New generation of superior single plating vs. low-profile dual minifragment plating in diaphyseal clavicle fractures: a biomechanical comparative study.

BACKGROUND: Recently, a new generation of superior clavicle plates was developed featuring the variable-angle locking technology for enhanced screw positioning and a less prominent and optimized plate-to-bone fit design. On the other hand, minifragment plates in dual plating mode have demonstrated promising clinical results. The aim of the current study was to compare the biomechanical competence of single superior plating using the new-generation plate vs. dual plating using low-profile minifragment plates. METHODS: Sixteen paired human cadaveric clavicles were pairwise assigned to 2 groups for instrumentation with either a superior 2.7-mm variable-angle locking compression plate (group 1), or with one 2.5-mm anterior combined with one 2.0-mm superior matrix mandible plate (group 2). An unstable clavicle shaft fracture (AO/OTA 15.2C) was simulated by means of a 5-mm osteotomy gap. Specimens were cyclically tested to failure under craniocaudal cantilever bending, superimposed with bidirectional torsion around the shaft axis, and monitored via motion tracking. RESULTS: Initial construct stiffness was significantly higher in group 2 (9.28 ± 4.40 N/mm) compared to group 1 (3.68 ± 1.08 N/mm), P = .003. The amplitudes of interfragmentary motions in terms of axial and shear displacement, fracture gap opening and torsion, over the course of 12,500 cycles were significantly higher in group 1 compared to group 2, P ≤ .038. Cycles to 2 mm shear displacement were significantly lower in group 1 (22,792 ± 4346) compared to group 2 (27,437 ± 1877), P = .047. CONCLUSION: From a biomechanical perspective, low-profile 2.5/2.0-mm dual plates could be considered as a useful alternative for diaphyseal clavicle fracture fixation, especially in less common unstable fracture configurations.

Knot holding capacity of two different high-strength sutures-a biomechanical analysis.

PURPOSE: The number of seven required throws per knot was previously reported as providing sufficient security against slippage. A novel high-strength suture featuring dynamic tightening may allow for throw number reduction without compromising stability. The aims of this study were to (1) investigate the influence of the throw number and the effect of different ambient conditions on the knot security of two different high-strength sutures, and (2) compare their biomechanical competence. METHODS: Two sutures (FiberWire (FW) and DynaCord (DC)) were considered for preparing alternating surgical knots. The specimens were stratified for exposure to different media during biomechanical testing-namely air (dry), saline solution (wet), and fat (fatty-wet). A monotonic tensile ramp loading to failure was applied in each test run. For each suture and ambient condition, seven specimens with three to seven throws each were tested (n = 7), evaluating their slippage and ultimate force to failure. The minimum number of throws preventing suture unraveling was determined for each suture type and condition. RESULTS: For each suture type and condition, failure occurred via rupture in all specimens for the following minimum number of throws: FW-dry-7, wet-7, fatty-wet-7; DC-dry-6, wet-4, fatty-wet-5. When applying seven throws, FW demonstrated significantly larger slippage (6.5 ± 2.2 mm) versus DC (3.5 ± 0.4 mm) in wet (p = 0.004) but not in dry and fatty-wet conditions (p ≥ 0.313). CONCLUSIONS: The lower number of throws providing knot security of DC versus FW in the more realistic wet and fatty-wet conditions indicates that the novel DC suture may allow to decrease the foreign body volume and save surgical time without compromising the biomechanical competence.

Optimizing Subtalar Arthrodesis: A Human Cadaveric Evaluation of a Novel Partially-Threaded Screw Combination in the Delta Configuration.

Background and Objectives: Despite the established role of subtalar joint arthrodesis (SJA) for treatment of subtalar osteoarthritis, achieving bone union remains challenging, with up to 46% non-union rates. Adequate compression and stable fixation are crucial for successful outcomes, with internal screw fixation being the gold standard for SJA. The delta configuration, featuring highly divergent screws, offers stability, however, it can result in hardware irritation in 20-30% of patients. Solutions to solve this complication include cannulated compression screw (CCS) countersinking or cannulated compression headless screw (CCHS) application. The aim of this biomechanical study was to investigate the stability of a delta configuration for SJA utilizing either a combination of a posterior CCHS and an anterior CCS or a standard two-CCS combination. Materials and Methods: Twelve paired human cadaveric lower legs were assigned pairwise to two groups for SJA using either two CCSs (Group 1) or one posterior CCHS and one anterior CCS (Group 2). All specimens were tested under progressively increasing cyclic loading to failure, with monitoring of the talocalcaneal movements via motion tracking. Results: Initial stiffness did not differ significantly between the groups, p = 0.949. Talocalcaneal movements in terms of varus-valgus deformation and internal-external rotation were significantly bigger in Group 1 versus Group 2, p ≤ 0.026. Number of cycles until reaching 5° varus-valgus deformation was significantly higher in Group 2 versus Group 1, p = 0.029. Conclusions: A delta-configuration SJA utilizing a posterior CCHS and an anterior CCS is biomechanically superior versus a standard configuration with two CCSs. Clinically, the use of a posterior CCHS could prevent protrusion of the hardware in the heel, while an anterior CCS could facilitate less surgical time and thus less complication rates.

