Intraoperative 3D Imaging Research Articles

Accuracy of Thoracolumbar Pedicle Screw Insertion Based on Routine Use of Intraoperative Imaging and Navigation.

Study DesignRetrospective review.PurposeTo determine the accuracy of thoracolumbar pedicle screw insertion with the routine use of three-dimensional (3D) intraoperative imaging and navigation over a large series of screws in an Asian population.Overview of LiteratureThe use of 3D intraoperative imaging and navigation in spinal surgery is aimed at improving the accuracy of pedicle screw insertion. This study analyzed 2,240 pedicle screws inserted with the routine use of intraoperative navigation. It is one of very few studies done on an Asian population with a large series of screws.MethodsPatients who had undergone thoracolumbar pedicle screws insertion using intraoperative imaging and navigation between 2009 and 2017 were retrospectively analyzed. Computed tomography (CT) images acquired after the insertion of pedicle screws were analyzed for breach of the pedicle wall. The pedicle screw breaches were graded according to the Gertzbein classification. The breach rate and revision rate were subsequently calculated.ResultsA total of 2,240 thoracolumbar pedicle screws inserted under the guidance of intraoperative navigation were analyzed, and the accuracy of the insertion was 97.41%. The overall breach rate was 2.59%, the major breach rate was 0.94%, and the intraoperative screw revision rate was 0.7%. There was no incidence of return to the operating theater for revision of screws.ConclusionsThe routine use of 3D navigation and intraoperative CT imaging resulted in consistently accurate pedicle screw placement. This improved the safety of spinal instrumentation and helped in avoiding revision surgery for malpositioned screws.

3D-imaging in percutaneous spine surgery using the Surgivisio system

The Surgivisio system is a new generation of intraoperative 3D imaging, used in our institution for pedicle insertion in minimally invasive spine surgery since January 2018. The purpose of this technical note is to describe the Surgivisio system, its advantages and its limitations, in percutaneous spinal surgery. Results of the first year of use were analyzed, in a series of 29 patients, to evaluate accuracy of pedicle screw insertion, operative time and radiation exposure. On the Heary and Gertzbein classifications, 95.5% of pedicle screw placements (107/112) were rated as acceptable. Mean operative time was 29.3min per vertebra; mean radiation exposure per vertebra was 0.61 mSv. The Surgivisio system is an effective navigation tool for pedicle screw insertion in minimally invasive spinal surgery, with acceptable radiation exposure and operative time for each navigated vertebra. Level of evidenceII, prospective cohort study.

Noninvasive patient tracker mask for spinal 3D navigation: does the required large-volume 3D scan involve a considerably increased radiation exposure?

Intraoperative 3D imaging and navigation is increasingly used for minimally invasive spine surgery. A novel, noninvasive patient tracker that is adhered as a mask on the skin for 3D navigation necessitates a larger intraoperative 3D image set for appropriate referencing. This enlarged 3D image data set can be acquired by a state-of-the-art 3D C-arm device that is equipped with a large flat-panel detector. However, the presumably associated higher radiation exposure to the patient has essentially not yet been investigated and is therefore the objective of this study. Patients were retrospectively included if a thoracolumbar 3D scan was performed intraoperatively between 2016 and 2019 using a 3D C-arm with a large 30 × 30-cm flat-panel detector (3D scan volume 4096 cm3) or a 3D C-arm with a smaller 20 × 20-cm flat-panel detector (3D scan volume 2097 cm3), and the dose area product was available for the 3D scan. Additionally, the fluoroscopy time and the number of fluoroscopic images per 3D scan, as well as the BMI of the patients, were recorded. The authors compared 62 intraoperative thoracolumbar 3D scans using the 3D C-arm with a large flat-panel detector and 12 3D scans using the 3D C-arm with a small flat-panel detector. Overall, the 3D C-arm with a large flat-panel detector required more fluoroscopic images per scan (mean 389.0 ± 8.4 vs 117.0 ± 4.6, p < 0.0001), leading to a significantly higher dose area product (mean 1028.6 ± 767.9 vs 457.1 ± 118.9 cGy × cm2, p = 0.0044). The novel, noninvasive patient tracker mask facilitates intraoperative 3D navigation while eliminating the need for an additional skin incision with detachment of the autochthonous muscles. However, the use of this patient tracker mask requires a larger intraoperative 3D image data set for accurate registration, resulting in a 2.25 times higher radiation exposure to the patient. The use of the patient tracker mask should thus be based on an individual decision, especially taking into considering the radiation exposure and extent of instrumentation.

