Inion S-2™ Surgical
18Pages

Graft Containment System Surgical Technique

Product Overview The Inion S-2™ Biodegradable Anterior Thoraco-Lumbar Fusion System for graft containment consists of plates and screws made of degradable co-polymers composed of L-lactic and D-lactic acid. These polymers have a long history of safe medical use and they degrade in vivo by hydrolysis into alpha-hydroxy acids that are metabolised by the body. Based on in vitro testing, the implants retain most of their initial strength up to 16 weeks and gradually lose their strength thereafter; and bioresorption takes place within two to four years. The plates and screws contain radiopaque...

Anterior approach to the lumbar spine True anterior Reaching the anterior aspect of the lumbar The patient is positioned supine on a radio-lucent spine poses certain challenges for the surgeon operating table, allowing both AP and lateral and should only be performed by those with C-arm fluoroscopy. A break in the table behind the experience of these approaches and the pitfalls lumbar spine may be useful to increase extension, that may be encountered. An access surgeon or, alternatively, a padded gel role may be used. should be considered for the less experienced This increases the lordotic...

Subcutaneous tissues are parted to expose the The rectus muscles are now parted in the midline, anterior rectus sheath, which is in turn opened typically with finger dissection only. Bleeding bilaterally in the line of the skin incision. The points are coagulated en route, care being taken underlying muscle must not be traumatised, as to avoid the inferior epigastric vascular bundle. bleeding vessels may retract and prove difficult The left rectus muscle is then elevated, a large to control. The two incisions in the sheath are Langenbeck type retractor may be used. Below joined across the...

Anterior approach to the lumbar spine As the spine is approached medial to the A straight, hand-held, Kelly retractor is useful for psoas muscle, the common iliac vessels will aiding visualisation. Steinman pins, preferably be is identified, together with the ureter and covered in silastic, may be tapped into the sympathetic trunk. The sympathetic trunk must vertebral bodies above and below the disc being be preserved and gently mobilised laterally. operated upon, to hold back the tissues and The ureter is usually mobilised medially with maintain retraction. Constant retraction over a the...

into the disc space using this approach. It does instrumentation to be used, the experience of the require a lot of retraction, pulling not only the surgeon and any prosthetics/implants planned. intra-peritoneal structures, but also the rectus The external and internal oblique muscles muscle and its sheath across the midline. This are opened in a “grid-iron” manner and the approach should, therefore, be reserved for cases transversus abdominis fibres are parted to enter where direct anterior placement of a device into the extra-peritoneal space. This is developed by the disc space is not...

Anterior approach to the lumbar spine Complications of the approaches There are complications and risks common to Vascular injury is not uncommon. If the disc is all of the above. Infection, haemorrhage and grossly inflamed, the vessels may be stuck to it a paralytic ileus are similar risks for all three and bleeding may occur, usually from a branch, approaches. A haematoma within the rectus when mobilising these. A suture on a round sheath can be very painful and present as an acute bodied needle, liga-clips or, if all else fails, a pin to abdomen. It is easy to diagnose on ultrasound. A...

Surgical technique 1. Determine the correct plate size 2. Mark screw holes with the Awl Once the graft is in place, the plate templates can After contouring the plate template use the awl to be used to determine the right size of Inion S-2™ mark screw hole locations. Use the depth markers plate. The plate holder can be used for positioning on the shaft of the awl to monitor the progress of the awl and ensure the desired depth is achieved. After the plate size is determined, pliers can be used to shape the plate template to fit the anatomical contours of spine. The contoured plate template...

Surgical technique 3. Contour the Inion S-2™ plate 4. Place the plate on the bone with the Temporary Fixation Screws Precondition the chosen Inion S-2™ plate in the Using the plate holder, place the contoured Inion Inion Thermo+™ water bath for a minimum of S-2™ plate at the desired level and insert at least one temporary fixation screw to each end of the plate, ideally in opposing screw holes. Use the contoured plate template (from Step 1) or plate contouring block to shape the Once the plate is fixed into position, with preconditioned plate to the desired shape. temporary screws, the...

5. Drill the screw hole It is advised that you always use the drill guide As with in step 5 it is advised that you always use whenever preparing screw holes in the Inion S-2™ the drill guide when ever tapping the screw holes plate. This allows the correct screw trajectory and in the Inion S-2™ plate. This allows the correct depth to be achieved as well as ensuring the plate screw trajectory and depth to be maintained as is sufficiently seated to the bone. The drill bits are well as ensuring the plate is sufficiently seated to colour coded. Each colour corresponds to a screw the bone. The...

Surgical technique 7. Insert the first Inion S-2™ screw Load the desired Inion S-2™ screw on to the It is advised that you always use the drill guide screwdriver supplied. Ensure the screw is seated when inserting screws into the Inion S-2™ plate. by applying a firm downward pressure when This allows the correct screw trajectory and depth engaging the screwdriver shaft into the Inion to be achieved as well as ensuring the plate is S-2™ screw head. sufficiently seated to the bone. Pass the screw through the drill guide until you feel it locate the plate.