Quantifying bone loss and lateralization with standardized baseplate versus augmented baseplates.

Background: Reverse shoulder arthroplasty continues to be utilized for the treatment of cuff tear arthropathy, glenohumeral degenerative joint disease, and irreparable rotator cuff tears. With advancement in component designs, glenoid retroversion and inclination are now correctable with augmented baseplates. However, quantifying bone loss and lateralization compared to standard baseplates has not been studied. The purpose of the current study is to determine the volume of bone reamed and net lateralization with a standardized baseplate vs. augmented baseplate when glenoid inclination was corrected to neutral. Methods: A series of 21 computed tomography scans of patients presenting for shoulder arthroplasty were chosen based on a range of increasing native positive inclination. Computed tomography scans were uploaded into segmentation software and processed. Four fellowship trained shoulder surgeons were then blinded from each other and virtually placed a neutral baseplate and an augmented baseplate for each specimen. Baseplate position was standardized. Additionally, baseplate backside seating of a minimum of 80% was also standardized and glenosphere (nonlateralized) size was selected to eliminate variation in baseplate contact and position. Glenoid inclination was corrected to a minimal of neutral in each specimen as well as glenoid retroversion corrected to <10°. Net lateralization from the center of the glenoid to the most lateral aspect of the baseplate was calculated in millimeters. Results: The mean glenoid retroversion was 8.1° and superior inclination was 10.6° for all specimens. Across all specimens and surgeons, use of a 10-degree augment resulted in similar baseplate backside seating area (219.2 mm3 vs. 226.2 mm3, P > .05). There was substantially lower volume of bone reamed in the augmented baseplate patients (619 mm3 vs. 1102 mm3, P < .001). Larger standard deviation seen in the augmented baseplate columns are attributed to differences in surgeon preference for percent backside seating, which was standardized at a minimum of 80%. Use of a 10-degree full wedge augment resulted in 2.4 mm additional glenoid lateralization than a neutral baseplate on average across all included scapulae. Conclusion: The current study demonstrates approximately 50% less bone removal and 2.4 mm of true lateralization with a 10-degree augmented baseplate when compared to standard baseplates.

The impact of 3-dimensional humeral planning and standard transfer instrumentation on reconstruction of native humeral anatomy for anatomic total shoulder arthroplasty.

BACKGROUND: Preoperative 3-dimensional (3D) computed tomography (CT)-based planning for anatomic total shoulder arthroplasty (TSA) has grown in popularity in the past decade with the primary focus on the glenoid. Little research has evaluated if humeral planning has any effect on the surgical execution of the humeral cut or the positioning of the prosthesis. METHODS: Three surgeons performed a prospective study using 3D-printed humeri printed from CTs of existing patients, which were chosen to be -3, -1, 0, 1, and 3 standard deviations of all patients in a large database. A novel 3D printing process was used to 3D print not only the humerus but also all 4 rotator cuff tendons. For each surgical procedure, the printed humerus was mounted inside a silicone shoulder, with printed musculature and skin, and with tensions similar to human tissue requiring standard retraction and instruments to expose the humerus. Three phases of the study were designed. In phase 1, humeral neck cuts were performed on all specimens without any preoperative humeral planning; in phase 2, 3D planning was performed, and the cuts and implant selection were repeated; in phase 3, a neck-shaft angle (NSA) guide and digital calipers were used to measure humeral osteotomy thickness to aid in the desired humeral cut. All humeri were digitized. The difference between the prosthetic center of rotation (COR) and ideal COR was calculated. The percentage of patients with a varus NSA was calculated for each phase. The difference in planned and actual cut thickness was also compared. RESULTS: For both 3D change in COR and medial to lateral change in COR, use of preoperative planning alone and with standard transfer instrumentation resulted in a significantly more anatomic restoration of ideal COR. The deviations from planned cut thickness decreased with each phase: phase 1: 2.6 ± 1.9 mm, phase 2: 2.0 ± 1.3 mm, phase 3: 1.4 ± 0.9 mm (P = .041 for phase 3 vs. phase 1). For NSA, in phase 1, 7 of 15 (47%) cases were in varus; in phase 2, 5 of 15 (33%) were in varus; and in phase 3, 1 of 15 (7%) cases was in varus (P = .013 for phase 3 vs. phase 1). CONCLUSIONS: Use of preoperative 3D humeral planning for stemless anatomic TSA improved prosthetic humeral COR, whether performed with or without standard transfer instrumentation. The use of an NSA cut guide and calipers to measure cut thickness significantly reduced the percentage of varus humeral cuts and deviation from planned cut thickness.