Radiation exposure of a mobile 3D C-arm with large flat-panel detector for intraoperative imaging and navigation - an experimental study using an anthropomorphic Alderson phantom

BackgroundIntraoperative 3-dimensional (3D) navigation is increasingly being used for pedicle screw placement. For this purpose, dedicated mobile 3D C-arms are capable of providing intraoperative fluoroscopy-based 3D image data sets. Modern 3D C-arms have a large field of view, which suggests a higher radiation exposure. In this experimental study we therefore investigate the radiation exposure of a new mobile 3D C-arm with large flat-panel detector to a previously reported device with regular flat-panel detector on an Alderson phantom.MethodsWe measured the radiation exposure of the Vision RFD 3D (large 30 × 30 cm detector) while creating 3D image sets as well as standard fluoroscopic images of the cervical and lumbar spine using an Alderson phantom. The dosemeter readings were then compared with the radiation exposure of the previous model Vision FD Vario 3D (smaller 20 × 20 cm detector), which had been examined identically in advance and published elsewhere.ResultsThe larger 3D C-arm induced lower radiation exposures at all dosemeter sites in cervical 3D scans as well as at the sites of eye lenses and thyroid gland in lumbar 3D scans. At ​​male and especially female gonads in lumbar 3D scans, however, the larger 3D C-arm showed higher radiation exposures compared with the smaller 3D C-arm. In lumbar fluoroscopic images, the dosemeters near/in the radiation field measured a higher radiation exposure using the larger 3D C-arm.ConclusionsThe larger 3D C-arm offers the possibility to reduce radiation exposures for specific applications despite its larger flat-panel detector with a larger field of view. However, due to the considerably higher radiation exposure of the larger 3D C-arm during lumbar 3D scans, the smaller 3D C-arm is to be recommended for short-distance instrumentations (mono- and bilevel) from a radiation protection point of view. The larger 3D C-arm with its enlarged 3D image set might be used for long instrumentations of the lumbar spine. From a radiation protection perspective, the use of the respective 3D C-arm should be based on the presented data and the respective application.

Evaluation of Software-Based Metal Artifact Reduction in Intraoperative 3D Imaging of the Spine Using a Mobile Cone Beam CT.

The aim of our study was to evaluate whether software-based artifact reduction can achieve an improved image quality, using intraoperative 3D imaging in spinal surgery. A total of 49 intraoperative 3D image datasets of patients, who underwent surgery with pedicle screw placement, were retrospectively evaluated. The visibility of anatomical structures and the diameter of the pedicle screws were examined, with and without the application of the artifact reduction software. All software prototypes can improve the visibility of anatomical structures (P < 0.01), except MAR (metal artifact reduction) combined with IRIS (iterative reconstruction in image space) (P = 0.04). The algorithms MAR and MAR-2 can reduce the blooming artifacts significantly (P < 0.01), but SL (Shepp & Logan) cannot (P = 0.08-0.988). In summary, software-based artifact reduction for intraoperative 3D datasets can improve the current image quality. Additional information regarding the implant placement and the fracture reduction is therefore generated for the surgeon.

Role of Plain Radiographs in Assessing Appropriate Placement of Orbital Implants for Repair of Floor Fractures.

