Intermittent palpebral oedema following surgery for nasofrontal encephalocele.

PURPOSE: To report a case of intermittent palpebral oedema secondary to a cerebrospinal fluid (CSF) leakage, following encephalocele surgery. CLINICAL CASE: A 9-year-old girl consulted with a history of intermittent swelling of the left upper and lower eyelid. The symptoms started at the age of one. As a relevant fact in her medical history, a neurosurgical repair of a nasofrontal encephalocele at the age of 9 months was withheld. Elaborate imaging studies demonstrated a leakage of cerebrospinal fluid (CSF) into the preseptal periorbital soft tissues, originating from a bony defect in the medial orbital wall. The patient was treated conservatively. CONCLUSION: A CSF leakage in the orbital or periorbital region is a rare finding. In the literature, similar defects have been reported after trauma or associated with neoplasia. To our knowledge, this is the first case of periorbital CSF leakage after encephalocele-surgery reported in the literature.

Histological examination of drill sites in bovine rib bone after grinding in vitro with eight different devices.

The way in which bone is processed may affect the quality of the specimen and how much information may be gleaned on histological examination. We investigated eight widely used rasps and drills and compared the results. All large chip cutters damaged the bed and marrow of the bone. The tool that caused the least damage was the wet grinding diamond tool.

Severe visual impairment and retinal changes in a boy with a deletion of the gene for Nance-Horan syndrome.

We present the ophthalmologic findings in a boy with a deletion of Xp22 comprising the gene for Nance-Horan syndrome. Different mechanisms underlying the visual impairment in Nance-Horan syndrome are discussed.

Cementless isoelastic RM total hip prosthesis.

Some surgeons are beginning to doubt the reliability of bone cement in joint replacements. In 1967 Robert Mathys conceived the idea of an isoelastic prosthesis made of plastic, which would anchor into the bone without cement. He developed the idea by extensive tests in animals and, in 1973, the first human RM cementless hip prosthesis was inserted by E Morscher. In this paper the concept of the cementless isoelastic prosthesis is developed by Robery Mathys, and Professor Bombelli records his experience with the prosthesis between 1977 and 1981.

[Snowboarding accidents]. / Snowboard-Unfälle.

The present review summarises the related literature of the last ten years with request to snowboarding accidents. Sport accident statistics of snowboarding show high and increasing numbers of injuries. Already snowboarding ranks third of all sport accidents in Switzerland. According to the literature the injury risk in snowboarding is twice that of skiing, although the injuries are less serious. About 50% of the injured snowboarders are beginners. Beginners have a higher risk of injury than more advanced snowboarders. Additionally, and a relative large part of them are injured the first day of their snowboard career. The pattern of injury has changed over the last years. Today, injuries to the lower extremities account no longer for more than 50% but are now decreased to about 25%. Nowadays, wrist, knee, ankle, and shoulder are the most frequently injured body parts. It is the authors opinion that with up-to-date protectors, release bindings, and training of falling techniques the numbers and seriousness of injuries could be reduced, in particular injuries to the wrist and ankle.

Simulation of the effects of different pilot helmets on neck loading during air combat.

New generation pilot helmets with mounted devices enhance the capabilities of pilots substantially. However, the additional equipment increases the helmet weight and shifts its center of mass forward. Two helmets with different mass properties were modeled to simulate their effects on the pilot's neck. A musculoskeletal computer model was used, with the methods of inverse dynamics and static optimization, to compute the muscle activations and joint reaction forces for a given range of quasi-static postures at various accelerations experienced during air combat. Head postures which induce much higher loads on the cervical spine than encountered in a neutral position could be identified. The increased weight and the forward shift of the center of mass of a new generation helmet lead to higher muscle activations and higher joint reaction loads over a wide range of head and neck movements. The muscle activations required to balance the head and neck in extreme postures increased the compressive force at the T1-C7 level substantially, while in a neutral posture the muscle activations remained low. The lateral neck muscles can reach activations of 100% and cause compressive joint forces up to 1100N during extensive rotations and extensions at high 'vertical' accelerations (Gz). The calculated values have to be interpreted with care as the model has not been validated. Nevertheless, this systematic analysis could separate the effects of head posture, acceleration and helmet mass on neck loading. More reliable data about mass properties and muscle morphometry with a more detailed motion analysis would help to refine the existing model.

[Athletic accidents and resulting injuries]. / Sportunfälle und Verletzungsfolgen.

Some 245,000 sporting accidents occur yearly in Switzerland. The social accident costs amount to approximately 1.8 billion francs per year. Every second sporting accident occurs during a ball game. For the shown sporting activities, distortion is the most common type of injury among adults and contained fractures are most common in children. As is to be expected, the number of accidents has grown along with the exploding popularity of snowboarding and in-line skating. These new sporting activities show no unknown injury patterns which would demand new treatment methods.

Special instruments and prosthetic cups for the removal and replacement of a total hip prosthesis.

In the course of replacing more than 500 total hip prostheses over a period of five years the authors have developed a new set of instruments for the removal of the defective prosthesis and cement and for improved anchorage of the new prosthetic cup. The set comprises: 1. A set of special chisels and an axially guided drill for removal of the old cement from the femur. These instruments greatly simplify the latter procedure. 2. A new type of prosthetic cup with a weight-bearing collar. This cup is used for cases in which the amount or structure of the acetabular bone is such that it will not support a conventional cup. 3. A new type of drill with a flexible drive and easily exchangeable drill bits for cutting anchorage holes in otherwise inaccessible parts of the acetabular bone.

