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Dorsal Approach (Thompson)


- See:
      - Plating Techniques
      - Radial Shaft Fractures: Discussion

- Discussion:
    - dorsolateral approach is best suited to frxs of proximal & middle thirds of radius as well as to address injury to proximal RU joint;
    - advantages:
            - much less soft tissue stripping is required with this approach (as compared to anterior approach), and patients can expect
                       much more rapid return of wrist and hand function;
            - plate on the dorsal aspect of the proximal radius is less likely to produce mechanical block to pronation than if applied to the
                       anterior surface;
    - disadvantages:
            - potential risk of injury to PIN with proximal fractures;
            - risk of tendonitis from fist and second wrist compartment tendons with distal fractures;

- Interneural Approach:
     - interval between ECRB (Radial nerve) and EDC (PIN) (or EPL distally);
            - which is the same interval used in the lateral approach to the elbow;
     - PIN must be identified & protected w/ this approach;
     - exposing proximal third of radius is difficult because deep branch of radial nerve traverses it w/ in supinator;

- Surgical Technique:
     - arm position:
            - pt is supine w/ shoulder abducted and the arm resting on hand table;
            - arm is placed on arm board, w/ flexed elbow, & mid pronation of forearm;
     - incision:
            - radial extensor group is palpated (mobile wad of Henry: ECRL, ECRB and brachioradialis);
            - incision is made on line extending from lateral epicondyle of humerus to radial styloid process, along dorsal border of mobile wad;
            - alternatively, make skin incision over the proximal and middle thirds of radius along line 1.5 cm anterior to the lateral
                    humeral epicondyle;
                    - when forearm is pronated, this line is virtually straight;
                    - expose lateral (radial) border of extensor digitorum communis in the distal part of the incision;
            - fascia between digital extensors and mobile wad is split;
                    - this interval is sometimes more apparent distally where outcropping muscles of the thumb cross over the radius;
     - surgical dissection:
            - reflect EDC ulnarly to expose supinator muscle (which covers the dorsal aspect of proximal radius);
            - develop an interval between supinator & ECRB;
            - fascia between the ECRB & EDC is incised;
            - in the distal 1/3, APL and EPB emerge obliquely;
            - w/ careful dissection, separate both muscles from shaft of the radius, just sufficiently for a plate to be slipped beneath;
            - proximally, identify radial nerve before it enters supinator and then emerges distally from the muscle;
                    - some surgeons prefer to identify the nerve distal to the supinator, where it lies in the 4th compartment;
            - subperiosteal dissection of the supinator:
                    - bring the forearm into full supination, to bring its insertion into view;
                    - free muscle from bone subperiosteally from its insertion and reflect it either proximally or distally w/ nerve;
            - APL is visible distally, retract it distally and ulnarly to expose part of posterior surface of radius;
            - continue dissection proximally between EDC & ECRB-ECRL to lateral humeral epicondyle

Vulnerability of the posterior interosseous nerve during proximal radius exposures.

Anatomical methods of approach in operations on the long bones of the extremities.   

Surgical exposure of the dorsal proximal third of the radius: how vulnerable is the posterior interosseous nerve?

The posterior interosseous nerve and the posterolateral approach to the proximal radius.