SEMINAR ONScaphoid and lunate fractures

Moderator :- Dr.O.B.PattanashettyPresentor :- Dr.Hari krishna Bachu

Scaphoid Fracture

•Introduction•Anatomy•Biomechanics•Mechanism of injury.•Classification•Clinical picture& Diagnosis•Management•Conclusion. 

Scaphoid Fractures• The scaphoid is the most frequently fractured

carpal bone, accounting for 71% of all carpal bone fractures.

• Scaphoid fractures been reported in individuals ranging from 10 to 70 years old, although it is most common in youngmen.

• About 5-12% of scaphoid fractures are associated with other fractures

• 70-80% occur at the waist or mid-portion• 10-20% proximal pole

Anatomy

Anatomy• The scaphoid lies at the radial border of the

proximal carpal row, but its elongated shape and position allow bridging between the 2 carpal rows because it acts as a stabilizing rod.

• The scaphoid has 5 articulating surfaces:– with the radius, lunate, capitate, trapezoid, and

trapezium.

• As a result, nearly the entire surface is covered by hyaline cartilage.

• It connected with rest of the carpal bones through various ligaments among those volar ligaments are more strong than dorsal group

• Distally articulates with trapezium in a gliding movement gives independent movement to thumb

• On the ulnar side articulates with capitate, proximally with Lunate in a rotatory movement

• Proximally the convex surface articulates with distal end of radius

Blood Supply

• Vessels may enter only at the sites of ligamentous attachment: – the flexor retinaculum at the tubercle, – the volar ligaments along the palmar surface, – and the dorsal radiocarpal and radial collateral

ligaments along the dorsal ridge.

Blood Supply The primary blood supply comes from the dorsal branch

of the radial artery, which divides into 2-4 branches before entering the waist of the scaphoid along the dorsal ridge.

The branches course volar and proximal within the bone, supplying 70-85% of the scaphoid.

The volar scaphoid branch also enters the bone as several perforators in the region of the tubercle; these supply the distal 20%-30% of the bone

Arterial supply of dorsum of wrist.

The dorsal arches are (1) the dorsal radiocarpal at theradiocarpal joint, supplying the lunate and triquetrum; (2)the dorsal intercarpal (the largest) between the proximaland distal carpal rows, supplying the distal carpal row and,through anastomoses with the radiocarpal arch, the lunateand triquetrum; and (3) the basal metacarpal arch at thebase of the metacarpals (the most variable) to supply the distal carpal row.

The palmar arches are

(1) the palmar radiocarpal at the level of the radiocarpal joint to the palmarsurfaces of the lunate and triquetrum(2) the intercarpalarch between the proximal and distal carpal rows, which is the most variable and does not contribute to nutrientvessels in the carpus(3) the deep palmar arch at the level of the metacarpal bases, which is consistent and communicateswith the dorsal basal metacarpal arch and thepalmar metacarpal arteries

Arterial supply of palmar aspectof wrist

Blood Supply• All studies consistently demonstrated poor supply

to the proximal pole• The proximal pole is an intra-articular structure

completely covered by hyaline cartilage with a single ligamentous attachment

–Deep radioscapholunate ligament• Is dependent on intraosseous blood supply

                                                       

Blood SupplyObletz and Halbstein in their study of vascular

foramina in dried scaphoids found 13% without vascular perforations and 20% with only a single small foramen proximal to the waist

Therefore postulated that atleast 30% of mid-third fracture would expect AVN of proximal pole…greater likelihood the more proximal the fracture

Mechanism of injury

1. Fall on outstretched hand force absorbed on the radial side of the

Hand2. Hyper extension of the wrist presses the scaphoid against

the dorsal rim of the radius3. The strong volar scapho lunate, lig holds the proximal half

scaphoid the distal half is carried up, results in transverse fracture that starts volarly and proresses dorsally.

4. Compression injury- un displaced Frature5. Hyperextension injury- displaced Fracture

Biomechanics

Scaphoid • flexes on

radialdeviation ,& palmar flexion of the wrist,

• extends on extension & on ulnar

deviation

Biomechanics

• The stable Fr maintains the normal orientation for proximal and distal rows

• Unstable Fr angulates dorsally and produces –Humpback deformity

• Results in DISI• Grip weakness, late OA

• When fractured,

proximal pole - extend with attached lunate

distal pole - remains flexed, creating hump-back deformity.

