ORIF of Distal Radius Fractures - Wheeless' Textbook of Orthopaedics

- Discussion:
    - volar surface of distal part of radiusis slightly flattened, except for its distal margin, which slopes volarly to
             form a prominent ridge from which volar radiocarpal ligaments originate.
             - short radiolunate ligament originates off of volar marginof lunate facet and attaches to volar surface
                      of thelunate and helps maintaining stability of the radiolunate articulation;
    - ulnar volar margin of the lunatefacet slopes volarly as viewed from proximal to distal and maynot be effectively
             supported by standard implants;
             - volar rim of the distal part of the radius is not straight butslopes volarly from radial to ulnar;             - ulnar aspect of the volar rimof the radius is convex distally, forming a palmar prominenceof the lunate facet;
    - volarlunate facet extends more distally than is expected,which makes it more difficult to achieve adequate supportwith volar plate fixation;
    - fractures of lunate fossa:
             - volar shearing fracture with comminution creates a functionalradiolunate ligament avulsion, which can lead to instability;
             - volar aspectof the lunate fossa bears more load than the scaphoid fossa;
             - fracturesinvolving the volar lunate facet articular fragment can therefore be difficult to treat;
    - references:
              - Loss of Fixation of the Volar Lunate Facet Fragment in Fractures of the Distal Part of the Radius
              - The volar extension of the lunate facet of the distal radius: a quantitative anatomic study.

- Indications: Limited ORIF:
        - w/ limited ORIF, the distal radial metaphysis is exposed but the joint capsule remains unopened;
        - intra-articular frxs w/ > 2 millimeters of displacement;
        - restoration of articular anatomy is most critical factor in obtaining a good functional result;
        - risk factors for inadequate reduction include:
      - dorsal comminution;
      - interposition of volar soft tissues;
     - tendency for dorsal displacement & dorsal angulation;

- Open Reduction and Internal Fixation
- indicated when exposure of both the metaphysis and the joint is required;
- preoperative planning:
          - exam:
- if there is significant swelling the case may have to be delayed;
- patients should be examined for carpal tunnel symptoms before and after reduction;
- carpal tunnel symptoms that do not resolve following reduction will require carpal tunnel release;
          - radiographs distal radius frx:
- w/ volar Barton's frx, note whether there is more ulnar or radial sided comminution (since this can affect choice of surgical approach);
                - w/ multiple small articular fragments use of a plate may not be possible (then consider K wires & external fixation);
          - plate position:
- plate & screws can be applied volarly when major frx fragment is displaced volarly and dorsally to act as butress when major displacement is dorsal;
          - references:
                - Functional outcome of unstable distal radius fractures: ORIF with a volar fixed-angle tine plate versus external fixation.
                - Comparison of External and Percutaneous Pin Fixation with Plate Fixation for Intra-articular Distal Radial Fractures

- Surgical Approach:
    - dorsal approach and fixation:
    - anterior approach and fixation: (volar Barton's frx)
          - ref: Volar approach to distal radius fractures.
    - internal fixation: (implants for distal radius fractures):
- external fixator:
- before incision is made, distraction & temporary external fixator will facilitate reduction of small articular fragments;
          - plating techniques: (Synthes Distal Radius Plates)
- distal end of plate should be placed far enough proximally to avoid insertion of screws into articular surface;
- consider insertion of ulnar screws first to ensure that there is no joint tresspass (radial screws obstruct view of ulnar screws);
- bend plate to comform to the normal configuration of the radius;
- screws placed in diaphyseal bone will act as a butress for distal fragment;
- screws placed in distal metaphyseal fragments act more as internal sutures than rigid fixation, & these fragments may require additional K wires;
                 - ref: Fluoroscopic Evaluation of Intra-Articular Screw Placement During Locked Volar Plating of the Distal Radius: A Cadaveric Study
                 - hazards:
- tendon injuries: frequent reports of extensor tendonitis or rupture from dorsally applied hardware;
                              - Flexor Tendon Injuries Following Locked Volar Plating of Distal Radius Fractures
                              - Perforation of the third extensor compartment by the drill bit during palmar plating of the distal radius.
                              - Radiographic evaluation of dorsal screw penetration after volar fixed-angle plating of the distal radius: a cadaveric study.

- Complications of ORIF:

- References

Surgical treatment of fractures of the distal radius with plates: a comparison of palmar and dorsal plate position
Combined Dorsal and Volar Plate Fixation of Complex Fractures of the Distal Part of the Radius.
Loss of Fixation of the Volar Lunate Facet Fragment in Fractures of the Distal Part of the Radius.
Complications following internal fixation of unstable distal radius fracture with a palmar locking-plate.
A comparative study of clinical and radiologic outcomes of unstable colles type distal radius frx in patients older than 70 years: nonop treatment vs volar locking plating.
Functional outcome of unstable distal radius fractures: ORIF with a volar fixed-angle tine plate versus external fixation.
Volar fixation of dorsally displaced distal radius fractures using the 2.4-mm locking compression plates.
Functional outcome and complications after volar plating for dorsally displaced, unstable fractures of the distal radius.
Operative management of distal radial fractures with 2.4-millimeter locking plates. A multicenter prospective case series.
Prospective study of distal radius fractures treated with a volar locking plate system