The role of the immune microenvironment in bone, cartilage, and soft tissue regeneration: from mechanism to therapeutic opportunity

Bone, cartilage, and soft tissue regeneration is a complex spatiotemporal process recruiting a variety of cell types, whose activity and interplay must be precisely mediated for effective healing post-injury. Although extensive strides have been made in the understanding of the immune microenvironment processes governing bone, cartilage, and soft tissue regeneration, effective clinical translation of these mechanisms remains a challenge. Regulation of the immune microenvironment is increasingly becoming a favorable target for bone, cartilage, and soft tissue regeneration; therefore, an in-depth understanding of the communication between immune cells and functional tissue cells would be valuable. Herein, we review the regulatory role of the immune microenvironment in the promotion and maintenance of stem cell states in the context of bone, cartilage, and soft tissue repair and regeneration. We discuss the roles of various immune cell subsets in bone, cartilage, and soft tissue repair and regeneration processes and introduce novel strategies, for example, biomaterial-targeting of immune cell activity, aimed at regulating healing. Understanding the mechanisms of the crosstalk between the immune microenvironment and regeneration pathways may shed light on new therapeutic opportunities for enhancing bone, cartilage, and soft tissue regeneration through regulation of the immune microenvironment.

Optimisation of imaging parameters during CT guided interventional procedures in patients with total hip arthroplasty

Objective

To determine the optimal KV and mAs settings during CT guided injections in the presence of a total hip arthroplasty so that image quality is maintained whist keeping the dose as low as reasonably achievable.

Methods

A total hip arthroplasty phantom with needles with differing gauges was scanned using different CT parameters (from low dose to high dose) and evaluating if this had any effect on needle conspicuity. Conspicuity was graded from 1 to 3 by 2 independent blinded reviewers.

Results

Irrespective of the CT settings used (high dose or low dose parameters) needle conspicuity was not adversely affected by the THA for either scorer, therefore a kVp of 100 mA and a. In addition the needle gauge did not affect the conspicuity of the needle.

Conclusion

CT guided injections in this total hip arthroplasty phantom model can be performed without any adverse effect on the conspicuity of the needle tip on low dose CT settings.

Advancement in knowledge

This paper enables one to optimise the kV and mA while performing interventional procedures.

National audit of non-melanoma skin cancer excisions performed by plastic surgery in the UK

A national, multi-centre audit of non-melanoma skin cancer excisions by plastic surgery.

The learning curve and safety of continuous intraoperative vagus nerve monitoring in thyroid surgery

INTRODUCTION

Continuous intraoperative nerve monitoring allows for continuous feedback on the integrity of the recurrent laryngeal nerve (RLN) and the quality of its induced myogenic potential. The aims of this study were to assess the time requirements and risks associated with vagus nerve electrode placement when learning the technique.

METHODS

This is a prospective observational study carried out in a single otolaryngology department at the start of a trainee's placement. A total of 40 vagus nerve dissections in 31 consecutive operations (22 hemithyroidectomies, 9 total thyroidectomies) using automatic periodic stimulation (APS, Medtronic) are included. Of the electrode placements, 10 were performed by the trainer and 30 by the trainee. The time required for each surgical step and complications relating to vagus nerve dissection were recorded.

RESULTS

The average (median+IQR) total additional time attributable to vagus nerve dissection, electrode placement and baseline electromyogenic assessment was 3.1mins (2.5-3.3) for the trainer and 4.8mins (4.1-5.3) for the trainee (p<0.0001). There was a downward trend in time requirement for the trainee (not statistically significant, p=0.080). Total operative time was 38min (35-45) for hemithyroidectomy and 56min (53-62) for total thyroidectomy. There was a mix of benign (74%) and malignant (26%) histology, no intraoperative complications relating to autonomic dysfunction and one (2.5%) transient nerve palsy.

CONCLUSIONS

Operative time attributable to vagus nerve electrode placement is short and the procedure is easy to learn. Appropriate surgical technique and careful anaesthetic considerations allow monitoring to be performed safely, and may reduce the rate of RLN palsy.

