Reciprocal angulation of vertebral bodies in a sagittal plane: approach to references for the evaluation of kyphosis and lordosis.

In order to establish a sagittal plane curve reference table for standing subjects examined laterally, we determined an easily reproducible standard posture. A sample of 100 healthy subjects from 20 to 29 years of age, was chosen (43 women, 57 men). The reciprocal angulations of each vertebral body in relation to the others were fed into a digitalizer and studied by computer. The study particularly concerns maximum kyphosis, maximum lordosis, sacral base slopes, and the tilt of intermediate vertebral bodies. The dispersion of the results is remarkably wide and, within the extreme values, the distribution is irregular. Individual correlations of these values are often dispersed, but spinal morphotypology. For considerable lengths, average values cannot be used as norms, given the wide span of values. Only the extreme limits are useful for the appreciation of curves as excessive, insufficient, or inverted.

[Anterior strut grafting in kyphosis and kyphoscoliosis (author's transl)]. / Greffes antérieures en étai dans le traitement des cyphoses et cyphoscolioses.

The authors have reviewed 58 cases submitted to strut grafting in the concavity of the curve. There were 44 kyphoscolioses and 12 kyphoses. The average follow-up was more than two years and the average pre-operative deformity was 127 degrees. The average improvement was 38 degrees and the secondary loss was only 3 degrees. The results are analysed with regard to the surgical technique used. In some cases, posterior fixation was added and the graft was either from the tibia, the fibula or a rib. In 16 cases a secondary fracture of the graft was found. It appeared between the fourth and tenth post-operative months. During this period, reduction of the graft was seen. The graft was found to thicken later at about the eighteenth post-operative month. It is concluded that the technique is worthwhile provided it is associated with posterior internal fixation, and that an external brace is worn for at least eighteen months after operation.

[Combination of methylmethacrylate (acrylic cement) and antibiotics. Bacteriologic and mechanical study]. / Association méthacrylate de méthyle (ciment acrylique) et antibiotiques. Etude bactériologique et mécanique.

The authors report the results of a study about the association of acrylic cement with antibiotics. Three cements have been tested: Simplex, CMW, Palacos, with 14 different antibiotics. A series of experiments has been carried out in three phases: a macroscopic study of the polymerisation of the mixture; in vitro bacteriological studies; and mechanical studies (trials of resistance to traction, flexion, shock measuring the modulus of elasticity and hardness). In vivo bacteriological testings have been carried out on 10 patients. It has come out from this study that the polymerisation of cement, usually does not destroy antibiotics which remain active and that the mechanical properties of cement are modified in sundry manners. All additions of tested antibiotics modifie mechanical properties by about 25 p. 100 but some additions seem to be preferable. Improvements must still be made and confirmed by this type of research.

[Fracture of the odontoid process (author's transl)]. / Fractures de l'apophyse odontoïde (dens) de l'axis. 102 cas dont 73 fractures récentes.

102 cases of fractures of the odontoid process have been seen by the author - 73 recent cases and 29 old ones. It was important to distinguish basal fractures (29 cases), which all united after conservative treatment by reduction and skull traction for six weeks followed by a plaster cast for six to eight weeks, and fractures of the body (44 cases). 41 body fractures were treated conservatively, of which 6 died and only 20 united. The authors consider that treatment by skull traction must always be tried. An eventual indication for surgery can be made at about the 20th day if displacement is found to be present in spite of treatment. Fusion in these cases must be limited to C1-C2. It is best obtained by a combination of wiring and grafting.

[Lumbar venography in the diagnosis of disc herniation (author's transl)]. / Apport de la phlébographie lombaire dans le diagnostic des hernies discales.

The authors have performed lumbar venography on 120 occasions in patients with low back pain. In 58 patients in whom the herniated disc was confirmed, the result of venography was positive and the localisation was precise in 67 cases. It is concluded that the method is safe, reliable and allows precision in diagnosis to allow better selection for surgical treatment. The examination is particularly useful in recurrent sciatica, fractures of the lumbar spine, recent or old, and in spinal stenosis. It may be associated with discography when the result is not clear cut.

