A 30-year-old falls directly on the outstretched hand. X-ray shows a perilunate dislocation without fracture. According to Mayfield's progressive perilunar instability pattern, this injury corresponds to which stage?

• A Stage I — scapholunate dissociation
• B Stage II — capitate dislocates dorsal to the lunate ✓
• C Stage III — triquetrum dissociates from the lunate
• D Stage IV — lunate dislocates palmar, pushed out of the cup

Explanation

Mayfield's four-stage perilunar instability describes progressive failure of carpal ligaments with increasing dorsiflexion and ulnar deviation load. Stage I: scapholunate ligament failure (scapholunate dissociation). Stage II: capitolunate joint failure; the capitate (and remainder of carpus) dislocates dorsally relative to the lunate — this is perilunate dislocation without fracture. Stage III: lunotriquetral ligament failure. Stage IV: the lunate itself is pushed palmarly out of the lunate fossa — this is lunate dislocation. Hence a perilunate dislocation without fracture is Stage II.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.