Comparison of Outcomes between Axial Radial and Axial Ulnar Carpal Injuries
Steven Shannon, MD1; Chelsea C Boe, MD1; Christine Oh, MD1; Alexander Y. Shin, MD2;
1Mayo Clinic, Rochester, MN, 2Division of Hand Surgery, Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN
Introduction: Axial carpal injuries are rare entities where a traumatic force transmits through the intermetacarpal space, dissociating the carpometacarpal joint and disrupting the distal carpal row in an axial radial or axial ulnar pattern. Previous literature has not demonstrated differences in outcomes with regards to injury pattern or true axial vs. compressive crush injury mechanism. The objective of this study was to distinguish the role of mechanism and delineate specific features of these injuries that portend poor prognosis.
Methods: Carpal injuries treated at a single level I trauma center between January 1, 1990 and December 31, 2014 were reviewed to identify axial carpal injuries. Demographics, mechanism, injury pattern, surgical procedures performed, length of immobilization, complications including compartment syndrome and need for subsequent procedures were recorded. Mayo wrist scores were calculated at final clinical follow up.
Results: Thirty-seven patients over 25 years were identified with axial carpal injuries, with 20 wrists experiencing an axial radial injury and 17 wrists an axial ulnar injury. All wrists were managed surgically with K-wire fixation. Five patients were diagnosed with compartment syndrome and 10 patients required free tissue transfer for coverage of severe soft tissue defect. Axial radial injuries were significantly more likely to be open injuries. No patient experienced an excellent outcome and 20 of the 37 patients experienced a poor outcome defined by Mayo Wrist Score. Of the variables evaluated, only axial radial pattern was identified as predictive of poor outcome with univariate analysis demonstrating 6 times increased risk and multivariate analysis demonstrating 15 times increased risk of a poor outcome compared to axial ulnar injuries. Degree of soft tissue injury, nerve injury and true axial vs. compressive mechanism were not associated with worse outcome.
Discussion and Conclusion: Axial carpal injuries result in consistently poor outcomes, regardless of mechanism. In contradiction to previously published series, we did not find that severity of soft tissue injury or nerve injury were associated with worse outcome, though we did find axial radial patterns to be significantly associated with a poor outcome measured by Mayo Wrist Score. This may be due to the lever arm of the thumb and pronated position of radial column of the carpus resulting in greater transmission of force and more severe carpal injury.
Back to 2019 ePosters