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Purpose: Distal humeral fractures are rare, but severe injuries, the treatment of which is often accompanied by serious complications and its outcome strongly depends on the quality of surgical therapy. Non-union is a common entity, compromising clinical results and requiring revision surgery. Osteonecrosis is an underestimated etiologic factor in the development of non-union. The present study aims to display the distribution patterns of the arterial vessels at the distal humerus, to correlate the displayed vessels with local nutrient foramina and to disclose an endangerment of these structures by common osteosynthetic implants., Methods: Eight plastinated fresh frozen upper extremities were digitally analyzed regarding the vascular density of the cancellous bone, by calculating the ratio of area comprised by arterial vessels and the area comprised by cancellous bone on sagittal cuts of the distal humerus. Possible differences in the vascular density of the medial epicondylar region, the lateral epicondylar region and a watershed area between the epicondyles and distal to the supracondylar region were investigated. On the basis of 200 macerated humeri, the distribution pattern of cortical nutrient foramina and their anatomic relation to properly applied common distal humerus plates were documented., Results: The data show a significantly higher density of vessels per cancellous bone in the epicondylar regions than in the watershed region (p < 0.000, median 0.148 vs. 0.103). The analysis of the nutrient foramina showed distinct distribution patterns with a single foramen over the medial epicondyle (55 specimens, 27.5 %) and an area of several foramina at the posterior part of the lateral epicondyle (200 of the specimens, 100 %). In almost every specimen, the application of the osteosynthetic implants led to an overlay over the investigated nutrient foramina., Discussion: Osteonecrosis and non-union are severe complications in the surgical treatment of distal humeral fractures. The biology of the bone, especially the blood supply, has to be respected as much as possible during open procedures, to optimize bony healing. This has to be considered when performing periosteal stripping or applying osteosynthetic plates over the postero-lateral and medial epicondyle. The watershed area of the distal humerus has to be considered as being prone to minor arterial blood supply and thereby non-union is possible, if the arterial vessels coming from the epicondyles are destroyed.

Purpose: To detect the variable relationship between sciatic nerve and piriformis muscle and make surgeons aware of certain anatomical features of each variation that may be useful for the surgical treatment of the piriformis syndrome., Methods: The gluteal region of 147 Caucasian cadavers (294 limbs) was dissected. The anatomical relationship between the sciatic nerve and the piriformis muscle was recorded and classified according to the Beaton and Anson classification. The literature was reviewed to summarize the incidence of each variation., Results: The sciatic nerve and piriformis muscle relationship followed the typical anatomical pattern in 275 limbs (93.6 %). In 12 limbs (4.1 %) the common peroneal nerve passed through and the tibial nerve below a double piriformis. In one limb (0.3 %) the common peroneal nerve coursed superior and the tibial nerve below the piriformis. In one limb (0.3 %) both nerves penetrated the piriformis. In one limb (0.3 %) both nerves passed above the piriformis. Four limbs (1.4 %) presented non-classified anatomical variations. When a double piriformis muscle was present, two different arrangements of the two heads were observed., Conclusions: Anatomical variations of the sciatic nerve around the piriformis muscle were present in 6.4 % of the limbs examined. When dissection of the entire piriformis is necessary for adequate sciatic nerve decompression, the surgeon should explore for the possible existence of a second tendon, which may be found either inferior or deep to the first one. Some rare, unclassified variations of the sciatic nerve should be expected during surgical intervention of the region.

