Introduction

The association of a capitate fracture with a scaphoid fracture has been termed the naviculocapitate syndrome. In general, however “the naviculocapitate syndrome” has been defined by Fenton and Rosen(1,2) as associated fractures of the scaphoid and capitate with rotation of the head of the capitate through 90⁰ or 180⁰; the existence of some nondisplaced fractures of scaphoid and capitate with or without the fracture of lunate or radius suggests that there is a spectrum of these injuries, and this confuses the terminology(3).

With our case; we want to report an unusual variety of this naviculocapitate syndrome with distal radial colles fracture addition to the nondisplaced fractures of scaphoid and capitate and the dorsal lip of radial fracture.

Case Report

We are reporting a case report of a 21 years old soldier who fell down-stairs probably with his left hand outstretched during the penthatlon training period. Initial X-ray examination(Figure 1) showed a Colles and dorsal lip fracture of distal radius with undisplaced scaphoid and capitate fractures. After the closed reduction in the emergency room; long arm cast applied in pronated forearm, flexed and radial deviated wrist position with the elbow flexed at 95 degrees. Control X-rays(Figure 2) and wrist CT(Figures 3-4-5-6) were taken to see the position of the fracture sides for more details and the management decision.

There was no rotation of capitate to the articular surface of lunate or other direction. It was nondisplaced and impacted. Also there was no displacement greater than 1 mm in all position radiographs of the waist fracture of the scaphoid. Scapholunate and lunocapitate angles were all in normal ranges.

There was no dorsal angulation or radial shortening in the reduction position of the colles fracture and the comminuted fracture of the dorsal lip of radius did not involve more than the one third of the articular face. Because of these criterias conservative long arm cast management decided for the treatment.

Review Of The Literature And Discussion

The mechanism of the injury is debatable. Stein and Siegel(4) suggested that the fracture of the capitate was caused by impaction on the dorsal lip of the radius, when the wrist was dorsiflexed, a view that was supported by Monahan and Galasko(5). However, Aitken and Nalebuff(6) stressed that hyperflexion could produce peri-lunate dislocation and this mechanism was thought to be important in three of the cases reported by Vance et al(7).

In general; the cause of scaphocapitate syndrome is hyperextension of the wrist, in which the dorsal ridge of the distal radius acts as a fulcrum, fracturing the scaphoid through the waist and the capitate through the neck region. As the wrist continues to hyperextend, the head of the capitate and the proximal fragment of scaphoid rotate together, and the distal portion of the capitate translates dorsally on the proximal pole. When the wrist returns to a neutral position, the distal segment of capitate spins the capitate head by as much as 180⁰(Figure 7). As a result, the fracture surface of the capitate head comes to lie adjacent to the articular surface of the lunate. Obviously, the capitate will not unite in this malreduced position. This is a difficult diagnosis to make and must be looked for carefully on radiographs. CT may be of value in assessing the degree of displacement, and in identifying associated injuries.

Whatever the mechanism, most authors think that the scapho-capitate syndrome is a variety of trans-scaphoid transcapitate peri-lunar fracture dislocation which has usually reduced spontaneously. The associated wrist fractures reported in the literature would tend to support this view and suggest that ligamentous injuries are frequently underestimated. Although naviculocapitate fracture syndrome is rare, it should be considered among those associated injuries that can occur with a fracture of scaphoid(8).

Up to 1993, 25 cases of scaphocapitate syndrome reported as the review of the literature and in nearly one-third of the cases there was a delay of more than15 days in diagnosis. In 13 cases there was an initial peri-lunate dislocation, which was dorsal in 11. Eight patients had other carpal and wrist fractures( Four of the radius, two of the ulnar styloid, and two of the triquetrum.). Other major fractures occured in seven as a result of high-energy injury(9,10). From 1993 to now; 22 cases of scaphocapitate syndrome reported in the literature with a an average of 6 days delay in diagnosis(11,12,13,14). These delays in diagnosis shows that this syndrome is a result of a complex injury pattern and must be diagnosed more carefully.

According to our idea, the decrease of delaying in the diagnosis in the last 16 years may be the result of the improvement in radiologic imaging techniques. In our case, we used the MDCT(Multidedector computed tomography)to see the configuration and also not to misdiagnose the other wrist injuries(15,16,17). We saw that the dorsal lip of the radius was fractured and undisplaced fractures of scaphoid and capitate tended us that this could be a scaphocapitate syndrome. Because of this reason, we are offering that; every complex injury of the wrist with minimal two bone fractures must also be evaluated with MDCT for not to misdiagnosis. The coronal and sagittal images that obtained from the MDCT is useful and effective imaging modality in using the diagnose of complex wrist fractures with more details that are not dedected in X-rays.

With our report we wanted to show this rare syndrome with colles fracture. When we look at the literature there is no another colles fracture reported together with undisplaced scaphocapitate syndrome. Also using MDCT is an effective imaging method for diagnosing the fractures of the hand especially in complex wrist fractures.

Figure 1

Figure 1

Figure 2

Figure 2

Figure 3

Figure 3

Figure 4

Figure 4

MDCT showed us the fracture of scaphoid and capitate with more details as seen in figures 3 and 4.

Figure 5

Figure 5

Figure 6

Figure 6

MDCT also showed us the nondisplaced fracture of the scaphoid in figure 5 and capitate in figure 6 in lateral views.

Figure 7

Figure 7

Mechanism of carpal fractures from falls on outstretched hand with wrist going into marked dorsiflexion. A, Wrist in marked dorsiflexion. Note that capitate is at 90-degree angle to radius. Scaphoid fractures as result of increased dorsiflexion at midcarpal joint. B, Dorsal lip of radius strikes capitate, causing it to fracture. C, Proximal fragment of capitate is rotated 90 degrees. D, Return of wrist to neutral position. Note that proximal fragment of capitate is now rotated 180 degrees.