The Application of a Surgery Supporting Computer System Does Not Seem to Influence the Surgeons' Radiation Exposure: A Retrospective Analysis.

Since 2019, a surgery supporting system (SPM, surgical process manager; Johnson & Johnson, New Brunswick, New Jersey, Vereinigte Staaten) has been used in a Level I trauma center for common trauma surgery procedures (distal radius fractures, proximal femur fractures, ankle fractures, proximal humerus fractures, and spine fractures). The hypothesis of this study was that implementing standardized procedures (by using SPM) may reduce radiation exposure, especially for unexperienced surgeons.Workflows were developed for different surgical procedures (distal radius fractures, proximal femur fractures, ankle fractures, proximal humerus fractures, and spine fractures) and added into the SPM. Between October 2019 and June 2022, 90 surgeries using the SPM were included in the study. A control group was included with 107 surgeries using the same surgical technique. The values measured were the radiation exposure during the surgical procedure, the experience of the head surgeon, and whether or not the SPM was used. A statistical analysis was performed by using the chi square and Fischer exact tests, with significance set at a p value < 0.05.SPM was applicated in 51 cases for the distal radius (control group 54 patients), 20 cases for distal fibula fractures (control group 21 patients), 9 cases for the proximal femur (control group 19 patients), 5 cases for vertebral fractures (control group 7 patients), and 5 cases for the proximal humerus (control group 6 patients). No difference concerning the median radiation exposure was observed by plating distal radius fractures with 5.7 Gy/cm² in the SPM group and a median radiation exposure of 6.4 Gy/cm² in the control group (p = 0.96). The distal fibula fractures showed no significant difference in the intraoperative radiation (17.4 Gy/cm² vs. 6.4 Gy/cm², p value 0.53). Radiation exposure was lower when a consultant performed surgery without showing any significance, independent if SPM was used or not.In this study, no significant difference in the intraoperative radiation dose was observed when using a surgery supporting computer system. The experience of the surgeon showed no influence as well, regardless if SPM was used or not. Additional data should be collected questioning these findings.

3D C-arm navigated suture button implantation for AC joint dislocations - the pilot study.

PURPOSE: The surgical treatment of acute traumatic AC joint dislocations is still a subject of scientific debate in the literature. The arthroscopically assisted stabilization procedure with a suture button system has been successfully established and is widely used in daily practice. It is minimally invasive and allows the anatomical reconstruction of the torn coracoclavicular ligaments in one step with a permanent implant that does not have to be removed in a second operation. This clinical pilot study is the first to describe the new method of navigated suture button implantation with the future aim of further reducing surgical invasiveness and further increasing surgical precision. MATERIALS AND METHODS: 10 patients with a Rockwood 3b/5 injury could be included in the prospective study (DRKS00031855) within 5 months according to inclusion and exclusion criteria. Surgical stabilization was performed with a suture button system via a navigated coracoclavicular drill tunnel. Demographic and radiological data as well as information on health and shoulder function were collected from patient records, X-rays, DVT scan and 3 questionnaires (DASH, NHS and Eq. 5D) at the preoperative, intraoperative and postoperative (discharge, 6 weeks and 3 months) time points. RESULTS: All operations could be performed within 8.8 days (± 6.81) after trauma. The average operation time was 50.3 min (± 8.81). The mean distance of the drill hole in the clavicle to the AC joint was 26.6 mm (± 2.63). The radiologically measured vertical coracoclavicular distance was 38.8 mm (± 6.16) at discharge and 41.11 mm (± 7.51) at 3 months. This loss of reduction was not statistically significant. In contrast, the DASH, NHS and Eq. 5D results showed significant improvement from discharge to 3 months postoperatively. CONCLUSION: Image-guided 3D C-arm navigated AC joint suture button stabilization is feasible in everyday surgical practice. It may be possible to achieve a further reduction in invasiveness while at the same time increasing the accuracy of implant positioning. Further clinical studies with a larger number of patients and a longer follow-up period are necessary to enable a comparison with conventional methods.

Primary Radial Nerve Lesions in Humerus Shaft Fractures-Revision or Wait and See.