Purpose: A bilateral fixed-angle plate was biomechanically compared to the two currently preferred methods of osteosynthesis for transverse patella fractures. It was hypothesized that the new angle-stable implant would provide a secure and sustainable fracture fixation, superior to the established standard techniques., Methods: Twenty-one identical patellae made of polyurethane foam (Sawbones(®)), osteotomized to create a transverse two-part fracture, were fixed with modified anterior tension wiring, cannulated lag screws with anterior tension wiring or bilateral polyaxial 2.7-mm fixed-angle plates. The testing protocol consisted of 10,000 repetitive cycles using a non-destructive physiological load between 100 and 300 N at a simulated knee flexion of 60°., Results: All 21 Sawbone(®)-patellae sustained repetitive loading up to 10,000 cycles without failing. The anterior tension wire group displayed significant displacement of the fracture gap (0.7 ± 0.2 mm) during cyclic loading, while both lag screws with tension wiring and bilateral fixed-angle plates showed no fracture gap widening at all (p < 0.01)., Conclusion: The bilateral fixed-angle plate and cannulated lag screws with anterior tension wiring preserved a constantly reduced fracture gap over 10,000 tensile cycles in contrast to modified anterior tension wiring, which exhibited significant widening of the gap after initial loading. Results of in vitro testing indicate that bilateral fixed-angle plates provide sustainable fixation stability offering a promising new option in the treatment for transverse patella fractures.

Purpose: Displaced tibial eminence fractures require surgical fixation in order to obtain a stable knee joint. Suture fixation with FiberWire(®) seems to be the most favorable therapeutic option. Biomechanical studies show failure of this technique most commonly due to a suture cutout with subsequent fracture of the tibial eminence fragment. The goal of this study is to compare the biomechanical properties of three different techniques of suture fixation using FiberWire(®)., Methods: Bone mineral density was evaluated in 18 human knee specimens by pqCT, and three similar groups were formed. A standardized anterior tibial eminence fracture was created, and suture fixation was performed using one of three different techniques in 6 specimens each. Cyclic and destructive testing was conducted., Results: Significant differences between the three techniques could be shown neither in the cycles needed to achieve a steady state nor in a failure load or initial stiffness. Almost all specimens failed by suture cutout., Conclusion: The presented modification of the existing technique for suture fixation of tibial eminence fractures did not lead to an increased initial stability nor did it lower the rate of suture cutout. All tested suture techniques showed comparable initial stiffness and failure load.

The mechanisms of injuries to the tibiofibular syndesmosis include isolated rupture and rupture in combination with ankle fractures. Current concepts of surgical treatment are fixation using bioabsorbable screws, syndesmotic stapling, syndesmotic hooks, and the widely used screw fixation. Postoperative care utilises passive motion of the ankle joint either with or without axial weight-bearing. The aim of our investigation was to quantify the motion of the mortise during axial load. Therefore, photoelastic tests, on the one hand, and biomechanical tests of cadaveric specimens, on the other, using axial loads of up to 2,000 N were used. Our photoelastic investigations showed force distribution through the screw into the cranial and caudal parts of the distal fibula. Biomechanical testing showed a progressive dehiscence in both ruptured and fixated specimens up to 2.89 (ruptured) and 2.42 mm (despite screw). Our findings strongly suggest a concept of partial weight-bearing at most to support regeneration of scar tissue and to prevent the appearance of instability in the ankle joint.

Purpose: Treatment options for hallux rigidus include several conservative and surgical measures. The aetiology leading to the disease has not sufficiently been examined so far., Materials and Methods: We analysed the anatomical configuration of the first metatarsal head of 120 metatarsal bones of different collectives aiming to find a possible correlation between the geometry of the first metatarsophalangeal joint and manifestation of hallux rigidus. Wet human cadaveric specimens and macerated dry specimens served as material. The relevant parameters used for analysis were an axis running through the metatarsal head, the anatomical longitudinal axis, and the radius of curvature of the first metatarsal bone., Results: A significant difference was found in the radius of curvature of osteoarthritic and healthy subjects. Using the binary logistic regression, we were able to predict the probability of an occurrence of hallux rigidus in dependence of the radius of curvature. Furthermore, we were enabled to calculate a correct prediction for the appearance of osteoarthritis in 85 % of the healthy subjects, and 73 % of the osteoarthritic subjects., Conclusions: A consolidated view of the factors indicates that persons with a high risk for the appearance of hallux rigidus should be identified by measuring the radius of curvature in conventional radiographs and preventive measures to postpone the occurrence of clinically relevant hallux rigidus considered.

