Mako robotic-assisted glenoid preparation in reverse shoulder arthroplasty: a tail-risk reduction perspective compared with manual and patient-specific guide techniques.

What's New in Shoulder and Elbow Surgery.

What's New in Shoulder and Elbow Surgery.

Revision reverse shoulder arthroplasty has similar outcomes to primary reverse shoulder arthroplasty at 5 Year average follow-up

Purpose:Glenoid component malposition is associated with poor function and early failure of both anatomic and reverse total shoulder arthroplasty. Glenoid positioning is challenging particularly in the setting of bone loss or deformity. Recently, the use of computer assistance has been shown to reduce implantation error. The aim of this study is to evaluate the accuracy of patient-specific instrumentation in cases of anatomic and reverse shoulder replacement in vivo.Methods:Twenty patients underwent total shoulder arthroplasty using a computed tomography (CT)-based patient-specific instrumentation (PSI) system, ten anatomic and ten reverse. Preoperative three-dimensional digital templating of glenoid component position was undertaken and surgery then performed using a custom-made guide. Postoperative CT scans were used to compare final implanted component position to the preoperatively planned position in the same patient.Results:Final component position and orientation closely reflected the preoperatively templated position. Mean deviation in the glenoid version from planned was 1.8° ±1.9° (range, 0.1°–7.3°). Mean deviation in inclination was 1.3° ±1.0° (range, 0.2°–4.5°). Mean deviation in position on the glenoid face was 0.5 ± 0.3 mm (range, 0.0–1.3 mm) in the anteroposterior plane and 0.8 ± 0.5 mm (range, 0.0–1.9 mm) in the superoinferior plane. Actual achieved version was within 7° of neutral in all cases except for one where it was deliberately planned to be outside of this range.Conclusion:PSI in both anatomic and reverse shoulder arthroplasty is highly accurate in guiding glenoid component implantation in vivo. The system can reliably correct bony deformity.

Comparison of 3D computer-assisted planning with and without patient-specific instrumentation for severe bone defects in reverse total shoulder arthroplasty

Inadequate subscapularis repair has been advocated as one of the contributing factors for dislocation in reverse total shoulder arthroplasty; nonetheless the need to restore the subscapularis tendon integrity is under debate. The aim of this systematic review was to answer the question: does subscapularis reattachment following reverse total shoulder arthroplasty improve joint stability, range of motion and functional scores? The literature was systematically screened in accordance with PRISMA guidelines looking for papers evaluating clinical outcomes of reverse total shoulder arthroplasty in relation to the management of subscapularis tendon. Studies comparing clinical outcomes, complications and dislocation rate with or without subscapularis repair were included. Studies in which reverse total shoulder arthroplasty was performed for trauma or tumors were excluded. The methodology of included articles was scored with MINORS scale and the Risk of Bias was assessed adopting the ROBINS-I (Risk Of Bias In Non-randomized Studies of Interventions) developed by the Cochrane Group. A meta-analysis was also performed combining the studies to increase the sample size and hence the power to obtain meaningful data. The database search identified 1062 records, and 6 full-text articles were finally included. A total number of 1085 reverse total shoulder arthroplasty were assessed on. Except for one study, lateralized prosthetic designs have been used. Dislocation occurred in 0.8% (5/599 patients) of the patient with repaired subscapularis and in 1.6% (8/486 patients) of the tenotomized patients, and subscapularis repair was not associated with a higher risk of dislocation (pooled Peto OR: 0.496, 95% CI: 0.163 to 1.510, p = 0.217). Qualitative assessment revealed no differences in the range of motion and clinical scores. Subscapularis repair after reverse total shoulder arthroplasty produces no clinically meaningful benefits, particularly using lateralized prosthetic designs. Subscapularis re-attachment does not improve implant stability, nor increases range of motion or clinical scores. Given these results, keeping in mind the antagonistic effect of the repaired subscapularis on external rotation, no evidence lead to suggest subscapularis reattachment following reverse total shoulder arthroplasty with lateralized prosthetic designs.

