Variability and reliability of 2-dimensional vs. 3-dimensional glenoid version measurements with 3-dimensional preoperative planning software

Inconsistencies in measuring glenoid version in shoulder arthroplasty: a systematic review

BACKGROUND

Glenoid version is a critical anatomic parameter relied upon by many surgeons to inform preoperative planning for shoulder arthroplasty. Advancements in imaging technology have prompted measurements of glenoid version on various imaging modalities with different techniques. However, discrepancies in how glenoid version is measured within the literature have not been well characterized.

METHODS

A literature search was performed by querying PubMed, EMBASE, CINAHL, and Cochrane computerized databases from their inception through December 2023 to identify studies that assessed the relationship between preoperative glenoid version and at least one clinical or radiologic outcome following shoulder arthroplasty. Study quality was assessed via the Methodologic Index for Nonrandomized Studies criteria. Imaging modalities and techniques for measuring glenoid version, along with their association with clinical outcomes, were aggregated.

RESULTS

Among 61 studies encompassing 17,070 shoulder arthroplasties, 27 studies (44.3%) described explicitly how glenoid version was measured. The most common imaging modality to assess preoperative glenoid version was computed tomography (CT) (63.9%), followed by radiography (23%); 11.5% of studies used a combination of imaging modalities within their study cohort. Among the studies using CT, 56.5% utilized two-dimensional (2D) CT, 41.3% utilized three-dimensional (3D) CT, and 2.2% used a combination of 2D and 3D CT. The use of 3D CT increased from 12.5% of studies in 2012-2014 to 25% of studies in 2018-2020 to 52% of studies in 2021-2023 (ptrend = 0.02). Forty-three (70.5%) studies measured postoperative version, most commonly on axillary radiograph (22 [51.2%]); 34.9% of these studies used different imaging modalities to assess pre- and postoperative version.

CONCLUSIONS

This systematic review revealed marked discrepancies in how glenoid version was measured and reported in studies pertaining to shoulder arthroplasty. A temporal trend of increased utilization of 3D CT scans and commercial preoperative planning software was identified. Improved standardization of the imaging modality and technique for measuring glenoid version will enable more rigorous evaluation of its impact on clinical outcomes.

Use of computed tomography for shoulder arthroplasty: A systematic review

Introduction

The prevalence of total shoulder arthroplasties is on the rise annually. Improvements in implant quality, construct stability, and surgical techniques have notably enhanced post-operative results, prompting an expansion of indications for shoulder arthroplasty. Despite its high success rate, opportunities for enhancement remain, especially in preoperative planning and intraoperative execution. Advanced imaging technologies offer significant potential in optimizing implant placement, thus improving the longevity of the procedure. To our knowledge, a comprehensive review examining the impact of advanced imaging on shoulder arthroplasty has yet to be conducted. This systematic review aims to investigate the benefits of advanced imaging technologies in this context, focusing on their application in preoperative planning, osteoarthritis assessment, intraoperative adjustments, patient-specific instrumentation, and navigational aids.

Methods

This review utilized a comprehensive search of PubMed to identify relevant studies published from 2000 to 2024, focusing on the application of various imaging techniques in shoulder arthroplasty. The search was conducted by two authors and centered on plain radiography, CT scans, and MRI. The selection criteria included availability of full-text articles, English language, direct comparison of imaging techniques, and a focus on patient outcomes, including discussions on broader applications such as intraoperative navigation and patient-specific instrumentation development.

Results

Enhanced imaging techniques, particularly CT scans and MRIs, have been shown to significantly improve outcomes in shoulder arthroplasty. While plain radiographs remain standard, CT scans provide superior bony detail, crucial for evaluating glenoid wear and determining augmentation needs. Preoperative CT imaging has been demonstrated to enhance implant placement accuracy. Moreover, intraoperative technologies based on CT imaging, such as patient-specific instrumentation and navigation systems, contribute to better surgical results.

