· Predisposed in individuals engaged in manual labor with repeated or single episode of trauma
· Frequency
o Usually affects men aged 20-40 yrs.
o Mostly unilateral
o More often in right wrist
· Pathophysiology
o Vascular impairment due to acute or chronic injury
( Exact cause is unknown)
o Lunate develops osteonecrosis due to loss of blood supply, causing pain and stiffness in the wrist
o In late stages, the bone collapses eventually leading to degenerative changes and osteoarthritis in the radiocarpal joint
· Clinical findings
o Progressive pain
o Soft-tissue swelling of wrist
Imaging findings
o The disease can be staged based on radiographic findings
** Lichtman's Radiographic Classification of Kienbock's Disease
· Stage I - Normal radiograph
· Stage II - Sclerosis of lunate with possible decrease of lunate height on radial side only
· Stage IIIa - Lunate collapse, no scaphoid rotation
· Stage IIIb - Lunate collapse, fixed scaphoid rotation
· Stage IV - Degenerative changes around the lunate
§ The disease may also be associated with negative ulnar variance
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmMcCf7ND_psHVjdtGdR3C-e3F16vxZn2qCwvA4G4pEm5fB5LE6gU8LBLQevHyuOulIJ37vET_-KA4VQp3rHX6BX2-zK3mIb0SEBoB3gXkt38M20ko04hldfdi8pO9EfYuUQC0uDUIFIo/s400/cow175arr.jpg)
and collapse of the lunate (blue arrows) in Kienbock's Disease (Kienbock's Osteomalacia)
o Bone scan and MRI may be helpful early in the course of the disease when there are minimal radiographic findings.
Treatment:
** Initial therapy is conservative management
** Anti-inflammatory medications and splinting or casting
** Operative treatment is based on the stage of the disease and may involve
1-Revascularization procedures
2-Ulnar lengthening or radial shortening
3-Fusion or excision of carpal bones