Distal Radius Fractures



Distal Radius Fractures


Kathryn Ashley Bentley

Nileshkumar M. Chaudhari



INTRODUCTION



  • Definition



    • Fracture of the distal end of the radius that originates in the metaphyseal region and often extends into the radiocarpal and distal radioulnar joints (DRUJs)


  • Epidemiology



    • Most common fracture seen in the emergency department


    • 3% of all upper extremity injuries


    • Incidence of 640 000 annually in the United States1


    • Bimodal distribution



      • 5- to 24-year-old high-energy predominantly male


      • Elderly low-energy predominantly female2



        • Associated with osteoporosis


        • At 7 years after fracture of the distal radius in the elderly, survival rates were lower than those individuals of the same age and gender in standard population.2


  • Anatomy



    • Distal radius is the articular surface on which the carpus rests.


    • Metaphysis of the distal radius is primarily cancellous bone.


    • Three articulations



      • Radioscaphoid articulation


      • Radiolunate articulation


      • Sigmoid notch (DRUJ)


    • 80% of axial load is supported by the distal radius and 20% by the ulna and triangular fibrocartilage complex (TFCC).3


  • Mechanism of injury



    • Younger individuals—falls from height, motor vehicle collisions, injury sustained during athletic participation



    • Older individuals—lower energy mechanisms such as falls from standing height


    • Pathomechanics



      • Dorsal displacement



        • Fall on an outstretched hand with the wrist in 40° to 90° of dorsiflexion results in a distal radius fracture with dorsal displacement.4


        • Volar side of radius initially fails in tension and then the fracture propagates dorsally where bending moment forces cause compression stresses that result in dorsal comminution.


      • Volar displacement



        • Fall on the back of the flexed hand or fall on a forearm in supination followed by pronation around a fixed extended wrist5


      • Shearing forces influence injury patterns as well as often resulting in articular surface involvement.3



        • Lunate can exert compressive forces on the distal radius, producing a die-punch fracture.4


  • Associated injuries



    • Up to 68% of distal radius fractures are associated with soft tissue injuries.



      • TFCC injury


      • Scapholunate ligament injury


      • Lunotriquetral ligament injury6,7


    • Median nerve injury8


EVALUATION



  • History



    • Mechanism


    • Identification of associated traumatic injuries


    • Physiologic patient age and comorbidities


    • Lifestyle


    • Occupation


    • Hand dominance


  • Physical examination



    • Skin should be inspected for any compromise.



    • Swelling, ecchymosis, and tenderness to palpation about the wrist


    • Deformity of the wrist is common.


    • Careful neurovascular examination should be performed with particular attention to median nerve function.


    • Ipsilateral elbow and shoulder should also be examined for associated injuries.


  • Imaging



    • Radiographs of the elbow, forearm, wrist, and hand


    • Posteroanterior and lateral views of the wrist should be obtained.



    • CT scanning may help with fracture characterization.3


  • Classification



    • Descriptive



      • Open versus closed, displacement, angulation, comminution, loss of radial length


    • Eponyms



      • Colles fracture (Figure 26.4A and B)



        • Extra-articular/intra-articular distal radius fractures demonstrating various combinations of dorsal angulation, dorsal displacement, radial shift, and radial shortening with associated ulnar styloid fracture


        • “Dinner fork” deformity clinically


        • More than 90% of distal radius fractures


        • Mechanism of injury is fall onto hyperextended, radially deviated wrist with the forearm in pronation.


      • Smith fracture



        • Reverse Colles fracture


        • Fracture with volar angulation of the distal radius with volar displacement of the hand and distal radius


        • Very unstable fracture pattern


        • Mechanism of injury is a fall onto a flexed wrist with the forearm fixed in supination.


      • Barton fracture



        • Fracture—dislocation/subluxation of the wrist in which the dorsal or volar rim of the distal radius is displaced with the hand and carpus.




        • Very unstable fracture pattern


        • Mechanism of injury is a fall onto an extended wrist with the forearm fixed in pronation.


      • Chauffeur fracture (radial styloid fracture)



        • Avulsion fracture with extrinsic ligaments remaining attached to the styloid fragment


        • May involve entire styloid or only the dorsal/volar portion


        • Often associated with carpal ligament injury patterns (ie, perilunate dislocations)


        • Mechanism of injury is compression of the scaphoid into the styloid with the wrist in extension and ulnar deviation (ie, chauffeur being struck by the backfire recoil of a starter crank on an early automobile engine)3,9



    • Frykman classification of Colles fractures



      • Type I: extra-articular without distal ulna fracture


      • Type II: extra-articular with distal ulna fracture


      • Type III: intra-articular involving radiocarpal joint without distal ulna fracture


      • Type IV: intra-articular involving radiocarpal joint with distal ulna fracture


      • Type V: intra-articular involving DRUJ without distal ulna fracture


      • Type VI: intra-articular involving DRUJ with distal ulna fracture


      • Type VII: intra-articular involving radiocarpal and DRUJ without distal ulna fracture


      • Type VIII: intra-articular involving radiocarpal and DRUJ with distal ulna fracture



    • Melone classification of intra-articular fractures (lunate impaction injury)

May 7, 2019 | Posted by in ORTHOPEDIC | Comments Off on Distal Radius Fractures
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