[Unstable pelvic ring fracture: osteosynthesis of the posterior lesion by percutaneous sacroiliac fixation]. / Fractures instables de l'anneau pelvien: ostéosynthèse de la lésion postérieure par vissage sacro-iliaque percutané

PURPOSE OF THE STUDY: We report our experience with percutaneous sacroiliac screwing for unstable pelvic ring fracture. MATERIAL AND METHODS: Twenty unstable pelvic ring fractures with sacroiliac disjunction (9 cases), trans-sacral fracture (9 cases), or bilateral posterior fractures (5 cases) were managed with percutaneous sacroiliac fixation using 1 or 2 screws. There was also pubic disjunction in 7 cases, managed by osteosynthesis in 5 cases. No fixation of fractures of one or both of the obturator rings, present in 13 cases, was attempted. The posterior screwing was performed under fluoroscopic guidance in 15 cases and computed tomographic guidance in 5. RESULTS: There were no infectious or neurological complications. Radiographically, anatomic reduction of the posterior fracture was achieved in 10 cases. A vertical ascension persisted in 4 patients and a rotation in 6. Radiographic results were correlated with delay to surgery: correction of the vertical displacement was achieved in 80% of the patients operated before five days and in 55% of the others. Two patients experienced a secondary displacement. There was no cases of nonunion of either the anterior or posterior fracture. Follow-up was available for 14 patients (2 patients died and follow-up was too short for 4). The mean Majeed score was 92/100 and none of the patients experienced anterior pain. Three patients had moderate pain in the sacroiliac area. DISCUSSION: The ventral position appears to be best adapted for percutaneous sacroiliac screwing but can be contraindicated by concomitant lesions. We prefer fluoroscopic guidance for these emergency procedures. Two views, ascending and descending, appear sufficient. The better stability provided by two screws can be achieved under computed tomographic guidance without risk of neurovascular damage. CONCLUSION: Percutaneous sacroiliac screwing is a good management strategy for unstable pelvic ring fractures with little risk of morbidity.

Analysis of retrieved polymer fiber based replacements for the ACL.

The present retrospective analysis of 117 surgically excised anterior cruciate ligament (ACL) prostheses was designed to elucidate the etiology and mechanisms of failure of synthetic ligamentous prostheses. They were harvested from young and active patients (26 +/- 7 yrs) at various orthopaedic centers in France between 1983 and 1993. The average duration of implantation of augmentation and replacement prostheses were 21.5 +/- 12.6 and 33.2 +/- 25.3 months, respectively. The principal causes for their excision were ruptures and synovitis. Each ACL prosthesis was examined macroscopically, histologically, and, after tissue removal, by scanning electron microscopy (SEM) to determine the model, manufacturer, surgical technique used at implantation, the extent of healing, the site of rupture, and the morphology of the damaged fibers. Fourteen types of ACL prostheses were analysed, each fabricated using a different combination of polymers, fibers and textile constructions. Consequently, they generated a variety of healing characteristics and mechanical responses in vivo. SEM observations revealed that abrasion of the textile fibers as a result of yarn-on-yarn and/or yarn-on-bone contact was a common phenomenon to almost all models, and was the primary cause of prosthetic failure. Healing inside the synthetic ACL was poorly organized, incomplete and unpredictable as the extent of collagenous infiltration into the textile structure did not increase with the duration of implantation. In fact, the collagenous infiltration into certain models appeared to be more detrimental than beneficial since it caused deterioration and fraying of the textile structure rather than serving as a reinforcing matrix around the prosthesis. In conclusion, the present study shows that three mechanisms may be involved in the failure of ACL prostheses: (1) inadequate fiber abrasion resistance against osseous surfaces; (2) flexural and rotational fatigue of the fibers, and (3) loss of integrity of the textile structure due to unpredictable tissue infiltration during healing.

[An unusual anomaly : cervical spondylolysis in an adult]. / Une anomalie exceptionnelle: la spondylolyse cervicale chez l'adulte.

