Orthopaedics: Wrist

Wrist

Colles' Fracture

Definition

·                 transverse distal radius fracture (about 2 an proximal to the radiocarpal Joint) with dorsal displacement ± ulnar styloid fracture

Epidemiology

·                 most common fracture in those >40 years, espedal1y in women and those with osteoporotic bone

Mechanism

·                 FOOSH

Clinical Features

·                 dinner fork'" deformity

·                 swelling, ecchymosis, tenderness

Investigations

·                 findings on x-ray (Figure 27)

Treatment

·                 goal is to restore radial height, radial inclination (22•), volar tilt (11 °) and articular congruity

·                 closed reduction (think. opposite of the deformity):

o       hematoma block (sterile prep and drape, local anesthetic injection directly into fracture site) or conscious sedation

o       closed reduction -traction with extension (exaggerate injury), then traction with ulnar deviation, pronation, flexion of distal fragment - not at wrist)

·                 dorsal slab/below elbow cast for 5-6 weeks

·                 x-ray ql week to ensure reduction is maintained

·                 obtain post-reduction films immediately; repeat reduction if necessary, consider external fixation or ORIF

Smith's Fracture

Definition

·                 volar displacement of the distal radius (i.e. reverse Colles' fracture)

Mechanism

·                 fall onto the back of the flexed hand

Treatment

·                 usually unstable and needs ORIF

·                 if patient is poor operative candidate, may attempt non-operative treatment

·                 closed reduction with hematoma block (reduction opposite of Colles')

·                 long-arm cast in supination x 6 weeks

Complications of Wrist Fractures

·                 most common complications are poor grip strength, stiffness, and radial shortening

·                 distal radius fractures in individuals <40 years of age are usually highly comminuted and are likely to require ORIF

·                 80% have normal function in 6-12 months

·                 early

o       difficult reduction ± loss of reduction

o       compartment syndrome

o       extensor pollicis longus (EPL) tendon rupture

o       acute carpal tunnel syndrome

o       finger swelling with venous or lymphatic block

·                 late

o       mal-union, radial shortening

o       painful wrist secondary to ulnar prominence

o       frozen shoulder ("shoulder-hand syndrome'')

o       post-traumatic arthritis

o       carpal tunnel syndrome

o       complex regional pain syndrome (reflex sympathetic dystrophy (RSD))

Scaphoid Fracture

Epidemiology

·                 common in young men; not common in children or in patients beyond middle age

Mechanism

·                 FOOSH resulting most commonly in a transverse fracture through the waist (middle) of the scaphoid

Clinical Features

·                 pain on wrist movement

·                 tenderness in scaphoid region (anatomical "snuff box")

·                 usually undisplaced

Investigations

·                 x-ray: AP, lateral, scaphoid views with wrist extension and ulnar deviation q2 weeks

·                 ±bone scan

·                 ±CT,MRI

·                 Note: a fracture may not be radiologically evident up to 2 weeks after acute injury, so if a patient complains of wrist pain and has anatomical snuffbox tenderness but a negative x-ray, treat as if positive for a scaphoid fracture and repeat x-ray 2 weeks later to rule out a fracture. If x-ray still negative order CT or MRI

Treatment

·                 non-displaced= long-arm thumb spica cast x 4 weeks then short arm cast until radiographic evidence of healing is seen (2-3 months)

·                 displaced = open (or percutaneous) screw fixation

Specific Complications (see General Fracture Complications)

·                 AVN of the proximal fragment (since the scaphoid has distal to proximal blood supply, the more proximal the fracture, the greater incidence of AVN)

·                 delayed union (recommend surgical fixation)

·                 non-union (must use bone graft and fixation to heal)

Prognosis

·                 fractures of the proximal third of the scaphoid have 70% rate ofnon-union or AVN

·                 waist fractures have healing rates of 80-90%

·                 distal third fractures have healing rates close to 100%