Review Question - QID 217897

This patient has sustained a rupture of her extensor pollicis longus (EPL) secondary to a prominent dorsal screw. Given the attritional nature of this injury, the appropriate surgical management in addition to hardware removal is tendon transfer, typically with the extensor indicis propiris (EIP), which resides in the fourth dorsal compartment (Answer 4).

Distal radius fractures are a common orthopaedic injury and account for nearly 20% of all fractures in adults. They occur in a bimodal distribution, with younger patients sustaining these injuries secondary to high-energy mechanisms, and older patients secondary to low-energy falls. 50% of these injuries are intra-articular in nature. While many of these fractures can be treated nonoperatively, operative management is indicated for unstable injuries, those with extensive intraarticular involvement and those with high degrees of displacement. For most injuries, volar plating is preferred over dorsal plating. Volar plating is not without risk, and prominent screws that penetrate the dorsal cortex can lead to attrition and subsequent rupture of the extensor tendons, most typically the EPL. Verification of proper volar-to-dorsal screw length is best assessed on the skyline view (Illustration A), in which the wrist is maximally flexed and the fluoroscopic beam is aimed 15 degrees volar to the long axis of the radius. Given the attritional nature of this injury, the preferred treatment is the transfer of EIP to the EPL, with concomitant hardware removal.

Benson et al. performed a review of 10 patient cases and six cadaveric specimens to investigate the cause of EPL rupture following volar locking plate fixation of distal radius fractures. The authors uncovered various possible causative errors, including plate design which aims screws into the third dorsal compartment, the presence of dorsal comminution and dorsal gapping. The authors conclude by recommending either the use of shorter screw lengths or leaving the implicated plate holes unfilled. They also support a mini-open evaluation of the third dorsal compartment if a concern is present.

Berglund and Messer provide a review of the complications following volar locking plate fixation of distal radius fractures. The authors highlight the benefits of volar plating, which include biomechanically stable fracture fixation, early rehabilitation, and the ability to achieve fixation in osteoporotic or comminuted bone. They do note, however, that this fixation strategy is not without risk of complication, and that surgeons must utilize sound surgical techniques in order to achieve good patient outcomes. Relevant to this question, they highlight the risk of injury to the extensor tendons (namely EPL) and stress the importance of proper intraoperative radiographic evaluation in order to ensure that dorsal screw prominence is not present.

Figure A is an AP of the right wrist, which demonstrates a displaced distal radius fracture. Figure B demonstrates an intraoperative lateral of the wrist status-post volar locking plate fixation, with a prominent dorsal screw. Illustration A is a graphical representation of the skyline view. Illustration B is an illustration of the dorsal compartments of the wrist and their contents.

Incorrect Answers:
Answers 1, 2, 3, 5: The first, second, third and fifth dorsal compartments do not contain the EIP, which is the most commonly transferred tendon following attritional EPL rupture. Illustration B demonstrates the dorsal wrist compartments and contents.