Radiocarpal fractures-dislocations:
Spectrum of injuries and management

APERGIS E, DARMANIS S, PIOTOPOULOS A, KARADIMAS E,
GARAS G, ANASTASOPOULOS S.

ABSTRACT
Radiocarpal dislocations or fracture-dislocations are unstable and unusual injuries. They must be differentiated from the intraarticular shearing fractures of the distal radius accompanied with wrist subluxation, because they are entirely different injuries. The aim of this paper is to record the differences of these injuries and to describe the surgical findings and long-term results of 16 patients who were treated early and late.
Sixteen patients were treated of 28,7 mean age (23-30 years old) with radiocarpal fracture-dislocation after a high-energy injury. The dislocations were of dorsal direction in 10 cases, palmar direction in 5 and multidirectional in one patient. Associated injuries were found in 43,7% of patients. In 12 cases the radiocarpal dislocation were of type I and n 4 cases were of type II. The spectrum of osseous injuries associated with radiocarpal dislocation presented high variation. Depending on treatment, the patients were classified into surgical group A with 13 patients and conservative group B with 3 patients. From group A, 9 patients were operated early and 4 with a delay of 4,5 months average (3-6 months). Surgical technique was individualized and a combined approach was used in 8 cases, although a single approach was used in 5 cases.
Results evaluated after an average follow-up of 2 years (8-84 months) with a modification of scoring system of Viegas. For group A, 3 patients had excellent, 6 good, 2 fair and 2 poor results. For group B one patient had excellent result and 2 patients considered as fair result.
In conclusion, radiocarpal fracture dislocations: a) Must be distinguished from the shearing type of fractures mostly for reasons of management, b) The pathology concerns the radiocarpal (both dorsal and volar) and ulnocarpal ligaments or their osseous attachments, c) Independently of direction of the dislocation, volar approach and stabilization of the radiocarpal joint are of paramount importance, d) Surgical reconstruction, although more difficult, had favorable results even after delayed treatment.

Key words:Radiocarpal dislocation, fracture-dislocation, wrist injury, management.

INTRODUCTION
The radiocarpal dislocations or fracture - dislocations, are unstable and rare injuries, as most reports in the literature describe a relatively small number of cases or subitary cases. Further more, for these injuries there exists a relative vagueness as to the classification, concerning that they are confuted with the intra articular fractures - separations (Barton type or Fernandez type II) pf the distal radius, whenever these are associated with a subluxation of the carpus. This classification vagueness could create therapeutic problems because we deal with two entirely different injuries. The spectrum of osseons and ligametons lesions as well as the method of management of these injuries consists a controversial subject.
The aim of this paper is to point out the differences of the rediocarpal dislocations with the fractures separations of the distal end of radius, to describe the spectrum of lesions and to study the long - term results of 16 patients with radio - carpal dislocation who were treated primarily as well as delayed.

1A. 1B. 1C.
1D. 1E. 1F.

1G. 1H,
Figure 1 (case 1). The initial radiology shows avulsion fracture of the dorsal pole of the triquetrum (a) and a small fracture of the ulno - volar radial rim (b) (arrows). Radiology 6 months after the injury: on the posters anterior view one case see the overlapping of the radiocarpal joint, the double margin of the fracture of ulnovolar radial rim (arrows) and the avulsion fracture of the triquetrum (c),while on the lateral view the wrist subluxed voralrly,articulating with newly formed bone from the ulnovolar radial rim (d). Postoperative radiography (e,f) and final radiographic control 18 months postoperatively (g,h).

MATERIAL AND METHOD
In the period between 1993-1999 we treated 15 men and one woman of 28,7 years (23-30 years) who suffered close fracture - dislocation of radiocarpal joint after a high-energy injury (road traffic accident).
The dislocations of the wrist in 10 cases had dorsal direction, in 5 palmar, while in one case the carpal dislocation was multidirectional (dossal as well as palmar).
Seven patients (43,7%) had associated injuries concerning the contralateral limp (4 cases), the vertebral column (one case), the opposite knee (one case) and the skull (one case). One patient presented with an injury of the brachial artery of the opposite arm.
In 12 cases the radiocarpal fracture - dislocation was pure, without injury of the interosseons, ligaments of the proximal carpal row (Type I), while in 4 cases the radiocarpal injury was associated with rupture of the interosseons ligaments (TypeII) (of the scapholunate ligaments in 3 cases and of the lunate - triquetrum ligament in one case). In all the cases of type II injuries, the rupture of the interisseous ligaments was found intraoperatively.
The spectrum of osseons lesions that accompanied the rediocarpal dislocation and were visible at radiology, included: the styloid process of radius (10 cases), the nenar styloid (9 cases), the dorsal radial margin (4 cases), while in 4 cases we spotted a small bone chip avrilsed from the distal articular surface of radius. Besides, in 3 cases, we observed avulsion fractures of the triquetrum (2 cases) and the lunate (one case). The fracture of the radial styloid in 2 cases concerned its apex (Type 1), in 3 cases the fructure line reached the middle of the scaphoid fosset (Type 2), while in 5 cases it reached the ridge between the scaphoid and lunate fosset (corresponding to the scapho - lunate space) (Type 3).
The fracture of the ulnar styloid consisted an associated lesion in 9 cases, of which the 8 involved its base and only one case involved its apex.

