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Biomedical subjects

H M Schmidt

Publications and source records attributed to H M Schmidt.

At least 37 records · Page 2Linked to original sources
PubMed1994

Vascularization of the fetal elbow joint.

Unlike the adult tissue, prenatal cartilage may be well vascularized. We studied the prenatal development of vascular channels within the epiphyses of the human elbow joint. Plastinated 200-1000 microns thick sections through the right and left arms of 12 fetuses with a crown-rump-length of 90-360 mm and of a newborn infant were investigated. Cartilage canals first develop within the distal humeral epiphysis, later on within the olecranon process and the radial head. With advancing age, the canals reveal an increasingly complex pattern of distribution. However, a constant basic pattern can be recognized at every developmental stage. The cartilage canals take their origin from the perichondrium. At their point of entrance into the cartilaginous tissue, their walls are often ill-defined and consist of several fibrous layers which gradually irradiate into the cartilage. At the opposite tip, the channel wall is more clearly demarcated. Many cartilage canals contain several vessels forming loops or branching into bunch-like structures at the tip of the canals. The vessels mostly lie adjacent to the canal walls, grouped around a core of loose connective tissue. As a rule different channels run towards the centre of the cartilage and do not form any anastomoses. The vascularization of the epiphyses of the human elbow joint takes place a long time before the secondary centres of ossification develop, which normally appear after birth. Thus, a direct causal relationship seems unlikely.

Adult↗
PubMed1994

Cartilage canals in the fetal elbow joint in man.

The development of cartilage canals in the human elbow joint during fetal life was studied. Plastinated 600-1,000-microns-thick sections through the right and left arms of 12 fetuses with a crown-rump length of 90-360 mm and of a newborn infant were investigated. At a crown-rump length of 90 mm, cartilage canals have started to develop well within the distal and inferior aspect of the capitulum of the humerus, and are about to enter the dorsal side of the olecranon process. The radial head shows that vascularization does not begin before the 160-mm stage. The channels reveal a centripetal orientation and do not form any anastomoses. Branching occurs mainly in a dichotomous manner. The channels never originate from those areas of the perichondrium which reveal regular and parallel or very dense but irregular anchorage of collagenous fibres into the adjacent cartilaginous tissue.

Cartilage, Articular↗
PubMed1994

[Clinical anatomy of the interosseous arteries of the forearm].

In recent years, several local flaps have been developed, based on the anterior and posterior interosseous arteries and their anastomoses at the wrist (e.g. posterior interosseous flap, pronator quadratus flap etc.). The anatomy of the arterial network supplying the flap is well established in both clinical and anatomical literature. Most authors agree in the constancy of the anastomoses between the interosseous arteries at the wrist and the absence of major anatomical variations excluding the use of the flap. In the present study, which is based on cadaver dissections of 60 preserved specimens, several gross vascular variations of the interosseous arteries have been found. The most frequent types were an additional anastomosis between the posterior interosseous artery and a perforating branch of the anterior interosseous artery in the middle third of the forearm, which was found in 20%. Ring-formations of the palmar and the dorsal branch of the anterior interosseous artery occurred in 5%. The point of perforation of the interosseous membrane by the dorsal branch of the anterior interosseous artery was found to vary in a larger extent, as described previously.

Aged↗
PubMed1993

Clinical anatomy of the subcutaneous veins in the dorsum of the hand.

Ninety adult upper extremities from human cadavers were used to study the patterns of the subcutaneous veins in the dorsum of the hand, with careful dissection and measurement under magnification. In our series, the distribution of the veins was not symmetrical in the dorsum of the hand. In 83.3% of the cases, the veins were arranged in two groups, radial and ulnar, above the transverse midline of the dorsum. The area between these two groups, corresponding to the proximal halves of the second metacarpal bone, the second intermetacarpal space and the third metacarpal bone, might be called "vein lacking area". Crossing branches of veins were found in all cases. There were on average three crossing branches in each case, and their internal diameters were 0.9 +/- 0.2 mm. This study established that the subcutaneous veins in the dorsum of the hand are arranged in two layers. They communicate freely with the veins in the palmar aspect through the intermetacarpal spaces. The average number of perforating branches was 3.9, and their internal diameters were 1.0 +/- 0.4 mm. The perforating branch in the first intermetacarpal space was wide (internal diameter: 1.8 +/- 0.3 mm) and very constant (appearance rate: 100%). This branch may be the most important communication between the superficial and deep veins. We found the venous values in 70.0% of the perforating branches, which prevent the blood flowing from the dorsum to the palm.

