Both Bone Forearm Fracture with Complex DRUJ Dislocation: What Are the Odds?

Abstract

Background  Distal radioulnar joint (DRUJ) dislocation can occur as an isolated injury or in association with fracture radius (Galeazzi fracture-dislocation), Essex–Lopresti lesion or, rarely, with fracture of both radius and ulna (termed “Galeazzi type fracture”). DRUJ dislocations can be simple or complex. While simple DRUJ dislocation can be reduced by closed methods once the associated fractures are fixed anatomically, complex dislocation does not reduce by closed means. A complex DRUJ dislocation occurring in a both bone forearm fracture is an extremely unusual pattern of injury.

Case Description  We describe the clinical presentation, intraop findings, management, and follow-up of two such cases of both bone forearm fracture with complex DRUJ dislocation. In both the cases, the ulnar head was found to be buttonholed through extensor retinaculum between the extensor tendons. Open reduction had to be done via dorsal approach. Timely intervention allowed good results in both the patients.

Literature Review  Several authors have reported simple DRUJ dislocations in both bone forearm fractures; however, we could come across only three cases of complex DRUJ dislocation in a both bone forearm fracture. A summary of various series and reports on these injuries is presented.

Case Relevance  Through this case report, we want to highlight this unusual association and emphasize on sequence of fixation, so that this perilous injury pattern is not missed, and favorable outcomes could be obtained through appropriate and timely intervention.

Distal radioulnar joint (DRUJ) dislocation is an injury which requires careful attention, as missed injuries can result in painful wrist and/or decreased supination and pronation. This injury can occur as an isolated injury or in association with fracture radius, Essex–Lopresti lesion or, rarely, associated with fracture of both radius and ulna. ¹ The unusual combination of both bone forearm (BBFA) fracture with DRUJ dislocation was given the term “Galeazzi type fracture” by Mikic ² in 1975 and since then, only a few case reports have been described in the literature. ^{3 4 5 6 7} DRUJ dislocations can be simple or complex. In the simple injury, DRUJ can be reduced by closed methods once the associated fractures are fixed anatomically. ⁵ On the other hand, the complex dislocation does not reduce by closed means due to the distal ulna buttonholing between the extensor tendons or in some cases due to bony fragment in the joint. ⁵

To the best of our knowledge, there are only three cases reported in literature of BBFA fracture associated with complex dislocation of DRUJ. ^{5 6 7} We are describing the management and follow-up of two such patients (one acute and one neglected injury). A DRUJ dislocation is frequently missed, especially in cases of associated fractures where patient's pain localization and physician's focus on the fracture in X-ray cause DRUJ problems to be neglected. With paucity of literature on this injury pattern, it is unclear what should be the sequence of fixation in these cases.

Through this case report, we want to highlight this unusual association with its probable mechanism and emphasize on the sequence of surgical steps, so that this perilous injury pattern is not missed, and favorable outcomes could be obtained through appropriate and timely intervention.

Case Reports

Case 1

A 24-year-old man presented with closed injury to right forearm after falling from motorbike. There was no neurovascular deficit and no other injuries. Radiographs revealed fractures of shaft of radius and ulna along with dorsal DRUJ dislocation ( Fig. 1A ). On the posteroanterior (PA) view of the wrist, there was increased gap between the radius and ulna with the ulnar styloid visible in the gap ( Fig. 1B ). On the supination oblique view, the ulnar styloid could be seen volar to the distal ulna ( Fig. 1B ). The limb was initially supported with a splint, and the patient was planned for surgery.

Fig. 1.

Case 1. ( A ) Preoperative anteroposterior (AP) and lateral radiographs showing ulnar head dislocated dorsally. The arrows represent the direction of forces possibly acting to cause this injury which is likely to be a combination of direct impact (green arrow) and axial force with rotational component (red arrows). ( B ) The yellow star marks the displaced ulnar styloid on the AP and supination oblique views. ( C ) Postop radiographs showing reduced distal radioulnar joint (DRUJ). (D) 10 months follow-up radiographs showing the healed fractures.

Surgical steps: The radius was exposed from the volar approach. The fractured radius was anatomically reduced and fixed using a seven-holed limited contact dynamic compression plate (LC-DCP). Once the radius was stabilized, the DRUJ was examined. The ulnar head was prominent dorsally, and attempt to push it volarly could not reduce it while giving a mushy feel. The X-ray and clinical findings suggested a complex dislocation. The ulna fracture was exposed next; however, we did not proceed with plating at this stage, fearing reduction in angulation due to the persistent DRUJ dislocation.

