Kosten- und Nutzenanalyse der intraoperativen 3D-Bildgebung

[Innovative 3D imaging]

Intraoperative 2D fluoroscopy is often performed for repositioning and implant control. However, this does not always provide the details needed to reliably detect joint steps or incorrect repositioning. Over the last few years, intraoperative 3D imaging has been established and further developed. Multiple studies demonstrate an advantage and better intraoperative control through 3D imaging. Examples are the upper ankle, the proximal tibia and the distal radius; the rates of intraoperative revisions with digital volume tomography (DVT) are between 20-30%. Technical advancements, such as metal artifact reductions, automated plane setting, automated screw detection, and robotic DVT devices, facilitate intraoperative operation, shorten surgical time, and provide improved image quality. By processing the data sets in the form of an immersive, computer-simulated image in terms of "augmented reality" (AR), increased precision can be achieved intraoperatively while reducing radiation exposure. The implementation of these systems is associated with costs, which are offset by cost savings from avoided revisions. Adequate counter-financing is still lacking at the present time. Intraoperative 3D imaging represents an important tool for intraoperative control. The current data situation makes it necessary to address the routine use of 3D procedures, especially in the joint area. The indications are becoming increasingly broader. Technical innovations such as robotics and AR have significantly improved 3D devices in recent years and offer high potential for integration into the OR.

Does the intraoperative 3D-flat panel control of the planned implant position lead to an optimization and increased in safety in the anatomically demanding region C1/2?

BACKGROUND

The aim of this study was to evaluate the applicability and advantages of intraoperative imaging using a 3D flat panel in the treatment of C1/2 instabilities.

MATERIALS

Prospective single-centered study including surgeries at the upper cervical spine between 06/2016 and 12/2018. Intraoperatively thin K-wires were placed under 2D fluoroscopic control. Then an intraoperative 3D-scan was carried out. The image quality was assessed based on a numeric analogue scale (NAS) from 0 to 10 (0 = worst quality, 10 = perfect quality) and the time for the 3D-scan was measured. Additionally, the wire positions were evaluated regarding malpositions.

RESULTS

A total of 58 patients were included (33f, 25 m, average age 75.2 years, r.:18-95) with pathologies of C2: 45 type II fractures according to Anderson/D'Alonzo with or without arthrosis of C1/2, 2 Unhappy triad of C1/2 (Odontoid fracture Type II, anterior or posterior C1 arch-fracture, Arthrosis C1/2) 4 pathological fractures, 3 pseudarthroses, 3 instabilities of C1/2 because of rheumatoid arthritis, 1 C2 arch fracture). 36 patients were treated from anterior [29 AOTAF (combined anterior odontoid and transarticular C1/2 screw fixation), 6 lag screws, 1 cement augmented lag screw] and 22 patients from posterior (regarding to Goel/Harms). The median image quality was 8.2 (r.: 6-10). In 41 patients (70.7%) the image quality was 8 or higher and in none of the patients below 6. All of those 17 patients the image quality below 8 (NAS 7 = 16; 27.6%, NAS 6 = 1, 1.7%), had dental implants. A total of 148 wires were analyzed. 133 (89.9%) showed a correct positioning. In the other 15 (10.1%) cases a repositioning had to be done (n = 8; 5.4%) or it had to be drawn back (n = 7; 4.7%). A repositioning was possible in all cases. The implementation of an intraoperative 3D-Scan took an average of 267 s (r.: 232-310 s). No technical problems occurred.

CONCLUSION

Intraoperative 3D imaging in the upper cervical spine is fast and easy to perform with sufficient image quality in all patients. Potential malposition of the primary screw canal can be detected by initial wire positioning before the Scan. The intraoperative correction was possible in all patients. Trial registration German Trials Register (Registered 10 August 2021, DRKS00026644-Trial registration: German Trials Register (Registered 10 August 2021, DRKS00026644- https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00026644 ).

Intraoperative revision rates due to three-dimensional imaging in orthopedic trauma surgery: results of a case series of 4721 patients

PURPOSE

Intraoperative 3D imaging has become a valued tool in assessing the quality of reduction and implant placement in orthopedic trauma surgery. In our institution, 3D imaging is used routinely since 2001. To evaluate the intraoperative findings and consequences of this technique, intraoperative revision rates in cases with 3D imaging were analyzed.

METHODS

All operative procedures carried out with intraoperative 3D imaging between August 2001 and December 2016 were included. The scans were assessed intraoperatively and documented thereafter. In case of malreduction or misplaced implants, an immediate revision was performed. The number of scans per case as well as the findings and consequences drawn regarding the anatomical region were analyzed.

RESULTS

4721 cases with 7201 3D scans were included in this study. The most common anatomical regions were the ankle (22.3%), the calcaneus (14.8%) and the tibial head (9.5%). In 19.1% of all cases, an intraoperative revision was performed. The highest revision rates were found with 36.0% in calcaneal fractures, 24.8% in fractures of the tibial plateau, 22.3% in injuries of the ankle. In 52.0% of revisions, the reduction was improved regarding intra-articular steps or joint congruency. In 30.5% an implant was corrected.

CONCLUSION

Intraoperative revision due to results of 3D imaging was performed in almost one-fifth of cases. This illustrates the improved possibilities to detect malreduction and implant misplacements intraoperatively and thus the abilities to improve surgical outcome.

LEVEL OF EVIDENCE

III.

Fluoroscopic imaging: New advances

Today's orthopedic surgery could not be imagined without intraoperative x-ray-based imaging. This enables surgeons to assess operative interim steps as well as the result before wound closure and finishing the procedure. Although there have been mobile C-arms used for decades, there are recent advances that do not only affect the quality of the imaging itself but also the way, the information is processed and presented. These very exciting developments will change the integration of imaging into the surgical workflows, giving options of augmented reality, reduction of radiation dose, automatized acquisition and analysis of images and low-level guidance in procedures. This paper gives a review of current innovations and possible future trends in fluoroscopic 2D and 3D imaging.

