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. 2021 Mar 17;14(5):491–499. doi: 10.1177/17585732211001756

Anatomical plane and transverse axis of the scapula: Reliability of manual positioning of the anatomical landmarks

Adrien Jacquot 1,2,✉, Marc-Olivier Gauci 3, Manuel Urvoy 4, François Boux de Casson 5, Julien Berhouet 6,7, Hoel Letissier 8,9
PMCID: PMC9527481  PMID: 36199507

Abstract

Background

The aim of our study was to evaluate the accuracy of manual determination of the three key points defining the anatomical plane of the scapula, which conditions the reliability of planning software programs based on manual method.

Method

We included 82 scapula computed tomography scans (56 pathologic and 26 normal glenoid), excluding truncation and major three-dimensional artifact. Four observers independently picked the three key points for each case. Inter- and intra-observer agreement was calculated for each point, using the intraclass correlation method. The mean error (mm) between the observers was calculated as the diameter of the smallest sphere including the four chosen positions.

Results

Lower inter-observer agreement was found for the trigonum superoinferior position and for the glenoid center anteroposterior position. The mean positioning error between the four observers was 6.9 mm for the trigonum point, and error greater than 10 mm was recorded in 25% of the cases. The mean positioning error was 3.5 mm for the glenoid center in altered glenoid, compared to 1.8 mm for normal glenoid.

Discussion

Manual determination of an anatomical plane of the scapula suffers from inaccuracy especially due to the variability in trigonum picking, and in a lesser extent, to the variability of glenoid center picking in altered glenoid.

Keywords: Scapula, glenoid, pre-operative planning, shoulder arthroplasty, glenoid orientation, scapular plane

Introduction

Background

In the field of shoulder arthroplasty, computer-assisted surgery has grown significantly over the last decade, including three-dimensional (3D) preoperative planning, patient specific instrumentation, and intraoperative navigation.1–9 The aim of these systems is to help surgeons optimize their preoperative plan and intraoperative implant positioning. To achieve 3D preoperative planning, an accurate and reliable evaluation of glenoid orientation (version and inclination) is mandatory.10,11 These parameters influence both the choice of the prosthesis (anatomic or reversed) and the implant position, in order to optimize shoulder function and long-term survivorship. 10

Rationale

Standard X-rays are not accurate enough for glenoid morphology assessment. 12 Friedman et al. described the classic method for glenoid version measurement on a 2D computed tomography (CT) scan, using the standard axial slice at the level of the tip of the coracoid. 13 However, it has been demonstrated that version values can vary significantly with this technique, because of the gantry angle, meaning the sagittal and coronal rotation of the scapula relative to the patient’s position on the CT-scan table.14,15 As a consequence, 3D-reformatting imaging is now recognized as necessary to provide reliable measures.16–22 Anatomical plane of the scapula is often used in the literature as the reference plane to perform 3D glenoid measures,16,19,21,22 avoiding variability due to the patient and scapula position. The anatomical plane is defined manually by three points as described by Kwon et al.: the center of the glenoid, the trigonum, and the inferior angle of the scapula. 21 In the same way, the trigonum and the glenoid center (GC) are also used to generate the transverse axis that represents the reference for inclination measurement. 21 Consequently, version, inclination, and humeral head subluxation measures seem highly related to the precision of the picking of those three points. However, to our knowledge, no analysis of the accuracy of the manual positioning of the three points has been published yet.

Study purpose

The aim of the study was to evaluate the accuracy and reliability of manual positioning of the three key points defining the anatomical plane of the scapula and transverse axis, both on normal and pathologic shoulders.

