Qualitative and quantitative analysis of post-operative drainage: pilot study.

Surgical drains can be placed after an operation to collect postoperative blood loss. However, these could be overestimated. Indeed, the fluid elapsed after the first postoperative day would no longer be pure blood. An early withdrawal of redon could then be considered. A monocentric prospective study of 25 patients undergoing total knee or primary hip replacement surgery, for osteo-arthritis, was conducted. Redon flow was evaluated in total volume and in composition by the sedimentation study. A qualitative analysis of the content of the redon was also carried out. To compare the elements found in the drained liquid with the blood data, a preoperative and two postoperative blood samples were taken. 18 TKA and 7 THA were included. A qualitative analysis of the postoperative flow of 11 TKA and 5 THA was requested. Decreases of sedimentation volumes and protein levels were found in the drained liquid compared to the blood for both TKA and THA. Our results tend to prove that on postoperative D1, the liquid drained in the redon would be blood, but that the liquid drained on D2 and D3 would be a mixture of blood and serum. Therefore, the real postoperative blood loss would be overestimated.

[Ballistic concepts and management of gunshot wounds at members]. / Notions de balistique et prise en charge des plaies par balle au niveau des membres.

Ballistic trauma is not the prerogative of battlefields and currently extends to civil environments. Any surgeon or emergency room can be faced with such trauma whose management requires an understanding of wound ballistics. The aim of this retrospective is reviewing the management of ballistic trauma within the C.H.U. Saint-Pierre hospital over a period of ten years. Data recorded included demographics data, lesions, clinical parameters, imaging, treatment and outcome. It appears that the wounds of the members have a low mortality rate but a significant rate of complications. Patients should be managed according to the ATLS protocol and according hemodynamic stability and location of the injury, benefit from imaging. Unstable patients will be operated in emergency, stable patients will be treated according to the extent of damage and the type of fracture either conservatively or by external fixator and intramedullary centromedullary. Debridement and antibiotics are recommended as a nerve exploration if there is a peripheral paralysis. The management of trauma in our sample appear not optimal in light of the literature especially in terms of setting the vascular point of debridement, antibiotic and nerve repair resulting in significant consequences. Two management protocols according to patients' hemodynamic status are offered.

La traumatologie balistique n'est pas l'apanage des champs de bataille et s'étend actuellement de plus en plus aux milieux civils. Tout chirurgien ou urgentiste peut se trouver confronté à de tels traumatismes dont la prise en charge est spécifique et nécessite notamment une connaissance en balistique lésionnelle. Cette étude consiste en une revue rétrospective de la prise en charge des traumatismes balistiques au sein du C.H.U. Saint-Pierre sur une période de dix ans. Les données démographiques, lésionnelles, cliniques, d'imagerie, de traitement et de suivi ont été collectées. A l'analyse des dossiers, il ressort que les plaies des membres ont un faible taux de mortalité, mais un taux de complications non négligeable. Les patients doivent être pris en charge selon le protocole ATLS puis selon la stabilité hémodynamique et la localisation du traumatisme, bénéficier d'une imagerie. Les patients instables seront opérés en urgence sans imagerie, les patients stables présentant des traumatismes osseux seront traités selon l'importance des lésions et du type de fracture soit de manière conservatrice, soit par fixateur externe ou enclouage centro-médullaire. Un débridement et une antibiothérapie sont recommandés ainsi qu'une exploration nerveuse s'il existe une paralysie périphérique. La prise en charge des traumatismes dans notre échantillon n'apparait pas optimale à la lumière de la littérature notamment en termes de mise au point vasculaire, de débridement, d'antibiothérapie et de réparation nerveuse. Deux protocoles de prise en charge selon l'état hémodynamique du patient sont proposés afin d'optimaliser la prise en charge.

[Evolution of low back pain after bariatric surgery]. / Evolution des douleurs lombaires après chirurgie bariatrique.

Although frequently called to mind by physicians, the relationship between overweight and low back pain is poorly understood and remains controversial. The present study aims to evaluate the evolution of low back pain in 65 patients planned for a bariatric surgery. The patients were enrolled prospectively. 54 patients (80%) could be evaluated 5 months after the procedure, and 47 patients (72%) were evaluated 22 months after surgery. Mean weight loss was 19 ± 9 kg (P < 0.001) at 22 months post-op. Patients demonstrated a statistically significant improvement of the NRS, Oswestry and SF-36 scores. This study suggests that low back pain might be reduced following bariatric surgery. However, the lack of dose-response effect is against a causal relationship between low back pain and obesity. Larger randomised controls are needed to determine a causal relationship.

