Flat-panel-Technologie im orthopädisch-unfallchirurgischen Operationssaal

Software-Automated Implant Detection for Intraoperative 3D Imaging-First Clinical Evaluation on 214 Data Sets

Previous studies have demonstrated a frequent occurrence of screw/K-wire malpositioning during surgical fracture treatment under 2D fluoroscopy and a correspondingly high revision rate as a result of using intraoperative 3D imaging. In order to facilitate and accelerate the diagnosis of implant malpositioning in 3D data sets, this study investigates two versions of an implant detection software for mobile 3D C-arms in terms of their detection performance based on comparison with manual evaluation. The 3D data sets of patients who had received surgical fracture treatment at five anatomical regions were extracted from the research database. First, manual evaluation of the data sets was performed, and the number of implanted implants was assessed. For 25 data sets, the time required by four investigators to adjust each implant was monitored. Subsequently, the evaluation was performed using both software versions based on the following detection parameters: true-positive-rate, false-negative-rate, false-detection-rate and positive predictive value. Furthermore, the causes of false positive and false negative detected implants depending on the anatomical region were investigated. Two hundred fourteen data sets with overall 1767 implants were included. The detection parameters were significantly improved (p<.001) from version 1 to version 2 of the implant detection software. Automatic evaluation required an average of 4.1±0.4 s while manual evaluation was completed in 136.15±72.9 s (p<.001), with a statistically significant difference between experienced and inexperienced users (p=.005). In summary, version 2 of the implant detection software achieved significantly better results. The time saved by using the software could contribute to optimizing the intraoperative workflow.

Evolution of imaging in surgical fracture management

Intraoperative imaging has been advanced substantially over the last decades. It supports localization of the region of interest, verification of the preoperatively classified fracture pattern, identification of correct insertion point of the implant, placement of instruments and fixation material, and verification of correct fracture reduction and implant positioning. While conventional fluoroscopic 2D imaging remains the gold standard in intraoperative imaging, critical anatomical regions are predestined for intraoperative 3D imaging. Additional options such as perioperative virtual planning, simulation, and surgical training, 3D printing techniques and 3D augmented reality visualization may potentially open new windows to improve surgical results in fracture care. This manuscript presents an update on current and upcoming imaging techniques in orthopaedic and trauma surgery focusing on technical advances for decreasing malreduction, malalignment, and malposition, as well as tips and tricks for daily surgical practice in order to improve clinical outcomes and patients' and surgeons' safety.

[Intraoperative 3D imaging in spinal surgery]

BACKGROUND

Intraoperative imaging during spinal interventions has experienced significant developments over the last two decades. By the introduction of flat screen detectors, 3D imaging has been made possible and easier and by developing compact and mobile systems computed tomography can even be used in the operating theater.

OBJECTIVE

Presentation of modern intraoperative 3D imaging and navigation in spinal surgery.

MATERIAL AND METHODS

The techniques of intraoperative 3D imaging and navigation during spinal procedures are presented based on the currently available literature and own experiences at a German national spine and trauma center.

RESULTS

The use of flat panel detectors and the possibility of 3D visualization nowadays substantially facilitate the use of navigation and allow certain control of surgical results even during the intervention. Radiation exposure of the whole team in the operating theater can be significantly reduced by the new techniques.

CONCLUSION

The advantages of intraoperative 3D imaging with a clear improvement of visualization for spinal surgeons and the certain control of materials at the end of the operation are obvious. Even the use of navigation has been greatly simplified and can therefore lead to an even greater precision and less radiation exposure. There are even more sophisticated developments, such as operation suites and intraoperative computed tomography but these are initially reserved for selected centers.

Navigated vs arthroscopic-guided drilling for reconstruction of acromioclavicular joint injuries: accuracy and feasibility

BACKGROUND

Anatomical reconstruction of the coracoclavicular ligaments is a relatively new technique for acromioclavicular (AC) joint injuries.

METHODS

Eighteen procedures (nine non-navigated, nine navigated) of anatomical reconstruction were performed minimally invasively, using the Tight Rope system, on cadaveric shoulders. Two Kirschner wires were placed, freehand under fluoroscopic control (non-navigated) or 3D C-arm navigated. The insertion point on the clavicle as well as the position of the K-wire in the coracoid were measured in the axial and coronal planes; points were assigned for different zones. For statistical analysis, the significance level was set to p = 0.05.

RESULTS

The accuracy of the entry point in the clavicle was significantly more accurate for the conoidal (p = 0.022) and trapezoidal ( p = 0.0062) drillings. The positioning in the coronal (p = 0.037) and axial (p = 0.0416) planes also showed higher accuracy for the navigated procedures.

CONCLUSION

The accuracy of anatomical AC joint reconstruction can be improved using 3D C-arm flat detector navigation.