Methods

Study setting and population

Our study was approved by the Institutional Review Board of the ethical committee of the IULS (Nice, France – Study 2017-10). This study was based on CT scans of both normal and pathologic scapulae, extracted from our local anonymized database of normal and pathologic scapulae. For each case of this database, age, sex, etiology, and glenoid classification were known. Exclusion criteria were scapulae with any kind of medial or inferior truncation as well as scapulae with a 3D artifact around the picking zones (glenoid, trigonum, or inferior angle). We performed a prior power analysis (parameters: mean positioning error = 5 mm, standard deviation = 10 mm, α = 5% and β = 20%), which indicated that the minimum number of cases needed was 63. From our reference database, we randomly selected a population of 86 scapulae (26 normal and 60 pathologic). We secondarily excluded three scapulae with medial or inferior truncation and one scapula with major 3D artifact of the scapula body including the trigonum. Finally, 82 scapula were analyzed (56 pathologic and 26 normal). The etiologies for the pathologic glenoid as well as Walch23,24 and Favard 25 classifications are detailed in Table 1. Among this population, we defined two groups according to the glenoid deformity: Low Deformity Glenoid group (n = 46: normal scapula, Walch A1, B1, and Favard E0, E1 glenoid) and Altered Glenoid group (n = 36: post-traumatic arthropathy with glenoid involvement, instability arthropathy, rheumatoid arthritis, Walch A2, B2, B3, C, D and Favard E2, E3, E4 glenoid). There were 26 males and 56 females, and the mean age was 61 years ± 17 (range: 15–87).

Table 1.

Pathologic glenoid distribution according to Walch or Favard classifications.

Pathology Classification Population – N (%)
PGHOA Walch 31
A1 5
A2 6
B1 2
B2 10
B3 6
C 1
D 1
CTA/MRCT Favard 16
E0 5
E1 5
E2 2
E3 4
PTA 4
IA 2
RA 2
AON 1
Other etiologies – 9
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PGHOA: primary gleno-humeral osteoarthritis; CTA: cuff tear arthropathy; MRCT: massive rotator cuff tear; PTA: post-traumatic arthropathy; IA: instability arthropathy; RA: rheumatoid arthritis; AVN: aseptic osteonecrosis.

Experimental protocol

All the CT-scan images were acquired in a supine position, using the following protocol: 120 to 140 kV, 240 mA, pitch ≤0.9, rotation time ≤1 s and maximum 1.2 mm slice increment. Field of view had to include the entire scapula, without truncation. Images were stored in DICOM files, which were analyzed in a dedicated homemade software program (PickingApp 1.3, Imascap [MU], Figure 1), enabling 2D and 3D visualization of the scapular body. The software was developed for sequential picking of defined points of interest on the 3D structure of the scapula. Four independent observers (AJ, MOG, JB, and HL), who were all experienced shoulder surgeons and highly involved in 3D imaging-assisted surgery, performed a manual picking of three points on each of the 82 scapulae: the GC (Figure 2(a)), the trigonum scapulae (TS), and the inferior angle (IA). TS was defined as the most medial point of the scapula, located in the area where the scapular spine joins the medial edge (Figure 3(a) to (c)). IA was defined as the most inferior point of the scapular body (Figure 4(a)). GC, TS, and IA defined the anatomical plane of the scapula according to Kwon et al. 21 GC and TS defined the scapular transverse axis. Prior training was carried out to clearly define the position of each key point and to harmonize the picking between the four observers. One of the observers (AJ) did the manual picking a second time two months later for evaluation of the intra-observer reliability.

Figure 1.

Figure 1.

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Homemade software for 3D picking of the scapular key points. The software enabled 2D and 3D visualization, and free mobilization of the 3D model, in order to pick precisely the three key points on the scapular body: glenoid center, trigonum scapulae, and inferior angle.

Figure 2.

Figure 2.

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Position of the glenoid center (picked points in red). (a) Normal glenoid. Easy determination of the glenoid center. (b) Altered glenoid, with hazardous determination of the center.

Figure 3.

Figure 3.

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Position of the trigonum scapulae (picked points in red). (a) Trigonum scapulae is located in the junction area between the scapular spine and the medial border of the scapula. (b) Visible angulation of the medial border of the scapula, whose tip is the most medial point of the scapula, and corresponds to the position of the trigonum scapulae. (c) Trigonum scapulae is located where the superior part of the scapular spine crosses the medial border of the scapula. (c, e, and f) Variable morphology of the medial border of the scapula, leading to possible mispositioning (superoinferior). (d) Curved medial border without visible angulation. e. Straight medial border without visible angulation. (f) Truncation of the superior part of the scapular body, making exact localization difficult.

Figure 4.

Figure 4.

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Position of the inferior angle (picked points in red). (a) Inferior angle defined as the most distal point of the scapular body. (b) Flat inferior angle leading to possible mispositioning (medio-lateral).

