Purpose. To evaluate the results of reverse total shoulder arthroplasty for complicated proximal humerus fractures in old ages. Materials and Methods. We retrospectively evaluated 13 cases who underwent reverse total shoulder arthroplasty for proximal humerus fracture, fracture-dislocation and nonunions of the fractures. Mean age was 77(68–87)years old and mean follow-up period was 15.2(12–26)months. four part fractures of proximal humerus in 7 cases, fracture-dislocation in 3 cases, locked dislocation with greater tuberosity in 2 cases, nonunion with defiency of rotator cuff in 1 case were included. We evaluated mean ASES, mean UCLA, mean KSS, mean SST and mean range of motion(ROM). Results. Postoperative mean ASES was 59(13–98.5), mean UCLA was 21(12–34), mean KSS was 62(21–94), mean SST was 5(1–11). Postoperative mean ROM was 103°(30°–135°) in forward flexion, 93°(30°–135°) in abduction, 21°(0°–45°) in external rotation and L4 level in internal rotation. The complications were not shown in any cases except for resolved heterotropic ossification. 4 cases demonstrated bony unions on greater tuberosity and 4 cases showed scapular notching on last follow-up. Conclusions. Reverse total shoulder arthroplasty for complicated proximal humerus fracture, nonunion of the fracture, or chronic locked dislocation seems to be a good treatment options. Regardless of bony union of the greater tuberosity, reverse total shoulder arthroplasty for the complicated proximal humerus fractures had a satisfied results

The treatment of rotator cuff arthropathy due to irreparable massive rotator cuff tear is still challenging. We performed reverse total shoulder arthroplasties for 2 cases of cuff tear arthropathy. The short term follow-up after the surgery reveal excellent results by ASES and UCLA score. However, these results still require long term follow-up and the study about implant design for the shoulder anatomy of the Koreans

Abstract. Objective. To investigate the safety and cost-effectiveness of interscalene brachial plexus block/regional anaesthesia (ISB-RA) in patients undergoing reverse total shoulder replacement. Methods. This retrospective study included 15 patients with symptomatic rotator cuff arthropathy who underwent reverse total shoulder arthroplasty (rTSA) under ISB-RA without general anaesthesia in the beach chair position from 2010 to 2018. The mean patient age was 77 years (range 59–82 years). Patients had associated medical comorbidities: American Society of Anesthesiologists (ASA) grade 2–4. Assessed parameters were: duration of anaesthesia, intra-operative systolic blood pressure variation, sedation and vasopressor use, duration of post-operative recovery, recovery scores, length of stay, and complications. A robust cost analysis was also performed. Results. The mean (range) duration of anaesthesia was 38.66 (20–60) min. Maximum and minimum intra-operative systolic blood pressure ranges were 130–210 and 75–145 mmHg, respectively (mean [range] drop, 74.13 [33–125] mmHg). Mean (range) propofol dose was 1.74 (1–3.0) mg/kg/h. The Median (interquartile range) post-operative recovery time was 30 (20–50) min. The mean (range) postoperative recovery score (local scale, range 5–28 where lower values are superior) was 5.2 (5–8). The mean (range) length of stay was 8 (1–20 days); the two included patients with ASA grade 2 were both discharged within 24 hours. One patient with predisposing history developed pneumonia; however, there were no complications related to ISB-RA. The mean (range) cost per patient was £101.36 (£59.80-£132.20). Conclusions. Our data demonstrate that rTSA under ISB-RA is safe, cost-effective and a potentially viable alternative for patients with multiple comorbidities. Notably, patients with ASA grade 2 who underwent rTSA under ISB-RA had a reduced length of stay and were discharged within 24 hours