Background: This study investigates the surgical state-of-the-art procedure for humeral shaft fractures with primary radial nerve palsy based on its own case series in relation to the current and established literature. Methods: Retrospective review of treated cases between January 2018 and December 2022 describing radial nerve palsy after humerus shaft fractures, radiological fracture classification, intraoperative findings, surgical procedure, patient follow-up and functional outcome. Results: A total of 804 patients (463 women and 341 men) with humerus shaft fractures were identified. A total of 33 patients showed symptomatic lesions of the radial nerve (4.1%). The primary lesion was identified in 17 patients (2.1%). A broad and inhomogeneous distribution of fractures according to the AO classification was found. According to the operative reports, the distraction of the radial nerve was found eleven times, bony interposed three times and soft tissue constricted/compressed three times. In every case the radial nerve was surgically explored, there was no case of complete traumatic nerve transection. Four intramedullary nails and thirteen locking plates were used for osteosynthesis. Complete recovery of nerve function was seen in 12 cases within 1 to 36 months. Three patients still showed mild hypesthesia in the thumb area after 18 months. Two patients were lost during follow-up. Conclusions: With this study, we support the strategy of early nerve exploration and plate osteosynthesis in humeral fractures with primary radial nerve palsy when there is a clear indication for surgical fracture stabilisation. In addition, early exploration appears sensible in the case of palsies in open fractures and secondary palsy following surgery without nerve exposure as well as in the case of diagnostically recognisable nerve damage. Late nerve exploration is recommended if there are no definite signs of recovery after 6 months. An initial wait-and-see strategy with clinical observation seems reasonable for primary radial nerve palsies without indication for surgical fracture stabilisation.

3D C-arm navigated acromioclavicular joint stabilization.

INTRODUCTION: Surgical treatment options for acromioclavicular joint separations are varied. Frequently, suspension devices (SD) are inserted for stabilization under arthroscopic view. This study investigates the feasibility and accuracy of three-dimensional (3D) digital-volume-tomography (DVT) C-arm navigated implantation with regard to the general trend toward increasingly minimally invasive procedures. MATERIALS AND METHODS: The implantation of a TightRope® suture button system (SD) via a navigated vertical drill channel through the clavicle and coracoid was investigated in 10 synthetic shoulder models with a mobile isocentric C-arm image intensifier setup in the usual parasagittal position. Thereby, in addition the placement of an additive horizontal suture cerclage via a navigated drill channel through the acromion was assessed. RESULTS: All vertical drill channels in the Coracoclavicular (CC) direction could be placed in a line centrally through the clavicle and the coracoid base. The horizontal drill channels in the Acromioclavicular (AC) direction ran strictly in the acromion, without affecting the AC joint or lateral clavicle. All SD could be well inserted and anchored. After tensioning and knotting of the system, the application of the horizontal AC cerclage was easily possible. The image quality was good and all relevant structures could be assessed well. CONCLUSION: Intraoperative 3D DVT imaging of the shoulder joint using a mobile isocentric C-arm in the usual parasagittal position to the patient is possible. Likewise, DVT navigated SD implantation at the AC joint in CC and AC direction on a synthetic shoulder model. By combining both methods, the application in vivo could be possible. Further clinical studies on feasibility and comparison with established methods should be performed.

First experiences with a surgery supporting computer system in regard to education, efficiency and complications.

Purpose: Since October 2019 a computer software named SPM (surgical process manager) is used in a Level I Trauma center. Workflows were developed for distinct surgical procedures (distal radius fractures, proximal femur fractures, ankle fractures, proximal humerus fractures and vertebral fractures). In addition, these workflows were separated in a shortened "Expert"-versions for consultants and a more detailed "Learner"- versions for residents.This investigation was intended to show, if and what kind of benefits in regard to efficiency (incision to suture and suture to incision time), education and complications a surgery supporting software can bring. Methods: SPM was used in 90 cases during October 2019 to June 2022. A control trial with 108 patients was developed, including patients of the same age, having same kind of injuries, receiving the same surgery technique without using the SPM.The software was installed on the computer in the operation room, projected on head monitors and operated by a foot pedal. Complications could also be documented using the pedal.Groups were divided in surgical procedures and fracture type, qualification of the surgeon, complications and surgery time. Surgery times were taken from the hospital computer system (SAP IS-H). A statistical analysis was performed by using the chi square and Fischer exact test with significance set at a P value <0.05. Results: In 51 cases the software was used for the distal radius (control group 54 patients), in 20 cases for Weber fractures (control group 21 patients), in 9 cases for the proximal femur (control group 19 patients), in 5 cases for vertebral fractures (control group 7 patients) and in 5 cases for the proximal humerus (control group 6 patients).Time from incision to closure was significant higher in the intervention group (49 vs 42 min, p- value 0,018) and wasn't significant lower in the "expert" group, fixing radius and ancle fractures (39 to 46 min, p value 0,186).Comparing the SPM and control group concerning closing to incision time, no difference could be observed (56 to 58,5 min, p value 0,828).The greatest time deviation between "Learners"und "Experts"was observed in reduction and fixation (p value 0,006) in ankle fractures. The "Expert"group also needed less time for the approach (p value 0,008) in case of distal radius fractures.Unexpected events were more often observed in the intervention group (5,5 vs 3,7 %). Conclusions: A surgery supporting computer system might be a good tool for detecting and optimizing workflows in the operation room and for improving and analyzing the training of residents and surgical assistants.In addition, it offers the opportunity to document intraoperative complications. However, a saving of time wasn't observed in this study. Further investigations with bigger number of cases and a longer follow-up are necessary to proof these findings statistically.