Which non-infection related risk factors are associated with impaired proximal femur fracture healing in patients under the age of 70 years?

BACKGROUND/PURPOSE: Impaired healing is a feared complication with devastating outcomes for each patient. Most studies focus on geriatric fracture fixation and assess well known risk factors such as infections. However, risk factors, others than infections, and impaired healing of proximal femur fractures in non-geriatric adults are marginally assessed. Therefore, this study aimed to identify non-infection related risk factors for impaired fracture healing of proximal femur fractures in non-geriatric trauma patients. METHODS: This study included non-geriatric patients (aged 69 years and younger) who were treated between 2013 and 2020 at one academic Level 1 trauma center due to a proximal femur fracture (PFF). Patients were stratified according to AO/OTA classification. Delayed union was defined as failed callus formation on 3 out of 4 cortices after 3 to 6 months. Nonunion was defined as lack of callus-formation after 6 months, material breakage, or requirement of revision surgery. Patient follow up was 12 months. RESULTS: This study included 150 patients. Delayed union was observed in 32 (21.3%) patients and nonunion with subsequent revision surgery occurred in 14 (9.3%). With an increasing fracture classification (31 A1 up to 31 A3 type fractures), there was a significantly higher rate of delayed union. Additionally, open reduction and internal fixation (ORIF) (OR 6.17, (95% CI 1.54 to 24.70, p ≤ 0.01)) and diabetes mellitus type II (DM) (OR 5.74, (95% CI 1.39 to 23.72, p = 0.016)), were independent risk factors for delayed union. The rate of nonunion was independent of fracture morphology, patient's characteristics or comorbidities. CONCLUSION: Increasing fracture complexity, ORIF and diabetes were found to be associated with delayed union of intertrochanteric femur fractures in non-geriatric patients. However, these factors were not associated with the development of nonunion.

Evaluation of Cannulated Compression Headless Screw (CCHS) as an alternative implant in comparison to standard S1-S2 screw fixation of the posterior pelvis ring: a biomechanical study.

BACKGROUND/PURPOSE: Posterior pelvis ring injuries represent typical high-energy trauma injuries in young adults. Joint stabilization with two cannulated sacroiliac (SI) screws at the level of sacral vertebrae S1 and S2 is a well-established procedure. However, high failure- and implant removal (IR) rates have been reported. Especially, the washer recovery can pose the most difficult part of the IR surgery, which is often associated with complications. The aim of this biomechanical study was to evaluate the stability of S1-S2 fixation of the SI joint using three different screw designs. METHODS: Eighteen artificial hemi-pelvises were assigned to three groups (n = 6) for SI joint stabilization through S1 and S2 corridors using either two 7.5 mm cannulated compression headless screws (group CCH), two 7.3 mm partially threaded SI screws (group PT), or two 7.3 mm fully threaded SI screws (group FT). An SI joint dislocation injury type III APC according to the Young and Burgess classification was simulated before implantation. All specimens were biomechanically tested to failure in upright standing position under progressively increasing cyclic loading. Interfragmentary and bone-implant movements were captured via motion tracking and evaluated at four time points between 4000 and 7000 cycles. RESULTS: Combined interfragmentary angular displacement movements in coronal and transverse plane between ilium and sacrum, evaluated over the measured four time points, were significantly bigger in group FT versus both groups CCH and PT, p ≤ 0.047. In addition, angular displacement of the screw axis within the ilium under consideration of both these planes was significantly bigger in group FT versus group PT, p = 0.038. However, no significant differences were observed among the groups for screw tip cutout movements in the sacrum, p = 0.321. Cycles to failure were highest in group PT (9885 ± 1712), followed by group CCH (9820 ± 597), and group FT (7202 ± 1087), being significantly lower in group FT compared to both groups CCH and PT, p ≤ 0.027. CONCLUSION: From a biomechanical perspective, S1-S2 SI joint fixation using two cannulated compression headless screws or two partially threaded SI screws exhibited better interfragmentary stability compared to two fully threaded SI screws. The former can therefore be considered as a valid alternative to standard SI screw fixation in posterior pelvis ring injuries. In addition, partially threaded screw fixation was associated with less bone-implant movements versus fully threaded screw fixation. Further human cadaveric biomechanical studies with larger sample size should be initiated to understand better the potential of cannulated compression headless screw fixation for the therapy of the injured posterior pelvis ring in young trauma patients.