[Treatment of osteoporotic fractures. A new approach by vertebroplasty and kyphoplasty]. / Traitement des fractures ostéoporotiques. Apports de la vertébroplastie et de la cyphoplastie.

Osteoporosis is a systemic disease and results in progressive bone mineral loss and concurrent change in bone architecture that leave bone vulnerable to fracture. In one third of patients with acute vertebral fracture, severe pain and limited mobility persist despite appropriate nonoperative management. Vertebroplasty is a minimally invasive method that involved the percutaneous injection of cement into a collapsed vertebral body to stabilize the fractured vertebra. The indication of this technique is a painful fracture after 8 weeks of conservative treatment. Contraindications include coagulopathy, absence of facilities to perform emergency decompressive surgery, a vertebral collapse greater than 65 % and a fracture of the vertebra posterior wall. The procedure results in quick, effective pain relief and complications as epidural leakage or thermal necrosis by cement extravasation are rare. Vertebroplasty does not expand the collapsed vertebra. Kyphoplasty is a modification of this first technique and offers potential advantages as lower risk of cement extravasation and better restoration of the vertebral body height. A cannula is introduced into the vertebral body via a transpedicular approach like for the vertebroplasty technique but it is followed by insertion of an inflatable bone tamp, which when deployed reduces partially the compression fracture. This then creates a cavity to be filled with bone cement. Considering the higher rates of morbidity or mortality that is associated with osteoporotic fractures, early mobilization in these patients is of prime importance and can be achieved by using each of this two techniques with a relative low complication rate.

Bone morphogenetic protein 7 in the treatment of congenital pseudarthrosis of the tibia.

We describe a 13-year-old boy with atrophic tibial pseudarthrosis associated with neurofibromatosis who had undergone nine unsuccessful operations. Eventually, union was obtained by the use of bone morphogenetic protein 7 in conjunction with intramedullary stabilisation and autologous bone graft.

Use of an intramedullary hip-screw compared with a compression hip-screw with a plate for intertrochanteric femoral fractures. A prospective, randomized study of one hundred patients.

One hundred elderly patients who had an intertrochanteric femoral fracture were randomized to treatment with a compression hip-screw with a plate (fifty patients) or a new intramedullary device, the intramedullary hip-screw (fifty patients). All patients were followed prospectively for one year or until death. A detailed assessment of the functional status and the plain radiographs of the hip was performed one, three, six, and twelve months postoperatively. The two treatment groups were strictly comparable. The operative time needed to insert the intramedullary hip-screw was significantly greater than that needed to insert the compression hip-screw with the plate (p = 0.02), but use of the intramedullary hip-screw was associated with less estimated intraoperative blood loss (p = 0.011). The prevalence of perioperative complications, such as bronchopneumonia, cardiac failure, and urinary tract infection, was comparable in the two treatment groups. There were one intraoperative fracture of the femoral shaft and two intraoperative fractures of the greater trochanter in the group managed with the intramedullary hip-screw. One patient had pulling-out of the compression hip-screw on the seventh postoperative day. Four patients had a trochanteric wound hematoma, without infection, after insertion of an intramedullary hip-screw. All but one of the fractures healed. The one non-union, which was in a patient who had a compression hip-screw, was treated with a hemiarthroplasty. The mortality rate was similar in the two treatment groups. The patients who had an intramedullary hip-screw had, on the average, significantly better mobility at one (p < 0.0001) and three months (p = 0.0013) postoperatively. This difference was no longer seen at six and twelve months, although the patients who had an intramedullary hip-screw still had significantly better walking ability outside the home at those time-periods (p = 0.05). The compression hip-screw was removed from two patients because of pain in the mid-portion of the thigh, which had begun after consolidation of the fracture. Fourteen patients who had an intramedullary hip-screw had cortical hypertrophy at the level of the tip of the nail at twelve months postoperatively. Cortical hypertrophy was significantly related to the use of two interlocking screws (p = 0.02). Six of these patients also had pain in the mid-portion of the thigh, and the nail had been locked with two screws in five of them. Three of the six patients had the hardware removed because of the pain, and the symptoms resolved. A seventh patient had pain without cortical hypertrophy. The intramedullary hip-screw device was associated with significantly less sliding of the lag-screw and subsequent shortening of the limb in the region of the thigh (p = 0.012 and 0.019, respectively); these differences were more pronounced when the unstable fractures in the two treatment groups were compared (p < 0.001).

