Comparison of iCT-based navigation and fluoroscopic-guidance for atlantoaxial screw placement in 78 patients with traumatic cervical spine injuries.

BACKGROUND CONTEXT: Studies have shown biomechanical superiority of cervical pedicle screw placement over other techniques. However, accurate placement is challenging due to the inherent risk of neurovascular complications. Navigation technology based on intraoperative 3D imaging allows highly accurate screw placement, yet studies specifically investigating screw placement in patients with traumatic atlantoaxial injuries are scarce. The aim of this study was to compare atlantoaxial screw placement as treatment of traumatic instabilities using iCT-based navigation or fluoroscopic-guidance with intraoperative 3D control scans. METHODS: This was a retrospective review of patients with traumatic atlantoaxial injuries treated operatively with dorsal stabilization of C1 and C2. Patients were either assigned to the intraoperative navigation or fluoroscopic-guidance group. Screw accuracy, procedure time, and revisions were compared. RESULTS: Seventy-eight patients were included in this study with 51 patients in the navigation group and 27 patients in the fluoroscopic-guidance group. In total, 312 screws were placed in C1 and C2. Screw accuracy was high in both groups; however, pedicle perforations > 1 mm occurred significantly more often in the fluoroscopic-guidance group (P = 0.02). Procedure time was on average 23 min shorter in the navigation group (P = 0.02). CONCLUSIONS: This study contributes to the available data showing that navigated atlantoaxial screw placement proves to be feasible as well as highly accurate compared to the fluoroscopic-guidance technique without prolonging the time needed for surgery. When comparing these data with other studies, the application of different classification systems for assessment of screw accuracy should be considered.

Analyzing the reduction quality of the distal radioulnar joint after closed K-wire transfixation in a cadaver model: is supination or neutral position superior?

INTRODUCTION: Distal radioulnar joint (DRUJ) instabilities are challenging and their optimal treatment is controversial. In special cases or when reconstruction of the stabilizing triangular fibrocartilage complex (TFCC) fails, K-wire transfixation can be performed. However, no consensus has been reached regarding the rotational position of the forearm in which this should be done. Therefore, it was investigated whether anatomical reduction would best be achieved by transfixation in neutral position or supination of the forearm. MATERIALS AND METHODS: Twelve cadaveric upper limbs were examined before dissection of the DRUJ stabilizing ligaments and after closed transfixation in both positions by C-arm cone-beam CT. Whether this was first done in neutral position or in supination was randomized. The change in the radioulnar ratio (RR) in percentage points (%points) was analyzed using Student's t-test. RR was used since it is a common and sensitive method to evaluate DRUJ reduction, expressing the ulnar head's position in the sigmoid notch as a length ratio. RESULTS: The analysis showed an increased change in RR in neutral position with 5.4 ± 9.7%points compared to fixation in supination with 0.2 ± 16.1%points, yet this was not statistically significant (p = 0.404). CONCLUSIONS: Neither position leads to a superior reduction in general. However, the result was slightly closer to the anatomical position in supination. Thus, transfixation of the DRUJ should be performed in the position in which reduction could best be achieved and based on these data, that tends to be in supination. Further studies are necessary to validate these findings and to identify influential factors.

SMART RHESINs-Superparamagnetic Magnetite Architecture Made of Phenolic Resin Hollow Spheres Coated with Eu(III) Containing Silica Nanoparticles for Future Quantitative Magnetic Particle Imaging Applications.

Magnetic particle imaging (MPI) is a powerful and rapidly growing tomographic imaging technique that allows for the non-invasive visualization of superparamagnetic nanoparticles (NPs) in living matter. Despite its potential for a wide range of applications, the intrinsic quantitative nature of MPI has not been fully exploited in biological environments. In this study, a novel NP architecture that overcomes this limitation by maintaining a virtually unchanged effective relaxation (Brownian plus Néel) even when immobilized is presented. This superparamagnetic magnetite architecture made of phenolic resin hollow spheres coated with Eu(III) containing silica nanoparticles (SMART RHESINs) was synthesized and studied. Magnetic particle spectroscopy (MPS) measurements confirm their suitability for potential MPI applications. Photobleaching studies show an unexpected photodynamic due to the fluorescence emission peak of the europium ion in combination with the phenol formaldehyde resin (PFR). Cell metabolic activity and proliferation behavior are not affected. Colocalization experiments reveal the distinct accumulation of SMART RHESINs near the Golgi apparatus. Overall, SMART RHESINs show superparamagnetic behavior and special luminescent properties without acute cytotoxicity, making them suitable for bimodal imaging probes for medical use like cancer diagnosis and treatment. SMART RHESINs have the potential to enable quantitative MPS and MPI measurements both in mobile and immobilized environments.

