Acute osteomyelitis and septic arthritis in children: a systematic review of systematic reviews

OBJECTIVE

Septic arthritis and osteomyelitis are rare in children, but they are difficult to treat and are associated with a high rate of sequelae. This paper addresses the main clinical issues related to septic arthritis and osteomyelitis by means of a systematic review of systematic reviews.

MATERIALS AND METHODS

The major electronic databases were searched for systematic reviews/meta-analyses septic arthritis and osteomyelitis. The papers that fulfilled the inclusion/exclusion criteria were selected.

RESULTS

There were four systematic reviews on septic arthritis and four on osteomyelitis. Independent assessment of their methodological quality by two reviewers using AMSTAR 2 indicated that its criteria were not consistently followed.

CONCLUSIONS

Collectively, these works provide strong evidence regarding a large number of issues including classification, epidemiology and risk factors, causative organisms, clinical presentation, laboratory markers, imaging, diagnostic needle aspiration, antibiotic therapy, surgical therapy, and prognosis. A clinical summary based on the best evidence is supplied.

Androgen receptors in Dupuytren's contracture

Palmar fascia tissue and cultured cells from patients with Dupuytren's contracture and from normal subjects were characterized and analyzed for androgen receptor expression. Androgen receptors have never been studied in Dupuytren's myofibroblasts and may have a role in its high male predominance. Surgical samples were collected from eight patients undergoing surgery for Dupuytren's contracture and from four patients with carpal tunnel syndrome, used as control tissue. Immunohistochemical analysis was performed on tissue samples and on cell cultures with anti-androgen receptor, anti-alpha-smooth muscle actin, anti-fibronectin, and anti-type I and III collagen antibodies using the biotin avidin peroxidase method as revelatory system. Immunostaining for androgen receptors in tissue samples and cultured cells revealed nuclear reaction in many Dupuytren's myofibroblasts, but in few fibroblasts of the normal palmar fascia. In a double-labeling study, androgen receptors were seen to co-localize with alpha-actin in both cell cultures and tissue samples. We present the first evidence that the palmar fascia is a target tissue for androgen action and that the expression of androgen receptors in Dupuytren's contracture is considerably higher than in the normal palmar fascia. Further studies will need to evaluate whether the androgen-responsive state of the tissue is related to the high incidence of Dupuytren's contracture in the male sex.

Characterization of cultured human ligamentum flavum cells in lumbar spine stenosis

To investigate the pathogenesis of the degenerative changes of the ligamentum flavum occurring in lumbar spine stenosis, yellow ligament cells from patients with lumbar spine stenosis were cultured for the first time and subjected to biochemical, histochemical and immunohistochemical study. Stenotic ligamentum flavum (SLF) cells were seen to express high levels of alkaline phosphatase (ALP) activity and to produce a matrix rich in type I and III collagen, fibronectin and osteonectin. The matrix mineralized only following beta-glycerophosphate (betaGP) and ascorbic acid supplementation. Stimulation with human parathyroid hormone (PTH) increased intracellular cAMP concentration. These findings indicate that there was significant evidence of osteoblast-like activity in these cells. SLF cells also stained for S100 protein, type II and type X collagen, and co-localized type II collagen and ALP labelling, reflecting the presence of hypertrophic chondrocyte-like cells. Cultures from control patients showed neither osteoblastic nor chondrocytic features: they expressed type I and type III collagen and fibronectin, but did not stain for osteonectin, nor were bone-like calcifications observed in presence or absence of betaGP. Normal ligamentum flavum (NLF) cells did not synthesized S100 protein or type II or type X collagen, and showed a weaker response to PTH stimulation. Our data demonstrated the presence of hypertrophic chondrocytes with an osteoblast-like activity in the ligamentum flavum of patients with spinal stenosis suggesting that they could have a role in the pathophysiology of the heterotopic ossification of ligamentum flavum (OLF) in lumbar spine stenosis.

