The epidemiology of fragility fractures: Is there a role for bone quality?

Fragility fractures, particularly those of the hip, vertebrae, and distal forearm, constitute a major public health problem. The two ultimate determinants of fracture are bone strength and propensity to trauma. Bone strength depends not only upon bone mass but also upon a variety of qualitative aspects of bone structure. These include its architecture, the amount of fatigue damage it has sustained, and changes in its bulk material properties, indices that are collectively subsumed into the term bone quality Fragility fractures show differences in their patterns of incidence by age, sex, ethnic group, geographic area, and season. Many of these differences are currently unexplained, and disorders of bone quality might contribute to them. There are two fracture sites at which evidence implicates bone quality more directly—the spine and proximal femur. Many vertebral compression fractures follow minimal trauma, and controlled studies suggest that vertebral microarchitecture contributes to fracture risk independently of vertebral bone mass. At the hip, observational studies have pointed to a role for disordered trabecular architecture, accumulation of microfractures (fatigue damage), and the accumulation of osteoid. The extent to which these phenomena act independently of bone mass, however, remains uncertain.Presented at the NIA Workshop on Aging and Bone Quality, September 3–4, 1992, Bethesda, Maryland     

Risk infection factors in the total hip replacement

Infection is a complication that occurs in a considerable percentage of hip prostheses replacements, being in many cases necessary to retire them, which generates important health and economical problems. Objectives: To know the distribution of infection and its risk factors in total hip replacement. Material and methods: A four year prospective study was developed in the rehabilitation and orthopedic center of La Paz Hospital. A total of 873 patients were included. Patients were controlled by means of active epidemiological surveillance until the day of discharge, listing up their characteristics at admission and risk factors during their stay. A multivariant study was carried out to determine risk factors. Results: Patients, average age was 63 years, 3.4% of them suffered from diabetes and there were no inmunocompromised patients. The percentage of wound infection during the four years was 6%, being reduced to 1.2% in the last year. The risk factors found in the multivariant study were: incorrect prophylaxis (OR: 3.85), wrong scaring (OR: 14.06), suffering more than one intervention (OR: 7.31) and a hospitalization period longer than 30 days (OR: 2.84). Conclusion: We think that special attention in the care of the surgical wound, as well as the correct use of prophylaxis, can significantly collaborate to the reduction of infection.     

Introduction

The number of femoral fractures after hip arthroplasty has increased proportionally to the number of hip arthroplasties. Eleven university-orthopaedic centers in eastern France co-operated to review 250 femoral fractures in relation to hip prothesis. This is the largest published review. The aims of this retrospective study were:

Transient osteoporosis of the Hip: a densitometric study

Summary Three new cases of transient osteoporosis of the hip are reported. Diagnosis was achieved by plain radiographs, bone scintiscan, magnetic resonance imaging and X-ray absorptiometry of proximal femurs. The densitometry showed at the Ward's triangle a mean reduction of bone mineral density in the affected side of 36%. All subjects were treated with i.v. clodronate for ten consecutive days with a complete recovery of femoral density within 4 months. X-ray absorptiometry allows a quantification of the demineralization process and can be useful in the long term evaluation of this entity.     

Peripheral total parenteral nutrition employing a lipid emulsion (Intralipid): complications encountered in pediatric patients.

The clinical records of 180 pediatric patients who received Intralipid via peripheral veins at a single institution (1964-1977) were retrospectively analyzed, with particular reference to the complications of this form of therapy. Intralipid was used in a dose range of 2--4 g/kg/day in order to supply 40% of the daily calorie requirements. The patients were neonates, infants, children, and adolescents with a wide range of clinical diagnoses. Local complications associated with Intralipid therapy were minimal. Transient elevations in serum enzyme levels (SGOT, SGPT, and LDH) were observed in 4% of patients, but all of these returned to the normal range after cessation of therapy. Ten patients had histologic evidence of cholestasis, the significance of which is discussed. The lipid emulsion was employed in patients with preexisting hyperbilirubinemia with concomitant resolution of jaundice. Intralipid was administered to patients with known severe thrombocytopenia (secondary to sepsis or myelosuppression) with return of the platelet counts to normal levels during the course of infusion therapy. The use of Intralipid in patients with established sepsis did not delay its response to conventional surgical or antibiotic therapy. There were no instances of the "overloading" syndrome observed.     

Four and a half years experience with a vertical flow sterile enclosure

Summary During the use of a vertical flow enclosure of our own design for almost five years, bacteriological studies and the infection rates in different groups of patients have taught us the following:1. In a clean room operating theatre, the use of a respired air exhaust system improves the sterility compared with the use of ordinary masks. In a vertical flow enclosure, the chest, the arms, and the hands of the team are contaminated from respired airborne bacteria if helmets, etc., are not worn.2. In our vertical flow enclosure with almost continuous absolute sterility of the air, the infection rate in primary total hip replacement is very low and less than 1%, including early and late infections. Antibiotics have not been used.In secondary surgery, i.e., total hip replacement in hip joints previously operated upon, the infection rate is markedly higher, probably because of a flare-up of latent infection.Clean room surgery therefore, can only prevent air borne contamination, and no more; but this is very valuable.3. Vertical flow enclosures of the Charnley-Howorth (1975) and Weber et al. (1971) type provide considerable improvement in sterility of the air compared with adaptations of more conventional theatres. We recommend that these facilities be made available for implant surgery. It is also necessary to have a stringent operational policy with cooperation and discipline on the part of all members of the theatre team.