Radiation exposure for pedicle screw placement with three different navigation system and imaging combinations in a sawbone model.

BACKGROUND: Studies have shown that pedicle screw placement using navigation can potentially reduce radiation exposure of surgical personnel compared to conventional methods. Spinal navigation is based on an interaction of a navigation software and 3D imaging. The 3D image data can be acquired using different imaging modalities such as iCT and CBCT. These imaging modalities vary regarding acquisition technique and field of view. The current literature varies greatly in study design, in form of dose registration, as well as navigation systems and imaging modalities analyzed. Therefore, the aim of this study was a standardized comparison of three navigation and imaging system combinations in an experimental setting in an artificial spine model. METHODS: In this experimental study dorsal instrumentation of the thoracolumbar spine was performed using three imaging/navigation system combinations. The system combinations applied were the iCT/Curve, cCBCT/Pulse and oCBCT/StealthStation. Referencing scans were obtained with each imaging modality and served as basis for the respective navigation system. In each group 10 artificial spine models received bilateral dorsal instrumentation from T11-S1. 2 referencing and control scans were acquired with the CBCTs, since their field of view could only depict up to five vertebrae in one scan. The field of view of the iCT enabled the depiction of T11-S1 in one scan. After instrumentation the region of interest was scanned again for evaluation of the screw position, therefore only one referencing and one control scan were obtained. Two dose meters were installed in a spine bed ventral of L1 and S1. The dose measurements in each location and in total were analyzed for each system combination. Time demand regarding screw placement was also assessed for all system combinations. RESULTS: The mean radiation dose in the iCT group measured 1,6 ± 1,1 mGy. In the cCBCT group the mean was 3,6 ± 0,3 mGy and in the oCBCT group 10,3 ± 5,7 mGy were measured. The analysis of variance (ANOVA) showed a significant (p < 0.0001) difference between the three groups. The multiple comparisions by the Kruskall-Wallis test showed no significant difference for the comparison of iCT and cCBCT (p1 = 0,13). Significant differences were found for the direct comparison of iCT and oCBCT (p2 < 0,0001), as well as cCBCT and oCBCT (p3 = 0,02). Statistical analysis showed that significantly (iCT vs. oCBCT p = 0,0434; cCBCT vs. oCBCT p = 0,0083) less time was needed for oCBCT based navigated pedicle screw placement compared to the other system combinations (iCT vs. cCBCT p = 0,871). CONCLUSION: Under standardized conditions oCBCT navigation demanded twice as much radiation as the cCBCT for the same number of scans, while the radiation exposure measured for the iCT and cCBCT for one scan was comparable. Yet, time effort was significantly less for oCBCT based navigation. However, for transferability into clinical practice additional studies should follow evaluating parameters regarding feasibility and clinical outcome under standardized conditions.

Reconstruction of the medial patellofemoral ligament with nonresorbable suture tape normalizes patellar maltracking independent of patella-side fixation technique.