Radiocarpal articular pressures during the reduction of distal radius fractures.

OBJECTIVES: To measure in vivo radiocarpal articular pressures during closed reduction and external fixation of distal radius fractures. DESIGN: Intraoperative measurements using a sterile pressure sensitive sensor specially constructed for this application. SETTING AND PATIENTS: Ten patients with a closed distal radius fracture stabilized by radiometacarpal external fixation. Radiocarpal pressures measured during transarticular distraction, wrist palmar flexion, wrist ulnar inclination, and fracture reduction. MAIN OUTCOME MEASUREMENTS AND RESULTS: Transarticular distraction resulted in a substantial decrease of the articular pressure, averaging -158.1 mmHg. Palmar flexion resulted in a mean pressure increase of 91.8 mmHg. The reduction of the fracture using a combination of distraction, palmar flexion and ulnar deviation resulted in either an increase or decrease of articular pressure, but always with a tendency toward progressive normalization of the pressure, with a mean slope of 3.2 mmHg/min. CONCLUSIONS AND CLINICAL RELEVANCE: The phenomena leading to the reduction of distal radius fractures could be related in part to a decrease of the intraarticular pressure, which may be responsible for a suction effect on the intraarticular bone fragments.

Analysis of the capital femoral line orientation. A CT scan study.

An accurate knowledge of the relationship between the neck and the epiphyseal plate at the end of growth is important for biomechanical investigations of femoral neck remodelling during childhood. Statistical data about the position of the epiphyseal femoral cartilage in relation to the neck axis at the end of the growth, are rare in the literature. As the trace of the epiphysis can be observed on a CT scan view of an adult hip, cadaver femurs were investigated to study this relationship and to avoid irradiation of children. The mean anteversion angle of the epiphyseal line towards the patient's coronal plane is 2.3 degrees. The plate is retroverted in an average of 8.2 degrees in relation to the neck axis and is related to neck anteversion. The more the neck is anteverted, the more the plate is retroverted.

[Analysis of the acetabulum anterior cover]. / Etude du recouvrement antérieur de l'acétabulum.

PURPOSE: The false profile X-Ray view as described by Lequesne, allowing the measurement of the anterior cover of the acetabulum, is a slantwise view obtained by a 65 degrees inclination of the pelvis on the radiographic plate. The errors introduced by this radiological measurement of the anterior cover are evaluated. MATERIALS AND METHODS: An anatomical and radiological analysis is conducted on 20 acetabula. The anterior cover is measured on the bone and the A point, the anterior extremity of the acetabular roof, is plumbed. Each pelvis is imaged following the Lequesne method. The VCA angle is measured with the radiological point A described by Lequesne and with the metallic point A as reference. RESULTS: The difference between the anatomical and radiological values of the anterior cover is an average by 11 degrees and undervalues the anatomical value. The deviation is reduced by the application of a trigonometrical formula. A difference between the radiological localisation of A point described by Lequesne and the metallic marker is pointed out. This difference increases when the acetabulum becomes dysplasic. CONCLUSION: The acetabular anterior cover measured with the radiological incidence described by Lequesne undervalues the real value. Moreover, the error increases when the acetabulum is dysplasic.

[Study of cotyloid anteversion by coxometric measurement]. / Etude de l'antéversion cotyloïdienne par mesure coxométrique.

A coxometric evaluation is helpful for the diagnosis and the prognosis of hip dysplasia. These measurements also given an intrinsic guide to the surgeon for total hip arthroplasty. A coxometric protractor is drawn on the majority of the goniometers and allows the measurement of the angle of internal and external roof, the angle of the acetabular roof obliquity and the femoral neck-shaft angle on a hip AP X-ray. The purpose of this report is to demonstrate that on the same X-ray, the adequate placement of the coxometric protractor allows to calculate the inclination angle, the acetabular anteversion angles and the anterior roof angle.

[Malignant transformation of chronic osteomyelitis and its scar tissue: apropos of 3 cases]. / Transformation maligne des ostéomyélites chroniques et des escarres: à propos de trois cas.

Three cases of malignant transformation into an epidermoid epithelioma at the site of osteomyelitis, two of the tibia and one of the sacrum, are presented. A review of the literature concerning this rare problem has been made. A larger series of cases is assembled from small series and several case reports found in the literature.

Biomechanical evaluation of Hackethal's intramedullary bundle pin fixation of humeral neck fractures.

