Revision shoulder arthroplasty is increasing with the number of primary shoulder replacements rising globally. Complex primary and revisions of shoulder arthroplasties pose specific challenges for the surgeon, which must be addressed preoperatively and intraoperatively. This article aimed to present strategies for the management of revision of shoulder arthroplasties through a single-stage approach. Preoperatively, patient factors, such as age, comorbidities, and bone quality, should be considered. The use of planning software can aid in accurately evaluating implants in situ and predict bony anatomy that will remain after explantation during the revision surgery. The planning from such software can then be executed with the help of mixed reality technology to allow accurate implant placement. Single-stage revision is performed in two steps (debridement as first step, implantation and reconstruction as the second step), guided by the following principles: adequate debridement while preserving key soft tissue attachments (i.e., rotator cuff, pectoralis major, latissimus dorsi, deltoid), restoration of glenoid joint line using bone grafting, restoration of humeral length, reconstruction and/or reattachment of soft tissues, and strict compliance with the postoperative antibiotic regimen. Preliminary results of single-stage revision shoulder arthroplasty show improvement in patient outcomes (mean 1 year), successful treatment of infection for those diagnosed with periprosthetic joint infection, and improved cost–benefit parameters for the healthcare system.

Background: The use of reverse shoulder arthroplasty as a primary and revision implant is increasing. Advances in implant design and preoperative surgical planning allow the management of complex glenoid defects. As the demand for treating severe bone loss increases, custom allograft composites are needed to match the premorbid anatomy. Baseplate composite structural allografts are used in patients with eccentric and centric defects to restore the glenoid joint line. Preserving bone stock is important in younger patients where a revision surgery is expected. The aim of this article is to present the assessment, planning, and indications of femoral head allografting for bony defects of the glenoid. Methods: The preoperative surgical planning and the surgical technique to execute the plan with a baseplate composite graft are detailed. The preliminary clinical and radiological results of 29 shoulders which have undergone this graft planning and surgical technique are discussed. Clinical outcomes included visual analogue score of pain (VAS), American Shoulder and Elbow Surgeons score (ASES), Constant–Murley score (CS), satisfaction before and after operation, and active range of motion. Radiological outcomes included graft healing and presence of osteolysis or loosening. Results: The use of composite grafts in this series has shown excellent clinical outcomes, with an overall graft complication rate in complex bone loss cases of 8%. Conclusion: Femoral head structural allografting is a valid and viable surgical option for glenoid bone defects in reverse shoulder arthroplasty.

Restoration of the glenoid joint line in shoulder arthroplasty is important for implant positioning and function. Medialization of the glenohumeral joint line due to glenoid bone loss is commonly encountered in primary and revision of shoulder arthroplasty albeit the direction and location of bone loss varies with different pathology. Three-Dimensional (3D) planning software has assisted in preoperative planning of complex glenoid deformities. However, limited literature is available defining a reliable 3D method to evaluate the glenoid joint line preoperatively. The purpose of this study is to identify a set of reliable scapular landmarks to be used as reference points to measure the premorbid glenoid joint line using 3D segmented models of healthy scapulae. Bilateral computed tomography scans from 79 patients eligible for primary stabilization procedures were retrospectively selected from our institutional surgical database (mean age 35 ± 10 years, 58 males and 21 females). 3D models of the contralateral healthy scapulae were created via computed tomography scan segmentation using Mimics 24.0 software (Materialise, Leuven, Belgium). Anatomical landmarks were identified using 3-Matic 16.0 software (Materialise, Leuven, Belgium). The distance between identified landmarks and a sagittal plane created on the deepest point of the glenoid was recorded for each scapula and reliability of each landmark was assessed. Inter- and intra-observer reliabilities were also evaluated using intraclass correlation coefficients (ICCs). Four landmarks showed statistically significant results: the scapular notch (SN), the centroid of the coracoid (CC), a point on the most medial border of the scapula in line with the scapular spine (TS), and the most lateral point of the acromion (AL). The mean (± standard deviation) joint line measured from the SN, CC, TS and AL were 28.36 ± 2.97 mm, 11.66 ± 2.07 mm, 107.52 ± 8.1 mm, and 29.72 ± 4.46 mm, respectively. Inter-observer reliability analysis for SN, TS, and AL showed excellent agreement with ICC values of 0.966, 0.997, and 0.944, respectively, and moderate agreement for CC with ICC of 0.728. The results from this study assist in estimating joint line medialization preoperatively and in planning its subsequent restoration. A set of reliable landmarks can be used as references to estimate the premorbid glenoid joint line preoperatively.

