Solitary Bone Plasmacytoma of Humerus Presenting as a Nonhealing Fracture in a Child: A Rare Entity.

Solitary bone plasmacytoma is an extremely rare entity and is characterized by localized proliferation of monoclonal plasma cells. Plasmacytomas are extremely rare in the pediatric population. The median age at diagnosis is usually the fifth or sixth decade, with axial skeleton being more commonly involved than appendicular. We hereby, report the case of a 13-year-old boy with solitary bone plasmacytoma of the right humerus. Though extremely rare in the pediatric age group, plasmacytomas may be considered as one of the remote differentials in children presenting with solitary bone tumors.

Elevated levels of macrophage colony-stimulating factor in human fracture healing.

Macrophage colony-stimulating factor (M-CSF) plays a unique role in bone remodeling. However, to our knowledge, no data on the role of M-CSF in fracture healing in humans have been published so far. This study addressed this issue. One hundred and thirteen patients with long-bone fractures were included in the study and divided into two groups, according to their course of fracture healing. The first group contained 103 patients with normal fracture healing. Ten patients with impaired fracture healing formed the second group of the study. Volunteers donated blood samples as control. Serum samples were collected over a period of 6 months, following a standardized time schedule. In addition, M-CSF levels were measured in fracture hematoma and serum of 11 patients with bone fractures. M-CSF concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Fracture hematoma contained significantly higher M-CSF concentrations compared to M-CSF concentrations in patient's serum. M-CSF levels in fracture hematoma and in patient's serum were both significantly higher than M-CSF concentrations measured in serum of healthy controls. Highly elevated M-CSF serum concentrations were found in patients with physiological fracture healing over the entire observation period. Significant differences in the M-CSF serum concentration between patients with normal fracture healing and patients with impaired fracture healing were not observed. This study indicates, for the first time, to our knowledge, a possible local and systemic involvement of M-CSF in humans during fracture healing.

Radiocalcium absorption is reduced in postmenopausal women with vertebral and most types of peripheral fractures.

Intestinal calcium absorption accounts for 60% of the variance in calcium balance and is therefore a potentially very important determinant of bone status. Whether measured by the balance technique or with radiocalcium, it is known to be significantly reduced in postmenopausal women with vertebral and hip fractures. By contrast, there is very little information about calcium absorption in other types of postmenopausal fracture. We now report a series of 549 untreated, Caucasian postmenopausal women in whom we recorded prevalent fractures, measured radiocalcium absorption, and obtained radiographs of the lateral thoracic and lumbar spine. Of these women, 172 had no prevalent fractures, showed normal spine radiographs, and served as controls; 72 had one or more peripheral fractures but normal spine radiographs; 147 had one or more wedged or crushed vertebrae but no peripheral fractures; and 158 had a history of peripheral fracture and one or more fractured vertebrae. Age-adjusted radiocalcium absorption was significantly lower in the two groups with spinal fractures than in the controls ( P<0.001) but not in the group with peripheral fractures only. It was also lower in the cases with more than two spinal fractures than in those with two or less (P<0.001). In respect of peripheral fractures, the greatest age-adjusted absorption deficit was found in fractures of the humerus (35%) followed by hip (32%), spine (21%), wrist (19%), and rib 17% (all significant but not significantly different from each other). Lesser deficits in tibia, ankle and foot fractures were not significant but type 2 errors could not be excluded. We conclude that impaired calcium absorption is particularly associated with those fractures for which osteoporosis is a significant risk factor.

Expression and activation of the BMP-signaling components in human fracture nonunions.

