Abstract
A previous incision, usually near the midline, is always present and should be used whenever possible. It is preferable to use the most recent and/or most lateral longitudinal old incision. In addition, the surgeon should follow general principles of surgical exposure; i.e., avoiding isolated strips of tissue and crossing transverse incisions at right angles. Whenever adherent skin or marginal skin is present, a sham incision, tissue expansion, and tissue transfer should be considered.
Protecting the patellar tendon from avulsion is essential during revision surgery. In routine revision cases, a 15.75 mm pin should be placed in the center of the tibial tubercle to avoid distal avulsion. To avoid interfering with the stem location of a revision component, the pin should be directed toward the lateral plateau. Whenever the patient has less than 90° of knee flexion, the extensor mechanism has lost its elasticity and must be relaxed either proximally, by dividing the quadriceps tendon, or distally, by performing a tibial tubercle osteotomy.
The classic rectus snip is performed at the musculotendinous junction of the rectus femoris. The rectus snip may improve knee flexion at the expense of a minor extension lag. If the extensor mechanism is relaxed distally, the tubercle osteotomy should be 4 to 6 cm in length, taking care to preserve the fascial attachments on the lateral side of the osteotomised segment. After surgery, the fragment is reattached with heavy gauge wire. A disadvantage is that the osteotomy is subcutaneous and postoperative wound drainage in this location can be problematic.
In some instances capsular scar is extensive. The scar must be excised and the medial and lateral gutters cleared to achieve knee flexion. In extreme cases, the knee may need to be destabilised in flexion to gain exposure. This is accomplished either with a peel of the capsule and ligaments from the medial side of the femur, or with an epicondylar osteotomy that detaches the collateral ligaments from the medial condyle. The osteotomised bone wafer is reattached with heavy sutures to the medial condyle prior to closure.
The abstracts were prepared by Mrs Dorothy L. Granchi, Course Coordinator. Correspondence should be addressed to her at PMB 295, 8000 Plaza Boulevard, Mentor, Ohio 44060, USA.
