Widening Access: Sterile Tourniquets for Surgery to the Distal Humerus.

Purpose of the study The use of tourniquets during surgery of the distal humerus can improve visibility and reduce surgical time. However, the available operating field can be limited due to the size and placement of the tourniquet. This proof-of-concept study aimed to determine if sterile tourniquets can provide a wider surgical field compared to non-sterile tourniquets for procedures around the distal humerus. Methods Volunteers (n = 5) were positioned to simulate access to the distal humerus. The distance from the posterior corner of the acromion to the tip of the olecranon was measured. Participants were draped according to the standard protocol for the use of a non-sterile or sterile tourniquet for distal humerus and humeral shaft fractures. Two non-sterile pneumatic tourniquets (standard and narrow) and two sterile tourniquets (pneumatic and elastic exsanguination) were tested. The surgical field was measured from the sterile drape or tourniquet proximally to the tip of the olecranon. A one-way repeated measures ANOVA was conducted to examine the effect of each tourniquet on the surgical field. Results The sterile elastic exsanguination tourniquet had the largest available field with a mean of 24.4 cm (71% of arm available for incision after application), followed by the sterile pneumatic tourniquet of 20.0 cm (58%), narrow non-sterile pneumatic of 19.2 cm (55%), and standard non-sterile pneumatic of 17.0 cm (49%). Repeated measures ANOVA determined that mean surgical field length is statistically significant between tourniquet devices (F (1.729, 6.914) = 21.783, p = .001). The surgical field length was statistically significantly increased from a non-sterile standard tourniquet to a sterile elastic tourniquet (7.4 (95% CI, 2.9-11.9) cm, p = .008) but not the other two tourniquet devices tested. Conclusion The use of certain types of sterile tourniquets can provide a wider surgical field compared to non-sterile tourniquets for procedures around the distal humerus, specifically the sterile elastic exsanguination tourniquet providing a statistically significant mean gain of 7.4 cm from the non-sterile tourniquets. These findings suggest that the use of sterile tourniquets should be considered more frequently in surgery of the distal humerus, and a sterile exsanguinating tourniquet could be considered for midshaft humeral fractures, facilitating safer exposure of the radial nerve and reduced blood loss.

Effectiveness of early versus delayed rehabilitation following total shoulder replacement: A systematic review.

OBJECTIVE: To investigate the effectiveness of early versus delayed rehabilitation following total shoulder replacement. DESIGN: Intervention systematic review with narrative synthesis. LITERATURE SEARCH: MEDLINE, EMBASE, CINAHL, Scopus and the Cochrane Library were searched from inception to the 29th of July 2021. STUDY SELECTION CRITERIA: Randomised controlled trials comparing early versus delayed rehabilitation following primary anatomic, primary reverse, or revision total shoulder replacement. DATA SYNTHESIS: A revised Cochrane risk of bias assessment tool for randomised controlled trials was used, as well as the Grading of Recommendations Assessment, Development and Evaluation approach to evaluate the quality of evidence. A narrative synthesis was undertaken. RESULTS: Three eligible randomised controlled trials (n = 230) were included. There was very low-quality evidence of no statistically significant difference (P > 0.05) in pain, shoulder function, health-related quality of life or lesser tuberosity osteotomy healing at 12 months between early or delayed rehabilitation. There was conflicting and very low-quality evidence of a difference between the effect of early and delayed rehabilitation on shoulder range of movement. There was limited, very low-quality evidence of statistically significantly improved pain and function (P < 0.05) in the early post-operative period with early rehabilitation following anatomic total shoulder replacement. CONCLUSIONS: No differences were seen in patient-reported or clinician-reported outcomes at 12 months post-surgery between early and delayed rehabilitation following total shoulder replacement. There is very low-quality evidence that early rehabilitation may improve shoulder pain and function in the early post-operative phase following anatomic total shoulder replacement.

Wide-Awake Shoulder Nanoscopic Long Head of Biceps Tenotomy.