Influence of backside seating parameters and augmented baseplate components in virtual planning for reverse shoulder arthroplasty.

BACKGROUND: The primary goal of this investigation was to examine the influence of a backside seating percentage variable on volume of reamed bone and contact area in virtual planning for glenoid baseplate placement for reverse total shoulder arthroplasty (RTSA). The secondary goal was to assess how the option of augmented glenoid baseplate components affected reamed volume and cortical contact area of virtually positioned baseplates. METHODS: Nine surgeons virtually planned 30 RTSA cases using a commercially available software system. The 30 cases were chosen to span a spectrum of glenoid deformity. The study consisted of 3 phases. In phase 1, cases were planned with the backside seating percentage blinded and without the option of augmented baseplate components. In phase 2, the backside seating parameter was unblinded. In phase 3, augmented baseplate components were added as an option. Implant version and inclination were recorded. By use of computer-assisted design models, total volume of bone reamed, as well as reamed cortical volume and cancellous volume, was calculated. Total, cortical, and cancellous baseplate contact areas were also calculated. Finally, total glenoid lateralization was calculated for each phase and compared. RESULTS: Mean implant version was clinically similar across phases but was statistically significantly lower in phase 3 (P = .006 compared with phase 1 and P = .001 compared with phase 2). Mean implant inclination was clinically similar across phases but was statistically significantly lower in phase 3 (P < .001). Phase 3 had statistically significantly lower cancellous and total reamed bone volumes compared with phase 1 and phase 2 (P < .001 for all comparisons). Phase 3 had statistically significantly larger cortical contact area, lower cancellous contact area, and larger total contact area compared with phase 1 and phase 2 (P < .001 for all comparisons). Phase 3 had significantly greater glenoid lateralization (mean, 10.5 mm) compared with phase 1 (mean, 7.8 mm; P < .001) and phase 2 (mean, 7.9 mm; P < .001). CONCLUSIONS: Across a wide range of glenoid pathology during virtual surgical planning, experienced shoulder arthroplasty surgeons chose augmented baseplates frequently, and the option of a full-wedge augmented baseplate resulted in statistically significantly greater correction of glenoid deformity, improved total and cortical baseplate contact area, less cancellous reamed bone, and greater glenoid lateralization. Backside seating information does not have a significant impact on how glenoid baseplates are virtually positioned for RTSA, nor does it impact the baseplate contact area or volume of reamed bone.

Nail it! vision-based drift correction for accurate mixed reality surgical guidance.

PURPOSE: Mixed reality-guided surgery through head-mounted displays (HMDs) is gaining interest among surgeons. However, precise tracking of HMDs relative to the surgical environment is crucial for successful outcomes. Without fiducial markers, spatial tracking of the HMD suffers from millimeter- to centimeter-scale drift, resulting in misaligned visualization of registered overlays. Methods and workflows capable of automatically correcting for drift after patient registration are essential to assuring accurate execution of surgical plans. METHODS: We present a mixed reality surgical navigation workflow that continuously corrects for drift after patient registration using only image-based methods. We demonstrate its feasibility and capabilities using the Microsoft HoloLens on glenoid pin placement in total shoulder arthroplasty. A phantom study was conducted involving five users with each user placing pins on six glenoids of different deformity, followed by a cadaver study by an attending surgeon. RESULTS: In both studies, all users were satisfied with the registration overlay before drilling the pin. Postoperative CT scans showed 1.5 mm error in entry point deviation and 2.4[Formula: see text] error in pin orientation on average in the phantom study and 2.5 mm and 1.5[Formula: see text] in the cadaver study. A trained user takes around 90 s to complete the workflow. Our method also outperformed HoloLens native tracking in drift correction. CONCLUSION: Our findings suggest that image-based drift correction can provide mixed reality environments precisely aligned with patient anatomy, enabling pin placement with consistently high accuracy. These techniques constitute a next step toward purely image-based mixed reality surgical guidance, without requiring patient markers or external tracking hardware.

Comparing the accuracy of ultrasound versus fluoroscopy in glenohumeral injections: a systematic review and meta-analysis.