Introduction & Aims. Over the last decade, sensor technology has proven its benefits in total knee arthroplasty, allowing the quantitative assessment of tension in the medial and lateral compartment of the tibiofemoral joint through the range of motion (VERASENSE, OrthoSensor Inc, FL, USA). In reversal total shoulder arthroplasty, it is well understood that stability is primarily controlled by the active and passive structures surrounding the articulating surfaces. At current, assessing the tension in these stabilizing structures remains however highly subjective and relies on the surgeons’ feel and experience. In an attempt to quantify this feel and address instability as a dominant cause for revision surgery, this paper introduces an intra-articular load sensor for reverse total shoulder arthroplasty (RTSA). Method. Using the capacitive load sensing technology embedded in instrumented tibial trays, a wireless, instrumented humeral trial has been developed. The wireless communication enables real-time display of the three-dimensional load vector and load magnitude in the glenohumeral joint during component trialing in RTSA. In an in-vitro setting, this sensor was used in two reverse total shoulder arthroplasties. The resulting load vectors were captured through the range of motion while the joint was artificially tightened by adding shims to the humeral tray. Results. For both shoulder specimens, the newly developed sensor provided insight in the load magnitude and characteristics through the range of motion. In neutral rotation and under a condition assessed as neither too tight nor too loose, glenohumeral loads in the range of 10–30lbs were observed. As expected, with increasing shim thickness these intra- articular load magnitudes increased. Assessing the load variations through the range of motion, high peak forces of up to 120 lbs were observed near the limits of the range of motion, most pronounced during external humeral rotation. Conclusions. In conclusion, this paper presents an intra-articular load sensor that can be used during the trialing phase in reverse total shoulder arthroplasty. A first series of cadaveric experiments provided evidence of realistic load ranges and load characteristics with respect to the end of the range of motion. Currently, effort is undertaken to develop a biomechanically validated load range that can serve as a target in surgery

Purpose:. To evaluate the results of reverse total shoulder arthroplasty for complicated proximal humerus fractures in old ages. Materials and Methods:. We retrospectively evaluated 13 cases who underwent reverse total shoulder arthroplasty for proximal humerus fracture, fracture-dislocation and nonunions of the fractures. Mean age was 77 years old and mean follow-up period was 15.2(12–26) months. four part fractures of proximal humerus in 7 cases, fracture-dislocation in 3 cases, locked dislocation with greater tuberosity in 2 cases, nonunion with defiency of rotator cuff in 1 case were included (Fig. 1, Fig. 2, Fig. 3). We evaluated mean ASES, mean UCLA, mean KSS, mean SST and mean range of motion (ROM). Results:. Postoperative mean ASES was 59(13–98.5), mean UCLA was 21(12–34), mean KSS was 62(21–94), mean SST was 5(1–11). Postoperative mean ROM was 103° in forward flexion, 93° in abduction, 21° in external rotation and L4 level in internal rotation. 4 cases demonstrated bony unions on greater tuberosity and 4 cases showed scapular notching on last follow-up. Conclusion:. Reverse total shoulder arthroplasty for complicated proximal humerus fracture, nonunion of the fracture, or chronic locked dislocation seems to be a good treatment options. Regardless of bony union of the greater tuberosity, reverse total shoulder arthroplasty for the complicated proximal humerus fractures had a satisfied results. Key words: Shoulder, Proximal humerus fracture, Reverse total shoulder arthroplasty

Glenoid bone grafting in reverse total shoulder arthroplasty (RTSA) has emerged as an effective method of restoring bone stock in the presence of complex glenoid bone loss, yet there is limited published evidence on efficacy. The aim of this study was to conduct an analysis of clinical and radiographic outcomes associated with glenoid bone grafting in primary RTSA. Patients who underwent a primary RTSA with glenoid bone grafting were retrospectively identified from the databases of two senior shoulder surgeons. Inclusion criteria included minimum of 12 months clinical and/or radiographical follow up. Patients underwent preoperative clinical and radiographic assessment. Graft characteristics (source, type, preparation), range of movement (ROM), patient-reported outcome measures (Oxford Shoulder Scores [OSS]), and complications were recorded. Radiographic imaging was used to analyse implant stability, graft incorporation, and notching by two independent reviewers. Between 2013 and 2021, a total of 53 primary RTSA procedures (48 patients) with glenoid bone grafting were identified. Humeral head autograft was used in 51 (96%) of cases. Femoral head allograft was utilised in two cases. Depending on the morphology of glenoid bone loss, a combination of structural (corticocancellous) and non-structural (cancellous) grafts were used to restore glenoid bone stock and the joint line. All grafts were incorporated at review. The mean post-operative OSS was significantly higher than the pre-operative OSS (40 vs. 22, p < 0.001). ROM was significantly improved post-operatively. One patient is being investigated for residual activity-related shoulder pain. This patient also experienced scapular notching resulting in the fracturing of the inferior screw. One patient experienced recurrent dislocations but was not revised. Overall, at short term follow up, glenoid bone grafting was effective in addressing glenoid bone loss with excellent functional and clinical outcomes when used for complex bone loss in primary RTSA. The graft incorporation rate was high, with an associated low complication rate