Intraoperative imaging is becoming increasingly common in repair of facial fractures. Many institutions do not have access to intraoperative advanced 3D imaging but have the capability of obtaining plain radiographs intraoperatively. At institutions where advanced 3D imaging is available, scout radiographs are usually obtained prior to a complete scan. These scout images can provide some information about the placement of radiopaque implants before a complete scan is performed. The aim of this study is to examine the correct anatomic positioning of an orbital floor implant using lateral plain radiographs. Titanium orbital fan implants were molded and secured to orbital floor of 14 adult dry skulls (7 males and 7 females). Lateral radiographs were obtained for both the left and the right orbits individually. The antero-posterior angle of inclination that the implant makes relative to the Frankfort horizontal plane was measured, and results were compared in the male versus female radiographs. The mean angle that the implant made with the Frankfort horizontal plane was 20.1±2.4° in the male orbits (95% CI 18.8-21.5°) and 22.6 ± 2.0° in the female orbits (95% CI, 21.4-23.7°). We found no statistically significant differences between the male and female angles (P-value 0.62). For the combined specimens (i.e., 28 sides in 14 skulls), the overall mean angle was 21.4 ± 2.5° (95% CI, 20.4-22.3°). Based on these findings, the angle that the implant makes with the Frankfort horizontal plane on lateral cross-table plain radiographs can be used intraoperatively to assist the surgeon in confirming the appropriate placement of the implant.

Diagnostic accuracy of intraoperative CT-imaging in complex articular fractures \u2013 a cadaveric study

Anatomic reconstruction of articular fractures is one of the critical factors in later achieving good functional outcome. Intraoperative 3D imaging has been shown to offer better evaluation and therefore can significantly improve the results. The purpose of this study was to assess the difference between intraoperative three-dimensional fluoroscopy (3D) and intraoperative computed tomography (iCT) imaging regarding fracture reduction, implant placement and articular impressions in a distal humeral fracture model. AO type 13-B2 fracture pattern were created in upper extremity cadaver specimens. Articular step-offs, intra-articular screw placement and intraarticular impressions of different degrees of severity were created. All specimens had imaging performed. For each articular pattern 3D fluoroscopy in standard (3Ds) and high quality (3Dh) were performed (Arcadis Orbic, Siemens, Germany) as well as an intraoperative CT scan (iCT, Airo, Brainlab, Germany). Three observers evaluated all imaging studies regarding subjective and objective parameters. iCT is more precise than 3D fluoroscopic imaging for detection of articular impressions. Articular step-offs and intraarticular screw placement are similar for iCT and 3D. Subjective imaging quality is the highest for iCT and lowest for 3Ds. Intraoperative CT may be particularly useful in assessing articular impressions and providing a good subjective image quality for the surgeon.

Validation of radiological reduction criteria with intraoperative cone beam CT in unstable syndesmotic injuries

PurposeAcute unstable syndesmotic lesions are regularly treated with closed or open reduction and fixation with either a positioning screw or tight rope. Conventional fluoroscopy is limited to identify a malreduction of the ankle mortise. The aim of the study was to validate the reduction criteria of intraoperative cone beam CT in unstable syndesmotic injuries by analyzing the clinical outcome.MethodsAcute unstable syndesmotic injuries were treated with a positioning screw fixation, and the reduction in the ankle mortise was evaluated with intraoperative cone beam CT. The patients were grouped postoperatively according to the radiological reduction criteria in the intraoperative 3D images. The reduction criteria were unknown to the surgeons. Malreduction was assumed if one or more reduction criteria were not fulfilled.ResultsSeventy-three of the 127 patients could be included in the study (follow-up rate 57.5%). For 41 patients (56.2%), a radiological optimal reduction was achieved (Group 1), and in 32 patients (43.8%) a radiological adverse reduction was found (Group 2). Group 1 scored significantly higher in the Olerud/Molander score (92.44 ± 10.73 vs. 65.47 ± 28.77) (p = 0.003), revealed a significantly higher range of motion (ROM) (53.44 vs. 24.17°) (p = 0.001) and a significantly reduced Kellgren/Lawrence osteoarthritis score (1.24 vs. 1.79) (p = 0.029). The linear regression analysis revealed a correlation for the two groups with the values scored in the Olerud/Molander score (p < 0.01).ConclusionThe reduction criteria in intraoperative cone beam CT applied to unstable syndesmotic injuries could be validated. Patients with an anatomic reduced acute unstable syndesmotic injury according to the criteria have a significantly better clinical outcome.

