[An empirical analysis of patients' preference of setting for outpatient arthroscopic surgery]. / Ambulantes Operieren: Praxis oder Krankenhaus? Eine empirische Analyse von Bevölkerungspräferenzen für die Wahl des Behandlungssettings.

BACKGROUND: The aim of this study was to investigate patient preferences of setting for outpatient surgery--office-based, hospital-based, or inpatient care environment--and the factors relevant to their decision. METHODS: Preferences were elicited from a sample of the general population (n=1,134) with a discrete choice model, an efficient technique for estimating utility. Participants chose their preferred mode among different outpatient scenarios for hypothetical arthroscopic surgery. RESULTS: The subjects were open to alternative options of care delivery and based their decisions on particular attributes, "specialization," "staff continuity," and "waiting time" having the largest effect on choices. A slight preference for hospital-based outpatient surgery was observed. CONCLUSIONS: The results show that patients' choice of providers is open and based on specific attributes of treatment delivery and institution and not the setting per se.

Distribution of sensory receptors in joints of the upper cervical column in the laboratory marsupial monodelphis domestica.

In order to investigate the sensory innervation, the upper cervical spine of a small laboratory marsupial (monodelphis domestica) was examined with serial section light microscopy and re-embedding of selected sections for electron microscopy. Large numbers of free nerve endings supplied by A delta- and C-fibres were found in the longitudinal ligaments and facet joint capsules. Electron microscopically, areas of direct contact between axon and collagen fibres of the surrounding connective tissue separated only by the basal lamina were observed. Such structural adaptations suggest mechanoreceptive or polymodal nociceptive functions. In addition, about 100 small lamellated corpuscles were found in the longitudinal ligaments mainly concentrated around the first intervertebral disk. Electron microscopy shows finger-like processes extending from the axon terminal into the inner core lamellae. These are the likely sites of the mechanoelectric transduction process. Smaller numbers of lamellated corpuscles were seen in the lower intervertebral disks and facet joint capsules. Lamellated corpuscles are known to function as rapidly adapting mechanoreceptors supplementing information supplied by muscle spindles to the CNS about position and movement of the cervical spine.

Topography of mechanoreceptors in the shoulder joint region--a computer-aided 3D reconstruction in the laboratory mouse.

BACKGROUND: We investigated the pattern of distribution of corpuscular sensory nerve endings in the shoulder region of the laboratory mouse in relation to their functional properties. METHODS: Twelve adult female white NMRI-F2-mice were used. The topography of sensory nerve endings in the shoulder joint region was reconstructed by three-dimensional image processing by using serial silver-stained sections of paraffin-embedded samples. Semithin sections obtained from additional samples were used for light microscopy. RESULTS: Within the fibrous layer of the joint capsule, three types of mechanoreceptors were identified: small lamellated corpuscles of the Pacini type, Ruffini corpuscles, and Golgi tendon organs. Intracapsular small lamellated corpuscles of the Pacini type (in an average number of 29/joint) were found mainly in three areas: in the predominantly flaccid tissue of the axillary region, in the denser ventromedial parts of the capsule, close to the scapula, and in the tight texture of the fiber bundles near the glenoid labrum. Ruffini corpuscles were identified only in small numbers (2/joint) in the ventral aspect of the articular capsule of two animals. Golgi tendon organs (14 or 15 receptors/joint) were discovered predominantly in close vicinity to the joint capsule at the muscle tendon junction of the inserting rotator cuff muscles and in the biceps brachii and triceps brachii muscles. CONCLUSIONS: In view of their location in the shoulder joint capsule and the glenoid labrum, corpuscular mechanoreceptors evidently play an important role in joint control by inducing protective reflex actions in phases of extreme or abnormal movement. The density of sensory receptors in distinct areas of the shoulder joint capsule appears to be related to zones that are subjected to increased biomechanical stress during physical activity.

The sensory innervation of the shoulder joint of the mouse.

