Distal defect of the humerus, a possible normal variant: a case report

Area of Science:

• Orthopedic imaging
• Skeletal anatomy

Background:

• Normal variants of bone structures are frequently observed on plain radiographs.
• Accurate identification of these variants is crucial for differential diagnosis.

Observation:

• A 14-year-old female presented with intermittent elbow pain without trauma.
• Radiographs revealed a well-defined osteolytic lesion with a sclerotic rim in the distal humerus.
• MRI showed specific signal intensities on T1 and T2 fat-suppression sequences, with no bone edema.

Findings:

• The imaging characteristics suggested a normal bone variant rather than osteochondritis dissecans or a neoplastic process.
• The lesion was continuous with the subarticular bone, a key feature differentiating it from other pathologies.
• The association between the patient's elbow pain and the identified lesion was inconclusive.

Implications:

• This case highlights a potential anatomical variant that can mimic pathological bone lesions.
• Radiologists and orthopedic surgeons should consider this variant in the differential diagnosis of distal humerus osteolytic lesions.
• Further understanding of such variants can prevent misdiagnosis and unnecessary interventions.