Risk Factors for Loss of Reduction After Open Reduction and Internal Fixation of Isolated Olecranon Fractures in Adults.

Background: We sought to determine whether any relevant patient, fracture, surgical, or postoperative characteristics are associated with loss of reduction after plate fixation of isolated olecranon fractures in adults.

Methods: Patients who underwent open reduction and internal fixation of an olecranon fracture at our institution over an 11-year period were analyzed. Electronic patient charts and radiographic images were reviewed to gather patient, fracture, surgical, and postoperative data. Statistical analysis to explore the differences between groups was performed.

Results: Seven of 96 patients experienced a loss of fracture reduction diagnosed at a median of 19 days after their initial surgery (range: 4-116 days). The radiographic mode of failure of all patients who lost reduction was proximal migration of the proximal fracture fragment with or without implant failure. The group that lost reduction had a significantly smaller proximal fragment (14.2 vs 18.6 mm), a higher incidence of malreduction with a persistent articular step-off greater than 2 mm (6/7 vs 14/89), a greater distance between the most proximal screw and the olecranon tip (19.8 vs 13.5 mm), a higher proportion of constructs with screws placed outside of the primary plate (4/7 vs 14/89), and a higher proportion of patients that were not immobilized postoperatively (3/7 vs 8/89).

Conclusions: Our results suggest anatomical reduction at the articular surface and adequate fixation of the proximal fragment are key factors in maintenance of reduction, with smaller proximal fragments being at higher risk for failure. A period of postoperative immobilization may decrease the risk of loss of reduction.