This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bone Tumour, Subject name: Orthopaedics
Shepherd crook deformity is seen in? 
Select and explain. 
A. Fibrous dysplasia, B. Non ossifying fibroma, C. Adamantinoma, D. Fibrous cortical defect
A: Fibrous dysplasia
Answer: A: Fibrous dysplasia 
Explanation: ANSWER: (A) Fibrous dysplasiaREF: Sutton's 7th ed p. 1131Fibrous dysplasia in the femur, deformity due to softening, expansion and fracture gives an appearance likened to a 'shepherd's crook' and discrepancies in limb length result. Lesions are well defined and may be expanded with well-defined margins. These may be lucent, dense or a mixture of the two, with small flecks of density due to ossification