[Stress and quantification of pressures borne by the hip in unilateral support in the sagittal plane. I]. / Etude des sollicitations et quantification des pressions subies par la hanche en appui monopodal dans le plan sagittal.

Thanks to the works of Pauwels, the pressures sustained by the hip during unilateral weightbearing in the frontal plane are now well known and have given rise to a number of surgical applications. Considered as negligible by Pauwels, the sagittal plane has been little studied; in fact, with Pauwels' methodology, but taking into account the muscular moments, it appears that the forces exerted in the sagittal plane are far from being negligible and vary, according to the phase of weightbearing, from once the weight of the body (weightbearing on the sole) to two and a half times the weight of the body (weightbearing on the heel).

[Arterial vascularization of the tibia in the adult]. / Vascularisation artérielle du tibia chez l'adulte

The arterial vascularization of the tibia in an adult is examined by microangiography (with micropaque).--The proximal epiphysis vessels originate in the periarticular circle of the knee; some are vertical, others horizontal; the condylus medialis is more vascularized than the condylus lateralis.--The metaphysis is vascularized by the arteria nutriciae terminal branches and by numerous vessels originating in the periosteal system.--The diaphysis depends on the nutrition (arteria nutriciae tibialis) and periosteal systems: these two systems are equally important in the two upper thirds but in the lower third the nutrition system is more important.--The proximal metaphysis receives numerous arteries coming from the periosteal system; they anastomose with the terminal ramifications of the arteria nutriciae.--The distal epiphysis is vascularized by three pedicles: anterior, posterior, and medial, whose branches anastomose. These pedicles are provided by the perimalleolar circle.

Biomechanics of the hip: forces exerted during walking.

Since the work of Pauwels, the forces exerted on the coxofemoral joint during walking have been studied either in different spatial planes (frontal, sagittal and horizontal) or by three-dimensional spatial analysis. Starting from the findings of our own studies, our aim was to compare the two methods of analysis (two-dimensional and three-dimensional) in order to provide a better understanding of the benefits and limitations of each method. In pursuit of this aim, we studied the pressure forces exerted on the coxofemoral joint, using a geometric plane technique following a method similar to that of Pauwels [20], and with a three-dimensional modelling technique using the finite element method. The material, taken from the published literature, was the same in both our studies. The results are expressed in terms of the size and orientation of the pressure force exerted on the coxofemoral joint during the monopodal weightbearing phase of walking. A comparison of these two methods of analysis clearly demonstrates the simplicity of two-dimensional analysis (which must incorporate as a minimum the frontal plane and the sagittal plane) and the richness of the three-dimensional analysis. The latter method, by appropriate manipulation of the information obtained, provides a starting point for computer simulations performed with the aim of testing a biomechanical or therapeutic hypothesis.

[Changes in the pressure borne by the hip during the phase of unilateral support in locomotion. II]. / Variation des pressions subies par la hanche durant la phase d'appui monopodal de la marche.

Adopting the methodology that we have just described, our study completes that of Pauwels in that we take into consideration the pressures sustained by the hip not only in the frontal plane but also in the horizontal and sagittal planes during the phase of unilateral weightbearing when walking. Thanks to the work of Braune and Fischer (1) the forces exerted on the hip are now well known and are represented by the weight of the body, the muscular forces and the dynamic forces generated by walking. From these data, we have been able to quantify the pressures sustained by the hip in each plane during the different phases of unilateral weightbearing when walking (weightbearing on heel, sole and toes).

[Comparative mechanic resistance of frozen and irradiated spongy bone]. / Résistance mécanique comparative de l'os spongieux congelé et irradié.

The mechanical properties of 20 frozen (-30 degrees C) femoral heads are determined. 10 were treated by gamma radiations. It is noted that the rate of weakness of cancellous bone is 20%.