2A. 2B. 2C.
2D.
Figure 2 (case 12). Dorsal rdiocarpal dislocation with fracture of radial styloid type 2 (a, b). Restoration of the fracture by means of tension band and of volar and dorsal radiocarpal ligaments with bone anchorage. Bone anchorage to the lunate restores the avulsed short radiolunate ligament (c,d).

The patients were separated into two groups, according their therapeutic management. Group A included 13 patients that were treated surgically, and group B 3 patients managed with close reduction and immobilization in POP.
Among the patients of group A, nine were operated on a few hours after the accident, while 4 patients that originally had been managed conservatively had to be operated in the end, at a mean time of 4,5 months after the injury (3-6 months) with their wrist subluxed. It is interesting that of 4 case, that were treated with delay, two cases had been underestimated because their wrist was reduced and the only radiological finding was a small avulsion fracture from the ulnar - palmar radial rim. As time passed, in both cases the wrist went to palmar subluxation (figure 1).
The approach was combined in 8 cases, while in 5 cases was single (dorsal in 2 cases and palmar in 3). The combined approach was applied, in two cases palmar - ulnar, in another two dorsal - ulnar, while in one case a triple approach (dorsal - palmar - ulnar) was used.
The management was individualized and included.
a) Fixation of the avulsed bone fragment with Kirschner wires (seven cases) or tension band (six cases, of which one was involved the radial styloid and five the ulnar styloid) or Herbert screw (one case) or a T - plate (one case) or Suture through bone holes on the radius (one case) or by means of bone hooks (three cases), according to the size of the bone fragment (Figure 2).
b) Suture of the dorsal or volar radiocarpal ligaments that had been ruptured without bone avulsion (4 cases).
c) Stabilization of the radiocarpal Steinmann pin (3 cases) or with a combination of the above (2 cases).
d) Reduction and fixation with Kischner wire of the ossicles of the proximal row, in the cases of rupture of interosseous ligaments (3 cases).
In the case of the patient with the multidirectional dislocation (Type II lesion) the wrist was reduced, but the tortional face applied, far from complete rupture of the volar and dorsal radiocarpal ligaments, caused also avulsion of extensor longus and abductor longus tentors the thump and separated them from their musculotendinons part.

3A. 3B. 3C.
3D. 3E. 3F.
Figure 3 (case 6). Dorsal radiocarpal fracture - dislocation with fracture of the ulnar and radial styloid type 3 (a, b). This lesion must be classified to the category of separation type because the displayed bone fragments bear the ligamentous attachments that stabilize the joint. Thus, their osteosynthesis secures the stability od the joint (c,d). The final outcome (e,f).

