Introduction: Better understanding of disruption of bony and ligamentous constraints of the radiocapitellar joint in complex capitellum fracture is essential for optimizing the surgical care and outcome. This report highlights the need for modification in surgical fixation technique to address an unusual variant of this rare injury. Case Report: We report a three-part capitellum fracture pattern with a Y-shaped split of distal humerus with a sheared anterior fragment and a single, large, non-articular posterolateral fragment in a young male patient. Articular fragment was fixed with two countersunk anterior-distal to posterior-proximal oblique screws. Additional screw was used to fix the posterolateral fragment to prevent posterolateral rotational instability. Mayo elbow performance score was 95 with no rotational instability at 2 years follow-up. Conclusion: Additional fixation of posterolateral fragment in this three-part variant of Bryan and Morrey Type IV capitellum fracture ensured rotational stability and good function. Keywords: Complex capitellum fracture, anterior-posterior fixation, elbow posterolateral rotatory instability, posterolateral capitellum fracture.