BACKGROUND: The potential use of bone morphogenetic proteins (BMPs) to promote bone-healing is of great interest to orthopaedic surgeons. Although the complex mechanism leading from the local presence of BMP (whether endogenous or exogenous) to bone formation is increasingly understood, limited information is available as to whether endogenous BMPs, their receptors, or other molecules involved in their signal transduction, such as Smad1, are present or disappear during the development of fracture nonunions. The purpose of the present study was to determine, by immunohistochemical analysis, whether BMPs, BMP receptors, or Smad1 disappear from tissues during the development of a fracture nonunion. METHODS: Twenty-one patients (average age, sixty-one years; range, thirty to eighty-five years) with a delayed union (four patients) or a nonunion (seventeen patients) were included. The average duration of the delayed union or nonunion was twenty-two months (range, 3.5 to 120 months). With use of immunohistochemical analysis, we studied the localization of BMP-2, BMP-4, and BMP-7 and their receptors BMPR-IA, BMPR-IB, and BMPR-II as well as pSmad1. With use of a pSmad1 antibody, we also studied whether the BMP receptors that were expressed were activated. RESULTS: The immunohistochemical localization of all seven BMP-signaling components was demonstrated in seventeen (81%) of the twenty-one patients. The remaining four patients lacked one or more of the components. Areas of newly formed bone had the highest percentage of positively staining cells, with the staining generally decreasing in areas remote from bone formation. However, even in areas of dense fibrous tissue and in specimens that lacked newly formed bone, immunostaining was still present. The staining patterns showed co-localization of the BMP-2, BMP-4, and BMP-7 proteins with the BMP receptors. The presence of pSmad1 signified the activated state of the BMP receptors, which implies that the BMP signal is transduced inside the cell.

Sustained-release microcapsules of a bone formation stimulant, TAK-778, for local injection into a fracture site.

The benzothiepin derivative (2R,4S)-(-)-N-(4-diethoxyphosphorylmethylphenyl)-1,2,4,5-tetrahydro-4-methyl-7,8-methylenedioxy-5-oxo-3-benzothiepin-2-carboxamide (TAK-778) is a potent bone formation stimulant. A sustained release formulation was prepared by encapsulating the drug into biodegradable microcapsules for local application to fracture repair in rats. The microcapsules consisted of TAK-778 (10% w/w) and a biodegradable polymer, copoly (d,l-lactic/glycolic acid), with a copolymer ratio of 85:15 (mol/mol) and an average molecular weight of 15 k. The TAK-778 amount at the injection site progressively diminished for 4 weeks after administration, and the serum level of TAK-778 was sustained over the same period. The local concentration of TAK-778 after administration of the microcapsules was simulated by a two-compartment open model. In the model, a first-order release rate constant and a transfer rate constant were obtained from the release profile of the microcapsules and the serum level of TAK-778 after administration of the TAK-778 solution, respectively. Localization at the injection site was examined by radiography using microcapsules in which iodoform was encapsulated as a contrast agent. The microcapsules formed a clot at the injection site, and their spread was narrowly restricted. The local concentration was calculated to be maintained within the range 10(-3)-10(-6) M over 4 weeks on the assumption that the dose and spread volume were 5 mg of TAK-778/site and 3 mL, respectively.

Microstructural features of non-union of human humeral shaft fracture.

Microstructures of non-unions of human humeral shaft fractures were investigated by using scanning electron microscopy, transmission electron microscopy, and X-ray microdiffraction. The non-union has a trabeculae structural framework similar to woven bone. Among the trabeculae are cavities that are subdivided into small chambers by thin plates of collagen fibrils. Some chambers are filled with variously shaped mineralized particles several micrometers in size. The collagen fibrils in both the trabeculae and the thin plates were only slightly mineralized by hydroxyapatite. Vesicles loaded with noncrystalline calcium phosphate (NCP) were observed in most mineralized particles, and brushite crystals with special morphology were seen to be embedded in some particles in irregular shapes. X-ray microdiffraction results indicated that the mineral phases in the non-unions were mainly NCP in addition to small amounts of hydroxyapatite and brushite. NCP deposition and insufficient mineralization of the collagen fibrils may be two important microstructural features of the non-unions of human humeral shaft fractures different from normally repaired bone callus.

[Several indicators of oxidative processes in fractures of the long bones]. / O nekotorykh pokazateliakh okislitel'nykh protsessov pri perelomakh dlinnykh kostei.

