Effects of Iliosacral Joint Immobilization on Walking after Iliosacral Screw Fixation in Humans.

BACKGROUND: Pelvis fractures are commonly stabilized by surgical implants to facilitate their healing. However, such implants immobilize the iliosacral joint for up to a year until removal. We report how iliosacral joint immobilization affects the walking of patients. METHODS: The gaits of patients with immobilized sacroiliac joints after unstable pelvic fracture (n = 8; mean age: 45.63 ± 23.19; five females and three males) and sex- and age-matched healthy control individuals (n = 8; mean age: 46.50 ± 22.91; five females and three males) were recorded and analyzed using a motion capture system. The forces between the tread and feet were also recorded. Standard gait parameters as well as dynamic patterns of joint angles and moments of the lower extremities were analyzed using the simulation software OpenSim. RESULTS: With the exception of hip extensor strength, the monitored joint parameters of the patients showed task-dependent deviations during walking, i.e., plantarflexor force was increased when stepping on an elevated surface, as were hip flexion and extensor moments, knee flexion and extensor moments, as well as ankle dorsiflexion and the associated negative plantarflexor force during stance on the elevated surface. CONCLUSIONS: Iliosacral joint fixation causes reduced forward and upward propulsion and requires an extended range of hip motion in the sagittal plane. Patients show significant mobility limitation after iliosacral screw fixation.

Physiological Femoral Condylar Morphology in Adult Knees-A MRI Study of 517 Patients.

BACKGROUND: In the age of individualised arthroplasty, the question arises whether currently available standard implants adequately consider femoral condylar morphology (FCM). Therefore, physiological reference values of FCM are needed. The aim was to establish physiological reference values for anterior (ACO) and posterior condylar offset (PCO) as well as for the length of the medial (LMC) and lateral femoral condyles (LLC). METHODS: The knee joints of 517 patients (mean age: 52.3 years (±16.8)) were analysed retrospectively using MRI images. Medial (med) and lateral (lat) ACO and PCO, as well as LMC and LLC, were measured. All FCM parameters were examined for association with age, gender, side and osteoarthritis. RESULTS: Mean ACOmed was 2.8 mm (±2.5), mean ACOlat was 6.7 mm (±2.3), mean PCOmed was 25.7 mm (±4.6), mean PCOlat was 23.6 mm (±3.0), mean LMC was 63.7 mm (±5.0) and mean LLC was 64.4 mm (±5.0). Except for PCOmed, the mean values of all other FCM parameters were significantly higher in male knees compared to female knees. ACOmed and PCOmed showed significant side-specific differences. There were no significant differences in relation to age and osteoarthritis. CONCLUSION: The study showed significant differences in FCM side- and gender-specifically in adult knees. These aspects should be considered in the discussion of individual and gender-specific knee joint replacement.

Morphological Analysis of the Tibial Slope in 720 Adult Knee Joints.

Background: The tibial slope (TS) defines the posterior inclination of the tibial plateau (TP). The "individual physiological" TS plays a crucial role in knee-joint stability and should be taken into account in knee-joint surgery. The aim of this study was to analyse the specific morphology of the TS for the medial (med) and lateral (lat) TP in relation to patient characteristics and the measurement method. Methods: In this retrospective study, MRI images of knee joints from 720 patients (mean age: 49.9 years [±17.14]) were analysed. The TS was assessed using two established methods according to Hudek (TSH) and Karimi (TSK) for the med and lat TP and gender/side specificity was analysed. Results: TSH for the med and lat TP showed significantly (p < 0.001) different values compared to TSK (TSKmed: 2.6° (±3.7), TSHmed: 4.8° (±3.5); TSKlat: 3.0° (±4.0), TSHlat: 5.2° (±3.9)). The angles of the lat TP were significantly higher than those of the med TP (TSK: p < 0.001; TSH: p = 0.002). Females showed a higher med and lat TS compared to males (p < 0.001). Conclusions: The measurement method has an influence on the values of the TS in knee-joint MRIs. The TS is significantly different for the med and lat TP regardless of the measurement method. There are gender-specific differences for the TS.