Fusion product measurements by nuclear diagnostics in the Joint European Torus deuterium-tritium 2 campaign (invited)

A new deuterium-tritium experimental, DTE2, campaign has been conducted at the Joint European Torus (JET) between August 2021 and late December 2021. Motivated by significant enhancements in the past decade at JET, such as the ITER-like wall and enhanced auxiliary heating power, the campaign achieved a new fusion energy world record and performed a broad range of fundamental experiments to inform ITER physics scenarios and operations. New capabilities in the area of fusion product measurements by nuclear diagnostics were available as a result of a decade long enhancement program. These have been tested for the first time in DTE2 and a concise overview is provided here. Confined alpha particle measurements by gamma-ray spectroscopy were successfully demonstrated, albeit with limitations at neutron rates higher than some 10¹⁷ n/s. High resolution neutron spectroscopy measurements with the magnetic proton recoil instrument were complemented by novel data from a set of synthetic diamond detectors, which enabled studies of the supra-thermal contributions to the neutron emission. In the area of escaping fast ion diagnostics, a lost fast ion detector and a set of Faraday cups made it possible to determine information on the velocity space and poloidal distribution of the lost alpha particles for the first time. This extensive set of data provides unique information for fundamental physics studies and validation of the numerical models, which are key to inform the physics and scenarios of ITER.

571 Evaluating the Effectiveness of Extracorporeal Shockwave Lithotripsy (ESWL) for Ureteric Stones During COVID-19 Pandemic - A Single Centre Experience

Aim

Reliance on ESWL for treating ureteric stone has increased during the COVID-19 pandemic. We examined the outcomes for ureteric stones treated with our on-site lithotripter to assess the success rate and determine the variables that could affect the outcome results.

Method

A retrospective review using electronic records and images of patients who underwent ESWL for ureteric stones (January to December 2020). Univariate and multivariate analysis used to determine stone-free rate predictors (Stone Free rate/SFR: No residual stones on post-ESWL imagining).

Results

A total of 36 patients underwent ESWL for ureteric stones. Mean age was 58 years (21–90), and mean stone size was 8 mm (5–20). Stones were located in the proximal (67%) or lower ureter (33%). Overall SFR was 64% (67% proximal, 33% distal). 64% of patients required only one session to be stone free, with 60% stone free after two sessions. Stones <10mm had a SFR of 67%, compared to 58% for stone >10 mm. The only statistically significant predictor was stone size (longest dimension, p=0.04). No statistical significance with stone location (P=0.09), skin-to-stone distance (SSD) (P=0.7), stone density (P=0.3) or stone volume (P=0.3). In treatment failure, time to definitive ureteroscopy was 4 weeks.

Conclusion

Our overall SFR was slightly lower than expected but comparable to available literature. This data highlights the importance of patient selection for ESWL and would be useful in counselling about local success rate. More than half of the patients required only one session for stone clearance and stone size was the only significant predictor for successful ESWL.

The influence of site on the incidence and diagnosis of solitary central cartilage tumours of the femur. A 21st century perspective

OBJECTIVE

To determine the incidence of central cartilage tumours (CCTs) in the femur and the impact of site (proximal, mid and distal thirds) on tumour grade. To compare study results with historically published data.

MATERIALS AND METHODS

Retrospective review of solitary CCTs arising in the femur over the past 13 years. Data collected included location (proximal, mid and distal thirds) and final diagnosis in terms of tumour grade based on imaging features ± histology. Case material collected from three bone tumour textbooks provided historical data.

RESULTS

430 solitary CCTs were included in the femur. 73% cases arose in the distal, 3.7% in the mid and 23% in the proximal femur. The ratio of "benign" (combining enchondroma and atypical cartilaginous tumour (ACT)) to higher grade chondrosarcoma (CS) was 11:1 in the distal, 1:1 in the mid and 1:1.5 in the proximal femur, the distribution of benign to malignant tumours being significantly different between the regions (F test, p < 0.05). Comparison with historical data showed a reversal of the benign (enchondroma) to malignant (ACT and higher grade CS) of 30%:70%-84%:16% in the current series.

CONCLUSIONS

The site of origin of a CCT in the femur has an impact on final diagnosis with CS uncommon in the distal as compared with the mid and proximal femur. This is in contradistinction to historical data where the incidence of CS exceeded that of enchondroma at all sites.