Data processing

The coordinates of the three key points of the scapular plane (GC, TS, and IA) were then recorded in a coordinate system, for each of the four observers, and for the 82 scapulae. The origin of the system was positioned at the barycenter of the scapula to be at an equivalent distance from each of the three key points and reproducible from one case to another. Intraclass correlation (ICC) was calculated for the three key points to assess the inter-observer agreement of the four observers (ICC-inter), as well as the intra-observer agreement for one of the observers (ICC-intra). Because the position of the center of the coordinate system implies variability in ICC results, the mean positioning error (mm) between the four observers was represented by the diameter of the smallest sphere including the 4 chosen positions (bounding sphere, Figure 5), for each of the three key points. We also compared the bounding sphere diameters for the GC according to the type of glenoid (pathologic or not). We finally conducted a formal outlier analysis to make sure outliers were not always picked by the same observer and were not caused by technical errors.

Figure 5.

Figure 5.

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Bounding spheres representing the picking accuracy of the four observers. For each of the three key points, we determined the smallest sphere including the four points picked by the four observers.

Statistical analysis

The results were presented in terms of mean ± standard deviation (range). Two-way mixed-effects ICC models (ICC [2,1]) were used to determine absolute agreement. ICCs were calculated to analyze inter- and intra-rater reliability using the method described by Shrout et al. 26 The Student t test was used to compare quantitative variables between groups. Multiple means comparisons were realized using one-way analysis of variance with Tukey post hoc test. Alpha risk was set to 5%. A p value less than or equal to .05 was considered significant. The statistical analysis was realized using MedCalc Statistical Software version 18.2.1 (MedCalc Software Bvba).

Results

ICCs for each of the three key points are presented in Table 2. Lower inter- and intra-observer agreements were found for the TS positioning along the superoinferior axis (0.76 and 0.91, respectively) and for the GC positioning along the anteroposterior axis (0.85 and 0.82, respectively).

Table 2.

Intra-class correlation for the three key points: inter-observer (four observers) and intra-observer agreement.

ICC-inter
 ICC-intra
antero-posterior Supero-inferior Medio-lateral Global antero-posterior Supero-inferior Medio-lateral Global
Inferior angle 0.95 (0.93–0.97) 0.995 (0.993–0.997) 0.97 (0.96–0.98) 0.999 (0.998–0.999) 0.96 (0.94–0.97) 0.999 (0.999–1) 0.99 (0.98–0.99) 0.999 (0.999–1)
Trigonum 0.91 (0.87–0.94) 0.76 (0.63–0.84) 0.989 (0.984–0.992) 0.995 (0.993–0.996) 0.98 (0.96–0.99) 0.91 (0.81–0.95) 0.99 (0.985–0.996) 0.998 (0.997–0.999)
Glenoid center 0.85 (0.80–0.89) 0.99 (0.985–0.995) 0.995 (0.992–0.996) 0.998 (0.998–0.999) 0.82 (0.73–0.88) 0.996 (0.99–1) 0.99 (0.98–0.99) 0.998 (0.998–0.999)
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ICC: intra-class correlation. ICC values are considered good, even at 0.76, and p values were never significant. This is explained by the chosen position of the center of the system. The interesting point here is the comparative analysis, showing only 2 values <0.9, different from 0.99 or 0.98 obtained for most of the locations.

The average error of positioning and the mean bounding sphere diameter for each of the three key points are presented in Table 3. The bounding sphere diameter was significantly higher for TS (6.9 ± 6.8 mm; range: 0.9–26) than for the two other key points (both p < 0.0001). For TS, the bounding sphere diameter was over 10 mm for 20 cases (24.4%), mostly because of a superoinferior mispositioning (mean 6.3 ± 6.4 mm; range: 0–24). All the bounding spheres but one had a < 10 mm diameter for GC and IA. There was no significant difference in the bounding sphere diameter between GC and IA (p = 0.89). The main positioning error for GC was anteroposterior (2 ± 1.6 mm; range: 0.9–26), whereas for IA, the main error was mediolateral (2.2 ± 1.9 mm; range: 0–8). The outlier analysis showed that outliers were homogeneously distributed between the four observers and that none of them could be explained by a technical problem.

Table 3.

Positioning error for the three key points (four observers).