First experiences with intraoperative CT in navigated sacroiliac (SI) instrumentation: An analysis of 25 cases and comparison with conventional intraoperative 2D and 3D imaging

BackgroundIntraoperative imaging is regularly used for intraoperative reduction control and evaluation of the implant position in trauma surgery. 2D imaging is limited, especially in complex anatomical regions such as the pelvis. The introduction of mobile 3D C-arms (CBCT: cone-beam computed tomography) has significantly improved intraoperative assessment. Nevertheless, there are still limitations regarding the field of view and metal artifacts. The purpose of this study was to evaluate the potential of intraoperative computed tomography (iCT) in surgical treatment of sacroiliac (SI) injuries. MethodsTwenty-five cases with injuries of the posterior pelvic ring involving the SI region that were surgically treated with navigated SI screws using the mobile iCT Airo (Brainlab, Munich, Germany) were analysed. Subsequently, the data were compared with historical control groups (CBCT with and without navigation; 2D fluoroscopy only). ResultsThe average score for subjective image quality achieved using the Likert scale is significantly higher for the iCT (4.48 ± 0.65) than for the CBCT (3.04 ± 0.69) with p = 0.00. The average duration of surgery using iCT was 189.32 ± 88.64 min, which was not significantly different from the control groups (p = 0.14 - 0.70). The average fluoroscopy time using iCT was 81.96 ± 97.34 s, which was significantly shorter than in all of the control groups (p = 0.00 - 0.03).The rate for postoperatively detected complications after using iCT was 0% (n = 0). Compared with the 2D-only control group (25%; n = 1), there is a significant difference (p = 0.01). The remaining two control groups showed no significant differences (p = 0.09 - 0.19). ConclusionsThe iCT provides excellent image quality that allows reliable assessment of fracture reduction and implant placement even in complex anatomical regions. The radiation exposure for the medical staff is reduced by decreasing the fluoroscopy time without significantly prolonging the surgical time. Overall, the possibility of intraoperative correction improves clinical outcome and patient treatment in the long term.

Augmented reality navigation with intraoperative 3D imaging vs fluoroscopy-assisted free-hand surgery for spine fixation surgery: a matched-control study comparing accuracy

This study aimed to compare screw placement accuracy and clinical aspects between Augmented Reality Surgical Navigation (ARSN) and free-hand (FH) technique. Twenty patients underwent spine surgery with screw placement using ARSN and were matched retrospectively to a cohort of 20 FH technique cases for comparison. All ARSN and FH cases were performed by the same surgeon. Matching was based on clinical diagnosis and similar proportions of screws placed in the thoracic and lumbosacral vertebrae in both groups. Accuracy of screw placement was assessed on postoperative scans according to the Gertzbein scale and grades 0 and 1 were considered accurate. Procedure time, blood loss and length of hospital stay, were collected as secondary endpoints. A total of 262 and 288 screws were assessed in the ARSN and FH groups, respectively. The share of clinically accurate screws was significantly higher in the ARSN vs FH group (93.9% vs 89.6%, p < 0.05). The proportion of screws placed without a cortical breach was twice as high in the ARSN group compared to the FH group (63.4% vs 30.6%, p < 0.0001). No statistical difference was observed for the secondary endpoints between both groups. This matched-control study demonstrated that ARSN provided higher screw placement accuracy compared to free-hand.