Adult↗
PubMed1993

[Prenatal development of the radial annular ligament].

The prenatal development of the annular ligament of the elbow was studied by investigating 600 microns thick plastinated sections through the elbow joints of nine fetuses with a crown-rump-length (CRL) of 105-360 mm. At 105 mm CRL the annular ligament consists of one layer of circular fibres around the circumference of the radial head. At 130 mm CRL it extends further distally to the radial neck. The postero-lateral region exhibits an arrangement of three layers of fibres of different course. Stages later than the 190 mm stage show in the anterior region external fibres arising from the medial periosteum of the ulna. They pass over the anterior surface of the ulna and blend with fibres arising from the anterior margin of the ulna's radial notch to surround the radial head. At 270 mm the articular capsule can be recognized as a strong homogenous layer of fibres. With all stages investigated the annular ligament consists of circular fibres only near the attachment at the posterior margin of the ulna's radial notch. Anteriorly the annular ligament is narrower than posteriorly. With the later stages of 290, 330 and 360 mm CRL a further differentiation of the annular ligament cannot be recognized. Thus, between 105 mm and 270 mm CRL, the annular ligament develops a more and more complex structure similar to that described for the adult joint. We describe several distinct steps of this differentiation during the fetal period which are not mentioned in the literature yet.

Cell Differentiation↗
PubMed1993

[Clinical anatomy of the fat body in the forearm and in the palm].

In the hand the space between the deep flexor tendons and the interosseous fascia is named the midpalmar space, spatium palmare medianum. A fat body, Corpus adiposum palmare profundum, can be found there regularly. Despite the anatomical narrowness in this region, it reaches up into the carpal canal. Also in the deep forearm space there is always a fat body, Corpus adiposum profundum antebrachii, located dorsally to the deep flexor tendons, lying on the palmar fascia of the pronator quadratus muscle. Usually it is not connected to the Corpus adiposum palmare profundum. The regular occurrence of both fat bodies indicates their functional importance. It is to be supposed that they serve as a gliding layer for the deep flexor tendons. Especially the Corpus adiposum palmare profundum may provide an essential protecting function to the dorsally located deep branch of the ulnar nerve and deep palmar arch. In contrast there is a higher risk of mechanical irritation and compression of the deep branches of the ulnar nerve and artery during their more proximal course through the opponens muscle of the little finger ("opponens-canal") and the ulnar marginal septum. Characteristic features of dimensions and location of the Corpus adiposum profundum antebrachii and the Corpus adiposum palmare profundum and of the deep branches of the ulnar nerve and artery are described. The clinical relevance is discussed.

Adipose Tissue↗
PubMed1990

[A rare anomaly of the superficial flexor tendons of the little finger].

A rare anomaly was found in both hands of an eighty-five-year old female. The muscle bellies of the superficial finger flexor muscle for the little finger were absent. Instead of this, a thin tendinous cord arose from the tendon of the flexor superficialis of the ring finger proximal to the carpal tunnel to pass into the radial side of the flexor tendon sheath of the little finger at the level of the annular ligament A 1. Together with an abortive tendon on the ulnar side the tendon inserted into the middle phalanx. The flexor digitorum profundus muscle of the little finger was normal.

Aged↗
PubMed1990

[Clinical anatomy of the digital connective tissue cord of the ulnar side of the little finger].

A fibrous cord with a length of nearly 60 mm and a width of 3 mm consistency starts near the insertion of the abductor digiti minimi muscle at the ulnar border of the little finger. The fibers pass parallel to the longitudinal direction of the little finger and at the level of the osseous ridges on the palmar side of the flexion-extension axis of the finger joints. Proximally the cord receives fibers from the periosteum at the base of the proximal phalanx, from the ulnar end of the natatory ligament, and from the pretendinous fibers of the A1 pulley. Distally the digital cord has connections to the cutaneous ligaments of Grayson and Cleland. The cord also joins the flexor tendon sheath, the neurovascular bundles, and the skin. Sometimes these cords are involved in Dupuytren's contracture.

Adult↗
PubMed1990

Cutaneous ligaments of the human hand.