OBJECTIVE: We performed a systematic review with meta-analysis to compare the accuracy of fluoroscopic-guided glenohumeral injections with that of ultrasound-guided glenohumeral injections as reported in prior studies. METHODS: We reviewed the databases of MEDLINE, PubMed, and Google Scholar using combinations of the keywords "ultrasound," "fluoroscopy," "injection," and "shoulder" for articles reporting the injection accuracy, confirmed by imaging, of the first attempt under either fluoroscopic or ultrasound guidance. A meta-analysis was performed to assess the accuracy of fluoroscopic-guided glenohumeral injections versus ultrasound-guided glenohumeral injections. RESULTS: Five of 42 pertinent studies met our inclusion criteria for a total of 406 glenohumeral injections, of which 115 were fluoroscopy-guided and 291 were ultrasound-guided. The meta-effect estimates for the proportion of joints successfully injected with ultrasound and fluoroscopic guidance were 93% (95% CI, 86% to 98%) and 80% (95% CI, 63% to 93%), respectively, which did not reach statistical significance (Q[df] = 2.55 [1], p = 0.11). CONCLUSIONS: Our meta-analysis indicates that glenohumeral injections guided by ultrasound are more accurate than injections guided by fluoroscopy but this difference did not reach statistical significance. As the use of ultrasound does not expose the patient or practitioner to radiation, its similar accuracy may make it the preferred modality for image-guided glenohumeral joint injections. Limitations to our analysis include the retrospective nature, limited number of studies included, and the potential generalizability of our findings to regions outside of those included in our study.

The use of vascular closure devices and impact on major bleeding and net adverse clinical events (NACEs) in balloon aortic valvuloplasty: a sub-analysis of the BRAVO study.

OBJECTIVE: To determine the impact of suture-mediated vascular closure devices (VCDs) on net adverse clinical events (NACEs) after balloon aortic valvuloplasty (BAV). BACKGROUND: Ischemic and bleeding complications are common following transfemoral BAV; however, previous studies have been single center and limited by varying definitions of major bleeding. METHODS: The Effect of Bivalirudin on Aortic Valve Intervention Outcomes (BRAVOs) study was a retrospective observational study conducted at two high-volume academic centers over a 6-year period designed to compare the effect of bivalirudin versus unfractionated heparin. This is a subanalysis of 428 consecutive patients who underwent BAV (with 10-13 French sheaths) to compare the effect of hemostasis with VCDs versus manual compression utilizing standardized definitions. NACE was defined as the composite of major bleeding and major adverse clinical events (MACEs). All events were adjudicated by an independent clinical events committee who were blinded to antithrombin use. RESULTS: Preclosure was performed in 269 (62.8%) of patients. While bivalirudin was used more frequently in those with pre-closure (60.6% vs. 37.7%, P < 0.001), a history of prior BAV (11.1% vs. 3.6%, P = 0.04) and peripheral vascular disease (30.7% vs. 19.7%, P = 0.01) was more common in those not undergoing preclosure (n = 159, 37%). Other clinical and demographic features were well balanced between groups. Vascular closure was associated with a significant reduction in NACE (24.5% vs. 10.0% P < 0.001). Results remained significant after adjusting for baseline differences and bivalirudin use (OR 0.38, 95% CI: 0.21-0.68; P = 0.001). CONCLUSIONS: Our study suggests that suture-mediated vascular closure is associated with a substantial reduction in NACE after transfemoral BAV. Large randomized clinical trials should be conducted to confirm our results.

What gets measured gets done: assessing data availability for adolescent populations.

OBJECTIVES: To identify specific adolescent sub-populations; to evaluate the health data available regarding these populations related to 21 key national adolescent health objectives from Healthy People 2010; and to make recommendations for improving data capacity to further efforts to reduce health disparities among adolescents. METHODS: Adolescent populations were identified through a consensus process. Academic and government literature was extensively reviewed using internet search techniques to identify available national data for each of these populations on each key national health objective. RESULTS: 18 adolescent subpopulations were identified. These populations fit into four overlapping categories defined by demography, legal status, chronic health condition, or other special characteristics. Overall, national, population-based data regarding these sub-populations were located for 36% of the 21 health objectives. Within the sub-populations, most data was available for ethnic/racial groups, with 57-81% of each of the objectives having data. Data regarding rural/urban groups were found for about one-half of the 21 objectives, and data were located on all other groups for one-fourth or fewer of the objectives. Within the objectives, substance abuse objectives were the most widely measured, with data available for 56-78% of the various populations. For some objectives, such as drug-or alcohol-related motor vehicle deaths depression among the developmentally disabled, no national data were found. CONCLUSIONS: There are still too little data available regarding the specific health status or health objectives for different adolescent populations. A national adolescent data-priority agenda is needed to develop strategies to improve health data regarding adolescent sub-populations. Federal and state health monitoring agencies could create national health profiles of different populations, include more population markers in health studies, and develop tools for population-specific health assessment, particularly for those within the government's care, including incarcerated and foster care youth.