Arthroscopic long head of biceps tenotomy is an established technique for addressing shoulder pain associated with long head of biceps pathology. Arthroscopic techniques, compared with open surgery, have demonstrated improvements in outcomes for patients including rapid recovery, but either regional or general anesthesia is required, which is associated with complications. We describe a novel technique using a Nanoscope needle arthroscopy system that allows for long head of biceps tenotomy to be performed under local anesthetic in the outpatient or office setting.

Rehabilitation following shoulder arthroplasty in the United Kingdom National Health Service: A survey of publicly facing information.

INTRODUCTION: The prevalence of shoulder arthroplasty (SA) is rising, but there is limited research evaluating rehabilitation following SA and whether there is an optimal approach remains unknown. The aim of this study was to understand current National Health Service (NHS) practice for rehabilitation following SA as a platform for conducting much needed further research. METHODS: Two reviewers independently undertook electronic searches for publicly available information sheets (PIS) from websites of NHS Trusts that included detail about rehabilitation following SA, for example, duration of immobilisation. One reviewer extracted data, and a second reviewer verified this. ETHICAL APPROVAL: Not required. RESULTS: Forty-three PIS from 40 Trusts were identified. Twenty-four referred to more than one type of arthroplasty (anatomic, reverse and hemiarthroplasty) but did not describe different approaches to rehabilitation based on prosthesis type. Twenty-five PIS provided some instruction regarding movement restrictions, which varied considerably. All PIS referred to postoperative immobilisation, typically with a sling, with median duration of 4 weeks (range 0 to 8). Thirty-four PIS reported commencing passive exercise immediately. Median time to commencing active exercise was 4 weeks (range 1 to 6) and 5 weeks (range 1 to 16) for resisted exercise. Median time expected to return to driving was 6 weeks (range 3 to 12) and general work 12 weeks (range 3 to 26). CONCLUSION: This study has highlighted significant heterogeneity between rehabilitation approaches following SA, not previously reported in the United Kingdom, with a lack of specific rehabilitation PIS for different prosthesis types. Our results will facilitate evaluation of rehabilitation strategies in future research.

Evaluation of primary care 6- to 8-week hip check for diagnosis of developmental dysplasia of the hip: a 15-year observational cohort study.

BACKGROUND: The current 6- to 8-week Newborn and Infant Physical Examination (NIPE) clinical assessment is a current standard hip-screening test in the community (England) to detect developmental dysplasia of the hip (DDH). AIM: To assess the value of the primary care 6- to 8-week clinical hip examination for the diagnosis of DDH. DESIGN AND SETTING: A single-centre 15-year observational cohort study at a district general hospital between 1 January 1996 and 31 December 2010. METHOD: Those referred by the GP or community practitioner with suspected instability or abnormality of the hip joint (DDH), were clinically and sonographically examined in a specialist hip-screening clinic. Modified Graf Type III and IV, and radiological irreducible hip dislocation were considered to be 'pathological' hips. Screening failures were defined as those who had not been identified by this primary care screening assessment (but had irreducible hip dislocation). Secondary univariate and multivariable analyses were performed to determine which clinical findings are predictive of instability. RESULTS: Over the study period, there were 70 071 infants who underwent the 6- to 8-week clinical hip assessment. In the specialist hip-screening clinic, six (from the 170 referred) were diagnosed with pathological DDH. The sensitivity, specificity, positive predictive value, and negative predictive value for the 6- to 8-week clinical hip assessment were 16.7%, 99.8%, 3.5%, and 100.0%, respectively. A multivariable model showed a positive Ortolani manoeuvre to be the sole independent predictor of instability at 6 to 8 weeks. CONCLUSION: This 15-year study highlights the limitations of a hip check at 6 to 8 weeks. These findings support the reassessment of the national guidelines for this aspect of the NIPE DDH screening programme.

Development and Evaluation of a New Formative Assessment of Surgical Performance.