Characterization of human bone cells in culture

Osteoblast-like cells isolated from human bone bioptic specimens were established in culture. Their osteoblast-like phenotype was studied by biochemical, histochemical and immunohistochemical methods and by electron microscopy examination. Third-passage cell cultures exhibited high level of alkaline phosphatase activity and the exposure to human parathyroid hormone produced an increase of intracellular cAMP. Cultured cells were immunoreactive for type I and type III collagen, osteonectin, and fibronectin; when ascorbic acid and beta-glycerophosphate were added, they synthesized a rich extracellular matrix. This characterization ensures the reliability of osteoblast-like cultures when they are used as experimental models.

Evidence of type II estrogen receptor in human osteoblast-like cells

Osteoblast-like cells isolated from human bone bioptic specimens were characterized and analysed for the presence of type II estrogen receptor (type II EBS). The amount of type II EBS was measured by a whole-cell assay at 4 degrees C for 2.5 h using [(3)H]-estradiol as tracer. Saturation analysis, used to investigate the binding characteristic of type II EBS, resulted in a sigmoid curve. Scatchard analysis showed the binding affinity of the estrogen receptor, yielding a concave plot. The dissociation constant (K(d)), determined from the [(3)H]-estradiol concentration required for half saturation was about 12+/-2 nM (SD). The number of type II EBS, estimated at maximum binding, was 197,000+/-8800 sites per cell. If the regulation of the receptor by flavonoids would be confirmed, the evidence of type II EBS in osteoblast-like cells could suggest a direct action of ipriflavone and others flavonoids on bone density in postmenopausal osteoporosis.

N,N-dicarboxymethyl chitosan as delivery agent for bone morphogenetic protein in the repair of articular cartilage

Bone morphogenetic protein (BMP), associated with N,N-dicarboxymethyl chitosan, is used to induce or facilitate the repair of articular cartilage lesions. This association is intended for the synergistic potentiation of the respective biological effects. Data show that BMP-7 enhances the in vivo proliferation of cells with chondrocytes phenotype in the articular environment, leading to partial healing of the articular surface of the lesions. N,N-dicarboxymethyl chitosan is found to be useful as a molecular carrier or drug delivery agent.

An experimental study in X-ray spectroscopy of the zirconium (Ca-PSZ) - bone interface. Microanalytic evaluation of the osteogenetic response

Ultrastructural difractometric and chemical evaluations of calcium partially stabilized zirconium (Ca-PSZ) implants were performed in an in vivo study on animals in order to evaluate its biological behaviour. The chemical-morphological investigations demonstrated the presence of an osteogenetic activity at the bone-biomaterial interface. The new-osteogenesis was preceded by the formation of a loose connective tissue around the implants. This mesenchymal-type tissue without a capsular organization, allowing modulation of the mechanical forces to which the implant is subject, could be considered a positive event in the osteogenetic process and not a sign of future failure of the implant. Finally, microanalytical investigations carried out on non-implanted and implanted Ca-PSZ tools suggested that the surface of this ceramic material does not undergo modification once it has been inserted in the biological environment (12 months).

Subungual exostosis of the foot

Eleven subungual exostoses of the foot (10 on the hallux, 1 on the third toe) were studied. The initial symptom was subungual pain. When a subungual mass of fibrous tissue appeared, the nail was pushed up and in one case the mass became infected. X-rays exhibited a bone mass protruding from the terminal phalanx on the dorsomedial aspect of the toe in all cases. All patients underwent surgical excision of the lesions with partial onychectomy. Three layers were identified in five cases: a cap of fibrous tissue, a middle zone of hyaline cartilage with enchondral ossification, and a deep zone of cancellous bone. In three other cases, the histological pattern was pleomorphic and poorly characterized. The study shows that most subungual bone masses exhibited the pathological features of conventional osteochondromas. Nonetheless, a small number of lesions were pleomorphic and differed from osteochondromas, with abundant fibrous tissue merging irregularly into scattered islets of cartilage that was not organized in columns. Radical excision of the mass achieved complete relief of symptoms and recovery without recurrences in all cases.