The functional influence of the medial collateral ligament on the medial meniscus is still discussed controversially. Commonly, a strong fixation of the meniscus by the collateral ligament is described. Injury to the medial meniscus is explained by its reduced mobility due to its strong adherence to the medial collateral ligament. The analysis of 10 plastinated series of the medial femorotibial compartment prove that only few fibres of the ligament radiate into the meniscus. To define the possible contribution of these fibers to the stability of the medial meniscus, experiments on two fresh frozen knee joints were performed. The distal femur was separated by cutting the capsule. The medial collateral ligament was detached carefully from its femoral insertion. The tibial head with both menisci was fixed in a clamping system. A translucent, exact acrylic glass copy of the femoral component to which the medial collateral ligament was reinserted, allowed studying the behaviour of the medial meniscus under axial compression (500 N). Firstly, stress was applied while the collateral ligament was proximally fixed and under tension; then the same experiment was performed after femoral detachment of collateral ligament. All plastinated series revealed only some deep and tender fibrous bundles of the medial collateral ligament radiating into the medial meniscus proximally and posteriorly. The behaviour of medial meniscus was exactly the same in both stress experiment series. The conclusion is that there is no relevant influence of the medial collateral ligament on the stability of the medial meniscus.

Side-to-side comparison of anatomical or functional parameters in the evaluation of unilateral pathologies of the human knee joint is common practice, although the amount of symmetry is unknown. The aim of this study was to test the hypothesis that there are no significant differences in the morphometric knee joint dimensions between the right and the left knee of a human subject and that side differences within subjects are smaller than intersubject variability. In 20 pairs of human cadaver knees, the morphometry of the articulating osseous structures of the femorotibial joint, the cruciate ligaments, and the menisci were measured using established measurement methods. Data were analyzed for overall side differences and the ratio between within-subject side differences and intersubject variability was calculated. In three out of 71 morphometric dimensions there was a significant side difference, including the posterior tibial slope, the anatomical valgus alignment of the distal femur, and the position of the femoral insertion area of the ACL. In two additional parameters, including the cross-sectional area of the ACL and PCL, within-subject side differences were larger than intersubject variability. In general, there was a positive correlation in morphometric dimensions between right and left knees in one subject. It is concluded that a good correlation in the morphometric dimensions of a human knee joint exists between the right and the left side. This study supports the concepts of obtaining morphometric reference data from the contralateral uninjured side in the evaluation of unilateral pathologies of the knee joint.

Purpose: The purpose of this study was to categorize and systematize the arterial supply of the metatarsal bones and furthermore the observation of arterial lesions after frequently performed forefoot surgeries., Materials and Methods: Twenty-two cadaver feet were analyzed by two plastination methods and the enzyme maceration method. Five forefoot surgeries were performed after arterial injections., Results: The bases of the metatarsal bones were primarily supplied by dorsal and plantar arteries. The arterial supply of the metatarsal diaphysis was given by a frequently observed nutrient artery. The first plantar metatarsal artery was the main supply of the first metatarsal head. The plantar and dorsal metatarsal arteries supplied the lesser metatarsals heads. The forefoot surgeries revealed lesions of arteries in all cases., Conclusions: The plastination methods were excellent methods to analyze the arterial supply. In addition arterial damage after forefoot surgeries could be analyzed with these methods.

Correct placement of the tibial and femoral bone tunnel is prerequisite to a successful anterior cruciate ligament (ACL) reconstruction. This study compares the resulting radiographic femoral bone tunnel position of two commonly used techniques for arthroscopically assisted drilling of the femoral bone tunnel: the transtibial approach or drilling through the anteromedial arthroscopy portal. The resulting bone tunnel position was assessed in postoperative knee radiographs of 70 patients after ACL reconstruction. Three independent observers identified the femoral bone tunnel and determined its position in the lateral and A-P view. Differences in femoral tunnel position between transtibial and anteromedial drilling were evaluated. In the sagittal plane, significantly more femoral bone tunnels were positioned close to the reference value using an anteromedial drilling technique (86%) when compared to transtibial drilling (57%). Drilling through the transtibial tunnel resulted in a significantly more anterior position of the femoral tunnel. In the frontal plane, femoral bone tunnels which were placed through the anteromedial arthroscopy portal displayed a significantly greater angulation towards the lateral condylar cortex (50.92 degrees ) when compared to transtibial drilling (58.82 degrees ). In conclusion, drilling the femoral tunnel through the anteromedial arthroscopy portal results in a radiographic femoral bone tunnel position which is suggested to allow stabilization of both anterior tibial translation and rotational instability when using a single bundle reconstruction technique. Further studies may evaluate if there are any clinical advantages using the anteromedial portal technique.

