A 9-year-old boy sustained a completely displaced extension-type supracondylar fracture of the humerus two years ago that was managed conservatively without reduction. He now presents with his elbow deviated medially when the arm is extended. The most likely deformity is:
- A Cubitus valgus with tardy ulnar nerve palsy
- B Volkmann ischaemic contracture
- C Cubitus varus (gunstock deformity) ✓
- D Recurvatum deformity of the elbow
Correct answer: C. Cubitus varus (gunstock deformity)
Explanation
Malunion of a paediatric extension-type supracondylar fracture with residual medial tilt of the distal fragment produces cubitus varus, the gunstock deformity. It is chiefly cosmetic, though some patients develop tardy posterolateral rotatory instability. Cubitus valgus with tardy ulnar nerve palsy follows malunited fractures of the lateral condyle, not the supracondylar region, which distinguishes option A.
Reference: Apley's System of Orthopaedics and Fractures, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.