Idiopathic Scoliosis: Rod Measurement and Placement
Surgical Technique for Anterior Thoracoscopic Correction of Idiopathic Scoliosis: Chapter 6
Rod Measurement and Placement
The rod length is determined with the Eclipse Rod Measurer. The fixed ball at the end of the measuring device is placed into the saddle of the inferior screw. The ball at the end of the cable is then guided through all of the screws with a pituitary to the superior most screw and inserted into the saddle (Fig. 21). The wire is then pulled tight and a reading is taken from the scale (Fig. 22). The scale is in centimeters.
|Figure 21||Figure 22|
The 4.5mm rod is then cut to length and inserted into the chest cavity through the inferior most port. The rod has a slight flexibility and is not bent prior to insertion. With the anterior compression, kyphosis is obtained in the thoracic spine. Do not cut rod longer than measured since the total distance between the screws will be reduced with compression. The rod is manipulated into the inferior screw with the Rod Holder (Fig. 23). The end of the rod should be flush with the saddle of the screw. This is done to prevent the rod from protruding and irritating or puncturing the diaphragm. Once the rod is in place, the portal is removed and the Plug Introduction Guide is placed over the screw to guide the plug and hold the rod into position (Fig. 24). The Obturator can be placed in the tube to assist in the insertion through the incision.
|Figure 23||Figure 24|
The plug is loaded onto the Plug-Inserter (Fig. 25). The plug must be inserted with the flat side with the laser etching up. Once the plug is placed on the driver turn the sleeve clockwise to engage the plug with the sleeve. The Plug Inserter is then placed through the Plug Introduction Guide and inserted into the screw. The plug should not be placed without using the Introduction Guide and the Plug Inserter. One turn counter clockwise before advancing the plug will assist in ensuring proper threading. Once the plug has been correctly started, hold the locking sleeve to prevent any further rotation. This will disengage the plug from the inserter as the plug is inserted into the screw (Fig. 26). Remove the driver and Introduction Guide and torque the screw with the Torque Limiting Wrench. This is the only plug that is tightened completely at this time.
|Figure 25||Figure 26||Figure 27|
The rod is then sequentially reduced into the remaining screws using the Rod Pushers (Fig. 27). The Rod Pushers should be placed on the rod several screws above the screw that the rod is being reduced into. This will assist in rod reduction. The plugs are applied through the Plug Introduction Guide as described above. These plugs should not be fully tightened at this time in order to allow for compression