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The purpose of this study is to investigate carpal kinematics with respect to the pisotriquetral joint, before and after pisi-form excision. Five cadaver-hands were studied and a custom-designed plexi-glass-fixation device was used to standardize the wrists for exact passive movements in flexion and extension as well as in ulnar and radial abduction. Five sets of motion were registered before and after excision of the pisiform. Motion of the triquetrum and pisiform were studied by 3D-Motion Analysing Software System (peak 54). The results indicated that the excision of the pisiform does have an influence on the kinematics of the wrist. The movement of the triquetrum was increased after removal of the pisiform. Although the differences in measurement were only a few of millimetres and degrees, we know from the dorsal and palmar intercalated segment instabilities that even minor instabilities can act as a predisposing factor for arthrosis. Therefore, the excision of pisiform must be carefully considered. The common joint between the triquetrum and pisiform supports and indicates relation of their movements. However, the correlation for flexion/extension and radial deviation was high, an obvious correlation of the movements for ulnar deviation was not verifiable.

Although the relevance of capillary and gliding spaces of the back of the hand and the finger located dorsal to the extensor aponeurosis in the metacarpo-phalangeal region between the layers of the subdermal connective tissue is often emphasized clinically in inflammatory and acute traumatic occurrences, hardly any information has been published concerning the morphology of these spaces. By means of plastic-injection techniques, varying configurations of capillary spaces in the distal region of the dorsum manus of cadavers were found. The deep connective tissue spaces located dorsal to the extensor aponeurosis were shown to have proximal connections to the dorsal tendon sheaths of the carpus, whereas superficial gliding spaces tended to vary in their expanse depending on the subcutaneous and epifascial septa. The deep as well as the superficial capillary gliding spaces are adapted as mobilizing and limiting structures for the movements of the metacarpo-phalangeal joints and the various mechanical stresses of the skin of the back of the hand. A high degree of exactness in the reconstruction of the marginal elements of such functional spaces appears to be of special importance with regard to a total restoration of the functional capability of the metacarpo-phalangeal joint region.

A pronounced valgization or varization of the lower extremity leads to changes in skeletal muscle which are histologically and morphometrically demonstrable in biopsies of Mm. vastus lateralis et medialis of patients with chronically anomalous stressing of the knee joint. During chronic over-stressing, increased thickness in type I and type II muscle fibers can be observed in both Mm. vastus medialis and lateralis, whereas type II fibers demonstrate a greater variability and there is a greater occurrence in type I fibers. Our investigations show that a chronic anomalous stressing influences both the size and energy metabolism of a skeletal muscle cell in a manner which can be interpreted as a functional adaptation.

Alterations of the spatial geometry of the carpal tunnel and its contents during dynamic stress situations of the wrist are of importance in clarifying morphological causes of a carpal tunnel syndrome. In order to demonstrate the changes occurring in the form of the carpal tunnel and the location of its contents during wrist movement, casts of the carpal tunnel were produced from the hands of cadavers in flexed and extended positions. The casts were then morphometrically analyzed and the movements of the median nerve and the flexor tendons were examined radiologically. The investigation showed that a delicate equilibrium exists between the capacity of the carpal tunnel--whose hourglass shape typically changes to suit dynamic stress situations--and the volume of its contents. Spatial processes extending from the carpal tunnel wall or emanating from the structures contained within the carpal tunnel may exceed the system's ability to compensate for extreme positioning of the wrist and thus induce compression symptoms of the median nerve.

In the following study, the basal joint of the thumb and its neighboring joints of 100 anatomical specimens were inspected radiologically and macroscopically for arthrotic alterations. The comparison of the radiological and macroscopic findings showed that early arthrotic joint alterations cannot be diagnosed by radiograms. Virtually half of the specimens examined demonstrated arthrotic lesions of the basal joint of the thumb, whereas the trapezio-scaphoidal and trapezoido-scaphoidal joints were only affected in one-third of the specimens. Two-thirds of the cases with manifest arthrosis of the metacarpophalangeal joint of the thumb demonstrated additional arthrotic changes in the joints between the scaphoid, trapezium, and trapezoideum. No macroscopic evidence of arthrotic alterations in the remaining radial carpal bones were observed. The architecture of the capsular and ligamentous apparatus as well as the individual variations in the scaphoid bone have both been discussed as possible causes of these phenomena, as were polyarthrotic or secondary arthrotic processes.

Arthrography of the proximal wrist joint does not provide details regarding the shape and the extension of the recessus ulnaris. The recessus located between the ulnocarpal disc and the meniscus homologue as a diverticulum of the articular lining was examined in 61 wrists by arthrography and dissection. Using the Pleximon-injection technique, specimens of the proximal wrist cavity allowed a systematic description of morphology and topography of the ulnar recessus. The shape and location of the ulnar recessus show variations, but a sacciform recessus, which usually bears a close relationship to the ulnar styloid process, is the most common. The comparison of arthrographic and morphologic findings allows an assessment of the credibility of arthrographic depictions of the wrist as regards the clinically relevant close relationship to the recessus ulnaris.