DRUJ was exposed by dorsal approach. After incising the skin, the ulnar head was visualized buttonholed through the extensor retinaculum. The extensor carpi ulnaris (ECU) tendon was displaced volar from the ulnar side and was attached to the ulnar styloid fragment through its sheath ( Fig. 2 ). The ECU sheath was left undisturbed. The extensor digiti minimi (EDM) tendon was found volar to the ulnar head, passing from the radial side. This buttonholing of the ulnar head between the EDM and ECU was not allowing the reduction. Once the tendons were delivered dorsally, the ulnar head reduced into the sigmoid notch and the ulnar styloid fell in its place.

Fig. 2.

Diagrammatic representation of the intra-operative findings of case 1 showing ulnar head buttonholed dorsally through the extensor retinaculum (blue arrowhead) between the tendons of extensor digiti minimi (EDM) and extensor carpi ulnaris (ECU). The red arrowhead marks the broken ulnar styloid.

The ulna fracture was then anatomically fixed using a six-holed LC-DCP. The forearm supination and pronation were confirmed to be full. To stabilize the DRUJ, ulnar styloid was fixed to the ulna using 1.2 mm K-wires and 24G SS (stainless steel) wire. The DRUJ stability and supination/pronation were checked again, and the reduction was confirmed under fluoroscopy. The DRUJ was fixed using 1.4 mm K-wire in supine position. The postoperative radiographs are shown in Fig. 1C .

Postoperatively, the limb was immobilized using an above-elbow slab. The postoperative period was uneventful, and mobilization was started at 6 weeks after removing the DRUJ wire. At 10 months follow-up, the fractures were healed ( Fig. 1D ). The supination was 60 ° and pronation was 70 ° ( Fig. 3 ). The wrist range of motion (ROM) was normal. Grip strength was 90% compared with the opposite side. Patient had 2/10 pain score on activity while no pain at rest. He had no restriction of activities.

Fig. 3.

Ten months postoperative supination, pronation, radial and ulnar deviation.

Case 2

A 24-year-old man presented to us with decreased movements of the right forearm nearly 1 year after injury. He had suffered fractures of both bones of right forearm. He also had fractures of right 4th metacarpal, proximal phalanges of right index and middle finger and left distal radius. Initial management was performed at a different center. The left distal radius was managed by plating and there were no symptoms on this side. The right radius and ulna were managed operatively. The fractures of the metacarpal and phalanges were managed nonoperatively.

On examination, the surgical scars were healed. There was no supination and approximately 20 ° of pronation ( Fig. 4A ). The distal ulna was prominent dorsally with a healed scar over it, suggestive of an open injury initially ( Fig. 4B ). The proximal phalanx fractures were united in angulation, leading to a pseudo claw deformity of the index and middle fingers.

Fig. 4.

Case 2. ( A ) Preoperative supination and pronation. ( B ) Prominent ulnar head on the dorsum with healed scar. ( C ) Postoperative radiographs after the index surgery with dorsally dislocated ulnar head. ( D ) X-rays before the surgery for distal radioulnar joint (DRUJ) reduction. ( E ) X-rays after open reduction showing hemiresected ulnar head and reduced DRUJ held in place with two K-wires. ( F ) 16 months follow-up X-rays showing no gap at DRUJ and maintained reduction. ( G ) Clinical images at 16 months follow-up showing 60 ° supination and 20 ° pronation with good flexion and extension at wrist.

The patient could not provide the initial trauma films. However, the dorsally dislocated distal ulna could be seen clearly on the postoperative X-rays after the index procedure ( Fig. 4C ). The ulnar styloid was visible volar to ulna on lateral view and overlapping with ulna on the PA view.

The fractures of radius and ulna were healed on recent X-rays ( Fig. 4D ). The distal ulna was dislocated dorsally. There was new bone formation ulnar to the distal ulna.

We planned for open reduction of DRUJ with hemiresection of ulnar head as backup.

Surgical steps: The DRUJ was approached from a dorsal incision. There was fibrosis over the ulnar head, which was found next to the subcutaneous tissue. The findings were identical to our description in the first case with the ulnar head buttonholed between the EDM and ECU ( Fig. 5A ). The new bone over the ulnar aspect of ulnar head was elevated from the ulna. EDM and ECU tendons were delivered dorsal to the ulna. The fibrous tissue between the distal radius and ulna was dissected. The cartilage over the ulna was poor; hence, hemiresection of ulnar head was also done. After the soft-tissue release, by gradually increasing supination and volar pressure on ulna, we were able to reduce the joint. The DRUJ was then fixed in the reduced position with two 1.4 mm K-wires ( Fig. 4E ). The fibrous tissue attached to the radius was then used to repair the dorsal capsule over the DRUJ ( Fig. 5B ). An ulnar based slip of extensor retinaculum was elevated from the 2nd to 4th extensor compartments and used to create ECU sheath ( Fig. 5C ).