Sacroiliac versus transiliac-transsacral screw osteosynthesis in osteoporotic pelvic fractures: a biomechanical comparison.

INTRODUCTION: Pelvic fractures were often associated with high-energy trauma in young patients, but data show a significant increase in osteoporotic pelvic fractures in old age due to the progressive demographic change. There is an ongoing discussion about the best fixation techniques, which are ranging from lumbopelvic fixation to sacral bars or long transiliac-transsacral (TITS) screws. This study analyzes TITS screw osteosynthesis and sacroiliac screw osteosynthesis (SI), according to biomechanical criteria of fracture stability in osteoporotic human pelvic cadavers ex vivo. METHODS: Ten osteoporotic cadaveric pelvises were randomized into two groups of 5 pelvises each. An FFP-IIc fracture was initially placed unilaterally and subsequently surgically treated with a navigated SI screw or a TITS screw. The fractured side was loaded in a one-leg stance test setup until failure. Interfragmentary movements were assessed by means of optical motion tracking. RESULTS: No significant difference in axial stiffness were found between the SI and the TITS screws (21.2 ± 4.9 N and 18.4 ± 4.1 N, p = 0.662). However, there was a significantly higher stability of the fracture treatment in the cohort with TITS-screws for gap angle, flexion, vertical movement and overall stability. The most significant difference in the cycle interval was between 6.000 and 10.000 for the gap angle (1.62 ± 0.25° versus 4.60 ± 0.65°, p = 0.0001), for flexion (4.15 ± 0.39 mm versus 7.60 ± 0.81 mm, p = 0.0016), interval 11.000-15.000 for vertical shear movement (7.34 ± 0.51 mm versus 13.99 ± 0.97 mm, p < 0.0001) and total displacement (8.28 ± 0.66 mm versus 15.53 ± 1.07 mm, p < 0.0001) for the TITS and the SI screws. CONCLUSIONS: The results of this biomechanical study suggest a clear trend towards greater fracture stability of the TITS screw with significantly reduced interfragmentary movement. The application of a TITS screw for the treatment of the osteoporotic pelvic ring fracture may be prioritized to ensure the best possible patient care.

Neutrophil-derived catecholamines mediate negative stress effects on bone.

Mental traumatization is associated with long-bone growth retardation, osteoporosis and increased fracture risk. We revealed earlier that mental trauma disturbs cartilage-to-bone transition during bone growth and repair in mice. Trauma increased tyrosine hydroxylase-expressing neutrophils in bone marrow and fracture callus. Here we show that tyrosine hydroxylase expression in the fracture hematoma of patients correlates positively with acknowledged stress, depression, and pain scores as well as individual ratings of healing-impairment and pain-perception post-fracture. Moreover, mice lacking tyrosine hydroxylase in myeloid cells are protected from chronic psychosocial stress-induced disturbance of bone growth and healing. Chondrocyte-specific ß2-adrenoceptor-deficient mice are also protected from stress-induced bone growth retardation. In summary, our preclinical data identify locally secreted catecholamines in concert with ß2-adrenoceptor signalling in chondrocytes as mediators of negative stress effects on bone growth and repair. Given our clinical data, these mechanistic insights seem to be of strong translational relevance.

Computer-Based Mechanobiological Fracture Healing Model Predicts Non-Union of Surgically Treated Diaphyseal Femur Fractures.