Influence of reduction quality on functional outcome and quality of life in treatment of tibial plafond fractures: a retrospective cohort study

BackgroundThe aim of the study was to evaluate the impact of reduction quality, using intraoperative 3D imaging, on quality of life and functional outcome in the operative treatment of tibial plafond fractures.MethodsA group of patients with tibial plafond fractures was re-examined. The operative treatment was performed between September 2001 and October 2011. The follow-up examination was at least 2 years after the final surgical procedure. Final reduction result was assessed intraoperatively using a mobile 3D C-arm. A categorization with regard to descriptive parameters as well as type and size of joint surface irregularities was performed. Follow-up results were evaluated using: Olerud and Molander (O & M) score, Short-Form-36 (SF-36) score, movement deficit, Kellgren and Lawrence grade of osteoarthritis, and pain intensity.Results34 patients with operatively treated tibial plafond fracture could be re-examined. Reduction quality had the greatest influence on functional result measured by the O & M score (p = 0.001) and the PCS domain of the SF-36 score (p = 0.018).Significant differences with regard to O & M score (p = 0.000), SF-36 score (p = 0.001 to p = 0.02; without MCS domain), movement deficit (p = 0.001), grade of osteoarthritis (p = 0.005) and pain (p = 0.001) could be verified under consideration of the reduction quality. The group with the anatomically more accurate reduction also showed a better result for clinical follow-up and quality of life. Furthermore, it is not the type of joint surface irregularity that is always decisive, but rather the size.ConclusionsDespite other relevant factors, it appears that reduction quality –which can be analyzed with intraoperative 3D imaging– plays the most important role in postoperative quality of life and functional outcome. Corrections should therefore be performed on joint surface irregularities with a size above 2 mm.

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.

Intra-Operative 3-Dimensional Imaging (O-arm) in Foot and Ankle Trauma Surgery: Report of 2 Cases and Review of the Literature

Background: Intraoperative two-dimensional (2D) fluoroscopy is the standard imaging modality available to orthopaedic surgeons worldwide. It is well-accepted, however, multiplanar 3 dimensional (3D) CT scanning is superior to 2D imaging for visualising joint surfaces and is now a fundamental feature of the pre-operative planning of intra-articular fractures. Objective: We present two cases in which the use of 3D intraoperative imaging and the O-arm® (Medtronic, Minneapolis, USA) led to immediate intraoperative revision to optimise fixation and articular congruity. A review of the current literature is also provided. Methods: During the trial period of the O-arm at our major trauma centre, intra-operative imaging was used in the lower limb trauma setting. The O-arm was used intra-operatively in a comminuted pilon fracture and a displaced talus fracture. We recorded all the intra-operative events, including quality of reduction, implant positioning and operation time. Each patient was followed-up for 12 months post-operation and was finally assessed with x-rays and the AOFAS score. Results: In both the cases, either fracture reduction or the implant position/usage that was observed with 2D fluoroscopy was revised following a 3D intra-operative scan. No postoperative complications were noted and the healing process was uneventful. X-rays at the final follow-up were excellent and acceptable for the talus and pilon fracture, respectively, with corresponding clinical results and AOFAS score. Conclusion: Although frequently used in spinal surgery, to the best of our knowledge, the use of intra-operative 3D techniques in lower limb trauma is sparse and sporadically reported. We present our cases in which the most current innovative imaging techniques influenced intra-operative outcomes without compromising patient safety. We feel that this is a real example of how innovation can positively influence patient care.

Changes in the Operative Corridor in Oblique Lumbar Interbody Fusion Between Preoperative Imaging and Intraoperative Cone-Beam Computed Tomography Using Morphometric Analysis