Precise and accurate glenoid preparation is important for the success of shoulder arthroplasty. Despite advancements in preoperative planning software and enabling technologies, most surgeons execute the procedure manually. Patient-specific instrumentation (PSI) facilitates accurate glenoid guide pin placement for cannulated reaming; however, few commercially available systems offer depth of reaming control. Robotic arm-assisted bone preparation has gained popularity in knee and hip arthroplasty, but at the present time there is limited information available on the use of robotics for shoulder arthroplasty. The purpose of this study was to compare glenoid preparation and final implant position using 3 techniques: manual, manual assisted with PSI, and robotic arm-assisted bone preparation. Six shoulder surgeons participated in this study using 3 preparation techniques: (1) manual reaming, (2) manual reaming over a pin inserted using PSI, and (3) preparation using a robotic arm assist with an end-effector burr and haptic boundaries. Each surgeon randomly conducted each technique on 2 separate Bone Matrix glenoid models, for a total of 36 glenoid models tested. To compare the techniques, the final prepared Bone Matrix models underwent a computed tomographic scan with 3D virtual model generation. The prepared 3D virtual glenoid models were then compared to the preoperatively planned models. Parameters compared included deviations in version, inclination, anterior-posterior (AP) translation, superior-inferior (SI) translation, and depth of reaming. Regarding glenoid version with values reported as mean deviations from the preoperative plan, the robotic-assisted technique (1°) was significantly better than manual (9°, P < .001) and PSI (4°, P < .001) techniques at executing the preoperative plan. Regarding inclination, the robotic-assisted technique (2°) was significantly better than manual (9°, P = .003) but not significantly different than PSI (3°, P = .211). The robotic arm technique, with AP translation, resulted in significantly lower mean displacements (0.3 mm) than the manual technique (2 mm, P = .001) and the PSI technique (2 mm, P = .002). With SI translation, the robotic arm-assisted technique (0.7 mm) resulted in significantly lower mean displacements as compared to the manual (2 mm, P = .007) and PSI (1 mm, P = .011). The robotic arm-assisted technique (0.4 mm) did not result in significantly lower mean depth of reaming displacements compared to the manual technique (0.8 mm, P = .051) but did when compared to PSI (0.8 mm, P = .036). Glenoid preparation using a robotic arm with an end-effector burr and haptic boundaries was significantly better in its ability to execute a preoperatively planned implant position than manual preparation in 4 of the 5 glenoid metrics examined and was significantly better than PSI in 4 of the 5 glenoid metrics.

The anterior deltoid's importance in reverse shoulder arthroplasty: a cadaveric biomechanical study

Comparative analysis of anatomic and reverse total shoulder arthroplasty: in-hospital outcomes and costs

Complications and implant survivorship following primary reverse total shoulder arthroplasty in patients younger than 65 years: a systematic review

A method for documenting the change in center of rotation with reverse total shoulder arthroplasty and its application to a consecutive series of 68 shoulders having reconstruction with one of two different reverse prostheses

Comparison of clinical outcomes of revision reverse total shoulder arthroplasty for failed primary anatomic vs. reverse shoulder arthroplasty

Glenoid baseplate malpositioning during reverse total shoulder arthroplasty can contribute to perimeter impingement, dislocation, and loosening. Despite advances in preoperative planning, conventional instrumentation may lead to considerable inaccuracy in implant positioning unless patient-specific guides are used. Optical navigation has the potential to improve accuracy and precision when implanting a reverse shoulder arthroplasty baseplate. This systematic review aimed to analyze the most recent evidence on the accuracy and precision of glenoid baseplate positioning using intraoperative navigation and its potential impact on component selection and surgical time. We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. The PubMed, Scopus, and EMBASE databases were queried in July 2022 to identify all studies that compared navigation vs. conventional instrumentation for reverse shoulder arthroplasty. Data of deviation from the planned baseplate version and inclination, the use of standard or augmented glenoid components, and surgical time were extracted. Quantitative analysis from the included publications was performed using the inverse-variance approach and Mantel-Haenszel method. Of the 2,048 records identified in the initial query, only 10 articles met the inclusion and exclusion criteria, comprising 667 shoulders that underwent reverse total shoulder arthroplasty. The pooled mean difference (MD) of the deviation from the planned baseplate position for the clinical studies was -0.44 (95% confidence interval [CI], -3.26; p = 0.76; I2 = 36%) for version and -8.75 (95% CI, -16.83 to -0.68; p = 0.02; I2 = 83%) for inclination, both in favor of navigation. The odds ratio of selecting an augmented glenoid component after preoperative planning and navigation-assisted surgery was 8.09 (95% CI, 3.82-17.14; p < 0.00001; I2 = 60%). The average surgical time was 12 minutes longer in the navigation group (MD 12.46, 95% CI, 5.20-19.72; p = 0.0008; I2 = 71%). Preoperative planning integrated with computer-assisted navigation surgery seems to increase the accuracy and precision of glenoid baseplate inclination compared with the preoperatively planned placement during reverse total shoulder arthroplasty. The surgical time and proportion of augmented glenoid components significantly increase when using navigation. However, the clinical impact of these findings on improving prosthesis longevity, complications, and patient functional outcomes is still unknown. Level III, systematic review and meta-analysis. See Instructions for Authors for a complete description of levels of evidence.