Mean error of positioning – three axis (mm)
 Sphere Diameter
Antero- posterior Supero- inferior Medio- lateral Mean (mm) ± std (range) Sphere diameter >5 mm (N) Sphere diameter >10 mm (N)
Inferior angle 1 ± 0.7 (0–4) 0.8 ± 0.8 (0–3) 2.2 ± 1.9 (0–8) 2.8 ± 1.9 (0.7–9) 12 0
Trigonum 2.2 ± 2.4 (0–11) 6.3 ± 6.4 (0–24) 0.9 ± 1 (0–6) 6.9 ± 6.8 (0.9–26) 34 20
Glenoid center 2 ± 1.6 (0–11) 1.1 ± 1.1 (0–5) 0.5 ± 1 (0–8) 2.5 ± 1.8 (0.5–13) 7 1
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Regarding GC, the mean diameter of the bounding sphere was 1.8 ± 0.6 mm (range: 0–3) in the Low Deformity Glenoid group, whereas the mean diameter was 3.5 ± 2.4 mm (range: 0.8–13) for the Altered Glenoid Group, and the difference was significant (p < 0.001) (Figure 2).

Discussion

Our study demonstrated that manual determination of the scapular plane by manual picking of three key points on the scapular body is not perfectly accurate and reproducible, especially regarding TS positioning along the superoinferior axis, as well as the anteroposterior position of GC in case of a pathologic glenoid. This could lead to variability in glenoid orientation measurement when these key points are used as inputs for calculations.

Inter- and intra-observer variability was evaluated by calculation of the ICC for each of the three key points. All the ICCs were over 0.75, which is usually considered excellent. 27 However, in the case of our study, we did not compare means but 3D positions in a coordinate system. Indeed, as the distance from the system’s origin increases, the discrepancies between the observers’ choices are under-evaluated. In fact, the more distant the system’s origin (barycenter of the scapula) is from the key points, the better the ICC will be. Thus, the relevance of absolute results was questionable, and we assumed that interpretation of the ICC results should rather be relative and comparative. Regarding the obtained values (Table 2), the lower ICC found for TS superoinferior position, as well as for the GC anteroposterior position, allowed us to consider the positioning of these two points inaccurate. This was confirmed by the analysis of the bounding sphere diameters, showing average errors of 6.9 mm for TS, and 3.5 mm for the GC in case of altered glenoid. Beyond the average error, analysis of the outliers is mandatory because it reflects the proportion of cases in which the degree of error is not acceptable in clinical practice. Regarding TS, an error of more than 10 mm (up to 26 mm) was observed in almost 25% of the cases.

The lowest inter-observer agreement was found for the superoinferior position of TS. This was explained by a variable morphology of the medial edge of the scapula (Figure 3(d) to (f)), which often makes it difficult to determine the exact position of this point, especially its height. Superoinferior variation of TS position might not significantly influence the orientation of the scapular plane because the direction of the error is almost collinear with the plane. Thus, it might not alter reliability of glenoid version measurement, in accordance with the results reported by Kwon et al. 21 and others.18–20,22 However, it might induce a variation of the orientation of the scapular transverse axis (axis between the GC and TS), which is used for glenoid inclination calculation. This is a concern for the reliability of inclination measurement, regarding the 25% of reported outliers in our series (>10 mm error). Inclination outliers reported by Denard et al. 28 when comparing manual and automatic software (19% of errors greater than 10°) could be explained by this variability of TS positioning with the manual method. GC mispositioning mainly occurred along the anteroposterior axis, which could influence the scapular plane orientation and thus the glenoid version measurement. Average error was only 2.5 mm, and error over 10 mm was only observed in one case, which might not be relevant; however, the mean error was significantly higher (3.5 mm) for altered glenoid, which are practically the most frequent situation for preoperative planning. Chalmers et al. 29 reported significantly different version values with manual and automatic methods, possibly explained by the difficulty of positioning GC on altered glenoid with the manual method. IA positioning errors were slight, and mainly mediolateral, which could also be explained as well by a variable morphology of this area (Figure 4(b)). As the direction of the error is almost collinear with the plane, this might have a low influence on scapular plane orientation and thus on glenoid measures. The lack of reliability of TS and GC positioning was observed both in inter- and intra-observer analysis, meaning that it is not only explained by possible variable interpretations of the defined position from an observer to another.