The treatment of femoral neck fractures with an isoelastic endoprosthesis implanted without bone cement.

We report about our first experiences inserting an "isoelastic" femoral endoprosthesis in cases of a fractured femoral neck. 28 patients have been observed for a period of more than 1 year after surgery. We did not find loosening or incompatibility of the polyacetal-resin material. We believe the implantation of this prosthesis type without cement fixation is especially advantageous. The histologic result of a patient who died 6 weeks after surgery did not reveal any tissue incompatibility. We observed an excellent fixation of the prosthesis by bone growth into the surface indentations of the stem.

[Initial clinical experience with osteosynthesis of femoral shaft fractures with a newly developed intramedullary implant (claw interlocking nail)]. / Erste klinische Erfahrungen mit der Osteosynthese von Oberschenkelschaftfrakturen mit einem neuentwickelten intramedullären Implantat (Krallenverriegelungsnagel).

The implantation of distal interlocking screws in interlocking nailing can be difficult and time-consuming. With the AO Universal Femoral Nail as the basis, an implant was designed with which distal interlocking is accomplished from the inside of the nail by means of a simple claw mechanism. Instrumentation and interlocking are possible from the proximal standard approach, so that an additional operation adjacent to the knee (which is necessary when interlocking bolts are used) is superfluous; neither for the insertion nor for the removal of the interlocking mechanism is an image intensifier necessary. We stabilized 24 femoral shaft fractures with this new interlocking nailing device [20 fresh fractures, 3 refractures and 1 pathologic fracture caused by tumor metastasis from chronic myeloid leukemia (CML)]. The mean age of the patients concerned was 34.8 years (18-57 years). Fractures were classified according to the Müller classification with 11 type-A fractures (45.8%), 9 type-B fractures (37.5%) and 4 type-C fractures (16.7%). There were only 2 cases (8.3%) with open fractures. In 11 cases (45.8%) the fracture was located in the midshaft region, in 6 cases (25.0%) in the proximal shaft, and in 7 cases (29.2%) in the distal femoral shaft. Multiple trauma was present in 11 patients (45.8%), while in 8 patients (33.2%) the femoral shaft fracture was the only major injury. Full weight-bearing was allowed after a mean of 4.4 weeks (0.7-8.2 weeks). In 1 case we saw a deep venous thrombosis with pulmonary embolism obvious on clinical examination and scintigraphy. Two patients died of their multiple trauma, and of cachexia the patient with the CML metastasis died 6 weeks after stabilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Developments toward large-scale bacterial bioprocesses in the presence of bulk amounts of organic solvents.

Many pseudomonads and other bacteria can grow on aliphatic and aromatic hydrocarbons that occur in the environment. We are examining the potential of such organisms as biocatalysts for the oxidation of a variety of substituted aliphatic and aromatic compounds. To attain a high production rate of oxidation products via such biotransformations, we have focused on two-liquid phase culture systems. In these systems, cells are grown in liquid media consisting of an aqueous phase containing water-soluble growth substrates and droplets of a water-immicible organic solvent containing bioconversion substrates and products. For industrial applications of such two-liquid phase processes, several questions remain. What are the maximum rates at which apolar compounds can be transferred from the apolar phase to cells growing in the aqueous phase, i.e., what are the maximum space-time yields attainable in two-liquid phase fermentations under practical conditions? What does an efficient downstream processing of two-liquid phase medium involve? What safety regimes should be considered in working with flammable organic solvents? Can elevated pressure be used to increase oxygen transfer? Based on answers to these questions, we have recently developed a high-pressure, explosion-proof bioreactor system with Bioengineering AG (Wald, Switzerland), which will be installed in our pilot plant and used to explore two-liquid phase bioconversions at a pilot scale.

A locking hook spinal rod system for stabilization of fracture-dislocations and correction of deformities of the dorsolumbar spine. A biomechanic evaluation.

Existing internal fixation systems for the injured or deformed spine present problems with overdistraction and control of the contoured rod necessary for transverse forces. A locking hook spinal rod avoids these problems by using a locking cover to secure the lamina in the hook and meshing radial grooves to lock the contoured rod to both the upper and lower hooks in 6 degrees intervals of rotation. The 7-mm stainless-steel rod is 50% stronger than the 1/4-in Harrington rod and also avoids the weakening effect of the notches. Cadaver spine testing gives nearly a threefold increase in failure strength (125 +/- 17 Nm versus 44.1 +/- 2.1).

[A method of quantitative determination of tissue tolerance in decreased relative movement between implant and tissue]. / Methode zur quantitativen Auswertung der Gewebsverträglichkeit bei verminderter Relativbewegung zwischen Implantat und Gewebe.

A method of testing in vivo tissue tolerance to different implant materials is presented. It aims at reduction of variance due to mechanical irritation at the tissue-implant interface through the use of cylindrical implants with grooves. The special type of histological preparation which is necessary and problems encountered when using these techniques are described. The numerical evaluation of round cells and foreign body giant cells seems to give uniform results with low variance, which could be of interest for standard testing of material.

A locking hook-spinal rod: current status of development.

A locking hook spinal rod previously demonstrated to be sufficiently stable and strong in cadaver experiments has been employed in 30 unstable thoraco-lumbar spinal injuries with results superior to Harrington instrumentation.