of GH, GHRH, somatostatin. The serum level of GH was statisticallyu higher in group III, IV than group I, II. There was not significant difference in serum level of GHRH. The serum level of somatostatin was higher in group II, III, IV than group I, but there was no statistical significance in each group. GH has a important role in hypertrophic callus formation in severe head injury patients, but there was no evidence that the mechanism is mediated by beta-EndorphinGHRH & somatostatin-GH-GF-1, beta-FGF axis. There may be a another mechanism in increasing GH that was stimulated by beta-endorphin in thalamus and lateral ventricle, and it should be necessary for further evaluation of it.
Axis, Cervical Vertebra ; beta-Endorphin ; Bony Callus ; Craniocerebral Trauma* ; Head* ; Humans ; Lateral Ventricles ; Somatostatin ; Thalamus

This study was conducted to invetigate the effect of high-dose steroid administration on adipogenesis and secretion of PAI-1 in rat. Sixty healthy Wistar rats were divided into three groups. Group A consisted of 20 control animals received 5 ml/kg isotonic saline for 1 weeks. Group B consisted of 20 animals received 10 ml/kg of methylprednisolone intraperitoeally for 1 week. Group C comprized 20 animals received 10 ml/kg of methylprednisolone intraperitoneally for 1 week. After the completionof treatment, blood sampling was performed for measurenement of PAI-1 and the animale were sacrificed for histopathologic examination and immunohistochemical study. The PAI-1 protein expressin of femoral heads were evaluated with Western-blotting. Blood level of PAI-1 increased significantly in high-dose steroid treated group(Group B and C) compared to control group. In histopathologic examination, significant fat morrow conversion, fat cell hypertrophy and fat cyst formation were observed in high-dose steroid treated group. Immunohistochemically, PAi-1 expression was sprominent in the fat cells. Protein expression of PAI-1 of femoral heads increased significantly in highdose steroid treated group compared to control group. In lights of above results, it is postulated that increased secretion of PAI-1 from fat cells could play a major role in the pathogenesis of osteonecrosis of the femoral head in rats treated with high-dose steroid.
Adipocytes ; Adipogenesis* ; Animals ; Head ; Hypertrophy ; Methylprednisolone ; Osteonecrosis ; Plasminogen Activator Inhibitor 1* ; Rats* ; Rats, Wistar

The use of interlocking intramedullary nail is accepted one of treatment choices in the comminuted fractures of humeral shaft. The insertion of distal interlocking screws remains technically problematic. The use of intrageon's hands during the procedure. In order to reduce technical difficulty and radiation exposure, it is necessary to compare the rigidity of intramedullary nail according to the number of distal interlocking screws. The purpose of study is to compare the stability of interlocking intramedullary nail according to the number of distal screws by means of torsional compliance measurements in the simulated humeral shaft fractures. Simulated fractures were made in 20 humora from 10 cadavera at the mid-junction of humeral shaft. All humora were fixated with titaium humeral nail system. Interlocking screws were placed at proximal and distal screw holes by standard procedure. Group I consisted of 10 humora fixated with one distal interlocking screw and group II consisted of 10 humora fixated with two distal intterlocking screws. Torsional compliance was measured with single-end of 10 humora fixated with two distal interlocking screws. Torsional compliance was measured with single-end double arm torquing machine. The torsional compliance analog was 0.0294+/-0.0033 mm/N mm for one screw and 0.0241+/-0.0045 mm/N mm for two distal screws. The torsional compliance analog between two groups was found to be statistically insignificant(p=0.23). In conclusion, One distal interlocking screw was not inferior to two interlocking screws in terms of biomechanical characteristics, especially torsional compliance analog.
Arm ; Compliance ; Fracture Fixation, Intramedullary* ; Fractures, Comminuted ; Hand

Localized pigmented villonodular synovitis (LPVNS) is a rare lesion that can affect any joint, although it is most frequently found in the knee. When LPVNS affects the knee, it is usually a single mass of pedunculated appearance. We present a LPVNS occurred from the junction of the anterior horn of the lateral meniscus and the joint capsule in the knee. It detached and then moved at an unusual location, which caused pain, limitation of knee flexion and locking.
Animals ; Horns ; Joint Capsule ; Joints ; Knee* ; Menisci, Tibial ; Synovitis, Pigmented Villonodular*

Synovial hemangioma is a rare benign intraarticular tumor. Synovial hemangioma of the knee joint has unspecific symptoms, which are pain, limitation of motion and hemarthrosis, often seen as an internal derangement of the knee. A 24-year-old woman presented with intermittent joint effusion and pain of the left knee joint and physical examination revealed slight atrophy of the quadriceps and tenderness around lateral joint line of knee. The patient was performed arthroscopic surgery due to synovial hemangioma about 17-years ago. Magnetic resonance imaging (MRI) showed the synovial hemangioma from Hoffa fat pad to anterior aspect of lateral meniscus, and thus surgical treatment was planned. Arthroscopic excision was performed and additional lesion was observed in lateral gutter, suprapatellar pouch of the knee. The biopsy confirmed the diagnosis of synovial hemangiomas. After 3 year, the patient was completely asymptomatic and showed no signs of recurrence.
Adipose Tissue ; Arthroscopy ; Atrophy ; Biopsy ; Diagnosis ; Female ; Hemangioma* ; Hemarthrosis ; Humans ; Joints ; Knee Joint ; Knee* ; Magnetic Resonance Imaging ; Menisci, Tibial ; Physical Examination ; Recurrence ; Young Adult