PURPOSE: Patellar maltracking caused by a rupture of the medial patellofemoral ligament (MPFL) can be improved by MPFL reconstruction (MPFL-R) with a tendon graft. Nonresorbable suture tape (FiberTape®, FT) is possibly becoming an option to tendon grafts for MPFL-R. Patella-side fixation of FT can be performed with suture anchors or via soft-tissue fixation. The aim of this study was to investigate patellar tracking considering soft-tissue-based and anchor-based patella-side fixation techniques. METHODS: In eight fresh-frozen human knee joint specimens (m/f 4/4; age 75 ± 10 years), the MPFL was identified, and a rupture was placed near the femoral insertion site. In the study group (SG; 4 knees), soft-tissue fixation of the FT was performed at the medial patellar retinaculum; in the control group (CG; 4 knees), FT was fixed at the patella via suture anchors. For native MPFL (nMPFL), ruptured ("injured") MPFL (iMPFL) and reconstructed MPFL (FT-MPFL-SG, respectively, FT-MPFL-CG) cone beam CT scans were performed in 15°, 30°, and 45° of knee joint flexion. Patellar tracking was assessed using the radiological parameters patellar tilt (PT), congruence angle (CA) and posterior patellar edge-trochlear groove ratio (PTR). RESULTS: All recorded radiological parameters increased, respectively, decreased in the CG and SG from the nMPFL to the iMPFL state. After MPFL-R, all parameters normalized when compared to the intact state (nMPFL), regardless of patella-side fixation technique. All investigated parameters of patellotrochlear alignment were positively, respectively, negatively significantly (p < 0.05) correlated throughout all evaluated conditions (nMPFL, iMPFL, FT-MPFL-SG, FT-MPFL-CG). CONCLUSION: MPFL-R with a nonresorbable suture tape can normalize patellar maltracking in fresh-frozen human knee joint specimens in earlier degrees of knee joint flexion independent of patella-side fixation technique. The investigated parameters of patellotrochlear alignment correlate with each other.

Soft-tissue fixation is not inferior to suture-anchor fixation in reconstruction of the medial patellofemoral ligament using a nonresorbable suture tape.

PURPOSE: Reconstruction of the medial patellofemoral ligament (MPFL-R) with nonresorbable suture tape (FiberTape®, FT) is becoming popular. Patella-side fixation of the FT can be performed with suture anchors or via soft-tissue fixation. The aim of this study was to investigate whether patella-side soft-tissue fixation can achieve equivalent primary stability compared to suture-anchor fixation. METHODS: In ten human, fresh-frozen knee joint specimens (m/f 6/4; age 74 ± 9 a), the MPFL was identified and dissected near the femoral insertion site. In five knee joints, the MPFL-R using FT was performed with soft-tissue fixation at the patella (study group; SG), and in five knee joints, the FT was fixed via suture anchors (control group, CG). All reconstructions were evaluated until load to failure of the patella-side fixation with a displacement rate of 200 mm/min. RESULTS: The mean maximum load to failure in the SG was 395.3 ± 57.9 N. All reconstructions failed by complete tearing off the medial patellar retinaculum from its medial patellar margin, but fixation of the FT remained stable. In the CG, the mean maximum load to failure was 239.4 ± 54.5 N and was significantly different compared to the SG (p = 0.04). All reconstructions failed via pullout of the suture anchors. Stiffness and elongation did not differ between the groups, and no failure of the FT was observed in any of the specimens. CONCLUSION: Primary stability of soft-tissue MPFL-R using FT was superior to suture-anchor fixation. Both fixation techniques provided sufficient primary stability, superior to previously reported native MPFL tensile strengths. MPFL-R with FT could be a possible alternative procedure for MPFL-R, eliminating potential complications due to autologous tendon graft harvesting.

Detection of fibular rotational changes in cone beam CT: experimental study in a specimen model.

BACKGROUND: In syndesmotic injuries, incorrect reduction leads to early arthrosis of the ankle joint. Being able to analyze the reduction result is therefore crucial for obtaining an anatomical reduction. Several studies that assess fibular rotation in the incisura have already been published. The aim of the study was to validate measurement methods that use cone beam computed tomography imaging to detect rotational malpositions of the fibula in a standardized specimen model. METHODS: An artificial Maisonneuve injury was created on 16 pairs of fresh-frozen lower legs. Using a stable instrument, rotational malpositions of 5, 10, and 15° internal and external rotation were generated. For each malposition of the fibula, a cone beam computed tomography scan was performed. Subsequently, the malpositions were measured and statistically evaluated with t-tests using two measuring methods: angle (γ) at 10 mm proximal to the tibial joint line and the angle (δ) at 6 mm distal to the talar joint line. RESULTS: Rotational malpositions of ≥ 10° could be reliably displayed in the 3D images using the measuring method with angle δ. For angle γ significant results could only be displayed for an external rotation malposition of 15°. CONCLUSIONS: Clinically relevant rotational malpositions of the fibula in comparison with an uninjured contralateral side can be reliably detected using intraoperative 3D imaging with a C-arm cone beam computed tomography. This may allow surgeons to achieve better reduction of fibular malpositions in the incisura tibiofibularis.

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

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

First Clinical Experience with a Novel 3D C-Arm-Based System for Navigated Percutaneous Thoracolumbar Pedicle Screw Placement.