[Does navigation still have a value in trauma surgery?]

BACKGROUND

Navigation systems are supposed to increase precision and support surgeons while they perform certain interventions. 2D, or nowadays 3D, systems are used in image-based approaches. Image-free navigation uses 3D printing.

INDICATIONS

There are several studies on navigation procedures in trauma surgery. In contrast to limb surgery, the use of 3D navigation in pelvic and spine surgery is already well established. Navigation is especially regularly used to treat fractures of the posterior pelvic ring and for posterior stabilization of the cervical spine.

REQUIREMENTS

To be able to utilize navigation systems optimally, the learning curve should be completed, and the technique should be used regularly. In addition, the surgeon should know the surgical technique without navigation in order to recognize potential errors of the navigation.

ADVANTAGES AND DISADVANTAGES

Advantages include increased patient safety, reduction in radiation exposure and less invasive surgical procedures. However, among other disadvantages, initial costs are high.

Computer-Assisted Orthopedic and Trauma Surgery

BACKGROUND

There are many ways in which computer-assisted orthopedic and trauma surgery (CAOS) procedures can help surgeons to plan and execute an intervention.

METHODS

This study is based on data derived from a selective search of the literature in the PubMed database, supported by a Google Scholar search.

RESULTS

For most applications the evidence is weak. In no sector did the use of computer-assisted surgery yield any relevant clinical or functional improvement. In trauma surgery, 3D-navigated sacroiliac screw fixation has become clinically established for the treatment of pelvic fractures. One randomized controlled trial showed a reduction in the rate of screw misplacement: 0% with 3D navigation versus 20.4% with the conventional procedure und 16.6% with 2D navigation. Moreover, navigation-assisted pedicle screw stabilization lowers the misplacement rate. In joint replacements, the long-term results showed no difference in respect of clinical/functional scores, the time for which the implant remained in place, or aseptic loosening.

CONCLUSION

Computer-assisted procedures can improve the precision of certain surgical interventions. Particularly in joint replacement and spinal surgery, the research is moving away from navigation in the direction of robotic procedures. Future studies should place greater emphasis on clinical and functional results.

Diagnosis of dorsal screw penetration after volar plating of a distal radial fracture

Aims

The aim of this study was to investigate whether intraoperative 3D fluoroscopic imaging outperforms dorsal tangential views in the detection of dorsal cortex screw penetration after volar plating of an intra-articular distal radial fracture, as identified on postoperative CT imaging.

Methods

A total of 165 prospectively enrolled patients who underwent volar plating for an intra-articular distal radial fracture were retrospectively evaluated to study three intraoperative imaging protocols: 1) standard 2D fluoroscopic imaging with anteroposterior (AP) and elevated lateral images (n = 55); 2) 2D fluoroscopic imaging with AP, lateral, and dorsal tangential views images (n = 50); and 3) 3D fluoroscopy (n = 60). Multiplanar reconstructions of postoperative CT scans served as the reference standard.

Results

In order to detect dorsal screw penetration, the sensitivity of dorsal tangential views was 39% with a negative predictive value (NPV) of 91% and an accuracy of 91%; compared with a sensitivity of 25% for 3D fluoroscopy with a NPV of 93% and an accuracy of 93%. On the postoperative CT scans, we found penetrating screws in: 1) 40% of patients in the 2D fluoroscopy group; 2) in 32% of those in the 2D fluoroscopy group with AP, lateral, and dorsal tangential views; and 3) in 25% of patients in the 3D fluoroscopy group. In all three groups, the second compartment was prone to penetration, while the postoperative incidence decreased when more advanced imaging was used. There were no penetrating screws in the third compartment (extensor pollicis longus groove) in the 3D fluoroscopy groups, and one in the dorsal tangential views group.

Conclusion

Advanced intraoperative imaging helps to identify screws which have penetrated the dorsal compartments of the wrist. However, based on diagnostic performance characteristics, one cannot conclude that 3D fluoroscopy outperforms dorsal tangential views when used for this purpose. Dorsal tangential views are sufficiently accurate to detect dorsal screw penetration, and arguably more efficacious than 3D fluoroscopy. Cite this article: Bone Joint J 2020;102-B(7):874–880.

Effect of different multiplanar reformation algorithms on image quality of intraoperative three-dimensional fluoroscopy

Different multiplanar reformation (MPR-512 and -256) algorithms of intraoperative acquired 3-D-fluoroscopy data exist without recommendations for use in the literature. To compare algorithms, 3-D-fluoroscopic data sets of 46 radius fractures were blinded and processed using MPR-256 and -512 (Ziehm, Vision-Vario 3D). Each reformatted data set was analysed to evaluate image quality, fracture reduction quality and screw misplacements. Overall image quality was higher rated in the MPR-512 compared with the MPR-256 (3.2 vs. 2.2 points, scale 1-5 points), accompanied by a reduced number of scans that could not be analysed (10 vs. 19%). Interobserver evaluation of fracture reduction quality was fair to moderate (independent of the algorithm). In contrast, for screw misplacements MPR-depended ratings were found (MPR-256: fair to moderate; MPR-512: moderate to substantial). Optimization of post-processing algorithms, rather than modifications of image acquisition, may increase the image quality for assessing implant positioning, but limitations in evaluating fracture reduction quality still exist.

[Hybrid operating room : Application in trauma surgery and orthopaedics]

BACKGROUND

For some years now, more and more hospitals in Germany have acquired so-called hybrid operating rooms. In these operating rooms it is possible to produce three-dimensional imaging during the operation. Originally developed for cardiovascular surgery, these rooms are increasingly being used for interdisciplinary purposes. Previous experiences in the use for trauma surgery and orthopedics has shown that three-dimensional imaging can have a positive effect on the success of surgery.