Distribution of elastic fiber types in the epiphyseal region

Three types of elastic fibers have been described: mature elastic fibers, elaunin fibers, and oxytalan fibers. To our knowledge, their location in the immature epiphysis has never been previously reported. The aim of the present study was to use histochemistry, immunohistochemistry, and electron microscopy to demonstrate the distribution of each type of elastic fiber in the epiphyseal region of growing humans and rabbits. Histological samples were collected from the knees of 10 immature New Zealand White rabbits and four children of various ages. The Weigert resorcin-fuchsin, Gomori aldehyde-fuchsin, Verhoeff iron haematoxylin, and Fullmer-Lillie methods were used for histochemistry; anti-elastin monoclonal antibodies, for immunohistochemistry; and tannic acid, uranyl acetate, and lead citrate stain, for transmission electron microscopy analysis. Elastic fibers were detected in the perichondrium, the epiphyseal vessels, and the outer and middle zones of Ranvier's groove. Their orientation was longitudinal in the outer zone and circumferential in the middle zone of the groove. Oxytalan fibrils (i.e., bundles of filaments of 10-12 nm in diameter that do not contain elastin) and elaunin fibers (i.e., filaments that cross discontinuous aggregates of elastin) were more plentiful in the middle zone and decreased with age, whereas mature fibers were more numerous in the outer zone and increased with age. This organization of elastic fibers seems to indicate an age-related process of maturation of the elastic network. The contribution of these fibers to the mechanical properties of the epiphyseal plate and to the growth process remains to be determined.

Fibrillogenesis in tendon healing: an experimental study

The aim of this study was the histochemical, immunohistochemical and ultrastructural analysis of reparative fibrillogenesis in experimental lesions of Achilles' tendon. Subtotal tenotomy of Achilles' tendon was performed in twenty Wistar rats. The scar tissue was analysed 2, 4, 7, 14, 21, 30, 45 and 60 days post-operatively. Histochemical, (resorcin-fuchsin, aldehyde-fuchsin, iron haematoxylin and Fullmer and Lillie's methods) immunohistochemical (antibody against collagen I, II and elastin) and ultrastructural analyses were performed. Three phases in the healing process were distinguished: 1) inflammatory, 2) proliferative, and 3) remodelling phase. The inflammatory phase was characterised by haematoma, fibrin deposition, inflammatory cells, fibroblasts, beginning of collagen fibrillogenesis (200-400 A ø fibrils) and oxytalan fibrils. The proliferative phase was characterised by angiogenesis and fibroblast proliferation. Collagen fibres displayed a random arrangement and had a diameter of 400-600 A. Immature elastic fibres reached maximum tissutal concentration. In the remodelling phase, hypocellularity, normal vascularisation, tendon crimps, collagen fibres (800-1,000 A ø), elastic fibres with increased elastin deposition and reduction in oxytalan fibres were observed. In the course of the healing process collagen and elastic fibre fibrillogenesis exhibited consistent quantitative and qualitative variations (i.e. differences in the type and diameter of fibrils). The present study suggests that, together with other matrix macromolecules, also elastic fibres (oxytalan, elaunin and mature) are synthesised in significantly higher amounts during reparative fibrillogenesis and play a role in cell-matrix interaction.

Age-related distribution of elastic fibers in the rabbit knee

The distribution and histochemical properties of elastic fibers in the knee of newborn, young, adult, and old New Zealand White rabbits were studied. In the growing rabbit, elastic fibers, especially oxytalan fibers, are abundant in the perichondrium and the fibrous layer of the periosteum. They are homogeneously distributed in tendons, ligaments, and menisci, and are absent in the epiphyseal cartilage and growth plate and at the enthesis. In mature rabbits, the articular capsule, the synovial membrane, the peritenon, the periosteum, the perimysium, and the perivascular connective tissue are rich with elastic fibers. They are rarer in the tendon and are absent at the enthesis, in bone and articular cartilage. In the meniscus, the fibers are distributed centripetally. The distribution of elastic fibers is probably related to the different functional role and biomechanical behavior of each tissue. Finally, the type of elastic fiber in the various tissues changes with age; younger animals have more oxytalan fibers than adult animals. A gradual process of maturation and specialization of the network of elastic fibers takes place with age.

