Computer tomography aided 3D analysis of the distal dorsal radius surface and the effects on volar plate osteosynthesis.

The aims of this study were to measure the size of Lister's Tubercle, the extent of the extensor pollicis longus (EPL) groove and the dihedral angle of the distal dorsal radius. Computer tomography scans of 30 forearms were performed by using a 64-slice Siemens SOMATOM Sensation CT system (Resolution 0.6 mm). DICOM raw data were calculated to 3D by MIMICS software (Materialise, Leuven, Belgium). The size of Lister's Tubercle varied from 1.4 to 6.6 mm (average 3.3 mm) in height radial to the tubercle, and from 5.6 to 18.6 mm (average 13.2 mm) in length. The depth of the EPL groove varied from 0.6 to 3.2 mm (average 1.6 mm). The height on the ulnar side, between the depth of the groove and the tip of the tubercle, varied from 2.2 to 5.8 mm (average 3.4 mm). The dihedral angle of the distal dorsal radius varied from 110 degrees to 135 degrees (average 123 degrees). The variations in height of Lister's Tubercle and in depth of the EPL groove are considerable. This needs to be taken into account when performing volar plating of distal radius fractures otherwise screws may inadvertently penetrate the dorsal cortex of the radius potentially leading to EPL rupture.

Perforation of the third extensor compartment by the drill bit during palmar plating of the distal radius.

The frequency of penetration into the third extensor compartment when drilling the distal screw holes was assessed for four different palmar distal radius plates in 160 cadaver forearms. Penetration into this compartment occurred in 43%. Different plates had different penetration rates: 3.5 LCP four-hole locking T-plate: 20%, 3.5 LCP three-hole locking plate: 42.5%, 2.4 palmar LCP standard plate and the 2.4 palmar LCP buttress plate: 55%. When using a palmar plate on the distal radius, the surgeon risks penetrating into the third extensor compartment.

Promontory of radius: a new anatomical description on the distal radius.

Surgical treatment of distal radius fractures with palmar plates has gained popularity as the preferred approach to achieve anatomical fracture reposition. One hundred and thirty four radii of human cadavers were examined to elucidate the anatomy of the distal radius, especially the transition of the anterior into the lateral surface and a new term was given: promontory of radius. The promontory was located on the lateral surface between the changing of the convex to the concave curvature and the base of the styloid process. The anterior surface increased gradually from the ulnar notch to the lateral surface and formed the "base" of the promontory. The length of the promontory on the lateral surface measured 14-28 mm (mean 20.766 mm, SD 2.69 mm). The width of the promontory was found in between 10 and 27 mm (mean 13.857 mm, SD 2.14 mm). The width of the distal radius was 16-38 mm (mean 31.015 mm, SD 3.26 mm) and did not show any statistical correlation to the promontory. On the anterior surface the minimal width of promontory measured 4.9 mm, the maximal one 17.9 mm (mean 8.95 mm, SD 3.60). The height of the promontory on the anterior surface ranged in between 1.2 and 4.3 mm (mean 2.90 mm, SD 1.05 mm). The promontory of radius must be kept in mind to avoid any dorsal dislocation of the radial fragment often described as complication of intraarticular fractures. Based on this anatomical survey the data can be used for a new palmar radius plate designs.

The influence of lateral and anterior angulation of the proximal ulna on the treatment of a Monteggia fracture: an anatomical cadaver study.

We have investigated the anatomy of the proximal part of the ulna to assess its influence on the use of plates in the management of fractures at this site. We examined 54 specimens from cadavers. The mean varus angulation in the proximal third was 17.5 degrees (11 degrees to 23 degrees ) and the mean anterior deviation 4.5 degrees (1 degrees to 14 degrees ). These variations must be considered when applying plates to the dorsal surface of the ulna for Monteggia-type fractures. A pre-operative radiograph of the contralateral elbow may also be of value.