OBJECTIVE

Can minimally invasive operations on the spine benefit intraoperatively from three-dimensional imaging with respect to operating times and results?

METHODS

Minimally invasive operations on the spine performed at the UKSH Campus Kiel between 2015 and 2018 in the hybrid operating room were considered. These were compared to minimally invasive spinal surgery performed in conventional operating rooms.

RESULTS

As is usual with the establishment of a new procedure, there are initially longer operating times. With regular use and appropriate training and experience of the personnel, the processes can be optimized.

CONCLUSION

Due to the accuracy of the three-dimensional imaging, errors can be detected and eliminated at an early stage during the operation. Revisions are less frequent. In contrast, there is increased radiation exposure and sometimes longer operation and anesthesia times.

Comparison of intraoperative 2D vs. 3D imaging in open reduction and fixation of distal radius fractures

PURPOSE

In the volar plating of distal radius fractures, intraoperative three-dimensional (3D) imaging is designed to allow better judgment regarding screw and implant positioning compared with conventional intraoperative two-dimensional (2D) imaging. We evaluated the impact of these two imaging modalities on the rates of intraoperative revision and secondary surgery, as well as the need for implant removal during follow-up.

METHODS

A retrospective analysis of consecutive patients who underwent volar plate osteosynthesis for isolated distal radius fractures between January 2008 and April 2016 was performed. Patient files were evaluated for intraoperative imaging findings, intraoperative and postoperative revision rates, and implant removal during follow-up. Additional analyses of radiation exposure, operation time, and hospitalization time were performed.

RESULTS

A total of 314 patients were analyzed (mean age: 54 ± 19 years; 210 females). For 246 patients, only 2D imaging was performed, while the remaining 68 patients underwent both 2D and 3D imaging (O-Arm, Medtronic). The intraoperative revision rate was significantly (p < 0.001) higher with 3D imaging (32.4%) compared with 2D imaging (2.0%). The postoperative revision rates were similar between both the groups (2.9% vs. 2.0%; p = 0.674). Compared with 2D imaging, the use of the Medtronic O-Arm resulted in a significantly lower implant removal rate (8.8% vs. 18.7%; p = 0.036) during follow-up.

CONCLUSION

Compared with conventional 2D imaging, the use of intraoperative 3D imaging significantly increased the intraoperative revision rate and has the potential for positive long-term effects for lowering the risk of requiring an implant removal.

Intraoperative three-dimensional imaging in the treatment of distal radius fractures

INTRODUCTION

In operative treatment of distal radius fractures satisfying outcome mainly relies on anatomical fracture reduction and correct implant placement. Examination with two-dimensional fluoroscopy may not provide reliable information about this. The aim of this study was to determine the effectiveness of additional intraoperative three-dimensional imaging in the operative treatment of comminuted distal radius fractures.

MATERIALS AND METHODS

From August 2001 to June 2015, patients with a distal radius fracture who were treated operatively and received intraoperative three-dimensional scan were included. The findings of the three-dimensional scan were documented by the operative surgeon and analyzed retrospectively with regard to incidence and the need for intraoperative revisions. Clinical evaluation included the patient's medical history, the injury pattern of the affected wrist (according to the OTA/AO fracture classification) and concomitant injuries. Intraoperative and postoperative complications and revision surgeries were evaluated as well.

RESULTS

Of 4515 operatively treated distal radius fractures, 307 (6.8%) received additional intraoperative three-dimensional imaging during surgery. 263 of 307 patients (85.7%) had a distal radius fracture type C. Intraoperative three-dimensional imaging revealed findings in 125 patients (40.7%) that were not detected on conventional two-dimensional fluoroscopy. In 54 patients (17.6%) these findings led to an immediate revision. Most commonly, revision was done in the case of remaining steps in the articular surface ≥ 1 mm (n = 25, 8.1%) followed by intra-articular screw placement (n = 23, 7.5%).

CONCLUSIONS

Intraoperative three-dimensional imaging can provide additional information compared to conventional two-dimensional fluoroscopy in the operative treatment of distal radius fractures with the possibility of immediate intraoperative revision.

Total Disc Replacement Versus Anterior-Posterior Interbody Fusion in the Lumbar Spine and Lumbosacral Junction: A Cost Analysis

STUDY DESIGN

Prospective observational cohort study.

OBJECTIVES

To analyze clinical and economic results in patients with degenerative disc disease in the lumbar area for patients who received combined anterior and posterior fusion or total disc replacement (TDR).

METHODS

The study included 75 patients, 38 in the fusion group and 37 in the TDR group, who received either anterior/posterior fusion or TDR for lumbar disc disease from January 2005 to December 2008 with a minimum follow-up of 24 months. We collected data with regard to clinical parameters, demographics, visual analogue scale scores, Oswestry Disability Index scores, SF-36 and SF-6D data, surgery time, amount of blood loss, transfusion of blood products, number of levels, duration of hospital stay, and complications. For cost analysis, general infrastructure, theatre costs, as well as implant costs were examined, leading to primary hospital costs. Furthermore, average revision costs were examined, based on the actual data. Statistical analysis was performed using t tests for normal contribution and Mann-Whitney test for skew distributed values. The significance level was set to .05.

RESULTS

There was a higher surgery time, more blood loss, and longer hospital stay for the fusion group, compared with the TDR group. In addition, the hospital costs for the primary procedure and revision were 35% higher in the fusion group. The clinical data in terms of SF-36 and SF-6D showed no difference between these 2 groups.

CONCLUSIONS

TDR is a good alternative to anterior and posterior lumbar fusion in terms of short follow-up analysis for clinical data and cost analysis. General advice cannot be given due to missing data for long-term costs in terms of surgical treatment of adjacent level or further fusion techniques.