A topographical study concerning the cutaneous ligaments of adult as well as human fetal hands was performed. In order to be able to preserve the cutaneous ligaments in their entirety two different methods, a careful dissection and a new histological technique, have been employed. The results of these methods are compared and the detailed topography of the different cutaneous ligaments is clarified. In addition to topographical details, the functional co-operation of the ligaments especially in regard to their clinical relevance is reported.

Adult↗
PubMed1989

[The computer-assisted spatial reconstruction of the hip acetabulum].

Computer aided design is a useful method in presenting graphics. By 2 simple computer programs written in BASIC and running on most home computers very clear plots of the 3-dimensional (3D) structure of joints like the acetabulum can be drawn quickly. By orthogonal transformations the 3D-body may be easily regarded from every possible point of view. The surface of the acetabulum may be emphasized by an optional automatic hatching between adjacent cutting bows. Further methods of automatic data entering from given joints are discussed.

Acetabulum↗
PubMed1988

[The 'loge de Guyon'. A contribution to the clinical anatomy of the human hand].

In 40 hands of adults the 'loge de Guyon', a narrow bounded area within the proximal hypothenar region, has been dissected to realize an exact determination of the important characteristics of size. Beside measurements of the wall structures in the region of the pisiform bone, the hook of hamate and the entrances of the loge, variations of muscles and the position of the ulnar artery and nerve with their terminal branches have also been examined. The deep palmar branch of the ulnar artery crosses the rami of the ulnar nerve on the palmar side in 65% of cases. The branch of the artery crosses on the dorsal side in 30% and in 5% the ramus profundus of the ulnar artery runs between both terminal branches of the ulnar nerve. The clinical significance of the loge is emphasized, whereas the irregular nomenclature in the national and international literature is discussed in detail.

Hand↗
PubMed1988

[Studies on the tendinous compartments of the extensor muscles on the back of the human hand and their tendon sheaths. I].

In 47 dissected right and left hands of adults of both sexes, kept in a moist condition, significant practical-clinical investigations of the transitional zone between forearm and hand were undertaken. In particular it was sought to determine the characteristic sizes of the extensor retinaculum, the osteofibrous tunnels, the insertion tendons of the hand and finger extensor muscles, and their tendon sheaths. Together with the palmar carpal ligament, the 2 to 3 cm wide extensor retinaculum annularly surrounds the whole circumference of the carpus. It extends obliquely from radial-proximal to ulnar-distal and conducts the extensor tendons over the carpal articulations. According to recent studies, it is divided into a superficial and a deep fibrous layer. From the undermost surface, vertical and oblique septa run to the plane of the forearm and carpal bones. They separate the fibrous portion of the 6 tendinous compartments of the dorsum manus. In 8.5% of cases, an accessory and completely independent tunnel of the extensor pollicis brevis muscle exists in the material investigated, and in 2.2% of cases, there is an additional tunnel for the extensor carpi radialis muscle. Hence, one occasionally finds 8 separate osteofibrous gliding compartments for the extensor muscles in the dorsal hand region. The longest tunnel belongs, as a rule, to the extensor digiti minimi muscle, whilst the widest pertains to the extensor digitorum muscle. Within the tunnel and also proximal and distal to it, the extensor tendons are surrounded by synovial sheaths. Because of its wide encroachment on the dorsum of the hand, the insertion tendon of the extensor digiti minimi muscle possesses the longest tendon sheath, measuring 68.8 mm. The next longest sheath, that of the extensor pollicis longus muscle, which measures 56.2 mm, begins further proximal to the gap of the radiocarpal articulation. In 12.8% of cases, there are divided sheaths of the abductor pollicis longus and of the extensor pollicis brevis muscle. The tendon sheath of both extensor carpi radiales muscles is frequently divided into 2 compartments which, in 2/3 of cases, communicate. The compartment of the extensor carpi radialis brevis muscle, in 91.5% of cases, shares a window-like opening with the roof of the synovial vagina of the extensor pollicis longus muscle. The tendon sheath of the long extensor muscles of the fingers originates 5 mm proximal to the forearm border of the extensor retinaculum and has a communal recess. The IVth tendon sheath opens distally and splays out in a glove-like manner to some distal recesses.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1987

Clinical anatomy of the m. flexor carpi radialis tendon sheath.