The purpose of this study was to develop a two-dimensional density distribution pattern of the subchondral cortical bone of the radial head using subtraction densitometry. The bone density of 32 normal specimens and five with macroscopic signs of osteoarthritis was measured before and after milling off the cortical bone surface. Electronic subtraction gave the density of the subchondral cortical bone. Twenty-one specimens had areas of high bone density in the ulnar-dorsal area, five specimens showed a ventral and ulnar density maximum and six had a density maximum in the center of the radial head joint surface. No density maximum was seen in the lateral part of the joint surface. The density maximum shifted towards the dorsal-ulnar part of the radial head with decreasing total subchondral bone density. Osteoarthritic radial heads had the same distribution as non-arthritic specimens. Eccentric subchondral bone density reflects eccentric radiohumeral force transmission. This could be a reason for development of radiohumeral arthritis or the failure of radial head prostheses. Bone density patterns correlate with the incidence of radial head fractures and fracture line may be positioned between areas of high and low densities.

Introduction: The purpose of this study was to describe the anatomy of the intramedullary canal of the radial neck for stem design of radial head prostheses., Methods: Radial neck measurement was performed from the proximal edge of the radial tuberosity to the distal border of the articular surface on 40 macerated proximal radii using X-rays and Optosil imprints of the intramedullary canal. Radial neck to shaft angle was measured under image intensification., Results: The neck length was 13.3 mm (range 8.0-20.0 mm) measured on X-rays and 13.5 mm (range 9.9-18.8 mm) on Optosil imprints. Concerning the neck's intramedullary canal we obtained a minimum diameter of 9.7 mm (range 6.3-16.4 mm) on X-ray. Corresponding Optosil imprints had a mean diameter of 11.6 mm (range 6.6-18.6 mm) at their proximal end, 10.5 mm (range 5.5-16.3 mm) in the middle and a minimum of 9.8 mm (range 6.0-16.9 mm) at the distal end. Differences between left and right sides were not significant between X-ray and Optosil imprints, nor between left X-ray and right imprints and vice versa at a P-level of 0.001. Radial neck to shaft angle was 167.8 degrees (range 160.5-178 degrees ) measured under image intensification at a rotation angle of 58.6 degrees (range 50-70 degrees ) supination., Conclusion: Geometry of the radial neck's intramedullary canal has been described for stem design. The minimum diameter was seen at the distal end, just proximal to the radial tuberosity. A forearm rotation of 58.6 degrees to full supination should be considered during implantation of monopolar prostheses. The wide variety of lengths and diameters complicates standard prosthetic design, but ipsilateral and contralateral X-rays can be useful for preoperative stem size calculation.

Introduction: Exact anatomical description of the proximal radius is imperative for the development of radial head prostheses. The purpose of this study was to measure the anatomical parameters of the radial head., Methods: Optosil imprints of 18 pairs of proximal radii fixed with formalin were taken. All possessed their native cartilage joint surface free of any arthritic defects. After being cut into 3 mm slices, the diameter of each slice was measured in steps of 30 degrees of rotation with the margo interosseous acting as a reference point., Results: Maximum radial head diameter was seen from the 0 to the 9 mm slice at a rotation of 30 degrees to full supination perpendicular to the proximal radioulnar joint. The diameter increased from the radiocapitular joint surface to the 6 mm slice, and then it decreased (P < 0.001). At the level of 6 mm the maximum radial head diameter was 24.13 mm (range 21.2-27.3 mm). The minimum diameter was seen perpendicular to the maximum; it also increased from the radiocapitular joint surface to the 6 mm slice and then decreased. There was a significant difference between the minimum and maximum diameter of each slice at a P-level of P < 0.001. Left and right sides were not significantly different at a P-level of 0.01., Conclusion: Our data show that the radial head is neither round nor conical. It has a complex shape with an increasing size from the radiocapitular joint surface to the middle of the proximal radioulnar joint surface. No statistically significant differences could be observed between right and left radii.

