Keinböck's disease

Etiology / Epidemiology / Natural History

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

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

Diagnositc 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 / 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: 1Yr: 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