The authors have observed 55 patients with fresh fractures, with disturbances in consolidation (delayed consolidation, non-union of fractures, false joints) and with defects of diaphyses of the long bones. In the fracture area the dynamics of oxidation-reduction potential (ORP) was studied and volarographic investigations (determination of the volumetric speed of the local blood flow by hydrogen, a test with oxygen load) were carried out. Certain correlation between the quantity and the dynamics of the values under study and the state of the consolidation process was established. Coincidence of the dynamics of ORP and the local blood flow, presence of the quantity of volumetric speed of the local blood flow of 25-30 ml/min per 100 g of tissue with rather high ORP and a positive test under oxygen load in the polarographic study were prognostically favourable. The applied methods allow to control the course of the process of consolidation of the fragments and to a certain extent prognosticate the results of treatment of the patients with fractures of the long bones.

Parathormone, calcitonin, and vitamin D metabolites during normal fracture healing in geriatric patients.

In order to study the role of calcium-regulating hormones during callus formation in elderly patients, serum levels of parathormone (PTH), calcitonin (CT), 25-hydroxyvitamin D [25-OH-D], 1,25-dihydroxyvitamin D [1,25(OH)2D], 24,25-dihydroxyvitamin D [24,25(OH)2D], and calcium (Ca) were determined in 41 patients with fractures of long bones, primarily hip fractures. The parameters were measured on admission and after eight weeks. There were almost no changes in hormone serum levels during bone repair, except for a decrease in serum levels of 1,25(OH)2D from 25.3 +/- 2.3 pg/ml on admission to 21.0 +/- 2.0 pg/ml eight weeks later (p less than .001). Patients with fractures compared to normal elderly humans have lower serum levels of PTH (0.99 +/- 0.06 ng/ml versus 1.88 +/- 0.34 ng/ml; p less than .001), 25-OH-D (10.7 +/- 1.0 ng/ml versus 17.1 +/- 1.8 ng/ml; p less than .001), and Ca (9.1 +/- 0.1 mg% versus 9.7 +/- 0.1 mg%; p less than .001) and higher serum levels of 1,25(OH)2D (25.3 +/- 2.3 pg/ml versus 17.1 +/- 2.3 pg/ml; p less than .001). Female patients have lower serum levels of 24,25(OH)2D compared to males (1.65 +/- 0.15 ng/ml versus 2.06 +/- 0.29 ng/ml; p less than .05). A similar trend was noted in serum CT levels during callus formation (0.12 +/- 0.02 ng/ml versus 0.16 +/- 0.02 ng/ml; p less than .05). Patients with subcapital fractures of the femur have significantly lower serum levels of all vitamin D metabolites on admission, compared with patients suffering from extracapsular fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

[Changes in the amount of mineral components in bone tissue during treatment of transcondylar fractures of the humerus]. / Izmenenie kolichestva mineral'nykh komponentov kostnoi tkani pri lechenii chrezmyshchelkovykh perelomov plecha.

In 12 non-inbred 4-month-old puppies a closed brachial transcondylar fracture has been performed. By means of photonic absorbtiometry contents of mineral components have been estimated in the regenerate forming between the osseous broken pieces, in the osseous fragments and in the adjoining segment, depending on duration of the joint fixation during the treatment. Mineralization takes place more quickly in a mobile joint. Fixation for 5-7 days does not essentially affect the miniralization rate. Fixation for 14 days decreases intensity of the mineralization, produces deminiralization in the osseous pieces and in the adjoining segment of the bone, results in incompleteness of the brachial condyle rearrangement.

Bone mineral content in the forearm after fracture of the upper limb.

The bone mineral content was measured by gamma absorptiometry in patients who had sustained fractures of the upper limb. Measurements were taken on the shafts of the forearm and in the trabecular bone immediately proximal to the wrist. Fractures of the surgical neck of the humerus and fractures of the shaft of the humerus did not significantly influence the bone mineral content of the ipsilateral forearm. Fracture of the radius and the ulna, however, caused a 15% loss of the bone mineral content in the trabecular bone proximal to the wrist, whereas the mineral content on the shafts of the fractured forearms increased or decreased depending on the fracture site. The findings suggest that measurements of bone mineral content of the forearm are not necessarily invalidated if there has been a fracture of the same limb. Only if the forearm itself is fractured should measurements on this site be avoided.