Detection of articular perforations of the proximal humerus fracture using a mobile 3D image intensifier - a cadaver study

Background

The purpose of this study was to investigate the accuracy of perforation detection with multiplanar reconstructions using a mobile 3D image intensifier.

Methods

In 12 paired human humeri, K-wires perforating the subchondral bone and placed just below the cartilage level were directed toward five specific regions in the humeral head. Image acquisition was initiated by a fluoroscopy scan. Within a range of 90°, 45° external rotation (ER) and 45° internal rotation (IR). The number and percentage of detected perforating screws were grouped and analyzed. Furthermore, the fluoroscopic images were converted into multiplanar CT-like reconstructions. Each K-wire perforation was characterized as “detected” or “not detected”.

Results

In the series of fluoroscopy images in the standard neutral position at 30° internal rotation, and 30° external rotation, the perforations of all K-wires (n = 56) were detected. Twenty-nine (51.8%) of them were detected in one AP view, 22 (39.3%) in two AP views, and five (8.9%) in three AP views. All K-wire perforations (100%, n = 56) were detected in multiplanar reconstructions.

Conclusion

In order to reveal all of the intraoperative and postoperative screw perforations in a “five screw configuration”, conventional AP images should be established in both the neutral positions (0°), at 30° internal rotation and 30° external rotation. Alternatively, the intraoperative 3D scan with multiplanar reconstructions enables a 100% rate of detection of the screw perforations.

[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.

Preclinical usability study of multiple augmented reality concepts for K-wire placement

PURPOSE

In many orthopedic surgeries, there is a demand for correctly placing medical instruments (e.g., K-wire or drill) to perform bone fracture repairs. The main challenge is the mental alignment of X-ray images acquired using a C-arm, the medical instruments, and the patient, which dramatically increases in complexity during pelvic surgeries. Current solutions include the continuous acquisition of many intra-operative X-ray images from various views, which will result in high radiation exposure, long surgical durations, and significant effort and frustration for the surgical staff. This work conducts a preclinical usability study to test and evaluate mixed reality visualization techniques using intra-operative X-ray, optical, and RGBD imaging to augment the surgeon's view to assist accurate placement of tools.

METHOD

We design and perform a usability study to compare the performance of surgeons and their task load using three different mixed reality systems during K-wire placements. The three systems are interventional X-ray imaging, X-ray augmentation on 2D video, and 3D surface reconstruction augmented by digitally reconstructed radiographs and live tool visualization.

RESULTS

The evaluation criteria include duration, number of X-ray images acquired, placement accuracy, and the surgical task load, which are observed during 21 clinically relevant interventions performed by surgeons on phantoms. Finally, we test for statistically significant improvements and show that the mixed reality visualization leads to a significantly improved efficiency.

CONCLUSION

The 3D visualization of patient, tool, and DRR shows clear advantages over the conventional X-ray imaging and provides intuitive feedback to place the medical tools correctly and efficiently.

Intraoperative 3D imaging in the treatment of elbow fractures--a retrospective analysis of indications, intraoperative revision rates, and implications in 36 cases

Background

Three-dimensional (3D) imaging with a mobile C-arm has proven to be a valuable intraoperative tool in trauma surgery. However, little data is available concerning its use in the treatment of elbow fractures. The aim of the current study was to determine the intraoperative findings and consequences of 3D imaging in the treatment of elbow fractures.

Methods

Between 2001 and 2015, prospectively collected data of 36 patients who underwent intraoperative 3D imaging during elbow surgery were recorded. The findings and consequences of the intraoperative 3D scans were analyzed in a retrospective chart review. For clinical evaluation the analysis included the patients’ medical history, the injury pattern of the affected elbow and concomitant injuries. Intraoperative and postoperative complications and revision surgeries were evaluated as well.

Results

In 6 patients (16.7 %) analysis of the intraoperative 3D scan led to an immediate revision due to the detection of intra-articular screw placement (n = 3, 8.3 %) and remaining intra-articular step of >2 mm (n = 3, 8.3 %). In all of these patients, correct implant positioning and anatomical reduction could be achieved after immediate intraoperative revision, which was verified by a repeated intraoperative 3D scan. None of the 36 patients needed surgical revision based on postoperative radiological examinations due to secondary dislocation, wrong implant placement or remaining steps in the articular surface.

Conclusions

Intraoperative 3D imaging offers additional information about fracture reduction and implant positioning in the treatment of elbow fractures compared to conventional intraoperative 2D imaging. It may therefore reduce the need for revision surgery. The value of intraoperative 3D imaging for clinical outcomes still needs to be assessed.

Intraoperative Three-Dimensional Imaging in Calcaneal Fracture Treatment

Background

To compare the effectiveness of intraoperative three-dimensional (3D) image and conventional two-dimensional (2D) fluoroscopic images, which are used in the treatment of acute calcaneal fractures.

Methods

We retrospectively analyzed 40 patients who suffered calcaneal fracture and underwent surgery at Inje University Busan Paik Hospital. The patients were divided into two groups. Only 2D fluoroscopy was used to evaluate 20 patients of group 1. On the other hand, 3D fluoroscopy was performed on the remaining 20 patients of group 2; 3D fluoroscopy was performed on these patients after they were extensively evaluated by 2D fluoroscopy during surgery. We reviewed the radiographic and clinical outcomes of these patients, whose average follow-up period was 42.6 months.

Results

In group 2, 3D fluoroscopy detected four cases (20%) of articular incongruence and screw misplacement. All these complicated cases were corrected during surgery. At the final follow-up session, the mean American Orthopedic Foot and Ankle Society (AOFAS) hind foot score was 78.3 (range, 65 to 95) in group 1 and 82.3 (range, 68 to 95) in group 2.

Conclusions

Intraoperative 3D imaging of calcaneal fractures is considered to be useful in evaluating the congruence of joints and the placement of implants.

