A paramedial skin incision is made from just above the medial pole of the patella to a point 3 cm distal to the joint line just medial to the tibial tubercle – two thirds above the joint line to one third below (Fig. 7.5). Surgeons who are starting the procedure should make a longer incision starting level with the upper pole of the patella. The medial margin of the patella is identified. The retinacular incision is made along the medial side of the patella and patella tendon. The anterior tibia is exposed. At its upper end, the retinacular incision is extended proximally for 2 to 3 cm into the vastus medialis.
Figure 7.5 The incision.
Part of the retropatellar fat pad is excised and the anterior portion of the medial meniscus removed. Self-retaining retractors are inserted into the synovial cavity.
The ACL, lateral side and PFJ can now be inspected. If the ACL appears damaged, check its integrity by pulling on the ligament with a tendon hook. (Absence of a functioning ACL is a contraindication and the operation should be abandoned in favour of a total knee replacement.) A full thickness ulcer on the medial side of the lateral condyle and exposed bone in the PFJ can be ignored (see Chapter 5).