Tendon injuries after distal radius fractures Introduction: Tendon injuries after distal radius fractures are a well-documented complication that can occur in fractures managed both operatively and non-operatively. The extensor tendons, in particular the extensor pollicis longus (EPL) tendon, can be damaged and present late after initial management in a cast, or by long prominent screws that penetrate the dorsal cortex and cause attrition. Similarly, a prominent or distally placed volar plate can damage the flexor pollicis longus tendon (FPL). The aim of our study was to evaluate the incidence of tendon injuries associated with distal radius fractures. We conducted a single centre prospective observational study. Patients aged 18–99 who presented with a distal radius fracture between May 2018 to April 2020 were enrolled and followed-up for 24 months. Tendon injuries in the group were prospectively evaluated. Results: 199 patients with distal radius fractures were enrolled. 119 fractures (59.8%) had fixation and 80 (40.2%) were managed incast. In the non-operative group, 2 (2.5%) had EPL ruptures at approximately 4 weeks post injury. There were no extensor tendon ruptures in the operative group. In the operative group, there were 6 (5%) patients that required removal of metalware for FPL irritation. At the time of operation, there were no tendon ruptures noted. Within the operative group we evaluated plate prominence using a previously described classification (Soong et al.). 5 of the 6 patients (83%) with FPL irritation had Grade 3 prominence. The incidence of both flexor and extensor tendon injury in our cohort was 4%, extensor tendon rupture was 1% and flexor tendon rupture was avoided by early metalware removal. This study demonstrates tendon injuries are not uncommon after distal radius fractures, and close examination and follow-up are necessary to prevent eventual rupture. Plate prominence at the time of fixation should be minimised to reduce the risk of rupture

Extensor tendon ruptures have been reported in up to 8.8% of patients after volar plating and long screws have been implicated. The dihedral dorsal surface of the distal radius hinders accurate screw length determination using standard radiographic views (lateral; pronation and supination). A ‘dorsal tangential’ view has recently been described, but has not been validated. To validate this view, we mounted a plate-instrumented sawbone onto a jig. Radiographs at different angles were reviewed independently by 11 individuals. Skyline views clearly demonstrated all screw tips, whereas only 69% of screw tips were identifiable on standard views. With screws 2mm proud of the dorsal surface, skyline views detected 67% of long screws (sensitivity). The best of the standard views achieved only 11% sensitivity. At 4mm long, skyline sensitivity was 85%, compared with 25% for standard views. At 6mm long, 100% of long screws were detected on skylines, but only 50% of 8mm long screws were detected by standard views. Inter and intra-observer variability was 0.97 (p=0.005). For dorsal screw length determination of the distal radius, the skyline view is superior to standard views. It is simple to perform and its introduction should reduce the incidence of volar plate-related extensor tendon rupture

Introduction. Getting the distal locking screw lengths right in volar locking plate fixation of distal radius is crucial. Long screws can lead to extensor tendon ruptures whereas short screws can lead to failure of fixation, especially if there is dorsal comminution of the fracture. The aim of our study was to determine the distal radius anatomy in relation to sagittal lengths and distance between dorsal bone edge and extensor tendons based on MRI scan. Method. One hundred consecutive MRI scans of wrist were reviewed by two of the authors on two occasions. All MRI scans were performed for different wrist pathologies except distal radius fractures or tumours. An axial image, two cuts proximal to the last visible articular surface, was selected. Sagittal length at 5 different widths, maximum volar width, radial overhang over distal radio-ulnar joint and the distance between dorsal bone edge and extensor tendons were measured. Results. A total of 120 MRI scans were included of which 74 were women and 46 were men. Mean volar width was 32mm and longest sagittal length was 22 mm (at Lister's tubercle). Length radial to Lister's tubercle was the shortest (17mm) and ulnar sides were 21mm and 29mm. Male measurements were mean 3mm longer than females. Mean radial overhang over DRUJ was 4mm. Distance from bone to tendons was within 2mm of dorsal radius edge. Conclusion. The study provides a reference guide to average screw lengths at different widths of distal radius in males and females. EPL tendon is closest to bone although all the extensor tendons are within 2mm of bone edge and carry a risk of injury from drill and screw placement. DRUJ is also at risk of injury if screws are placed within 4mm of ulnar edge of distal radius