Review Question - QID 219954

The patient is a young, skeletally immature male with radiographic evidence of stage I Kienböck disease, or osteonecrosis of the lunate. This should initially be treated conservatively with wrist immobilization and anti-inflammatories (Answer 1).

Kienböck disease is an avascular necrosis of the lunate that eventually leads to progressive wrist pain and abnormal carpal motion. The diagnosis can be made with wrist radiographs in advanced cases, but these may be negative and require MRI for detection of early disease. Though the pathophysiology is multifactorial, it is thought to be caused at least in part by alterations in vascular supply to the lunate and numerous biomechanical factors, including decreased radial inclination and ulnar negative variance, which leads to increased radial-lunate contact stresses. The Lichtman classification (Illustration A) can be used to classify the disease and guide treatment, with stage II disease reflected by sclerotic changes of the lunate visible radiographically and indicating the need for a joint-leveling or revascularization procedure. Patients with late-stage III changes evidenced by lunate collapse and fixed compensatory scaphoid rotation are best treated with either a PRC or fusion procedure.

Rioux-Forker et al. provide a review article on Kienböck disease or osteonecrosis of the lunate. The authors note that the exact mechanism(s) of Kienböck disease has/have not been fully elucidated, though it is thought to be an interplay between altered vascular perfusion, repetitive microtrauma, variable lunate anatomy, altered loading and kinematics, and potential systemic disease. They conclude that there is a tremendous need for a randomized, multicenter evaluation of the various treatment options with standardized outcome measures.

Keith et al. reviewed the long-term outcome of non-surgically managed Kienböck disease. The authors included thirty-three patients (33 wrists) with conservatively treated Kienböck disease and found that range of motion, grip strength, and DASH scores deteriorated between stages 2 and 4, leading them to conclude that Kienböck disease is progressive and does pass through the various stages described by Lichtman, with progression able to be monitored clinically by the Disabilities of the Arm, Shoulder, and Hand score and the loss of flexion of the wrist.

Innes et al. provide a systematic review of the treatment of Kienböck's disease in its early and late stages. The authors note that grip strength was significantly improved in early-stage patients after radial osteotomy and vascularized bone grafting (VBG) and for all late-stage patients, except among those managed non-surgically. They concluded that based on retrospective data from uncontrolled studies, no active treatment is superior in the treatment of Kienböck's disease and there are insufficient data to determine whether the outcomes of any intervention are superior to placebo or the natural history of the disease.

Figures A and B represent a PA radiograph and a T1-weighted coronal MRI sequence, respectively showing normal radiographically appearing bones of a skeletally immature 7-year-old with decreased lunate signal in the T1-weighted image (red arrow) indicative of stage I disease and obvious ulnar negative variance. Illustration A depicts the Lichtman classification, which helps to guide treatment.

Incorrect Answers:
Answer 2: A distal radius core decompression, radial shortening, and/or ulnar lengthening (not ulnar shortening) would be indicated in stage II or IIIA disease without fixed compensatory scaphoid rotation.
Answers 3-5: A PRC or fusion procedure would be indicated in stage IIIB or C disease, not stage I disease in a skeletally immature patient.