BACKGROUND: Formative assessment of operative performance is a mandatory part of surgical training. Engagement with assessment is limited in part by the time-consuming nature and the high perceived stakes of current assessment tools. OBJECTIVES: Our aims were to develop and collect validity evidence for a new operative assessment tool that addresses barriers to assessment that current trainers and trainees experience. METHODS: We developed the Generic Operative Supervised Learning Event (GOSLE). Orthopedic trainees were invited to complete GOSLEs with their trainers after surgical procedures. Experienced consultants assessed videotaped operations performed by trainees using the GOSLE. Validity evidence for content, relationships to other scores, internal structure, response process, and consequences of testing were evaluated. RESULTS: A total of 250 GOSLEs were completed. A strong correlation was found between the GOSLE scores and the Procedure-Based Assessment ratings (r = 0.87, p < 0.001). Rasch analysis confirmed satisfactory internal structure of the rating scale, with sequential increases in rating as performance improved. The reproducibility coefficient was 0.88, with 10 assessments of the same trainee who has to achieve a reliability coefficient of 0.8. Over 90% of users found the GOSLE easy to use, with most preferring it to other assessment methods. Feedback quality was higher using the GOSLE than with current assessments. CONCLUSION: We have collected validity evidence across multiple domains in support of the GOSLE. Its psychometric performance is comparable to that of current assessments. It is preferred by trainers and trainees over existing assessments. It stimulates high-quality, actionable feedback which better supports formative assessment. By addressing issues experienced with existing assessments, we expect engagement among users to be high.

A decision tool for whole-body CT in major trauma that safely reduces unnecessary scanning and associated radiation risks: An initial exploratory analysis.

BACKGROUND: Whole-body CT (WBCT) has become routine practice in the assessment of major trauma patients. Whilst this may be associated with increased survival, several studies report high rates of negative scans. As no national guideline exists, selection criteria for WBCT vary widely. This study aims to (1) produce a scoring system that improves patient selection for WBCT (2) quantify patient radiation doses and their concomitant risk of malignancy. METHODS: Clinical notes were reviewed for all patients undergoing a WBCT for trauma over a 21-month period at a UK major trauma centre. Clinical and radiological findings were categorised according to body region. Univariate analysis was performed using Chi-squared testing, followed by multivariable logistic regression. Secondary regression analysis of patients with significant injuries that the model did not identify was performed. The model was optimised and used to develop a scoring system. Sensitivity and specificity were calculated using the same dataset as was used to derive the models. Radiation exposure was determined and the excess lifetime risk of malignancy calculated. RESULTS: 255 patients were included, with a mean age of 45 years. 16% of scans were positive for polytrauma, 42% demonstrated some injury and 42% showed no injury. The regression model identified independent predictors of polytrauma to be (1) clinical signs in more than one body region, (2) reduced Glasgow Coma Score, (3) haemodynamic abnormality, (4) respiratory abnormality, (5) mechanism of injury. The final model had a sensitivity of 95% (95% CI 86-99%) and specificity of 59% (95% CI 52-66%) for significant CT findings. Mean radiation exposure was 31.8 mSv, conferring a median excess malignancy risk of 1 in 474. CONCLUSION: After including neurological deficit, our scoring system had a sensitivity of 97% (95% CI 88-99%) and specificity of 56% (95% CI 49-64%) for significant injury. We propose this is used to stratify the use of trauma radiographs, focused CT and WBCT for major trauma patients. Although not intended to replace clinical judgement, our scoring system adds an objective component to decision-making. We believe this will safely reduce the number of unnecessary CT scans performed on a relatively young cohort of patients.

Methyl vinyl ketone--identification and quantification of adducts to N-terminal valine in human hemoglobin.

Adducts to N-terminal valines in Hb have been shown useful as biomarkers of exposure to electrophilic compounds. Adducts from many compounds have earlier been measured with a modified Edman degradation method using a GC-MS/MS method. A recently developed method, the adduct FIRE procedure™, adopted for analysis by LC-MS/MS, has been applied in this study. With this method a fluorescein isothiocyanate (FITC) reagent is used to measure adducts (R) from electrophiles with a modified Edman procedure. By using LC-MS/MS in product ion scan mode, a new peak was identified and the obtained MS data indicated that this adduct could originate from methyl vinyl ketone (MVK). Incubation of human-, sheep- and bovine blood with MVK increased the signal of the identified peak. By comparing the LC-MS/MS data from the unknown background peak with data obtained from synthesized fluorescein thiohydantoin (FTH) standards of the MVK adduct to valine and d(8)-valine, the identity of this adduct was confirmed. The MVK adduct was shown present in human blood (∼35 pmol/g globin, n=3) and only just above LOD in bovine blood, n=1 (LOD=2 pmol/g globin). MVK reacts, in similarity with acrylamide, via Michael addition. MVK is known to occur in the environment and has earlier been observed in biological samples, which means that there are possible natural and anthropogenic exposure sources. Analysis of an Hb adduct from MVK in humans has to our knowledge not been described before.