Fig. 5.

Intraoperative pictures of case 2. ( A ) Ulnar head button-holed between the extensor digiti minimi (EDM) and extensor carpi ulnaris (ECU). ( B ) Fibrous tissue used to repair the dorsal capsule over the distal radioulnar joint (DRUJ). ( C ) Ulnar based slip of extensor retinaculum elevated from the 2nd to 4th extensor compartments and used to create ECU sheath (blue arrowhead).

The DRUJ wires were removed at 6 weeks and mobilization started. At 16 months follow-up, the radiographs showed no gap at DRUJ with maintained reduction ( Fig. 4F ). The patient had 60 ° supination and 20 ° pronation ( Fig. 4G ). Wrist flexion and extension were near full. His pain score was 2/10 on activity. With associated deformities in the fingers, he had obvious weakness of the grip.

Discussion

The radius and ulna articulate with each other at the proximal radioulnar joints (PRUJ) and DRUJ and the interosseus membrane. These joints combined can be considered as the forearm joint. ¹ There are various patterns of injuries affecting these joints in isolation or in combination. Monteggia, Galeazzi and Essex–Lopresti injuries are the most common with other rare patterns such as the one described above. These injuries have been grouped in Galeazzi fracture variants in the past. ^{2 4 8} In a comprehensive three-locker based classification, the combination of BBFA fracture with DRUJ dislocation has been classified as 2RIU.3. ¹

The mechanism of both bone forearm fracture in combination with DRUJ dislocation is difficult to explain. The force passing through radius and then exiting through the ulna and DRUJ is unlikely. ^{2 9} We believe that this pattern is possible if there are axial and rotational forces (as described for Galeazzi fracture), acting in combination with direct impact on the ulna at the fracture site ( Fig. 1 ). Further studies are needed to clearly decipher the mechanism of this injury complex.

Many articles have reported this injury pattern ( Table 1 ), however, the most common type of DRUJ injury in such cases is simple. The presence of a complex or irreducible DRUJ dislocation is rare and to the best of our knowledge, only three such cases have been reported in the past. In all of these cases, the DRUJ injury was missed on the initial surgery and was reduced as a second procedure. ^{5 6 7}

Table 1. Summary of various cases of both bone forearm fracture with DRUJ dislocation.

S. no.	Name of author	Number of cases	Simple/complex
1.	Mikić 2	25	All simple
2.	Bruckner et al 5	1	Complex
3.	Budgen et al 7	1	Complex
4.	Jenkins et al 6	1	Complex
5.	Vaishya et al 4	6	All simple
6.	Ryan et al 3	1	Simple
7.	Present case	2	Both complex

Abbreviation: DRUJ, distal radioulnar joint.

The treatment of choice in such cases is open reduction and fixation for the radius and ulna shaft fractures. ⁵ With simple DRUJ dislocation, the restoration of the alignment of diaphyseal fractures should reduce the DRUJ.

Identifying complex DRUJ dislocation in this injury pattern is paramount as unreduced DRUJ causes pain in the wrist and restriction of supination and pronation. ¹⁰ Second, if the injury is missed during the primary surgery, there is a high possibility of fixing the radius or ulna in angulation.

There are certain signs that can indicate presence of a complex DRUJ dislocation. In the acute injury, one can assess the tenderness at the DRUJ. On the wrist X-rays, widening of the DRUJ on PA view, the presence of a completely dislocated ulna head, and volar displacement of the ulna styloid should raise the suspicion. ⁵ Intraoperatively, the radius should preferably be stabilized first. The inability to push the dorsally prominent ulna volarly and a mushy feeling should prompt the surgeon to consider open reduction of the DRUJ. Once the DRUJ is reduced, the ulna is fixed, and as the last step, DRUJ is stabilized.

In every patient with forearm diaphyseal fracture, at the end of fixation, it is important to confirm that the supination and pronation have been restored. This confirms that the rotational alignment at the fracture site is correct. ^{5 10} More importantly, it confirms that the DRUJ and PRUJ are reduced. ^{5 10}

The findings of complex DRUJ dislocation have been described in the past and detailed discussion on this is beyond the scope of this article.

Even though there is paucity of literature to guide for the treatment and results of this unusual combination, we believe that surgical fixation can yield good functional outcome for this injury if the anatomy is restored and the treatment is done early.

In conclusion, intraoperative examination of DRUJ is a must in the “Galeazzi type fractures” and any irreducibility/instability at DRUJ should be dealt with appropriately. These injuries can be best managed in the acute setting with the prognosis getting worse in neglected cases.

Funding Statement

Funding None.