[The Department of Orthopaedics and Traumatology of the University Clinics of Brussels, Erasme Hospital]. / Le Service d'Orthopédie-Traumatologie des Cliniques Universitaires de Bruxelles, hôpital Erasme.

On the occasion of the thirty years since its inauguration, the Department of Orthopaedics and Traumatology of the University Hospital Erasme reviews the milestones of its development. Various original new techniques have been implemented: monitoring of implants using strain gauges, external fixation of the limbs, external minifixation, miniinvasive anterior approach in hip arthroplasty, knee ligamentoplasties, orthopaedic microsurgery and composite tissue allotransplantation. The care of aged patients takes place in close collaboration with the Department of Geriatrics. Two new clinical units have been created, the Unit of Hand and Peripheral Nerve Surgery, and the Centre for Sports. The Department has organized an efficient Bone Bank. The new day care hospital improves the possibilities of ambulatory surgery. The article details as well the activities of teaching and research of the members of the Department.

[Historical review of the treatment of fractures. Contribution of the Belgian surgery to the origin and development of osteosynthesis]. / Aperçu historique du traitement des fractures. Apport de la chirurgie belge dans la naissance et le développement de l'ostéosynthèse.

The word osteosynthesis was proposed by A. Lambotte in 1904. His definition, given in 1908, is still valid today: "Osteo-synthesis is the artificial contention of the bone fragments of fractures, by special devices acting directly on bones, exposed or not, with the aim to strongly fix them in their original position". The authors review the methods of contention before the invention of osteosynthesis and later the developments of bone fixation techniques. They insist in particular on the durable innovations of various pioneers including A. Lambotte, R. Danis, R. Hoffmann and G. Küntscher. The School of Brussels has been implicated in the developments and conceptualisation of osteo-synthesis.

[Effects of electric and electromagnetic fields on cell differentiation and application in orthopedic and trauma surgery]. / Effets des champs électriques et électromagnétiques sur la différenciation cellulaire et leur intérêt en chirurgie orthopédique et traumatologique.

The discovery of the dynamic electrical properties of bone is at the origin of the therapeutical application of the electromagnetic fields in Orthopaedics and Traumatology. The first empirical treatment of non-union, fresh fractures and osteonecroses allowed the observation of several effects which, without justifying a systematic clinical application, encouraged further fundamental research. The results of this work realized during 35 years are summarized in the present article. After exposure to specific electromagnetic fields, we observed a modification of the DNA activity and an increased production of RNA. During enchondral ossification, the amount of acid GAGS increased faster and the ossification of the primary ossification point is accelerated. On fresh fractures, the rigidity of the callus increased faster. Finally, the microarrays analyses show an upregulation of mRNA involved in cellular differentiation and proliferation. The mRNA responsible of the production of BMP-2 is significantly increased, explaining the main results observed after the expense of experimental models of the bond tissues. All the observed results are in favour of an acceleration of the cellular differentiation at the expense of the proliferation.

[Validation of a new in vivo measurement method to measure subsidence of a cemented Exeter femoral stem]. / Validation d'une méthode de mesure de l'enfoncement d'un implant fémoral cimenté de type Exeter.

PURPOSE OF THE STUDY: Total hip arthroplasty has become one of the most common procedures in orthopedic surgery. These patients must nevertheless be followed with care due to the risk of instability. Knowledge of early migration behavior can provide an indirect assessment of implant fixation. The purpose of this work was to develop a new measurement tool for early assessment of the femoral component. MATERIAL AND METHODS: We analyzed the x-rays of ten Exeter stems (Stryker-Howmedica) implanted between 1996 and 2001 using a simple software designed to calculate the vertical subsidence of each implant. The technical precision and inter-observer reproducibility were checked. RESULTS: The software provided a precision of 0.14-0.3 millimeters. The overall precision of the technique was 1.2 millimeters. There was no statistically significant inter-observer variability. We observed a mean subsidence of 1.3+/-0.7 millimeters at six Months, followed by no further migration. DISCUSSION AND CONCLUSION: This new method was found to be reliable. It is useful for identifying implant migration at different bone-cement-implant interfaces. The time course of subsidence appears to be important to determine threshold values for failure. This tool provides an easy-to-use method for both retrospective and prospective analysis. With minor modifications of the software program, this tool can be used for other types of implants.

Protracted systemic changes in bone biology after segmented unloading in the rat.

