Ortho-Preferred

Superomedial Portal



- Discusison:
    - traditionally used for the inflow cannula;
    - note that with modern pump equipment, the inflow canula is generally no necessary;

- technique:
    - place this cannula under direct visualization so that the cannula will not be placed under a plicae or into a thick wad of synovium;
            - note that repeated attempts to enter the joint will create additional openings into the joint which may allow extravasation of fluid;
    - skin and capsular incision should be as small as possible so that fluid does not extravasate into the subQ tissues or out of the skin;
    - traditionally this portal is placed several cm above the patella in line with the medial edge of the patella;
           - deep palpation will reveal a nice soft spot and will ensure that the incision is medial to the quadriceps tendon;
           - make the incision thru skin only skin the vastus medialis will readily separate as the blunt trocar is passed into the suprapatellar pouch;
                  - further, deep insertion of the knife often stirs up unnecessary bleeding, and creates a passage into the knee joint which may not always be followed by the trocar;
           - insert trochar beneath the vastus medialis and aim it distally and laterally to a point just superior to and lateral to the femoral trochlea;
                  - a gentle twisting motion facilitates entry of the trocar into the pouch;
                  - diffulty w/ insertion may indicate that the trocar has not been inserted deep enough (below the vastus);
           - disadvantage: patients will often have postoperative tenderness over the portal site;
    - alternative site is located just below the vastus medialis obliqus with the knee flexed 90 deg;
           - this ends up being just superior to the intersection of the superior and medial borders of the patella;
           - this location allows the cannula to be placed either in the medial gutter or in the trochlea (which ever allows the best inflow);
           - this portal site is associated w/ minimal postoperative tenderness and allows accelerated rehabilitation because the vastus medialis has been violated;      
    - maximizing inflow:
           - once this portal has been established, determine whether hypertrophic synovium or the fat pad may interfere with inflow down into the medial and/or lateral compartments (as well as the notch);
                  - if this is the case, then shave away the obstructing soft tissue until visualization of the medial and lateral compartments is not difficult



Technical note: Proximal superomedial portal in arthroscopy of the knee.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, September 13, 2012 3:38 pm