The ultrastructure and location of sensory nerve endings in the shoulder-joint capsule, its tendinous reinforcements and in the periarticular connective and muscle tissue have been studied by means of light and electron microscopy in adult female white NMRI-F2 laboratory mice, aged 2.5-13 months. Most of the sensory nerve endings were detected in the fibrous layer of the joint capsule or in the inserting tendons. The identified lamellated corpuscles of the Pacini type are small and sometimes associated with Golgi tendon-organs. Large Vater-Pacini corpuscles were not detected. Ruffini corpuscles are found in small numbers only in the moderately dense connective tissue of the joint capsule. Golgi tendon organs were found mainly at the muscle-tendon junction of the muscles surrounding the joint. Muscle spindles have been identified mainly in periarticular muscles close to the muscle-tendon junctions. The number and distribution of the different types of mechanoreceptors investigated in the present study suggest that periarticular corpuscular sensory nerve endings play an important role in shoulder-joint control and mobility. The occurrence of small uniformly shaped lamellated corpuscles of the Pacini type in qualitatively different areas of surrounding tissue implies that they are susceptible to different kinds of mechanical stimuli.

Functional topography and ultrastructure of periarticular mechanoreceptors in the lateral elbow region of the rat.

The distribution and ultrastructure of sensory nerve endings were investigated in the deep lateral elbow region of the rat. Three zones of distribution of mechanoreceptors were distinguished, each in relation to the functional architecture of the connective and muscular tissue in that area: (1) a zone with muscle spindles, Golgi tendon organs, free nerve endings and single small lamellated corpuscles ('muscle-tendon spectrum'), situated in the middle third of the supinator muscle and its superficial aponeurosis; (2) a zone with small lamellated corpuscles and free nerve endings, situated pericapsularly to the humeroradial joint capsule ('shearing spectrum'): this moderately dense, irregular connective tissue is covered by the proximal continuation of the supinator's aponeurosis, and muscle fibers insert from beneath this aponeurosis, which displays, as a part of the joint capsule, a strong collagenous tissue plate; (3) a zone with only free nerve endings within the tendon-like, most proximal part of the supinator's aponeurosis, inserting into the periosteal layer of the lateral humeral epicondyle ('endotenonial spectrum'): it is part of the joint capsule. The ultrastructure of these sensory endings is described and the distribution pattern of the mechanoreceptors observed is discussed in relation to the classification into 'muscle receptors' and 'joint receptors'.

CGRP-like immunoreactivity in sensory nerve endings of the Golgi tendon organ. A light- and electron-microscopic study in the grey short-tailed opossum (Monodelphis domestica).

Using light- and electron-microscopic immunohistochemistry, it was shown that primary sensory nerve endings in Golgi tendon organs of the grey short-tailed opossum (Monodelphis domestica) contain immunoreactivities to a polyclonal antibody directed against calcitonin gene-related peptide (CGRP). Myelinated afferent axons (6-9 microns in diameter) of the Golgi tendon organs stained moderately for CGRP. Sensory nerve endings within the sensory compartment of the Golgi tendon organs displayed electron-dense accumulations corresponding to dark-brown staining in adjacent semithin sections. On the outer surface of tendon organs C fibre bundles were observed showing CGRP-like immunoreactivity.

Sensory innervation of the temporomandibular joint in the mouse.

The sensory innervation of the temporomandibular joints (TMJs) of 8 STR/IN mice was investigated by means of light and electron microscopy. Through the cutting of complete semithin sections in series it was possible to investigate the joints thoroughly. Additionally, one joint with its nerve supply was reconstructed three-dimensionally with a computerized three-dimensional programme. The reconstruction was based on one complete semithin section series. The joint's nerve supply originates from the nervus auriculotemporalis and additionally from motor branches of the n. mandibularis: n. massetericus, n. pterygoideus lateralis and the nn. temporales posteriores. The greatest number of nerve fibres and endings is located in the dorsolateral part of the joint capsule. They lie only in the stratum fibrosum and subsynovially. Neither the stratum synoviale nor the discus articularis contain any nerve fibres or endings, whereas the peri-articular loose connective tissue is richly innervated. The only type of nerve ending observed within the joint was the free nerve ending, which is assumed to serve not only as a nociceptor but also as a polymodal mechanoreceptor. Merely within the insertion of the musculus pterygoideus lateralis at the collum mandibulae single stretch receptors of the Ruffini type were observed. Ultrastructurally, they correspond to those described in the cat's knee joint. Neither lamellated nor nerve endings of the Golgi or Pacini type were observed in the joint or in the peri-articular connective tissue. The unexpected paucity of nerve fibres and endings in the TMJ itself of the mouse suggests that the afferent information from the joint is less important for position sense and movement than the afferent information from muscles, tendons and periodontal ligaments.

