ABSTRACT
Purpose: Distal radius fractures are the most common fractures in adults. Because of the prevalence of these injuries, patients may present with a repeat distal radius fracture on the same wrist through the site of a malunion. We clinically refer to this as an acute on chronic distal radius fracture. In this setting, the restoration of acceptable alignment can be challenging. There is little guidance in the literature for the management of these fractures. We report our experience with acute on chronic distal radius fractures. The secondary fracture plane was used to correct the prior deformity, and the construct was fixated with a fixed angle volar locking plate. Methods: Records of patients with malunion of the distal radius who experienced an acute fracture of the ipsilateral distal radius were reviewed. Inclusion required treatment with open reduction internal fixation using a distal fragment first technique and a volar locking plate through the extended flexor carpi radialis approach. Clinical outcomes and complications were collected. Results: Across 13 patients, the mean follow-up term was 13 months (range, 6-40 months). Radiographic union was noted in all patients. The mean visual analog scale score for pain was 1.8, and the mean Quick Disabilities of the Arm, Shoulder, and Hand score was 21.9. There were no recorded complications. Conclusion: Our results and described technique provide reproducible guidance for the management of acute on chronic distal radius fractures. These cases can be managed using the secondary fracture plane, a distal fragment first technique, and a volar locking plate to correct the preexisting deformity. Type of study/level of evidence: Therapeutic IV.
ABSTRACT
BACKGROUND: The extensor carpi ulnaris (ECU) tendon has a distinct subsheath at the distal ulna. Symptomatic tears of this subsheath and subluxation of the ECU tendon often require reconstruction. We sought to determine the anatomical constraints of the ECU subsheath. METHODS: The ECU subsheath was exposed on 12 fresh-frozen upper extremities. The tip of the ulnar styloid, the distal ulnar joint surface, and the proximal extent of the distal radio-ulnar joint were identified and dimensions measured. Subluxation of the tendon was then assessed with and without an intact subsheath in 9 specimens. The travel of the tendon was measured in pronation through supination and flexion before and after sectioning of the subsheath. RESULTS: The ECU subsheath is 8.9 mm (standard deviation [SD] = 0.8 mm) wide proximally and 9.0 mm (SD = 1.2 mm) distally. The distal ulnar insertion is 0.5 mm (SD = 0.8 mm) proximal to the tip of the styloid, and stretches 10.2 mm (SD = 2.7 mm) proximally. From maximum pronation to maximum supination and flexion, the ECU tendon traveled 3.32 mm (SD = 4.24) medially when the subsheath was intact and 5.42 mm (SD = 5.0 mm) after sectioning. The maximum depth of the ulnar groove was 2.5 mm (1.59-3.56 mm). There was no significant association between changes in ECU subluxation and the depth of the ECU groove (Spearman's rho = 0.25). CONCLUSION: The ECU subsheath is roughly 1 cm square stretching proximally from the ulnar styloid. ECU groove depth is not a significant independent predictor of tendon subluxation.
ABSTRACT
It is challenging to restore the clinically acceptable alignment of the distal radius after an acute on chronic fracture or after a secondary fracture occurring after malunion of a primary distal radius fracture. In cases of insignificant primary deformity, restoration to the primary deformity may suffice to obtain a successful clinical result. A borderline acceptable primary radial deformity can be unacceptable after the second injury, resulting in functional disability. If surgery is indicated, the surgeon must contend with both primary and secondary deformities to restore proper distal radius anatomy. We present our technique to correct both primary and secondary distal radius deformities through the new or secondary fracture plane.
