forearm trauma

Question 1

Radius and ulnar midshaft forearm fracture management?

Answer 1

Goal of surgery:
- restore bow of forearm
- restore length
- restore rotation

achieved by:
- anatomical reduction
- interfragmentary compression
- rigid fixation

Order of fixation:
- ulnar first to restore length - normally less comminuted

Position
- supine with arm board
- ulnar fixed with elbow resting of the table and the forearm held vertically
- radius fixed with arm abducted and forearm supinated

Ulnar fixation
- subcutaneous border of the ulnar
- options - lag screw and protection plate or pre-bent dynamic compression plate to stop contralateral gapping
- plate on dorsal side for midshaft
- 6 cortices either side of the fracture

Radius fixation
- Henry’s approach
- danger - lateral cutaneous branch of forearm
- fix butterfly fragment with lag screw first to one end - now 2 part fracture
- deliver bone ends, accentuate fracture, rotate to reduce - control with clamps
- LCP plate - prebent - fracture reduces into the axilla formed by the plate and other side of the fracture
- minimum of 6 cortices either side to control torsional forces

CHECK ROTATION

Question 2

Galeazzi fracture management?

Answer 2

Immediate management
- reduction and above elbow cast in supination

Definitive management

Goals
- restore length, rotation and bow of forearm

Radius fixation
- FCR approach +/- extended approach
- plate - LCP or volar locking plate depending on level of fracture

DRUJ
Causes of subluxation after radius fixation
1. malreduced radius
2. interposition of ECU most common

• if reduces on radius fixation and rotationally stable - above elbow cast in supination 2 weeks
• if reduces on radius fixation but unstable - K-wire to transfix and cast in position of maximum stability - 4 weeks
• If irreducible - open reduction of DRUJ and K-wire transfixation

note - sugar tong cast can allow elbow movement but maintain DRUJ reduction

DRUJ - open reduction
- approach dependent on direction of dislocation - commonly posterior
- dorsal approach - between 4th and 5th compartments
- remove interposing ECU tendon and reduce DRUJ
- repair capsule
- transfix in position of maximum stability

Question 3

Bado classification of monteggia fractures

Answer 3

• Type I - 80% - anterior dislocation of radial head diaphyseal ulnar fracture
• Type II - posterior dislocation of radial head and diaphyseal ulnar fracture
• Type III - lateral dislocation of radial head and metaphyseal ulnar fracture
• Type IV - anterior dislocation of radial head and proximal third radial/ulnar diaphyseal fractures

Question 4

management of a monteggia fracture?

Answer 4

Immediate management
- NV assessment
- soft tissue assessment
- reduce and above elbow cast

Definitive management
Goal
- restore length, rotation and bow of forearm
- reduce the radiocapitellar joint

Achieved by
- anatomical reduction
- interfragmentary compression
- rigid fixation

Position
- lateral
- arm in a padded gutter - forearm dependent

Approach
- skin incision - olecranon process - ulnar styloid process
- fat and fascia inline with skin incision
- internervous plane - ECU (PIN) and FCU (Ulnar nerve)

Fixation
- radial head reduction first - pronation, traction, varus and direct pressure on radial head
- LCP or LC-DCP plate - locking compression plate - transverse fractures
- 2x cortical screws for compression then remainder locking screws - no further cortical after locking as it becomes a fixed angle device - further cortical screws would lead to losening at the bone/ screw interface
- lag screw + LCP - oblique fracture
- 6 cortices (3 holes) prox and distal to fracture
- repair fascia

Blocks to radiocapitellar reduction:
- Ulnar malreduction
- soft tissue interposition - annular ligament, anconeus

If radial head fails to reduce:
- Kocher approach - ECU (PIN) and Anconeus (Radial nerve)
- remove interposing tissue (annular ligament)

Paediatric monteggia fractures:
- deformation of the ulnar - may need to perform an ulnar osteotomy to reduce the radiocapitellar joint

Risks
- PIN injury from radial head - spontaneously resolves at 2-3 months