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

2017 ◽  
Vol 11 (2) ◽  
pp. 79-86
Author(s):  
Jennifer Mutch ◽  
Martin Sidler ◽  
Claudia Sidler-Maier ◽  
Terry Axelrod ◽  
Diane Nam

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.

2020 ◽  
Vol 23 (2) ◽  
pp. 71-79
Author(s):  
Hyungsuk Kim ◽  
Chang Hyun Yoo ◽  
Soo Bin Park ◽  
Hyun Seok Song

Background: The glenoid version of the shoulder joint correlates with the stability of the glenohumeral joint and the clinical results of total shoulder arthroplasty. We sought to analyze and compare the glenoid version measured by traditional axial two-dimensional (2D) computed tomography (CT) and three-dimensional (3D) reconstructed images at different levels.Methods: A total of 30 cases, including 15 male and 15 female patients, who underwent 3D shoulder CT imaging was randomly selected and matched by sex consecutively at one hospital. The angular difference between the scapular body axis and 2D CT slice axis was measured. The glenoid version was assessed at three levels (midpoint, upper one-third, and center of the lower circle of the glenoid) using Friedman’s method in the axial plane with 2D CT images and at the same level of three different transverse planes using a 3D reconstructed image. Results: The mean difference between the scapular body axis on the 3D reconstructed image and the 2D CT slice axis was 38.4°. At the level of the midpoint of the glenoid, the measurements were 1.7° ± 4.9° on the 2D CT images and −1.8° ± 4.1° in the 3D reconstructed image. At the level of the center of the lower circle, the measurements were 2.7° ± 5.2° on the 2D CT images and −0.5° ± 4.8° in the 3D reconstructed image. A statistically significant difference was found between the 2D CT and 3D reconstructed images at all three levels. Conclusions: The glenoid version is measured differently between axial 2D CT and 3D reconstructed images at three levels. Use of 3D reconstructed imaging can provide a more accurate glenoid version profile relative to 2D CT. The glenoid version is measured differently at different levels.


SICOT-J ◽  
2021 ◽  
Vol 7 ◽  
pp. 32
Author(s):  
Simon A. Hurst ◽  
Lorenzo Merlini ◽  
Ulrich Hansen ◽  
Jules Gregory ◽  
Roger Emery ◽  
...  

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.


2016 ◽  
Vol 25 (6) ◽  
pp. e168-e169
Author(s):  
Eric T. Ricchetti ◽  
Richard A. Cain ◽  
Bong-Jae Jun ◽  
Ari R. Youderian ◽  
Eric J. Rodriguez ◽  
...  

2019 ◽  
pp. 175857321988882
Author(s):  
Sarav S Shah ◽  
Shawn Sahota ◽  
Patrick J Denard ◽  
Matthew T Provencher ◽  
Bradford O Parsons ◽  
...  

Background Two techniques exist from which all 3D preoperative planning software for total shoulder arthroplasty are based. One technique is based on measurements constructed on the mid-glenoid and scapular landmarks (Landmark). The second is an automated system using a best-fit sphere technique (Automated). The purpose was to compare glenoid measurements from the two techniques against a control computed tomography-derived 3D printed scapula. Methods Computed tomography scans of osteoarthritic shoulders of 20 patients undergoing primary total shoulder arthroplasty were analyzed with both 3D planning software techniques. Measurements from a 3D printed scapula (Scapula) from the true 3D computed tomography scan served as controls. Glenoid version and inclination measurements from each group were blinded and reviewed. Results In 65% (Automated) and 45% (Landmark) of cases, either inclination or version varied by 5° or more versus 3D printed scapula. Significant variability in version differences compared to the scapula group existed (p = 0.007). Glenoid version from the Scapula = 13.0° ± 10.6°, Automated = 15.0° ± 13.9°, and Landmark = 12.2° ± 7.8°. Inclination from Scapula = 5.4° ± 7.9°, Automated = 6.1° ± 12.6°, and Landmark = 6.2° ± 9.1°. Discussion A high percentage of cases showed discrepancies in glenoid inclination and version values from both techniques. Surgeons should be aware that regardless of software technique, there is variability compared to measurements from a control 3D computed tomography printed scapula.


2020 ◽  
pp. 175857322090886
Author(s):  
Jourdan M Cancienne ◽  
Ian J Dempsey ◽  
Grant E Garrigues ◽  
Brian J Cole ◽  
Stephen F Brockmeier ◽  
...  

Background The goals of this study were to determine the incidence in the United States of preoperative three-dimensional imaging prior to anatomic total shoulder arthroplasty for osteoarthritis and to determine if preoperative imaging is associated with decreased complication rates. Methods Using a Medicare insurance database, we identified all patients who underwent computed tomography (n = 9380) and/or magnetic resonance imaging (n = 15,653) prior to anatomic total shoulder arthroplasty for a diagnosis of osteoarthritis from 2005 to 2014. The incidence of imaging over time was analyzed and complication rates compared between patients with imaging to matched controls. Results The incidence of preoperative three-dimensional imaging significantly increased over time, with computed tomography increasing more than magnetic resonance imaging. Compared to controls, patients with preoperative computed tomography imaging had significantly lower revision rates at two years (odds ratio 0.72 (0.64–0.82), p = 0.008). There were no other significant differences in the other complications studied. Conclusions The use of preoperative three-dimensional imaging for anatomic total shoulder arthroplasty for a diagnosis of osteoarthritis has increased dramatically, with the use of computed tomography increasing the most. Patients who underwent preoperative computed tomography imaging experienced lower revision rates at two years postoperatively compared to matched controls without such imaging. Level of evidence Level III, retrospective comparative study.


2018 ◽  
Vol 100-B (6) ◽  
pp. 761-766 ◽  
Author(s):  
M. Holschen ◽  
M-K. Siemes ◽  
K-A. Witt ◽  
J. Steinbeck

Aims The reasons for failure of a hemirthroplasty (HA) when used to treat a proximal humeral fracture include displaced or necrotic tuberosities, insufficient metaphyseal bone-stock, and rotator cuff tears. Reverse total shoulder arthroplasty (rTSA) is often the only remaining form of treatment in these patients. The aim of this study was to evaluate the clinical outcome after conversions from a failed HA to rTSA. Material and Methods A total of 35 patients, in whom a HA, as treatment for a fracture of the proximal humerus, had failed, underwent conversion to a rTSA. A total of 28 were available for follow-up at a mean of 61 months (37 to 91), having been initially reviewed at a mean of 20 months (12 to 36) postoperatively. Having a convertible design, the humeral stem could be preserved in nine patients. The stem was removed in the other 19 patients and a conventional rTSA was implanted. At final follow-up, patients were assessed using the American Shoulder and Elbow Surgeons (ASES) score, the Constant Score, and plain radiographs. Results At final follow-up, the mean ASES was 59 (25 to 97) and the mean adjusted Constant Score was 63% (23% to 109%). Both improved significantly (p < 0.001). The mean forward flexion was 104° (50° to 155°) and mean abduction was 98° (60° to 140°). Nine patients (32%) had a complication; two had an infection and instability, respectively; three had a scapular fracture; and one patient each had delayed wound healing and symptomatic loosening. If implants could be converted to a rTSA without removal of the stem, the operating time was shorter (82 minutes versus 102 minutes; p = 0.018). Conclusion After failure of a HA in the treatment of a proximal humeral fracture, conversion to a rTSA may achieve pain relief and improved shoulder function. The complication rate is considerable. Cite this article: Bone Joint J 2018;100-B:761–6.


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