Diagnostic value of chest radiography in the early management of severely injured patients with mediastinal vascular injury.

INTRODUCTION: Time is of the essence in the management of severely injured patients. This is especially true in patients with mediastinal vascular injury (MVI). This rare, yet life threatening injury needs early detection and immediate decision making. According to the ATLS guidelines [American College of Surgeon Committee on Trauma in Advanced Trauma Life Support (ATLS®), 10th edn, 2018], chest radiography (CXR) is one of the first-line imaging examinations in the Trauma Resuscitation Unit (TRU), especially in patients with MVI. Yet thorough interpretation and the competence of identifying pathological findings are essential for accurate diagnosis and drawing appropriate conclusion for further management. The present study evaluates the role of CXR in detecting MVI in the early management of severely injured patients. METHOD: We addressed the question in two ways. (1) We performed a retrospective, observational, single-center study and included all primary blunt trauma patients over a period of 2 years that had been admitted to the TRU of a Level-I Trauma Center. Mediastinal/chest (M/C) ratio measurements were calculated from CXRs at three different levels of the mediastinum to identify MVI. Two groups were built: with MVI (VThx) and without MVI (control). The accuracy of the CXR findings were compared with the results of whole-body computed tomography scans (WBCT). (2) We performed another retrospective study and evaluated the usage of sonography, CXR and WBCT over 15 years (2005-2019) in level-I-III Trauma Centers in Germany as documented in the TraumaRegister DGU® (TR-DGU). RESULTS: Study I showed that in 2 years 267 patients suffered from a significant blunt thoracic trauma (AIS ≥ 3) and met the inclusion criteria. 27 (10%) of them suffered MVI (VThx). Through the initial CXR in a supine position, MVI was detected in 56-92.6% at aortic arch level and in 44.4-100% at valve level, depending on different M/C-ratios (2.0-3.0). The specificity at different thresholds of M/C ratio was 63.3-2.9% at aortic arch level and 52.9-0.4% at valve level. The ROC curve showed a statistically random process. No significant differences of the cardiac silhouette were observed between VThx and Control (mean cardiac width was 136.5 mm, p = 0.44). Study II included 251,095 patients from the TR-DGU. A continuous reduction of the usage of CXR in the TRU could be observed from 75% in 2005 to 25% in 2019. WBCT usage increased from 35% in 2005 to 80% in 2019. This development was observed in all trauma centers independently from their designated level of care. CONCLUSION: According to the TRU management guidelines (American College of Surgeon Committee on Trauma in Advanced Trauma Life Support (ATLS®), 10th edn, 2018; Reissig and Kroegel in Eur J Radiol 53:463-470, 2005) CXR in supine position is performed to detect pneumothorax, hemothorax and MVI. Our study showed that sensitivity and specificity of CXR in detecting MVI was statistically and clinically not reliable. Previous studies have already shown that CXR is inferior to sonography in detecting pneumothorax and hemothorax. Therefore, we challenge the guidelines and suggest that the use of CXR in the early management of severely injured patients should be individualized. If sonography and WBCT are available and reasonable, CXR is unnecessary and time consuming. The clinical reality reflected in the usage of CXR and WBCT over time, as documented in the TR-DGU, seems to support our statement.

Anatomic reduction of the sacroiliac joint in unstable pelvic ring injuries and its correlation with functional outcome.