Background and Objectives: Navigated pedicle screw placement is becoming increasingly popular, as it has been shown to reduce the rate of screw misplacement. We present our intraoperative workflow and initial experience in terms of safety, efficiency, and clinical feasibility with a novel system for a 3D C-arm cone beam computed-tomography-based navigation of thoracolumbar pedicle screws. Materials and Methods: The first 20 consecutive cases of C-arm cone beam computed-tomography-based percutaneous pedicle screw placement using a novel navigation system were included in this study. Procedural data including screw placement time and patient radiation dose were prospectively collected. Final pedicle screw accuracy was assessed using the Gertzbein-Robbins grading system. Results: In total, 156 screws were placed. The screw accuracy was 94.9%. All the pedicle breaches occurred on the lateral pedicle wall, and none caused clinical complications. On average, a time of 2:42 min was required to place a screw. The mean intraoperative patient radiation exposure was 7.46 mSv. Conclusions: In summary, the investigated combination of C-arm CBCT-based navigation proved to be easy to implement and highly reliable. It facilitates the accurate and efficient percutaneous placement of pedicle screws in the thoracolumbar spine. The careful use of intraoperative imaging maintains the intraoperative radiation exposure to the patient at a moderate level.

Fracture reduction and screw position after 3D-navigated and conventional fluoroscopy-assisted percutaneous management of acetabular fractures: a retrospective comparative study.

BACKGROUND: Navigational techniques in orthopaedic trauma surgery have developed over the last years leaving the question of really improving quality of treatment. Especially in marginal surgical indications, their benefit has to be evident. The aim of this study was to compare reduction and screw position following 3D-navigated and conventional percutaneous screw fixation of acetabular fractures. The study hypothesis postulated that better fracture reduction and better screw position are obtained with 3D navigation. MATERIALS AND METHODS: Preoperative and postoperative CT scans of 37 acetabular fractures treated by percutaneous screw fixation (24 3D-navigated, 13 conventional) were evaluated. Differences in pre- and postoperative fracture gaps and steps were compared in all reconstructions as well as the screw position relative to the joint and the fracture. RESULTS: The differences in fracture gaps and fracture steps with and without 3D navigation were not significantly different. Distance of the screw from the joint line, angle difference between screw and ideal angle relative to the fracture line, length of the possible corridor used and position of the screw thread did not show any significant differences. CONCLUSION: Comparison of 3D-navigated and conventional percutaneous surgery of acetabular fractures on the basis of pre- and postoperative CTs revealed no significant differences in terms of fracture reduction and screw position.

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.

[Reconstruction of a fracture of the posterior acetabular wall with Pipkin fracture and lesion of the sciatic nerve after dorsal hip dislocation]. / Rekonstruktion einer Fraktur der hinteren Acetabulumwand mit Pipkin-Fraktur und Ischiadicusläsion nach dorsaler Hüftluxation.

A 50-year-old male suffered a crash landing while paragliding and sustained a posterior dislocation of the hip with a Pipkin fracture type 4 (fracture of the posterior acetabular wall and Pipkin fracture type 2) and a lesion of the sciatic nerve. After primary treatment in an external hospital, the patient was transferred to this hospital 4 days following the trauma. An operative stabilization of the acetabular fracture and the Pipkin fracture was performed using a trochanter flip osteotomy. Despite a large central defect of the femoral head it was decided to attempt a reconstruction. Following fixation of the Pipkin fragment an autologous bone graft harvested from the intertrochanteric region was used to fill the defect. Subsequently, a collagen matrix was applied onto the filled defect and a perineural adaptation of the sciatic nerve was performed.

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

BACKGROUND: The 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. METHODS: A 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. RESULTS: 34 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. CONCLUSIONS: Despite 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.

Radiographic assessment of overlengthening of the MoPyC radial head prosthesis: a cadaveric study.