Abstract INTRODUCTION Oblique lumbar interbody fusion (OLIF) is a minimally-invasive technique that relies on a sufficient corridor anterior to the psoas and posterior to vascular structures.This intraoperative corridor is evaluated on preoperative computed tomography (CT) and/or magnetic resonance (MR) imaging to guide patient selection.Previous cadaveric studies and preoperative MR imaging analysis have examined this corridor to determine corridor variations along right- and left-sided approaches and among patient characteristics.This is the first study that directly evaluates the true intraoperative corridor in the lateral decubitus position based on intraoperative 3D imaging. METHODS We performed a retrospective evaluation identifying patients &gt; 18 yr old who had undergone an OLIF via a left-sided approach at 2 tertiary care centers from 2016 to 2018. Patients with scoliosis greater than 20 degrees, transitional anatomy, and psoas abnormalities were excluded.We recorded demographics and the intraoperative corridor defined by the distance between the left lateral border of the aorta or iliac vessels and anteromedial border of the psoas from L1-L2 through L4-5 disc spaces.This corridor was measured on supine, preoperative MR axial imaging and subsequent intraoperative 3D cone beam CT acquired in the right lateral decubitus position. RESULTS A total of 33 patients, 15 of whom were female, were included in this study.The average age was 65.4 and body mass index (BMI) was 31 kg/m2.There was a statistically significant increase (P &lt; .05) in the intraoperative corridor from supine to lateral decubitus positioning at all levels.The greatest increase in corridor size was noted at L1-2 (3.1 cm) and least at L4-5 (2.1 cm).There was no statistically significant difference between age, BMI, or gender in the preoperative versus intraoperative corridor. CONCLUSION This is the first study to provide objective evidence to support that lateral decubitus positioning increases the intraoperative corridor for anterior to the psoas techniques.This information should increase confidence with an anterior to the psoas approach if there is adequate corridor size on supine preoperative imaging evaluation.

Intraoperative 3D imaging leads to substantial revision rate in management of tibial plateau fractures in 559 cases

IntroductionThe aim of this study was to evaluate the intraoperative revision rate and reasons for revision following 3D imaging in the management of dislocated articular tibial plateau fractures based on a large patient sample.MethodsThis retrospective cohort study included all patients who underwent open reduction and internal fixation due type B or C tibial plateau fracture according to the AO/OTA classification between August 2001 and December 2017 using intraoperative cone beam CT (3D imaging) for the analysis of fracture reduction and implant placement.The findings of the 3D scan were categorized regarding the amount and type of revision. Furthermore, demographic data was examined.ResultsFive hundred and fifty-nine consecutive fractures were included in the study. Evaluation of the image data records revealed an intraoperative revision due to the usage of 3D imaging in 148 out of 559 cases (26.5%). The most common reasons for an intraoperative revision were insufficient fracture reduction (114 cases) and screw length (21 cases).ConclusionThis study reveals indications for a limited analysis of fracture reduction and implant placement during the operative treatment of dislocated articular tibial plateau fractures using conventional fluoroscopy. In view of the high revision rate during open reduction and internal fixation of tibial plateau fractures due to 3D imaging the usage of intraoperative cone beam, CT may be considered. If this is not possible, a postoperative computed tomography may therefore be reasonable.

The image-guided operating room-Utility and impact on surgeon's performance in the head and neck surgery.

The image-guided operating room (OR) is an emerging standard for dealing with complex cases in many surgical disciplines including neurosurgery, thoracic surgery, maxillofacial trauma, and orthopedic surgery. Its use in head and neck oncological surgery is not well established. The primary aim of this study was to assess the image quality of cone-beam CT (CBCT) under real clinical conditions. The secondary aim was to assess the effect on surgical performance and decision making. Intraoperative 3D imaging was performed using a CBCT capable C-Arm mounted on a multi-axis robot (Siemens Zeego) in the image-guided OR. All patients had immediate preoperative imaging taken with further intraoperative imaging performed as required. Ten initial patients, comprising 28 intraoperative scans, were used for questionnaire-based image reviews conducted with experienced head and neck clinicians. Scans were assessed for aspects of both image quality and clinical utility, on separate 5-point Likert scales (1-5). The median rating for bony detail was 4 out of 5. Vascular detail was increased (P < 10-8 ) from 1 to 3 with the use of IV contrast (region of interest CT# was 284 HU [SD, 47 HU]). Images were rated as 4 for freedom from artifact. Soft tissue definition was 2, with no significant improvement (P = .2) with the addition of IV iodinated contrast. Surgeons rated the greatest clinical utility (4) for the CBCT when assessing postreconstruction imaging of a complex case. The image quality of CBCT in the image-guided OR is good for bony detail and complex oncological reconstructions in the head and neck setting but probably has limited benefit for intraoperative soft tissue delineation. Future studies must also focus on clinical outcomes to help demonstrate the value of the image-guided OR.

