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.

Age and "general health"-beside fracture classification-affect the therapeutic decision for geriatric pelvic ring fractures: a German pelvic injury register study.

PURPOSE: Pelvic ring fractures in the elderly gain increasing importance. Nonetheless, data on factors influencing treatment decision in relation to fracture classification, age, and the resulting treatment are still rare. METHODS: Prospectively collected data of the German Pelvic Injury Registry from patients aged over 65 years with a pelvic ring fracture were evaluated retrospectively. Acetabular fractures, as well as type A1 and A3 fractures, were excluded. The variables age, injury pattern, type of treatment, the reason for conservative treatment, and Orthopaedic Trauma Association (OTA)/Tile classification were analyzed. Furthermore, the fracture distribution was examined after dividing patients into six age groups. RESULTS: A total of 1814 patients with a mean age of 80.7 ± 7.6 years, predominantly female (79.0%), were available for evaluation. The majority of patients suffered from isolated pelvic ring fractures (70.1%) and 8.2% were severely injured (ISS > 16). The most common fracture types were type A2 (35.4%), type B2 (38.0%), and type C1 (7.3%). Especially pelvic ring fractures of type A2 (96.9%) and type B2 (83.0%) were treated conservatively (overall 76.9%). Fracture instability according to the OTA/Tile classification increased the probability for an operative treatment (generalized odds ratio [OR] 6.90 [5.62; 8.52]). In contrary, increasing age independent of the fracture pattern decreased this probability (OR 0.47 [0.41-0.53]). With increasing fracture instability, general health conditions were up to 50% of the reasons for conservative treatment. CONCLUSION: The results of the present study underline the importance of the factors age and general health besides fracture classification for therapeutic decision-making in the treatment of pelvic ring fractures in the elderly.

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.

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.

Interobserver and intraobserver agreement of ligamentous injuries on conventional MRI after simple elbow dislocation.

BACKGROUND: The primary objective of this study was to assess the interobserver and intraobserver agreement on ligamentous injuries on conventional magnetic resonance imaging (MRI) in acute simple elbow dislocation. The secondary objectives were to determine the interobserver agreement on the assessment of joint congruity, joint effusion, loose bodies and chondral lesions on conventional MRI. METHODS: Conventional MRIs (1.5 Tesla, elbow specific surface coil) of 30 patients (40.7 years; range 14-72) with simple elbow dislocations were evaluated by four blinded examiners. An analysis of the interobserver agreement of all raters and for several subgroups (radiologists, orthopaedics, experienced, non-experienced) was performed. The examiners assessed the integrity (intact, partial tear, complete tear) of the lateral collateral ligament (LCL), medial collateral ligament (MCL), extensor and flexor tendons, as well as the presence of joint congruity, joint effusion, loose bodies and chondral lesions. Agreement strength, correlation and proportion of exact agreement were determined for interobserver agreement, and intraobserver agreement analyses. RESULTS: Interobserver agreement of all examiners was fair to moderate for collateral ligaments (LCL: 0.441, MCL: 0.275). Exact agreement of all raters was found in 33.3% for the LCL and in 26.7% for the MCL. The both experienced examiners showed highest agreement strength for the LCL (0.619) and the radiologists showed highest agreement strength for the MCL (0.627), the proportion of exact agreement was 60.0% in both categories. A high proportion of exact agreement regarding joint congruity (90%), joint effusion (100%), loose bodies (96.7%) and chondral lesion (80%) was found among the radiologists. The evaluation of the intraobserver agreement revealed slight to substantial agreement (0.227 to 0.718) for the collateral ligaments. CONCLUSIONS: This study shows difficulties in the evaluation of ligaments by conventional MRI technique as demonstrated by a weak inter- and intraobserver agreement. This should be the basis to develop new MRI quality standards with special focus on coronal oblique reconstructions to improve the evaluation of ligament injuries after simple elbow dislocations.

Unstable simple elbow dislocations: medium-term results after non-surgical and surgical treatment.

