Scaphoid Approaches

• By- Dr Piyush Rajesh PG 2nd Yr M.S. Orthopaedics I.M.C.H.R.C. , Indore

Scaphoid Fractures• The scaphoid is the most frequently fractured

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

• Scaphoid fractures often occur in young and middle-aged adults, typically those aged 15-60 years.

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

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

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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.

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 SupplyClassically described as 3 principal arterial

groups, but in more recent investigations by Gelberman and Menon described 2:– Entering dorsally– Volar side limited to tubercle

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

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

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’s ClassificationType A (stable acute fractures)– A1: fracture of tubercle– A2: incomplete fracture

Type B (unstable acute fractures)– B1: distal oblique– B2: complete fracture through waist– B3: proximal pole fracture– B4: trans-scaphoid perilunate fracture dislocation

of carpus

Herbert’s ClassificationType C (delayed union)

Type D (established non-union)– D1: fibrous union– D2: pseudarthrosis

Russe ClassificationRusse classified scaphoid fractures into 3 type

according to the relationship of the fracture line to the long axis of the scaphoid– Horizontal– Oblique– Vertical (unstable)

Classification according to location A: tubercle

B: distal pole

C: waist

D:proximal pole

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• Indications of Surgery in Scaphoid fractures

Displaced acute fracture Delayed union or nonunion when bone grafting is

insufficient to provide adequate internal fixation S.Fx associated with a perilunate fx or dislocation Ligamentous injury Non displaced fx of proximal pole Non displaced fx if the pt will not tolerate

prolonged cast immobilization (e.g. professional athletes and manual laborers )

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• ORIF of scaphoid fractures can be done by many ways :

K-wires ( easy insertion ) Herbert screws ( headless,

multipitched,difficult insertion ) AO screws Herbert-whipple screw Ender’s plate Staples

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• The surgical approaches :– Volar approach -- is most of the time the

preferred approach to limit the injury to the blood supply of the scaphoid

– Dorsal approach – will be used to address the fractures of the proximal approach

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Volar approach: between FCR and the radial artery

Complication$$• Malunion – Malunion may lead to limited motion about the wrist,

decreased grip strength, and pain. – The most frequent pattern of malunion is persistent

angular deformity, or the humpback deformity.– Malunion usually can be treated with osteotomy and bone

grafting to correct angular deformity and length. • Literature confusing with no comparative studies to

document improvement in hand function

Complication$$• Delayed union and non-union – Delayed union is incomplete union after 4 months of cast

immobilization. – Non-union is an unhealed fracture with smooth

fibrocartilage covering the fracture site. – About 10-15% of all scaphoid fractures do not unite. – Some degree of delayed union or non-union occurs in

nearly all proximal pole fractures and in 30% of scaphoid waist fractures

Complication$$ Delayed union is anticipated if fracture treatment is delayed

for several weeks. The risk of non-union increases after a delay of 4 weeks. These delays may be related to the patient's failure to seek

treatment for a presumed sprain, but they more frequently are related to improper or incomplete immobilization or a failure to diagnose and treat the acute fracture

Delayed union treatment If the delayed union is stable and less than 6 months old relative

to the time of injury, prolonged cast immobilization with or without electrical stimulation may be used.

Treatment of choice for a symptomatic non-union is placement of a bone graft and fixation. – Russe corticocancellous iliac graft– Fisk-Fernandez volar wedge graft– Pronator pedicle graft

• Braun ‘83 reported 100% union in 8 pts• Kawai, Kuhlmann, Papp reported 100% 37 pts

– Pechlaner reporrted 25 free vascularised iliac grafts with 100% Success rates for the treatment of non-union are as high as 82%.

AVN• Osteonecrosis occurs in 15-30% of all scaphoid fractures, and

most of these involve the proximal pole. • Its incidence increases as the fracture line becomes more

proximal; this decreases the probability that the blood supply to the proximal pole is preserved

Salvage proceduresRadial styloidectomyDistal scaphoid resectionProximal row carpectomyPartial arthrodesis