All patients of group B that were treated conservatively, presented with dorsal fracture - dislocation, associated with a considerable part of the radial styloid. The dislocation was reduced under local anesthetic and immobilized in a short POP with the wrist in dorsal extension for 4-6 weeks (The particular of patients surfaces, ulnar shift and height of wrist, scapholunate space).
The results of group A, were considered excellent in 3 patients, good in 6, fair in 2, and poor in 2 patients. In patients with fair and poor results the clinical findings did not correlate with radiology. The radiological result was more unfavorable than the clinical. Nevertheless, despite the fact that symptoms were mild and tolerated by the patients, the long-term results may not be favorable. Of the two patients with fair results, the first with dorsal dislocation type II was treated with suture of the dorsal radiocarpal ligaments, osteosymthesis of the osteosynthesis of the ulnar styloid with tension band, and external fixation, without surgical repair of the volar radiocarpal ligaments. The patient developed progressively moderate ulnar shift of the wrist (ulnocarpal distance of the injured wrist = 0,18 while for the normal wrist was 0,33). The second patient, also with dorsal dislocation type II and compression fracture of the dorsal radial rim, was treated 4 months after the accident with reduction and fixation of the fracture with Kischner wires and external fixation. Postoperatively, there has been only small improvement of the fracture of the dorsal sublaxation of the wrist apparently due to non use of grafts on the depressed dorsal radial rim.
From the two patients with poor results the first, with the multidirectional dislocation type II, developed postoperatively algodystrophy syndrome, while the second, with volar dislocation also type II and comminuted compression fracture of radial styloid, presented with a postoperative depression of radial styloid and 3rd degree incongruity and arthritis of the styloscaphoid joint.
Of the 4 patients that had delayed treatment (mean time 4,5 months after the injury), 3 showed a very good clinical as well as radiological result.
The results of patients of group B were considered as excellent in one case and fair in two cases. One of the patients with fair results presented with defective union of the radial styloid fracture, with an intaarticular step of 2mm and pheudarthrosis of the ulnar styloid. The second patient with fair result showed a mild ulnar shift of the wrist.

DISCUSSION
The radiocarpical fracture dislocations of the wrist are relatively rare injuries. Most reports in the literature describe single cases[69,12,14,19] or a relatively small number of cases[3,13,17]. Up to the present, only, three reports include more than 10 patients[4,15,16].
According to the literature, the radiocarpal dislocations (Type IV after Fernandez) must be differentiated from fractures - separations of the dorsal or volar rim (Barton type, or Fernandez type II) that are associated with subluxation of the wrist[6].
The differentiation of these injuries is imposed, because we have to deal with two injuries of different mature as to the mechanism of injuries of different mature as to the mechanism of injury, the pathology of lesions and their stability after the reduction.
1. In the radiocarpal dislocations, basic component of the mechanism of injury is the application of tortional force via the radiocarpal joint, while for the fractures of separation type the main component is the axial bearing of the wrist on the distal joint surface of the radius.
2. In the radiocarpal dislocations, the lesions are purely ligaments or osseous avulsions of the ligaments attachments. Furthermore, with the wrist dislocation, there is the possibility of causing a compression fracture of one of the two radial rims. On the contrary, in separation-fractures, the separated joint osseons fragment of the radius (usually of the dorsal radial rim) has considerable size, keeps in touch with the proximal carpal row and bears the ligaments attachments of radiocarpal ligaments, significant for the stability of the wrist.
3. In the radiocarpal dislocations the reduction is easily obtained but its maintenance is precarious. On the contrary, in the separation type of fractures, the reduction of the sizeable osseons fragment (close or open) and the maintenance of the reduction, secures the stability of the joint.
Nevertheless, many reports[11,15,17], on the category of radiocarpal dislocations include cases with a sizeable osseons fragment avulsed from the radial styloid, e.g. in the reports of Mudgal et al[15,9] from the 12 cases involved such an osseons fragment. These cases, we believe, should be classified in the category of fractures - separations (Fernandez type II), because the sizeable osseons of the radial styloid has the same functional significance with the volar and dorsal radial rim.
With the exception of the publications of Berger and Amalde[2] and Siegel and Gelberman[18] there are no reports that elucidate the relationship between intraarticular fractures and rupture of volar radiocarpal ligaments.

4A. 4B. 4C.
4D. 4E. 4F.
Figure 4 (case 8). Dorsal radiocarpal subluxation with fracture of the radial styloid type 1 and fracture of the base of the ulnar styloid (a, b). Intraoperatively a complete rupture of the ligament was found (double arrow) (™ = scaphold, M = lunate) (c). Postoperative x-ray (d). The fair final outcome is due to non suture of the volar radiocarpal ligaments that allowed the wrist to displace towards ulnar e,f).

