The Glenoid Vault Outer Cortex a new more accurate radiological reference for shoulder arthroplasty

Introduction: Correct positioning of the glenoid component is an important determinant of outcome in shoulder arthroplasty. We describe and assess a new radiological plane of reference for improving the accuracy of glenoid preparation prior to component implantation – the Glenoid Vault Outer Cortex (GvOC) plane. Methods: One hundred and five CT scans of normal scapulae were obtained. Forty six females and 59 males aged between 22 and 30 years. The accuracy of the GvOC plane was then compared against the current “gold standard” – the scapular border (SB). Measurements of glenoid inclination, version, rotation, and offset were obtained using both the GvOC and SB planes. These were then compared to actual values. Results: The mean difference between version obtained using the GvOC plane and the actual value was 1.8° (−2 to 5, SD 1.6) as compared to 6.7° (−2 to 17, SD 4.3) when the SB plane was used, (p < 0.001). The mean difference between estimates of inclination obtained using the GvOC plane and the actual were 1.9° (−4 to 6, SD 1.6) as compared to 11.2° (−4 to 25, SD 6.1) when the SB plane was used, (p < 0.001). Conclusions: The GvOC plane produced estimates of glenoid version and inclination closer to actual values with lower variance than when the SB plane was used. The GvOC may be a more accurate and reproducible radiological method for surgeons to use when defining glenoid anatomy prior to arthroplasty surgery.

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Is the Glenoid Vault Outer Cortex a more Accurate Reference Plane than Conventional Methods in Shoulder Arthroplasty?

10.21203/rs.3.rs-93174/v1 ◽

2020 ◽

Author(s):

Thomas Gregory ◽

Simon Hurst ◽

Lorenzo Merlini ◽

Ulrich Hansen ◽

Jules Gregory ◽

...

Keyword(s):

Shoulder Arthroplasty ◽

Research Question ◽

Reference Value ◽

Mean Difference ◽

Reference Plane ◽

Glenoid Component ◽

Glenoid Version ◽

Outer Cortex ◽

Reproducible Method ◽

The Mean

Abstract Purpose Glenoid component positioning is an important determinant of outcome in anatomic shoulder arthroplasty. This is dependent on the accurate preparation of bony surfaces. We describe and assess a novel plane for improving the accuracy of bony preparation - the Glenoid Vault Outer Cortex plane (GvOC). Research question Does the GvOC plane provide a more accurate representation of glenoid version and inclination than the standard scapular border (SB) method ? Methods 105 CT scans of normal scapulae were obtained. 46 females and 59 males, aged between 22 to 30 years. Accuracy of the GvOC was compared against the current ‘gold standard’ – the SB method. Measurements of glenoid inclination, version, rotation, and offset were made using both GvOC and SB planes. These were compared to 'actual values' obtained using an alternative method. Results The mean difference between estimates of version based on the GvOC plane and the reference value were 1.8° (-2 to 5, SD 1.6) as compared to 6.7° (-2 to 17, SD 4.3) when the SB plane was used, (p<0.001). The mean difference between estimates of inclination based on the GvOC plane and the reference value were 1.9° (-4 to 6, SD 1.6) as compared to 11.2° (-4 to 25, SD 6.1) when the SB plane was used, (p<0.001). Conclusions The GvOC plane produced estimates of genoid version and inclination closer to the actual with a lower variance than using the standard SB plane. This may provide a more accurate and reproducible method for surgeons when defining native glenoid anatomy.