Currently, the consensus regarding subscapularis tendon repair during a reverse total shoulder arthroplasty (rTSA) is to do so if it is possible. Repair is thought to decrease the risk of dislocation and improve internal rotation but may also increase stiffness and improvement in internal rotation may be of subclinical benefit. Aim is to retrospectively evaluate the outcomes of rTSA, with or without a subscapularis tendon repair. We completed a retrospective review of 51 participants (25 without and 26 with subscapularis repair) who received rTSR by a single-surgeon using a single-implant. Three patient reported outcome measures (PROM) were assessed pre-operatively and post-operative at twelve months, as well as range of movement (ROM) and plain radiographs. Statistical analysis utilized unpaired t tests for parametric variables and Mann-Whitney U test for nonparametric variables. External Rotation ROM pre-operatively was the only variable with a significance difference (p=0.02) with the subscapularis tendon repaired group having a greater range. Pre- and post-operative abduction (p=0.72 & 0.58), forward flexion (p=0.67 & 0.34), ASES (p=0.0.06 & 0.78), Oxford (p=0.0.27 & 0.73) and post-operative external rotation (p=0.17). Greater external rotation ROM pre-operatively may be indicative of the ability to repair the subscapularis tendon intra-operatively. However, repair does not seem to improve clinical outcome at 12 months. There was no difference of the PROMs and AROMs between the subscapularis repaired and not repaired groups for any of the variables at the pre-operative or 12 month post operative with the exception of the external rotation ROM pre-operatively. We can conclude that from PROM or AROM perspective there is no difference if the tendon is repaired or not in a rTSR and indeed the patients without the repair may have improved outcomes at 12 months

Introduction. Reverse total shoulder replacement is performed for the treatment of rotator cuff arthropathy, massive irreparable cuff tears and failed shoulder hemiarthroplasty with irreparable rotator cuff tears. The aim of this study was to assess the clinical and radiological outcome of single surgeon series of Equinoxe® reverse total shoulder replacement at a district general hospital. Materials/Methods. Consecutive patients who underwent Equinoxe® reverse total shoulder replacement at our unit from Jun 2008 to Dec 2010 were retrospectively reviewed. Indications for surgery, complications and radiological outcomes were assessed. Oxford shoulder score was used to assess the functional outcome. Results. Between Jun 2008 and Dec 2012, forty-one reverse total shoulder replacements were performed by the senior author in 37 patients. Of these, Equinoxe® prostheses were used in 27 operations (26 patients). These included 22 female and 4 male patients. Cuff arthropathy was the commonest preoperative diagnosis (23 patients), followed by proximal humeral fracture non-union (2 patients), failed hemiarthroplasty (one patient) and failed resurfacing (one patient). The mean follow up was 10 months (3 to 17 months). At the time of the study, three patients had died due to unrelated causes, two were not contactable and the remaining 21 patients were analysed. The mean oxford shoulder score was 35.8 (21–48). Nineteen patients (90.5%) graded their outcome a good to excellent while 2 patients (9.5%) graded as poor. Seventeen patients (81%) expressed that they would recommend this operation. One patient (4.7%) had infection and another had dislocation. Overall, there were 3 reoperations (14.3%); first washout, second change of humeral tray and third excision of lateral end of clavicle and reattachment of deltoid. Two patients (9.5%) had small glenoid notching. There was no loosening, neurovascular injury or postoperative haematoma. Conclusion. Early outcome of Equinoxe reverse shoulder replacement is promising. Longer follow-up is required to further assess the outcome

