Expression of Chondrogenic Potential Markers in Cultured Chondrocytes from the Human Knee Joint.

OBJECTIVES: While substantial progress has been made in engineering cartilaginous constructs for animal models, further research is needed to translate these methodologies for human applications. Evidence suggests that cultured autologous chondrocytes undergo changes in phenotype and gene expression, thereby affecting their proliferation and differentiation capacity. This study was designed to evaluate the expression of chondrogenic markers in cultured human articular chondrocytes from passages 3 (P3) and 7 (P7), beyond the current clinical recommendation of P3. METHODS: Cultured autologous chondrocytes were passaged from P3 up to P7, and quantitative polymerase chain reaction (qPCR) was used to assess mRNA expression of chondrogenic markers, including collagen type I (COLI), collagen type II (COLII), aggrecan (AGG), bone morphogenetic protein 4 (BMP4), transcription factor SOX-9 (SOX9), proteoglycan 4 (PGR4), and transformation-related protein 53 (p53), between P3 and P7. RESULTS: Except for AGG, no significant differences were found in the expression of markers between passages, suggesting the maintenance of chondrogenic potential in cultured chondrocytes. Differential expression identified between SOX9 and PGR4, as well as between COLI and SOX9, indicates that differences in chondrogenic markers are present between age groups and sexes, respectively. CONCLUSIONS: Overall, expression profiles of younger and male chondrocytes exhibit conversion of mature cartilage characteristics compared to their counterparts, with signs of dedifferentiation and loss of phenotype within-group passaging. These results may have implications in guiding the use of higher passaged chondrocytes for engineering constructs and provide a foundation for clinical recommendations surrounding the repair and treatment of articular cartilage pathology in both sexes.

Exploring the use of rating scales with entrustment anchors in workplace-based assessment.

PURPOSE: Competency-based medical education (CBME) has prompted widespread implementation of workplace-based assessment (WBA) tools using entrustment anchors. This study aimed to identify factors that influence faculty's rating choices immediately following assessment and explore their experiences using WBAs with entrustment anchors, specifically the Ottawa Surgical Competency Operating Room Evaluation scale. METHOD: A convenience sample of 50 semi-structured interviews with Emergency Medicine (EM) physicians from a single Canadian hospital were conducted between July and August 2019. All interviews occurred within two hours of faculty completing a WBA of a trainee. Faculty were asked what they considered when rating the trainee's performance and whether they considered an alternate rating. Two team members independently analysed interview transcripts using conventional content analysis with line-by-line coding to identify themes. RESULTS: Interviews captured interactions between 70% (26/37) of full-time EM faculty and 86% (19/22) of EM trainees. Faculty most commonly identified the amount of guidance the trainee required as influencing their rating. Other variables such as clinical context, trainee experience, past experiences with the trainee, perceived competence and confidence were also identified. While most faculty did not struggle to assign ratings, some had difficulty interpreting the language of entrustment anchors, being unsure whether their assessment should be retrospective or prospective in nature, and if/how the assessment should change whether they were 'in the room' or not. CONCLUSIONS: By going to the frontline during WBA encounters, this study captured authentic and honest reflections from physicians immediately engaged in assessment using entrustment anchors. While many of the factors identified are consistent with previous retrospective work, we highlight how some faculty consider factors outside the prescribed approach and struggle with the language of entrustment anchors. These results further our understanding of 'in-the-moment' assessments using entrustment anchors and may facilitate effective faculty development regarding WBA in CBME.

Sacro-Iliac Joint Sensory Block and Radiofrequency Ablation: Assessment of Bony Landmarks Relevant for Image-Guided Procedures.

Image-guided sensory block and radiofrequency ablation of the nerves innervating the sacro-iliac joint require readily identifiable bony landmarks for accurate needle/electrode placement. Understanding the relative locations of the transverse sacral tubercles along the lateral sacral crest is important for ultrasound guidance, as they demarcate the position of the posterior sacral network (S1-S3 ± L5/S4) innervating the posterior sacro-iliac joint. No studies were found that investigated the spatial relationships of these bony landmarks. The purpose of this study was to visualize and quantify the interrelationships of the transverse sacral tubercles and posterior sacral foramina to inform image-guided block and radiofrequency ablation of the sacro-iliac joint. The posterior and lateral surfaces of 30 dry sacra (15 M/15 F) were digitized and modeled in 3D and the distances between bony landmarks quantified. The relationships of bony landmarks (S1-S4) were not uniform. The mean intertubercular and interforaminal distances decreased from S1 to S4, whereas the distance from the lateral margin of the posterior sacral foramina to the transverse sacral tubercles increased from S1 to S3. The mean intertubercular distance from S1 to S3 was significantly (p < 0.05) larger in males. The interrelationships of the sacral bony landmarks should be taken into consideration when estimating the site and length of an image-guided strip lesion targeting the posterior sacral network.