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The fulcrum axis: an accurate measure of glenoid version on radiographs and computed tomography

Shoulder & Elbow ◽

10.1177/1758573217728291 ◽

2017 ◽

Vol 11 (2) ◽

pp. 79-86

Author(s):

Jennifer Mutch ◽

Martin Sidler ◽

Claudia Sidler-Maier ◽

Terry Axelrod ◽

Diane Nam

Keyword(s):

Computed Tomography ◽

Shoulder Arthroplasty ◽

Gold Standard ◽

Total Shoulder Arthroplasty ◽

Three Dimensional ◽

Absolute Difference ◽

Single Institution ◽

Glenoid Version ◽

Rater Reliability ◽

The Mean

Background Proper glenoid position in total shoulder arthroplasty (TSA) is important. However, traditional glenoid version (GV) measurements overestimate retroversion on radiographs (XR) and computed tomography (CT). The fulcrum axis (FA) uses palpable surface landmarks and may be useful as an intra-operative guide. Also, the FA has not yet been validated on XR or CT in an arthritic population. Methods Four observers measured FA and GV on the XR, CT and three-dimensional CT (3DCT) of 40 patients who underwent TSA at a single institution from 2009 to 2015. Reliability and accuracy of FA and GV were calculated for XR and CT, using 3DCT as the gold standard. Results The mean FA and GV were 7.768° and 18.910° on XR; 6.23° and 12.920° on CT; and 8.100° and 7.740° on 3DCT, respectively. FA and GV were significantly different for XR and CT ( p < 0.001) but not for 3DCT ( p = 0.725). The inter-rater reliability, intra-rater reliability and accuracy of FA were not significantly different from GV and were 0.929 to 0.948, 0.779 to 0.974 and 0.674 to 0.705, respectively. However, the absolute difference of FA was closer to the gold standard (3DCT) than GV for XR (0.330° versus 11.172°) and CT (1.871° versus 5.178°) ( p < 0.001). Conclusions FA showed comparable reliability and accuracy to GV. However, FA more accurately reflected the gold standard.

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Optimal Screw Placement for Reverse Total Shoulder Arthroplasty

ASME 2010 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2010-19115 ◽

2010 ◽

Author(s):

Thuc-Quyen D. Nguyen ◽

James Guido DiStefano ◽

Andrew Y. Park ◽

Gerd Diederichs ◽

Jenni M. Buckley ◽

...

Keyword(s):

Bone Loss ◽

Shoulder Arthroplasty ◽

Total Shoulder Arthroplasty ◽

Glenoid Component ◽

Catastrophic Failure ◽

Bone Stock ◽

Common Causes ◽

Reverse Total Shoulder ◽

Arthroplasty Surgery ◽

Causes Of Failure

The reverse design of the total shoulder arthroplasty has been utilized for elderly patients with severely degenerated glenohumoral joints that are rotator cuff deficient. One of the most common causes of failure in shoulder arthroplasty involves loosening or catastrophic failure of the glenoid component. Such problems can be related to suboptimal fixation due to bone loss from fractures, severe degenerative changes and from previous failed arthroplasty surgery [1]. This emphasizes the need to secure the glenoid component with sound screw purchase beyond the glenoid vault. However, such fixation can often be tenuous as scapula bone quality is heterogeneous with a wide variation across short distances [2, 3]. Moreover, it can be difficult to identify regions with the best bone stock intraoperatively. This often requires multiple passes with the drill, which leads to further bone loss and potential decreased screw purchase. Thus, it is important for the surgeon to have a firm understanding of scapular anatomy with potential screw trajectories in mind.

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Validity assessment of a portable anthropometer to measure length in 24-month children from the 2015 Pelotas Birth Cohort

Public Health Nutrition ◽

10.1017/s136898002000107x ◽

2020 ◽

Vol 23 (15) ◽

pp. 2711-2716

Author(s):

Thaynã R Flores ◽

Andréa D Bertoldi ◽

Luiza IC Ricardo ◽

Cauane Blumenberg ◽

Laísa R Moreira ◽

...