PURPOSE: Determination of the appropriate treatment of unstable simple elbow dislocations is difficult and a topic of ongoing discussion. The aim of this study was to analyse the outcome and complications after surgery and conservative treatment, with special focus on post-traumatic joint laxity. METHODS: In this retrospective study, 118 consecutive patients with simple elbow dislocations underwent stability testing by fluoroscopy after joint reduction and were assigned to groups 1 (slight), 2 (moderate) or 3 (gross) depending on post-traumatic joint laxity. All patients of group 1 underwent conservative treatment, and of group 3 primary ligament repair. In patients with moderate elbow laxity, the treatment was decided individually. All patients underwent a similar functional rehabilitation programme during treatment. Clinical outcome was determined after an average of 3.4 ± 1.5 years using the Mayo Elbow Performance Score (MEPS), and treatment-associated complications and revisions were recorded. RESULTS: Forty-nine patients (41.5 %) were assigned to group 1, 41 patients (34.7 %) to group 2 and 28 patients (23.7 %) to group 3. In group 2, 22 patients underwent ligament repair, while 19 patients were treated conservatively. On average, an excellent MEPS was achieved in group 1 after conservative treatment (MEPS 95.8 ± 9.0), similar to results after ligament repair of grossly unstable elbows in group 3 (91.6 ± 11.7). Interestingly, in group 2 conservative treatment was associated with a slightly lower MEPS (90.0 vs. 95.7), and significantly fewer patients achieved an excellent MEPS (81.8 vs. 52.6 %, p = 0.045). Similarly, conservative treatment in group 2 was associated with a fivefold to sixfold risk of complications (p = 0.032) and revision surgery (p = 0.023). CONCLUSIONS: This study supports the notion that patients with slight elbow laxity can be treated non-operatively, while primary surgical treatment should be performed in patients with moderate and gross laxity to avoid post-traumatic sequelae and decrease revision rates. LEVEL OF EVIDENCE: Retrospective Cohort Study, Level III.

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.

Development and validation of a novel questionnaire for self-determination of the range of motion of wrist and elbow.

BACKGROUND: The aim of this study was to develop and validate a novel self-administered questionnaire for assessing the patient's own range of motion (ROM) of the wrist and the elbow. METHODS: In a prospective clinical study from January 2015 to June 2015, 101 consecutive patients were evaluated with a novel, self-administered, diagram-based, wrist motion assessment score (W-MAS) and elbow motion assessment score (E-MAS). The questionnaire was statistically evaluated for test-retest reliability, patient-physician agreement, comparison with healthy population, and influence of covariates (age, gender, affected side and involvement in workers' compensation cases). RESULTS: Assessment of patient-physician agreement demonstrated almost perfect agreement (k > 0.80) with regard to six out of eight items. There was substantial agreement with regard to two items: elbow extension (k = 0.76) and pronation (k = 0.75). The assessment of the test-retest reliability revealed at least substantial agreement (k = 0.70). The questionnaire revealed a high discriminative power when comparing the healthy population with the study group (p = 0.007 or lower for every item). Age, gender, affected side and involvement in workers' compensation cases did not in general significantly influence the patient-physician agreement for the questionnaire. CONCLUSION: The W-MAS and E-MAS are valid and reliable self-administered questionnaires that provide a high level of patient-physician agreement for the assessments of wrist and elbow ROM. LEVEL OF EVIDENCE: Diagnostic study, Level II.

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.

Combined Odontoid (C2) and Atlas (C1) Fractures in Geriatric Patients: A Systematic Review and Treatment Recommendation.

STUDY DESIGN: Systematic review. OBJECTIVE: The aim of this study was to conduct a systematic overview of the pathogenesis and the treatment options of combined odontoid and atlas fractures in geriatric patients. METHODS: This review is based on articles retrieved by a systematic search in the PubMed and Web of Science databases for articles published until February 2021 dealing with combination fractures of C1 and C2 in geriatric patients. RESULTS: Altogether, 438 articles were retrieved from the literature search. A total of 430 articles were excluded. The remaining eight original articles were included in this systematic review depicting the topics pathogenesis, non-operative treatment, posterior approach, and anterior approach. The overall level of evidence of the studies is low. CONCLUSION: Combined odontoid and atlas fractures in the geriatric population are commonly caused by simple falls and seem to be associated with atlanto-odontoid osteoarthritis. Non-operative treatment with a cervical orthosis is a feasible treatment option in the majority of patients with stable C2 fractures. In case of surgery posterior C1 and C 2 stabilization and anterior triple or quadruple screw fixation are possible techniques. Some patients may also deserve an occipito-cervical fusion. A possible treatment algorithm is proposed.

