wrist

Prepared by:

Dr.Juma Khan Rasekh MS Ortho.

Kabul afghanistan 2014

Anatomy of the Wrist

Carpal bones tightly linked by capsular and interosseous ligaments.

Capsular (extrinsic) ligaments originate from the radius and insert onto the carpus.

Interosseous (intrinsic) ligaments traverse the carpal bones.

The lunate is the key to carpal stability.

Ligaments

volar - thick, strong

dorsal - thinner, fewer

unique function

extrinsic

intrinsic

Volar

Ligaments

MUN ORTHOPEDICS

Wrist ligaments

Dorsal Extrinsic Ligaments

DIC

DRC

What is lunate (Luna=moon

Lunate

Connected to both scaphoid and triquetrum by strong interosseous ligaments.

Injury to the scapholunate or lunotriquetral ligaments leads to asynchronous motion of the lunate and leads to dissociative carpal instability patterns.

Proximally articulates with

radius and TFCC

•Distally articulates with

capitate alone in 1/3 of

cases

•In the rest, articulates with

the hamate as well

Lunate arterial supply

Blood Supply Volar Aspect Dorsal aspect

Least vascular area of the lunate: subchondral bone adjacent to the radius

majority of lunates have both dorsal & palmar

vessels & are thus as well vascularized as the other carpal bones;

- neither singleintraosseous nor extraosseous disruption alone will cause avascular necrosis in these bones because of the rich external and intern

al anastomoses;

Blood supply to the lunate may be a key factor in pathogenesis. Three patterns of extraosseous blood supply has been described for lunate. Multiple vessels, one volar and one dorsal vessel each and a single dorsal blood vessel in 7%. In addition 31% of cases showed single path of intraosseous supply through the bone with no significant arborization. Lunate with a single blood vessel supply may be at risk for avascular necrosis in presence of trauma.

Proximal portion of lunate is a terminal perfusion zone dependent on intraosseous retrograde blood supply. In Kienbock disease, the pathoanatomical changes show zone of necrosis in the proximal portion, zone of reparation in the middle layer with fibrovascular reparative tissue and zone of viability in the distal portion. Disruption of venous outflow has also been thought to be a cause of Kienbock disease.

20% of lunate are supplied by a single artery and are therefore are at risk for avascular necrosis

Vascular Anatomy of the Lunate The literature suggests that 7% to 26% of lunates ma

y have a single volar or dorsal blood supply (type 1) and are therefore vulnerable to the development of AVN by disruption of extraosseous vessels alone (20). In other lunates, an extensive extrinsic blood supply or robust intraosseous connections require extensive disruption of extraosseous or intraosseous vasculature if AVN is to develop.

The anatomy and vascularity of the lunate:

considerations applied to Kienböck's disease.

Hand Unit and Upper Extremity, Department of Orthopedic Surgery, Hospital de la Santa Creu i Sant Pau, Autonomous University of Barcelona, Barcelona, Spain. clamasg@hsp.santpau.es

Abstract

PURPOSE:

The purpose of this study was to assess the anatomy and vascularity of the lunate.

METHODS:

they studied 27 cadaver upper limbs using latex injection and the Spalteholz technique. they investigated the blood supply to the lunate.

RESULTS

The nutrient vessels entered the lunate through the dorsal and volar poles in all the specimens. The dorsal intercarpal and radiocarpal arches supply blood to the lunate from a plexus of vessels located directly over the lunate's dorsal pole. Vessels entered the dorsal aspect of the lunate through one to three foramina. One to five nutrient vessels were observed entering the volar pole through various ligament insertions, including the ligament of Testut-Kuentz (radio-scapho-lunate (RSL) ligament) and the radiolunate triquetrum ligament (or dorsoradial carpal ligament) and ulnar lunate triquetral ligament.

Volar

Ligaments

Dorsal Extrinsic Ligaments

DIC

DRC

CONCLUSIONS:

The lunate had consistent dorsal and palmar arteries entering the bone in all the specimens. The blood supply and foramina number is greater in the volar pole of the lunate than the dorsal pole. The lunate blood supply comes from different ligaments. In the etiopathogeny of Kienböck's disease it is possible that an acute or chronic, traumatic or non-traumatic injury of the vessel bearing ligaments, particularly because of their structure and the location of the RSL ligament, may have an important role in the appearance of lunate necrosis.

