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.

Software-based method for automated intraoperative planning of Schoettle Point in surgical medial patellofemoral ligament reconstruction: A comparative validation study.

BACKGROUND: The aim of the study was to validate a software-based planning method for the Schoettle Point and to evaluate precision and time efficiency of its live overlay on the intraoperative X-ray. METHODS: A software-based method was compared with surgeons' manual planning in an inter- and intrarater study. Subsequently, K-wire placement was performed with and without an overlay of the planning. The time used and the precision achieved were statistically compared. RESULTS: The average deviation between the surgeons (1.68 mm; 2.26 mm) was greater than the discrepancy between the surgeons and the software-based planning (1.30 mm; 1.38 mm). In the intrarater comparison, software-based planning provided consistent results. Live overlay showed a significantly lower positioning error (0.9 ± 0.5 mm) compared with that without overlay (3.0 ± 1.4 mm, p = 0.000; 3.1 ± 1.4 mm, p = 0.001). Live overlay did not achieve a significant time gain (p = 0.393; p = 0.678). CONCLUSION: The software-based planning and live overlay of the Schoettle Point improves surgical precision without negatively affecting time efficiency.

Improving Medical Photography in a Level 1 Trauma Center by Implementing a Specialized Smartphone-Based App in Comparison to the Usage of Digital Cameras: Prospective Panel Study.

BACKGROUND: Medical photography plays a pivotal role in modern health care, serving multiple purposes ranging from patient care to medical documentation and education. Specifically, it aids in wound management, surgical planning, and medical training. While digital cameras have traditionally been used, smartphones equipped with specialized apps present an intriguing alternative. Smartphones offer several advantages, including increased usability and efficiency and the capability to uphold medicolegal standards more effectively and consistently. OBJECTIVE: This study aims to assess whether implementing a specialized smartphone app could lead to more frequent and efficient use of medical photography. METHODS: We carried out this study as a comprehensive single-center panel investigation at a level 1 trauma center, encompassing various settings including the emergency department, operating theaters, and surgical wards, over a 6-month period from June to November 2020. Using weekly questionnaires, health care providers were asked about their experiences and preferences with using both digital cameras and smartphones equipped with a specialized medical photography app. Parameters such as the frequency of use, time taken for image upload, and general usability were assessed. RESULTS: A total of 65 questionnaires were assessed for digital camera use and 68 for smartphone use. Usage increased significantly by 5.4 (SD 1.9) times per week (95% CI 1.7-9.2; P=.005) when the smartphone was used. The time it took to upload pictures to the clinical picture and archiving system was significantly shorter for the app (mean 1.8, SD 1.2 min) than for the camera (mean 14.9, SD 24.0 h; P<.001). Smartphone usage also outperformed the digital camera in terms of technical failure (4.4% vs 9.7%; P=.04) and for the technical process of archiving (P<.001) pictures to the picture archiving and communication system (PACS) and display images (P<.001) from it. No difference was found in regard to the photographer's intent (P=.31) or reasoning (P=.94) behind the pictures. Additionally, the study highlighted that potential concerns regarding data security and patient confidentiality were also better addressed through the smartphone app, given its encryption capabilities and password protection. CONCLUSIONS: Specialized smartphone apps provide a secure, rapid, and user-friendly platform for medical photography, showing significant advantages over traditional digital cameras. This study supports the notion that these apps not only have the potential to improve patient care, particularly in the realm of wound management, but also offer substantial medicolegal and economic benefits. Future research should focus on additional aspects such as patient comfort and preference, image resolution, and the quality of photographs, as well as seek to corroborate these findings through a larger sample size.

Hook plate fixation of Neer type II distal clavicle fractures results in satisfactory patient-reported outcomes but complications and revisions are high.

BACKGROUND: Surgical treatment of distal clavicle fractures Neer type II is challenging. A gold standard has not yet been established, thus various surgical procedures have been described. The purpose of this study is to report the radiological and clinical outcomes using hook plate fixation in Neer type II distal clavicle fractures. METHODS: We retrospectively reviewed data of 53 patients who underwent hook plate fixation between December 2009 and December 2019 with ≥ 2 years of follow-up. Patients with preexisting pathologies or concomitant injuries of the ipsilateral shoulder were excluded. Pre- and postoperative coracoclavicular distance (CCD), bony union and patient-reported outcomes were collected, including the Constant Score (CS) and Subjective Shoulder Value (SSV). Complications and revisions were recorded. RESULTS: At a mean final follow-up of 6.2 years, mean SSV was 91.0% (range, 20-100) and mean CS was 80.9 points (range, 25-99). The mean preoperative CCD was 19.0 mm (range, 5.7-31.8), the mean postoperative CCD was 8.2 mm (range, 4.4-12.2) and the mean CCD following hardware removal was 9.7 mm (range, 4.7-18.8). The loss of reduction following hardware removal was statistically significant (P = 0.007). Eleven (20.8%) patients had complications, with 5 cases of deep or superficial infection (9.4%), four non-unions (7.5%), one periosteosynthetic fracture, one postoperative seroma, one implant failure and one symptomatic acromioclavicular joint arthritis (all 1.9%). A total of 10 patients (18.9%) underwent revision surgery at a mean of 113 (range, 7-631) days. CONCLUSION: Medium-term patient-reported outcomes for hook plate fixation of Neer type II distal clavicle fractures are satisfactory; however, one in five patients suffers a complication with the majority of them requiring revision surgery.

