- Discussion:
- lateral release detaches patella from lateral soft tissue structures, including lateral retinaculum, fibers from tensa fascia lata muscle, &
joint capsule;
- a tourniquet should not be used during this procedure since it has been shown to increase the occurance of postoperative hemarthrosis;
- prior to performing the release, a complete arthroscopic exam is performed, which includes the knee flexion angle at patellar
engagement and the knee flexion angle at patellar centralization;
- normally, patellar centralization should take place between 30-45 deg;
- part of the surgical statedgy is to avoid the superior geniculate artery;
- a needle can be placed adjacent to the superior pole of the patella (1 cm proximal and lateral to the superior edge of the patella) which
serves as a intra-articular marker;
- the arthroscope is switched from the anterolateral portal to the anteromedial portal;
- scissor release:
- metzenbaum scissors are inserted into the anterolateral portal and are used to bluntly spread over the retinaculum;
- the tips of the scissors are then placed across the retinaculum and are pushed superiorly in order to effect the release;
- care is taken to keep the curved tips of siccors directed posteriorly and 1 cm from the patellar edge;
- the release should be visualized thru the anteromedial portal;
- cautery release:
- turn the cautery on the lowest setting that allows tissue cutting (avoids iatrogenic damage);
- perform the retinacular release in layers starting from the superolaterally placed needle, and moving distally to the anterolateral portal;
- removing the fascia in layers allows a better opportunity to control bleeding;
- the release procedes until the subcutaneous tissue is visualized;
- care should be taken to avoid cutting the muscular fibers of the vastus lateralis;
- judge the adequacy of release:
- the patella should allow 45 deg of eversion following the release and/or should allow medial translation of 25% of the patellar width;
- document the change in knee flexion angles for patellar engagement and centrallization;
- following the release, hemstasis is achieved w/ cautery (note that bleeding often does not become manifest until several minutes following
the release, esp if a tourniquet is used)
- references:
- Arthroscopic determination of patellofemoral malalignment.
- The percutaneous lateral retinacular release.
- Arthroscopic lateral retinacular release and the lateral patellar compression syndrome.
Anatomy of the junction of the vastus lateralis tendon and the patellae.