Keyword(s):

Cohort Study ◽

Birth Cohort ◽

Gold Standard ◽

Mean Difference ◽

Birth Cohort Study ◽

Altman Plot ◽

Bland Altman Plot ◽

Validity Assessment ◽

The Mean

AbstractObjective:This study aimed to assess the validity of a portable anthropometer against the gold standard among 2-year-old infants from the 2015 Pelotas (Brazil) Birth Cohort.Design:Birth cohort study.Setting:A fixed Harpenden® infant anthropometer was considered as the gold standard for measuring infant length due to its greater precision and stability. The portable SANNY® (model ES2000) anthropometer was the instrument to be validated. The acceptable mean difference in length between the anthropometers was 0·5 cm. In order to compare length estimates, the interviewers carried out two length measures for each of the anthropometers (fixed and portable) and for each child. The mean of the two lengths was calculated for each anthropometer, and their difference was calculated.Participants:A subsample of 252 24-month-old members of the 2015 Pelotas (Brazil) birth cohort study.Results:Children’s mean age was 23·5 months. According to Bland–Altman plot, there were no differences in overall lengths between the portable and the fixed anthropometers, or in lengths according to sex. There was a high overall concordance between the length estimates of the fixed and portable anthropometers (ρ = 0·94; 95 % CI 0·92, 0·95).Conclusions:The portable anthropometer proved to be accurate to measure the length of 24-month-old infants, being applicable to studies using the same standardised protocol used in the present study.

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Accuracy and precision of a CT method for assessing migration in shoulder arthroplasty: an experimental study

Acta Radiologica ◽

10.1177/0284185119882659 ◽

2019 ◽

Vol 61 (6) ◽

pp. 776-782 ◽

Cited By ~ 2

Author(s):

Cyrus Brodén ◽

Joshua W Giles ◽

Ravi Popat ◽

Shirley Fetherston ◽

Henrik Olivecrona ◽

...

Keyword(s):

Effective Dose ◽

Shoulder Arthroplasty ◽

Gold Standard ◽

Total Shoulder Arthroplasty ◽

Glenoid Component ◽

Suitable Alternative ◽

Implant Migration ◽

System A ◽

Humeral Component ◽

Accuracy And Precision

Background Radiostereometric analysis (RSA) is the gold standard to measure early implant migration which is a predictive factor for implant survival. Purpose To validate an alternative computed tomography (CT) technique to measure implant migration in shoulder arthroplasty. Material and Methods A cadaver proximal humerus and a scapula, which had tantalum beads incorporated within them, were prepared to accept a short-stemmed humeral component and a two-pegged glenoid component of a commercial total shoulder arthroplasty (TSA) system. A five degree of freedom micrometer and goniometer equipped rig was used to translate and rotate the implant components relative to the respective bone to predetermined positions. Double CT examinations were performed for each position and CT motion analysis software (CTMA) was used to assess these movements. The accuracy and precision of the software was estimated using the rig’s micrometers and goniometers as the gold standard. The technique’s effective dose was also assessed. Results The accuracy was in the range of 0.07–0.23 mm in translation and 0.22–0.71° in rotation. The precision was in the range of 0.08–0.15 mm in translation and 0.23–0.54° in rotation. The mean effective dose for the CT scans was calculated to be 0.27 mSv. Conclusion In this experimental setting, accuracy, precision, and effective dose of the CTMA technique were found to be comparable to that of RSA. Therefore, we believe clinical studies are warranted to determine if CTMA is a suitable alternative to traditional RSA for migration measurements in TSA.

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Metacarpal Bony Dimensions Related to Headless Compression Screw Sizes

Journal of Hand and Microsurgery ◽

10.1055/s-0039-3400443 ◽

2019 ◽

Vol 12 (S 01) ◽

pp. S39-S44

Author(s):

Michael Okoli ◽

Kevin Lutsky ◽

Michael Rivlin ◽

Brian Katt ◽

Pedro Beredjiklian

Keyword(s):