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.

Comparing Temporary Immobilization Using Cast and External Fixator in Unimalleolar Ankle Fracture Dislocations: A Retrospective Case Series.

Studies have reported a high percentage of ankle fracture dislocations with secondary loss of reduction during primary treatment with a splint or cast. This study aimed to assess the rate of secondary loss of reduction in unimalleolar ankle fracture dislocations treated primarily with a cast or external fixator, identify the potential influence of fracture morphology, and investigate the potential implications. Unimalleolar ankle fracture dislocations with and without posterior malleolar fracture between 2011 and 2020 were included. Patients were categorized into two groups, depending on the method of temporary treatment. Fracture morphology, time to definitive surgery, and soft-tissue complications were compared. Of 102 patients, loss of reduction tended to occur more often in the cast group (17.3%) than in the external fixator group (6.0%). The presence of a posterior malleolar fracture did not have a significant influence on loss of reduction in cast immobilization; however, the fragment proved to be significantly bigger in cases with loss of reduction. No statistically significant differences in soft tissue complications or time to definitive surgery were found. Surgeons should consider the application of interval external fixation in the primary treatment of unimalleolar ankle fracture dislocations with additional posterior malleolar fractures.

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.

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.

Comparison of three imaging and navigation systems regarding accuracy of pedicle screw placement in a sawbone model.

3D-navigated pedicle screw placement is increasingly performed as the accuracy has been shown to be considerably higher compared to fluoroscopy-guidance. While different imaging and navigation devices can be used, there are few studies comparing these under similar conditions. Thus, the objective of this study was to compare the accuracy of two combinations most used in the literature for spinal navigation and a recently approved combination of imaging device and navigation system. With each combination of imaging system and navigation interface, 160 navigated screws were placed percutaneously in spine levels T11-S1 in ten artificial spine models. 470 screws were included in the final evaluation. Two blinded observers classified screw placement according to the Gertzbein Robbins grading system. Grades A and B were considered acceptable and Grades C-E unacceptable. Weighted kappa was used to calculate reliability between the observers. Mean accuracy was 94.9% (149/157) for iCT/Curve, 97.5% (154/158) for C-arm CBCT/Pulse and 89.0% for CBCT/StealthStation (138/155). The differences between the different combinations were not statistically significant except for the comparison of C-arm CBCT/Pulse and CBCT/StealthStation (p = 0.003). Relevant perforations of the medial pedicle wall were only seen in the CBCT group. Weighted interrater reliability was found to be 0.896 for iCT, 0.424 for C-arm CBCT and 0.709 for CBCT. Under quasi-identical conditions, higher screw accuracy was achieved with the combinations iCT/Curve and C-arm CBCT/Pulse compared with CBCT/StealthStation. However, the exact reasons for the difference in accuracy remain unclear. Weighted interrater reliability for Gertzbein Robbins grading was moderate for C-arm CBCT, substantial for CBCT and almost perfect for iCT.

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.

Influence of reduction quality on functional outcome and quality of life in the surgical treatment of tibial plateau fractures: A retrospective cohort study.

BACKGROUND: Despite a substantial improvement in the operative treatment of tibial plateau fractures, the surgical procedure remains controversial and is generally challenging, as patients may develop postoperative arthritis and functional impairment of the knee joint. HYPOTHESIS: In the surgical treatment of tibial plateau fractures the intraoperative reposition quality has the greatest influence on the postoperative outcome, whereby misalignments of≥2mm lead to a worse result. PATIENTS AND METHODS: Forty-one patients with tibial plateau fractures were postoperatively examined. The operative treatment was performed under reduction control using an intraoperative 3D C-arm. The follow-up collective was divided into two groups depending on the intraoperative reduction result. The postoperative results were then evaluated using the following parameters: Lysholm score, Rasmussen score, Tegner score, SF-36 score, range of motion and pain level. RESULTS: Group 1 (articular surface incongruencies<2mm) tended to achieve a better result in all scores than group 2 (articular surface incongruencies≥2mm), in the Lysholm score (p=0.039), in the comparison of the range of motion (p=0.012) and the pain level (p=0.039) this was significant. Group 1 achieved an average of 90.71 points (group 2: 78.74) in the Lysholm score. The average range of motion of the knee joint was 138.93° in group 1 (group 2: 127.78°). The average value of the current pain level in group 1 was 1.14 (group 2: 2.63). DISCUSSION: Both study groups achieved a very good result compared to the available literature. 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. Intraoperative adjustments of the reduction should therefore be performed on joint surface irregularities with a size above 2mm. LEVEL OF EVIDENCE: III; retrospective case control study.