As non-unions are still common, a predictive assessment of healing complications could enable immediate intervention before negative impacts for the patient occur. The aim of this pilot study was to predict consolidation with the help of a numerical simulation model. A total of 32 simulations of patients with closed diaphyseal femoral shaft fractures treated by intramedullary nailing (PFNA long, FRN, LFN, and DePuy Synthes) were performed by creating 3D volume models based on biplanar postoperative radiographs. An established fracture healing model, which describes the changes in tissue distribution at the fracture site, was used to predict the individual healing process based on the surgical treatment performed and full weight bearing. The assumed consolidation as well as the bridging dates were retrospectively correlated with the clinical and radiological healing processes. The simulation correctly predicted 23 uncomplicated healing fractures. Three patients showed healing potential according to the simulation, but clinically turned out to be non-unions. Four out of six non-unions were correctly detected as non-unions by the simulation, and two simulations were wrongfully diagnosed as non-unions. Further adjustments of the simulation algorithm for human fracture healing and a larger cohort are necessary. However, these first results show a promising approach towards an individualized prognosis of fracture healing based on biomechanical factors.

Intraoperative 3D imaging in plate osteosynthesis of proximal humerus fractures.

INTRODUCTION: Proximal humerus fractures are common and often associated with osteoporosis in the elderly. Unfortunately, the complication and revision rate for joint-preserving surgical treatment using locking plate osteosynthesis is still high. Problems include insufficient fracture reduction and implant misplacement. Using conventional intraoperative two dimensional (2D) X-ray imaging control in only two planes, a completely error-free assessment is not possible. MATERIALS AND METHODS: The feasibility of intraoperative three-dimensional (3D) imaging control for locking plate osteosynthesis with screw tip cement augmentation of proximal humerus fractures was retrospectively studied in 14 cases with an isocentric mobile C-arm image intensifier set up parasagittal to the patients. RESULTS: The intraoperative digital volume tomography (DVT) scans were feasible in all cases and showed excellent image quality. One patient showed inadequate fracture reduction in the imaging control, which then could be corrected. In another patient, a protruding head screw was detected, which could be replaced before augmentation. Cement distribution in the humeral head was consistent around the screw tips with no leakage into the joint. CONCLUSION: This study shows that insufficient fracture reduction and implant misplacement can be easily and reliably detected by intraoperative DVT scan with an isocentric mobile C-arm set up in the usual parasagittal position to the patient.

Blade Augmentation in Nailing Proximal Femur Fractures-An Advantage despite Higher Costs?

BACKGROUND: Proximal femoral fractures occur with increasing incidence, especially in the elderly. Commonly used implants for surgical treatment are cephalomedullary nails. To increase stability, a perforated femoral neck blade can be augmented with cement. The study investigated whether this results in a relevant clinical advantage and justifies the higher cost. MATERIALS AND METHODS: This is a single-center retrospective study of 620 patients with proximal femur fractures treated with cephalomedullary nailing. Between January 2016 and December 2020, 207 male and 413 female patients were surgically treated with a proximal femur nail (DePuy Synthes) using a perforated blade and cement augmentation in cases with severe osteoporosis. Primary outcome measures were the rate of cut-out, tip apex distance and the positioning of the blade in the femoral head. Secondary outcome measures were the implant costs and operating times. RESULTS: Of the 620 femoral neck blades, 299 were augmented with cement. A total of six cut-outs were seen in the first 3 months after the operation. There were three in the cement-augmented group (CAB = cement-augmented blade) and three in the conventional group (NCAB = non-cement-augmented blade). There was a significant positive correlation between age and augmentation, with a mean difference of 11 years between the two groups (CAB 85.7 ± 7.9 vs. NCAB 75.3 ± 15.1; p < 0.05). There was no difference in the tip-apex distance (CAB 15.97 vs. 15.69; p = 0.64) or rate of optimal blade positions between the groups (CAB 81.6% vs. NCAB 83.2%; p = 0.341). Operation times were significantly longer in the cemented group (CAB 62.6 21.2 min vs. NCAB 54.1 7.7 min; p < 0.05), and the implant cost nearly doubled due to augmentation. CONCLUSION: When the principles of anatomic fracture reduction, optimal tip-apex distance and optimal blade position are combined with cement augmentation in cases of severe osteoporosis, a cut-out rate of less than 1% can be achieved. Nevertheless, it should be noted that augmentation remains expensive and prolongs surgery time without definite proof of mechanical superiority.

Influence of Weight Bearing on Postoperative Complications after Surgical Treatment of the Lower Extremity.