Critical analysis of intramedullary nailing by the Ender method in the treatment of intertrochanteric fractures

A retrospective study was carried out to evaluate the results of intramedullary fixation by Ender nailing in the treatment of intertrochanteric fractures. During the period 1980-1989, 85 patients were treated with this method at the Orthopedic Department of the Università Cattolica in Rome. Evaluation of the cases took into account the patient's characteristics (age, sex, weight, height, obesity, previous or concomitant illness, level of autonomy, mental condition, type of fracture, time elapsed before operation and laboratory tests), details of the operation (length, accuracy of reduction and mechanical fixation stability, post-operative hospitalization period and general and local complications) and follow-up evaluation (X-ray examination, functional examination and evaluation of the results). Analysis of the observations showed that, although it induced less surgical trauma, internal fixation by the Ender method did not ensure a stable reduction, particularly with highly comminuted and basicervical fractures. As a result, the elective indication for this method should be restricted to stable intertrochanteric fractures, particularly in patients with a generally poor condition.

Clinical and pathological aspects of solitary spinal neurofibroma

Four cases are described of solitary spinal neurofibroma, a rare tumour of the spinal cord or nerve roots. Computerised tomography provided an accurate topographical definition of the tumour. Magnetic resonance imaging showed an increased T2-weighted signal and multiple areas of decreased T1- and T2-weighted signals centrally. The MR signals matched the histological examination which showed hyperplastic interfascicular connective tissue, pleomorphic cells, and tightly packed nerve fibres compressed by the surrounding loose connective tissue. Electron microscopy showed three types of cell: Schwann cells, fibroblast-like cells, and mast cells. The histological findings suggests that solitary spinal neurofibroma is a distinct pathological entity which could be diagnosed preoperatively from the MR images.

Polymethylmethacrylate-antiblastic drug compounds: an in vitro study assessing the cytotoxic effect in cancer cell lines--a new method for local chemotherapy of bone metastasis

An in vitro study was performed assessing the pharmacologic properties of polymethylmethacrylate (PMMA)-antiblastic agent (doxorubicin and cisplatinum) mixtures in normal and neoplastic cell lines cultures. The study's aim was to analyze the polymerization capacity of PMMA in the presence of doxorubicin and cisplatinum, the release of drug from the mixture, the kinetics of release, and the effect of the released drugs in normal and neoplastic cell cultures. Our data show that even at high concentrations neither doxorubicin nor cisplatinum inhibit the polymerization of PMMA. Moreover, mixtures in vitro can release the antiblastic drug which maintains its pharmacologic activity on sensitive neoplastic cells. Therefore, the PMMA-antiblastic drug mixtures, along with current anti-cancer therapy (systemic chemotherapy and radiation therapy), may provide better local control of the metastatic lesion and of some bone tumors.

[Evaluation of fracture healing with the computerized analysis of radiographic images]

The radiographic evaluation of fracture healing in the long bones utilizes subjective and hardly analytic standards. Therefore, to solve this problem, the authors suggest using a computerized image processing system which increases radiographic informative content and allows an objective evaluation of fracture healing. We analyzed the radiographs of 15 patients suffering from femoral fracture and treated by means of Küntscher nailing. We processed the radiographs taken both before and 1, 2, 4, and 6 months after surgical treatment. It was thus possible to select the regions of interest, to graph brightness levels and to measure both distances and areas. Computerized image processing provides an objective and quantitative analysis of radiographs and allows an increase in informative content. It also allows the comparison of pre- and postoperative radiographs with those taken at different times. Our results may confirm the utility of computerized image analysis of radiographs to evaluate bone remodelling during fracture healing.

The ultrastructure of schwannoma and neurofibroma of the peripheral nerves

An electron microscopic study of 4 solitary schwannomas and 2 neurofibromas of peripheral nerves was performed with the aim of investigating the debated histogenesis of the two types of lesion. Our observations confirm that solitary schwannoma is composed almost exclusively of cells with characteristics of differentiated Schwann cells, thus providing evidence for a neuroectodermal origin of the tumor. Analysis of the ultrastructure of neurofibroma shows the presence of 3 different types of cells: Schwann-like cells, perineurial-like cells, and fibroblast-like cells. Perineurial-like cells were prevalent in our observations. These findings as well as the many controversial aspects of the origin of neurofibroma could be explained by separating this type of neoplasia into two pathological forms: perineurial and interstitial. Moreover, the numerous differences between solitary schwannoma and neurofibroma allow us to hypothesize a different cellular origin for each tumor. If confirmed by further observations, this would explain the difference in the capacity of the two types of neoplasia to undergo malignant change, an occurrence almost unknown in solitary schwannoma yet relatively common in neurofibroma.