Evaluation of cannulated compression headless screws as an alternative implant for superior pubic ramus fracture fixation: a biomechanical study.

BACKGROUND/PURPOSE: Pubic ramus fractures account for the most common types of pelvic fractures. The standard surgical approach for superior pubic ramus fractures (SPRF) is a minimally invasive percutaneous screw fixation. However, percutaneous closed reduction and internal fixation of anterior pelvic ring injuries have high failure rates of up to 15%. The aim of this biomechanical study was to evaluate the stability of SPRF following stabilization with retrograde placed cannulated compression headless screw (CCHS) versus conventional fully and partially threaded screws in an artificial pelvic bone model. METHODS: SPRF type II as described by Nakatani et al. was created by means of osteotomies in eighteen anatomical composite hemi-pelvises. Specimens were stratified into three groups of six specimens each (n = 6) for fixation with either a 7.3 mm partially threaded cannulated screw (group RST), a 7.3 mm fully threaded cannulated screw (group RSV), or a 7.5 mm partially threaded cannulated CCHS (group CCS). Each hemi-pelvic specimen was tested in an inverted upright standing position under progressively increasing cyclic axial loading. The peak load, starting at 200 N, was monotonically increased at a rate of 0.1 N/cycle until 10 mm actuator displacement. RESULTS: Total and torsional displacement were associated with higher values for RST versus CCS and RSV, with significant differences between RST and CCS for both these parameters (p ≤ 0.033). The differences between RST and RSV were significant for total displacement (p = 0.020), and a trend toward significance for torsional displacement (p = 0.061) was observed. For both failure criteria 2 mm total displacement and 5° torsional displacement, CCS was associated with significantly higher number of cycles compared to RST (p ≤ 0.040). CONCLUSION: CCHS fixation presented predominantly superior stability to the standard surgical treatment and could therefore be a possible alternative implant for retrograde SPRF screw fixation, whereas partially threaded screws in group RST were associated with inferior biomechanical stability.

Is a Washer a Mandatory Component in Young Trauma Patients with S1-S2 Iliosacral Screw Fixation of Posterior Pelvis Ring Injuries? A Biomechanical Study.

Background and purpose: Cannulated screws are standard implants for percutaneous fixa-tion of posterior pelvis ring injuries. The choice of whether to use these screws in combination with a washer is still undecided. The aim of this study was to evaluate the biomechanical competence of S1-S2 sacroiliac (SI) screw fixation with and without using a washer across three different screw designs. Material and Methods: Twenty-four composite pelvises were used and an SI joint injury type APC III according to the Young and Burgess classification was simulated. Fixation of the posterior pelvis ring was performed using either partially threaded short screws, fully threaded short screws, or fully threaded long transsacral screws. Biomechanical testing was performed under progressively increasing cyclic loading until failure, with monitoring of the intersegmental and bone-implant movements via motion tracking. Results: The number of cycles to failure and the corresponding load at failure (N) were significantly higher for the fully threaded short screws with a washer (3972 ± 600/398.6 ± 30.0) versus its counterpart without a washer (2993 ± 527/349.7 ± 26.4), p = 0.026. In contrast, these two parameters did not reveal any significant differences when comparing fixations with and without a washer using either partially threaded short of fully threaded long transsacral screws, p ≥ 0.359. Conclusions: From a biomechanical perspective, a washer could be optional when using partially threaded short or fully threaded long transsacral S1-S2 screws for treatment of posterior pelvis ring injuries in young trauma patients. Yet, the omission of the washer in fully threaded short screws could lead to a significant diminished biomechanical stability.

The Possibilities of Personalized 3D Printed Implants-A Case Series Study.

Background and Objectives: Following the most recent software and 3D printing developments, the use of personalized 3D printed orthopedic implants for treatment of complicated surgical cases has gained more popularity. Today, orthopedic problems that cannot be solved with standard implants may be effectively addressed using personalized prostheses. The aim of this study is to present the designing, modeling and production stages of four different personalized 3D printed prostheses and their application in clinical cases of patients who underwent treatment in various anatomical locations with a precisely specified indication for implantation. Materials and Methods: Based on computed tomography scanning, personalized 3D printed prostheses were designed, produced and used in four patients within a period of three to five days after injury or admission. Results: Early term follow-ups demonstrated good to excellent results. Conclusions: Personalized 3D printed prostheses offer an opportunity for a treatment of choice and provide good anatomical and functional results, shortened surgical time, less complications, and high satisfaction in patients with appropriate indications. The method should be considered primarily for patients with large bone defects, or such indicated for resection. Personalized 3D printed prostheses have the potential to become more common and beneficial in the future.