Background: Component positioning affects clinical outcomes of reverse shoulder arthroplasty, which necessitates an implantation technique that is reproducible, consistent, and reliable. This study aims to assess the accuracy and precision of positioning the humeral component in planned retroversion using a forearm referencing guide. Methods: Computed tomography scans of 54 patients (27 males and 27 females) who underwent primary reverse shoulder arthroplasty for osteoarthritis or cuff tear arthropathy were evaluated. A standardized surgical technique was used to place the humeral stem in 15 degrees of retroversion. Version was assessed intraoperatively visualizing the retroversion guide from above and referencing the forearm axis. Metal subtraction techniques from postoperative computed tomography images allowed for the generation of 3D models of the humerus and for evaluation of the humeral component position. Anatomical humeral plane and implant planes were defined and the retroversion 3D angle between identified planes was recorded for each patient. Accuracy and precision were assessed. A subgroup analysis evaluated differences between male and female patients. Results: The humeral retroversion angle ranged from 0.9 degrees to 22.8 degrees. The majority (81%) of the measurements were less than 15 degrees. Mean retroversion angle (+/- SD) was 9.9 degrees +/- 5.8 degrees (95% CI 8.4 degrees-11.5 degrees) with a mean percent error with respect to 15 degrees of -34% +/- 38 (95% CI -23 to -44). In the male subgroup (n = 27, range 3.8 degrees-22.5 degrees), the mean retroversion angle was 11.9 degrees +/- 5.4 degrees (95% CI 9.8 degrees-14.1 degrees) with a mean percent error with respect to 15 degrees of - 21% +/- 36 (95% CI -6 to - 35). In the female subgroup (n = 27, range 0.9 degrees -22.8 degrees ), mean retroversion angle was 8.0 degrees +/- 5.5 degrees (95% CI 5.8 degrees -10.1 degrees ) and the mean percent error with respect to 15 degrees was - 47% +/- 36 (95% CI -32 to - 61). The differences between the 2 gender groups were statistically significant ( P = .006). Conclusion: Referencing the forearm using an extramedullary forearm referencing system to position the humeral stem in a desired retroversion is neither accurate nor precise. There is a nonnegligible tendency to achieve a lower retroversion than planned, and the error is more marked in females. Level of evidence: Level II; Study of a Diagnostic Test (c) 2023 The Author(s). This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Background: Proximal humeral bone deficiency in revision shoulder arthroplasty is an emerging and challenging problem as the use of reverse shoulder arthroplasty (RSA) increases. This paper presents a technical note discussing our detailed preoperative planning steps, surgical techniques, and their rationale in carrying out the use of an allograft prosthetic composite (APC) to address proximal humeral bone deficiency in revision RSA. The outcomes of this technique are also presented. This paper also presents a systematic review to further discuss the existing literature on RSA with APCs. Methods: The preoperative surgical planning and the surgical technique employed to execute proximal humeral reconstruction using APC during revision arthroplasty are discussed in the technical note. The preliminary clinical and radiological results of five patients who underwent revision shoulder arthroplasty with proximal humeral reconstruction using APCs are presented. The PRISMA guidelines were followed to perform the systematic review. A systematic search using PubMed, Embase, and Cochrane databases was conducted. All studies involving RSA and APCs were pooled, and the data were extracted and analyzed. Results: A total of 14 studies were eligible for inclusion in the systematic review, with a total of 255 patients and a mean follow-up of 57 months. All studies in the systematic review and the patients included in the author’s case series showed improvements in the level of pain, range of motion, function, and satisfaction. Graft incorporation in the systematic review was 84%. Conclusions: Based on the available literature and the results of our case series, the use of an APC construct is a viable option for proximal humeral bone deficiency in revision shoulder arthroplasty.

Mixed reality (MR) is an emerging technology that aids surgeons during shoulder arthroplasty. This study aims to evaluate surgeons’ ability to reproduce preoperatively planned implant positioning using MR technology as compared to the conventional freehand (FH) technique and the more established guidance technique of navigation for shoulder arthroplasty. Three surgeons with different levels of shoulder arthroplasty experience inserted guidewires into five three-dimensional–printed scapula models with varying degrees of glenoid deformity using the FH technique, MR overlay technique, and navigation. Postprocedure computed tomography scans of the sixty three-dimensional–printed glenoid models with inserted guidewire were performed. The executed guidewire entry point, version, and inclination were compared to the preoperative plan. The use of MR for guidewire positioning was significantly better than FH technique for inclination (P < .001), but not for version (P = .221) and entry point (P = .062). Malposition rate decreased from 66.7% with FH technique to 40% when MR was used for guidance, but this did not reach statistical significance (P = .143). MR overlay technique was not shown to be statistically significantly more accurate than navigation. MR overlay technique significantly improves the accuracy of guidewire placement in terms of inclination as compared to the standard FH technique. It is still inferior to navigation for all variables. When the two guidance techniques are combined, MR overlay with navigation could be an effective tool and harness the best of both technologies in the future.