Objective: An experimental cadaver model was used to assess the effects of a malunited fracture of the middle third of the clavicle on the functional anatomy of the shoulder joint., Method: Anatomic samples were prepared with simulated shortening and axial malposition of the clavicle. From these, alterations in glenoid fossa position were measured and depicted graphically., Results: Healing of clavicle fractures with bony shortening leads to a ventromedialcaudal shift in glenoid fossa position. The following malpositions of the clavicle lead to the respective glenoid fossa positional changes: caudal deviation leads to a mediocaudal shift, cranial deviation leads to a dorsolateral shift of the glenoid fossa, ventral deviation causes a ventrolateral shift, dorsal deviation leads to mediocaudal shift of the fossa, cranial rotation leads to ventrolateral shift in fossa position, and caudal rotation leads to a dorsomedial shift in glenoid fossa position., Conclusion: Clinical implication of these data is that bony shortening in combination with caudal displacement leads to distinct functional deficits in abduction, particularly overhead motion. Using the above data, a vector model was created to calculate position of the glenoid fossa dependent on clavicle position/malposition. The model is a valuable tool to be used for planning open reduction and fixation of clavicular fractures or malunions.

Graft placement in cruciate ligament reconstruction is known to significantly influence postoperative knee stability and range of motion. Improvement of bone tunnel positioning has been advocated by computer-assisted surgical procedures that require reliable input and reference data. This study validates the hypothesis that morphometric reference data can be obtained from the uninjured controlateral knee for accurate bone tunnel and graft positioning. Thirty pairs of human cadaver knees were dissected and the femoral and tibial footprints of the anterior and posterior cruciate ligaments (PCL) were radiopaquely marked. Radiographs were taken of the corresponding left- and right-sided femora and tibiae, and digitally processed. Controlateral specimens were mirrored and overlapped precisely, the areas and intersections of ligament insertion were digitally determined. There were no significant differences in the total area of cruciate ligament insertion between left and right knee specimens or between female and male specimens. Intersection areas (IAs) in femoral and tibial anterior cruciate ligament (ACL) insertions averaged 31.3 and 33.4% of the total insertion area, respectively. The center of gravity for the femoral and tibial ACL footprint differed by 4.7 and 4.5 mm between left and right knees, respectively. IAs in femoral and tibial PCL insertions averaged 46.1 and 61.3% of the total insertion area, respectively. The center of gravity for the femoral and tibial PCL footprint differed by 4.5 and 2.4 mm between left and right knees, respectively. Our study does not support the concept of obtaining morphologic reference data from the uninjured controlateral knee for individual bone tunnel placement.

The first tarsometatarsal (TMT) joint has a complex role in regulating joint pressure in the midfoot. Despite its importance, there have been only a few studies of the functional morphology and biomechanical function of this joint. Here we report about the densitometric pattern of the subchondral bone layer of the articulating elements of the human first TMT joint. We studied dry bones of the first metatarsal and medial cuneiform bones in 64 human cadavers to establish the pattern of the density distribution and to correlate it with the biomechanical function of the joint. The articular surfaces of both the bones were analyzed planimetrically. Half of the specimens (n=32) were sectioned in the sagittal plane and the other 32 articulations were in the transverse plane. In all the sections, the subchondral bone density of the first TMT joint was measured. We found that in sagittal slices the dorsal area of the lateral parts and intermediate parts in females and the dorsal area of the lateral parts, the medial parts and intermediate parts in males were denser than the plantar area and that its density decreased towards the plantar area. The dorsal parts of transverse slices in males were the densest and its density decreased towards the plantar part. In the dorsal, middle and plantar parts in females in transverse slices, the lateral and intermediate areas were denser than the medial areas (P<0.05). There was no significant difference between the bone densities of females and males.