Antegrade Posterior Column Acetabulum Fracture Screw Fixation via Posterior Approach: A Biomechanical Comparative Study.

Background and Objectives: Minimally invasive surgeries for acetabulum fracture fixation are gaining popularity due to their known advantages versus open reduction and internal fixation. Antegrade or retrograde screw fixation along the long axis of the posterior column of the acetabulum is increasingly applied in surgical practice. While there is sufficient justification in the literature for the application of the anterior approach, there is a deficit of reports related to the posterior approach. The aim of this study was to evaluate the biomechanical competence of posterior column acetabulum fracture fixation through antegrade screw placement using either a standard cannulated screw or a cannulated compression headless screw (CCHS) via posterior approach. Materials and Methods: Eight composite pelvises were used, and a posterior column acetabulum fracture according to the Letournel Classification was simulated on both their left and right sides via an osteotomy. The sixteen hemi-pelvic specimens were assigned to two groups (n = 8) for either posterior column standard screw (group PCSS) or posterior column CCHS (group PCCH) fixation. Biomechanical testing was performed by applying steadily increased cyclic load until failure. Interfragmentary movements were investigated by means of motion tracking. Results: Initial stiffness demonstrated significantly higher values in PCCH (163.1 ± 14.9 N/mm) versus PCSS (133.1 ± 27.5 N/mm), p = 0.024. Similarly, cycles and load at failure were significantly higher in PCCH (7176.7 ± 2057.0 and 917.7 ± 205.7 N) versus PCSS (3661.8 ± 1664.5 and 566.2 ± 166.5 N), p = 0.002. Conclusion: From a biomechanical perspective, CCHS fixation demonstrates superior stability and could be a valuable alternative option to the standard cannulated screw fixation of posterior column acetabulum fractures, thus increasing the confidence in postoperative full weight bearing for both the patient and treating surgeon. Whether uneventful immediate postoperative full weight bearing can be achieved with CCHS fixation should primarily be investigated in further human cadaveric studies with a larger sample size.

A Novel Implant for Superior Pubic Ramus Fracture Fixation-Development and a Biomechanical Feasibility Study.

Background and Objectives: Pubic ramus fractures are common in compound pelvic injuries known to have an increased rate of morbidity and mortality along with recurrent and chronic pain, impeding a patient's quality of life. The current standard treatment of these fractures is percutaneous screw fixation due to its reduced risk of blood loss and shorter surgery times. However, this is an intricate surgical technique associated with high failure rates of up to 15%, related to implant failure and loss of reduction. Therefore, the aim of this biomechanical feasibility study was to develop and test a novel intramedullary splinting implant for fixation of superior pubic ramus fractures (SPRF), and to evaluate its biomechanical viability in comparison with established fixation methods using conventional partially or fully threaded cannulated screws. Materials and Methods: A type II superior pubic ramus fracture according to the Nakatani classification was created in 18 composite hemi-pelvises via a vertical osteotomy with an additional osteotomy in the inferior pubic ramus to isolate the testing of three SPRF fixation techniques performed in 6 semi-pelvises each using either (1) a novel ramus intramedullary splint, (2) a partially threaded ramus screw, or (3) a fully threaded ramus screw. Results: No significant differences were detected among the fixation techniques in terms of initial construct stiffness and number of cycles to failure, p ≥ 0.213. Conclusion: The novel ramus intramedullary splint can be used as an alternative option for treatment of pubic ramus fractures and has the potential to decrease the rate of implant failures due to its minimally invasive implantation procedure.

Trochanteric fracture pattern is associated with increased risk for nonunion independent of open or closed reduction technique.

PURPOSE: Soft tissue injury and soft tissue injury as risk factors for nonunion following trochanteric femur fractures (TFF) are marginally investigated. The aim of this study was to identify risk factors for impaired fracture healing in geriatric trauma patients with TFF following surgical treatment with a femoral nail. METHODS: This retrospective cohort study included geriatric trauma patients (aged > 70 years) with TFF who were treated with femoral nailing. Fractures were classified according to AO/OTA. Nonunion was defined as lack of callus-formation after 6 months, material breakage, and requirement of revision surgery. Risk factors for nonunion included variables of clinical interest (injury pattern, demographics, comorbidities), as well as type of approach (open versus closed) and were assessed with uni- and multivariate regression analyses. RESULTS: This study included 225 geriatric trauma patients. Nonunion was significantly more frequently following AO/OTA 31A3 fractures (N = 10, 23.3%) compared with AO/OTA type 31A2 (N = 6, 6.9%) or AO/OTA 31A1 (N = 3, 3.2%, p < 0.001). Type 31A3 fractures had an increased risk for nonunion compared with type 31A1 (OR 10.3 95%CI 2.2 to 48.9, p = 0.003). Open reduction was not associated with increased risk for nonunion (OR 0.9, 95%CI 0.1 to 6.1. p = 0.942) as was not the use of cerclage (OR 1.0, 95%CI 0.2 to 6.5, p = 0.995). Factors such as osteoporosis, polytrauma or diabetes were not associated with delayed union or nonunion. CONCLUSION: The fracture morphology of TFF is an independent risk factor for nonunion in geriatric patients. The reduction technique is not associated with increased risk for nonunion, despite increased soft tissue damage following open reduction.