INTRODUCTION: The aim of this study was to evaluate a radiographic measurement method for assessment of overlengthening of the MoPyC radial head prosthesis. MATERIALS AND METHODS: Seven cadaver specimens were studied in ten stages: native specimen (1), radial head resection (2), and implantation of the MoPyC radial head prostheses (Bioprofile, Tornier, Montbonnot-Saint-Martin, France) in four increasing length (correct length, overlengthening of 1.5 mm, 3 mm, and 5 mm) with an intact medial collateral ligament (MCL 3-6) and following transection of the MCL (7-10). The radiographic measurement method according to Athwal et al. was evaluated to detect overlengthening. Statistical analysis included calculation of the diagnostic accuracy of the radiographic method. RESULTS: The radiographic measurement method correctly determined the size of the radial head prosthesis within ± 1 mm in 224 of 336 scenarios (67%) and within ± 2 mm in 320 of 336 scenarios (95%). With a threshold value of ≥ 1 mm, the overall diagnostic sensitivity for detecting overlengthening when it was present and was 90% and the specificity was 79%. The sensitivity was higher with increasing size of the prosthesis: in cases with overlengthening of 1.5 mm, the sensitivity was 76%, with an overlengthening of 3 mm, the sensitivity was 95%, and with an overlengthening of 5 mm, the sensitivity was 100%. CONCLUSION: The radiographic measurement method of Athwal et al. can be used to estimate and to diagnose the magnitude overlengthening of the MoPyC radial head prosthesis. However, the sensitivity is limited (76%) in cases with a small amount of overlengthening of 1.5 mm.

Cement augmentation of the proximal humerus internal locking system in elderly patients: a multicenter randomized controlled trial.

INTRODUCTION: Cement augmentation of the proximal humerus internal locking system (PHILOS) screws might reduce complication rates in osteoporotic bones. This study compared the risk of mechanical failure during the first year after PHILOS™ treatment of proximal humerus fractures (PHF) without (control group) and with (augmented group) screw augmentation. Secondary objectives were to report shoulder functions, quality of life (QoL), adverse events (AEs), and reoperation rates. MATERIALS AND METHODS: This multicenter randomized trial enrolled patients aged ≥ 65 years with displaced/unstable PHF from eight European centers. Randomization was performed during surgery through sealed opaque envelopes. Mechanical failures were assessed by two independent reviewers via radiographs, shoulder function by Quick DASH, SPADI, and Constant Murley scores, and QoL by EQ-5D. Follow-ups were planned at postoperative 6 weeks, 3, 6, and 12 months. RESULTS: The preliminary analysis of 6-week radiographs of the first 59 enrolled patients suggested a mechanical failure rate lower than expected and the difference between groups was too small to be detected by the planned sample size of 144. The trial was prematurely terminated after 67 patients had been enrolled: 34 (27 eligible) in the control group and 33 (29 eligible) in the augmented group. Follow-ups were performed as planned. Nine patients had mechanical failures and the failure rates (95% CI) were: augmented group, 16.1% (5.5; 33.7); control group, 14.8% (4.2; 33.7); the relative risk (95% CI) for the augmented group was 1.09 (0.32; 3.65) compared to the control group (p = 1.000). No statistically significant differences in shoulder function, QoL, and AEs were observed between study groups at 1 year. Nine patients (15.8%) underwent a revision. CONCLUSIONS: Due to premature termination, the study was underpowered. A larger study will be necessary to determine if cement augmentation lowers the risk of mechanical failure rate.

Tablets for Image Review and Communication in Daily Routine of Orthopedic Surgeons-An Evaluation Study.

Medical images are essential in modern traumatology and orthopedic surgery. Access to images is often cumbersome due to a limited number of workstations. Moreover, due to the tremendous increase of data, the time to review or to communicate images has also become limited. One approach to overcome these problems is to make use of modern mobile devices, like tablet computers, to facilitate image access and associated workflows. Ten orthopedic surgeons were equipped with an Apple iPad mini 2 and specialized viewing software for medical images. The surgeons were able to send images from a workstation onto the tablets or to search for patient images directly. The software enabled the physicians to share images, annotated key slices, and messages instantly with their colleagues. The surgeons carried the tablets within or in the periphery of the hospital. The participants evaluated the software by means of daily questionnaires. Data was collected for a period of 9 months. Nearly 25 images were viewed in total by the surgeons per day. The tablet viewer was used for accessing approximately 30% of these images. On average, the surgeons were asked 1.7 times per day by a colleague for a second opinion. They used the tablets in approximately 29% of these cases. Furthermore, the mean time for accessing images was significantly lower using mobile software compared to conventional methods. Tablet computers can play a vital role for image access and communication in the daily routine of an orthopedic surgeon. Mobile image access is an important aspect for surgeons, especially in larger facilities, to facilitate and accelerate the clinical workflows.