Distal Radius

Facets

Lateral (46%) scaphoid

Medial (43%) lunate

Inferior disk (11%) triquetrum

Articulations and ROM Distal Radioulnar joint

Supination and Pronation – 80-90o

Ulna moves posteriorly and laterally with pronation

Radiocarpal joint (and Ulnocarpal joint)

Flexion (80-90o) and Extension (75-85o)

Radial (20o) and Ulnar (35o) Deviation

Intercarpal joints

Gliding

Soft tissue of Wrist

Ligaments

Covered by a fibrous capsule

Radial and ulnar collateral

limit ulnar and radial deviation; collectively limits flexion and extension

Intercarpal and Carpometacarpal

Soft tissue of Wrist Ligaments Dorsal – limits flexion

Dorsal Radiocarpal

Palmar - limit extension Transverse carpal ligament

Palmar radiocarpal Multiple divisions

Palmar ulnocarpal ligament Multiple divisions

Soft tissue of Wrist Cartilage

Triangular Fibrocartilage Complex – TFCC “Meniscus” between ulna and

triquetrum

Ulnar collateral ligament and palmar ulnocarpal ligaments have attachments

Compressed with Pronation and Extension

Compressed with Ulnar deviation

KIENBOCK’S DISEASE

KIENBOCK’S DISEASE

KIENBOCK’S DISEASE

HISTORY

DEAFINATION

ETIOLOGY

CLASSIFICATION

DIAGNOSIS

TREATMENT

OUTCOME

DEAFINATION

Idiopathic osteonecrosis of lunate

Stress or compression fracture of the lunate Disruption of blood supply with collapse and secondary fragmentat

ion

Pain and stiffness of the wrist in the ABSENCE of TRAUMA

Scapholunate Dissociation

Diagnosis often missed

Pain, swelling, and decreased ROM

Pressure over scaphoid tuberosity elicits pain

Greatest pain over dorsal scapholunate area, accentuated with dorsiflexion

X-ray shows widening of scapholunate joint space by at least 3 mm

History AVN of the lunate, or lunatomalacia, was first describ

ed in cadaveric specimens by Peste in 1848 . He believed that the lunate changes were posttraumatic, secondary to fracture.

Kienböck described the characteristic findings of lunatomalacia in an x-ray in 1910. Six years later, Kienböck's name was ascribed to lunate AVN when Speed first termed the condition Kienböck's disease in his textbook (1916) .

HISTORY

First described by Peste in 1843

Described as lunatomalacia by Kienbock (1910)

Traumatic rupture of the ligaments and vessels

around the lunate produced lunate fracture with

subsequent collapse.

The etiology of Kienböck's disease

Multiple factors contribute to the necrosis

of the lunate

Extrinsic Factors

Intrinsic Factors

Extrinsic Factors Ulnar Variance

Geometry and BIOMECANICS of the Distal Radius

Trauma

Instability

Fracture

Ulnar Variance

Relationship of the distal articular surfaces of the

ulna and the radius seen on a PA X-ray of the

wrist

Ulnar Variance

Ulnar Variance

Ulnar Variance

Hulten noted that 74% of patients with Kienbock’s

had negative ulnar variance

In a normal population:

61% neutral ulnar variance

23% negative

16% positive

Normal ulnar variance 80% of load goes to the radius

Positive ulnar variance in +2.5mm of ulnar variance 60% of load goes to radius while 40% g

oes though ulna

leads to ulnar sided wrist pain from increased impact stress on the lunate and triquetrum

associated conditions include

ulnar impaction syndrome

SLD

TFCC tears

lunotriquetral ligament tears

Negative ulnar variance in -2.5mm of ulnar variance, 95% of load goes through radius and 5

% of load goes through ulna

associated with Kienbock's disease

•Method to determine ulnar variance

• requires PA radiograph w/ wrist in neutral supination/pronation and zero

rotation

• from the PA view draw two lines one tangential to the articular

surface of the ulna and perpendicular to its shaft

• the other tangential to the lunate fossa of the radius and

perpendicular to its shaft.

• measure the distance between these two lines.