A case of spondylolysis with exceptional involvement of the cervical spine is reported. The lesion turned out to be a defect in the pars interarticularis of a cervical vertebra. Such cases generally involve the sixth vertebra. Spondylolysis is asymptomatic more often than not. Positive diagnosis is supported by an analysis of the anatomic structures on radiographs and CT-scans. Differential diagnoses include congenital lesion (articular dysplasia) is always found, there is no argument allowing the assertion that cervical spondylolysis is a congenital condition rather than secondary to stress fractures.

[Total hip arthroplasty. Risk factors and prevention of iatrogenic vascular complications]. / Arthroplasties totales de hanche. Facteurs de risque et prévention descomplications vasculaires iatrogènes.

Vascular injuries during orthopaedic hip surgery are rare. However, they must always be feared because they threaten life and limb. We present 11 vascular injuries observed over a 12-year period. Seven women and 4 men, treated by elective surgery, presented 14 vascular injuries (6 arterial, 5 venous and 3 prosthetic vascular graft). Four injuries occurred during revision procedures. They were all operated as an emergency for ischaemic syndrome (6 cases) and/or haemorrhage (7 cases). Four patients (37%) died and 4 developed sequelae, various directly attributable to the vascular injury. In the light of these cases, we tried to determine the various mechanisms of the injury and the orthopedic and vascular risk factors. Preoperative detection and well defined therapeutic rules are very important for the prevention of these severe vascular accidents.

Quantitative measurement of joint space narrowing progression in hip osteoarthritis: a longitudinal retrospective study of patients treated by total hip arthroplasty.

OBJECTIVES: To evaluate the rate of progression of radiological joint space narrowing (JSN) in patients operated on for hip osteoarthritis (OA) and to determine its predictive factors. STUDY DESIGN: retrospective longitudinal trial of 61 patients who underwent total hip arthroplasty (THA) for hip OA (69 operated hips). Mean follow-up 81.2 +/- 9.9 months. Collected data: (1) standing frontal radiographs of the pelvis from diagnosis to surgery (246 films) for morphological evaluation and quantitative measurement of joint space width (JSW) (computerized reading of digitized X-rays); (2) demographic data (sex, age, body mass index, smoking status, professional and sporting activities, family history of OA); (3) clinical data (age at onset-diagnosis and THA, drug consumption, time from diagnosis to permanent disability, OA at other joints, previous THA of the contralateral hip). STATISTICS: multivariate analysis. RESULTS: The yearly mean narrowing (YMN) of MeanJSW was 0.43 +/- 0.43 mm/yr (median 0.29, range 0.03-2.55). YMN correlated inversely with joint space width at operation and follow-up duration, and was increased in atrophic OA (r = 0.71). The time between diagnosis and THA correlated with JSW at diagnosis, and was inversely correlated with age at onset and YMN. It was longer in patients with hypertrophic OA (r = 0.69). CONCLUSION: Rapid progression of JSN, older age and absence of osteophytes appear to be the main factors leading to THA.

Acetabular anatomy and the relationship with pelvic vascular structures. Implications in hip surgery.

Most direct vascular trauma occurring during hip surgery results from injury to pelvic vascular structures which are not visible during the procedures of reaming, drilling holes or the fixation of screws. In this study, 5 pelves of fresh cadavers were injected with a radiopaque mixture and were visualised with a scanner according to 5 predetermined sections. Bone depth of the acetabulum was measured in each section. A calculation was made describing the minimal distance separating the inner cortex from the principal pelvic vessels. After an anatomic dissection of each pelvis, the relationship between the vessels and screws of the fixation cup, implanted identically on the quadranted acetabulum, was observed. The screws placed in the anterior and inferior quadrants and the center of the acetabulum endangered the external iliac v. and a. and the obturator pedicle. The depth of the periacetabular bone was greater in the superior and posterior quadrants. The inferior gluteal, pudendal and superior gluteal aa. were more than ten mm from the posterior wall. Conversely, the external iliac and obturator pedicles came in contact with the osseous surface on which they lay. A projection of the vessels on the acetabulum was made, and the reproducible character of the acetabular-quadrant system was verified. The superior quadrant offers all the characteristics of a vascular safe zone. A knowledge of these anatomic relationships explain vascular trauma in pelvic fractures and helps to prevent vascular injury in hip surgery.

