Ulnar styloid fractures associated with distal radius fractures: incidence and implications for distal radioulnar joint instability

Traumatic injuries of the distal radioulnar joint

Traumatic injuries of the distal radioulnar joint (DRUJ) may give rise to complex wrist pathologies. Substantial ongoing disability can arise should these injuries go unrecognized resulting in sub-optimal treatment and lack of appropriate rehabilitation. Injuries of the DRUJ may occur in isolation but more commonly are found with a fracture of the radius. These challenging DRUJ injuries may be simple or complex (irreducible or severe instability), acute or chronic. An adequate knowledge of the stabilizers of the DRUJ is essential in understanding treatment options. Traumatic instability of the DRUJ is reviewed and the anatomy and stabilizing factors are discussed. An algorithm to guide selection of treatment options in complex cases is presented.

Surgical treatment of unstable distal radius fractures with volar locking plates

BACKGROUND

Surgical treatment of unstable distal radius fractures does not always yield a satisfactory outcome. The several surgical strategies available have problems associated with them. This study was undertaken to determine if volar locking plate fixation could be useful for treating unstable distal radius fractures.

METHODS

This retrospective follow-up study assessed 24 fractures in 24 patients with unstable distal radius fractures surgically treated with one of three volar locking plate systems. According to the AO classification system, 7 patients had type A3 fractures, 5 patients had type C2 fractures, and the remaining 12 patients had type C3 fractures. Radiographic measurements included volar tilt, radial inclination, and ulnar variance. Clinical outcomes were evaluated by active range of motion of the wrist and forearm, grip strength, Saito's wrist score, and the Japanese Society for Surgery of the Hand version of the Disabilities of the Arm, Shoulder, and Hand questionnaire (JSSH version of the DASH).

RESULTS

At the time of final follow-up (5 months minimum) the mean volar tilt was 8.1 degrees , radial inclination was 20 degrees, and ulnar variance was 0.4 mm. Mean wrist extension measured 61 degrees, wrist flexion 55 degrees, radial deviation 23 degrees, ulnar deviation 35 degrees, pronation 87 degrees, and supination 87 degrees. Grip strength recovered to a mean of 84% of the grip strength in the contralateral limb for patients who had injured their dominant hand and to a mean of 73% for patients who had injured their nondominant hand. Saito's wrist score calculations revealed 20 excellent and 4 good results. The mean DASH disability/symptom score was 9.9 points, and the mean DASH work module score was 8.2 points.

CONCLUSIONS

The present study demonstrated that unstable distal radius fractures could be successfully treated with volar locking plate systems.

The treatment of severely comminuted intra-articular fractures of the distal radius

Comminuted fractures of the distal end of the radius are caused by high-energy trauma and present as shear and impacted fractures of the articular surface of the distal radius with displacement of the fragments. The force of the impact and the position of the hand and carpal bone determine the pattern of articular fragmentation and their displacement and the amount and the extent of frequent concommitant ligament and carpal bone injury. The result of the osseous lesion in comminuted fractures was termed "pilon radiale", which emphasizes the amount of damage to the distal radius and the difficulties to be expected in restoring the articular congruity. Besides this the additional injury, either strain of disruption of the ligaments and the displacement of the carpus and/ or the triangular fibrocartilage complex will equally influence the functional outcome. This review will expand on the relevant anatomy, correct classification and diagnosis of the fracture, diagnostic tools and operative treatment options. Current treatment concepts are analysed with regard to actual literature using the tools of evidence based medicine criteria. A new classification of severely comminuted distal radius fractures is proposed using CT data of 250 complex intraarticular radius fractures. Finally a standardized treatment protocol using external fixation in combination with minimal invasive internal osteosynthesis is described.

Distal radius fractures: a comparison of tension band wiring versus ulnar outrigger external fixation for the management of distal radioulnar instability

PURPOSE

To retrospectively compare the results of immobilization of the forearm in supination with the results of tension band fixation of the ulnar styloid in 35 patients with distal radius fractures, fracture of the base of the ulnar styloid, and distal radioulnar joint instability treated with external fixation.

METHODS

Thirty-five patients with fractures of the distal radius, fracture of the base of the ulnar styloid, and unstable distal radioulnar joint had external fixation with adjunctive percutaneous pins and allograft bone to reduce and stabilize the distal radius fracture anatomically. Only those patients with an associated ulnar styloid base fracture displaced over 2 mm with gross distal radioulnar joint instability relative to the contralateral wrist were included in this study. Group 1 consisted of patients in whom the ulnar styloid base fracture was treated with conventional tension band wiring techniques. Group 2 patients were treated with a supplemental outrigger from the external fixator to the ulna and locked in 60 degrees of forearm supination. Groups 1 and 2 had an average follow-up period of 40 and 36 months, respectively.

RESULTS

Group 2 had significantly better supination than group 1. In terms of functional outcome it was found that there was no significant difference for the Disabilities of the Arm, Shoulder, and Hand and the Gartland and Werley scores between the 2 treatment groups. There was a lower rate of complications and fewer secondary procedures were required in group 2. The incidence of distal ulna resection was 4 of the 35 patients (2 patients in each group).

CONCLUSIONS

Our results indicate that patients in whom the ulnar styloid can be reduced and maintained in supination can be treated effectively with fixed supination outrigger external fixation. This method resulted in a statistically significant improvement in supination and a lower rate of distal radioulnar joint complications, and it required fewer secondary procedures.

Avoidance and treatment of complications of distal radius fractures

The treatment of distal radius fractures continues to be fraught with complications. The more widespread use of internal fixation and supple-mental bone grafting with external fixation has decreased the incidence of malunions from closed-cast treatment and percutaneous pinning, but increased the risk of the complications specific to surgical intervention. Careful diagnosis, surgical planning, surgical technique, and postoperative rehabilitation can help optimize outcome in these difficult fractures.

Plating of the distal radius

Distal radius fractures are common injuries that can be treated by a variety of methods. Restoration of the distal radius anatomy within established guidelines yields the best short- and long-term results. Guidelines for acceptable reduction are (1) radial shortening < 5 mm, (2) radial inclination > 15 degrees , (3) sagittal tilt on lateral projection between 15 degrees dorsal tilt and 20 degrees volar tilt, (4) intra-articular step-off < 2 mm of the radiocarpal joint, and (5) articular incongruity < 2 mm of the sigmoid notch of the distal radius. Treatment options range from closed reduction and immobilization to open reduction with plates and screws; options are differentiated based on their ability to reinforce and stabilize the three columns of the distal radius and ulna. Plating allows direct restoration of the anatomy, stable internal fixation, a decreased period of immobilization, and early return of wrist function. Buttress plates reduce and stabilize vertical shear intra-articular fractures through an antiglide effect, where-as conventional and locking plates address metaphyseal comminution and/or preserve articular congruity/reduction. With conventional and locking plates, intra-articular fractures are directly reduced; with buttress plates, the plate itself helps reduce the intra-articular fracture. Complications associated with plating include tendon irritation or rupture and the need for plate removal.

MR imaging findings in ulnar-sided wrist impaction syndromes

Ulnar-sided wrist impaction syndromes are a common source of ulnar pain and limitation of motion. These conditions refer to a group of pathologic entities that result from repetitive or acute forced impaction between the distal ulna and ulnar carpus or distal radius and surrounding soft tissues. MR imaging allows earlier detection of the bone and soft-tissue lesions that are present in the different ulnar-sided wrist impaction syndromes and is helpful in formulating the extensive differential diagnosis in patients with ulnar wrist pain and limitation of motion.