Cholinesterase activity in sensory-nerve endings, capillaries and motor end plates of the facial skin of the brush-tailed possum (Trichosurus vulpecula).

The facial skin of two adult and one 50-day-old pouch animal of the marsupial mammal Trichosurus vulpecula was removed after the animals has been suitably anesthetized and perfused for electron microscopy. Small blocks of tissue (1 x 0.5 mm) were cut and incubated in acetylthiocholine iodide substrate for cholinesterase studies. The blocks were then subsequently postfixed in osmium tetroxide. Thin sections were cut and stained with lead acetate. Specific cholinesterase was found within the nerves of both the adult and the 50-day-old pouch animal, and in the motor end plates. Nonspecific cholinesterase was present in pinocytotic vesicles and interlamellar spaces of terminal Schwann cells associated with nerve end organs in the adult, and in the same areas in Schwann cells of nonmyelinated nerves in the pouch animal. It was also present in the pinocytotic vesicles of the capillary endothelium.

Topography and ultrastructure of sensory nerve endings in the joint capsules of the Kowari (Dasyuroides byrnei), an Australian marsupial.

The present investigation in concerned with the topography and ultrastructure of sensory nerve endings in the joint capsules of the Kowari (Dasyuroides byrnei), an Australian marsupial. Material for light and electron microscopy was obtained from shoulder, elbow and knee joint capsules. On the basis of differences in the organization of the connective tissue belonging to the fibrous layer, 3 variants of capsule structure have been distinguished: a rigid, a flaccid and an intermediate type. Whilst the rigid type is characterized by dense connective tissue in the clearly demarcated fibrous layer, the flaccid type shows loose, irregularly arranged connective tissue in the fibrous layer which merges into the synovial layer of the joint capsule. The morphology of the intermediate type corresponds to an intermediate stage between the former two types. In the fibrous layer of the joint capsules three different types of sensory nerve endings were observed: free nerve endings, Ruffini corpuscles and lamellated corpuscles. The free nerve endings are supplied by myelinated afferent axons (1-2 microns in diameter); the terminal thickenings of which are incompletely surrounded by a terminal Schwann cell. Ruffini corpuscles are present in three different varieties: small corpuscles without a perineural capsule predominantly within the flaccid part of the capsule; slightly larger corpuscles with an incomplete perineural capsule and large corpuscles resembling Golgi tendon organs which predominantly occur in the rigid parts of the capsule. The afferent myelinated axons measure 2-4 microns in diameter. The lamellated corpuscles show two variants: small corpuscles with a 2 to 4-layered perineural capsule in the rigid parts of the joint capsules and large corpuscles with two longitudinal clefts of the inner core in the flaccid parts. Both types are supplied by myelinated axons of 3-5 microns in diameter. Thus, in the fibrous layer of the rigid type of joint capsules large Ruffini and small lamellated corpuscles predominate, whereas the fibrous layer of the flaccid type coincides with small Ruffini and large lamellated corpuscles. The present data, therefore, corroborate the concept that the morphology of mechanoreceptors depends upon the texture of the surrounding connective tissue.

[Axial mesenchyme structure in the anlage of the human vertebral column. Light microscopy study of a human embryo of 9 mm CRL (Carnegie stage 16)]. / Axiale Mesenchymstrukturen in der Anlage der Halswirbelsäule des Menschen. Lichtmikroskopische Untersuchung eines menschlichen Embryos von 9 mm SSL (Carnegie-Stadium 16).

The anlage of the cervical vertebral column of a human embryo has been investigated (9 mm CRL, Carnegie stage 16). The nuclear density in the axial mesenchyme increases rhythmically from cranial to caudal. This phenomenon superimposes a metameric pattern on the blastema. Furthermore, cell formations are shaped by the orientation of the mesenchymal cells. The name 'formationes quasi distensae' is proposed for this system. The anlage of the atlas shows a distinct mesenchymal anlage of a vertebral body. The conclusion is drawn that the dens axis is predominantly formed out of the anlage of the atlas body. The opinion that man does not show an anlage of the atlas body can no longer be sustained.