Computed Tomography ◽

Fracture Fixation ◽

Ct Scans ◽

Compression Screw ◽

Metacarpal Head ◽

Headless Compression Screw ◽

Metacarpal Bones ◽

Headless Compression Screws ◽

The Mean ◽

Distal Aspect

Abstract Introduction The purpose of this study is to determine the radiographic dimensions of the finger metacarpals and to compare these measurements with headless compression screws commonly used for fracture fixation. Materials and Methods We analyzed computed tomography (CT) scans of the index, long, ring, and small metacarpal bones and measured the metacarpal length, distance from the isthmus to the metacarpal head, and intramedullary diameter of the isthmus. Metacarpals with previous fractures or hardware were excluded. We compared these dimensions with the size of several commercially available headless screws used for intramedullary fixation. Results A total of 223 metacarpals from 57 patients were analyzed. The index metacarpal was the longest, averaging 67.6 mm in length. The mean distance from the most distal aspect of the metacarpal head to the isthmus was 40.3, 39.5, 34.4, and 31 mm for the index, long, ring, and small metacarpals, respectively. The narrowest diameter of the isthmus was a mean of 2.6, 2.7, 2.3, and 3 mm for the index, long, ring, and small metacarpals, respectively. Of 33 commercially available screws, only 27% percent reached the isthmus of the index metacarpal followed by 42, 48, and 58% in the long, ring, and small metacarpals, respectively. Conclusion The index and long metacarpals are at a particular risk of screw mismatch given their relatively long lengths and narrow isthmus diameters.

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Do we need to improve the reporting of evidence in tendinopathy management? A critical appraisal of systematic reviews with recommendations on strength of evidence assessment

BMJ Open Sport & Exercise Medicine ◽

10.1136/bmjsem-2020-000920 ◽

2021 ◽

Vol 7 (1) ◽

pp. e000920

Author(s):

Dimitris Challoumas ◽

Neal L Millar

Keyword(s):

Systematic Reviews ◽

Assessment Tool ◽

Data Extraction ◽

Cochrane Collaboration ◽

Mean Difference ◽

Strength Of Evidence ◽

The Mean ◽

Randomised Controlled ◽

Meta Analyses ◽

The Cochrane Collaboration

ObjectiveTo critically appraise the quality of published systematic reviews (SRs) of randomised controlled trials (RCTs) in tendinopathy with regard to handling and reporting of results with special emphasis on strength of evidence assessment.Data sourcesMedline from inception to June 2020.Study eligibilityAll SRs of RCTs assessing the effectiveness of any intervention(s) on any location of tendinopathy.Data extraction and synthesisIncluded SRs were appraised with the use of a 12-item tool devised by the authors arising from the Preferred Reporting Items in Systematic Reviews and Meta-Analyses statement and other relevant guidance. Subgroup analyses were performed based on impact factor (IF) of publishing journals and date of publication.ResultsA total of 57 SRs were included published in 38 journals between 2006 and 2020. The most commonly used risk-of-bias (RoB) assessment tool and strength of evidence assessment tool were the Cochrane Collaboration RoB tool and the Cochrane Collaboration Back Review Group tool, respectively. The mean score on the appraisal tool was 46.5% (range 0%–100%). SRs published in higher IF journals (>4.7) were associated with a higher mean score than those in lower IF journals (mean difference 26.4%±8.8%, p=0.004). The mean score of the 10 most recently published SRs was similar to that of the first 10 published SRs (mean difference 8.3%±13.7%, p=0.54). Only 23 SRs (40%) used the results of their RoB assessment in data synthesis and more than half (n=30; 50%) did not assess the strength of evidence of their results. Only 12 SRs (21%) assessed their strength of evidence appropriately.ConclusionsIn light of the poor presentation of evidence identified by our review, we provide recommendations to increase transparency and reproducibility in future SRs.

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The Sankara Nethralaya Tamil Nadu Essilor Myopia (STEM) Study—Defining a Threshold for Non-Cycloplegic Myopia Prevalence in Children

Journal of Clinical Medicine ◽

10.3390/jcm10061215 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1215

Author(s):

Aparna Gopalakrishnan ◽

Jameel Rizwana Hussaindeen ◽

Viswanathan Sivaraman ◽

Meenakshi Swaminathan ◽

Yee Ling Wong ◽

...

