Orthopaedics: Forearm

Forearm

Radius and Ulna Fracture

Mechanism

·                 commonly a FOOSH or direct blow

Investigations

·                 x-ray: 1) AP and lateral of forearm; 2) AP, lateral, oblique of elbow and wrist

·                 CT if fracture is close to joint

Treatment

·                 goal is anatomic reduction since imperfect alignment significantly limits forearm pronation and supination

·                 ORIF with compresslon plates and screws

Monteggia Fracture

Definition

·                 fracture of the proximal ulna with radial head dislocation

Mechanism

·                 direct blow on the posterior aspect of the forearm.

·                 hyperpronation

·                 fall on the hyperextended elbow

Clinical Features

·                 decreased rotation of forearm ± palpation lump at the radial head

·                 ulna angled apex anterior and radial head dislocated anteriorly (rarely the reverie deformity occurs)

Treatment

·                 ORIF of ulna with indirect radius reduction in 90%

·                 splint and early post-op ROM if elbow completely stable; otherwise immobilization in plaster with elbow flexed for 6 weeks

Specific Complications (see General Fracture Complications)

·                 compartment syndrome

·                 radial/posterior interosseous nerve (PIN) injury

·                 decreased ROM

Nightstick Fracture

Definition

·                 isolated fracture of ulna

Mechanism

·                 direct blow to forearm (holding arm up to protect face)

Treatment

·                 non-displaced: below elbow cast (10 days) followed by forearm brace (-8 weeks)

·                 displaced: ORIF if >5096 shaft displacement or >10° angulation

Galeazzi Fracture

Definition

·                 fracture of the distal radial shaft with disruption of the distal radioulnar joint (DRUJ)

·                 most commonly in the distall 1/3 of radius near junction of metaphysis/diaphysis

Mechanism

·                 usual cause is fall on the hand (mechanical axial loading ofpronated forearm)

lnvestigations

·                 x-rays

o       shortening of distal radius >5 mm relative to the distal ulna

o       widening of the DRUJ space on AP

o       dislocation of radius with respect to ulna on true lateral

Treatment

·                 ORIF of radius

·                 if DRUJ is stable, splint with early ROM

·                 if DRUJ ill unstable, DRUJ pinning and long arm cast in supination x 6 weeks