• If the ulnar tangent is distal to the radial tangent there is positive

ulnar variance, if it’s proximal there is negative ulnar variance.

Normal is 0mm.

Ulnar Variance

BIOMECANICS

90.3% of the radio-ulno-carpal force is transmitted

to the radius:

◦ 61% through radioscaphoid joint and

◦ 39% through radiolunate joint

9.7% through TFCC

BIOMECANICS

Load through the lunate depends on:

◦ Amount of bone that is not covered by distal radius and

◦ Ulnar variance

Schuind et al J Biomechanics, 1995

LUNATE BONE

BIOMECANICS Nutcracker effect

◦ Lunate articulates with the rigid capitate and radius on

one side and the elastic TFCC on the other

LUNATE AT RISK Ulnar negative variance

Single extra-osseous nutrient vessel

Poor intra-osseous anastomosis

Carpal Angles

Carpal Angles

47 degrees(30-60) 0 degrees(+/- 15)

Carpal Height

L2/L1 = 0.54+/-0.03

REVISED CARPAL HEIGHT

RATIO =L2/CAPITATE

LENGTH = 1.57 +/- 0.05

Lunate Fracture

SCAPHOLUNATE DISSOCIATION

SCAPHOLUNATE DISSOCIATION

EXAM Watson’s test (scaphoid shift test)

Scaphoid shuck test

Pain/swelling over dorsal wrist, prox row

DIAGNOSIS Plain films: >3mm difference on clenched fist

Scaphoid ring sign

Intrinsic Factors Anatomy of the Lunate

Arterial Insufficiency

Venous Stasis

Vascular theory

◦ Primary circulatory problems,

e.g. Sickle cell disease/ raised venous

pressure

Mechanical theory

◦ Excessive mechanical loads cause

repeated microfractures and collapse

◦ Role of trauma

Kienbock Disease

Stage I – IV

Stage I: MRI only

Stage II: Sclerosis

Stage III: Some collapse

Stage IV: Total collapse

Lichtman's Radiographic Classification of Kienbock's Disease

Stage I - Normal radiograph

Stage II - Sclerosis of lunate with possible decrease of lunate height on radial side only

Stage IIIa - Lunate collapse, no scaphoid rotation

Stage IIIb - Lunate collapse, fixed scaphoid rotation

Stage IV - Degenerative changes around the lunate

stage I

The radiographic changes that occur in Kienböck's disease tend to follow a pattern of progression beginning with fractures in the necrotic subcortical trabeculae of the lunate due to forces applied to it through the capitate

stage II

Absence of bone remodeling and the collapse of trabeculae lead to a relative increase in radiodensity in the lunate

stage IIIa

With time, lunate collapse follows

stage IIIb

Collapse progresses until the joint compressive forces are attenuated by redistribution to the proximal scaphoid and triquetrum. The ulnar aspect of the lunate, which overlies the triangular fibrocartilage, is usually less involved than the portion articulating with the lunate fossa, due to the difference in compliance between the two surfaces. Loss of interosseous ligament connections due to fragmentation of bone may result in further carpal collapse and loss of normal intercarpal relationships

Loss of interosseous ligament connections due to fragmentation of bone may result in further carpal collapse and loss of normal intercarpal relationships

Bain & Begg Arthroscopic classification

Based on number of nonfunctional articular surface.

Based on number of nonfunctional articular surface.

0- Articular surfaces are normal

1- Proximal surface of lunate abnormal

2A- Proximal surface of lunate and lunate fossa of Radius abnormal.

2B- vertical fracture of lunate.

3- Lunate fossa of radius and proximal and distal surfaces of lunate abnormal.

4- Lunate fossa of radius and proximal and distal surfaces of lunate and the proximal surface of capitate abnormal.

Schmitt and Lanz MRI patterns

N- Normal signal

A- Marrow edema with viable and intact bony trabeculae

B- Early marrow necrosis with fibro-vascular reparative tissue

C- Necrotic bone marrow with collapse

Pathological phases of Kienbock disease are;

Early vascular phase- Ischaemia, necrosis, revascularization

Intermediate osseous phase- Sclerosis, subchondral collapse, coronal fracture, remodelling

Late chondral phase- Subchondral collapse, articular surface collapse, degeneration of opposing articular surface.

