1. Bryce, T. H.: On Certain Points in the Anatomy and Mechanism of the Wrist-Joint Reviewed in the Light of a Series of Roentgen Ray Photographs of the Living Hand, J. Anat. Physiol. 31, 59-79, 1896. 2. Arkless, R: Cineradiography in Normal and Abnormal Wrist, Am. J. Radiol. 96, 837-844, 1966. 3. Youm, Y.: Kinematics of the Wrist, J. Bone Joint Surg. 60A, 423-431, 1978. 4. Hall, M. C.: Architecture of Bone, Charles C. Thomas Publisher, Springfield, Illinois, 1966. 5. Speed, K.: Fractures and Dislocations of the Carpus, California Med, 72, 93-98, 1950. 6. Campbell, R. C., Lance, E. M. and Yeoh, C. B.: Lunate and Perilunar Dislocation, J. Bone Joint Surg. 46-B, 55-72, 1964. 7. Hayden, J. W.: Median neuropathy in the carpal tunnel caused by spontaneous intraneural hemor rhage, J. Bone joint Surg. 46-A, 1242-1244, 1964. 8. Blunt, M. J.: The Vascular Anatomy of the Median Nerve in the Forearm and Hand, J. Anat. 93, 15-22, 1959. 9. Tanzer, R. C.: The carpal tunnel syndrome, J. Bone Joint Surg. 41-A, 626-634, 1959. 10. Robbins, H.: Anatomical study of the median nerve in the carpal tunnel and etiologies of the carpal tunnel syndrome, J. Bone Joint Surg. 45-A, 953-966, 1963. 11. Nissen, K. I.: Etiology of carpal tunnel compression of the median nerve, J. Bone Joint Surg. 34-B, 514-515, 1952. 12. Engel, J., Zinneman, H., Tsur, H. and Farin, I.: Carpal tunnel syndrome due to carpal osteophyte, The Hand 10, 283-284, 1978. 14. Johnston, H. M.: Varying Positions of the carpal bones in the different movements at the wrist, J. Anat. Physiol. 41, 109-122, 1907. 15. Chiu, L. C. and Schapiro, R. L.: Atlas of computed body tomography, University Park Press, Balti more, 1980. 16. Landsmeer, J. M. F.: Atlas of Anatomy of the Hand, Churchill Livingstone, Edinburgh, London and New York, 1976. 17. Kaplan, E. B.: Functional and Surgical Anatomy of the Hand, 2nd Edition, J. B. Lippincott Co., Phi ladelphia and Montreal, 1965. 18. Dekel, S., Papaioannou, T., Rushworth, G. and Coates, R.: Idiopathic carpal tunnel syndrome caused by carpal stenosis, Br. Med. J. 31, 1297-1299, 1980.

19. Kauer, J. M. G.: Functional anatomy of the wrist, Clin. Orthop. 149, 9-20, 1980. 20. Trieppel, H.: Die Architektur der Knochenspongiosa in neuer Auffassung, Zschr. F. Konstitution slehre 8, 269-311, 1922. 21. Wolff, J.: Uber die Bedeutung der Architektur der spongidsen Substanz fur die Frage vom Kno chenwachstum, Cbl. med. Wiss. 7, 849-851, 1869.

Study on the Transverse Osseous Architecture of the Carpal Region Mitsunobu KOUNO The Department of Orthopedic Surgery, Okayama University Medical School Key word: sulcus carpi, osseous architecture, microradiography In order to study the transverse osseous architecture of the carpal region, eight wrist hand specimens were obtained from four cadavers. The specimens were embedded in pol yester resin after the soft tissues had been removed completely. The embedded specimens were cut into serial sections. The cutting was carried out perpendicular to the longi tudinal axis of the third metacarpal bone. Each section was examined by microradio graphy. The shape of the bones, the width and the area of the carpal sulcus as well as the trabecular architecture were studied. The results were summarized as follows: 1. The bone shapes were divided into six groups, i.e. radio-ulnar joint level, proximal level of carpals, intermediate level of carpals, distal level of carpals, the first CM joint level and the metacarpal base level. The carpal sulcus corresponded to the intermediate, distal carpal level and to the first CM joint level. 2. Prominence of a volar arch of the carpal sulcus was observed not at the center of the arch but at the ulnar side. This prominence shifted more to the ulnar side in the distal level of carpals than in the proximal level. From these findings it was considered that the prominence of the volar arch functioned as a pulley for the flexor tendons of fingers in grasping. 3. Although the width of the carpal sulcus became narrower towards the distal level of the carpals, the largest area was obserbed at the distal level. From these observa tions, the cause of the carpal tunnel syndrome was considered to be an imbalance between the volume of the carpal tunnel and its contents such as flexor tendons and nerves. 4. The articulations of carpal bones indicated that the motion center of the carpal bones was situated at the head of the capitate. 5. The trabecular orientation was divided into three groups: trabeculae perpendicular to the joint surface, trabeculae crossing each other at right angles which were observed at radial and ulnar prominences of the carpal sulcus, and trabeculae arranged without interruption through the arch of the carpal sulcus.