Where Are We Now? The frequency of shoulder arthroplasty in today's population has increased, in part due to the growing number of older patients with degenerative and traumatic disorders of the shoulder, as well as the extension of arthroplasty solutions to younger patients who feel they have exhausted reasonable nonsurgical alternatives. As a consequence, more revision shoulder arthroplasties should be anticipated. From its introduction for narrow indications into the United States more than a decade ago, reverse shoulder arthroplasty has emerged as the preferred treatment, in many instances, for failed shoulder arthroplasties that require prosthetic revision. However, the severity and frequency of complications with this approach are well described. It also is clear that patients undergoing reverse shoulder arthroplasty as part of a revision shoulder arthroplasty do not do as well as those undergoing reverse total shoulder arthroplasty for cuff-tear arthropathy, failed rotator cuff repairs, and posttraumatic sequelae. Part of this difference may derive from the need, in many instances, to remove the existing humeral prosthesis. The paper by Wagner et al. supports this idea; 16% (36 of 230) patients undergoing revision to a reverse total shoulder arthroplasty experienced an intraoperative humerus fracture, and most of these fractures occurred during removal of the humeral component. While the authors mention that the frequency of intraoperative fractures was higher during revision arthroplasty with a reverse versus anatomic component, the reader is left to speculate the reasons for the difference. Curiously, only in the presence of hemiarthroplasty, as opposed to total shoulder arthroplasty, was the risk of intraoperative fracture increased. Perhaps the majority of hemiarthroplasties were performed for fracture treatment, and resulted in variable patterns and degrees of tuberosity union, all of which may add complexity and risk to component explantation. Where Do We Need To Go? With nearly four decades of experience with shoulder arthroplasty at their institution, the authors are much better prepared than most surgeons to mitigate the occurrences and effects of intraoperative complications of shoulder arthroplasty, such as periprosthetic fractures of the humerus during revision reverse shoulder arthroplasty as reported in this paper. It would benefit the reader to know what technical measures the authors routinely undertook to minimize the risk of humeral fracture during revision reverse shoulder arthroplasty. Several questions regarding the risk factors associated with intraoperative humerus fractures during revision reverse shoulder arthroplasty remain, including (1) What alternate humeral implant removal techniques, some previously described but not used by the authors in this study, could prevent certain intraoperative periprosthetic humerus fractures? (2) What prophylactic options are available to reduce the chances of humeral fracture during the phases of implantation? (3) What characteristics did untreated greater tuberosity fractures (˜90%) have in common and how did they differ from the ones that underwent adjunctive fixation? (4) How did prior instability, a complication often attributable to multiple causes, emerge as a significant risk factor for intraoperative humerus fracture? (5) What are the influences of instability direction and reducibility? It seems intuitive that the explantation of a terminally incarcerated cemented or cementless humeral prosthesis should have a higher rate of humerus fracture than one that is loose or less securely fixed. (6) Depending upon the composition of the cohort of patients under study, is it possible that the fracture rate, outcomes, and even risk factors might be at variance with the present study? (7) What factors other than porosity of bone render the female sex at higher risk for intraoperative fractures of the humerus during revision reverse shoulder arthroplasty? (8) Is it possible to take advantage of the humeral prosthesis for fracture fixation, and if so, what are those opportunities? How Do We Get There? A number of aspects of management and effect on outcomes should be elucidated. The authors have generously shared their results and established their institutional benchmark for the incidence and outcome of a particular complication of revision reverse shoulder arthroplasty. At this point, the risk factors that have been exposed are, at best, only superficially understood. Demographics, diagnosis, tissue properties and the postsurgical pathological state are immutable. A clearer picture of risk will hopefully emerge with a better understanding of their interrelationships in this setting. While an accounting of details of the surgical technical method is vital to the understanding of iatrogenic humerus fracture, the influence of the intangible virtues of patience, anticipation, caution, and judgment cannot be overlooked. For example, an investigation of intraoperative periprosthetic greater tuberosity fractures might take into account not only their location, pattern, intrinsic stability, soft-tissue attachments, and opportunities to optimize fixation to the bone and the adjacent prosthesis but also how particular treatment decisions are synthesized. Superior prosthetic instability usually accompanies shoulder prosthetic failures resulting from irreparable rotator cuff tear and is probably the most common instability pattern encountered during prosthetic revision. It is important that future investigations seeking to corroborate the results of the present study more clearly define the direction and status of prosthetic instability and how it may come to bear on the incidence and influence of intraoperative periprosthetic fractures. Humeral bone preservation at the time of revision reverse shoulder arthroplasty is the key to successful implantation of the revision humeral prosthesis. While aseptic prosthetic humeral loosening is rare, many current humeral prostheses for cemented and cementless usage are equipped with design geometry and surface enhancements to facilitate long-term fixation. Additional information will be gained from investigations that take into account specific features of the humeral prosthesis and the collateral damage to the humerus anticipated coincident to its explantation. Likewise, future studies should evaluate the utility of the so-called platform humeral prosthesis, which can be implanted at the time of the index (anatomic) total shoulder arthroplasty, but which can be converted later to a reverse total shoulder arthroplasty should the need arise. Such an implant potentially obviates the necessity for entire humeral component removal perhaps with less risk to the structural integrity of the humerus in the revision setting.

Cost-Effectiveness of Reverse Total Shoulder Arthroplasty Versus Arthroscopic Rotator Cuff Repair for Symptomatic Large and Massive Rotator Cuff Tears