Keyword(s):

Open Field ◽

Tamil Nadu ◽

Mean Difference ◽

School Vision ◽

Elite School ◽

Prevalence Estimates ◽

The Mean ◽

Clinically Significant ◽

Set Up ◽

Definition Of

The aim of this study was to investigate the agreement between cycloplegic and non-cycloplegic autorefraction with an open-field auto refractor in a school vision screening set up, and to define a threshold for myopia that agrees with the standard cycloplegic refraction threshold. The study was conducted as part of the Sankara Nethralaya Tamil Nadu Essilor Myopia (STEM) study, which investigated the prevalence, incidence, and risk factors for myopia among children in South India. Children from two schools aged 5 to 15 years, with no ocular abnormalities and whose parents gave informed consent for cycloplegic refraction were included in the study. All the children underwent visual acuity assessment (Pocket Vision Screener, Elite school of Optometry, India), followed by non-cycloplegic and cycloplegic (1% tropicamide) open-field autorefraction (Grand Seiko, WAM-5500). A total of 387 children were included in the study, of whom 201 were boys. The mean (SD) age of the children was 12.2 (±2.1) years. Overall, the mean difference between cycloplegic and non-cycloplegic spherical equivalent (SE) open-field autorefraction measures was 0.34 D (limits of agreement (LOA), 1.06 D to −0.38 D). For myopes, the mean difference between cycloplegic and non-cycloplegic SE was 0.13 D (LOA, 0.63D to −0.36D). The prevalence of myopia was 12% (95% CI, 8% to 15%) using the threshold of cycloplegic SE ≤ −0.50 D, and was 14% (95% CI, 11% to 17%) with SE ≤ −0.50 D using non-cycloplegic refraction. When myopia was defined as SE of ≤−0.75 D under non-cycloplegic conditions, there was no difference between cycloplegic and non-cycloplegic open-field autorefraction prevalence estimates (12%; 95% CI, 8% to 15%; p = 1.00). Overall, non-cycloplegic refraction underestimates hyperopia and overestimates myopia; but for subjects with myopia, this difference is minimal and not clinically significant. A threshold of SE ≤ −0.75 D agrees well for the estimation of myopia prevalence among children when using non-cycloplegic refraction and is comparable with the standard definition of cycloplegic myopic refraction of SE ≤ −0.50 D.

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Estimates of the mean difference in orthopaedic randomized trials: obligatory yet obscure

BMC Medical Research Methodology ◽

10.1186/s12874-021-01249-2 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Lauri Raittio ◽

Antti Launonen ◽

Ville M. Mattila ◽

Aleksi Reito

Keyword(s):

Primary Outcome ◽

Outcome Measure ◽

Patient Reported Outcome ◽

Ceiling Effect ◽

Mean Difference ◽

Discussion Section ◽

Power Calculations ◽

Randomized Controlled ◽

Patient Reported ◽

The Mean

Abstract Background Randomized controlled trials in orthopaedics are powered to mainly find large effect sizes. A possible discrepancy between the estimated and the real mean difference is a challenge for statistical inference based on p-values. We explored the justifications of the mean difference estimates used in power calculations. The assessment of distribution of observations in the primary outcome and the possibility of ceiling effects were also assessed. Methods Systematic review of the randomized controlled trials with power calculations in eight clinical orthopaedic journals published between 2016 and 2019. Trials with one continuous primary outcome and 1:1 allocation were eligible. Rationales and references for the mean difference estimate were recorded from the Methods sections. The possibility of ceiling effect was addressed by the assessment of the weighted mean and standard deviation of the primary outcome and its elaboration in the Discussion section of each RCT where available. Results 264 trials were included in this study. Of these, 108 (41 %) trials provided some rationale or reference for the mean difference estimate. The most common rationales or references for the estimate of mean difference were minimal clinical important difference (16 %), observational studies on the same subject (8 %) and the ‘clinical relevance’ of the authors (6 %). In a third of the trials, the weighted mean plus 1 standard deviation of the primary outcome reached over the best value in the patient-reported outcome measure scale, indicating the possibility of ceiling effect in the outcome. Conclusions The chosen mean difference estimates in power calculations are rarely properly justified in orthopaedic trials. In general, trials with a patient-reported outcome measure as the primary outcome do not assess or report the possibility of the ceiling effect in the primary outcome or elaborate further in the Discussion section.

