Mineralisation patterns in the subchondral bone plate of the humeral head

Purpose: Pathologic changes of the glenohumeral joint, like a long-standing overloading or an accident often lead to severe glenohumeral osteoarthritis, and a glenohumeral joint replacement could be necessary. Joint instability and glenoid loosening are the most common post-operative complications, which can be caused by eccentric loading of the glenoid, if the humeral head is malcentered. If these malcentered cases could be identified pre-operatively, the pathologic position of the humeral head could be fixed intra-operatively and complication may be prevented. Computed tomography osteoabsorptiometry (CT-OAM) is a useful method to determine the distribution of mineralisation in the subchondral bone as a marker for the long-term loading history of a joint. The objective of this study was to gain information about the mineralisation distribution in the subchondral bone plate of the humeral head. Methods: By the use of CT-OAM, the distribution of the subchondral mineralisation of 69 humeral heads was investigated and groups of mineralisation patterns were built. To evaluate if differences in age exist, the mean values of the two groups were compared using t test. Results: 49 humeral heads (71% of 69 specimens) showed bicentric subchondral mineralisation patterns with ventral and dorsal maxima, 20 humeral heads (29% of 69 specimens) could be classified as monocentric with a centro-dorsal maximum. We found no statistical significant difference between the age of the monocentric and the bicentric group on a significance level of 95%. Conclusion: We could show that stress distribution at the humeral head is typically bicentric with a ventral and dorsal maximum. However, other mineralisation patterns may occur under pathologic circumstances. The pre-operative identification of such cases by the use of CT-OAM could help to improve the post-operative results in shoulder surger

A comparison of subchondral bone mineralization between the glenoid cavity and the humeral head on 57 cadaverous shoulder joints

Purpose: Mineralization distribution of the subchondral bone plate can be used as a marker for long-term stress distribution in diarthrodial joints. Severe injuries or pathological changes of the glenohumeral joint often end in osteoarthritis, where shoulder arthroplasty has become the treatment of choice. The computed tomography osteoabsorptiometry (CT-OAM) is a non-invasive method to determine the distribution of the mineralization of the subchondral bone plate in vivo, which is an important factor concerning the implantation of orthopedic endoprostheses. The aim of this study was to investigate the mineralization of both joint partners of the glenohumeral joint and to compare them with each other. Methods: The distribution of the mineralization of the subchondral bone plate of 57 shoulder specimens was determined by means of CT-OAM. To evaluate a correlation between age and localization of subchondral mineralization maxima, the Chi-square test correlation test was applied. Results: Forty-nine glenoid cavities (86%) showed a bicentric mineralization distribution pattern with anterior and posterior maxima, only 8 glenoid cavities (14%) revealed a monocentric mineralization pattern with anterior maxima. Forty-five humeral heads (79%) showed a bicentric distribution pattern with anterior and posterior maxima, 12 humeral heads (21%) could be classified as monocentric with a centro-posterior pronounced maximum. Conclusions: We could demonstrate that stress distribution in both joint partners of the glenohumeral joint is inhomogeneous and characteristically bicentric due to the physiological incongruity. Monocentric mineralization patterns can result as a cause of age-related loss of incongruit

Mineralisation and mechanical strength of the glenoid cavity subchondral bone plate

Purpose: Failures in total shoulder replacements are often due to aseptic loosening of the glenoid component; the subchondral bone plate is an important factor governing primary fixation of implant materials. Therefore, we investigated characteristic mineralisation patterns of the subchondral bone plate, which demonstrate long-term stress on articular surfaces, age-related changes, postsurgical biomechanical situations and regions of fixation. Using computed tomography osteo-absorptiometry (CT-OAM), these distribution patterns can be demonstrated in vivo. The aim of this study was to investigate the relationship between subchondral bone-plate mineralisation measured with CT-OAM and the mechanical strength measured by indentation. Methods: A total of 32 cadaverous glenoid cavities were evaluated by CT-OAM and indentation testing. Linear regression was used to compare mineralisation and strength of the subchondral bone plate. Results: Results showed two patterns of mineralisation distribution. Twenty-eight cavities were related to bicentric distribution pattern and four showed a single maximum. The correlation coefficient between CT-OAM density and subchondral bone-plate strength was determined to be between 0.62 and 0.96 (P < 0.02). Conclusions: Long-term stress affects not only the subchondral but also the underlying cancellous bone. It therefore can be assumed that mineralisation patterns of the subchondral bone plate continue in cancellous bone. Areas of high density could serve as anchoring locations for orthopaedic implants in resurfacing the glenoid cavit

