Incisions may be developed in different manners. Two alternatives will be described below.
Alternative 1: 方案1
The tip of the greater trochanter may be located by palpation (Fig. 13) and a horizontal skin incision of approximately 2−3cm is made from the greater trochanter in the direction of the iliac crest (Fig. 14). In larger patients the incision length may need to be longer, depending on BMI of the patient.
A small incision is deepened through the fascia lata, splitting the gluteal muscle approximately 1−2cm immediately above the tip of the greater trochanter, thus exposing its tip. A self-retaining retractor, or tissue protection sleeve is put in place.
A long and thin metal rod (e. g. screw scale, long) is placed on the lateral side of the leg. Check with the image intensifier, using M-L view, that the metal rod is positioned parallel to the bone in the center of the proximal part of the femoral canal (Fig. 16a). A line is drawn on the skin (Fig. 16).
The C-arm is turned approx 90° to provide an A/P image of the tip of the trochanter using the metal rod as shown in Figure 17 and 17a. A vertical line is drawn onto the skin (Fig. 18). The intersection of the lines indicates the position for the entry point of the nail. This is usually the anterior third of the tip of the greater trochanter as shown in Fig. 19.
The skin incision is made cranially to the indicated intersection, following the sagittal line in cranial direction. The distance between the intersection and the starting point for the incision differs, depending on the obesity of the patient. Under normal conditions it is a distance of approximately 2cm’s.
A small skin incision is made as described in alternative 1 and shown in Fig. 20.
Using a finger, the tip of the trochanter should be felt easily (Fig. 21).
Entry point 进针点
The correct entry point is located at the junction of the anterior third and posterior two-thirds of the tip of the greater trochanter and on the tip itself (Fig. 22).
Opening the cortex 打开皮质
The medullary canal has to be opened under image intensification. The use of the cannulated curved awl (Fig. 23) is recommended if conventional reaming or the One Step Conical Reamer will be used to prepare the canal for the nail.
During opening the entry point with the awl, dense cortex may block the tip of the awl.
An awl plug can be inserted through the awl to avoid penetration of bone debris into the cannulation of the awl shaft.
The optional rasp awl combines the feature of the rasp and awl to prepare the proximal femur for the Gamma3 Nail. It may provide an option to open the proximal femur cavity without further reaming (Fig.24).