A Novel Technique for Treatment of Metaphyseal Voids in Proximal Humerus Fractures in Elderly Patients.

Background and Objectives: The treatment of proximal humerus fractures in elderly patients is challenging, with reported high complication rates mostly related to implant failure involving screw cut-out and penetration. Metaphyseal defects are common in osteoporotic bone and weaken the osteosynthesis construct. A novel technique for augmentation with polymethylmethacrylate (PMMA) bone cement was developed for the treatment of patients in advanced age with complex proximal humerus fractures and metaphyseal voids, whereby the cement was allowed to partially cure for 5-7 min after mixing to achieve medium viscosity, and then it was manually placed into the defect through the traumatic lateral window with a volume of 4-6 mL per patient. The aim of this retrospective clinical study was to assess this technique versus autologous bone graft augmentation and no augmentation. Materials and Methods: The outcomes of 120 patients with plated Neer three- and four-part fractures, assigned to groups of 63 cases with no augmentation, 28 with bone graft augmentation and 29 with cement augmentation, were assessed in this study. DASH, CS, pain scores and range of motion were analyzed at 3, 6 and 12 months. Statistical analysis was performed with factors for treatment and age groups, Neer fracture types and follow-up periods, and with the consideration of age as a covariate. Results: DASH and CS improved following cement augmentation at three and six months compared to bone grafting, being significant when correcting for age as a covariate (p ≤ 0.007). While the age group had a significant effect on both these scores with worsened values at a higher age for non-augmented and grafted patients (p ≤ 0.044), this was not the case for cement augmented patients (p ≥ 0.128). Cement augmentation demonstrated good clinical results at 12 months with a mean DASH of 10.21 and mean CS percentage of 84.83% versus the contralateral side, not being significantly different among the techniques (p ≥ 0.372), despite the cement augmented group representing the older population with more four-part fractures. There were no concerning adverse events specifically related to the novel technique. Conclusions: This study has detailed a novel technique for the treatment of metaphyseal defects with PMMA cement augmentation in elderly patients with complex proximal humerus fractures and follow-up to one year, whereby the cement was allowed to partially cure to achieve medium viscosity, and then it was manually placed into the defect through the traumatic lateral window. The results demonstrate clinically equivalent short-term results to 6 months compared to augmentation with bone graft or no augmentation-despite the patient group being older and with a higher rate of more severe fracture patterns. The technique appears to be safe with no specifically related adverse events and can be added in the surgeon's armamentarium for the treatment of these difficult to manage fractures.

The impact of SARS-CoV-2 (COVID-19) pandemic on trauma bay management and guideline adherence in a European level-one-trauma centre.

PURPOSE: SARS CoV-2 (COVID-19) represents a pandemic that has led to adjustments of routine clinical practices. The initial management in the trauma bay follows detailed international valid algorithms. This study aims to work out potential adjustments of trauma bay algorithms during a global pandemic in order to reduce contamination and to increase safety for patients and medical personnel. METHODS: This retrospective cohort study compared patients admitted to the trauma bay of one academic level-one trauma centre in March and April 2019 with patients admitted in March and April 2020. Based on these datasets, possible adjustments of the current international guidelines of trauma bay management were discussed. RESULTS: Group Pan (2020, n = 30) included two-thirds the number of patients compared with Group Ref (2019, n = 44). The number of severely injured patients comparable amongst these groups: mean injury severity score (ISS) was significantly lower in Group Pan (10.5 ± 4.4 points) compared with Group Ref (15.3 ± 9.2 points, p = 0.035). Duration from admission to whole-body CT was significantly higher in Group Pan (23.8 ± 9.4 min) compared with Group Ref (17.3 ± 10.7 min, p = 0.046). Number of trauma bay admissions decreased, as did the injury severity for patients admitted in March and April 2020. In order to contain spreading of SARS Cov-2, the suggested recommendations of adjusting trauma bay protocols for severely injured patients include (1) minimizing trauma bay team members with direct contact to the patient; (2) reducing repeated examination as much as possible, with rationalized use of protective equipment; and (3) preventing potential secondary inflammatory insults. CONCLUSION: Appropriate adjustments of trauma bay protocols during pandemics should improve safety for both patients and medical personnel while guaranteeing the optimal treatment quality. The above-mentioned proposals have the potential to improve safety during trauma bay management in a time of a global pandemic.