[Evaluation of the predictive value of fibrin degradation products in the detection of deep venous thrombosis after total knee prosthesis]. / Evaluation de l'intérêt prédictif des produits de dégradation de la fibrine (PDFb) en ELISA dans le dépistage des thromboses veineuses profondes après prothèse totale du genou.

The total knee arthroplasty (TKA) favours deep venous thrombosis (DVT), more often sural thrombosis. In this case, pulmonary embolism is exceptional but sural thrombosis can give a poor functional prognostic by trophic disorders. The purpose of this work is to verify the predictive value of D-Dimer by Elisa technic in the detection of DVT after TKA. We have studied 42 TKA at the Edouard HERRIOT Hospital(Lyon) between April 2, 1992 and October 20, 1994. Patients were divided in two groups: with DVT (n = 5) and without DVT (n = 37). Prophylactic heparinotherapy was systematic. The biologic follow-up by ELISA technic(Fibrinostika FbDP, Organon Teknika) of the D-Dimer were realized at D0 (Day 0) preoperative period and D1, D4, and D6 postoperative period. An echo-Doppler exam were effected at D8 postoperative. The analysis of mean rate of the D-Dimer didn't show significative difference between the two groups at D0, D1, D4 and D6. But, we observed that the rate of D-Dimer increased after TKA significantly in both groups. We can't evaluate predictive interest of the D-Dimer after TKA but the little number of DVT authorizes to pursue this study and to moderate our conclusion.

Anatomical basis for the choice of the femoral implant in the total hip arthroplasty.

There is within the population a considerable variation in the endosteal canal anatomy of the proximal extremity of the femur. This anatomical variation might jeopardize the result of the total hip arthroplasty when the surgeon uses a cementless femoral shaft. Indeed, if the secondary fixation of an implant stays under the dependency of many parameters, one has to obtain before anything else a very good primary stability, obtained by the morphological appropriateness of the bone-implant. The authors propose to define the cementless indications, as regards total hip arthroplasty, defining two radio-anatomical parameters: the Cortico-Medullary Index and the Femoral Flare Index.

Morphometry of the talocrural joint.

Based on two orthogonal radiologic views, the authors present a morphometric study of the talocrural joint. In 50 normal subjects, 10 parameters were measured and divided into 3 groups: the distal tibial joint surface parameters, the malleolar parameters and the talar parameters. These parameters were treated in both a descriptive and a correlative analysis. If the talocrural joint is a hinge joint whose talar articular surface can be simplified and classed as a cylinder segment, it is possible to calculate its curve radius. Then the correlative analysis allows to define the talar parameters and the corresponding parameters of the distal tibial joint surface. The malleolar parameters are independent factors. This study is the first morphologic analysis to serve as a basis for an ankle arthroplasty.

[Total hip arthroplasty - The choice of the femoral component: cemented or uncemented?] / Arthroplastie totale de hanche avant 50 ans ­ Choisir l'implant fémoral: Avec ou sans ciment? standard ou "sur mesure"?

The shape of the femoral canal is variable, much more variable than most contemporary designs of femoral components would suggest or can accomodate. Several studies have demonstrated the clinical importance of a close match between the dimensions of the femur and the implanted prosthesis. The clinical significance ofbone implant proximal fit has been noted for cementless mode fixation. A practical consequence of the variability of the proximal endosteal canal is that different femoral components may be needed for all the patients of the population. For the autors, the choice of the technique (cement or cementless), and the choice of the optimal femoral stem (standard or custom-made implant) depends on two radiologic parameters: I.C.M. and I.E.F.; these parameters are defined and analysed.