O003 Radiation-related chromosomal aberrations observed in high volume endovascular operators performing X-ray guided surgery

Introduction

The biological effects of chronic, low dose radiation, to which operators performing fluoroscopy-guided procedures are exposed, are unknown. We have previously demonstrated acute DNA damage/repair in lymphocytes from operators performing fluoroscopy-guided endovascular aneurysm repair (EVAR), but these markers normalised after 24 hours and did not inform on the residual accumulated effects of chronic radiation exposure. In the present study cytogenetic techniques were used to examine for chromosomal aberrations in endovascular operators.

Methods

Peripheral blood lymphocytes were isolated from high volume endovascular operators performing EVAR and age-matched radiation naïve general surgeons as controls. Giemsa staining was used to visualise the full complement of chromosomes and all dicentrics, where 2 centromeres are present in a single chromosome, were identified. The genome was analysed for abnormal exchanges of genetic material between chromosomes using multiplex fluorescence in situ hybridisation (mFISH).

Results

Lymphocytes from 18 operators (12 exposed, 6 controls) were analysed. A higher frequency of dicentric chromosomes were found in exposed operators compared with controls (0.0011 vs 0.0004, respectively, P=0.002) after examining 54,000 lymphocytes. Twice as many complex chromosome rearrangements were seen in endovascular operators compared with controls (0.48% vs 0.24%). Aneuploidy, the abnormal loss of chromosomes, was more frequent in endovascular operators with a median difference of 0.35 per chromosome (P=0.004).

Conclusion

We have found a higher frequency of chromosomal aberrations in endovascular operators compared with radiation naïve colleagues. This justifies further individual biological profiling for genomic instability and personalised radiation risk assessment.

Take-home message

Radiation-related DNA damage occurs in endovascular operators despite current radiation protection measures. Biological dosimetry could be a useful tool, allowing personalised risk assessment.

O099 Position and number of anchors in hip arthroscopy labrum repair: a systematic review

Introduction

Hip labral tears are reported in 22–55% of patients with hip or groin pain. Operative treatment is necessary for most cases, via hip arthroscopy with the use of suture anchors. This systematic review aims to determine the optimal number and position of anchors in hip labral repair.

Methods

Pubmed, Ovid & Embase were searched, and 2 researchers independently screened the 1,304 results. Outcome measures such as procedures performed, number & (clockface) position of anchors, failure & articular involvement of anchors were extracted.

Results

5 studies were included in the analysis: 1 Cross-Sectional Study (1645 Hips, mean age (MA):33.7 years), 3 Retrospective case studies (491 hips, MA:31.0) and 1 Controlled Cadaveric study (32 cadaveric hips, MA:62.7). Chi-squared statistical analysis of 323 hips found a significant difference (X2 (2, N = 323) = 17.88, p &lt; .001) in the risk of articular involvement with the position of anchors at 11°-12° o’clock, 1°-2° and 3°-4°. There is an absolute risk reduction (ARR) of 19% with anchors positioned at 11°-12° compared to anchors positioned at 3°-4° (X2 (1, N=178) =15.79, p &lt; .001) and an ARR of 12% with anchors at 1°-2° compared to anchors positioned at 3°-4° (X2 (1, N = 237) = 15.79, p &lt; .0109). Additionally, by assessing 1645 operations it was found that for tears spanning &gt;2 hours, a minimum of 2 anchors was placed.

Conclusion

Placement of anchors in the 3°-4° o’clock position carries the highest risk for articular involvement. Small diameter anchors and careful placement can be used to minimize articular injury. Preferable positions of anchors are 11°-12°, furthermore, for tears spanning over 2 hours, a minimum of 2 anchors was placed.

Take-home message

In Hip Arthroscopy labral repair, placement of anchors in the 3°-4° o’clock position carries the highest risk for articular involvement. Small diameter anchors and 2 hours. flexible anchor instrumentation can be used to minimize articular injury, furthermore, for tears spanning over 2 hours, a minimum of 2 anchors was placed.

