April 11, 2024

Scaphoid has a peculiar blood supply which makes its fracture much more clinically significant. Management of this fracture is challenging and depends upon the status of circulation.

Scaphoid blood supply
Blood supply of scaphoid

Anatomy

  • Cashew shaped structure
  • >80 % (except tubercle): Covered by articular cartilage
Anatomy of scaphoid

Scaphoid fracture

It comprises 68% of carpal bone fracture

Fall on outstretched hand and radial deviating is the mechanism of this injury

When fractured

The proximal pole will extend with an attached lunate ( Intercalated segment)

The distal pole will remain flexed, creating humpback deformity

Classifications

Rosse classification

  1. Horizontal oblique due to compression forces
  2. Transverse due to compressive and shear force
  3. Oblique due to shear force
Rosse classification of scaphoid fracture
Rosse classification

Anatomical

  1. Tuberosity
  2. Waist
  3. Proximal pole fracture

Herbert Classification

Herbert classification of scaphoid fractures
Herbert classification

Stability and delayed union of fractures

Type A (Stable)

Type A1: Tuberosity

Type A2: Waist

Type B (Unstable)

Type B1: Oblique distal 1/3rd

Type B2: Displaced waist

Type B3: Proximal 1/3rd fractures

Type B4: Fracture-dislocation

Type B5: Comminuted Fractures

Type C (Chronic)

Delayed union (After 6 weeks)

Type D (Established nonunion)

Type D1: Fibrous nonunion

Type D2: Sclerotic nonunion

Prosser classification

Distal pole fractures

Type 1: Tuberosity fracture

Type 2: Distal Intraarticular fracture

Type 3: Osteochondral fracture

Management of Scaphoid Fractures

Treatment options recommended for scaphoid fractures are:

Cast Immobilization

Undisplaced Stable fracture

A1: 4 weeks

A2: 8-12 weeks until radiographic nonunion

Should be reviewed 6 weeks after cast removal for the clinical and radiological outcome

Then, reviewed every 3 months until the outcome is clear

Should be seen for a final check-up after 1 year

Surgical Indication

Indications for surgical management is

  • Displaced fracture
  • Proximal pole fractures regardless of displacement
  • Associated peri lunate injuries
  • Open fractures
  • Polytrauma patient

A. Percutaneous Fixation

  • Along the central axis of the scaphoid use cannulated screw system (aim to keep the screw must centrally)

A1. Volar percutaneous approach

  • The distal scaphoid entry point
  • Use the 16-gauge needle to find the entry point

A2. Dorsal percutaneous approach

  • The proximal pole entry point

B. Arthroscopic

  • Herbert screw
  • Herbert-Whipple screw
  • Acutrak screw

C. Open: Palmar/ dorsal approach

Criteria for Unstable Fracture are

  1. >1mm displacement
  2. > 10 degrees angular displacement
  3. Fracture communition
  4. Radiolunate angle > 15 degrees
  5. Scapholunate angle >60 degrees
  6. Intrascaphoid angle >35 degrees

Non-Union Scaphoid Fracture Management

Principle of treatment

Proximal 1/3rd is more likely to go in nonunion due to its peculiar blood supply

If circulation is satisfactory which is determined by pre-operative MRI gadolinium scan/ intraoperative bone bleed then go for a non-vascularized bone graft with RIGID fixation

But when circulation is poor vascularized bone graft is necessary

Small, avascular, non-uniting fragment, excision should be done

Electrical / US stimulation also helps in non union of scaphoid fracture

Scaphoid Nonunion Advanced Collapse (SNAC)

In the long term, untreated scaphoid fracture nonunion will eventually go to SNAC

Stages of SNAC

Stage I: Arthritis of Radial Styloid

Stage II: Arthritis of Scaphoid fossa

Stage III: Arthritis of capitolunate

Stage IV: Diffuse arthritis of carpus

Preiser’s disease: Osteonecrosis of Scaphoid

Treatment options for neglected fracture with arthritis

Options:

  1. Radial Styloidectomy
  2. Excision of proximal fragment / distal fragment or entire scaphoid
  3. Proximal row carpectomy
  4. Traditional bone graft
  5. Partial / Total arthrodesis of wrist