Kwon et al., 21 who initially described the 3D manual method based on the scapular plane, reported excellent inter-observer agreement for glenoid version measurement, but on the basis of only 12 normal glenoid, and without evaluation of glenoid inclination. Other authors also reported excellent inter- and intra-observer agreement for glenoid version measurement using a manual three-point-based scapular plane as a reference.18–20,22 Only Lewis et al. 22 evaluated both version and inclination measurements with this method, on 20 healthy scapulae, and also found excellent ICCs for both measurements. Based on these results, the manual technique for 3D glenoid assessment is currently considered the gold standard. But to our knowledge, reliability of the manual positioning of the key points defining scapula plane et transverse axis has never been specifically evaluated. More recently, fully automated software programs have been proposed, performing automatic processing of scapula 3D reconstruction and glenoid measurements, without human participation. The body plane of the scapula – different from the classic anatomical plane – is determined automatically using thousands of voxels and a mathematical least-square method, rather than only three points placed freehand. Reliability of this automatic technique has been previously reported.30–32 However, some authors reported a comparison between manual and automatic software programs, and differences were observed in the obtained measurements. This was arbitrary attributed to a lack of accuracy of the automatic software, the manual technique being the gold standard. Chalmers et al. 29 reported comparable inclination but significantly different version values between an automatic software and the manual corrected-Friedman method, in a population of B2 glenoid, and assumed this might be related to inaccurate automatic measurements. Similarly, Denard et al. 28 found differences in version and inclination measurements between a manual method and an automatic software program. In 57% of the cases, either version or inclination varied by 5° or greater, and in 24% of the cases by 10° or greater. They hypothesized that the observed differences were mainly explained by segmentation problems on the glenoid side with the automatic software. Reliability of manual determination of the anatomical plane of the scapula was not evaluated in these studies. In a recent study, Boileau et al. 17 showed that fully automated software was accurate and reliable, with excellent correlation in the performed measurements. They argued that it is also time saving, and independent from the surgeon’s experience in the anatomical landmarks position, avoiding variability in measurements and unintended outliers. Our study confirmed that manual methods could lead to some accidental variability of the anatomical landmarks position, inducing potential error in glenoid orientation measurements. This could explain, at least in part, the reported errors between manual and automatic methods,28,29 and invalidate the gold-standard status of manual methods. In fact, if the manual positioning of the key-points is inaccurate, then the reference scapula plane and transverse axis used in the manual method may not be reliable, and this could have serious consequences on the values of glenoid orientation obtained with this method, and therefore negatively influence the pre-operative planning, regarding selection and positioning of the implants.

This article was limited to the analysis of the reliability the manual positioning of the three key points and did not assess the consequences in terms of version and inclination measurements. This could be considered a limitation of our study. In fact, for legibility reasons, we preferred to separate those two analysis, as the methodologies were very different. The analysis of version and inclination variation, when using different reference planes and transverse axis, will be the subject of a further publication.

Conclusions

This study suggests that manual determination of the three key points defining the scapular plane and transverse axis is not reliable, especially for the TS, but also for the GC in altered glenoid to a lesser extent. This could have consequences for the reliability of glenoid orientation measurements, when using traditional manual techniques for 3D preoperative planning, and thus negatively influence both the implant selection, and the planned position of the prosthesis.

Footnotes

Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Dr. Adrien JACQUOT is consultant for Tornier-Wright Medical and receives consulting fees. Dr. Marc-Olivier GAUCI is consultant for Tornier-Wright Medical and receives consulting fees. Manuel URVOY is an Employee of Imascap (Wright Medical). François BOUX DE CASSON is an Employee of Tornier – Wright Medical. Dr. Julien BERHOUET is consultant for Tornier-Wright Medical, and receives consulting fees. Dr. Hoel LETISSIER has no conflict of interest.

Funding: The author(s) received no financial support for the research, authorship, and/or publication of this article.

Ethical Review: The institutional review board of the ethical committee of the IULS (Nice, France) approved this study (Study 2017-10).

Contributorship

Adrien Jacquot: Observer (picking), Study design, data analysis, and paper writing.

Marc-Olivier Gauci: Observer (picking), study design, and paper review.

Manuel Urvoy: Software development.

François Boux de Casson: Study design, data analysis and consulting, and paper review.

Julien Berhouet: Observer (picking) and paper review.

Hoel Letisser: Observer (picking), data analysis and statistics, and paper review.

