In addition to fracture, any process resulting in an elbow joint effusion may also demonstrate an abnormal fat pad sign.
Increased intracapsular fluid is also seen in several conditions other than fracture and this produces the abnormal fat pad sign.
In these instances, history and clinical examination in addition laboratory results (WBC, ESR, CRP) will guide the provider in determining whether to treat the condition as an occult fracture or continue workup for other pathology.
[2] The posterior fat pad is normally pressed in the olecranon fossa by the triceps tendon, and hence invisible on lateral radiograph of the elbow.
[3] When there is a fracture of the distal humerus, or other pathology involving the elbow joint, inflammation develops around the synovial membrane forcing the fat pad out of its normal physiologic resting place.