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.

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.

Temporary Cast Application in Dislocated Ankle Fractures Leads to High Rates of Secondary Loss of Reduction: Does the Lauge-Hansen Injury Type Matter?

BACKGROUND: For the temporary treatment of ankle fracture dislocations (AFDs), previous studies indicate higher rates of secondary loss of reduction (LOR) with splint immobilization, prompting consideration for expanding indications for external fixation (ExFix). However, these studies did not investigate the influence of fracture morphology to further improve patient selection. The aim of this study was to investigate the influence of Lauge-Hansen injury type on the LOR rate in bimalleolar or trimalleolar AFDs for temporary cast vs ExFix immobilization. METHODS: In this retrospective cohort study, patients with isolated AFD cases treated at our institution from 2011 to 2020 were reviewed. Inclusion criteria required radiographs depicting initial dislocation and appropriate reduction after Cast or ExFix immobilization. Exclusion criteria encompassed concomitant injuries, open fractures, conservative management as well as surgery performed within 48 hours or at a different facility. Patients were grouped by temporary treatment (Cast or ExFix). The primary endpoint was LOR prior to definitive surgery across various Lauge-Hansen types. RESULTS: The LOR rate was significantly higher in the cast group (40/152, 26.3%) compared to the ExFix group (5/191, 2.6%; P < .0001). In the cast group, LOR was associated with an increase in time to definitive surgery by a mean of 3 days (P < .002). During cast treatment, LOR was significantly more likely for pronation abduction (P = .001) and supination external rotation injuries (P < .0001), whereas no significant differences were observed for pronation external rotation (P = .006), supination adduction (P > .99), and fractures not classifiable (P > .99). CONCLUSION: In cases of AFDs resulting from supination external rotation or pronation abduction trauma according to the Lauge-Hansen classification, especially in the setting of an additional posterior malleolar fracture, primary application of external fixation should be considered to reduce the risk for secondary loss of reduction. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Comparison of T-POD and SAM Pelvic Sling II and the influence of attachment level in the initial management of unstable pelvic type C injuries - a cadaveric study.

BACKGROUND: Type C pelvic fractures (AO/OTA) are severe injuries that frequently lead to bleeding and hemodynamic instability. Pelvic binders play a crucial role in their initial management. Placement at the correct level in the prehospital setting is challenging. The aim of this study was to compare two pelvic binders regarding their effectiveness in reducing intrapelvic volume and increasing intrapelvic pressure in patients with type C pelvic fractures (AO/OTA) when applied at three different levels. METHODS: Rotationally and vertically unstable pelvic injuries (AO/OTA classification 61-C1.1) were produced in five fresh-frozen human cadaveric specimens. Intrapelvic volume, vesical pressure and compression pressure within the pubic symphysis and the sacroiliac joint were measured when applying a SAM Pelvic Sling II and a T-POD at the level of the greater trochanter as well as levels higher and lower than recommended. RESULTS: Comparison of the two pelvic binders positioned at the recommended level (greater trochanter) showed no significant difference in volume reduction (13.85 ± 31.37 cm3, p = 0.442), however, increase in vesical pressure was significantly higher when using the T-POD (5.80 ± 3.27 cmH2O, p = 0.017). When positioned at the level of the iliac crest, vesical pressure increase and intrapelvic volume reduction were significantly greater with the T-POD (14.00 ± 8.57 cmH2O, p = 0.022 and 10.45 ± 5.45 cm3, p = 0.031 respectively). Application of the SAM Pelvic Sling II below the greater trochanter led to a significantly greater decrease in volume (-32.26 ± 7.52 cm3, p = 0.003) than the T-POD. Comparison of the recommended attachment level with incorrect positioning led to no significant differences for the T-POD, while the SAM Pelvic Sling II achieved a significantly lower volume reduction when placed at the iliac crest (40.15 ± 14.57 cm3, p = 0.012) and a significantly lower increase in vesical pressure when applied below the greater trochanter (3.40 ± 1.52 cmH2O, p = 0.007). CONCLUSION: Direct comparison of the two pelvic binders showed that the T-POD achieved significantly greater results when applied at the recommended level and was less susceptible to incorrect positioning. These outcomes support the preferred use of the T-POD for prehospital emergency pelvic stabilisation.