Additional muscle in idiopathic club foot.

During the dissection of seven club feet of foetuses, aborted between the 25th and 37th week of gestation, an additional muscle bundle was found in a right foot. This muscle arose from both heads of the gastrocnemius muscle, continued downwards onto the posterior surface of the soleus, crossed the calcaneal tendon and assumed a position on the lateral side of the calcaneal tendon. The muscle's tendon was fixed just laterally to the calcaneal tendon in the calcaneal tuberosity with some tiny fibres branching off into the superior fibular retinaculum.

Subtle cognitive dysfunction in adult onset myotonic dystrophy type 1 (DM1) and type 2 (DM2).

The authors performed neuropsychological testing in 21 patients with myotonic dystrophy type 1 (DM1) and 21 with type 2 (DM2) and healthy controls. They detected no general cognitive deficit in either DM1 or DM2, but compared to controls, both groups of patients were inferior in tests of prefrontal functioning. Patient groups did not differ in any measure. Mood status was not related to neuropsychological performance. This is consistent with findings of executive dysfunction in both DM1 and DM2.

Capsular attachment to the distal radius for extracapsular placement of pins.

The aim of this study was to evaluate the anatomy of the wrist joint capsule on the distal radius. As such the extent of the joint capsule and the limits of attachment in relation to the articular surface were determined. Furthermore, the study also determined whether there was any reflection of the capsule onto the distal radius. Fifty cadaveric specimens, preserved according to Thiel's method, were assessed. After careful dissection the distance between the chondral line of the carpal articular surface and three defined points on each of the palmar and dorsal aspects of the radius were measured. In none of the specimens was there any variation in the course and extent of the joint capsule. Using external fixators for managing fractures of the distal radius, pins and wires can be placed subchondrally close to the articular capsule. The risk of intraarticular infection, due to pin tract infection in intraarticularly positioned pins, is very low.

[The distal radius and surrounding soft tissues--ultrasound anatomy and ultrasound pathology in the adult and child]. / Der distale Radius und seine umgebenden Weichteile--Sonoanatomie und Sonopathologie beim Erwachsenen und beim Kind.

BACKGROUND: The aim of the study was to evaluate the ultrasonographic anatomy of the distal forearm (i.e. distal radius and surrounding soft tissue) and the typical changes occurring during growth, in adults and children. MATERIAL AND METHODS: The ultrasonographic anatomy was evaluated in 10 healthy adults aged between 20 and 60 years, and 20 healthy children aged between 2 and 18 years. Particular attention was paid to dynamic examination comparing both limbs, and isolated investigations of functional tendon. RESULTS: An anatomical description of the tissues of the distal forearm was possible at all ages. During growth, secondary ossification centres and the transitional osteochondral region of the growth plate need particular consideration. DISCUSSION AND CONCLUSION: Both in children and adults, ultrasonography can provide valuable information in the evaluation of acute trauma, follow-up of fractures and osteosynthesis, suspected osteomyelitis and chronic disorders. In children, special attention must be paid to the development of the epiphyseal region, as reflected by ossification centre, growth plate and articular cartilage.

The fourth lumbrical muscle in the hand: a variation of insertion on the fifth finger.

Usually the four lumbrical muscles arise from the tendons of flexor digitorum profundus and insert into the extensor expansions on the radial side of the corresponding fingers. This special case showed a very rare variation of a unipennate fourth lumbrical muscle of the right hand; the muscle fibre bundles originated on the radial side of the flexor digitorum profundus and coursed horizontal on its radial side, deep to the palmar aponeurosis and in front of the deep transverse metacarpal ligament over the fifth metacarpophalangeal joint. At the level of this joint, its tendon divided into one radial and one ulnar slips. Both heads surrounded the tendons of the flexor digitorum superficialis and profundus muscles, and found their insertion into the flexor digitorum superficialis tendon, as well as their bony attachment into the proximal and even more into the middle phalanx.