Is augmented femoral lateral plating with helically shaped medial plates biomechanically advantageous over straight medial plates?

Dual plating of comminuted distal femoral fractures allows for early patient mobilization. An additional helically shaped medial plate avoids the medial vital structures of the thigh. The aim of this study is to investigate the biomechanical competence of an augmented lateral locking compression plate distal femur (LCP-DF) using an additional straight versus a helically shaped medial LCP of the same length. Ten pairs of human cadaveric femora were instrumented with a lateral anatomical 15-hole LCP-DF. Following, they were pairwise instrumented with either an additional medial straight 14-hole LCP (group 1) or a 90°-helical shape LCP (group 2). All specimens were biomechanically tested under quasi-static and progressively increasing combined cyclic axial and torsional loading until failure. Initial interfragmentary axial displacement and flexion under static compression were significantly smaller in group 1 (0.11 ± 0.12 mm and 0.21 ± 0.10°) versus group 2 (0.31 ± 0.14 mm and 0.68 ± 0.16°), p ≤ 0.007. Initial varus deformation under static compression remained not significantly different between group 1 (0.57 ± 0.23°) and group 2 (0.75 ± 0.34°), p = 0.085. Flexion movements during dynamic loading were significantly bigger in group 2 (2.51 ± 0.54°) versus group 1 (1.63 ± 1.28°), p = 0.015; however, no significant differences were observed in terms of varus, internal rotation, and axial and shear displacements between the groups, p ≥ 0.204. Cycles to failure and load at failure were higher in group 2 (25,172 ± 6376 and 3017 ± 638 N) compared to group 1 (22,277 ± 4576 and 2728 ± 458 N) with no significant differences between them, p = 0.195. From a biomechanical perspective, helical double plating may be considered a useful alternative to straight double plating, demonstrating ameliorated damping capacities during flexion deformation and safer application as the medial neurovascular structures of the thigh are avoided.

Antegrade anterior column acetabulum fracture fixation with cannulated compression headless screws-A biomechanical study on standardized osteoporotic artificial bone.

PURPOSE: Due to the increase in life expectancy and high-energy traumas, anterior column acetabular fractures (ACFs) are also increasing. While open reduction and internal fixation (ORIF) is still the standard surgical procedure, minimally invasive, percutaneous fixation of osteoporotic acetabulum fractures (AF) are growing in popularity. The aim of this biomechanical study was to evaluate the biomechanical competence following antegrade fixation with a standard screw versus a cannulated compression headless screw. METHODS: Eight anatomical osteoporotic composite pelvises were given an anterior column fracture. Two groups of eight specimens each (n = 8) for fixation with either a 6.5 mm cannulated compression headless screw in group Anterior Acetabulum Canulated Compression Headless Screw (AACCH), or with a 6.5 mm partially threaded cannulated screw in group Anterior Acetabulum Standard Screw (AASS) where compared. Each specimen was biomechanically loaded cyclically at a rate of 2 Hz with monotonically increasing compressive load until failure. Motions were assessed by means of optical motion tracking. RESULTS: Initial construct stiffness trended higher in group AACCH at 152.4 ± 23.1 N/mm compared to group AASS at 118.5 ± 34.3 N/mm, p = 0.051. Numbers of cycles and corresponding peak load at failure, were significantly higher in group AACCH at 6734 ± 1669 cycles and 873.4 ± 166.9 N versus group AASS at 4440 ± 2063 cycles and 644.0 ± 206.3 N, p = 0.041. Failure modes were breakout of the screws around the proximal entry point. CONCLUSION: From a biomechanical perspective, group AACCH was associated with superior biomechanical competence compared to standard partially threaded cannulated screws and could therefore be considered as valid alternative for fixation of anterior acetabulum fractures.

Clinical validation of the "Straight-Leg-Evaluation-Trauma-Test" (SILENT) as a rapid assessment tool for injuries of the lower extremity in trauma bay patients.