Endoscopic ultrasound-guided portal pressure gradient with liver biopsy: 6 years of endo-hepatology in practice

BACKGROUND AND AIM

The portal pressure gradient (PPG) is a useful predictor of portal hypertension (PH) related complications. We previously showed the feasibility and safety of endoscopic ultrasound guided PPG measurement (EUS-PPG). Now EUS-guided liver biopsy (EUS-bx) has been shown to be a safe and effective alternative to percutaneous or Interventional Radiology-guided liver biopsy for the diagnosis of chronic liver disease (CLD). We aimed to evaluate the correlation between PPG and clinical markers of PH, and assess the feasibility and safety of concomitant, single session EUS-PPG and EUS-bx.

METHODS

This was a retrospective study of patients undergoing EUS-PPG for CLD at a single tertiary endoscopy center between February 2014 and March 2020. EUS-PPG was performed using a 25-gauge needle and compact manometer. Data analysis was performed with SAS version 9.4.

RESULTS

Eighty-three patients underwent EUS-PPG with 100% technical success. The mean PPG was 7.06 mmHg (SD 6.09, range 0-27.3). PPG was higher in patients with (vs without) clinical features of cirrhosis (9.46 vs 3.61 mmHg, P < 0.0001), esophageal or gastric varices (13.88 vs 4.34 mmHg, P < 0.0001), and thrombocytopenia (9.25 vs 4.71 mmHg, P = 0.0022). In the 71 patients (85.5%) who underwent EUS-bx, 70 (98.6%) specimens were deemed adequate by the pathologist for histologic diagnosis. There were no early or late major adverse events.

CONCLUSION

EUS-PPG correlates well with clinical markers of PH. EUS-bx can be performed safely during the same session as EUS-PPG, providing a comprehensive endoscopic evaluation of the patient with CLD.

Comparison of Clinical, Biochemical, and Histopathologic Profiles between NAFLD in Asian-Indians and United States Adults

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is very common in both Asian and Western countries. Geographic variation leads to differences in epidemiological and demographic characters of NAFLD patients. Studies conducted upon different ethnic groups in the United States (US) show a higher prevalence of NAFLD in Hispanics and African-Americans. There is however, a paucity of studies involving Asians. It has been observed that Asian-Indian NAFLD patients have unique characteristics compared to their counterparts in the West. This study is the first attempt at comparing the characteristics of Asian-Indian and US NAFLD patients.

MATERIALS AND METHODS

A retrospective analysis of clinical, biochemical, and histological data was performed for 633 Asian-Indian NAFLD patients and 451 US NAFLD patients. Clinical parameters [age, gender, body mass index (BMI), diabetes, hypertension, etc.], biochemical tests (liver function tests, lipid profile, and fasting blood sugar), hepatic ultrasound and hepatic histology were compared between the two cohorts.

RESULTS

Eighty-two percent of US NAFLD patients were more than 40 years of age compared to 51.3% of Asian-Indian patients (p <0.01). US (male 56.3%) and Asian-Indian (male 81.7%) (p <0.01) patients differed from each other as regards gender prevalence. Rates of obesity were greater in the US patients compared to Asian-Indians (BMI 32.6 ± 5.3 kg/m2 vs 26.2 ± 3.4 kg/m2). There was a higher prevalence of both diabetes and hypertension (diabetes 42.1% vs 33%, and hypertension 56.8% vs 29.7%, p ≤0.01) in US patients. ALT levels were also significantly higher in US NAFLD patients compared to Asian-Indians (ALT 82.78 ± 71.30 vs 53.66 ± 37, p ≤0.01). A higher proportion of US patients were found to have the more advanced liver disease at the time of diagnosis compared to Asian-Indians (Stage 3 fibrosis 10.42% vs 0%, and Stage 4 fibrosis 2.66% vs 0%, p <0.01).

CONCLUSION

Asian-Indian and US NAFLD patients differ significantly on several parameters. Further studies need to be carried out to understand the mechanistic basis of these differences better.

HOW TO CITE THIS ARTICLE

Singh SP, Panigrahi MK, Patel A, et al. Comparison of Clinical, Biochemical, and Histopathologic Profiles between NAFLD in Asian-Indians and United States Adults. Euroasian J Hepato-Gastroenterol 2022;12(Suppl 1):S15-S18.