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Résumé Durant l'utilisation, depuis plus de 5 ans, de la serre stérile à flux laminaire vertical que nous avons construite, nous avons pratiqué des études bactériologiques et pu comparer les taux d'infection suivant les groupes de patients.1. Dans une salle d'opération propre, la stérilité est considérablement améliorée par le port de casques possédant un système d'aspiration de l'air expiré, ceci par rapport au port de masques ordinaires. De plus, si l'on ne porte pas le casque dans une serre à flux laminaire vertical, le tronc, les mains et les membres supérieurs de l'équipe chirurgicale sont contaminés par les microbes en suspension dans l'air expiré.2. Dans notre serre où l'air est pratiquement stérile, le taux d'infections précoces et tardives est inférieur à 1% dans les arthroplasties de la hanche, et cela sans utilisation d'antibiotiques.Lors d'interventions dites secondaires, c'est-à-dire dans les cas déjà opérés au préalable, par exemple par ostéotomie, ostéosynthèse, etc., le taux d'infection est plus élevé. On doit probablement en rechercher la cause dans une contamination de la plaie lors de la première intervention, l'infection alors à l'état latent pouvant se réveiller à la faveur d'une nouvelle opération.En opérant dans une serre stérile, on peut donc prévenir la contamination par l'air ambiant, mais pas plus. Cela est cependant déjà très appréciable.3. Comparées aux salles d'opération conventionnelles modernes, les serres stériles à flux laminaire vertical, comme celle de Charnley-Howorth (1975) et Weber-Meierhans (1971), améliorent considérablement la stérilité de l'air. Surtout pour la chirurgie prothétique de la hanche, dont les risques d'infection sont élevés, nous recommandons l'emploi de ce genre d'installation. Mais il est nécessaire que tous les membres de l'équipe chirurgicale adoptent des règles très strictes de discipline.

     

Three-dimensional imaging of mitral and tricuspid annuli for total artificial heart implantation

The establishment of a method to clarify the three-dimensional interrelations among the mitral annulus, tricuspid annulus, ascending aorta, and main pulmonary artery, which constitute the interface between the human and total artificial heart (TAH), is essential to the design of the TAH. In a previous study based on transverse magnetic resonance (MR) images of a live human heart, reconstructed images of mitral and tricuspid annuli were found to be deformed. The present study of cadaver and beating hearts revealed that the optimal conditions for atrioventricular annular reconstruction of a beating heart with electrocardiogram-gated MR imaging include use of four-chamber imaging, 5 mm slice thickness, and a slice interval ranging from 5 to 7 mm. Under these conditions, the mitral and tricuspid annuli of 3 beating hearts were reconstructed successfully. It was recognized that during the systolic phase the mitral and tricuspid annuli move anteriorly, leftward and downward, and that in late systole the right lateral margin of the tricuspid annulus is close to the sternum.     

Forces and moments on the human leg in the frontal plane during static bipedal stance.

An experimental apparatus was assembled that permitted measurement of the vertical and lateral ground reaction forces as the hip is abducted, resulting in foot separations ranging from 0.25 to 71 cm, with the knee in 0 degree flexion. Twelve healthy volunteers (8 men and 4 women) were tested. The hip joint was located by means of center of rotation measurements on each subject's legs, and the location of the knee joint was determined using anatomical measurements. It was observed that the mediolateral force was nonzero and directed toward the body midline, even when the subject's feet were placed together. With the feet placed at shoulder width, the population mean mediolateral force was 3% of body weight. It was determined that simplifying assumptions based upon either "zero lateral force," or "zero hip moment," produced errors, when compared with our measured values, over various ranges of foot separation, with the zero hip moment assumption providing accuracy over a broader range. The inclination of the tibial plateau, with respect to the long axis of the tibia, that would produce minimal mediolateral shear at the knee is presented. Research and clinical applications of our results and techniques are discussed.     

Stoffwechseluntersuchungen unter ergometrischer Belastung bei total duodenopankreatektomierten Patienten

Zusammenfassung Ein Jahr nach totaler Duodenopankmatektomie wurde bei 6 Patienten die exokrine Pankreainsuffizienz geprüft. Diese kann durch orale Gabe von wenigstens 10 g Pankreatin kompensiert werden. Gegenüber 7 Normalpersonen und 6 Typ 1-Diabetikern hatten die Duodenopankreatektomierten unter körperlicher Belastung höhere arterielle Spiegel von Lactat und freiem Glycerin als Ausdruck einer gestörten hepatischen Gluconeogenese bei fehlendem pankreatischem Glucagon. Ihre körperliche Leistungsfähigkeit war auffallend schlecht. Catecholamine stiegen unter körperlicher Belastung nur gering an, Wachstumshormone gar nicht. Diese Resultate sprechen gegen die totale Duodenopankreatektomie als Therapie der chronischen Pankreatitis.

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Metabolic investigations under ergometric strain in patients with total duodenopancreatectomy

Summary One year after total duodenopancreatectomy a clinical and laboratory evaluation including exhaustive bicycle ergometry was performed in 6 male patients. The insufficiency of the exocrine pancreas can be compensated by at least 10 g pankreatin per day. During physical exercise patients had higher arterial values of lactate and free glycerol after duodenopancreatectomy than 7 healthy individuals and 6 diabetic patients type 1. This metabolic overreaction was due to a deficiency of pancreatic glucagon and resulted in an impaired hepatic gluconeogenesis. There was no detectable increase in growth hormones and only a small one in catecholamines. The physical condition of patients after duodenopancreatectomy was clearly worse.

Diese Arbeit ist Herrn Prof. Dr. Dr. h.c. Hans Erhard Bock zum Geburtstag gewidmet