Humeral neck fractures can be stabilized using a bundle of intramedullary pins as described by Hackethal. In order to decrease the risk of pin migration, packing of the medullary cavity with as many pins as possible is sometimes recommended, but others believe that stability can be decreased by destruction of cancellous bone in the humeral head by a large bundle of pins. A surgical neck fracture was created with a saw in 30 frozen cadaveric humeri. Bone quality was evaluated by radiography and densitometry. Fractures were stabilized using Hackethal's technique of retrograde intramedullary pinning with varying numbers of 2.5-mm diameter pins; increasing torsion or bending moments of force were then applied to the bones studied. Stability was found to improve with an increasing number of pins and with higher humeral head density. Based upon these findings, the use of a large number of pins is recommended to reduce the risk of pin migration. Up to eight pins, the risk of destruction of cancellous bone in the humeral head appears very low.

A method to measure acetabular cup anteversion after total hip replacement.

The authors propose a simple and practical method to measure radiologically the angle of ante- or retroversion of the acetabular cup using a goniometer. It only necessitates an anteroposterior radiograph centered on the femoral head and another one centered on the public symphysis. Special x ray equipment, compass, conversion table, mathematical formulas, or a pocket calculator are not required. The opening of the prosthetic cup is projected on the film as an ellipse. According to the rules of descriptive geometry, the true size of the angle of anteversion is easily obtained. The geometric constructions consist in drawing four lines. The adequate positioning on a hip radiograph of the protractor, drawn on the goniometer, permits the direct reading of the true and planar anteversion angles of the cup.

Histopathology of a well-functioning hydroxyapatite-coated femoral prosthesis after 52 months.

A fully hydroxyapatite-coated femoral implant was retrieved during autopsy. This component, provided with a bipolar femoral head, had been inserted for a displaced fracture of the femoral neck 52 months before. Osseointegration of the implant was evident, without any formation of fibrous tissue :39.9% of the perimeter of the prosthesis at the level of its proximal third was interfaced with bone (62.8% at the mid-third and 65.2% at the distal third). Remodeling of bone had ensued. Deposition of bone was most prominent in the calcar zone, along the medial and lateral aspects and around the tip. Proximally, cortical porosity was found to be increased by 73%, whereas medullary bone porosity was increased by a factor of 2. Cell-mediated resorption of the coating was systematically present in these bone remodeling areas. The average thickness of the coating was respectively 10.8, 50.2 and 151.2 microns in the proximal, mid- and distal thirds of the implant. Formation of new bone was often coupled with resorption. No debris from the coating was found in the joint tissues or in the articulating surface of the polyethylene insert. These overall histopathological features support mechanical stability of the implant and active remodelling of bone along with focal removal of HA coating associated with osteoclastic activity. No side effects from coating degradation could be demonstrated.

[Contribution to the study of pelvic stress during weight-bearing. Role of the pubic branch and trabecular bone]. / Contribution à l'étude des contraintes du bassin en charge. Rôle de la branche pubienne et de l'os spongieux.

INTRODUCTION: Several authors have reported evidence of loosening of the acetabular component in 14 per cent of cases at 10 years follow-up. To understand this phenomena, parametric studies of the acetabulum have involved finite element analysis, photo elastic models or strain gauges. The differing and sometimes contradictory results were due to the way the model was solicited. If the classic "Resultant" is accurate for the study of the forces on the hip, Pauwels described other forces on the pelvis during the gait. The effect of the application of these other forces on the acetabulum are the object of this study. MATERIALS AND METHOD: Four pelvises were loaded with different forces. Nine strain gauges were pasted around the acetabulum. The pelvis was loaded up to 140 Kg and a compressive force was applied to the pubis by 10 Kg increments up to 40 Kg. The stress data with and without the second force were recorded. A cortical window was bored on the anterior inferior iliac spine. Through this patch, the trabecular bone of the acetabular roof was cut up to disturb its mechanical properties. The load was once again applied to the pelvis and the stress data recorded. RESULTS: The compressive force applied to the symphyseal surface decreases the deformation of the posterior acetabular rim and increases deformation in the proximity of the ischio-iliac and iliopubic junctions. The disruption of trabecular bone generates an increase in deformation mainly perpendicularly to the acetabular rim. DISCUSSION: The decrease of the stress on the posterior acetabular rim is interpreted as a reduction of the solicitations on a fragile zone and its increase on the iliopubic and ischio iliac junctions expresses the application of the acetabular horn on the femoral head permitting better settling of the hip during the gait. The constatation of a stress increase around the acetabulum after disruption of the traecbular bone is interesting. The bone behavior with different acetabular cup models on different pelvis may be studied by strain gauges pasted on the cortical bone. The variable quality of the trabecular bone may introduce an error factor in the measurement. CONCLUSION: The deformation of the acetabulum during gait has to be studied following the different forces described by Pauwels. The compressive force on the pubic symphysis during one leg stance permits a decrease of the stress on the acetabular rim and an increase in the setting of the femoral head. Different qualities of trabecular bone change the deformation of the cortical bone for an equivalent load. This incites us, in comparative studies, to be careful in the deduction of the acetabular roof stresses from the recorded cortical bone deformations.

