This cadaveric biomechanical study from Mayo Clinic uses an electromagnetic tracking system to quantify how much coronoid must be lost—with or without the radial head—before elbow kinematics become unstable, assuming intact collateral ligaments throughout.
When you see a coronoid fracture on imaging, the key decision point is whether it is a type II or type III (relative to the radial head equator) and whether the radial head is intact: a type II with an intact radial head can be managed non-operatively if ligaments are sound, but any type III fracture demands fixation regardless of radial head status, and a type II combined with radial head loss creates a joint that has surrendered 67% of its articular surface and is biomechanically unstable.
This cadaveric biomechanical study from Mayo Clinic uses an electromagnetic tracking system to quantify how much coronoid must be lost—with or without the radial head—before elbow kinematics become unstable, assuming intact collateral ligaments throughout.
When you see a coronoid fracture on imaging, the key decision point is whether it is a type II or type III (relative to the radial head equator) and whether the radial head is intact: a type II with an intact radial head can be managed non-operatively if ligaments are sound, but any type III fracture demands fixation regardless of radial head status, and a type II combined with radial head loss creates a joint that has surrendered 67% of its articular surface and is biomechanically unstable.