[Preliminary and multidisciplinary study of three Coptic mummies of the Testut-Latarjet museum at Lyon]. / Etude pluridisciplinaire et préliminaire de trois momies coptes du Musée Testut-Latarjet de Lyon.

In 1901 Albert Gayet raked up from Antinoe three mummies exhibited to day at the Anatomy Museum of Lyon. The study of the three mummies was made in detail as to their dress, anthropometric and scannographic findings. The clothes were characteristic of coptic civilization. The radiographic date gave a life span of around 40 years. The X-ray imagery shows the remains of cerebral and visceral organs. The sexual criteria are thought to be those of two women and undetermined for the child. Later, several investigations like endoscopic autopsy, tooth microscopy and chromosomic map will be necessary.

The upper end of the femur: dimensions of the endosteal canal.

Based on a prospective study of 30 right or left femurs removed in a continuous series in the anatomy department, a study was made of the dimensions of the endosteal canal of the upper end of the femur. The femora were analysed by means of 12 CT scans below the lesser trochanter. The sections were numbered and the dimensional parameters calculated by computer, using an original plan. The results were subjected to descriptive and correlative analysis. From these dimensional findings it appeared that the anatomy of the upper end of the femur is not random; morphotypic models exist and the laws of a normal model are regulated by a mathematical equation.

[Post-operative fractures: epidemiology, predisposing factors]. / Fractures à distance de l'arthroplastie : épidémiologie, facteurs favorisants.

The general predisposing factors are female sex and osteoporosis. The local predisposing factor is loosening of the stem.As expected type III fractures are more frequent in case of osteoporosis (notion of elasticity gap) and fractures type II and I in case of loosening (notion of bone stock).

Detection and measurement of vitamins K1 and K2 in human cortical and trabecular bone.

Vitamin K plays an essential role in the gamma carboxylation of the gla-containing proteins of bone matrix, such as osteocalcin. We have measured the concentration of vitamin K1 (VK) and of the menaquinones MK-6, MK-7, and MK-8, the three major vitamin K2 moieties, in trabecular and cortical bone taken from the femoral neck of patients undergoing hip replacement. Both bone compartments were found to contain large amounts of VK, MK-6, MK-7, and MK-8. Concentrations were as high as those reported for the liver, the major storage organ for vitamin K. Further research is required to examine the association between vitamin K in bone and the gamma carboxylation of vitamin K-dependent bone proteins.

[Sandblaster or alumina-coated 316 L stainless steel for implantable material in orthopedic surgery. Study on metacarpal bone of sheep]. / Matériaux implantables en chirurgie orthopédique en acier 316 L inoxydable traité par sablage ou revêtu d'alumine. Etude sur l'os métacarpien de mouton.

We have carried out a study in sheep of the behavior of bone in the presence of two materials, 316 L stainless steel with a surface roughened by sandblasting, and the same type of steel, plasma-coated with alumina. Twelve nails of each type were implanted into the medullary cavities of previously fractured metacarpal bones. The samples were removed after 90 days for six animals and after 180 days for six others. The functional study and the radiographic analysis, as well as the growth of bone around the implants as assessed with a light microscope and with microradiography, did not show any significant difference between both types of temporary implants.

Study of an inhibitor of plasminogen activator (tranexamic acid) in the treatment of experimental osteoarthritis.

The effects of tranexamic acid, an inhibitor of plasminogen activator, were evaluated in a rabbit model of osteoarthritis induced by section of the knee joint anterior cruciate ligament. Prophylactic treatment administered intramuscularly thrice weekly for 12 or 24 weeks significantly reduced cartilage destructive lesions, increased cartilage hypertrophy but did not prevent changes in cartilage water and proteoglycan content. A suppression of synovial membrane stromelysin and collagenase activity was found while phospholipase A2 activity was unaffected.