Review Question - QID 211578

The patient has sustained a lunate dislocation with subsequent ischemia, which is likely transient. Transient ischemia after lunate and peri-lunate dislocations is usually benign and self-limiting.

Lunate and perilunate dislocations typically result from high energy mechanisms and are commonly missed on initial presentation. Acute injuries require emergent closed reduction and splinting with close observation for acute carpal tunnel symptoms. This is usually followed by open reduction internal fixation with a ligamentous repair. The ischemia and increased radiodensity that develops in some patients does not typically follow the clinical and radiographic progression associated with avascular necrosis, Kienböck’s disease.

White et al. reported on the transient vascular compromise of the lunate after fractures and fracture-dislocations of the wrist. In their series of 24 patients who sustained dislocation or fracture-dislocation of the carpus, 3 (12.5%) developed an increase in radiodensity within one to four months of injury. The radiographic appearance of the lunate returned to normal in two of the three patients with partial resolution in the third and stable appearance 8 years after injury. None progressed to the classic signs of avascular necrosis. The authors recommend nonoperative treatment with observation.

Stansbury et al. reviewed perilunate dislocations and perilunate fracture-dislocations. They recommend careful radiographic inspection in trauma victims with wrist pain. Carpal height and carpal arcs should be assessed on the AP while collinearity of the radius, lunate and capitate should be maintained on the lateral. The authors note the development of lunate transient ischemia should not be overinterpreted, as it is likely to resolve.

Forli et al. report on long-term functional outcomes after perilunate dislocations and transscaphoid perilunate fracture-dislocations. The authors retrospectively reviewed 18 patients with a minimum of 10-year follow-up. The presence of arthritis identified on radiographs and static carpal instability did not cause reduced function. They conclude signs of posttraumatic arthritis after these injuries increase progressively, but are well tolerated at an average of 13-years after injury.

Figure A demonstrates the volar dislocation of the lunate. Note the “spilled teacup sign” and loss of collinearity of the radius, lunate and capitate. Figure B demonstrates a radiodense lunate consistent with ischemia.

Incorrect Answers
Answer 1: Temporary scaphotrapeziotrapezoidal pinning is a treatment for adolescents with radiographic evidence of Kienböck’s disease and progressive wrist pain.
Answer 3: Proximal row carpectomy is a treatment for significantly progressed Kienböck’s disease. In addition, PRC can be used to treat chronic perilunate injuries (defined as >8 weeks after initial injury).
Answer 4: Capitate shortening osteotomy is a treatment for Lichtman stage II and III Kienböck’s disease.
Answer 5: Immobilization is the initial management for Lichtman stage I Kienböck’s disease, but not indicated for transient ischemia. A majority of patients with Kienböck’s disease will undergo further degeneration despite nonoperative measures.