Thickness distribution of the glenohumeral joint cartilage: a quantitative study using computed tomography

Purpose: Among late signs like sclerosis, cysts and osteophytes, alteration of cartilage is a common problem in osteoarthritis. To detect abnormal states in the glenohumeral joint, the physiologic distribution of the cartilage thickness must be known, which will allow physicians to better advise patients. High-resolution computed tomography (CT) data in soft tissue kernel provide highly accurate quantitative results and are a useful method to determine the geometrical situation of the glenohumeral joint. The objective of this study was to characterize the distribution of the thickness of the glenohumeral joint cartilage using CT. Methods: To investigate the distribution of thickness of the joint cartilage, CT images in soft tissue kernel of nine specimens were analyzed using image visualization software. Statistical analysis of the obtained data was performed using the ANOVA test. Results: Results showed different patterns in the glenoid cavity than in humeral head. Cartilage thickness in all glenoids showed maxima in the inferior and anterior portion, whereas central areas are covered with the thinnest cartilage layer. Maximum cartilage thickness in the humeral head was found in the central and superior parts. Conclusion: We could show that the distribution of cartilage thickness in the glenohumeral joint is not homogenous and that there exist several reproducible patterns. Evaluation of cartilage thickness in the glenohumeral joint is of high interest in basic and clinical research

Extraction of Biofilms From Ureteral Stents for Quantification and Cultivation-Dependent and -Independent Analyses

Ureteral stenting is a common surgical procedure, which is associated with a high morbidity and economic burden, but the knowledge on the link between biofilms on these stents, morbidity, and the impact of the involved microbiota is still limited. This is partially due to a lack of methods that allow for a controlled extraction of the biofilms from stents. Development of an appropriate in vitro model to assess prevention of biofilm formation by antimicrobial coatings and biomaterials requires a profound understanding of the biofilm composition, including the involved microbiota. This work describes an analytical pipeline for the extraction of native biofilms from ureteral stents for both cultivation-dependent and -independent analysis, involving a novel mechanical abrasion method of passing stent samples through a tapered pinhole. The efficiency of this novel method was evaluated by quantifying the removed biofilm mass, numbers of cultivable bacteria, calcium content, and microscopic stent analysis after biofilm removal using 30 clinical stent samples. Furthermore, the extraction of in vitro formed Escherichia coli biofilms was evaluated by universal 16S quantitative PCR, a cultivation-independent method to demonstrate efficient biofilm removal by the new approach. The novel method enables effective contamination-free extraction of the biofilms formed on ureteral stents and their subsequent quantification, and it represents a useful tool for comprehensive examinations of biofilms on ureteral stents

Nomenclature and treatment of secondary urethral strictures following primary hypospadias repair: weighing up academic principles and clinical pragmatism

Purpose!#!To ascertain renal cell carcinoma (RCC) financial toxicity on COVID-19 during the COVID-19 crisis as patients are struggling with therapeutic and financial implications.!##!Methods!#!An online survey was conducted from March 22 to March 25, 2020. It included baseline demographic, clinicopathologic, treatment-related information, anxiety levels related to COVID-19, questions related to financial concerns about COVID-19 as well as the validated 11-item COST measure.!##!Results!#!Five-hundred-and-thirty-nine patients (39%:58% male:female) from 14 countries responded. 23% of the patients did not feel in control of their financial situation but 8% reported being very satisfied with their finances. The median COST score was 21.5 (range 1-44). Metastatic patients who have not started systemic therapy had a COST score (19.8 range 2-41) versus patients on oral systemic therapy had a COST score (23.9 range 4-44). Patients in follow-up after surgery had a median COST score at 20.8 (range 1-40). A low COST scores correlated (p &amp;lt; 0.001) were female gender (r = 0.108), younger age (r = 0.210), urban living situation (r = 0.68), a lower educational level (r = 0.155), lower income (r = 0.165), higher anxiety about acquiring COVID-19 (r = 0.198), having metastatic disease (r = 0.073) and a higher distress score about cancer progression (r = 0.224).!##!Conclusion!#!Our data highlight severe financial impact of COVID-19. Acknowledging financial hardship and thorough counseling of cancer patients should be part of the conversation during the pandemic. Treatment and surveillance of RCC patients might have to be adjusted to contemplate financial and medical needs