Apart from the first carpometacarpal joint, the fifth carpometacarpal joint is of importance in gripping and cupping the hand. The present study describes the functional anatomy of the fifth carpometacarpal joint considering morphological and experimental findings. Shape and extension of the cartilaginous articular surface of 50 metacarpal bases show characteristics of a saddle joint. The differences between the dorso-palmar and ulno-radial curvature of the articular surface suggest a main direction of motion in the fifth carpometacarpal joint around an ulno-radial axis. Flexion in this joint ranges from 10 to 15 degrees. After maximal flexion, a supinatory rotation of the metacarpal bone ranging from 10 to 15 degrees is measured. Because of the transverse arched configuration of the carpal bones, the flexion of the fifth metacarpal bone produces opposition towards the thumb. A simultaneous supinatory rotation supports this opposition movement.

Especially the identification of rotational malunions on the distal radius is difficult by routine diagnosis. Long-time effects like a chronic loss of articular surface of the posttraumatic rotation on the distal radioulnar joint are of clinical importance. Evading expensive diagnostic methods like CT simulated rotational malunions of the radius are quantitatively investigated on the basis of routine X-ray pictures only. The geometrical relation between the rotational angle of the radius and the two-dimensional distance from the dorsal to the volar border of the radial notch is described by a simple trigonometrical function. Considering morphological individualities of the radial notch and the rotational angles of right and left radii rotational malunions below 10 degrees are discovered and their effects on the forearm skeleton are assessed.

The dorsal approach to the metacarpal bones is through the peritendinous connective tissue of the extensor tendons. Knowledge of the vascular supply of the distal parts of these tendons, between the distal end of the tendon sheath and the tendon's osseous insertion is important, especially with respect to atraumatic technique. The course and distribution of the vessels to the extensor tendons II-V were investigated. Superficial and deep layers of connective tissue were found to contain blood vessels. The superficial vessels reach the dorsal aspect of the extensor tendon, originating from subcutaneous arteries and the large arteries of the hand. The deep vessels reach the lateropalmar aspect of the tendons and originate from the peritendinous muscular arteries. Vessel distribution suggests a direct relationship between the number of nourishing arteries and the tendon surface area. The vascular supply to the unsheathed parts of the extensor tendons shows morphological adaptations to differential mechanical stress during tendon excursion.

Posttraumatic angular and rotatory deformities of radius or ulna or both frequently cause a restriction of supination-pronation. The loss of motion is determined by the direction and the degree of angulation and by location of fracture. The dorsopalmar angulation and radioulnar deviation of the radius in an anatomic forearm specimen are simulated and the motions of the radius during supination-pronation are investigated. Dorsal angulation and radial deviation produce a considerable loss of pronation. However, supination losses are much less affected. The reduction of the interosseous gap is an important morphological reason of this effect. The angle of torsion is measured in left and right intact radii between transversal epiphyseal and diaphyseal axes. The torsion of the distal radial epiphysis varies from 0 to 16 degrees. Left and right radius of a single individual show very small differences in their torsion; therefore a comparison to the intact contralateral bone is indicated.

Assessing radial and ulnar rotational deformities quantitatively by routine diagnosis after healed distal forearm fractures is very difficult. A method to obtain information about direction and graduation of malrotation is described. This method is based on discovering topographic changes of skeletal points by CT. Rotational angles of intact forearm bones are measured on anatomic specimen and in vivo using epiphyseal and diaphyseal axes of the radius and the ulna. Normal rotation of intact forearm bones varies in a specific manner. The radius presents less variations than the ulna. A morphological index of radial and ulnar rotation is not given because of the great individuality of diaphyseal rotation. Both radii of a single individuum show a very small rotational difference. Therefore a verification of malrotation is indicated by comparison to the intact opposite radius. Higher rotational graduations on the left side have to be noted.

Pathological changes of wrist bones and ligaments after radial fracture loco typico induce permanent functional restriction and pain. In this paper the effects of malunion on the distal radioulnar joint are investigated and osteotomic therapy of Kienböck's disease gets a new evaluation. By simulating radial malunions on anatomic forearm specimen the effects of these malunions on the contact area during supination, neutral position and pronation are measured. Isolated posttraumatic radial shortening as well as epiphyseal inclination and torsion cause a reduction of radioulnar contact. During supination and pronation the loss of radioulnar contact increases. Most significant reduction of contact takes place at a lower graduation of radial malunion. Pronatory torsion of distal radius compensates for a radioulnar contact reduction from combining dorsal inclination with radial shortening. One conclusion of this paper is an exact restitution of anatomical relations between ulnar head and radial notch after fracture of the distal radius.

Morphological changes subsequent to malunion of distal radius fractures involve altered bone density along articular surfaces and wrist ligaments. The inclination of articular surfaces of the scaphoid and lunate in frontal and sagittal planes frequently leads to a dorsal dislocation of the distal fracture fragment. X-ray densitometry of subchondral mineralization shows zones of higher density along the palmar articular border, resulting from excentric load transmission. Typical morphological changes involving wrist ligaments are demonstrated and analyzed.