Fr actures of The Distal R adius Dr. A saad Qaddor i
ANATOMY- The distal radius is biconcave,triangular, and covered withhyaline cartilage.- The articular surface has twofacets for articulation with thescaphoid, & lunate.- The medial surface forms asemicircular notch whicharticulates with the ulnar head.
The distal radius and ulna articulate atthe radioulnar joint. The triangularfibrocartilage (TFC )is a key stabilizerof the distal radioulnar joint.The pronator quadratus is associatedwith an underlying fat pad seen as aflat, lucent line on the lateral image.
Imaging1- Posteroanterior (PA)2- lateral3-oblique radiographs: (reveal intra-articularinvolvement)A- The semisupinated, demonstrates thedorsal facet of the lunate fossa.B- The partially pronated, allows visualizationof the radial styloid.
Assessment of Radiological parameters1-Radial height (PA view)Two Tangential Lines to the Styloid tip anddistal ulnar srurface normal is 11-13mm2-Ulnar variance (UV) measured on PAradiograph w/ wrist in neutral .This image demonstrates ulnar plusvariance.
Ulnar variance is described as being zero( neutral) , minus, or plus.Ulnar variance does not depend on the length of the ulnar styloidbut on the positioning of the forearm, & the radiographictechnique.
3-Radial inclination is measured onthe PA viewThe normal angle is 15-25º.
4-The volar tilt, or palmar inclination, ismeasured on the lateral view.Slope of the dorsal-to-palmar surface of theradius. The normal angle is 10-25º.On the lateral view, the deep fat pad of thepronator quadratus and the dorsal skinsubcutaneous fat line can be seen anteriorto the distal radius.
PATHOMECHANICSInjury depends on the position of the wrist, the magnitude and direction of force,and the physical properties of the bone.A fall on the outstretched hand with the wrist in 40° to 90° of dorsiflexion produces adistal radius fracture with dorsal displacement .The lunate can exert a compressive force on the distal radius, producing a so-called die-punch fracture .The ulnar styloid fracture component of the Colles fracture results from a forcetransmitted through an intact triangular fibrocartilage complex.
PATHOMECHANICSFractures of the distal radius with palmar displacement are attributedto more than one mechanism of injury.1- A fall on the back of the flexed hand .2- A fall on the outstretched extended hand. A fall with the forearm insupination followed by pronation around a fixed extended wrist maybe the more common mechanism of injury.
PATHOMECHANICSRadial styloid fractures result from an avulsion (tensile) force generatedthrough the palmar radiocarpal ligaments.Careful evaluation of other ligamentous injuries (e.g., perilunatedislocations )should be given to the patient with a radial styloid fracture.
CLASSIFICATIONSUNIVERSAL CLASSIFICATIONBased on extraarticular versus intraarticular fractures and stable versusunstable fractures.FERNANDEZ AND JUPITER CLASSIFICATION- most recent classification scheme- identify stable versus unstable patterns,- childrens equivalent injuries,- associated lesions,- provide general recommendations for treatment
FRYKMAN Classification of Distal Radius FractureType FractureI Extraarticular radial fractureII Extraarticular radial fracture with an ulna fractureIII Intraarticular fracture of the radiocarpal joint without an ulna fractureIV Intraarticular radial fracture with an ulna fractureV Fracture of the radioulnar jointVI Fracture into the radioulnar joint with an ulnar fractureVII Intraarticular fracture involving radiocarpal and radioulnar jointsVIII Intraarticular fracture involving radiocarpal and radioulnar joints with an ulnar fracture
Fracture Description1- Location : Extra or Intra articular2- Configuration : Simple : transverse or oblique/ Comminuted.3- Displacement : Radial inclination Radial length Volar tilt intra-articular incongruity4- Ulna & DRUJ
Indication of Instability1- > 10 degrees loss of angulation2- > 5 mm of radial shortening3- > 2mm of articular incongruity4- comminution of cortex across the midaxial line on lateral x-ray5- comminution of dorsal and palmar cotices6- Irreducible fracture7-Loss of reduction at follow up.