The present study was conducted to evaluate the influence of bone-plug length on the primary stability of patellar tendon-bone grafts, using a femoral press-fit fixation technique. Forty-eight human PTB grafts with a patellar bone-plug length of 15 mm and 25 mm were obtained from 24 human cadavers (mean age 72 years) and implanted to porcine femora in a press-fit fixation technique. Tensile loading was performed at 10 mm/s until failure at varying loading angles of 0 degrees, 30 degrees and 60 degrees. Compared to 25 mm, a significant decrease of primary graft stability was recorded in the testing of 15-mm bone plugs. For both plug lengths, the ultimate load to failure increased with rising the loading angles. While axial graft loading exclusively caused plug dislocation, the predominant mode of failure was tendon rupture at 60 degrees loading angle. We conclude that 15-mm bone plugs do not result in a sufficient stability for early aggressive rehabilitation and therefore 25-mm bone plugs are recommended for the femoral press-fit technique.

Bone vascularisation has gained increased interest in relation to the blood supply of bone fragments during treatment of fractures. In the current study the pattern of vascular supply of the proximal humerus was studied in six cadavers by the corrosion technique. Furthermore, the effect of fractures on the vascular supply was also investigated. In all preparations the intraosseous arteries of the humeral head arose from the circumflex arteries, which surrounded the humerus and dispatched branches towards the proximal end. The main vessel was the branch of the anterior circumflex artery, penetrating the major tubercle in six of six cases. Due to the intraosseous arch shape of this vessel it is referred to as the arcuate artery. Besides other smaller vessels, there was also a vascular network arising from the posterior circumflex artery. Their branches penetrated medially at the cartilage bone interface in five of six preparations. The medial bone arteries appear to gain distinctive importance in humeral head fractures by their impact on the vascularisation of the fracture fragments. After disruption of the arterial supply from the arcuate artery, the vascularisation of the head fragments is most likely ensured by this group of vessels. Therefore, necessary repositioning manoeuvres during open reduction of the fracture should be conducted with care in order to preserve these arteries.

We described the anatomy of the utero-ovarian venous system in the adult postmenopausal female cadaver using casts and the von Hagen's plastination technique. To qualitatively and quantitatively evaluate the uterine vein, the utero-ovarian arcade, the ovarian vein and the ramus communicans between left and right parametrium, we injected epoxy resin into the internal iliac vein and artery and the ovarian vein and artery in six cadavers. In two cases the internal genital organs were excised before injection and in the other four after the injection and polymerization of the resin. All specimens were macroscopically examined and venous diameters were digitally measured, the average values of the measured diameters being 3.38 mm for the uterine vein, 3.71 mm for the utero-ovarian arcade, 3.49 mm for the ovarian vein, and 3.71 mm for the ramus communicans. The veins were completely filled out and could be best examined in the four cases where in situ injection was performed. We could observe that the utero-ovarian arcade is an important vein with a caliber similar to that of the ovarian and uterine veins, that there is an impressive network of venous anastomoses between the left and right parametrium and that the fallopian tubes are drained by three separate veins: internal, median, and external tubal veins. Pelvic venous congestion was present in two specimens; in one of them it was located in the region of the left uterine vein and in the other one in the region of the left ovarian vein. Given the similar average diameters of the uterine vein, ovarian vein, and utero-ovarian arcade, we assume that there is no preferential uterine or ovarian venous drainage and that the veins of the internal genital organs are behaving like a venous pool. Nevertheless, congestion can affect limited sites, which can and should be treated locally.

An anatomic study of the lateral extraosseous and intraosseous arterial supply of the calcaneus and the lateral soft tissue was carried out on 10 fresh lower adult cadaver legs using different anatomic and radiologic procedures (plastination, modified Spalteholz clearing technique, digital subtraction and rotational angiography and computed tomographic angiography). Consistent patterns of extraosseous and intraosseous lateral calcaneal vascular anatomy were demonstrated. The lateral calcaneal artery is a branch of the anterior tibial artery which crosses over the calcaneal tuberosity and forms a large lateral arch with the lateral tarsal artery which is a branch of the dorsalis pedis artery. The intraosseous circulation is supplied laterally by the lateral calcanear artery, medially via the short branches of the lateral plantar artery. Comparing magnet resonance images after fresh calcaneal fractures the lateral calcanear artery may be interrupted by the impacted lateral bulge, by the conventional lateral surgical approach, or by applying a lateral osteosynthesis plate. This may cause avascular bone necrosis. Furthermore the lateral calcanear artery can clinically serve as a vascular pedicle for a local rotational skin flap to cover soft tissue defects of the heel.