The role of anatomic pelvic dissection in the successful closure of bladder exstrophy: an aid to success

Classic bladder exstrophy is one of the rarest congenital anomalies compatible with life. Surgical treatment of bladder exstrophy has progressed, but the goal of surgery remains a successful primary bladder closure. Several factors have been identified to decrease the risk of failed closure, including appropriate use of osteotomyand adequate postoperative immobilization and analgesia. However, the role of the radical anatomic pelvic dissection, including dissection of the urogenital diaphragm fibers, in a successful closure has not yet been extensively explored. The objective of this study was go examine the role of radical anatomic pelvic dissection, including dissection of the urogenital diaphragm fibers, in patients with classic bladder exstrophy. This was a retrospective study based on an institutional database. A retrospective review from an institutional approved database of more than 1,300 patients with epispadias-exstrophy complex was performed. The inclusion criteria included patients with classic bladder exstrophy with at least one failed bladder closure and a reclosure at the authors' institution with a single senior surgeon. Data collection included demographics, clinical variables, and status of urogenital diaphragm fibers. Magnetic resonance imaging (MRI) scans, if available, were reviewed with a pediatric radiologist to identify urogenital diaphragm fibers. From the database, 93 patients met inclusion criteria. Of these patients, 74 had urogenital diaphragm fibers completely intact at the time of repeat closure, whereas 19 patients did not. There was no association with age or gender and status of urogenital diaphragm fibers. There was no association with osteotomy, the type of primary bladder closure, surgeon subspecialty, and the status of the urogenital fibers. Fourteen patients had at least two prior closures; surprisingly, 11 of these repeat closure patients still had intact urogenital fibers even after two prior closures. The recent development and application of 3D MRI-guided pelvic dissection in a large group of patients led the authors to investigate whether adequate pelvic floor dissection had been accomplished at primary or secondary closure. Several patients had MRI scans performed before repeat closure in which the urogenital diaphragm fibers were identified to be intact on imaging; this was corroborated with surgical findings. Approximately 80% of patients had their urogenital diaphragm fibers completely intact and, therefore, did not have an adequate pelvic dissection during their primary or secondary bladder closure, putting the success of their previous closures at risk. Inadequate pelvic diaphragm dissection, defined as intact urogenital diaphragm fibers, demonstrated in a large group of patients with failed exstrophy closure, may be a decisive factor in bladder closure failure. The use of 3D intra-operative image guidance may aid in a safer and more successful pelvic dissection.

Real-time intraoperative 3D image intensifier-based navigation in reversed shoulder arthroplasty- analyses of image quality