Classification: Lichtmann Staging

Stage 1 Normal Xray,MRI/Bone scan+ve

Stage 2 Abnormal density

Stage 3a lunate collapse

Stage 3b carpal collapse

Stage 4 osteoarthritis

Staging

Initial symptoms

Initial symptoms include dorsal central pain, swelling, and limited wrist motion. These symptoms may be present for many months before the patient seeks medical attention.

Symptoms include dorsal wrist pain, weakness, and loss of wrist motion affecting extension more than flexion. Patients may also note dorsal wrist swelling and, on occasion, symptoms of carpal tunnel syndrome

Evaluation History

Examination

X-Ray Findings

Bone Scan

Computed Tomography Scan

Magnetic Resonance Imaging

Diagnostic Arthroscopy

DIAGNOSIS

Diagnosis

radiographic

young adults

pain , stiffness . tenderness

marked loss of grip strength

IMAGING

� PA X ray

� MRI

� CT

More common in men

Peak incidence: 18-40 yrs

Most patients are involved in heavy manual labour

Typically unilateral

CLINICAL PRESENTATION

Insidious onset wrist pain

Beware of making a diagnosis of wrist sprain

Pain is aggravated with activity, relieved with rest

Weakened grip strength

Slightly reduced flexion and extension

Diagnosis

early - Xrays normal

MRI

Bone Scan

CT

Diagnosis

AVN on MRI - low signal on T1 & T2

MRI helps to differentiate Kienbocks from other causes of radiolucency in lunate

Bone scan : increased uptake

MRI

Choice of surgery depends on the stage of disease, range of movement of wrist, ulnar variance, shape of sigmoid notch and the presence of coronal fracture of lunate.

Treatment is mainly based on the stage of disease.

Treatment recommendations based of Lichtman’s classification

I – Immobilization

II &IIIA with negative ulnar variance- Radial shortening

II &IIIA with positive ulnar variance- Lateral wedge osteotomy of radius or Capitate shortening

IIIB- Proximal row carpectomy or triscaphe fusion

IV- Wrist arthrodesis

Treatment

Radiographic stage

Experience of the surgeon,

Desires and activity level of the patient,

Anatomic variation of the ulna,

And other radiographic, arthroscopic, or surgical findings such as disruption of lunate articular cartilage or extruded fracture fragments

In the early stages, efforts should be made to salvage the lunate and prevent loss of normal architecture.

In the later stages, efforts should be made to restore that architecture.

In the end stage, normal architecture must be sacrificed to restore function.

Treatment Nonoperative Treatment

Surgical Treatment

Nonoperative Treatment is based on the principle of diminishing the forces responsible for the usual progression of lunatomalacia from ischemia to collapse and arthrosis

Hulten believed that early disease should be treated with immobilization for periods as long as 4 months

Kristensen recently compared immobilization with no treatment He found immobilization to be ineffective, with progressive lunate collapse in all wrists

In a recent long-term review of 25 cases treated by immobilization

, six patients had no pain,

but 14 had daily problems

seven had to change their occupation after a mean follow-up of 8 years

They concluded that nonoperative treatment of Kienböck's disease was ineffective. In most series, progressive collapse and continued pain have been the usual result of casting .

At present, immobilization is reasonable primarily in stage I disease, when spontaneous revascularization may possibly allow the lunate to heal. If pain persists, efficient treatment must be based on surgical methods

Surgical Treatment Surgical treatment of Kienböck's disease can be divid

ed into three broad categories:

1: Mechanical (lunate unloading),

2: Biologic (lunate revascularization),

3: Salvage therapy

Mechanical

Lunate Unloading

it would be reasonable to consider the use of external fixators or midcarpal pinning for a similar period.

Joint Leveling An osteotomy to realign the radiocarpal joint by

shortening of the radius

Or lengthening the ulna

Radial Shortening Radial shortening is generally preferred:

: No graft is needed,

:And the plate may be placed anteriorly where it is well covered by soft tissue and therefore less symptomatic.

An osteotomy in the metaphyseal region heals faster

Extraarticular nature of the procedure

Ulnar Lengthening

Ulnar lengthening is nearly equivalent biomechanically to radial shortening—2.5 mm of lengthening results in a marked increase in ulnocarpal load and diminution in radiolunate force

Capitate Shortening

Capitate shortening is a highly effective method for reducing lunate loading in cases in which a joint leveling procedure cannot be performed.