Tangential View and Intraoperative Three-Dimensional Fluoroscopy for the Detection of Screw-Misplacements in Volar Plating of Distal Radius Fractures

Background:

Volar locking plate fixation has become the gold standard in the treatment of unstable distal radius fractures. Juxta-articular screws should be placed as close as possible to the subchondral zone, in an optimized length to buttress the articular surface and address the contralateral cortical bone. On the other hand, intra-articular screw misplacements will promote osteoarthritis, while the penetration of the contralateral bone surface may result in tendon irritations and ruptures. The intraoperative control of fracture reduction and implant positioning is limited in the common postero-anterior and true lateral two-dimensional (2D)-fluoroscopic views. Therefore, additional 2D-fluoroscopic views in different projections and intraoperative three-dimensional (3D) fluoroscopy were recently reported. Nevertheless, their utility has issued controversies.

Objectives:

The following questions should be answered in this study; 1) Are the additional tangential view and the intraoperative 3D fluoroscopy useful in the clinical routine to detect persistent fracture dislocations and screw misplacements, to prevent revision surgery? 2) Which is the most dangerous plate hole for screw misplacement?

Patients and Methods:

A total of 48 patients (36 females and 13 males) with 49 unstable distal radius fractures (22 x 23 A; 2 x 23 B, and 25 x 23 C) were treated with a 2.4 mm variable angle LCP Two-Column volar distal radius plate (Synthes GmbH, Oberdorf, Switzerland) during a 10-month period. After final fixation, according to the manufactures' technique guide and control of implant placement in the two common perpendicular 2D-fluoroscopic images (postero-anterior and true lateral), an additional tangential view and intraoperative 3D fluoroscopic scan were performed to control the anatomic fracture reduction and screw placements. Intraoperative revision rates due to screw misplacements (intra-articular or overlength) were evaluated. Additionally, the number of surgeons, time and radiation-exposure, for each step of the operating procedure, were recorded.

Results:

In the standard 2D-fluoroscopic views (postero-anterior and true lateral projection), 22 screw misplacements of 232 inserted screws were not detected. Based on the additional tangential view, 12 screws were exchanged, followed by further 10 screws after performing the 3D fluoroscopic scan. The most lateral screw position had the highest risk for screw misplacement (accounting for 45.5% of all exchanged screws). The mean number of images for the tangential view was 3 ± 2.5 images. The mean surgical time was extended by 10.02 ± 3.82 minutes for the 3D fluoroscopic scan. An additional radiation exposure of 4.4 ± 4.5seconds, with a dose area product of 39.2 ± 14.5 cGy/cm² were necessary for the tangential view and 54.4 ± 20.9 seconds with a dose area product of 2.1 ± 2.2 cGy/cm², for the 3D fluoroscopic scan.

Conclusions:

We recommend the additional 2D-fluoroscopic tangential view for detection of screw misplacements caused by overlength, with penetration on the dorsal cortical surface of the distal radius, predominantly observed for the most lateral screw position. The use of intraoperative 3D fluoroscopy did not become accepted in our clinical routine, due to the technical demanding and time consuming procedure, with a limited image quality so far.

[Multiplanar reconstruction with mobile 3D image intensifier. Surgical treatment of proximal humerus fractures]

PURPOSE

The aim of this study was to analyze the applicability and advantages of the intraoperative use of a mobile 3D C-arm with multiplanar imaging for surgery of acute proximal humerus fractures.

MATERIALS AND METHODS

In this study 20 patients (11 female, 9 male, median age 70 years, range 35-91 years) with dislocated proximal humerus fractures (6 with 2 segments, 10 with 3 segments and 4 with 4 segments) were included. Preoperatively 3D scanning was performed and a reevaluation of the fracture in comparison to the plain radiographs was performed. After operative treatment another scan was performed to evaluate technical complications.

RESULTS

In comparison to the multiplanar reconstructions fracture morphology could not be correctly detected in 5 out of the 20 cases with plain radiographs. The preoperative image quality of the multiplanar reconstructions showed a significantly better assessment in comparison to the image quality with osteosynthesis (p < 0.05). The screws had to be replaced in 5 of the 20 patients.

CONCLUSION

Intraoperative 3D imaging with mobile image intensifier enables an accurate analysis of fracture morphology. Furthermore a quasi real time preoperative planning, evaluation of reduction and implant position with immediate operative relevance can be realized.

Intraoperative C-arm CT imaging in angular stable plate osteosynthesis of distal radius fractures

The purpose of this study was to analyze the practicability and benefit of intraoperative C-arm computed tomography (CT) imaging in volar plate osteosynthesis of unstable distal radius fractures. During a 1 year period, intraoperative three dimensional (3D) imaging with the ARCADIS Orbic 3D was performed in addition to standard fluoroscopy in 51 cases. The volar angular stable plate oesteosyntheses were analyzed intraoperatively and, if necessary, improved immediately. The duration of the scan and radiation exposure dose were measured. On average, performance of the scan and analysis of the CT dataset took 6.7 minutes. In 31.3% of the surgeries a misplacement of screws was detected and correction was done immediately. C-arm CT imaging can easily be integrated in the normal course of surgery. As a complement to the standard 2D-fluoroscopy, the C-arm CT is a useful tool to evaluate the quality of osteosynthesis.

[Intraoperative 3D C-arm imaging. State of the art]

Mobile C-arms with the option of 3D imaging like the Iso-C(3D) allow for intraoperative 3D visualization of anatomical areas with complex three-dimensional structures like articular surfaces. In an 8-year period we performed 1,841 intraoperative control scans following osteosynthesis. Among these patients we registered the number of intraoperative adjustments of fracture reduction and implant position in correlation to the area of surgery. The majority of intraoperative examinations in 1,841 patients was performed in fractures of the calcaneus (20.5%) and the upper ankle joint (13.2%). Altogether we improved the reduction or the implant position intraoperatively in 21.5%. The majority of intraoperative revisions was seen in osteosynthesis of the calcaneus (40.3%), the upper ankle joint (30.9%) and fractures of the distal tibia (29%). The rate of revisions over the time was very stable. Intraoperative need for revision of reduction or implant position is not a rare phenomenon in our experience. Intraoperative 3D imaging is a valid tool to recognize and adjust suboptimal reduction or implant positioning. Intraoperative 3D imaging can improve the quality of osteosynthesis especially in fractures of joints and complex anatomical areas.