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Corneal Biomechanical Parameters and Central Corneal Thickness in Glaucoma Patients, Glaucoma Suspects, and a Healthy Population

Journal of Clinical Medicine ◽

10.3390/jcm10122637 ◽

2021 ◽

Vol 10 (12) ◽

pp. 2637

Author(s):

Mª. Ángeles del Buey-Sayas ◽

Elena Lanchares-Sancho ◽

Pilar Campins-Falcó ◽

María Dolores Pinazo-Durán ◽

Cristina Peris-Martínez

Keyword(s):

Central Corneal Thickness ◽

Corneal Thickness ◽

Mean Difference ◽

The Other ◽

Control Group ◽

Healthy Population ◽

Diagnostic Categories ◽

Significant Difference ◽

Biomechanical Parameters ◽

The Mean

Purpose: To evaluate and compare corneal hysteresis (CH), corneal resistance factor (CRF), and central corneal thickness (CCT), measurements were taken between a healthy population (controls), patients diagnosed with glaucoma (DG), and glaucoma suspect patients due to ocular hypertension (OHT), family history of glaucoma (FHG), or glaucoma-like optic discs (GLD). Additionally, Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated IOP (IOPcc) were compared between the different groups of patients. Methods: In this prospective analytical-observational study, a total of 1065 patients (one eye of each) were recruited to undergo Ocular Response Analyzer (ORA) testing, ultrasound pachymetry, and clinical examination. Corneal biomechanical parameters (CH, CRF), CCT, IOPg, and IOPcc were measured in the control group (n = 574) and the other groups: DG (n = 147), FHG (n = 78), GLD (n = 90), and OHT (n = 176). We performed a variance analysis (ANOVA) for all the dependent variables according to the different diagnostic categories with multiple comparisons to identify the differences between the diagnostic categories, deeming p < 0.05 as statistically significant. Results: The mean CH in the DG group (9.69 mmHg) was significantly lower compared to controls (10.75 mmHg; mean difference 1.05, p < 0.001), FHG (10.70 mmHg; mean difference 1.00, p < 0.05), GLD (10.63 mmHg; mean difference 0.93, p < 0.05) and OHT (10.54 mmHg; mean difference 0.84, p < 0.05). No glaucoma suspects (FHG, GLD, OHT groups) presented significant differences between themselves and the control group (p = 1.00). No statistically significant differences were found in the mean CRF between DG (11.18 mmHg) and the control group (10.75 mmHg; mean difference 0.42, p = 0.40). The FHG and OHT groups showed significantly higher mean CRF values (12.32 and 12.41 mmHg, respectively) than the DG group (11.18 mmHg), with mean differences of 1.13 (p < 0.05) and 1.22 (p < 0.001), respectively. No statistically significant differences were found in CCT in the analysis between DG (562 μ) and the other groups (control = 556 μ, FHG = 576 μ, GLD = 569 μ, OHT = 570 μ). The means of IOPg and IOPcc values were higher in the DG patient and suspect groups than in the control group, with statistically significant differences in all groups (p < 0.001). Conclusion: This study presents corneal biomechanical values (CH, CRF), CCT, IOPg, and IOPcc for diagnosed glaucoma patients, three suspected glaucoma groups, and a healthy population, using the ORA. Mean CH values were markedly lower in the DG group (diagnosed with glaucoma damage) compared to the other groups. No significant difference was found in CCT between the DG and control groups. Unexpectedly, CRF showed higher values in all groups than in the control group, but the difference was only statistically significant in the suspect groups (FHG, GLD, and OHT), not in the DG group.

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