It does effectively unload the lunocapitate and radiolunate joints,

The method may be combined with a CH fusion (107) and has been reported to provide good results in patients with early Kienböck's disease with minor architectural changes in the aseptic lunate, no arthritic changes, and no ulnar-minus variance (107). The procedure may be performed as an adjunct to lunate revascularization

Intercarpal Fusions

Intercarpal fusion is another method used to diminish lunate loading or prevent or correct carpal collapse associated with stage III changes. Two limited fusions have been documented to unload the lunate (STT and SC) (Fig. 7). Another intercarpal fusion between CH has been reported to provide symptomatic relief in Kienböck's disease (108) but by an unknown mechanism, as its arthrodesis has no effect on carpal loading.

Scaphotrapeziotrapezoid STT arthrodesis has been applied for the treatment

of Kienböck's disease and has been demonstrated to diminish lunate compressive forces

STT Fusion

Clinical studies have demonstrated that STT arthrodesis may provide good clinical results in Lichtman stage III

Scaphocapitate

SC arthrodesis is another procedure that is effective in modestly reducing lunate loading. A decrease of radiolunate joint force of approximately 10% to 12% has been measured, along with an 11% reduction in lunocapitate and ulnolunate forces

Capitate-Hamate CH arthrodesis has been suggested by Chuinard for t

he treatment of Kienböck's disease . Clinical reports of the method suggest that it is effective in alleviating patient symptoms

Lunate Revascularization Lunate revascularization is an example of one form o

f therapeutic intervention, termed surgical angiogenesis. It is defined as the surgical transfer of vessels or well-vascularized autogenous tissue, used alone or augmented by simultaneous application of vasculogenic cytokines

In orthopedic practice, both implanted AV bundles and vascularized pedicle or free bone flaps (grafts) have been used in the specific case of osteonecrosis

Vascularized Bone Grafts

Vascularized pedicle bone grafts have been used in cases of aseptic necrosis of the scaphoid proximal pole nonunion fragment, AVN of the scaphoid (Preiser's disease), and Kienböck's disease.

applied to carpal pathology have been described by many investigators and have been transposed from the pisiform, palmar and dorsal radial metaphysis, second metacarpal head, the metaphysis of the radil or ulnar shaft

To be successful, all vascularized pedicle bone grafts must have a pedicle of sufficient length to reach the recipient site without tension. Second, the vascular pedicle should ideally include nutrient vessels that supply both cortical and cancellous bone. Finally, the vessels must have sufficient blood flow, regardless of diameter, to maintain bone viability

Vascularized Pedicle Bone Grafts from the Dorsal Distal Radius

The application of dorsal distal radius vascularized pedicle b

one grafts based on the anatomic studies of Sheetz et al. was recently reported (86,87,153).

In Kienböck's disease, revascularization with a vascular bundle or vascularized bone graft can be performed even in advanced (stage IIIb) cases, provided that an intact cartilage shell is present (i.e., without fracture or fragmentation) and no arthrosis is found. Revascularization is a logical alternative to load-altering procedures and is especially attractive in ulnar-neutral or -positive variance cases when radial shortening is contraindicated. Contraindications include stage IV disease and lunate fracture with extrusion or separation of fragments.

Two are superficial to the extensor retinaculum, supplying nutrient branches to the bone underlying bony tubercles between extensor tendon compartments. They are aptly named the 1,2 and 2,3 intercompartmental supraretinacular arteries (1,2 and 2,3 IC SRAs), the numbers denoting the extensor compartments

they pass between. The other two are deep vessels, located on the floor of extensor compartments, named the fourth and fifth extensor compartmental arteries (4th and 5th ECAs) for their specific anatomic location in the radial aspect of each compartment. The 1,2 IC SRA courses from the radial artery 5 cm proximal to the radiocarpal joint beneath the brachioradialis muscle to emerge on the dorsal surface of the extensor retinaculum. In the anatomic snuffbox, the 1,2 IC SRA anastomoses with the radial artery or the radiocarpal arch.