Fiducial marker recovery and detection from severely truncated data in navigation-assisted spine surgery.

PURPOSE: Fiducial markers are commonly used in navigation-assisted minimally invasive spine surgery and they help transfer image coordinates into real-world coordinates. In practice, these markers might be located outside the field-of-view (FOV) of C-arm cone-beam computed tomography (CBCT) systems used in intraoperative surgeries, due to the limited detector sizes. As a consequence, reconstructed markers in CBCT volumes suffer from artifacts and have distorted shapes, which sets an obstacle for navigation. METHODS: In this work, we propose two fiducial marker detection methods: direct detection from distorted markers (direct method) and detection after marker recovery (recovery method). For direct detection from distorted markers in reconstructed volumes, an efficient automatic marker detection method using two neural networks and a conventional circle detection algorithm is proposed. For marker recovery, a task-specific data preparation strategy is proposed to recover markers from severely truncated data. Afterwards, a conventional marker detection algorithm is applied for position detection. The networks in both methods are trained based on simulated data. For the direct method, 6800 images and 10 000 images are generated, respectively, to train the U-Net and ResNet50. For the recovery method, the training set includes 1360 images for FBPConvNet and Pix2pixGAN. The simulated data set with 166 markers and four cadaver cases with real fiducials are used for evaluation. RESULTS: The two methods are evaluated on simulated data and real cadaver data. The direct method achieves 100% detection rates within 1 mm detection error on simulated data with normal truncation and simulated data with heavier noise, but only detect 94.6% markers in extremely severe truncation case. The recovery method detects all the markers successfully in three test data sets and around 95% markers are detected within 0.5 mm error. For real cadaver data, both methods achieve 100% marker detection rates with mean registration error below 0.2 mm. CONCLUSIONS: Our experiments demonstrate that the direct method is capable of detecting distorted markers accurately and the recovery method with the task-specific data preparation strategy has high robustness and generalizability on various data sets. The task-specific data preparation is able to reconstruct structures of interest outside the FOV from severely truncated data better than conventional data preparation.

Intraoperative Computed Tomography in Orthopaedic Trauma Surgery. / Intraoperative CT-Bildgebung in der Traumatologie.

BACKGROUND: When using mobile 3D C-arms, impairments in image quality occur due to artefacts caused by metal implants as well as to the limited field of view. To avoid these restrictions, special computed tomography devices were designed, in order to improve image quality and to meet requirements for intraoperative usage. OBJECTIVES: To analyse practicability and benefits of a mobile intraoperative CT device (Airo, Brainlab, Munich, Germany) on the basis of several parameters that were obtained during a 40-month period. MATERIALS AND METHODS: All procedures that were performed with usage of intraoperative CT between January 2017 and April 2020 were analysed with respect to anatomical region, count of scans, duration of scans, consequences drawn from the scans and use of navigation. RESULTS: 354 CT-scans were performed in 171 patients (mean 2.07 [1 - 6] scans per procedure). 47.81% of the procedures were spinal, 52.19% affected the pelvis. 83% of the procedures were navigated. In 22% of patients, improvement in implant placement or reduction was achieved; in most patients (55%), a guidewire for pedicle screws was corrected. The mean scan duration was 10.33 s (3.54 - 21.72). CONCLUSIONS: Use of intraoperative CT was reliable and helpful. Integration in OR standards requires more effort than mobile 3D C-arms. Image quality was outstanding for intraoperative conditions and allowed proper assessment of implant placement and reduction in all cases. Due to the high financial outlay of the system and the good image quality of 3D C-arms in the extremities, we assume that this procedure can be applied in intraoperative CT in traumatological cases in spinal and pelvic surgery in high-level trauma centres.

