We evaluated the morphological features of the newly formed tissue in an experimental model of tibial callotasis lengthening on 24 lambs, aged from 2 to 3 months at the time of operation. A unilateral external fixator prototype Monotube Triax(®) (Stryker Howmedica Osteonics, New Jersey) was applied to the left tibia. A percutaneous osteotomy was performed in a minimally traumatic manner using a chisel. Lengthening was started 7 days after surgery and was continued to 30 mm. The 24 animals were randomly divided into three groups of 8 animals each: in Group 1, lengthening took place at a rate of 1 mm/day for 30 days; in Group 2, at a rate of 2 mm/day for 15 days; in Group 3, at a rate of 3 mm/day for 10 days. In each group, 4 animals were killed 2 weeks after end of lengthening, and the other 4 animals at 4 weeks after end of lengthening. To assess bony formation in the distraction area, radiographs were taken every 2 weeks from the day of surgery. To study the process of vascularization, we used Spalteholz's technique. After killing, the tibia of each animal was harvested, and sections were stained with hematoxylin and eosin, Masson's trichrome, and Safranin-O. Immunohistochemistry was performed, using specific antibodies to detect collagens I and II, S100 protein, and fibronectin. A combination of intramembranous and endochondral ossification occurred together at the site of distraction. Our study provides a detailed structural characterization of the newly formed tissue in an experimental model of tibial lengthening in sheep and may be useful for further investigations on callotasis.
Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown aetiology that results in progressive destruction of bone and cartilage in affected joints. It has been reported that in mouse bone marrow cell cultures TNF-alpha directly induces osteoclast formation and IL-1alpha stimulates osteoclast activation, and that this osteoclast formation and activation is independent of osteoprotegerin ligand (OPGL) signalling system.1,2
Objectives
TNF-alpha and IL-1alpha considered master cytokines in the process of RA but little is known about the direct effects of these cytokines on development of human osteoclasts. This study aims to determine the role of TNF-alpha and IL-1alpha, on synovial macrophage- and monocyte-osteoclast differentiation in RA.
Methods
Macrophages and monocytes isolated from RA patients were cultured with TNF-alpha and/or IL-1alpha on glass coverslips and dentine slices in the presence of M-CSF. Anti-TNFalpha, anti-IL-1alpha and osteoprotegerin (OPG) was added to this cultures. Cultures were assessed for cytochemical and functional evidence of osteoclast differentiation.
Results
The addition of TNF-alpha and M-CSF was sufficient to induce RA synovial macrophage- and monocyte-osteoclast differentiation in the absence of OPGL. This was evidenced by the formation of tartrate-resistant acid phosphatase (TRAP), vitronectin receptor, cathepsin K-positive multinucleated cells on glass coverslips and lacunar resorption pits on dentine slices. When IL-1alpha was added to this cultures together with TNF-alpha, the number of lacunar resorption pits were increased. It was found that anti-TNF-alpha inhibited osteoclast formation by RA synovial macrophages and monocytes and that although the number of TRAP-positive multinucleated cells was not changed, inhibition of pit formation was seen when anti-IL-1alpha was added to RA macrophage and monocyte cultures. OPG, however, showed no effect on osteoclast formation and activation induced by TNF-alpha and IL-1alpha.
Conclusion
This study has shown that TNF-alpha induces RA synovial macrophage- and monocyte-osteoclast differentiation and that IL-1alpha activates osteoclasts to resorb bone. This osteoclast formation and activation is independent of OPGL signalling system. The new mechanism, inflammatory bone resorption, may represent an important role in the RA joint destruction and osteoporosis.