At the transitional zone from the forearm to the hand the insertion tendon of the m.flexor carpi radialis (FCR) glides on a fibrous and fatty cushion, which is connected dorsally with the joint capsule of the radiocarpal articulation. The tendon distally crosses the palmar side of the scaphoid tubercle and enters the dorsally curved rim of the trapezoid tubercle. At the level of the wrist joint the narrow tendon sheath begins, which extends to the insertion at the metacarpus. Immediately after entering the gliding tunnel the tendon branches off radially as a rule with an accessory fibre strand 8 mm in width to the scaphoid, trapezium and the joint capsule between these two bones. The insertion tendon regularly is attached to the palmar and radial surfaces of the second and third metacarpal bones. The wall of the osteofibrous gliding tunnel can be prominent following trauma, inflammation or arthrosis deformans in the trapezio-scaphoideal joint and may irritate the tendon (tendovaginosis stenosans). Against resistance forces pain will occur in the wrist joint during palmar flexion. The typical point of tenderness is situated at the entering of the tendon in the thenar region. Operative decompression will be effective by opening the radial wall of the tendon sheath from the carpal tunnel.

Female↗
PubMed1987

[Clinico-anatomic studies of the carpal tunnel of the human hand].

Numerous investigations of the carpal tunnel were performed in 60 human hands of adults. In detail we determined the length, width, and thickness of the flexor retinaculum. Furthermore the dimensions of the carpal tunnel and the proximal, middle and distal cross-section areas were calculated. We found that the middle region is the narrowest portion of the carpal tunnel. The median nerve increases constantly in width from proximal to distal in the carpal tunnel whereas its thickness decreases. In 43.3% the nerve passes radially from the middle of the tunnel to the palm. In 21.7% the median nerve is located exactly under the middle of the flexor retinaculum and only in 1.7% is it shifted to the more ulnar side. The median nerve shows a winding course in the remaining cases.

Adult↗
PubMed1986

[Connective tissue reinforcing structures of the digital tendon sheaths of the human hand].

At a greater number of humid preparated human hands, all the ligamentous supports of the digital tendon sheath were exposed and their dimensions were determined. The osteofibrous channels, which contain the long flexor tendons of the digits, were bounded on the one hand by transversely concave shaft areas of the phalanges and the palmar ligaments and on the other side by the fibrous parts of the tendon sheath. From the second to the 5th finger, it has a regular extension of length, which begins proximal at the heads of the metacarpal bones and runs distal to the base of the nail phalanx. In some cases, there is a continuous communication between the digital tendon sheath of the little finger and the carpal synovial sheath. The tendon sheath of the flexor pollicis longus muscle in comparison with it is always in an open communication with the radial synovial sac of the wrist. At the fibrous supports of the digital tendon sheath, one can find constant and inconstant ligamentous structures. Regular shaped ligaments consist of annular fibers (A1 to A5). The proximal complex of fiber supports is a formation of the A1 and A2 ligaments. The band A1 can be divided into 2 ligaments both of roughly equal length, which lay between the head of the metacarpal bone and the base of the proximal phalanx. The strongest fibrous support of the whole digital tendon sheath represents the band A2. It is attached to the midth of the proximal phalanx and increases in strength from proximal to distal. The middle length varies between 6.7 mm at the thumb and 18.7 mm at the middle finger. The distal margin is strengthened by fibrocartilage tissue to be in accordance with the important function as a pulley. The annular band A4 forms the distal supporting complex height above the shaft of the middle phalanx. At the 2nd to the 5th finger it is, with a middle length of 6 to 7 mm, very much shorter than A2 and restrains first of all the tendon of the flexor digitorum profundus muscle. In the area of the interphalangeal joints, we can find the annular bands A3 and A5, which fiber texture is formed variable. Both ligaments are attached on either both sides with the joint capsule and the palmar plate. The other inconstant supports of the digital sheaths are systematically recorded indeed (C1 to C3), but only in exceptional cases they exist of cruciform fibers (Lig. cruciatum).(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1985

[Glide amplitude of flexor and extensor tendons of the fingers of the human hand].

The gliding amplitude of the flexor and extensor tendons of the finger muscles were determined in the human hands of adults. The carpometacarpal transition area and also the middle zone of the proximal and middle phalanx were appointed as measuring marks. In the main the amplitudes on the flexor side are constantly greater than on the extensor side. Because the movements decrease from proximal to distal, also the gliding range during tendon excursion lessens in the proximo-distal direction. In the case of replantation the extensor tendons should be shortened by the same amount as the bone. To relieve tension in the suture, the flexor tendons should be kept at their original length.

Aged↗