To investigate whether the decreased bone formation observed in most experimental situations of disuse was caused by an increased inhibition by the bone microenvironment of osteoblast (OB) proliferation, we studied the inhibiting power on ROS 17/2.8 proliferation of the bone marrow extracellular fluid (IPEF) in loaded and unloaded bones of rats submitted to two situations of partial disuse: tail suspension (TS) for 3 days to 2 weeks and around the knee tenectomy (KT) for 2-10 weeks. Histomorphometric parameters and osteoblast precursors dynamics were studied in parallel. Bone volume was lost in the unloaded bones, but not in loaded bones, in both experimental situations. Bone formation was low at early times (7-14 days) in TS rats. However, in KT at later times (4-10 weeks), the osteoblastic index of the unloaded tibia was increased. IPEF was not increased in the unloaded bones 3-7 days after TS. It was decreased later in the course of unloading (after 2 weeks of TS and 2-10 weeks after KT). This decrease was observed in the loaded bones as well. Unexpectedly, we also found that the number of FCFUs was decreased in both loaded and unloaded limbs in TS and KT, and that the yield of cells obtained in primary culture from tibial metaphysis was decreased in both tibiae from KT animals. These data show that an increased IPEF does not play a role in the early inhibition of bone formation responsible for the loss of bone after unloading in the TS model. Its later decrease could be permissive for the increased osteoblastic index observed in the KT model. They also show that, contrary to the usual assumptions, bone biology is changed all over the skeleton after partial unloading, even if the changes result in bone loss in the unloaded bones only. Thus, as yet, unidentified systemic factors probably superimpose on the local factors that control bone volume.

[The orthopedics-traumatology department]. / Le Service d'Orthopédie-Traumatologie.

The Department is involved in clinical and research activities. We pioneered the clinical application of "smart of Orthopaedic implants". The monitoring concept, bringing a high added value, helps in assessing fracture healing or implant fixation. The technique, featuring the 21st century, also requires advanced knowledge in biomaterials. Such implants have been used during the ESA Parabolic Flight Campaigns. These measurements are a prerequisite to establish prevention programs of the bone demineralisation during space flights but also in disuse osteoporosis. The Department is deeply involved in external fixation. In vitro studies of the mechanical insertion and holding parameters of external fixation pins have been performed to produce new implants, which efficiency has been proved by a clinical study. We defined original clinical principles of external fixation as its use in upper limb indications, to maintain microsurgery transplant, preserving devascularization and providing adequate fixation. Our biomechanical approach of the upper limb, now confirmed by others research groups, questioned old clinical concepts. The isokinetic evaluation assesses the dynamic function of articulations, i.e. after arthroplasty, and is also used for medico-legal evaluation. The clinical research touches orthopaedic (or systemic) diseases as algodystrophy, Kienböck disease, Kashing Beck. We conducted a multidisciplinary research on the effect of electromagnetic fields (EMF) on cells differentiation. In addition to possible healing properties, it helps as an objective support to analyse the exposure to the environmental EMF.

Histology of Kashin-Beck lesions.

There are few papers in existence describing the histopathology of Kashin-Beck disease. The few existing papers mention chondronecrosis within the epiphyseal primodium and metaphyseal cartilage. In the present study, two series of samples were available for histology: supernumerary fingers removed from young subjects and intra-articular bodies collected in more advanced cases of the disease. The prevailing characteristic of the samples is the absence of vascularisation within the proximal cartilage end plate of the phalanx associated with an alteration of the epiphyseal bone formation. These observations suggest that Kashin-Beck disease could develop from an alteration of the angiogenesis of the metaphyseal cartilage resulting in degeneration with consequent joint dysplasia, which may be associated with a decrease in growth of the diaphyseal bones.

Effects of low frequency pulsed electrical current on keratinocytes in vitro.

The effects of low frequency pulsed electrical current on epidermal repair in vitro were examined. Charge-balance current stimuli proposed for chronic wound treatment were tested on skin keratinocytes cultured at an air-liquid interface on dead human dermis. Results imply that the balance between proliferation and differentiation in electrically treated samples is significantly modified in favor of differentiation. More advanced differentiation, shown through epidermal histology, was obtained in cultures exposed to electrical current, whereas the culture growth, the result of keratinocyte migration and proliferation, was greater in control samples.

The diagnostic value of magnetic resonance imaging in non-traumatic osteonecrosis of the femoral head.

To assess the effectiveness of nuclear magnetic-resonance imaging in the detection of osteonecrosis of the femoral head, we studied the cases of twenty-five patients (forty-nine hips) in whom necrosis of the femoral head was suspected on the basis of plain radiographs, computed tomographic scans, radionuclide bone scans, and magnetic resonance-imaging scans. The results of these investigations were compared, for all except one patient, with the pathological findings of transtrochanteric core biopsies of the femoral head and neck of both hips. Of the forty-nine hips, thirty-three had histological proof of osteonecrosis. Twenty-two (67 per cent) of these hips showed definite necrosis on the plain radiographs; eighteen (62 per cent), on the twenty-nine available computed tomographic scans; twenty-four (77 per cent), on the thirty-one available radionuclide bone scans; and all of the hips, on the magnetic resonance-imaging studies. In six additional hips, there were histological changes (marrow necrosis, edema, hemorrhage, and fibrosis) in the medullary spaces without detectable osteonecrosis. The plain radiographs and computed tomographic scans of these six hips were normal except for the computed tomographic scan of one, and the radionuclide uptake on bone-scanning was abnormal in four of the six, as were the magnetic resonance-imaging studies. In the two hips that had normal magnetic resonance-imaging studies, the biopsies showed only destruction of fat cells in the medullary spaces, with no edema or fibroblastic reaction.(ABSTRACT TRUNCATED AT 250 WORDS)