Keinböck's disease

Etiology

 * Likely related to overuse and ulnar negative wrist variance.
 * Associated with sickel cell anemia, steriod use, gout, cerebral palsy.
 * Age: 2nd-5th decade.
 * Male > female

Anatomy
Lunate blood supply: single nutrient vessel, or poorly organized intraosseous anastamoses.

Clinical Findings

 * A painful and sometimes swollen wrist
 * Limited range of motion in the affected wrist (stiffness)
 * Decreased grip strength in the hand
 * Tenderness directly over the lunate (on the top of the hand at about the middle of the wrist)
 * Pain or difficulty in turning the hand upward

Diagnostic Tests

 * PA, Lateral, oblique views of the wrist. Generally demonstrate sclerotic lunate. Early films may be normal or minimal sclerosis. Evaluate for ulnocarpal impaction.
 * MRI: demonstrates avascular changes in the lunate.
 * Ct: demonstrates degree of fragmentation and collapse
 * Bone scan diagnostic at 48hrs (100% sensitive, 98%specific)

Classification and Treatment
Lichtman Classification (Lichtman DM, JBJS 59A; 899:1977).

Stage 1

 * The lunate appears normal on xray or there may be a nondisplaced fracture;
 * MRI demonstrates loss of signal consistent with osteonecrosis.
 * Treatment: spinting, activity modifications, NSAIDs
 * Consider ulnar lengthening or radial shortening for patients with negative ulnar variane.

Stage 2
Treatment: 4 + 5 extensor compartmental vascularized bone graft. (Moran CL, J Hand Surg 2005;30A:50).
 * Increased lunate radiodensity without loss of contour;
 * Lunate not collapsed.
 * Consider Proximal row carpectomy.

Stage 3A

 * Increased lunate radiodensity and fragmentation without loss of carpal height.
 * Treatment: 4 + 5 extensor compartmental vascularized bone graft. (Moran CL, J Hand Surg 2005;30A:50).
 * Consider scaphocapitate arthrodesis, or scaphotrapeziotrapezoid arthrodesis

Stage 3B
Lunate fragmentation with proximal migration of the capitate and rotation of the scaphoid.
 * Treatment: scaphocapitate arthrodesis, or scaphotrapeziotrapezoid arthrodesis
 * Consider Proximal row carpectomy

Stage 4

 * Lunate severely collapsed and fragmented, secondary arthritic changes in the wrist.
 * Treatment: Proximal row carpectomy.
 * Consider: scaphocapitate arthrodesis and scaphotrapeziotrapezoid arthrodesis.

Differential Diagnosis

 * Ulnocarpal impaction syndrome
 * Preiser's Disease

Complications

 * Degenerative changes in adjacent joints.
 * Stiffness, motion loss.
 * Weakness.
 * CRPS
 * Continued pain.
 * Instability.

Follow-up Care

 * Post-op: Volar splint in neutral, elevation.
 * 7-10 Days: Wound check, short arm cast.
 * 4 Weeks: Cast removed, xray wrist. Start gentle ROM, strengthening exercises. Functional activities.
 * 3 Months: Full activities, may resume manual labor if adequate strength has been achieved.
 * 6 Months and 1 year follow-up: x-rays, assess outcome