Conclusion

The benefits of CT imaging in shoulder arthroplasty significantly outweigh the associated costs. Current literature strongly supports the adoption of CT imaging in these procedures, particularly when used alongside modern operative technologies.

Comparison of Manual Two-dimensional and Automated Three-dimensional Methods of Assessing Shoulder Joint Morphology through Computed Tomography Images

Objective  To evaluate the interobserver agreement in the measurement of anatomical parameters of the shoulder using manual methods of two-dimensional (2D) computed tomography (CT) unformatted in the plane of the scapula and to compare them with the automated measurement obtained through the Blueprint (Wright Medical, Memphis, TN, United States) software, which uses reconstructed three-dimensional (3D) images. Methods  The present is a cross-sectional study in which 2D CT images of 38 patients with different diagnoses were used. The anatomical parameters were measured by the manual methods described by Friedman et al., the glenoid vault method, the Maurer et al. method, and shoulder subluxation according to Walch et al., by five independent qualified surgeons and compared with the parameters obtained through the Blueprint automated software. Results  Significant differences were found between the manual measurement version obtained through the Friedman et al. method and the automated version. The mean values found for inclination did not show statistically significant differences among the methods. The mean value found for subluxation showed significant differences between the average observed in the analyses performed by the automated method and those performed by the surgeons. Conclusion  The manual measurements of glenoid version and inclination performed by experienced surgeons are effective, and the vault method is superior to the Friedman et al. method in the analysis of severe glenoid deformities.

Rate of incidental findings on routine preoperative computed tomography for shoulder arthroplasty

BACKGROUND

Incidental findings are commonly noted in advanced imaging studies. Few data exist regarding the rate of incidental findings on computed tomography (CT) for preoperative shoulder arthroplasty planning. This study aims to identify the incidence of these findings and the rate at which they warrant further work-up to help guide orthopedic surgeons in counseling patients.

METHODS

A retrospective review was performed to identify patients with available preoperative shoulder CT who subsequently underwent shoulder arthroplasty procedures at a single institution between 2015 and 2021. Data including age, sex, and smoking status were obtained. Radiology reports for CTs were reviewed for incidental findings and categorized based on location, tissue type, and/or body system. The rate of incidental findings and the rate at which further follow-up was recommended by the radiologist were determined.

RESULTS

A total of 617 patients was identified. There were 173 incidental findings noted in 146 of these patients (23.7%). Findings ranged from pulmonary (59%), skin/soft tissue (16%), thyroid (13%), vascular (9%), spinal (2%), and abdominal (1%) areas. Of the pulmonary findings, 50% were pulmonary nodules and 47% were granulomatous disease. Overall, the final radiology report recommended further follow-up for 50% of the patients with incidental findings.

CONCLUSIONS

Incidental findings are relatively common in preoperative CTs obtained for shoulder arthroplasty, occurring in nearly one-quarter of patients. Most of these findings are pulmonary in nature. Overall, half of the patients with incidental findings were recommended for further follow-up. These results establish population data to guide orthopedic surgeons in patient counseling. Level of evidence: III.

3D reconstruction of the scapula from biplanar X-rays for pose estimation and morphological analysis

BACKGROUND

Patient-specific scapular shape in functional posture can be highly relevant to clinical research. Biplanar radiography is a relevant modality for that purpose with already two existing assessment methods. However, they are either time-consuming or lack accuracy. The aim of this study was to propose a new, more user-friendly and accurate method to determine scapular shape.

METHODS

The proposed method relied on simplified manual inputs and an upgraded version of the first 3D estimate based on statistical inferences and Moving-Least Square (MLS) deformation of a template. Then, manual adjustments, with real-time MLS algorithm and contour matching adjustments with an adapted minimal path method, were added to improve the match between the projected 3D model and the radiographic contours. The accuracy and reproducibility of the method were assessed (with 6 and 12 subjects, respectively).

FINDINGS

The shape accuracy was in average under 2 mm (1.3 mm in the glenoid region). The reproducibility study on the clinical parameters found intra-observer 95% confidence intervals under 3 mm or 3° for all parameters, except for glenoid inclination and Critical Shoulder Angle, ranging between 3° and 6°.