Readability assessment of commonly used urological questionnaires

Purpose: This study was performed to assess readability of the most commonly used questionnaires in urology including a separate analysis of their single-items to identify questions that might be especially demanding for patients. Materials and Methods: The guidelines of the European Association of Urology were screened for recommended questionnaires. Readability was analyzed for complete questionnaires as well as their single-items separately using well established readability assessment tools, including Flesch-Kincaid grade level (FKGL), Simple Measure of Gobbledygook grade level (SMOG), Coleman-Liau Index (CLI), Gunning-Fog Index, and the Flesch Reading Ease formula. Results: A total of 13 questionnaires were included to the analysis. Calculation of grade levels (FKGL, SMOG, CLI, FGI) showed readability scores of 2.7th to 16.7th grade. Easiest readability as calculated by median grade levels was found for the short form of the International Consultation on Incontinence Questionnaires-Female Lower Urinary Tract Symptoms short form (FLUTS-SF) while the short form of the International Index of Erectile Function (IIEF-5) showed the hardest readability. Based on the FKGL between 0% (FLUTS-SF) and 80% (IIEF-5) of the single-items were written above the recommended grade levels. Conclusions: The questionnaires that are used most frequently in urology mainly show a satisfactory overall readability. Inadequate readability levels were not only found for individual questionnaires but also for single-items of the majority of assessed questionnaires. This requires consideration for the interpretation of results and when developing novel health-related surveys

The glenohumeral joint - a mismatching system? A morphological analysis of the cartilaginous and osseous curvature of the humeral head and the glenoid cavity

BACKGROUND: Radial mismatch, glenohumeral conformity ratios and differences between cartilaginous and osseous radii highly depend on the measured plane. The comparison of cartilaginous radii between humeral head and glenoid in different planes provides new information to understand the degree of conformity during abduction of the upper limb. METHODS: To investigate the radii, CT-images in soft-tissue kernel of 9 specimen were analysed using an image visualization software. Statistical analysis of the obtained data was performed using the t-test. RESULTS: Measurements of the radii in the glenoid revealed a significantly larger radius for bone than cartilage, whereas for the humeral head the opposite was the case. Highest ratios for cartilage in the transverse plane were found in the inferior and central areas of the joint surface, whereas the smallest ratios were found in the superior area. The radial mismatch varied between 0.1 mm and 13.6 mm, depending on the measured plane. CONCLUSIONS: The results suggest that in abduction, the cartilaginous guidance of the humeral head decreases. This might permit the humeral head an anterior-posterior shifting as well as superior-inferior translation. Surgical reconstruction of the normal glenohumeral relationships necessitates precise information about the glenohumeral morphology to ensure proper sizing and correct placement of prosthetic components and osteochondral allografts

CT-Osteoabsorptiometry (CT-OAM) - a new investigation technique in the field of mummy research

Introduction: The scientific study of mummies provides an insight into the life of past populations. Using CT-Osteoabsorptiometry (CT-OAM), a noninvasive technique based on conventional CT-data sets, it is possible to visualize the mineral density distribution in the subchondral bone plate, representing the long-term loading conditions of the articulation surface. The objective of the current study was to investigate the applicability of CT-OAM on mummies for the load analysis of joints as a new investigation technique in the field of mummy research. Material and methods: In order to clarify if apparent malpositions of the spinal column have existed during lifetime or occurred post-mortem, we evaluated the long-term loading patterns within the thoracic and lumbar endplates of 8 mummies. Results: The implementation of CT-OAM on mummies for load analysis of joints was feasible. The mineral density distribution within the endplates was not homogenous but followed distinct distribution patterns. In all of the endplates investigated the marginal zones were higher and the central areas lower mineralized, whereby the areas of greatest density were found in the peripheral marginal zones. The vertebra columns without malposition showed within the thoracic endplates an almost even circular allocation of the density maxima, whereas within the lumbar endplates an increased localization of the density maxima dorsomedial, dorsolateral and ventral was observed. The thoracic endplates of the spines with kyphosis did not show an even circular allocation anymore but a concentration of the density maxima in the ventral area and the endplates of the spines with scoliosis exhibited a predominant localization of the density maxima on the concave side. The examined endplates showed characteristic reproducible density patterns consistent with the long-term loading conditions. Conclusions: With help of CT-OAM pathological load distributions can be visualized before macroscopical changes appear and the information obtained can be useful to solve paleopathological and paleoarchaeological questions