The metacarpophalangeal (MCP) joints II to V of 21 hands were examined radiologically and arthrographically. Different recesses of the joint cavity were demonstrated both radiologically and macroscopically, with a dominating dorsal recess. The existing forms of the dorsal recess were one-tailed, two-tailed, three-tailed, symmetric and cap-like. Additionally, a palmar recess was found in the specimens examined, which presented as a small protrusion of the capsule and lay between the metacarpal head and the palmar plate. Furthermore, a distal recess was filled and unfolded in almost all the cases. Lateral recesses were found in the radial and ulnar directions beneath the collateral ligaments. The dorsal recess, due to its ability to collect fluid, is of clinical importance in pathologic processes causing effusions, while the clinical importance of the lateral recesses lie in their proximity to the stabilizing collateral ligaments of the metacarpophalangeal joints. The above mentioned recesses were seen as normal formations of the MCP joints and should therefore be taken into account in pathologic processes in this area.

The operative exposure of a fracture in an osteosynthesis causes disturbances in the blood supply, which often leads to a prolonged process of healing or even to healing problems, a fracture non-union, which is frequently located at the forearm. In order to damage the supplying vessels as little as possible, the position, direction and penetration of the arteries of radius and ulna are demonstrated and systematised in this study. Near the elbow arteries, coming from large adjoining vessels, penetrate the area of the capsular insertion. The nutrient arteries enter both bones in the second proximal quarter of diaphysis, at the radius from anterior to medial, at the ulna from anterior to anteroradial. Small vessels, which penetrate closely proximal to the articular surface in order to supply the distal forearm bones, come from an anastomosis between the radial, the interosseous and the ulnar arteries. In this study access vessels, choice and position of implants will be discussed.

The operative exposure of a fracture causes disturbances in the blood supply, which may lead to a prolonged healing process or even to bone necrosis, especially when using the complex and complicated methods of osteosynthesis at the ankle. In order to damage the supplying vessels as little as possible, position, direction and penetration of the bone arteries of the talocrural joint were examined by corrosion preparation. The tibial nutrient artery arises from the posterior tibial artery or from the popliteal artery and penetrates constantly from posterior at the level of the proximal third. The fibular nutrient artery, coming from the peroneal artery, penetrates more distally from medial into the middle third of the diaphysis. In one specimen it did not exist at all. Distal tibia and fibula are supplied by the perimalleolar arterial ring, which is connected with the three arteries of the leg. The talus is supplied by numerous very small vessels, which are provided with extraosseous anastomoses and penetrate the whole non-articular surface. Implications for the operation will be explained.

In the present study saddle joints of the thumb and neighboring joints of 100 anatomic specimens are examined with regard to radiological and macroscopic arthrotic alterations. Comparisons of radiological and macroscopic findings demonstrate that early arthrotic articular alterations cannot be diagnosed radiologically. Almost half of the hands examined displayed arthrotic lesions in the saddle joint of the thumb, whereas the trapezoido-scaphoidal and trapezio-scaphoidal joints are each affected in one third. Hands with manifest thumb saddle joint arthrosis are accompanied by arthrotic alterations of the joints between the scaphoid, trapezium and trapezoid in two-thirds of the cases. In the remaining radial intercarpal joints, no macroscopic evidence can be ascertained of arthrotic alterations. Among the processes discussed as causal factors of simultaneous incidence of scaphoidal and carpo-metacarpal arthroses, the architecture of the osseous carpus, the individual expression of the scaphoid bone and poly- or secondary arthrotic processes are important.