This vessel, based on its distal anastomotic connection to the radial artery, is the “ascending irrigating branch” described by Zaidemberg et al. (156). It is important to recognize that the vessel actually lies superficial to the extensor retinaculum rather than on the periosteum, as originally described. The 2,3 IC SRA originates from the anterior interosseous artery or the posterior division of the anterior interosseous artery.

It lies superficial to the extensor retinaculum directly over Lister's tubercle and anastomoses with the dorsal intercarpal arch, the dorsal radiocarpal arch, or the 4th ECA. Its nutrient artery branches penetrate deeply into cancellous bone. Like the 1,2 IC SRA, the 2,3 IC SRA can be easily harvested and used as a vascularized pedicle bone graft. The arc of rotation is greater and can reach the entire proximal row, making it useful for either Kienböck's disease or scaphoid nonunions.

Technique of Harvest: Fourth and Fifth Extensor Compartmental Graft

In the 4th and 5th ECA graft, retrograde flow from the 5th ECA is directed in an orthograde direction into the 4th ECA by ligation of the posterior division branch of the anterior interosseous artery proximal to the vessels' origin.

Unloading of the lunate is important during the revascularization process and may be accomplished by temporary unloading with an external fixation or temporary pinning of the midcarpal joint.

Results of Vascularized Bone Grafts for Kienböck's Disease Lunate revascularization techniques have demonstrat

ed promising clinical results for Kienböck's disease. Most series report excellent pain relief with improvement in range of motion and strength. Radiographic progression of lunate and carpal height collapse occurred in 0% to 15% of patients in recent studies (86,87 and 88), and radiographic and MRI evidence of revascularization is evident after surgery.

Lunate revascularization is especially attractive in ulnar-positive or -neutral Kienböck's disease, when joint leveling procedures are contraindicated. In these cases, the collapsed lunate may be gently expanded with the graft to improve the overall carpal height ratio and lunate index. Its use in ulnar-minus variant wrists is also reasonable, either alone or in combination with a leveling procedure.

Salvage Procedures

. Treatment in these instances requires the use of a salvage procedure rather than the unloading or revascularization options discussed above. Procedures useful in these circumstances include proximal row carpectomy, lunate excision with or without intercarpal fusion, lunate interposition arthroplasty with a variety of artificial or natural materials, and wrist arthrodesis.

Proximal Row Carpectomy

In symptomatic stage IIIb or IV Kienböck's disease, proximal row carpectomy may be considered, provided the capitate head and lunate fossa of the radius are in good condition. The need for concomitant radial styloidectomy is assessed intraoperatively after removal of the proximal row. Proximal row carpectomy was introduced in 1944 by Stamm, who used it in part for Kienböck's disease patients (168). Its use is still advocated today (169).

Lunate Excision

Simple excision of the lunate without replacement may achieve satisfactory pain relief at times (170). Resection arthroplasty is an alternative for patients

Either SC or STT arthrodesis will maintain carpal height and prevent or correct scaphoid rotary subluxation, which would be likely after lunate resection.

Lunate replacement

Lunate replacement has a long history, starting with vitallium prostheses, described by Lippman in 1949 (171), and acrylic materials (172). Silastic lunate arthroplasty was later popularized by Swanson, followed by titanium implants. Subsequent reports of particulate silicone causing foreign-body reactive arthritis and continued problems with carpal instability have led most surgeons to abandon this technique

total wrist arthrodesis

For patients with generalized carpal arthrosis (stage IV Kienböck's disease) or unsuccessful previous reconstructive surgeries, total wrist arthrodesis is the most reliable procedure for pain relief. Partial wrist denervation by transection of the articular branches of the posterior or anterior interosseous nerves (169) or complete wrist denervation (182) may be a useful adjunct to these procedures. In a recent report, either method provided substantial pain relief in Kienböck's patients (183). Total wrist arthroplasty is contraindicated in these generally young and active patients

Vascularised Bone Graft

Salvage procedures

Wrist arthrodesis

Proximal row carpectomy

Wrist arthroplasty - not

Wrist Fusion

What I do

treat conservatively after patient education

Stage 1 - 3 & ulna minus : Radial shortening

Stage 1 - 3 & ulna neutral : STT

Stage 4 : arthrodesis

Thank you