Fractures of the triquetrum

Abstract

THE concentration of attention on the navicular has caused the other bones of the wrist to be neglected. We would like to rectify this in the case of the triquetrum, and emphasize the fact that fracture of this bone is commonly misdiagnosed as fracture of the posterior pole of the lunate. Bohler, quoting Schnek's statistics, first brought this latter diagnosis into prominence. In our opinion he exaggerated its frequency, isolated fracture of the posterior pole of the lunate being very rare, and only seen by us twice in a series of over a thousand wrist injuries. ANATOMYThe triquetrum is exceptional in having no part in the radiocarpal joint, but in taking part in the midcarpal joint, and moving freely with the lunate. This degree of mobility of the FIG. z4z.-Wrist in ulnar deviation, showing the possibilities of compression of the triquetrum.triquetrum is accomplished by leaving a space between the proximal pole of the triquetrum and the triangular fibrocartilage passing from the base of the styloid process of the ulna to the radius, and this space is filled with loose areolar tissue. Though there is thus no joint or bursa on the distal side of the fibrocartilage, the effect is the same. The triquetrum, roughly pyramidal in shape, inserts its sharpest angle between the lunate and the hamate; this wedge insertion would produce a tendency to extrusion of the bone in falls on the extended hand, if this weakness were not counteracted by the fact that in falls on the extended hand the wrist moves into ulnar deviation, and the triquetrum swings more deeply AND W. I?. GREENING into the wrist under cover of the lower end of the ulna (Fig. 242).Inspection of the volar surface of the bone shows the facet for the pisiform to lie at the apex of this surface, and thus a quadrangular surface is left between it and the edge of the articular surface for the lunate for the attachment of the volar intercarpal ligaments. Of the three remaining surfaces two are completely articular, for the lunate and hamate, and the third, which looks dorsomedially, corresponds to the double curved surface of the proximal row of carpal bones. It is marked by a groove, visible in most anteroposterior views of the wrist though not infrequently overlain by the shadow of the pisiform. Of the two areas thus delineated the smaller lateral area is for the attachment of the ulnar collateral ligament of the wrist, and forms a marked colliculus corresponding to the tuberosity of the navicular on the other side of the wrist. The larger and more medial area is again subdivided by a fainter line, the proximal facet being smooth and in contact with the areolar tissue previously mentioned. Owing to the curve of this surface of the bone, the distal facet comes to lie more on the dorsum of the wrist, and forms the posterior tubercle serving for the attachment of the dorsal intercarpal ligaments, which radiate from it in four directions, two ligaments branching FIG. z43.-Fracture of the radial corner of the triquetrum, from impact against the radius.proximally to th...

Trans-scaphoid mid-carpal dislocation associated with radial styloid fracture: A rare injury

“…3 Bonin and Greening described a fracture of the triquetrum in association with a perilunate dislocation and a fracture of the proximal pole of the scaphoid. 1 Weseley and Barenfeld described a case of trans-scaphoid, trans-capitate, trans-triquetral perilunate fracture dislocation of the wrist. 17 Both closed and open reduction of fracture dislocations of the carpal bones have been practiced in the past.…”

Isolated Triquetrum Fractures: The Importance of Proper Roentgenograms in Ulnar Sided Wrist Pain

“…First, it was accepted that body fractures occurred with compression mechanism and dorsal chip fractures occurred with avulsion mechanism [2] [3], but afterwards it had been suggested that dorsal chip fracture of the triquetrum was caused by the effect of ulnar styloid [1] [4] or the hamate [5] on the dorsum of the os triquetrum upon a fall on the wrist in dorsiflexion.…”

“…Wrist injuries occurring after a fall on the wrist account for an important portion of daily clinical practice of orthopedics. Although triquetrum fractures causing ulnar-sided wrist pain are the second most common carpal fractures after scaphoid, they are less common seen in daily clinical practice [2] [4] [5]. Most of these fractures are seen after a fall on an outstretched hand and they clinically manifest with painful and edematous wrist and limitation in movement [2] [6].…”

“…Although triquetrum fractures causing ulnar-sided wrist pain are the second most common carpal fractures after scaphoid, they are less common seen in daily clinical practice [2] [4] [5]. Most of these fractures are seen after a fall on an outstretched hand and they clinically manifest with painful and edematous wrist and limitation in movement [2] [6]. While localization of the pain to the ulnar side of the wrist is guiding for diagnosis, it should be kept in mind that this condition cannot be observed as in two cases of our series and it will show similar physical examination findings of soft-tissue injuries.…”

MR Imaging of Carpal Fractures

“…[46][47][48][49][50][51] Dorsal triquetral fractures can occur with a fall forward onto a palmar flexed hand or backward onto a dorsiflexed hand. [46][47][48][49] There are 2 leading theories regarding the cause of dorsal triquetral fractures. One theory suggests that the fracture results as an avulsion injury from dorsal capsular ligaments, 46,47 whereas the other suggests that the fracture is a result of a chisel action caused by an elongated ulnar styloid process.…”