PURPOSE: In order to prevent implant failure and secondary fracture dislocation, it is often recommended that patients perform partial weight-bearing after surgery of the lower extremity. Previous examinations showed that patients are often not able to follow these instructions. In this study, patients who had undergone surgery of the lower extremity were studied in order to analyze whether incorrect loading influenced the number and severity of complications. METHODS: Fifty-one patients were equipped with electronic shoe insoles, which measure loading and other parameters. The measurement period was 24 to 102 hours. Median duration of follow-up was 490 days. The primary outcome parameter was postoperative complications leading to revision surgery. Statistical analysis was performed using the chi-square and Fisher exact tests with significance set at a p < 0.05. RESULTS: Seven out of fifty-one patients had postoperative complications. Four wound complications, one implant failure, chronic instability after fracture of the tibia, and one implant loosening of a hip prosthesis were recorded. In total, 26 of 39 patients were not able to follow the postoperative instructions. Five of the twenty-six patients with difficulties in partial weight-bearing suffered a postoperative complication. In comparison, only 2 of the other 25 patients were affected. There was no statistically significant correlation between high weight-bearing and occurrence of complications (p = 0.29). CONCLUSION: Most of the patients were unable to follow the surgeon's instructions for partial weight-bearing. Excessive loading did not seem to influence the number and severity of postoperative complications, especially regarding implant failure. Therefore, we should continue with measurements and reevaluate the "partial weight-bearing doctrine".

Epidemiology, patterns, and mechanisms of pediatric trauma: a review of 12,508 patients.

BACKGROUND: Pediatric traumas are common and remain a unique challenge for trauma surgeons. Demographic data provide a crucial source of information to better understand mechanisms and patterns of injury. The aim of this study was to provide this information to improve treatment strategies of potentially preventable morbidity and mortality in children. MATERIAL AND METHODS: A retrospective review of every pediatric trauma treated in the emergency department (ED) between 2015 and 2019 was performed. Inclusion criteria were the age between 0 and 14 years and admission to the ED after trauma. Demographic data, time of presentation, mechanism of injury and pattern of injury, treatment, and outcome were analyzed. Different injury patterns were assessed in relation to age group, sex, mechanism of injury and treatment. RESULTS: A total of 12,508 patients were included in this study. All patients were stratified into five age groups: babies under the age of 1 (8.8%), toddlers between 1 and 3 (16.8%), preschool children between 4 and 6 (19.3%), young school children between 7 and 10 (27.1%), and young adolescents between 11 and 14 (27.9%). The predominant sex in all age groups was male. 47.7% of patients were admitted between 4 and 10 pm; 14.8% of the patients arrived between 10 pm and 8 am. Peak months of admissions were May to July. Overall, 2703 fractures, 2924 lacerations and superficial tissue injury, 5151 bruises, 320 joint dislocations, 1284 distortions, 76 burns, and 50 other injuries were treated. Most common mechanisms for fractures were leisure activities, falls, and sports-related activities. Forearm fractures were the most common fractures (39.5%) followed by humerus fractures (14%) and fractures of the hand (12.5%). A total of 700 patients with fractures (25.9%) needed surgery. 8.8% of all patients were hospitalized for at least one day. 4 patients died in the hospital (0.03%). CONCLUSION: Despite of higher risk, severe injuries in children are rare. Minor injuries and single fractures are common. Treatment should be managed in specialized centers to ensure an interdisciplinary care and fast recovery. Peak times in the late afternoon and evening and summer months should be taken into consideration of personnel planning.

Radial vs. Dorsal Approach for Elastic Stable Internal Nailing in Pediatric Radius Fractures-A 10 Year Review.

BACKGROUND: Forearm fractures are one of the most common fractures in children. Over the last years, a tendency towards surgical treatment was seen, especially closed reduction and internal fixation with elastic stable internal nailing (ESIN). Despite an overall low complication rate being described, a risk of intraoperative complications remains. MATERIAL AND METHODS: A total of 237 patients (mean age 8.3 ± 3.4 (1-16) years) with forearm or radius fractures treated with ESIN between 2010 and 2020 were included in the study. The retrospective review of 245 focused on fracture pattern, pre- and postoperative fracture angulation, intra- and postoperative complications, and surgical approach for nail implant. The fracture pattern and pre- and postoperative angulation were measured radiographically. Complications such as ruptures of the extensor pollicis longus (EPL) tendon and sensibility disorders of the superficial radial nerve were further analyzed. RESULTS: In 201 cases (82%), we performed a dorsal approach; 44 fractures (17.9%) were treated with a radial approach. In total, we found 25 (10%) surgery-related complications, of which 21 (8.6%) needed further surgical treatment. In total, we had 14 EPL ruptures (5.7%), 4 sensibility disorders of the superficial radial nerve (1.6%), 2 refractures after implant removal (0.8%), 2 superficial wound infections (0.8%), and 1 child with limited range of motion after surgery (0.4%). No statistical significance between pre- and postoperative angulation correlated to fracture patterns or diameter of the elastic nail was seen. As expected, there was a significant improvement of postoperative angulation. Using radial approach in distal radial fractures showed a lower rate of surgical related complications, 2.3% of which need further surgical treatment as well as better postoperative angulations compared to the dorsal approach (8.5%). CONCLUSION: Especially due to the low risk of damaging the EPL tendon, the radial approach showed a lower complication rate which needed further surgical treatment. The risk of lesions of the superficial radial nerve remains.