Although the clinical and functional importance of gliding and connective tissue spaces has been repeatedly emphasized (e.g. their role in the spreading of suppurative phlegmonic inflammation) only few literary findings can be presented dealing with the connective tissue spaces in the finger in the metacarpo-phalangeal transition region. Three separate gliding spaces of the finger above the dorsal aponeurosis and their various regional connections can be displayed by means of a plastic injection technique followed by plastination and production of sectional series. These gliding spaces were also examined on fixed and unfixed hands using plastic injection and subsequent dissection. A space was depicted between the proximal interphalangeal joint and the insertion of the dorsal aponeurosis on the distal phalanx of the finger, as well as a further bursa-like space over the proximal interphalangeal joint. A third space was also depicted between the metacarpophalangeal joint and the proximal interphalangeal joint, which displays a variable connection to the gliding canal of the respective extensor tendons. Methodical, functional and clinical aspects will be discussed.

Radiographs are used in a wide variety of musculoskeletal examinations. Special procedures are required to improve image quality. We report a new radiologic technique that uses monochromatic molybdenum K alpha-radiation together with secondary digital color-coding to produce well contrasted images of supporting tissue. In order to investigate the diagnostic capability of this approach we studied specimens of the intervertebral disc, harvested from cadavers undergoing chemonucleolysis following an injection of chymopapain. Radiographs of the specimen taken using a Mo X-ray tube with a zirconium filter were scanned into a computerised image-processing system and color-coded. This method improves resolution and contrast in the images and allows the differentiation of morphologic changes.

Repair of meniscal tears occurs best in the region of the capsular attachment. The further the tear from the site of capsular attachment, the less the vascularity, and healing becomes dubious. For an evaluation of healing in the poorly vascularised zone of the meniscus a histological study was performed in rabbits with standard longitudinal incisions in the posterior horn of the left medial menisci. In addition a biomechanical investigation of scar strength was performed. Three groups of animals were studied: group 1 were allowed to heal spontaneously, group 2 were sutured and group 3 were treated with fibrin glue. After 6 weeks, macroscopically, 4 out of the 10 menisci in groups 1 and 3 exhibited incomplete scar formation, whereas all menisci in group 2 looked well. This result fell short of statistical significance because 2 menisci in group 2 had to be excluded due to faulty localisation of the standard injury. In all groups the scars contained fundamental elements of healing, such as fibroblasts, blood vessels and fibrous material. Repair seemed to be significantly influenced by the proliferating synovial membrane. Histologically there was no difference between group 1 and 3. In both groups the lesions were filled with a broad strip of reparative tissue mostly consisting of plexiform collagenous fibres. Although the appearance of the menisci in group 2 was similar, the scar tissue was distinctly thinner due to the close adaptation of the wound margins, and the vascularity seemed better. In all specimens the tissue located towards the free rim of the meniscus showed signs of degeneration.(ABSTRACT TRUNCATED AT 250 WORDS)

The knowledge of weak points in the osseous structure of the skull is of great importance for endonasal operations. For this reason the anatomy of the skull is accurately described in serial sections. Serial sections of 1.5 mm thickness are evaluated by a computerized image analyzing system, which allows qualitative as well as quantitative statements on the structure of the paranasal sinuses and their neighbourhood. The bone density in the frontobasal area of the skull as well as of the ethmoid cells is presented separately. The anatomy of the sphenoid sinus is described by densitometric and gross techniques.

Anatomic characteristics of the lunate, the pisiform and the capitate were compared in order to support the use of a pisiform transplant or the intercarpal fusion by Graner in advanced stages of Kienböck's disease. Fifty lunate and pisiform bone pairs and 20 wrist specimens served for morphological and functional investigations. In view of the present results, the pisiform, after a rotation of 90 degrees, should be implanted in the lunate box with its longitudinal diameter oriented to the dorsopalmar plane. Despite the small pisiform volume, maintainance of carpal height is assured by its relatively large dorsopalmar diameter. The rotated position permits use of existing soft tissue structures and improves the conditions of force transmission. Measurements comparing the radii of curvature of the original lunate and the substitute pisiform surfaces show a good correspondence proximally and a reduction of the articular congruity distally, due to the flatness of the pisiform surface. The palmar convexity of the pisiform adapts better to the distal radius facet than the capitate head, which replaces the lunate in Graner's surgical procedure.