PURPOSE: Clinical assessment of the major trauma patient follows international validated guidelines without standardized trauma-specific assessment of the lower extremities for injuries. This study aimed to validate a novel clinical test for lower extremity evaluation during trauma resuscitation phase. METHODS: This diagnostic, prognostic observational cohort study was performed on trauma patient treated at one level I trauma center between Mar 2022 and Mar 2023. The Straight-Leg-Evaluation-Trauma (SILENT) test follows three steps during the primary survey: inspection for obvious fractures (e.g., open fracture), active elevation of the leg, and cautious elevation of the lower extremity from the heel. SILENT was considered positive when obvious fracture was present and painful or pathological mobility was observed. The SILENT test was compared with standardized radiographs (CT scan or X-ray) as the reference test for fractures. Statistical analysis included sensitivity, specificity, and receiver operating characteristic testing. RESULTS: 403 trauma bay patients were included, mean age 51.6 (SD 21.2) years with 83 fractures of the lower extremity and 27 pelvic/acetabular fractures. Overall sensitivity was 75% (95%CI 64 to 84%), and overall specificity was 99% (95%CI 97 to 100%). Highest sensitivity was for detection of tibia fractures (93%, 95%CI 77 to 99%). Sensitivity of SILENT was higher in the unconscious patient (96%, 95%CI 78 to 100%) with a near 100% specificity. AUC was highest for tibia fractures (0.96, 95%CI 0.92 to 1.0) followed by femur fractures (0.92, 95%CI 0.84 to 0.99). CONCLUSION: The SILENT test is a clinical applicable and feasible rule-out test for relevant injuries of the lower extremity. A negative SILENT test of the femur or the tibia might reduce the requirement of additional radiological imaging. Further large-scale prospective studies might be required to corroborate the beneficial effects of the SILENT test.

Efficacy and outcomes of rescue screws in unstable pelvic ring injuries - A retrospective matched cohort study.

PURPOSE: The emergency treatment of unstable pelvic ring injuries is still a challenge and requires surgical and anesthesiological resuscitation. Emergency fixation of the unstable pelvic ring with percutaneous sacroiliac (SI) screws, also known as "Rescue Screws", is an established treatment method. The aim of our study was to compare the outcome and complication rates of "Rescue Screws" with elective SI-screw fixations. METHODS: A 1:1 ratio nearest-neighbor matched, retrospective cohort study of trauma patients with acute pelvic ring injuries at a level one trauma center was performed. Patients ≥ 15 years, treated with SI-screw fixation were included. EXCLUSION CRITERIA: pathologic fractures, missing consent and navigated procedures. The primary outcome parameters was defined as SI-screw revision operations. Patients were stratified according to treatment strategy (RS: Rescue Screws; EL: elective SI-screws). RESULTS: From 392 patients identified between 11/2014 and 08/2021, 186 met the inclusion criteria with 41 in the RS Group and 145 in the EL group. After matching, 41 patients were included in each group with similar baseline characteristics except persistent hemodynamic shock (RS: n = 22 (53.37%) vs. EL: n = 1 (4.3%), p < 0.001). Surgical characteristics were comparable in terms of instrumentation levels and insertion-sites. No significant differences were observed in the outcome parameters (revisions, reoperations, implant-associated complications, LOS and mortality) between both groups. CONCLUSION: Treatment of unstable pelvic ring fractures with Rescue Screws appears as a feasible treatment option for emergency stabilization. Rescue Screws are not associated with elevated revision rates and increased complications rates. This minimally invasive technique enables safe emergency stabilization of the posterior pelvic ring. Prospective or randomized clinical trials are required to directly compare Rescue Screws with other competing emergency stabilization techniques.

Does the injury pattern drive the surgical treatment strategy in multiply injured patients with major fractures?

BACKGROUND: The timing of definitive surgery in multiple injured patients remains a topic of debate, and multiple concepts have been described. Although these included injury severity as a criterion to decide on the indications for surgery, none of them considered the influence of injury distributions. We analyzed whether injury distribution is associated with certain surgical strategies and related outcomes in a cohort of patients treated according to principles of early and safe fixation strategies. METHODS: In this retrospective cohort study, multiple injured patients were included if they were primarily admitted to a Level I trauma center, had an Injury Severity Score of ≥16 points, and required surgical intervention for major injuries and fractures. The primary outcome measure was treatment strategy. The treatment strategy was classified according to the timing of definitive surgery after injury: early total care (ETC, <24 hours), safe definitive surgery (SDS, <48 hours), and damage control (DC, >48 hours). Statistics included univariate and multivariate analyses of mortality and the association of injury distributions and surgical tactics. RESULTS: Between January 1, 2016, and December 31, 2022, 1,471 patients were included (mean ± SD age, 55.6 ± 20.4 years; mean Injury Severity Score, 23.1 ± 11.4). The group distribution was as follows: ETC, n = 85 (5.8%); SDS, n = 665 (45.2%); and DC, n = 721 (49.0%); mortality was 22.4% in ETC, 16.1% in SDS, and 39.7% in DC. Severe nonlethal abdominal injuries (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.4-3.5) and spinal injuries (OR, 1.6; 95% CI, 1.2-2.2) were associated with ETC, while multiple extremity injuries were associated with SDS (OR, 1.7; 95% CI, 1.4-2.2). Severe traumatic brain injury was associated with DC (OR, 1.3; 95% CI, 1.1-1.4). When a correction for the severity of head, abdominal, spinal, and extremity injuries, as well as differences in the values of admission pathophysiologic parameters were undertaken, the mortality was 30% lower in the SDS group when compared with the DC group (OR, 0.3; 95% CI, 0.2-0.4). CONCLUSION: Major spinal injuries and certain abdominal injuries, if identified as nonlethal, trigger definitive surgeries in the initial setting. In contrast, severe TBI was associated with delayed fracture care. Patients with major fractures and other injuries were treated by SDS (definitive care, <48 hours) when the pathophysiological response was adequate. The choice of a favorable surgical treatment appears to depend on injury patterns and physiological patient responses. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