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.

Optimal timing of extracorporeal shock wave treatment to protect ischemic tissue.

Enhancement of flap survival through extracorporeal shock wave treatment (ESWT) is a promising new technique; however, no attempt has been made to define the optimal time point and frequency of ESWT to optimize treatment with ESWT for ischemic indications. Twenty-eight male Wistar rats were randomized into 4 groups and an oversized, random-pattern flap was raised and reattached in place in each animal. ESWT was applied 7 days before (group E7) or immediately after the surgical intervention (group E0). The third group was treated with ESWT 7 days before and additionally immediately after the operation (group E7/0). The fourth group served as a control group and did not receive any ESWT (group C). Seven days after flap harvest the results of flap survival, perfusion, microvessel density, and vascular endothelial growth factor concentrations were assessed. Flap survival was significantly increased in all ESWT groups as compared with the control group. The groups (E7 and E0) that received ESWT pre- or postoperatively showed a significant increase in flap perfusion and microvessel density. Combined pre- and postoperative ESWT application (group E0/E7) did not demonstrate a cumulative effect in any evaluation. In this study, we were be able to prove the effectiveness of ESWT in the protection of ischemic tissue flaps. This study suggests that single postoperative application is the most efficacious protocol for clinical applications of ESWT in the treatment of ischemic tissue.

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.

Cervical Spine Immobilization in Patients With a Geriatric Facial Structure: The Influence of a Geriatric Mandible Structure on the Immobilization Quality Using a Cervical Collar.

INTRODUCTION: Demographic changes have resulted in an increase in injuries among geriatric patients. For these patients, a rigid cervical collar is crucial for immobilizing the cervical spine. However, evidence suggests that patients with a geriatric facial structure require a different means of immobilization than patients with an adult facial structure. This study aimed to analyze the remaining motion of the immobilized cervical spine based on facial structure. MATERIALS AND METHODS: This study was performed on 8 fresh human cadavers. Facial structure was evaluated via ascertaining the mandibular angle by computer tomography. A mandibular angle below 130°, belongs to the adult facial structure group (n = 4) and a mandibular angle above 130°, belongs to the geriatric facial structure group (n = 4). The flexion and lateral bending of the immobilized cervical spine were analyzed in both groups using a wireless motion tracker system. RESULTS: A flexion of up to 19.0° was measured in the adult facial structure group. The mean flexion in the adult vs. geriatric facial structure groups were 14.5° vs. 6.5° (ranges: 9.0-19.0 vs. 5.0-7.0°), respectively. Thus, cervical spine motion was (p = 0.0286) significantly more reduced in the adult facial structure group. No (p = 0.0571) significant difference was oberserved in the mean lateral bending of the adult facial structure group (14.5°) compared to the geriatric facial structure group (7.5°). CONCLUSION: Emergency medical service personnel should therefore follow current guidelines and recommendations and perform cervical spine immobilization with a cervical collar, including in patients with a geriatric facial structure.

Analysis of remaining motion using one innovative upper airway opening cervical collar and two traditional cervical collars.

The aim of this study was to compare the remaining motion of an immobilized cervical spine using an innovative cervical collar as well as two traditional cervical collars. The study was performed on eight fresh human cadavers. The cervical spine was immobilized with one innovative (Lubo Airway Collar) and two traditional cervical collars (Stifneck and Perfit ACE). The flexion and lateral bending of the cervical spine were measured using a wireless motion tracker (Xsens). With the Weinman Lubo Airway Collar attached, the mean remaining flexion was 20.0 ± 9.0°. The mean remaining flexion was lowest with the Laerdal Stifneck (13.1 ± 6.6°) or Ambu Perfit ACE (10.8 ± 5.8°) applied. Compared to that of the innovative Weinmann Lubo Airway Collar, the remaining cervical spine flexion was significantly decreased with the Ambu Perfit ACE. There was no significant difference in lateral bending between the three examined collars. The most effective immobilization of the cervical spine was achieved when traditional cervical collars were implemented. However, all tested cervical collars showed remaining motion of the cervical spine. Thus, alternative immobilization techniques should be considered.

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.