[Shock absorption by intermediate hip prostheses]. / Capacité d'amortissement des prothèses intermédiaires de hanche.

PURPOSE OF THE STUDY: The bipolar prosthesis was developed in an attempt to alleviate acetabular wear of conventional metallic endoprostheses. The prosthesis was designed to achieve low-friction metal-on-polyethylene inner bearing motion while decreasing shear stress across the acetabular cartilage. Although good clinical results were obtained, the principle of a persistent inner mobility was contested and some authors have assigned the delay of cartilage erosion to the shock absorption capacity of the polyethylene. The present study was focused on assessing the vibration and shock damping effect of metal monoblock and bipolar head prostheses. MATERIAL AND METHODS: The transmission of the shock wave through these two types of prostheses was studied in vitro. The two heads were first tested in a rigid environment to eliminate all external parasite frequencies. The impact excitation was applied with a hammer connected to an oscillometer. A second accelerometer was connected to the prosthesis stem. Shock wave transmission was analyzed. Secondly, the head was tested with a system vibrating in the same order of frequencies as the skeleton, with and without pre-constraint. The frequency response functions were analyzed. RESULTS: For the metallic prosthesis, the frequency of vibration recorded on the femoral stems was in a large frequency range from 0 Hz to 10 KHz. For the bipolar prosthesis, all the high frequencies of the shock wave were eliminated and only shock wave frequencies from 0 to 500 Hz were recorded. In an environmental system vibrating below 100 Hz, the metallic head did not express high frequencies of vibration. The coefficient of shock absorption was not significantly different for the two heads. DISCUSSION: In the first rigid environment, the metallic head did not filter the high frequency components of the shock wave and the bipolar head tended to eliminate high frequency components due to the flattening effect of the impulse load by the polymer. But, the lower leg is not a rigid structure and the musculo-skeletal system vibrates in frequencies below 100 Hz. In similar conditions, the increased shock-absorbing effect of the polyethylene is far more difficult to observe. For the metallic prosthesis, the recorded frequency of vibration also belongs to a small domain of frequency, from 0 Hz to 100 Hz. The range of frequency is similar for the two types of prostheses. CONCLUSION: Even though polyethylene is characterized by a more pronounced damping capacity than metallic materials, in experimental conditions simulating the vibratory characteristics of the human body, the introduction of a high-density polyethylene liner does not afford any additional shock-absorbing effect compared with a metallic head. It cannot explain cartilaginous sparing.

Geometrical analysis of the femoral neck torsion.

By the geometrical analysis of three cross sections the surface along the femoral neck, the second moments of area and the major axes of symmetry are obtained. The surface passing through these axes determined in each section, from the lateral to the medial third of the neck, is one of the two anatomical surfaces of symmetry of the neck. The geometric structure defined by this surface is a helicoid. No plane, in the ordinary sense of the word, has to be defined in the femoral neck. At the trochanteric junction, the major axis is inclined about 17 degrees on the anteversion plane, twists anteriorly and becomes more horizontal to finish with a mean inclination of 60 degrees at the cephalic junction. Surprisingly, this twist and then the neck torsion are in opposite directions to that suggested by the bony markers, often taken as a reference and reported in the anatomical descriptions.

Theoretical study of the decrease in the femoral neck anteversion during growth.

This theoretical analysis tries to explain the decrease of the femoral neck anteversion during growth according to well-established concepts. In the frontal plane, it was demonstrated that the capital epiphyseal plate inclination allows the plate to remain perpendicular to the resultant force applied to the hip during gait. In the transversal plane, the projection of this force varies from -24 degrees, outwards and forwards (heel strike), to 20 degrees, outwards and backwards (toe off). A mathematical formula calculates the instantaneous coordinates of the plate in this plane during gait. This kinematic study points out that the physiological value of the capital epiphyseal plate anteversion at the end of the growth is theoretically the ideal value to obtain in the transversal or horizontal plane a perpendicular relation between the orientation of this plate and the projection of the resultant force during walking.