KIENBOCK DISEASEDr.Rubeesh HassanD ortho,DNB ortho

INDRODUCTION KIENBOCK DISEAS is an isolated disorder of

lunate resulting from vascular compromise to the bone

Avascular necrosis/osteomalacia of lunate Dr Robert Kienbock –1910 He described step wise progression disease

from isolated proximal lunate involvement ,to fragmentation and collapse of lunate evolving to radiocarpal involvement with degenerative changes

AETIOLOGY Exact aetiology ? But it is likely multifactorial 1. Anatomical factors

2. Interrupted vascularity

3. Traumatic insults to lunate -repeated microtrauma

ANATOMICAL 1.Ulnar negative varience2. Three types of lunte morphalogies type 1 lunate has proximal apex type 2 and 3 more rectagular Type 1 seen in wrist with negative ulnar

varience Type 1 –higher rate3.Lower radial inclination All this anatomical factors seems to be results

in un equal load distribution through the radiocarpal joint.

INTERRUPTED VASCULARITY Vascularity to lunate is variable 3 major patterns of vascularity described  Y pattern I pattern X pattern In I pattern there is a single vessel

supplying the lunate ,which may increase risk of ostenecrosis.

In addition AVN of lunate has been linked to vascular insult caused by fracture,ligamentous collapse,primary circulatory collapse,systemic diseases and venous congestion.

Although there is no single definitive cause of kienbock disease ,a complex interplay of

vascular and anatomic variation ,combined with varying degrees of microtrauma and insults contribute to its development.

CLINICAL PRESENTATION Commonly affect men 20 to 40 years Symptoms can vary depending upon the

stage at initial presentation Pain localised to the radiolunate facet- pain is

classically insidious in onset Decreased wrist motion Swelling and decreased grip strength

Tenderness over the dorsal lunate and radiolunate facet

An effussion or bogginess overlying the radiocarpal join

Movements especially dorsiflexion is limited Average grip strength may decrease upto

50% of contralateral side In extreme case clenching of hand fails to

show the normal prominence of 3rd metacarpal—FINSTERS’S SIGN

Percussion over head of 3rd mc -tenderness

RADIOGRAPHIC IMAGING X Ray wrist PA and lateral view Negative in early in disease process Progressively shows increased lunate density Fragmentation Collapse Proximal migration of capitate widening of proximal carpal raw scaphoid rotation degeneratine changes in radio carpal bone

MRI

MRI SCAN MRI SCAN can detect early stages of disease

with increased signal uptake. In patients with perilunate dislocation or

ulnar impaction syndrome changes within the lunate may appears similar to the AVN ,however these changes are often focal and non progresive

CT SCAN CT scan characterise the lunate necrosis and

trabecular destruction once collapse has occurred.

STAGING

STAGE I Non specific intermittent wrist pain and

synovitis ,which may mimic a wrist sprain. Plain x ray films are either normal or shows

small linear compression fracture through lunate.

There is no collapse ,sclerosis or increased radiodensity of the lunate

Mri shows decreased signal uptake

STAGE II Characterised by increased swelling ,varying

degree of stiffness and progressive pain X ray shows lunate sclerosis with or without

compression fracture lines No evidence of collapse , lunate height is

maintained The remainder of the carpus remains without

degenerative changes

STAGE IIIA Is defined by continued sclerosis and collapse

of lunate Carpal height and intercarpal alignment is

preserved No scaphoid rotation Xray -lunate appears widened in AP view as

a result of the coronal plane collapse Scapholunate angle is preserved at -10 to

10degree

STAGE IIIB Collapse of lunate and charecteristic changes

of serrounding capitate and scaphoid Capitate migrate proximally and carpal

height become diminished Scaphoid flexes ,rotates resulting in DISI

pattern of instability

STAGE IV Progressive carpal collapse leading to

radiocarpal and midcarpal degenerative changes

Xray joint space narrowing ,subchondral sclerosis ,degenerative cysts and osteophyte formation

Symptoms have typically progressed to stiffness ,constant pain and swelling

TREATMENT Based on the stage at presentation Unload the lunate Revascularise the lunate Treat carpal instability and collapse with

salvage procedure

STAGE I Conservative treatment with 3 months

immobilisation is typically recommended for stage 1 desease

The patient should continue to be monitored and if symptoms or radiographs progress consider surgical management

STAGE II OR III WITH NEGATIVE ULNAR VARIENCE Goal in this stage is generally centered

towards unloading of lunte in an attempt to reduce intracarpal stress and allow revascularisation

Joint leveling procedures – Radial shortening osteotomies Ulnar lengthening proceduresRadial osteotomy is prefered over ulnar due to

less complication

STAGE II AND IIIA ULNAR NEUTRAL OR POSITIVE VARIANCE Revascularisation Osteotomies Cor decompression

REVASCULARISATION Principle – Transplantation of an

arteriovenous pedicle into normal and avascular bone results in new bone formation

Direct revascularisation allows the potential for salvage of the lunate and possible reversal of destruction of lunate through neoangiogenesis

Sources –distal radius pedicle graft with pronater teres

Vascularised pisiform graft Fourth and fifth extensor compartment artery

graft I,II or III dorasal metacarpal artery ransfer

OSTEOTOMIES Goal of this procedure to unload the lunate in

an attempt to decrease stress across radiolunate joint to allow revascularisation and prevention of disease progression

Capitate shortening osteotomies with or without capitohamate fusion

Radial closed wedge osteotomy—shift pressure from lunate by decreasing radioulnar inclination

COR DECOMPRESSION Metaphyseal decompression of radius and

ulna Decompression involve curettage of distal

radius /ulna through small cortical window Healing is due to local vascular response

STAGE IIIB Goal in this stage Stabilisation of carpus Prevent further collapse Decrease the load across

radiolunate joint Proximal row carpectomy Scaphotrapeziotrapezoid arthrodesis Scaphocapitate arthrodesis Grafting ,arthroplasty and interposition

PRC Is procedure that excises the

scaphoid ,lunate and triquetrium transfering load from the capitate directly to the lunate facet of the distal radius

STT AND SC ARTHRODESIS Is to correct fixed and rotated scaphoid and

stabilise midcarpal joint ,prevent further collapse

CONTROVERSIAL Lunate exction Silicon lunate prosthetic replaicement

STAGE IV Salvage procedures performed

PRC If mild degeneration WRIST ARTHRODESIS WRIST ARTHROPLASTY WRIST DENERVATION

SUMMARY Kienbock disease is defined by AVN of

lunate,with a predictable pattern of lunate collapse ,carpal changes , and degenaration resulting from an apparent combination of vascular,anatomical and traumatic insults.

Gaol of treatment is pain relief,motion preservation ,strength maintenance and function

There is no one procedure that consistently and reliably achieves this outcome

Gaol of treatment is pain relief,motion preservation ,strength maintenance and function

There is no one procedure that consistently and reliably achieves this outcome

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