PURPOSE: Reduction and percutaneous screw fixation of sacroiliac joint disruptions and sacral fractures are surgical procedures for stabilizing the posterior pelvic ring. It is unknown, however, whether smaller irregularities or the inability to achieve an anatomic reduction of the joint and the posterior pelvic ring affects the functional outcome. Here, the long-term well-being of patients with and without anatomic reduction of the posterior pelvis after sacroiliac joint disruptions is described. METHODS: Between 2011 and 2017, 155 patients with pelvic injuries underwent surgical treatment. Of these, 39 patients with sacroiliac joint disruption were examined by radiological images and computer tomography (CT) diagnostics and classified according to Tile. The functional outcome of the different surgical treatments was assessed using the short form health survey-36 (SF-36) and the Majeed pelvic score. RESULTS: Complete data sets were available for 31 patients, including 14 Tile type C and 17 type B injuries. Of those, 26 patients received an anatomic reduction, 5 patients obtained a shift up to 10 mm (range 5-10 mm). The SF-36 survey showed that the anatomic reduction was significantly better in restoring the patient's well being (vitality, bodily pain, general mental health and emotional well-being). Patients without this treatment reported a decrease in their general health status. CONCLUSIONS: Anatomic reduction was achieved in over 80% of patients in this study. When comparing the long-term well-being of patients with and without anatomic reduction of the posterior pelvis after sacroiliac joint disruptions, the results suggest that anatomical restoration of the joint is beneficial for the patients.

Analysis of trans-sacral corridors in stabilization of fractures of the pelvic ring.

Percutaneous screw fixation combined with pelvic reduction is a surgical technique used to stabilize fractures of the posterior pelvic ring. This is the standard surgical treatment of unstable posterior pelvic ring injuries. The primary goal of this treatment is an anatomic reduction and stable fixation. This has been shown to reduce pain and improve the patients' long-term well-being. The aim of this analysis was to determine the possible screw lengths and the positioning of the screws in the S1 and S2 sacral segments. A population of 697 pelvises from the Stryker Orthopaedic Modeling and Analytics database were analyzed. The dimensions of the S1 and S2 screw corridors were determined and after assessing for sacral dysmorphism, the correct screw placement was chosen to determine the necessary screw length for surgical treatment. The measurements of the screw lengths show a Gaussian distribution for the analyzed population. The percentage of dysmorphic pelvises for the S1 screw corridor was 31.3% and for the S2 corridor 8%. Average screw length for S1 was 163.8 ± 16.2 mm and for the S2 137.3 ± 9.5 mm. The results show that the S1/S2 axis cannot be used for a trans-sacral screw placement in every patient. The study shows that intraosseous screw corridors are present in 68.7% of the patients in the S1 position and in 92% at the S2 level where an intended implant can be placed fully intraosseous.

A retrospective study about functional outcome and quality of life after surgical fixation of insufficiency pelvic ring injuries.

BACKGROUND: Fragility fractures without significant trauma of the pelvic ring in older patients were often treated conservatively. An alternative treatment is surgery involving percutaneous screw fixation to stabilize the posterior pelvic ring. This surgical treatment enables patients to be mobilized quickly and complications associated with bedrest and temporary immobility are reduced. However, the functional outcome following surgery and quality of life of the patients have not yet been investigated. Here, we present a comprehensive study addressing the long-term well-being and the quality of life of patients with fragility pelvic ring fractures after surgical treatment. METHODS: Between 2011-2019, 215 geriatric patients with pelvic ring fractures were surgically treated at the university hospital in Göttingen (Germany). Of these, 94 patients had fragility fractures for which complete sets of computer tomography (CT) and radiological images were available. Fractures were classified according to Tile and according to the FFP classification of Rommens and Hofmann. The functional outcome of surgical treatment was evaluated using the Majeed pelvic score and the Short Form Health Survey-36 (SF-36). RESULTS: Thirty five tile type C and 48 type B classified patients were included in the study. After surgery eighty-three patients scored in average 85.92 points (± 23.39) of a maximum of 100 points using the Majeed score questionnaire and a mean of 1.60 points on the numerical rating scale ranging between 0 and 10 points where 0 points refers to "no pain" and 10 means "strongest pain". Also, the SF-36 survey shows that surgical treatment positively effects patients with respect to their general health status and by restoring vitality, reducing bodily pain and an increase of their general mental health. CONCLUSIONS: Patients who received a percutaneous screw fixation of fragility fractures of the posterior pelvic ring reported an overall positive outcome concerning their long-term well-being. In particular, older patients appear to benefit from surgical treatment. TRIAL REGISTRATION: Functional outcome and quality of life after surgical treatment of fragility fractures of the posterior pelvic ring, DRKS00024768. Registered 8th March 2021 - Retrospectively registered. Trial registration number DRKS00024768 .

