KIENBOCK DISEASE

DR. MANOJ BHAMASENIOR RESIDENT,

DEPT. OF ORTHOPAEDICS,S.P. MEDICAL COLLEGE,

BIKANER, INDIAmbhama@gmail.com

KIENBOCK DISEASE

• Synonyms: Avascular Necrosis of Lunate• First Described by Robert Kienbock in

1910; as “traumatic softening” of Lunate bone

• It is a painful disorder of wrist, due to avascular necrosis of carpal lunate, due to unknown cause

AETIOLOGY• Aetiology = unknown, but several cause have

been proposed• vascular compromise from repetitive trauma

causes microfracture & excessive stress on microscopic architecture (sports injury)

• Ulnar minus variant:- Individual having ulnar minus variance are at increased risk. Short Ulna increases shear force across the lunate Causes vascular insufficiency

EPIDIMIOLOGY

• Age= 15-40 (young individuals)• Sex= Men• Location= Unilateral, Dominant wrist

PATHOLOGYPathological changes proceed in 4 stages:-• Stage 1: Ischemia with naked eye or radiological

examination• Stage 2: Trabeculae Necrosis with reactive new

bone formation & increased radiographic density, but little or no distortion of shape.

• Stage 3: Collapse of Bone• Stage 4: Disruption of Radio-carpal congruence

& secondary OA

PATHOLOGY

• The natural history of Kienbock’s disease isProgressive Sclerosis

Fragmentation

Arthrosis

CLINICAL FEATURE• There may be history of trauma with wrist in

severe dorsiflexionThe lesion presents with1. Dorsal wrist pain:- Pain may be produced in

lunate region by axial strike/injury at distal end of middle finger

2. Swelling3. Decreased Grip strength4. Decreased range of motion; particularly in

extension. In later stage movement may be painful

IMAGING

• X-ray at first show no abnormality but bone scan may reveals increased activity

• Later x-ray may show either mottled or diffuse density of bone – to – osteoarthritic changes in wrist

• MRI Most reliable way of detecting the early change

CLASSIFICATION• Kienbock disease advances through 4

radiological stages• Stage I : Normal architecture; consistent with

Microfracture(Lunate abnormal on bone scan)

• Stage II : Lunate sclerosis without collapse• Stage III : Lunate collapse or Fragmentation &

proximal migration of capitate• Stage IV : Perilunate arthritis changes

TREATMENT

A ConservativeCasting of wrist for several wks ; for

early stages of disease ( St I or II, before sclerosis, fragmentation or collapse)

But- Unacceptable & IneffectiveB Operative• Surgery is only definitive treatment

Early Disease Stage I & II

• Unloading the Lunate*• 1. Ulnar lengthening• Transverse osteotomy at distal ulna

Distraction Cortical iliac graft Tightening of plate screw

Early Disease Stage I & II

2. Radial ShorteningIndication

– Negative ulnar variance– Lunate compression fracture without fragmentation or

flatteningProcedure

Transverse osteotomy 3” proximal to distal articulating surface

shortening of radius by 2 cm

fixing the bone with compression plate

In stage III1. Ulnar lengthening2. Silicon prosthesis

- silicon synovitis- foreign body cyst

3. Interacarpal fusion4. Lunate excision5. Arthrodesis Tri scaphe

Scaphocapitate

In stage IV

• Proximal carpal row resection• Wrist arthrodesis