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 Evaluation

• Dorsal wrist pain +/- swelling/warmth
• Tenderness over the radiolunate joint
• Decreased ROM.
• Decreased grip strength

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

• Increased lunate radiodensity without loss of contour;
• Lunate not collapsed.
• Consider Proximal row carpectomy.

Treatment: 4 + 5 extensor compartmental vascularized bone graft. (Moran CL, J Hand Surg 2005;30A:50).

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. Cock-up wrist splint prn / for light duty work. No heavy manual labor
• 3 Months:Full activities, may resume manual labor if adequate strength has been achieved.
• 6 Months:
• 1 Yr: fo,,ow-up xrays, assess outcome

References

• Weiss AP, Weiland AJ, Moore JR, Wilgis EF: Radial shortening for Kienbock's disease. J Bone Joint Surg Am 1991;73:384-391.
• Morgan WJ, JAAOS 2001;9:389