Influence of unstable ankle fracture (type Weber C), osteosynthesis and syndesmotic transfixation on position of fibula in tibiofibular notch: a cadaveric study.

PURPOSE: The aim of the cadaveric study was to determine the effects of an unstable ankle fracture on the position of the fibula in the incisural notch and subsequently to evaluate the alterations resulting from the individual steps of a guideline-based osteosynthesis. METHODS: In a specimen model with 20 uninjured fresh-frozen lower legs with induced unstable fracture of the fibula (type Weber C), a guideline-based osteosynthesis was performed. The distances between the anterior and posterior edges of the tibia and fibula and in the center of the incisural notch, as well as the rotation angle of the fibula, were measured in the acquired 3D image data sets and were compared with the intact condition of the ankle mortise. RESULTS: The dissection of the syndesmosis and osteotomy of the fibula results in an external rotation the fibula by 3.6° (p = 0.000), while the distance between the anterior edge of the tibia and the fibula widens by 1.86 mm (p = 0.000). After osteosynthesis of the fibula and transfixation of the syndesmotic region using a positioning screw, the posterior distance is no longer substantially increased by 0.22 mm (p = 0.103) but also reduced by 0.1 mm (p = 0.104) in the tibiofibular notch. The external rotation of the fibula remains slightly increased by just 0.45° (p = 0.009). CONCLUSION: The results indicate that there is a tendency for over-compression when adjusting the tibiofibular distance and that the fibula in the tibiofibular notch tends to remain slightly rotated externally.

Software-Based Method for Automated Segmentation and Measurement of Wounds on Photographs Using Mask R-CNN: a Validation Study.

In clinical routine, wound documentation is one of the most important contributing factors to treating patients with acute or chronic wounds. The wound documentation process is currently very time-consuming, often examiner-dependent, and therefore imprecise. This study aimed to validate a software-based method for automated segmentation and measurement of wounds on photographic images using the Mask R-CNN (Region-based Convolutional Neural Network). During the validation, five medical experts manually segmented an independent dataset with 35 wound photographs at two different points in time with an interval of 1 month. Simultaneously, the dataset was automatically segmented using the Mask R-CNN. Afterwards, the segmentation results were compared, and intra- and inter-rater analyses performed. In the statistical evaluation, an analysis of variance (ANOVA) was carried out and dice coefficients were calculated. The ANOVA showed no statistically significant differences throughout all raters and the network in the first segmentation round (F = 1.424 and p > 0.228) and the second segmentation round (F = 0.9969 and p > 0.411). The repeated measure analysis demonstrated no statistically significant differences in the segmentation quality of the medical experts over time (F = 6.05 and p > 0.09). However, a certain intra-rater variability was apparent, whereas the Mask R-CNN consistently provided identical segmentations regardless of the point in time. Using the software-based method for segmentation and measurement of wounds on photographs can accelerate the documentation process and improve the consistency of measured values while maintaining quality and precision.

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

BACKGROUND: Intraoperative 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. METHODS: Twenty-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). RESULTS: The 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). CONCLUSIONS: The 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.

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

PURPOSE: Acute 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. METHODS: Acute 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. RESULTS: Seventy-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). CONCLUSION: The 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.

Influence of syndesmotic injuries and posterior malleolar ankle fractures on fibula position in the ankle joint: a cadaveric study.

PURPOSE: The aim of this study was to identify to what extent a dissection of the syndesmosis and an avulsed posterior edge of the tibia can change the tibiofibular diastasis and fibular rotation. METHODS: Three-dimensional scans with a mobile C-arm of 22 cadaver legs were taken of the intact fibula, after dissection of the anterior part of the syndesmosis and the interosseous membrane, osteotomy of the posterior malleolus, and osteosynthesis. The tibiofibular diastasis as well as the angle of fibular rotation was identified in the four steps and the means compared to each other using a t test for paired samples. RESULTS: The distinction between the intact fibula vs. the osteotomy of the posterior tibia was 0.082 ± 0.332 mm for the tibiofibular distance in the incisura tibiofibularis (p 0.261) and 0.046 ± 0.486 degrees for the angle of the fibular rotation (p 0.665). CONCLUSION: Neither the dissection of the syndesmosis nor the osteotomy of the posterior malleolus significantly influenced the position of the fibula in the incisura tibiofibularis in the cadaveric model. However, in the nonweight-bearing situation, a lesion of the syndesmotic complex might not be evident in intraoperative three-dimensional imaging.

