An 8-year-old boy who sustained a displaced supracondylar fracture of the humerus treated conservatively elsewhere returns two years later. His parents complain of the appearance of the arm. Examination shows the forearm deviating medially relative to the arm, with loss of the carrying angle. The most likely diagnosis is:

• A Cubitus varus from malunion of the supracondylar fracture ✓
• B Cubitus valgus from nonunion of the lateral condyle
• C Volkmann ischaemic contracture
• D Recurrent dislocation of the radial head

Explanation

Malunion of a supracondylar fracture with medial tilt of the distal fragment produces cubitus varus, the gunstock deformity, which is the commonest late complication of this fracture. It is chiefly cosmetic, since function is usually preserved, though late tardy posterolateral rotatory instability of the elbow has been described. Cubitus valgus instead follows lateral condyle nonunion or physeal arrest and carries the risk of tardy ulnar nerve palsy. Ischaemic contracture presents with fixed flexion and clawing, not pure angular deformity.

Reference: Tachdjian's Pediatric Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.