Fibrin-antibiotic mixtures: an in vitro study assessing the possibility of using a biologic carrier for local drug delivery

An in vitro study assessing the kinetics of drug release from antibiotic-fibrin seal compounds and the antibacterial efficacy of the delivered drug has been performed. Antibiotic sensitivity and the amount of drug released was measured by means of agar diffusion test. Standard and experimental curves were established for each antibiotic and each bacterial test in order to evaluate the quantities of the drug released during each 24 h period. The reconstitution of lyophilized human fibrin with an aqueous solution containing an antibiotic resulted in only minor modification of the clotting process, with the exception of those solutions containing cefotaxim and mezlocillin which failed to clot altogether and were excluded from further study. The evaluation of the kinetics of elution of the antibiotics from the fibrin clots showed that all of the antibiotics had been almost completely released by 96 h. The delivered amount of each drug was enough to maintain the Minimal Inhibitory Concentration (MIC) until the 4th day of culture for the most of antibiotics, resulting in a prolonged release of the drug.

Morphological changes in growth-plate cartilage in osteogenesis imperfecta

We obtained specimens of growth-plate cartilage from four patients with osteogenesis imperfecta. Light microscopy showed structural changes in the tissue and morphological changes in chondrocytes and matrix, particularly in the hypertrophic zone. There were changes in the process of calcification in the primary mineralisation zone of the cartilage. We also found histochemical changes in the matrix glycosaminoglycans (GAGs) in the zones where physiological mineralisation was disturbed and where the trabeculae were interrupted and poorly mineralised. In addition to the known molecular defects in collagen, changes in GAGs and non-collagenous proteins are important factors in the pathogenesis of the disease.

Biological aspects of repair osteogenesis in corticospongy homologous grafts

An experimental study was carried out aimed at studying the short-term, mid-term and long-term biological features of the incorporation of homologous bone grafts. Homologous cortical and corticospongy grafts of the proximal third of the tibia were implanted in 60 adult New Zealand rabbits, under general anaesthesia. The animals were sacrificed after predetermined periods of time, and the tibia removed for radiographic and histological examination. An analysis of the different phases of the fusion process allowed us to observe the different dynamic evolution of osteogenic repair of cortical as compared to spongy grafts. This could be explained by the different tensile properties of the two types of grafts.

Growth-plate cartilage metabolic response to mechanical stress

An in vitro study assessing the metabolic response of growth-plate cartilage explants to mechanical stress was performed. Cultured explants were exposed to two types of stress: (a) single high-compressive force (SHC), and (b) multiple intermittent low-compressive force (MILC). Proliferative activity and matrix synthesis were determined with liquid scintillation counting after explants were labeled with [3H]thymidine and [35S]-sulfate. Our in vitro findings suggest that too high a force, even acting for a short time, may result in permanent injury of growth plate cartilage. Hence, we hypothesized that there might be an unknown pathogenetic mechanism of Salter's fifth-type epiphyseal injury. We report the results of our study.

Experimental investigation into reparative osteogenesis with fibrin adhesive

An experimental investigation was carried out in order to evaluate the effects of fibrin adhesive on the reparative osteogenesis of bone grafts in the short, medium, and long term. Sixty fully developed New Zealand White rabbits under general anesthesia were grafted with homologous bone tissue in the proximal third of each tibias. Fibrin adhesive was used in one hind limb only. The animals were killed at a predetermined time. Both tibias were removed and subjected to radiographic and histologic analyses. The reparative process was observed and the differences between the fibrin adhesive-treated grafts and the reference group in the first few weeks were determined. No substantial difference was detected in the reparative osteogenetic process of the graft in the animals killed after 2 months.