Diagnosis Suggested by:

– patient’s age, – mechanism of injury and – signs and symptoms

Imaging– Xray– CT Scan– MRI– Bone Scan

Radiography• The 4 essential views (ie, PA, lateral, supinated and

pronated obliques) identify majority of fractures. • The scaphoid view is a PA radiograph with the wrist

extended 30° and deviated ulnarly 20°. This view helps to stretch out the scaphoid and is also used for assessing the degree of scaphoid fracture angulation.

• A clenched-fist radiograph has also been useful for visualization of the scaphoid waist.

• Motion views of the wrist ( flexion-extension-radial & ulnar deviation ) may demonstrate fracture displacement

• If a diagnosis still can’t be confirmed on routine films, further oblique views can be taken • If Uncertainty still exists after all these maneuvers ,

the patient should be placed in a cast for 2 to 4 weeks and the clinical & radiographic evaluation repeated

CT Scan

• CT permits accurate anatomic assessment of the fracture.

• Bone contusions are not evaluated with CT, but true fractures can be excluded

MRI• T1-weighted images obtained in a single plane

(coronal) are typically sufficient to determine the presence of a scaphoid fracture.

• Gaebler prospectively performed MRI on 32 patients, at average of 2.8 days post injury– 100% sensitivity and specificity

• In recent study Dorsay has shown that immediate MRI provides cost benefit when compared to splintage and repeat xray

• False positives due MRI’s sensitivity to marrow oedema

Nuclear Imaging• Radionuclide bone scanning typically is performed 3-7

days after the initial injury if the radiographic findings are normal.

• Best at 48hours, premature imaging may be obscured by traumatic synovitis

• Bone scan findings are considered positive for a fracture when intense, focal tracer accumulation is identified.

• Negative bone scan results virtually exclude scaphoid fracture

• Teil-van studied cost effectiveness and concluded that initial xray followed by bone scan at 2 weeks if patient is still symptomatic is most effective management option

• more sensitive and less expensive than MRI

Classification

• Determining optimal treatment depends on accurate diagnosis and fracture classification

• Herbert devised an alpha-numeric system that combined fracture anatomy, stability and chronicity of injury.

Herbert classification

stability and delayed & nonunion of fractures.

Type A fractures- stable

Type A1- fracture of tubercle

Type A2 – incomplete fractures through waist

Type B –Acute and Unstable fractures

Type B1- oblique Distal third fractures

Type B2- displaced waist fracture

Type B3- Proximal third fractures

Type B4- Transscaphoid & Perilunate dislocations of carpus

Type B5-Comminuted

• Type C fractures – Delayed unions

• Type D fractures – established Nonunions• D1: fibrous nonunion• D2: pseudarthosis

Classification• Russe 1) Horizontal oblique - compressive forces across fracture

site.

2) Transverse –combination of compressive & shear forces.

3) Vertical oblique – 5% , shear forces across fracture site.

Russe

Prosser classification

Classification of Distal pole fractures

Type 1 – Tuberosity fracture.

Type 2 - Distal intra-articular fracture.

Type 3 – Osteochondral fracture.

Prosser Classification

Classification according to location

A: tubercle

B: distal pole

C: waist

D:proximal pole

Diagnosis

• Wrist pain

• Tenderness & fullness in anatomic snuffbox.

• Axial compression of thumb elicits pain

• Forced ulnar deviation of pronated wrist also elicits pain

Clinical presentationTime since injury• Acute fracture - less than 3 weeks old• Delayed union - 4 to 6 months old• Nonunion - more than 6 months old

Amount of fracture displacement ( stability ) :

• Un displaced ---- stable• Displaced ---- unstable

• The unstable fracture (displaced) is defined as :

- presence of a fracture gap > 1 mm on any radiographic projection - scapho lunate angle >60 - radio lunate angle > 15 or intrascaphoid angle > 20

• B/E or A/E Cast (Fore arm supinaton/Pronation)Long arm cast is recommended for non displaced proximal pole fr• Thumb or Three fingers To maintain the alignment of the Scaphoid in unstable Fr