BackgroundDue to the high anatomical variability and limited visualization of the scapula, optimal screw placement for baseplate anchorage in reversed total shoulder arthroplasty (rTSA) is challenging. Image quality plays a key role regarding the decision of an appropriate implant position. However, these data a currently missing for rTSA and were investigated in the present study. Furthermore, the rate of required K-wire changes for the central peg as well as post-implantation inclination and version were assessed.MethodsIn ten consecutive patients (8 female, 86 years, range 74–94) with proximal humeral fracture and indication for rTSA, an intraoperative 3D-scan of the shoulder with a 3D image intensifier (Ziehm Vision FD Vario 3D© [Ziehm Imaging GmbH, Nürnberg, Germany]) was performed after resection of the humeral head. Using the Vectorvision© Software (Brainlab AG, Feldkirchen, Germany), the virtual anatomy was compared to the visible anatomical landmarks. After implantation of the baseplate, a 3D scan was performed. All 3D scans included multiplanar reconstruction (MPR) and the cinemode to examine screw and baseplate placement. The rate of required K-wire changes was assessed. The intraoperative 3D image quality (modified visual analogue scale [VAS] and point system) was assessed before and after implantation of the glenoid component. Inclination and version were determined in post-implantation scans.ResultsThe virtually presented anatomical landmarks always correlated to the anatomical visible points indicating an good virtual accuracy. The central K-wire position was corrected in three cases due to a deviation from the face plane technique position. The VAS was higher for the pre-implantation MPR (6.7, range 5–8) compared to the post-implantation acquired MPR (5.1, range 4–6; p = 0.0002). The point system showed a reduced quality in all subcategories, especially regarding the grading of the articular surfaces. The preoperative (7.9, range 6–9) and post-implantation (7.9, range 6–9) cinemode displayed no significant differences (p = 0.6).ConclusionThe present study underlines the need for the improvement of 3D image intensifiers algorithms to reduce artifact associated impaired image quality to enhance the benefit of real-time intraoperative 3D scans and navigation.

Minimal invasive posterior correction of Lenke 5C idiopathic scoliosis: comparative analysis of minimal invasive vs. open surgery

IntroductionSurgical management of adolescent idiopathic scoliosis in spite of usually favourable outcomes is still a major operation. Therefore, efforts are being undertaken to minimalize the procedure, reduce the surgical trauma and postoperative convalescence. The study was designed to compare posterior minimal invasive surgery using navigation based on intraoperative 3D imaging and standard open instrumented fusion in Lenke 5C idiopathic scoliosis treatment.Materials and methodsFrom eight patients with Lenke 5C curves planned for posterior correction and instrumented fusion, four were treated with minimally invasive and four had open procedure. Operation length, estimated blood loss, number of fusion levels, days of opioid intake, length of hospital stay and radiation doses required were noted. Radiographic assessment of spinal curvatures was performed (magnitude, flexibility, sagittal alignment). The comparison of the data was done between open and minimally invasive treated patients.ResultsIn minimally invasive surgery group, the operations were longer on average 285 min ± 47.5 than in the open surgery group, 242.5 min ± 44.5 (p = 0.371) and resulted in slightly inferior coronal curve correction by 68.25% ± 6.2 vs. 78.25% ± 8.8, respectively (p = 0.072). We observed a clear reduction of intraoperative blood loss in minimally invasive patients (mean 138.75 ± 50 vs. 450 ± 106 ml, p = 0.016), shorter hospital stay, average 3.75 vs. 7 days (p = 0.043) and lower opioid requirements postoperatively − 2 vs. 3.25 days (p = 0.015).ConclusionsThe minimally invasive approach to idiopathic scoliosis treatment is a very promising technique to limit the extent of surgery maintaining the same goals as in the open method. It allows for lower blood loss, less requirement for opioids and a shorter hospital stay.

First experiences with the Airo mobile intraoperative CT scanner in acetabular surgery-An analysis of 10 cases.

Being a proven method in trauma and spine surgery, intraoperative 3D imaging (CBCT) has intrinsic deficits in difficult anatomy and with artifacts because of metal implants. The purpose of this study was to evaluate the use of intraoperative computed tomography (iCT) in acetabular surgery. Ten cases of acetabular fractures that were operated with intraoperative use of the mobile CT scanner Brainlab Airo were analyzed. Data were compared with a historical group of 17 patients. Additional fluoroscopy time was 24.2seconds (6-91), which was significantly lower than in the control group where it was 211.4seconds (77-446; P<0.000). Operation time did not differ significantly (iCT group 196.8min [122-288], control group 240.8min [71-411], P=0.234). iCT provides images of a reliable high quality and assessability. Radiation exposure to the staff is reduced while surgery time is not altered significantly. Quality of intraoperative imaging and thus patient care can substantially improve patient outcome.