References
Kobayashi K, Takahashi N, Jimi E, et al. Tumor necrosis factor alpha stimulates osteoclast differentiation by a mechanism independent of the ODF/RANKL-RANK interaction. J Exp Med. 2000;191: 275–86 Azuma Y, Kaji K, Katogi R, Takeshita S, Kudo A. Tumor necrosis factor-alpha induces differentiation of and bone resorption by osteoclasts. J Biol Chem. 2000;275:4858–64
We reviwed 24 cases treated by High Tibial Osteotomy (HTO) and Unicomparmental Knee Arthroplasty (UKA) for spontaneous osteonecrosis of the femoral medial condyle. The average age of patients at surgery was 62.4 years in the HTO group, and 75.5 years in the UKA group. Clinical evaluation was carried out for a mean follow-up period of 72 months in the HTO group, and 64 months in the UKA group. Pain on walking and in climbing stairs was remarkbly improved in both groups, but range of motion was slightly lost in the UKA group. Not only does UKA have a great effect on relieving pain with easier rehabilitation, it also is easily performed in eldery or poor risk patients because it is less invasive. We believe that UKA is a useful procedure in treating spontaneous osteonecrosis of the femoral medial condyle when it is performed with adequate patient selection and operative technique.
Fracture of the hook of hamate is a rare condition, with the patient usually complaining of local pain and swelling. This fracture is important because subcutaneous rupture of the flexor tendon sometimes takes place secondary to the fracture. We describe a case who had disturbance of active flexion of the ring finger.
Magnetic resonance imaging (MRI) has become an important diagnostic tool in diagnosing spinal cord tumors. But differential diagnosis is very difficult with only MRI.Spinal meningiomas account for about 10% of primary spinal cord tumors in Asia. We studied three patients with spinal meningiomas in order to show special findings. T1-weighted images showed various intensities, but their signal intensities on T2-weighted images were similar to those of the spinal cord in all cases. We considered these to be special findings with MRI in spinal meningioma. The relationship between pathological type (e. g. psammomatous type, fibroblastic type, and transitional type) and MRI was not clear. Preoperative diagnosis of ossified spinal meningioma was made from MRI.
We report a case of intramuscular myxoma occurring in the adductor brevis. A sixty-year-old man was referred to our hospital with a large soft tissue mass in the left thigh detected by abdominal CT. MR-imaging disclosed a large mass that was homogenous hypointense with respect to the adjacent muscle on T1-weighed image and hyperintense on T2-weighed image. The mass showed remarkable irregular postcontrast enhancement. We removed the tumor completely after the final diagnosis of intramuscular myxoma by open biopsy. Intramuscular myxomas are benign lesions both clinically and histologically, but may cause confusion in preoperative roentgenographic diagnosis if these are identified with unusual expression.
Solitary bone cyst is common in tubular bones. However, it is extremely rare in the spinal column. Only nine cases have been reported with histologically proved solitary bone cyst associated with the spine.A 23-year-old man was referred to our hospital complaining of lower back pain for 3 years. Roentgenograms disclosed a well-defined radiolucent lesion in the fourth lumbar vertebra. Computed tomography scan disclosed cystic lesion in the fourth lumber vertebral body spreading to the left pedicle and articular process. MRI of the lumbar vertebra demonstrated the lesion, that is iso-intensity with respect to the spinal cord on T1-weighted image, and hyperintensity on T2-weighted image.At operation, we curetted the lesion of the cystic cavity filled with bloody fluid by the transpedicular approach. Alkaliphosphatase (ALP) of the fluid was twice the serous ALP Level. Histological examination showed a thin layer of loose connective tissue with no rimming of the epithelial cells consisting of solitary bone cyst.
Geometric Total Knee Arthroplasty (TKA) has been in general use since 1972. With this design the tibial compornent was composed of resin only, and patella resurfacing was not considered necessary. Consequently, many patients complained of pain around the patello-femoral joint or revisited for failed tibial component postoperatively. At this time however, we found a case who experienced no pain around the patello-femoral joint, no osteoarthrotic change and no evidence of loosening on plain roentgenogram. We concluded that good results in Geometric type TKA can be achieved with thorough preoperative planning and adequate operative technique.
We performed subtotal sacrectomy for squamous cell carcinoma on the sacral area of a 48-year-old man suffering paralysis of lower extremities for 28 years. Although the resection of the total mass of carcinoma including most part of sacrum (S2-5) was successfully performed, the patient suffered from protracted bacterial infection of the pelvic cavity and osteomyelitis of iliac bone. He died of respiratory failure due to distant metastasis of the tumor to the lung 248 days after surgery. [Skin Cancer (Japan) 2001; 16: 265-2691]