• Duration of Treatment ‘’ longer the immobilization better is healing”

• Consider changing the cast every 10-14 days for the first 6 weeks so that it remains firm around forearm muscles and the wrist

• Time to healing by location : – Distal third fr heals in 6-8 weeks – Middle third fr 8-12 weeks – Proximal third fr 12-24 weeks

• A 95 % union rate can be expected with this management

• undisplaced, stable fractures if diagnosed and immobilized early (95 % with x-ray evidence of beginning consolidation at 6 weeks )

Stable Fractures- Cast Immobilization.• Initial delay in treatment does not preclude casting • If treatment is instituted within4weeks no effect on healing time or rate of union has been shown • Delay beyond 6 months invariably requires operative treatment • The difficulty lies in fractures between 6 weeks and 6 months. ---If no evidence of bony resorption exists, casting may result in union. ---- If bony resorption or displacement, greater than 1 mm exists, operative reduction and bone grafting will be needed

Stable Fractures- Surgical treatment

Indications.1. Professionally high demand pt 2. Pt who cannot tolerate prolonged immobilization

Treated byPercutaneous Screw fixation- volar /dorsal approach

Unstable Fractures conservative Treatment

1. Poor risk Pt2. Pt not willing for Surgical

Treatment3. Closed manipulation& cast

Immobilization-- 3 point fixation with dorsal pressure on capitate & lunate ,volar pressure over the distal end of scaphoid ( rotates the lunate,proximal fragment into flexion)- cast A/E ,slight dorsi flexion radial deviation, thumb/ 3 finger cast

Complications of Scaphoid Frctures

• Delayed union or Nonunion• Malunion (Humpback deformity)• SLAC wrist• Osteonecrosis

Treatment of middle third fractures

• They are the commonest (65%)• If fresh stable: short-arm thumb spica cast• If fresh undisplaced but potentially unstable

(e.g. vertical oblique) and stable factures older than 3 wks : long-arm thumb spica cast

• If fresh displaced : ORIF (k-wires or screws)

Proximal Pole Fractures• challenging• Often difficult to heal• Prolonged immobilization- snug , well molded long arm cast-

(sometimes exceeds 9 mos) has been necessary with conventional casting

• Early incorporation of PES has been recommended• Displaced Fractures:• Fragment small- K wire fixation• Fragment is 1/3 of Scaphoid Screw fixation – Dorsal app• Determination of bony union is not easy• Tomography or CT is needed• Multiple follow up films should be obtained for

several months after the assumed healing

Distal Pole Fractures

• These are often avulsion injuries of the tuberosity and can be expected to heal promptly with cast treatment

• Fresh and undisplaced should heal in 4-8 wks in a cast

• Displaced fr needs ORIF

Scaphoid Fracture-- Nonunion

• The incidence of scaphoid nonunion for undisplaced fr is 5-10%

• The incidence increases up to 90% in displaced proximal pole frs

• Risk factors :– Proximal pole fr– Displacement– Late diagnosis– Inadequate immobilization– Associated ligamentous injuries

Classification

• Slade and Geissler• 1-(1) early nonunion without substantial bone

resorption– Grade I: fibrous union, minimal sclerosis(<1mm)Late presentation(>4 weeks)– Grade II: fibrous union apparently united in xray, but

is symptomatic– Grade III: minimal resorption, minimal

sclerosis(<2mm)

• (2) chronic nonunion with substantial bone resorption– Grade IV: well perfused, substantial bone loss(2-

5mm)– Grade V: well perfused , substantial bone loss (5-

10)– Grade VI: pseudoarthrosis W/O AVN

Scaphoid Fracture- Nonunion• Failure to heal after 6 months establishes the Dx

of nonunion• Recent studies indicated that virtually that “all

unstable non unions lead to carpal collapse and post traumatic arthritis,,

• All scaphoid nonunions even if asymptomatics hould be treated aggresively.

