I. Ohshio

Correlation between histopathologic features and magnetic resonance images of spinal cord lesions.

The authors report a correlation between histopathologic features and magnetic resonance images of spinal cord lesions in 19 human spinal cords with various types of lesions. Abnormally high T2-weighted image signal intensities appeared nonspecifically in mildly altered lesions or areas with edema. In the gray matter, a low T1-weighted image in addition to a high T2-weighted image signal intensity appeared in severely altered lesions with necrosis, myelomalacia, or spongiform change. In the white matter, abnormally high T1-weighted image intensities appeared in severely altered lesions. Based on these preliminary results, it appears that a correlation between the degree of histopathologic alteration of the spinal cord and magnetic resonance images in clinical cases can be made. This is the first study to clarify the correlation between histopathologic features and magnetic resonance images of the diseased human spinal cord.

Correlation between clinical results and carpal instabilities in patients after reduction of lunate and perilunar dislocations

Thirteen patients with lunate and perilunar dislocations were treated in our department in the last five years. Ten out of the thirteen patients were followed more than eight months with an average of two years and two months. Two out of the ten patients followed failed to obtain normal anatomical carpal architecture. These two patients were treated by arthrodesis of the wrist and proximal row carpectomy, respectively. The remaining eight patients, that obtained reduction, were classified into three groups according to existence of gap between the scaphoid and lunate, and incongruity between the lunate and triquetrum. Patients with a gap between the scaphoid and lunate of more than 3 millimetres after reduction of their dislocations had poor clinical results. This suggests significant correlation between clinical results and carpal instabilities.

Experimental study of radial ray deficiency

The teratogenic mechanisms of radial ray deficiency were investigated. Radial ray deficiencies were induced in WKAH/Hkm rat foetuses by maternal administration of myleran on day 10, 10.5, or 11 of pregnancy. The skeletal anomalies in rats were similar to those in human beings, suggesting that exposure to some environmental factors at a sensitive period of embryogenesis may cause radial ray deficiency in humans. Ulnar ray deficiency has also been induced in rat foetuses by maternal administration of myleran, so it is suggested that radial deficiency and ulnar deficiency are caused by a common teratogenic mechanism in humans. However, the critical period for radial deficiency is one day later than that for ulnar deficiency in rats, which may contribute to the greater frequency of radial deficiency than ulnar deficiency in clinical cases.

Extensor tendon rupture due to osteoarthritis of the distal radio-ulnar joint

Five cases of closed rupture of the finger extensor tendon due to osteoarthritis of the distal radioulnar joint were studied. Difficulty in extension began at the little finger and extended to the ring and long fingers. Pain and swelling in the dorsal aspect of the wrist preceded the tendon rupture. Osteoarthritic changes at the distal radio-ulnar joint were more severe than those at the radio-carpal and intercarpal joints. The distal end of the ulna showed the plus variant, as well as dorsal dislocation or subluxation. All patients underwent a tendon graft or tendon transfer, with excision of the distal ulna. The tendon rupture was thought to be caused mainly by friction between the displaced distal end of the ulna and osteophytes of the distal radio-ulnar joint.

Tumourous deposition of calcium pyrophosphate dihydrate crystals in the wrist: A case report

A 63-year-old man had a tumourous deposition of calcium pyrophosphate dihydrate crystals in the palmar aspect of the wrist. Traumatic micro-fracture or osteoarthritis was thought to have triggered the deposition of these crystals. It should be possible to differentiate the lesion clinically and radiologically from tumoural calcinosis, in which the deposits consist of calcium carbonate and/or calcium phosphate.

Dislocation of the hamate associated with fracture of the trapezial ridge

A case of dislocation of the hamate bone, associated with palmar ridge fracture of the trapezium, is described. The mechanism of this injury is thought to be traction force through the transverse carpal ligament caused by a flattening of the transverse carpal arch.

Reconstruction of the central slip by the transverse retinacular ligament for boutonnière deformity

A method of repair of boutonnière deformity is described, using the transverse retinacular ligament. Six fingers in five patients were treated by this procedure. The deformity was improved in all fingers; complete or almost complete correction was obtained in four fingers and incomplete correction in two. However, severe limitation of flexion of the D.I.P. joint appeared in two fingers after surgery. This procedure is not indicated for boutonnière deformities with severe contracture of the lateral band; its best indication is in cases in which the central slip is defective and conservative treatment is not effective.

Investigation of DNA Synthesis and Cell Condensation in the Developing Rat Hand Plate by the BrdU/anti‐BrdU Technique

Abstract: DNA synthesis and cell condensation in the developing hand plate of the rat were examined by a BrdU/anti‐BrdU immunohistochemical study. DNA‐synthesizing cells were distributed uniformly in the mesenchyme of the hands until day 12.5 in rat embryos. From day 13.0, these cells were distributed in the interdigital mesenchymal areas, leaving rare labeled cells in sites of cell condensation (i.e., in the digital rays). After day 14.5, DNA‐synthesizing cells were confined to the interdigital areas near the digital rays. On day 15.0, DNA‐synthesizing cells appeared in the areas of joint formation. In the epidermis. DNA‐synthesizing cells were uniformly found in the period of digital‐ray formation. When the mesenchymal cells labeled on day 12.0 were followed from day 12.5 until day 14.0 of embryogenesis, they were found to become concentrated in the digital rays. From these findings, we conclude that the cells which are synthesizing DNA and actively dividing in the mesenchyme at day 12.0 migrate to the digital rays, where they undergo cell condensation. The experimental models and techniques employed in this study will be useful for investigations of normal development as well as teratogenesis of the extremities.

Clinical Features of Congenital Contractural Arachnodactyly

ABSTRACT Clinical features of 11 cases of congenital contractural arachnodactyly (CCA) were reported. Eight cases were male and 3 cases were female. Family history was positive in 6 cases of 3 families. As for hand deformity, flexion of the finger, adduction of the thumb and shortening of the palmar skin were observed in all cases, arachnodactyly in ten cases, flexion contracture of the finger joint in 6 cases. Dolichostenomelia and crumpled ear deformity were associated in all cases, spinal deformity in 6 cases, flexion contracture of the lower extremities in 5 cases, micrognathia in 2 cases and high palate, strabismus, pectus excavatum and polydactyly of the fifth toe in one case. Arachnodactyly was not an essential feature of CCA. Existence of multiple camptodactyly with or without arachnodactyly and/or ulnar drift of the fingers, and crumpled ear deformity were important findings for differential diagnosis of CCA. There was no association of cardiovascular anomalies in this series. CCA without ocular and cardiovascular involvement must be a definite clinical entity and should be distinguished from the other forms of marfanoid habitus.