Evaluation of molecularly imprinted solid-phase extraction for a 1,2:3,4-diepoxybutane adduct to valine.

A molecularly imprinted polymer, MIP, was prepared and evaluated as SPE sorbent for a cyclicized adduct formed to N-terminal valine (Pyr-Val) in hemoglobin from 1,2:3,4-diepoxybutane (DEB). This metabolite plays an important role in the carcinogenesis of 1,3-butadiene. The hydrazide of Pyr-Val, formed after hydrazinolysis of hemoglobin, as well as necessary standards was synthesized. The MIP was prepared from methacrylic acid with a structure analogue to the investigated adduct as template and the method was developed for aqueous conditions. Selective desorption was achieved when the sample was washed with water after loading in 10% acetonitrile. The primary interaction with the binding sites in the imprints was most likely of ionic character. Quantification of the Pyr-Val adduct was performed with LC/ESI-MS/MS, yielding an instrumental LOD of 150 pg injected amount.

A new general pathway for synthesis of reference compounds of N-terminal valine-isocyanate adducts.

Adducts to Hb could be used as biomarkers to monitor exposure to isocyanates. Particularly useful is the measurement of carbamoylation of N-terminal valines in Hb, after detachment as hydantoins. The synthesis of references from the reactive isocyanates, especially diisocyanates, has been problematic due to side reactions and polymerization of the isocyanate starting material. A simpler, safer, and more general method for the synthesis of valine adducts of isocyanates has been developed using N-[(4-nitrophenyl)carbamate]valine methylamide (NPCVMA) as the key precursor to adducts of various mono- and diisocyanates of interest. By reacting NPCVMA with a range of isocyanate-related amines, carbamoylated valines are formed without the use of the reactive isocyanates. The carbamoylated products synthesized here were cyclized with good yields of the formed hydantoins. The carbamoylated derivative from phenyl isocyanate also showed quantitative yield in a test with cyclization under the conditions used in blood. This new pathway for the preparation of N-carbamoylated model compounds overcomes the above-mentioned problems in the synthesis and is a general and simplified approach, which could make such reference compounds of adducts to N-terminal valine from isocyanates accessible for biomonitoring purposes. The synthesized hydantoins corresponding to adducts from isocyanic acid, methyl isocyanate, phenyl isocyanate, and 2,6-toluene diisocyanate were characterized by LC-MS analysis. The background level of the hydantoin from isocyanic acid in human blood was analyzed with the LC-MS conditions developed.

Measurement of time-dependent changes in the irregularity of neural spiking.

Irregularity of firing in spike trains has been associated with coding processes and information transfer or alternatively treated as noise. Previous studies of irregularity have mainly used the coefficient of variation (CV) of the interspike interval distribution. Proper estimation of CV requires a constant underlying firing rate, a condition that most experimental situations do not fulfill either within or across trials. Here we introduce a novel irregularity metric based on the ratio of adjacent intervals in the spike train. The new metric is not affected by firing rate and is very localized in time so that it can be used to examine the time course of irregularity relative to an alignment marker. We characterized properties of the new metric with simulated spike trains of known characteristics and then applied it to data recorded from 108 single neurons in the motor cortex of two monkeys during performance of a precision grip task. Fifty-six cells were antidromically identified as pyramidal tract neurons (PTNs). Sixty-one cells (30 PTNs) exhibited significant temporal modulation of their irregularity during task performance with the contralateral hand. The irregularity modulations generally differed in sign and latency from the modulations of firing rate. High irregularity tended to occur during the task phases requiring the most detailed control of movement, whereas neural firing became more regular during the steady hold phase. Such irregularity modulation could have important consequences for the response of downstream neurons and may provide insight into the nature of the cortical code.