INTERPRETATION

This method is a first step towards an accurate reconstruction of the scapula to assess clinical parameters in a functional posture. This can already be used in clinical research on non-pathologic bones to investigate the scapulothoracic joint in functional position.

Difference analysis of the glenoid centerline between 3D preoperative planning and 3D printed prosthesis manipulation in total shoulder arthroplasty

INTRODUCTION

Excessive version and inclination of the glenoid component during total shoulder arthroplasty can lead to glenohumeral instability, early loosening, and even failure. The orientation and position of the central pin determine the version and inclination of the glenoid component. The purpose of this study was to compare the differences in centerline position and orientation obtained using "3D preoperative planning based on the best-fit method for glenoid elements" and the surgeon's manipulation.

MATERIALS AND METHODS

Twenty-nine CT images of glenohumeral osteoarthritis of the shoulder were reconstructed into a 3D model, and a 3D printer was used to create an in vitro model for the surgeon to drill the center pin. The 3D shoulder model was also used for 3D preoperative planning (3DPP) using the best-fit method for glenoid elements. The in vitro model was scanned and the version, inclination and center position were measured to compare with the 3DPP results.

RESULTS

The respective mean inclinations (versions) of the surgeon and 3DPP were -2.63° ± 6.60 (2.87° ± 5.97) and -1.96° ± 4.24 (-3.21° ± 4.00), respectively. There was no significant difference in the inclination and version of the surgeon and 3DPP. For surgeons, the probability of the inclination and version being greater than 10° was 13.8% (4/29) and 10.3% (3/29), respectively. Compared to the 3DPP results, the surgeon's center position was shifted down an average of 1.63 mm. There was a significant difference in the center position of the surgeon and 3DPP (p < 0.05).

CONCLUSION

The central pin drilled by surgeons using general instruments was significantly lower than those defined using 3D preoperative planning and standard central definitions. 3D preoperative planning prevents the version and inclination of the centerline from exceeding safe values (± 10°).

Pre-operative arthritic glenoid assessment: 3D automated planning software versus manual multiplanar measurements of version and inclination

Background

Preoperative CT-based planning is established in shoulder arthroplasty surgery. Automated planning software has become available to assist the surgeon and may increase reliability and efficiency. This study aims to evaluate the reliability of an automated 3-dimensional (3D) planning software package (Blueprint™ v2.1.5, Wright Medical Ltd) in the assessment of the arthritic shoulder against manual multiplanar measurement (MM).

Methods

74 CT studies acquired for preoperative shoulder arthroplasty planning were reviewed on two occasions by four different evaluators, taking manual measurement (MM) of glenoid version and inclination adjusted with multiplanar reformation and adhering to modified Freidman and Maurier methods. 15 scans were not processed by Blueprint due to incompatible scanning protocols or severe scapular dysmorphia. 59 Blueprint measures were compared with the manual data.

Results

Version: Intra-observer reliability of glenoid version MM was excellent (mean ICC 0.92). Inter-observer reliability between all four readers was good (ICC 0.89). A Bland-Altman analysis of Blueprint versus MM for version measurements demonstrated a mean pair difference of -5.77 (95% CI -7.25 to 4.29). Inclination: Intra-rater and inter-rater reliabilities were good (ICC 0.85 and 0.80 respectively). Blueprint and MM values for inclination followed a more convergent pattern than for version. Bland-Altman analysis for inclination did not show substantial bias, with a mean pair difference of 1.4 (95% CI -0.1 to 2.9).

Conclusion

Manual preoperative planning for shoulder arthroplasty is time consuming and requires experience. Automated 3D planning offers a consistent tool to assist the surgeon, notwithstanding intra-operative anatomical and technical variation, and margin of error. Surgeons should as ever be mindful of the specifics of a given automated program and our data quantified a bias for retroversion which may be important for measures close to the thresholds for augmentation or customised implants.