The setup
The set up is the same as for medial OUKA using the leg holder (see Fig. 7.4). The hip is abducted. The thigh is supported so the hip is flexed 30 – 40°. This should allow the knee to hang flexed at 100 – 110°. The thigh support should avoid the popliteal fossa. It should be possible to flex the knee to about 135°.
Figure 12.10 Skin incision for lateral parapatellar approach (left knee).
Incision
The incision is made over the junction of the central and lateral third of the patella and begins at the level of the superior pole of the patella and extends down to, and just lateral to, the tibial tubercle (Figs. 12.10 & 12.11). The retinacular incision is made around the lateral side of the patella and down beside the patella tendon. The anterior lateral portion of the tibia is exposed and Gerdy’s tubercle and the attachment of the ilio-tibial tract identified. The incision is extended proximally around the patella and up into the extensor mechanism. Generous excision of the fat pad is required. If there is concern about the status of the ACL, this is assessed by pulling it with a hook. Osteophytes are removed from around the lateral condyle, the intercondylar notch, the anterior tibia and in front of the ACL on the tibia. If there are osteophytes on the lateral side of the patella, these are removed.