[Handling modern imaging procedures in a high-tech operating room]

Operating rooms are the central unit in the hospital network in trauma centers. In this area, high costs but also high revenues are generated. Modern operating theater concepts as an integrated model have been offered by different companies since the early 2000s. Our hypothesis is that integrative concepts for operating rooms, in addition to improved operating room ergonomics, have the potential for measurable time and cost savings. In our clinic, an integrated operating room concept (I-Suite, Stryker, Duisburg) was implemented after analysis of the problems. In addition to the ceiling-mounted arrangement, the system includes an endoscopy unit, a navigation system, and a voice control system. In the first 6 months (9/2005 to 2/2006), 112 procedures were performed in the integrated operating room: 34 total knee arthroplasties, 12 endoscopic spine surgeries, and 66 inpatient arthroscopic procedures (28 shoulder and 38 knee reconstructions). The analysis showed a daily saving of 22-45 min, corresponding to 15-30% of the daily changeover times, calculated to account for potential savings in the internal cost allocation of 225-450 EUR. A commercial operating room concept was evaluated in a pilot phase in terms of hard data, including time and cost factors. Besides the described effects further savings might be achieved through the effective use of voice control and the benefit of the sterile handle on the navigation camera, since waiting times for an additional nurse are minimized. The time of the procedure of intraoperative imaging is also reduced due to the ceiling-mounted concept, as the C-arm can be moved freely in the operating theater without hindering cables. By these measures and ensuing improved efficiency, the initial high costs for the implementation of the system may be cushioned over time.

Intraoperative three-dimensional imaging in selective decompression for lumbar spinal stenosis: a useful tool in theory but also in everyday practice?

Background. We conducted a pilot study to investigate the value of an Iso-C3D imaging system in determining the extent of decompression of lumbar spinal stenosis during surgery. We now address the question whether this imaging has become a routine tool. Material and Methods. Ten patients who underwent unilateral decompression for lumbar spinal stenosis were intraoperatively examined using the Iso-C3D imaging system. Four years after this study, we investigated whether this intraoperative imaging modality is still being used. Results. Evaluable images were intraoperatively obtained for all patients. In two cases, the surgical procedure was changed on the basis of the images. Myelography did not provide any additional information. In the four years following the study, this intraoperative imaging technique has not been used again. Conclusion. Intraoperative imaging using the Iso-C3D system provides additional safety. It, however, has not become established as a routine procedure.

Fracture surgery of the extremities with the intra-operative use of 3D-RX: a randomized multicenter trial (EF3X-trial)

BACKGROUND

Posttraumatic osteoarthritis can develop after an intra-articular extremity fracture, leading to pain and loss of function. According to international guidelines, anatomical reduction and fixation are the basis for an optimal functional result. In order to achieve this during fracture surgery, an optimal view on the position of the bone fragments and fixation material is a necessity. The currently used 2D-fluoroscopy does not provide sufficient insight, in particular in cases with complex anatomy or subtle injury, and even an 18-26% suboptimal fracture reduction is reported for the ankle and foot. More intra-operative information is therefore needed.Recently the 3D-RX-system was developed, which provides conventional 2D-fluoroscopic images as well as a 3D-reconstruction of bony structures. This modality provides more information, which consequently leads to extra corrections in 18-30% of the fracture operations. However, the effect of the extra corrections on the quality of the anatomical fracture reduction and fixation as well as on patient relevant outcomes has never been investigated.The objective of this study protocol is to investigate the effectiveness of the intra-operative use of the 3D-RX-system as compared to the conventional 2D-fluoroscopy in patients with traumatic intra-articular fractures of the wrist, ankle and calcaneus. The effectiveness will be assessed in two different areas: 1) the quality of fracture reduction and fixation, based on the current golden standard, Computed Tomography. 2) The patient-relevant outcomes like functional outcome range of motion and pain. In addition, the diagnostic accuracy of the 3D-RX-scan will be determined in a clinical setting and a cost-effectiveness as well as a cost-utility analysis will be performed.

METHODS/DESIGN

In this protocol for an international multicenter randomized clinical trial, adult patients (age > 17 years) with a traumatic intra-articular fracture of the wrist, ankle or calcaneus eligible for surgery will be subjected to additional intra-operative 3D-RX. In half of the patients the surgeon will be blinded to these results, in the other half the surgeon may use the 3D-RX results to further optimize fracture reduction. In both randomization groups a CT-scan will be performed postoperatively. Based on these CT-scans the quality of fracture reduction and fixation will be determined. During the follow-up visits after hospital discharge at 6 and 12 weeks and 1 year postoperatively the patient relevant outcomes will be determined by joint specific, health economic and quality of life questionnaires. In addition a follow up study will be performed to determine the patient relevant outcomes and prevalence of posttraumatic osteoarthritis at 2 and 5 years postoperatively.

DISCUSSION

The results of the study will provide more information on the effectiveness of the intra-operative use of 3D-imaging during surgical treatment of intra-articular fractures of the wrist, ankle and calcaneus. A randomized design in which patients will be allocated to a treatment arm during surgery will be used because of its high methodological quality and the ability to detect incongruences in the reduction and/or fixation that occur intra-operatively in the blinded arm of the 3D-RX. An alternative, pragmatic design could be to randomize before the start of the surgery, then two surgical strategies would be compared. This resembles clinical practice better, but introduces more bias and does not allow the assessment of incongruences that would have been detected by 3D-RX in the blinded arm.