ESIN in femur fractures in children under 3: is it safe?

BACKGROUND: Pediatric femur fractures are a major trauma in children. Different treatment algorithms have been developed but indications for surgical treatment, especially in very young patients, are still controversial. Literature recommends surgical stabilization with elastic-stable intramedullary nailing (ESIN) starting at the age of 3 and non-operative treatment in younger patients. This study sought to present the outcome of patients younger than 3 years of age treated with ESIN for femur fractures. MATERIALS AND METHODS: Inclusion criteria were patients younger than 3 treated with ESIN in femur fractures. Patient demographics, fracture characteristics, mechanism of injury, outcomes and complications were recorded using charts and X-rays. Primary outcome measures were time to mobility, fracture consolidation and surgical-related complications. RESULTS: Between 2010 and 2020, 159 patients were treated with ESIN in femur fractures in our institution. A total of 30 patients met the criteria. The mean age was 2.1 ± 0.7 years (13 months-2.9 years). Most common mechanism was fall from standing height (60%). Other mechanisms were motor vehicle accidents as a pedestrian (10%) or as a passenger (10%) as well as direct blow trauma (20%). Femoral shaft fracture was the most common injury (80%). 5 subtrochanteric and one distal metaphyseal femur fractures were found. Mean length of stay was 2.0 ± 1.3 days. Radiographic controls were performed on day 1, 14 and 6 weeks after surgery if not otherwise specified or if complications occurred. 4.6 ± 1.2 (n 2-7) X-rays were performed on average after surgery. First radiographic consolidation signs were seen after 2.4 ± 0.6 weeks. Only one child showed surgical-related complication with a leg length discrepancy of 1 cm. In 10% of the patients, shortening after surgery of 1.7 ± 1.4 mm (0.3-3.1 mm) occurred. One child initially treated with traction therapy showed skin irritations and was operated with ESIN. No non-union or ESIN-related complications were found. Mean follow-up was 5.1 ± 4.4 months (4-24 months). First independent mobilization was seen at an average of 3.4 ± 1.1 weeks (2-6 weeks) after surgery. Implant removal was performed after 3.2 ± 1.3 months (2-8 months). No refracture after implant removal occurred. CONCLUSION: Early results with ESIN show a reasonable and safe treatment option for femur fractures in toddlers and young children under the age of 3 with easy postoperative care, fast fracture union and early independent mobilization.

Mast Cells Trigger Disturbed Bone Healing in Osteoporotic Mice.

Mast cells are important tissue-resident sensor and effector immune cells but also play a major role in osteoporosis development. Mast cells are increased in numbers in the bone marrow of postmenopausal osteoporotic patients, and mast cell-deficient mice are protected from ovariectomy (OVX)-induced bone loss. In this study, we showed that mast cell-deficient Mcpt5-Cre R-DTA mice were protected from OVX-induced disturbed fracture healing, indicating a critical role for mast cells in the pathomechanisms of impaired bone repair under estrogen-deficient conditions. We revealed that mast cells trigger the fracture-induced inflammatory response by releasing inflammatory mediators, including interleukin-6, midkine (Mdk), and C-X-C motif chemokine ligand 10 (CXCL10), and promote neutrophil infiltration into the fracture site in OVX mice. Furthermore, mast cells were responsible for reduced osteoblast and increased osteoclast activities in OVX mice callus, as well as increased receptor activator of NF-κB ligand serum levels in OVX mice. Additional in vitro studies with human cells showed that mast cells stimulate osteoclastogenesis by releasing the osteoclastogenic mediators Mdk and CXCL10 in an estrogen-dependent manner, which was mediated via the estrogen receptor alpha on mast cells. In conclusion, mast cells negatively affect the healing of bone fractures under estrogen-deficient conditions. Hence, targeting mast cells might provide a therapeutic strategy to improve disturbed bone repair in postmenopausal osteoporosis. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Analysis of partial weight bearing after surgical treatment in patients with injuries of the lower extremity.