ORCID iDs

Adrien Jacquot https://orcid.org/0000-0003-1315-7894

Marc-Olivier Gauci https://orcid.org/0000-0003-2228-7084

Hoel Letissier https://orcid.org/0000-0001-7289-5243

References

  • 1.Kircher J, Wiedemann M, Magosch P ; et al. Improved accuracy of glenoid positioning in total shoulder arthroplasty with intraoperative navigation: a prospective-randomized clinical study. J Shoulder Elbow Surg 2009; 18: 515–520. [DOI] [PubMed] [Google Scholar]
  • 2.Nashikkar PS, Scholes CJ, Haber MD. Computer navigation re-creates planned glenoid placement and reduces correction variability in total shoulder arthroplasty: an in vivo case-control study. J Shoulder Elbow Surg 2019; 28: e398–e409. [DOI] [PubMed] [Google Scholar]
  • 3.Nguyen D, Ferreira LM, Brownhill JR ; et al. Improved accuracy of computer assisted glenoid implantation in total shoulder arthroplasty: an in-vitro randomized controlled trial. J Shoulder Elbow Surg 2009; 18: 907–914. [DOI] [PubMed] [Google Scholar]
  • 4.Verborgt O, De Smedt T, Vanhees M ; et al. Accuracy of placement of the glenoid component in reversed shoulder arthroplasty with and without navigation. J Shoulder Elbow Surg 2011; 20: 21–26. [DOI] [PubMed] [Google Scholar]
  • 5.Iannotti JP, Walker K, Rodriguez E ; et al. Accuracy of 3-dimensional planning, implant templating, and patient-specific instrumentation in anatomic total shoulder arthroplasty. J Bone Joint Surg Am 2019; 101: 446–457. [DOI] [PubMed] [Google Scholar]
  • 6.Jacquot A, Gauci M-O, Chaoui J ; et al. Proper benefit of a three dimensional pre-operative planning software for glenoid component positioning in total shoulder arthroplasty. Int Orthop 2018; 42: 2897–2906. [DOI] [PubMed] [Google Scholar]
  • 7.Verborgt O, Hachem AI, Eid K ; et al. Accuracy of patient-specific guided implantation of the glenoid component in reversed shoulder arthroplasty. Orthop Traumatol Surg Res 2018; 104: 767–772. [DOI] [PubMed] [Google Scholar]
  • 8.Suero EM, Citak M, Lo D ; et al. Use of a custom alignment guide to improve glenoid component position in total shoulder arthroplasty. Knee Surg Sports Traumatol Arthrosc 2013; 21: 2860–2866. [DOI] [PubMed] [Google Scholar]
  • 9.Dallalana RJ, McMahon RA, East B ; et al. Accuracy of patient-specific instrumentation in anatomic and reverse total shoulder arthroplasty. Int J Shoulder Surg 2016; 10: 59–66. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Farron A, Terrier A, Büchler P. Risks of loosening of a prosthetic glenoid implanted in retroversion. J Shoulder Elbow Surg 2006; 15: 521–526. [DOI] [PubMed] [Google Scholar]
  • 11.Shapiro TA, McGarry MH, Gupta R ; et al. Biomechanical effects of glenoid retroversion in total shoulder arthroplasty. J Shoulder Elbow Surg 2007; 16: S90–S95. [DOI] [PubMed] [Google Scholar]
  • 12.Nyffeler RW, Jost B, Pfirrmann CWA ; et al. Measurement of glenoid version: conventional radiographs versus computed tomography scans. J Shoulder Elbow Surg 2003; 12: 493–496. [DOI] [PubMed] [Google Scholar]
  • 13.Friedman RJ, Hawthorne KB, Genez BM. The use of computerized tomography in the measurement of glenoid version. J Bone Joint Surg Am 1992; 74: 1032–1037. [PubMed] [Google Scholar]
  • 14.Bryce CD, Davison AC, Lewis GS ; et al. Two-dimensional glenoid version measurements vary with coronal and sagittal scapular rotation. J Bone Joint Surg Am 2010; 92: 692–699. [DOI] [PubMed] [Google Scholar]
  • 15.Bokor DJ, O’Sullivan MD, Hazan GJ. Variability of measurement of glenoid version on computed tomography scan. J Shoulder Elbow Surg 1999; 8: 595–598. [DOI] [PubMed] [Google Scholar]