TRIAL REGISTRATION

Dutch Trial Register NTR 1902.

3D-based navigation in posterior stabilisations of the cervical and thoracic spine: problems and benefits. Results of 451 screws

INTRODUCTION

Navigated procedures in spinal surgery have been established due to an increasing demand for precision. Especially, 3D C-arms connected to navigation systems are being used more often and can be utilised intraoperatively for the planning and controlling of screw positions. This prospective study analyses our experiences with 3D-based navigation in posterior stabilisations in the cervical and thoracic spine.

METHODS

A 3D C-Arm (Ziehm Vision Vario 3D(®)) was connected to a navigation system (VectorVision, Brainlab(®)) and used for the placement of, in total, 451 screws among 67 patients. Of those, 14 patients had to undergo operations in the cervical and 53 in the thoracic spine. Postoperatively, the positioning was observed with computed tomography (CT).

RESULTS

The application time is approximately 6 min. In total, 354/451 (78.5%) screws could be inserted assisted with navigation, and 272/451 (60.3%) were controlled intraoperatively. Regarding the cervical spine, in 87.1% (61/70) of the screws, the navigation procedure was uneventful. The positioning of 63.2% (43/68) of the screws was checked intraoperatively. In the upper thoracic spine, 77% (293/381) could be placed with navigation and 59.6% (227/381) were controlled intraoperatively. Occasionally, the scanning setup was problematic. Correct placement was seen in 92.7% of screws; for the remaining screws, no revision was needed.

CONCLUSIONS

Intraoperative 3D imaging navigation for posterior spinal stabilisations is technically feasible and reliable in clinical use. The image quality depends on the individual bone density. With undisturbed visibility of the vertebral body, the reliability of 3D-based navigation is comparable to that of CT-based procedures. Additionally, it has the advantage of skipping the preoperative acquisition of data as well as the matching process, with reduced radiation doses.

[Comparison of early total care (ETC) and damage control orthopedics (DCO) in the treatment of multiple trauma with femoral shaft fractures: benefit and costs]

INTRODUCTION

Femoral fractures are common injuries in multiple trauma patients. The treatment concept of damage control orthopedics (DCO) is in competition with the concept of early total care (ETC).

PATIENTS AND METHODS

In a retrospective study (2003-2007) 73 multiple trauma patients with femoral shaft fractures were included. The cohort was subdivided according to the Injury Severity Score (ISS) (16-24, 25-39 and more than 40) and treatment strategy (ETC versus DCO). Patients were analyzed for outcome and cost aspects.

RESULTS

In the patient group with an ISS 16-24 ventilation time and intensive care treatment were longer after DCO treatment, overall costs and deficient cost cover were higher in the DCO group. In the patient group with an ISS 25-39 cost aspects showed a higher cover deficient in the DCO group.

CONCLUSION

From an economic point of view the cost deficits for the ETC group were lower than in the DCO group. The treatment strategy should be selected by the pattern of injuries. The costs should be addressed by the Institute for the Hospital Remuneration System (INEK).

First experiences with the use of intraoperative 3D-RX for wrist surgery

With the use of conventional C-arm fluoroscopy for hand surgery, suboptimal positioning of implants, K-wires, insufficient reconstructions and joint incongruities frequently remain unrevealed We prospectively compared the performance of the surgeon interpreted from conventional methods (2D fluoroscopy and direct visual and physical inspection) versus 3D imaging as well as the occurrence of revision surgeries based on post-op radiological findings. Twenty-four intraoperative findings based on 2D fluoroscopy and findings on direct visual and physical inspections were compared with intraoperatively acquired 3D-RX scans by means of a questionnaire. Moreover, record was kept of revision surgery (minimal three months follow up) for all patients treated with the aid of 3D-RX. A clear difference in findings was observed between the performance based on fluoroscopy and direct visual and physical inspection and that based on intraoperative 3D-RX for hand surgery (p < 0.05). Post-operative radiological examinations revealed that none of the 56 patients treated with the aid of 3D-RX needed revision surgery. Intraoperative 3D-RX provides information for the hand surgeon that is additional to the information acquired with conventional fluoroscopy. Intraoperative 3D-RX provides well defined images of the positioning of osteosynthesis material, of the spatial orientation of carpals, and of reconstruction of the wrist joint.

[Medical doctors driving technological innovation: questions about and innovation management approaches to incentive structures for lead users]

Management science defines user-generated innovations as open innovation and lead user innovation. The medical technology industry finds user-generated innovations profitable and even indispensable. Innovative medical doctors as lead users need medical technology innovations in order to improve patient care. Their motivation to innovate is mostly intrinsic. But innovations may also involve extrinsic motivators such as gain in reputation or monetary incentives. Medical doctors' innovative activities often take place in hospitals and are thus embedded into the hospital's organisational setting. Hospitals find it difficult to gain short-term profits from in-house generated innovations and sometimes hesitate to support them. Strategic investment in medical doctors' innovative activities may be profitable for hospitals in the long run if innovations provide first-mover competitive advantages. Industry co-operations with innovative medical doctors offer chances but also bear potential risks. Innovative ideas generated by expert users may result in even higher complexity of medical devices; this could cause mistakes when applied by less specialised users and thus affect patient safety. Innovations that yield benefits for patients, medical doctors, hospitals and the medical technology industry can be advanced by offering adequate support for knowledge transfer and co-operation models.

Clinical and radiological outcomes after stabilisation of complex intra-articular fractures of the distal radius with the volar 2.4 mm LCP

AIM

The purpose of the present study is to evaluate the results of the treatment of intra-articular fractures with the volar 2.4 mm LCP with regard to loss of reduction, clinical outcome and complications.