INTRODUCTION: After surgical treatment of injuries of the lower extremity, partial weight bearing is often suggested until soft tissue consolidation. It is doubtful, if this recommendation can be implemented, even in the case that a patient is performing partial weight bearing with a physical therapist. Consequently the question remains, if patients are able to implement partial weight bearing after surgery and which factors favor incompliance. MATERIALS AND METHODS: 49 patients, who underwent surgical treatment after injuries of the lower extremity, were equipped with electronic shoe insoles on both sides. Different weight bearing instructions were given depending on the type of injury and surgery (full weight bearing vs. 20 kg weight bearing vs. non-weight bearing). Besides loading, other factors like age, gender, weight and physical activity were evaluated. Statistical analysis was performed using Chi-square and Fisher's exact test with significance set at a p value < 0.05. RESULTS: 25 of the 40 patients, who had to perform non- or partial weight bearing, were not able to follow postoperative instructions (compliance rate 37.5%). The average loading of the whole collective was 32.6 kg (4.8-109.2 kg). The specification of loading had no statistically significant influence on real loading (p-value 0.39). Elderly patients were less able to follow instructions than younger patients (36 vs 30.2 kg). Physically active compared to non-active patients overloaded their injured extremity (37.8 vs 28.7 kg). Patients with a high body mass index (BMI) encountered more difficulties to perform partial weight bearing than lightweight patients (36.9 vs 25.1 kg). CONCLUSIONS: Most patients were not able to follow loading limitation, even a few days after surgery and even if the patients were trained by a physiotherapist. Excessive weight bearing-related complications should be evaluated.

How Safe and Time Consuming is the Surgical Training of Young Orthopaedic Surgeons? A Retrospective Analysis of Proximal Femur Fractures. / Wie sicher und zeitintensiv ist die operative Ausbildung in der Orthopädie und Unfallchirurgie ­ eine Auswertung von Ausbildungseingriffen am proximalen Femur.

BACKGROUND: Fractures of the proximal femur in the elderly population are rising. Teaching the appropriate surgical treatment of these fractures is of paramount importance. The aim of the study was to evaluate differences in outcome of surgical procedures between supervised trainees and senior surgeons. OBJECTIVE: Are there more surgical complications, poorer quality or an increased operating time if the procedure (in this case: fixation of proximal femur fractures) is performed by trainees under supervision in comparison to experienced surgeons. MATERIAL AND METHODS: All patients treated with the proximal femur nail antirotation (PFNA) between 2015 and 2016 at a level one trauma centre were included in this study. The retrospective review of the 299 patients compared supervised surgical trainees and senior surgeons. Parameters included operating time, tip apex distance, position of the blade, Hb-difference, transfusion rate, surgical complications as well as mortality, and were compared between the groups. RESULTS: 153 of 299 procedures were performed by supervised surgical trainees. In comparison to senior surgeons, there was no significant difference in operating time (WA 54.48 min; OA 60.47 min; p > 0,05), Hb-difference (WA 2.8 g/dl; OA 2.6 g/dl; p > 0.05), tip-apex distance (WA 21.2 mm; OA 20.5 mm, p = 0.37) or rate of surgical complications. There was no difference in the rate of optimal blade positions between the groups (WA 87.5%; OA 89.0%; p = 0.366). Furthermore, mortality showed no difference between the groups, but was greater in older patients or high ASA grade. CONCLUSION: Supervised surgical training during treatment of proximal femur fractures shows no increase in operating time, complications or mortality and no difference in quality. With the fast growth of the elderly population, surgical training of fragility fractures should receive more attention in the future.

[Surgical treatment strategies and their radiological potential for correction of proximal radius fractures in children and adolescents]. / Operative Versorgungsstrategien und deren radiologisches Korrekturpotenzial bei proximalen Radiusfrakturen des Kindes und Jugendlichen.

