Intraoperative imaging with Cios Spin

Intraoperative 3D imaging in orthopedic trauma surgeryAn experience report from BG Klinik Ludwigshafen, Germany

Conventional 2D intraoperative imaging does not always provide enough information to achieve the best possible results in orthopedic trauma surgery. Depending on the type and location of fractures, it can be tricky to assess whether a screw or wire is positioned correctly. If detected postoperatively, revision surgery will be necessary for some patients. Intraoperative 3D imaging enables the surgeon to correct malpositioned implants intraoperatively and not in a revision surgery.

High-quality 3D imaging

To assess joints and bones as quickly and reliably as possible, excellent image quality is of the utmost importance. With conventional imaging, the only way to assess the placement of an implant, screw, or fracture reduction in 3D is to acquire a postoperative CT. By then, however, it’s too late for corrections because patients would need to undergo a new anesthesia and surgery – with the risk of wound infection or longer hospital stay, just to name a few. Studies have shown that rates of correction after intraoperative 3D in calcaneus fractures, for example, are as high as 34.1%.

Intraoperative 3D imaging has proven its worth in clinical trials and case series around the world. When 3D scanning technology is applied across various fracture locations, intraoperative revisions are required in approx. 20% of patients. In calcaneal fractures, unstable syndesmotic injuries, tibia head fractures, and distal radius fractures type C, revision rates are considerably higher.

Metal artifact reduction case report

In a patient with a complex tibial head fracture, the bone fragments were repositioned using a metal plate and several screws. Thanks to the metal artifact reduction provided by Cios Spin, this very small fragment was clearly visible and the surgeon could see the correct position of the fragment and the joint surface.

16x16x16 FOV

Besides excellent image quality, Cios Spin also shows surgeons a large volume of the anatomical area that is covered by 3D – with a field of view of 16 cm in each direction. Compared with the predecessor system with a 12 cm field of view, this is more than twice as much in terms of volume.

Large 3D volume

In orthopedic trauma surgery, the 3D volume covered by the predecessor system is big enough for calcaneal and many other types of fractures. But it can be suboptimal in areas with larger bones, most notably in patients with pelvic or spinal fractures. For these cases, Cios Spin provides a large 3D volume of 16 cm x 16 cm x 16 cm.

Developed with the needs of the surgeon in mind

With Cios Spin, the surgeon does not pay for better accuracy with a longer procedure time. On the contrary, standard scanning time is as low as 30 seconds – whether 100, 200, or 400 projections are chosen. The iso-centric approach of the 3D scan around the patient makes handling the process much easier: With the help of orthogonal laser points, the anatomy of interest can be placed in the center of the 3D scan- making the collision check quick, easy and predictable.

93 cm open space

Among the limits of non-isocentric intraoperative 3D imaging are deficits in usability:

  • Cumbersome usability may lead to low or no usage of 3D scanning in daily routine
  • A small space between X-ray tube and detector limits flexibility during scanning – especially if instruments and implants are placed in that space during the scan

With 94 cm, Cios Spin offers a considerably large distance between X-ray tube and detector – making limited space and collisions less of an issue.

The surgeon’s little digital helper

Screw Scout

Screw Scout makes surgery more efficient and thus shorter: The algorithm automatically detects screws and presents them in the three relevant projections that are needed to assess correct positioning in a matter of seconds.

Target Pointer

Traget Pointer can help reduce the number of attempts to place k-wires.1) The auxiliary tool displays an overlay trajectory in 2D projections. In other words: It shows a virtual extension of linear metal objects like k-wires, so that surgeons can see the location they’re zeroing in on.

The patient’s perspective

The main priority for patients is high-quality surgical care. Intraoperative revision rates in patients with intraoperative 3D imaging are as high as 20% – 40%, depending on the location of the fracture. Without intraoperative 3D imaging, a relevant share of these patients would need postoperative revision surgery – especially patients with intraarticular implant misplacement.

In some of these patients, implant misplacement will be recognized on postoperative CT scans. In others, it will only become obvious weeks later, once the patient starts putting strain on the joint again. In both cases, a second surgical intervention is necessary – which always has the additional risk of an infection and the building of scar tissue. And it also means a second hospital stay for the patient. If implant misplacement is detected during the initial operation, however, there’s no need for a second anesthesia and surgery.

Calcaneal fracture case report

The young woman suffered a complicated calcaneal fracture after jumping from a high place. A screw was fitted to hold a fragment in place that was part of the proximal joint surface. Routine intraoperative 3D imaging showed that the screw protruded 3 mm into the joint. The screw was removed and replaced by another one that was 5 mm shorter. Without detection through intraoperative 3D imaging, the misplaced screw would have certainly caused severe pain, as it was on the proximal joint surface, an area with axial strain when standing or walking.

The healthcare provider’s perspective

Intraoperative imaging can save money

An investment in 3D imaging equipment is not just an investment in better quality of care. It is also an investment that can help a hospital save money. Screw misplacements, for example, can be corrected right away during surgery – making postoperative revision unnecessary and translating into much lower costs.4)

Jochen Franke, MD, BG Klinik Ludwigshafen