• Thin cut CT scan show more details than conventional tomograms

• Sagittal views are helpful in determining the degree of carpal collapse and humpback deformity

Scaphoid Fractures Nonunion Treatment

• Procedures available- • 1.Bone grafting,.• 2.Electrical stimulation• 3. Proximal pole excision• 4. Salvage proceduresLook for the following……• Comminution of Fracture site/ gape with collapse.• Avascularity of proximal pole• Orientation of lunate , Scapho-lunate angle, Intra scaphoid angulationProcedures of choice ….OR+ bone grafting No collapse- Inlay grafting- RUSSECOLLAPSE - interposition grafting-FERNANDASEproximal pole avascularity- vascular pedicle grafting

1. pronator Quadratus based2.Supra retinacular artery based

Matti-Russe procedure

•longitudinalincision 3 to 4 cm long on the volar aspect of the wrist.

•Protect the palmar cutaneous branch of the median nerveand the terminal branches of the superficial radial nerve•From the iliac crest, obtain a piece of cancellous bone andshape it into a large lozenge-shaped peg to fit into thepreformed cavity and stabilize the two fragments stability can be improved with a•Kirschner wire inserted from distal to proximal across thefracture.

Flexor carpiradialis

Graft

Malpositioned Nonunion of Scaphoid Fractures (“Humpback”Deformity).

• The deformity includes extension of the proximal pole of the scaphoid, Resulting extension of the lunate, and a form of dorsal intercalatedinstability pattern seen on lateral plain radiographs.

• The cannulated Herbert-Whipple screw was found tobe effective fixation.

• Herbert screw ismost effectivein nonunions with evidence of osteonecrosis, nonunionsinvolving the proximal third, or nonunions having had previousfailed bone grafts

Fernandez procedure• angulated nonunions with a

dorsal humpback deformity • Interpositional grafting.• Trapezoidal iliac graft to

correct the angulation and carpal collapse pattern.

• Fixation is achieved with screws or k-wires

• volar approach is used, and care must be taken to preserve the vascularity of the fragments

Vascularized grafts

Vascularized bone grafts techniques•Kawai and yamamoto•Zadiemberg et al

Pronator quadratus

Ununited scaphoid #

Pronator quadratus pedicle bone graft forscaphoid nonunion.

Pedicled vascularized bone graftBone grafting based on supra retinacular branch of radial artery

Non-union… treatment

Electrical stimulation:• Noninvasive treatment for scaphoid nonunion. Although

controversial, there appears to be some benefit (shorter healing time)when electric stimulation is combined with bone grafting procedures

• Proximal pole excision: when a small proximal fragment is not amenable to bone grafting ,proximal pole excision and fascial hemiarthroplasty are recommended

Salvage proceduresRadial styloidectomyDistal scaphoid resectionProximal row carpectomyPartial arthrodesis

Non-union… treatmentSalvage procedures :

• Are indicated when nonunion has lead to carpal collapse and secondary degenerative changes

• Proximal row carpectomy, intercarpal arthrodesis, or radiocarpal arthrodesis is recommended in patients with chronic wrist pain and stiffness

• Radial styloidectomy and scaphoid interposition arthroplasty may be combined with other procedures or performed independently in the younger patient with less severe symptoms

• Silicone implants have been used in the past but are now avoided because of silicone synovitis

Malunion

• Malunion of the scaphoid may occur when a displaced or angulated fracture is allowed to heal without anatomic reduction

• In most of cases , there is a dorsal angulation resulting in a fixed humpback deformity

• DISI pattern occurs ,resulting in pain ,loss of motion, and decreased grip strength

• Treatment in a young patient includes osteotomy,volar wedge bone graft, and internal fixation

• Once degenerative arthritis has begun ,treatment is limited to a salvage procedure such as proximal row carpectomy, intercarpal arthrodesis,or complete wrist fusion

conclusionScaphoid treatment should be planned based on…1 stability of fracture-stable/ unstable2. Anatomical Location of fracture( p1/3, waist, Distal1/3)3.Comminution at fractures site, avascularity of proximal pole4.Delayed or early presentation5. Features of non union6.Evidence of DISI( dorsal tilting of lunate)In cast application stable Fracture- thumb spica, A/E cast for

unstable fractures ,Stable proximal pole fr, 3 finger/ fist cast- displaced fractures, fractures associated with carpal instability.

Percuataneous fixation to be used with caution after patient is well informed and surgeon had enough open reduction experience

Reduction always should be Anatomical