On the grounds of these papers we know that:
Line of fracture of the radial styloid that involves only its apex (Type 1) corresponds to rapture only of the radial lateral ligament. Fracture line that reaches the middle of the scaphoid fosset (corresponding to the middle of scaphoid (Type 2), correlates with rupture of the radial collateral and of the radio - scaphoido - capitate ligament. Finally, fracture line that cones up to the ridge that separates the scaphoid from lunate fosset (corresponding to the scapholunate joints) (Type 3) correlates additionally the rapture of considerable part of the long radiolunate ligament. Consequently, in radio - carpal dislocation with fracture of the radial styloid type 3, the osteosynthesis of radial styloid, more or less restores the stability of the wrist. On the contrary, in radiocarpal dislocations with type 1 fracture of radial styloid, the osteosynthesis of the fracture does not restore stability of the corpus and needs further stabilization (e.g. suture or fixation of ligaments, external fixation ect) (figure 3).
The radiocarpal dislocations or fracture dislocations are high energy injuries and may be associated with great deformity in the area of corpus. Thus, not rarely, they are open injuries, may coexist with neurovascular damage and combine with injuries in other parts of the body[15,16].
According to Moneim et al[13] the radiocarpal fracture dislocations are distinguished in type I, where the lesion involves only the radiocarpal ligaments and those of type II, in which also coexists raptures of one or more interosseons ligaments of the proximal carpal row. In our series, the 4 cases of lesions type II were diagnosed intraoperatively, considering that the rupture of interosseous ligaments was not clear in the ordinary radiological explanation (figure 4).

5A. 5B. 5C.
5D. 5E. 5F.
5G.
Figure 5 (case 5).Volar radiocarpal subluxation with fracture of the ulnovolar radial rim (a,b). Volar stress reveals complete dislocation of the joint with displacement of the bone fragment (c). Postoperative x-ray control (d,e).The final radiological results after 14 months (f,g).

Special attention is needed foe the cases, which are seen with the wrist, reduced after a spontaneous reduction of following manipulation. In these cases, there is always the risk to underestimate the lesion and treat in as an ordinary injury. One of the cases of our series was seen with the wrist reduced spontaneously and the suspicion of lesion was raised from the existence of a small avulsion fracture of the ulnopalmar radial rim. The intraoperative stress radiography secured the diagnosis (figure 5).
Most authors agree on the view that open, radiocarpal dislocations, non reducible and those associated with neurovascular damage, must be treated with open reduction[8,17]. Nevertheless, in many reports, mostly of solitary cases, it is suggested to proceed with close reduction and immobilization with plaster in dorsal extension for the dorsal and palmar flexion for the volar dislocations[1,5,13,14,19].
If we consider that 4 of our cases had been originally managed with close reduction and plaster immobilization, and the wrist was found dislocated when the POP was removed, we believe that this is indicative of the instability of the injury and as Mudgal et al15, we support the view that in all cases open reduction is necessary.
Based on the experience gained by the time and on the surgical findings in cases with recent injury that have been operated on with combines approach, we believe that each radiocarpal dislocation or fracture - dislocation presupposes:
a) Rupture or insufficiency of the volar radiocarpal ligaments or avulsion of their osseons attachments, usually from radius or from ossicles of the corpus.
b) Rupture or insufficiency of the dorsal radiocarpal ligaments or avulsion of their osseons attachments from the dorsal radial rim or from the triquetrum, and
c) Rupture or insufficiency of the volar ulnocarpal ligaments or avulsion of ulnar styloid.
In theory, the restoration of all the lesions would demand a triple approach (volar, dorsal and ulnar). But in practice, in each case of a radiocarpal dislocation and regardless its direction; we consider the volar approach as necessary to be able to restore the significant for the stability of the wrist volar radiocarpal and ulnocarpal ligaments. If, for 6 weeks, we secure the anatomical reduction of the wrist with supplementary means (external fixation and/or radiocarpal Steinmann pin), it is possible that the dorsal radiocarpal ligaments will heal.
The dorsal and/or ulnar approach must be applied in cases of fracture of the dorsal radial rim or in displaced fractures of the ulnar styloid.
The compression fractures of the dorsal or volar radial rim must be distinguished from the avulsion fractures, because the prognosis of the former is worse. Two of our cases with unfavorable outcome presented with compression fracture of the dorsal radial rim and radial styloid respectively. Such cases must be treated with open reduction, placing of cancellous bone grafts and osteosynthesis[15].
Unfavorable factors that influence the final outcome and need special attention are:
1. The existence of a compression fracture of the volar or dossal radial rim or the radial styloid.
2. The existence of fracture avulsed from the ulno - volar radial rim.
3. The occurrence of radiocarpal dislocation type II, associated with neurological damage7.
We conclude that the radiocarpal fractures - dislocations:
1. Consists unstable injuries for which surgical management is suggested.
2. The pathology of the lesion involves the radiocarpal (volar and dorsal) but also the ulnocarpal
ligaments or their osseons attachments.
3. Routine radiology is not enough to classify the lesions in type II and I.
4. The lesion is underestimated in the case of spontaneous reduction.
5. Surgical treatment, although were difficult, produces favorable results even when applied with 6 months delay after the injury.

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