BACKGROUND AND OBJECTIVE: The isolated proximal radius fracture in children is a quite rare injury. In difference to adults a conservative treatment is often possible. But in case of increasing dislocation the indication for surgery is given. Options for an operative treatment are "closed reduction", "percutaneous reduction", "intramedullary nailing", "open reduction" with and without fixation. Aim of this study is to compare these procedures with each other. STUDY DESIGN AND METHODS: This was a retrospective investigation and 82 patients who underwent surgery after an isolated proximal radius fracture were included. Fracture types were classified according to the AO (working group for osteosynthesis questions)/OTA (Orthopedic Trauma Association) classification. The preoperative and postoperative degrees of axis deviation were compared and were considered to be a measure of the quality of treatment. RESULTS: The lowest degree of axis deviation resulted by open reduction and implantation of K­wires (15,8°) and implantation of headless compression screws (HCS, 16°). Closed reduction without any fixation resulted in 19°, with implantation of an TEN (titan elastic nail) in 20° and the open reduction without any fixation resulted in 21° of axis deviation. No correlation was observed concerning the fracture type and the postoperative axis deviation. CONCLUSION: The study shows that the postoperative result does not depend on the fracture type (according to the AO/OTA classification) but on the surgical procedure. Despite the good radiological results in open reduction and internal fixation this procedure should be reserved for difficult situations in which less invasive surgical procedures fail, to avoid aseptic bone necrosis.

Early Results in Non-Displaced Femoral Neck Fractures Using the Femoral Neck System.

INTRODUCTION: Femoral neck fractures in the elderly are a major event and are rising in incidence over the last decade. Advancing age and numerous comorbidities largely account for high mortality rate and require geriatric expertise. Treatment options are total hip arthroplasty (THA), hemiarthroplasty (HA) or osteosynthesis. Literature suggests THA or HA for better outcomes, although no clear guidelines exist. MATERIAL AND METHODS: A retrospective chart review was performed of 63 patients (80 ± 11 years; 32 women, 31 men) with Garden one femoral neck fractures treated between June 2018 and June 2020 with either HA or internal fixation with the Femoral Neck System (FNS). Primary outcome measures were surgical and non-surgical complication rates and best achievable mobilization during the hospital stay. RESULTS: Thirty four patients were treated with HA, and 29 with the FNS. Mobilization was measured using the Charité Mobility Index (CHARMI). No difference between age, ASA, CCI or preoperative CHARMI was found. The CHARMI was significantly lower in the HA group. No difference in surgical complications was found. The HA cohort showed more non-surgical complications, a longer ICU stay and more blood transfusions. Hospitalization was significant longer in the HA than the FNS cohort (15.1 ± 5.1 vs 9.8 ± 3.8 days). Radiographic controls were performed after 6 and 12 weeks. The FNS group showed a mean shortening of 3.3 mm. 4 of 21 patient had shortening >5 mm. 20 of 21 patients showed radiographic signs of bone healing after 3 months. CONCLUSION: Early results with the FNS show faster recovery than patient with hemiarthroplasty. Internal fixation with the FNS may be an option in non-displaced femoral neck fractures. Further studies should be performed to better evaluate the FNS compared to traditional internal fixation methods and arthroplasty.

Perception of quality of intraoperative fluoroscopy and the influence on postoperative management: an international survey.

PURPOSE: Intraoperative precise visualization of fractures and assessment of the quality of reduction is essential in orthopedic trauma surgery. Fluoroscopic skills will lead to an increased detection rate of minimal abnormalities needing revision intraoperatively. The definition of fluoroscopic skills and the interpretation of acceptable "minimal abnormalities" remains somehow unclear. The purpose of this study was to analyze the subjective quality assessment of intraoperative radiographs (IR) and whether they are influenced by cultural and demographic factors. Furthermore, we aimed to answer the question whether the indication for revision surgery is international comparable or rather influenceable by cultural aspects. METHODS: Intraoperative radiographs of 30 patients operated for an ankle or radius fracture were selected for an international survey. In total, 22 patients were randomly selected from an already existing database and eligible for inclusion if reduction was accomplished during initial operation without planed revision. Eight patients of this group had undergone an unplanned revision surgery (26.6%). Fifteen orthopedic trauma surgeons from three different countries answered this survey. All raters were senior consultants. RESULTS: The quality of reduction was rated as good in both the AP (7.95 of 10) and lateral (7.84 of 10) views. The inter-observer reliability was substantially weaker in Country B (kappa of 0.23) compared to Countries A (p value < 0.05) and C (range 0.33-0.43). In only 33% of the cases the raters requested a postoperative radiograph. This was significantly fewer (p value < 0.001) in Country A. The frequency of postoperative requested CT's was comparable between the countries. CONCLUSION: This study showed acceptable IR assessment in terms of quality rating. Furthermore, it revealed substantial differences in the postoperative decision-making process in different countries, especially regarding the necessity for postoperative radiographs. This suggests that definition for indication of revision surgery is culturally influenced.