  • 16.Budge MD, Lewis GS, Schaefer E ; et al. Comparison of standard two-dimensional and three-dimensional corrected glenoid version measurements. J Shoulder Elbow Surg 2011; 20: 577–583. [DOI] [PubMed] [Google Scholar]
  • 17.Boileau P, Cheval D, Gauci M-O ; et al. Automated three-dimensional measurement of glenoid version and inclination in arthritic shoulders. J Bone Joint Surg 2018; 100: 57–65. [DOI] [PubMed] [Google Scholar]
  • 18.De Wilde LF, Verstraeten T, Speeckaert W ; et al. Reliability of the glenoid plane. J Shoulder Elbow Surg 2010; 19: 414–422. [DOI] [PubMed] [Google Scholar]
  • 19.Hoenecke HR, Hermida JC, Flores-Hernandez C ; et al. Accuracy of CT-based measurements of glenoid version for total shoulder arthroplasty. J Shoulder Elbow Surg 2010; 19: 166–171. [DOI] [PubMed] [Google Scholar]
  • 20.Matsumura N, Ogawa K, Kobayashi S ; et al. Morphologic features of humeral head and glenoid version in the normal glenohumeral joint. J Shoulder Elbow Surg 2014; 23: 1724–1730. [DOI] [PubMed] [Google Scholar]
  • 21.Kwon YW, Powell KA, Yum JK ; et al. Use of three-dimensional computed tomography for the analysis of the glenoid anatomy. J Shoulder Elbow Surg 2005; 14: 85–90. [DOI] [PubMed] [Google Scholar]
  • 22.Lewis GS, Armstrong AD. Glenoid spherical orientation and version. J Shoulder Elbow Surg 2011; 20: 3–11. [DOI] [PubMed] [Google Scholar]
  • 23.Walch G, Badet R, Boulahia A ; et al. Morphologic study of the glenoid in primary glenohumeral osteoarthritis. J Arthroplasty 1999; 14: 756–760. [DOI] [PubMed] [Google Scholar]
  • 24.Bercik MJ, Kruse K, Yalizis M ; et al. A modification to the Walch classification of the glenoid in primary glenohumeral osteoarthritis using three-dimensional imaging. J Shoulder Elbow Surg 2016; 25: 1601–1606. [DOI] [PubMed] [Google Scholar]
  • 25.Favard L, Lautmann S, Sirveaux F; et al. Hemiarthroplasty versus reverse arthroplasty in the treatment of osteoarthritis with massive rotator cuff tear. In: Walch G, Boileau P, Mole D. (eds). 2000 Shoulder prostheses. Two to ten years follow-up, Paris: Sauramps Médical, 2001, pp. 261–268. [Google Scholar]
  • 26.Shrout PE, Fleiss JL. Intraclass correlations: uses in assessing rater reliability. Psychol Bull 1979; 86: 420–428. [DOI] [PubMed] [Google Scholar]
  • 27.Cohen J. Statistical power analysis for the behavioral sciences. New York, NY: Academic Press.
  • 28.Denard PJ, Provencher MT, Lädermann A ; et al. Version and inclination obtained with 3-dimensional planning in total shoulder arthroplasty: do different programs produce the same results? JSES Open Access 2018; 2: 200–204. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29.Chalmers PN, Salazar D, Chamberlain A ; et al. Radiographic characterization of the B2 glenoid: is inclusion of the entirety of the scapula necessary? J Shoulder Elbow Surg 2017; 26: 855–860. [DOI] [PubMed] [Google Scholar]
  • 30.Moineau G, Levigne C, Boileau P ; et al. Three-dimensional measurement method of arthritic glenoid cavity morphology: feasibility and reproducibility. Orthop Traumatol Surg Res 2012; 98: S139–S145. [DOI] [PubMed] [Google Scholar]
  • 31.Walch G, Vezeridis PS, Boileau P ; et al. Three-dimensional planning and use of patient-specific guides improve glenoid component position: an in vitro study. J Shoulder Elbow Surg 2015; 24: 302–309. [DOI] [PubMed] [Google Scholar]
  • 32.Walch G, Mesiha M, Boileau P ; et al. Three-dimensional assessment of the dimensions of the osteoarthritic glenoid. Bone Joint J 2013; 95-B: 1377–1382. [DOI] [PubMed] [Google Scholar]

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