A standardised computed tomography measurement method for distal fibular rotation.

PURPOSE: The aim of the study is to identify an ideal location to measure fibular rotation in the ankle joint using axial computed tomography (CT) scans. Another objective was to detect the average fibular rotation in the uninjured ankle joint in a large cohort. METHODS: Standardised axial CT with coronal/sagittal reconstructions was performed in healthy ankle joints. Three investigators performed the measurements. In the axial view, each investigator appointed the ideal location to measure the angle of fibular rotation with the use of reference lines either 4, 6, 8 or 10 mm distal from the talar joint line. Inter- and intraobserver reliability, as well as the intraclass correlation coefficient, were determined. RESULTS: CT scans of one hundred individuals-78 males and 22 females-were analysed. The most common locations for measuring the fibular rotation were in 31% of cases 4 mm and in 51% of cases 6 mm distal the talar joint line. The external rotation of the fibula averaged 8.42° ± 4.86° (range 0°-26°). The intraclass coefficient correlations (ICC) for interrater and intrarater reliability were 0.75. CONCLUSIONS: The results of the study demonstrate a reproducible location to measure the fibular rotation in the ankle joint. The most convenient location to measure fibular rotation with a high reliability was 6 mm distal to the talar joint line.

Evaluation of image quality and assessability of a new flat-panel 3D C-arm compared to mobile and fixed computed tomography in posterior spinal fixation.

BACKGROUND: This study evaluates image quality of a new flat-panel three-dimensional (3D) C-arm to the current generation and to intraoperative and stationary computed tomography (CT) in spinal surgery. METHODS: Three-dimensional-imaging of 44 posterior screws acquired with two generations of 3D C-arms (Arcadis Orbic, AO and Cios Spin, CS, Siemens, Germany) and CT scans (mobile intraoperative CT Airo, iCT, Brainlab, Germany and stationary CT Aquilion 32, sCT, Toshiba, Japan) were performed. Evaluation regarded assessability and measurements of implant position. RESULTS: Assessability score was 0.11 in AO, 0.56 in sCT, 0.91 in iCT and 1.46 in CS (p < 0.0005). AO and CS showed a significant difference in accuracy (p = 0.001) as well as CS and iCT (p < 0.001). Measurements of protrusion over the anterior edge did not show a significant difference (p = 0.341). CONCLUSIONS: Image quality of the new generation of flat-panel 3D C-arms competes with CT imaging and offers significant advantages compared to the former generation.

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.

Minimally invasive surgical treatment of minimally displaced acetabular fractures does not improve pain, mobility or quality of life compared to conservative treatment: a matched-pair analysis of 50 patients.

BACKGROUND: Currently available procedures for the treatment of minimally displaced acetabular fractures include conservative treatment and minimally invasive percutaneous screw fixation. Screw fixation of acetabular fractures allows patients' early full-weight bearing due to improved biomechanic stability. Can the range of motion, pain and mobility and quality of life in patients with acetabular fractures be improved by minimally invasive screw fixation, compared to conservative treatment in the long term? METHODS: Patients treated for a minimally displaced acetabular fracture, either conservatively or by closed reduction percutaneous screw fixation, in the period from 2001 to 2013 were included in this retrospective study. Minimal displacement was considered to be less than 5 mm. As well as the collection and analysis of baseline data, Harris Hip Score, Merle d'Aubigné score and Short Form 12 (SF-12) questionnaire data were recorded in the context of a clinical study. To better account for confounding factors, patients of each group were matched. The matched-pair criteria included age, BMI, Letournel fracture classification and the presence of associated injuries. RESULTS: Twenty-five patients from each group were matched. On the Harris Hip Score, conservatively treated patients obtained 96 points (52-100, SD 17) vs. 89 points (45-100, SD 17, p = 0.624). On the Merle d'Aubigné score, conservatively treated patients obtained 17 points (10-18, SD 2) vs. 17 points (11-18, SD 2, p = 0.342). Patients with acetabular fractures treated by minimally invasive screw fixation did not result in improved quality of life, measured by SF-12 questionnaire, compared to conservatively treated patients (PCS 47, SD 9 vs. 44, SD 10; p = 0.294 and MCS 51, SD 7 vs. 53, SD 7; p = 0.795). CONCLUSIONS: The clinical results of the two groups revealed no statistically significant differences. From the data, it cannot be deduced that minimally invasive surgical therapy is superior to conservative treatment of minimally displaced acetabular fractures. Prospective randomised studies are recommended to allow reliable evaluation of both treatment options. TRIAL REGISTRATION: Retrospectively registered.