Phosphorylation of RyR2 Ser-2814 by CaMKII mediates ß1-adrenergic stress induced Ca2+ -leak from the sarcoplasmic reticulum.

Adrenergic stimulation, while being the central mechanism of cardiac positive inotropy, is a universally acknowledged inductor of undesirable sarcoplasmic reticulum (SR) Ca2+ leak. However, the exact mechanisms for this remained unspecified so far. This study shows that Ca2+ /calmodulin-dependent protein kinase II (CaMKII)-specific phosphorylation of ryanodine receptor type 2 at Ser-2814 is the pivotal mechanism by which SR Ca2+ leak develops downstream of ß1-adrenergic stress by increase of the leak/load relationship. Cardiomyocytes with a Ser-2814 phosphoresistant mutation (S2814A) were protected from isoproterenol-induced SR Ca2+ leak and consequently displayed improved postrest potentiation of systolic Ca2+ release under adrenergic stress compared to littermate wild-type cells.

The rise in expression and activity of 11ß-HSD1 in human mesenchymal progenitor cells induces adipogenesis through increased local cortisol synthesis.

11ß-Hydroxysteroid dehydrogenase 1 (11ß-HSD1) plays an important role in pre-receptor glucocorticoid metabolism. This enzyme is expressed in bone, increases with age, and catalyzes the conversion of the inactive glucocorticoid cortisone into the active glucocorticoid cortisol and vice versa. Here we hypothesized that the physiological activity of 11ß-HSD1 to produce cortisol in human mesenchymal progenitor cells (hMSC) is principally sufficient to shift the differentiation potential in the direction of adipogenic. We thus investigated differentiating hMSCs and the mesenchymal stem cell line SCP-1 cultured under osteogenic conditions and stimulated with supra-physiological cortisone levels. The release of active cortisol into the medium was monitored and the influence on cell differentiation analyzed. We revealed an increase in 11ß-HSD1 expression followed by increased reductive activity of the enzyme, thereby inducing a more adipogenic phenotype of the cell models via cortisol with negative effects on osteogenesis. Through inhibition experiments with the specific inhibitor 10 j, we proved the enzyme specificity for cortisol synthesis and adipogenic differentiation. Increased expression of 11ß-HSD1 followed by higher cortisol levels might thus explain bone marrow adiposity followed by reduced bone quality and stability in old age or in situations of supra-physiological glucocorticoid exposure.

Of Cestodes and Men: Surgical Treatment of a Spinal Hydatid Cyst.

BACKGROUND: The cestode Echinococcus granulosus causes hydatid disease. In addition to manifestations in the liver and lung, it can lead to cystic lesions in the spine. CASE DESCRIPTION: We report a 42-year-old male patient with primary hydatid disease in the eighth thoracic vertebra. The only clinical symptom was chronic back pain. Although laboratory findings were normal, imaging displayed lytic destruction that raised the suspicion of a metastatic disease. Diagnostics of the thoraces and abdomen did not reveal other pathologic abnormalities. Follow-up magnetic resonance imaging (MRI) depicted a progressive compression of the spinal cord and inhomogeneous structure in the fat-suppressed sequences. Because the Jamshidi biopsy was inconclusive, the tumor board recommended surgery. Dorsal decompression, spondylodesis of T6-T10, and vertebral column resection of T8 with complete cyst removal were performed. The resected vertebrae showed a mucous-like lesion with white granular tissue interfusing the whole vertebral body. A pathologic examination and enzyme-linked immunosorbent assay confirmed E. granulosus. Thus chemotherapy with albendazole was initiated. A follow-up MRI of the whole spine confirmed complete remission and found no additional resettlements. The patient's back pain was resolved without neurologic deficits. CONCLUSIONS: For lytic manifestations of the vertebral column, hydatid cysts should be considered a differential diagnosis in addition to malignant metastasis, tuberculosis, and osteomyelitis. Thorough surgical resection and strict follow-up are necessary.