Complications of Distal Radial Fractures1-Disruption of the triangular fibrocartilage (TFC) complex.2-Scapholunate and lunotriquetral interosseous ligament injuries.3- Ulnar nerve injury4-Carpal tunnel syndrome5-Posttraumatic radiocarpal osteoarthritis6-Heterotopic ossification7-Reflex sympathetic dystrophy (RSD)8-Tendon rupture (extensor pollicis longus)
EpidemiologyRaceno racial preferences have been reported.SexOlder postmenopausal women, with a female-to-male ratio of 4:1. However,in adolescent boys and girls, the ratio is 3:1,AgeA bimodal age distributionpeaks occur at ages 5-14 years and at ages 60-69 years.
Treatment Options1- Closed ReductionThe initial treatment for most radiusfractures is closed reduction andplaster immobilization.The cast is usually maintained forabout 6 weeks
Non-acceptable reduction:• Radial shortening > 5 mm• Radial inclination < 10°• Tilt on lateral projection > 10°dorsal tilt and > 20° volar tilt• Intra-articular step-off 2 mm ormore• Articular incongruity 2 mm ormore of the sigmoid notch (articularsurface of distal radius in DRUJ).
2- Surgical treatment- Failure to obtain or maintain closedreduction / or instable fracture pattern- 40% of distal radial fractures areconsidered to be unstable and requiresurgical fixation.- Surgical fixation allows almostimmediate mobility.- Ultimately less stiffness and greaterfunction is possible.
Types of fractures 1- Colles’ fracture : Low energy osteoporotic fracture 2- Smith’s fracture (Reversed Colles’): similar to Colles’ but displaced anteriorly rather than posteriorly. 3- Distal forearm fractures in children 4- Radial Styloid fracture : 5- Barton fracture : fracture subluxation of the wrist . 6- Comminuted intra- articular fractures in young adults.
Colles fractureA Colles fracture is a fracture of thedistal metaphysis of the radius withdorsal angulation and displacementleading to a silver fork deformityColles fractures are seen morefrequently with advancing age and inwomen with osteoporosis.
Lines of Closed treatment :Mold the plaster splintsFrequent follow up with imagingImmobilization of the wrist for a total of 6 weeks.Removable palmar splint for an additional few weeks.
Smiths fracture-Occur in younger patients- Result of high energy trauma- Volar comminution and intraarticularextension are more common.
Bartons fractureVolar-type Bartons is a fracture-dislocation of the volar rim of the radius.Dorsal-type Bartons is a fracture-dislocation of the dorsal rim of the radius.Shear type fractures of the distal articularsurface of the radiusHave a great tendency for redislocationand malunion.Usually require operative treatment.
Die-punch fracture- A depression fracture of the lunatefossa of the distal radius.- Result of a transverse load through thelunate.The radiographic findings can be verysubtle..
Chauffeurs fracture (Hutchinsons)- An isolated fracture of the radialstyloid process- Displacement of the fragment isuncommon.- There can be associated injury tothe scapholunate ligament.- Usually require surgicaltreatment .
Ulnar styloid process fracture- Usually associated with radialfractures and rarely isolated.- An isolated fracture of the tip isclinically insignificant.- Displaced fractures of the base areusually associated with TFC tears andcan be associated with instability ofthe distal radioulnar joint (DRUJ).
Fractures in Children1- Torus (buckle) fracture- Are extremely common injuries inchildren.- The word torus Tori meaningswelling or protuberance.- Tend to heal much more quicklythan the similar greenstick fractures.- Treatment : Short arm cast 3/52
Fractures in Children2- Green stick fracture- Only one part of the bone is brokenand the other side is bent.- Tension side with plastic deformation- reduce if angulation >10 degrees- Can take a long time to heal becausethey tend to occur in the middle, moreslowly growing parts of bone.
Fractures in Children3- Epiphyseal fracture-Usually Salter Harris type IIepiphysiolysis fractures- Restoring of the anatomicalsituation is necessary to preventgrowth disturbances.- Redislocation is common afterclosed reduction.- In many cases they needpercutaneous pinning.