3D-navigation for SI screw fixation - How does it affect radiation exposure for patients and medical personnel?

BACKGROUND: 3D-navigation for percutaneous sacroiliac (SI) screw fixation is becoming increasingly common and several studies report great advantages of this technology. However, there is still limited clinical evidence on the efficacy regarding radiation exposure for patient and personnel. METHODS: This is a retrospective, single-center cohort study. All patients who underwent percutaneous sacroiliac screw fixation for an injury of the posterior pelvic ring from 2014 to 2021 were screened. Inclusion criteria were: conclusive radiation dosage reports, signed informed consent, a twelve month follow up and a complete data set. Patients were stratified in two groups (3D-navigation (Group 3D-N) vs. control (Group F)) based on the imaging modality used. Primary outcomes were radiation exposure for patient and personnel. Secondary outcomes were reoperations, complications, and intraoperative precision. RESULTS: Of 392 patients screened, 174 patients (3D-N: n = 50, F: n = 124) could be included for final analysis. We noted a significant reduction of the dose corresponding to potential radiation exposure for medical personnel (-15.3 mGy, 95 %CI: -2.1 to -28.5, p = 0.0232), but also a significant increase of the dose quantifying radiation exposure for patients (+77.0 mGy, 95 %CI: +53.3 to +100.6, p < 0.0001), when using navigation. In addition, the rate of radiographic malplacement was significantly reduced (F: 11.3% vs. 3D-N: 0 %, p = 0.0113) despite a substantial increase in transsacral screw placement (F: 19.4% vs. 3D-N: 76 %). CONCLUSION: Our data clearly suggests that the use of 3D-navigation for percutaneous SI screw fixation decreases radiation exposure for medical personnel, while increasing radiation exposure for patients. Furthermore, intraoperative precision is improved, even in more challenging operations.

The value of pre-hospital trauma life support courses for medical personnel-a questionnaire study.

Background: The aim of the study was to determine the impact that PHTLS® course participation had on self-confidence of emergency personnel, regarding the pre-hospital treatment of patients who had suffered severe trauma. Furthermore, the goal was to determine the impact of specific medical profession, work experience and prior course participation had on the benefits of PHTLS® training. Methods: A structured questionnaire study was performed. Healthcare providers from local emergency services involved in pre-hospital care in the metropolitan area of Zurich (Switzerland, Europe) who completed a PHTLS® course were included. Altered self-confidence, communication, and routines in the treatment of severe trauma patients were examined. The impact of prior course participation, work experience and profession on course benefits were evaluated. Results: The response rate was 76%. A total of 6 transport paramedics (TPs), 66 emergency paramedics (EPs) and 15 emergency doctors (EDs) were included. Emergency paramedics had significantly more work experience compared with EDs (respectively 7.1 ± 5.7 yrs. vs. 4.5 ± 2.1 yrs., p = 0.004). 86% of the participants reported increased self-confidence in the pre-hospital management of severe trauma upon PHTLS® training completion. Moreover, according to 84% of respondents, extramural treatment of trauma changed upon course completion. PHTLS® course participants had improved communication in 93% of cases. This was significantly more frequent in EPs than TPs (p = 0.03). Multivariable analysis revealed emergency paramedics benefit the most from PHTLS® course participation. Conclusion: The current study shows that PHTLS® training is associated with improved self-confidence and enhanced communication, with regards to treatment of severe trauma patients in a pre-hospital setting, among medical emergency personnel. Additionally, emergency paramedics who took the PHTLS® course improved in overall self-confidence. These findings imply that all medical personal involved in the pre-hospital care of trauma patients, in a metropolitan area in Europe, do benefit from PHTLS® training. This was independent of the profession, previous working experience or prior alternative course participation.