PATIENTS

Patients treated with a volar 2.4 mm LCP following a complex intra-articular distal radius fracture were assessed by clinical and radiological examination of both wrists, the Disability of Arm, Shoulder and Hand (DASH) outcome instrument, Martini score and the pain Visual Analogue Scale score. Forty patients (40 fractures: 5 type C1, 11 type C2, and 24 type C3 according to AO/OTA classification) were followed at a mean 18 months from the injury.

RESULTS

Of the initial 40 fractures, 4 fractures required surgical revision (1 because of loss of reduction, 2 due to fracture incongruity as seen on the postoperative computer tomogram and 1 case of screw displacement in the radial shaft). Radiographs in the immediate postoperative period showed a radial inclination of 22.1 degrees, volar tilt of 7.2 degrees, and ulnar deviation of 0.2 mm (means). At follow-up examination, radial inclination was 23.8 degrees, volar tilt was 6.2 degrees and ulnar deviation was 0.9 mm (means). Average final wrist range of motion was significantly (p < 0.05) decreased in comparison to contralateral wrist. Average DASH and Martini scores were 18 and 27, respectively, with no significant differences between C1-, C2- and C3-type fractures. Patients who underwent a surgical revision had poorer Martini score. Complications were an EPL tendon rupture, a tendon irritation and a complex regional pain syndrome in a patient who underwent revision.

CONCLUSION

The treatment of complex intra-articular distal radius fractures with the volar 2.4 mm LCP provides sufficient fixation to prevent clinically significant loss of articular reduction, acceptable patient outcomes and minimal soft tissue complications.

Utility of intraoperative three-dimensional imaging at the hip and knee joints with and without navigation

Intraoperative three-dimensional imaging in orthopaedic trauma care has achieved greater importance over the last few years in some specialized hospital centers. For various types of peripheral-extremity trauma, clinical studies have confirmed, on the basis of three-dimensional information, an intraoperative revision rate ranging from 7% to 19%. Three-dimensional C-arm imaging may be used to achieve adequate intraoperative information about the quality of fracture reduction, residual steps, and correct implant placement, and this technique has been described for use in both the hip joint (for acetabular fractures, isolated femoral head [Pipkin-type] fractures, three-dimensional navigated sacroiliac screw or acetabular column screw placements, and, less frequently, for navigated drilling of tumors or osteochondral lesions) and the knee joint (for tibial plateau fractures, complex distal femoral condylar fractures, and navigated targeting of osteochondral lesions in combination with the use of preoperative magnetic resonance imaging scans). Major limitations of this technology include increased intraoperative time requirements, limited image quality compared with that of computed tomographic scans, cost, specific positioning techniques, and the need for radiolucent operating-room tables. Although prospective studies have yet to be conducted, the ways in which the surgeon will benefit from the use of intraoperative three-dimensional imaging are apparent, but indications for combined three-dimensional C-arm navigated procedures at the hip and knee joint are still limited. Future directions may include the use of digital flat-panel detectors and even robotic-controlled C-arm motion.

Improved intra-operative reduction control using a three-dimensional mobile image intensifier - a proximal tibia cadaver study

This study aimed to analyse whether the precision of a three-dimensional mobile image intensifier (ISO-C 3D) differs from conventional two-dimensional fluoroscopy and high resolution CT scan in a fracture model of the proximal tibia. A depression fracture of the medial plateau (AO/OTA 41-B2.3) was created in 12 formalin-fixed, human cadaver knees. The cartilage of the depression could be positioned above (+1mm, +2mm), below (-1mm, -2mm), or in line with the joint surface. Fluoroscopy, computed tomography (CT) scans, and ISO-C 3D scans (four different protocols: 100 images, 66 images, 50 images, and 33 images) were done for each fracture level. Three independent observers assessed each imaging set. The difference between the estimated reduction and the real reduction was used for statistical analysis. Our hypothesis was that no differences in the precision exist between the imaging techniques (p<0.05). The conventional image intensifier group (0.7 mm+/-0.67) showed significantly higher deviations than the CT group (0.3 mm+/-0.43; p<0.001) and significantly higher deviations than all ISO-C 3D groups (0.4-0.5 mm; p<0.001). Of the ISO-C 3D groups, only the scan protocol with the lowest number of images (0.5 mm+/-0.51) showed significantly lower precision than the CT group (p<0.001). It was concluded that the three-dimensional mobile image intensifier showed higher precision in reduction assessment in a fracture model of the tibial plateau compared to fluoroscopy. High resolution CT scans should remain the standard for post-operative assessment of reduction outside the operating theatre.

Does intraoperative fluoroscopic 3D imaging provide extra information for fracture surgery?

Fracture surgery of the extremities using 2D fluoroscopy frequently fails to detect the suboptimal positioning of implants and joint incongruities. The use of intraoperative 3D-rotational X-ray (3D-RX) imaging with a new X-ray device potentially reveals these failures. We compared 50 intraoperative (2D) results of surgery and certainty about the effectiveness of different aspects of fracture reduction as interpreted from conventional (2D) methods versus intraoperative 3D-RX in 42 distal extremity fractures by means of a surgery questionnaire. In addition, we investigated the need for revision surgery based on postoperative radiological findings in 81 patients. After fracture reduction, just before a 3D-RX scan, the surgeon preoperatively assessed the result of surgery. Three months after surgery, the 3D-RX scan was judged by three experienced surgeons independently. Intraoperative 3D-RX showed significantly more information as to screw positioning and rotation of the fracture reduction than the conventional method (p < 0.005). None of the 81 patients in whom 3D-RX was performed needed surgical revision based on postoperative radiological examinations. Intraoperative 3D-RX with this new device scanning offers additional information about extremity fracture reduction as compared to conventional intraoperative 2D imaging, and may reduce the need for revision surgery. The value of 3D-RX on functional outcomes still needs to be assessed.