Abstract. Background/Objectives. The incidence of reverse total shoulder replacement (rTSR) implantation is increasing globally, but apprehension exists regarding complications and associated challenges. We retrospectively analysed the senior author's series of rTSR from a tertiary centre using the VAIOS shoulder system, a modular 4th generation implant. We hypothesised that the revision rTSR cohort would have less favourable outcomes and more complications. Methods. 114 patients underwent rTSR with the VAIOS system, over 7 years. The primary outcome was implant survival. Secondary outcomes were Oxford shoulder scores (OSS), radiographic analysis (scapular notching, tuberosity osteolysis, and periprosthetic radiolucent lines) and complications. Results. There were 55 Primary rTSR, 31 Revision rTSR and 28 Trauma rTSR. Implant survival: Primary rTSR- 0 revisions, average 3.35-year follow-up. Revision rTSR-1 revision (4.17%), average 3.52-year follow-up. Trauma rTSR- 1 revision (3.57%), average 4.56-year follow-up OSS: Average OSS improved from 15.39 to 33.8 (Primary rTSR) and from 15.11 to 29.1 (Revision rTSR). Average post-operative OSS for the Trauma rTSR was 31.4 Radiological analysis and complications: Low incidence of scapular notching One hairline fracture below the tip of stem, noted incidentally, which required no treatment. One periprosthetic fracture after alcohol related fall. Treated non-surgically One joint infection requiring two-stage revision to rTSR. One dislocation noted at 2 year follow up. This patient had undergone nerve grafting within 6 months of rTSR for axillary nerve injury sustained during the original fracture dislocation. One acromial fracture with tibial and distal humeral fracture after a fall. Conclusions. The 4th generation modular VAIOS implant is a reliable option for various indications. The revision rTSR cohort had favourable outcomes with low complication rates. In this series, early-to-medium term results suggest lower revision rates and good functional outcomes when compared to published reports. We plan to monitor long-term implant survivorship and patient reported outcomes. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Introduction. Reverse total shoulder arthroplasty (RTSA) is rapidly being adopted as the standard procedure for a growing number of shoulder arthropathies. Though short-term outcomes are promising, mid- and long-term follow-ups present a number of complications – among them, humeral stem and glenosphere component loosening. Though not the primary complication, previously reported aseptic loosening required revision in 100% of cases. As the number of patients undergoing RTSA increases, especially in the younger population, it is important for surgeons to identify and utilize prostheses with stable long-term fixation. It has previously been shown in the hip and knee literature that implant migration in the first two years following surgery is predictive of later failure due to loosening in the 5=10-year postoperative window. The purpose of this study is to, for the first time, evaluate the pattern and total magnitude of implant migration in reverse shoulder arthroplasty using the gold standard imaging technique radiostereometric analysis (RSA). Methods. Forty patients were prospectively randomized to receive either a cemented or press-fit humeral stem, and a glenosphere secured to the glenoid with either autologous bone graft or 3D printed porous titanium for primary reverse total shoulder arthroplasty. Following surgery, participants are imaged using RSA, a calibrated, stereo x-ray technique. Radiographs are acquired at 6 weeks (baseline), 3 months, 6 months, 1 year, and 2 years. Migration of the humeral stem and glenosphere at each time point is compared to baseline. Migration of the prostheses is independently compared between humeral stem fixation groups and glenosphere fixation groups using a two-way repeated measures ANOVA with Tukey's test for multiple comparisons. Results. Follow-ups are ongoing and preliminary results are presented. Significant differences were observed at the 6-month and 1-year time points for superior-inferior translation (p = 0.0067, p = 0.0048), and total three-dimensional translation (p = 0.0011, p = 0.0272) between humeral stems, with press-fit humeral stems subsiding significantly more than cemented stems. Migration between the 6-month and 1-year time points was minimal for both stem fixation groups (less than 0.2 mm). No significant differences were observed along any axis at any time point for the glenosphere fixation groups. Conclusion. There is a trend towards increased subsidence with the use of press-fit stems compared to cemented stems in the first six months postoperatively, as is expected. Both implant fixation techniques demonstrate stability from six months through one year, and this trend is expected through two-year follow-up. Similarly, both glenosphere fixation techniques demonstrate immediate and stable fixation through one year

Aims of the study: To assess the results of one-stage revision of infected reverse total shoulder arthroplasty as a new treatment for this major surgical complication. Materials: 11 consecutive patients with infected reverse shoulder prosthesis (DePuy International Ltd, Leeds, UK) were treated with a direct-exchange reverse total shoulder arthroplasty between March 2005 and June 2007. These patients were retrospectively followed. Methods: Via a superior extended deltoideopectoral, clavicular osteotomy approach, according to Redfern-Wallace, a removal of the prosthesis is performed. Multiple operative specimens (4 to 8) are taken and cultured. A thorough synovectomy is performed before implanting a new reverse total shoulder arthroplasty (7 Delta. ®. 3.2 tsp and 4 DeltaXtend. ®. tsp). A gentamycine (Duracol. ®. ) impregnated membrane is interpositioned between baseplate and glenosphere. Immediate postoperative passive and active mobilisation is permitted if no pain is present. Results: Clinical symptoms are seldom severe pain (3) or severe limitation of function (3). A fistula is mainly present (8) without alterating the function. No prosthetic loosening was present at the humeral and glenoid site confirming the absence of radiological infectious signs. All but one patient are considered free of infection at mean follow up of 24 months (12m – 36m) and without antibiotic treatment for minimum 6 months. In only 1 patient the infection persisted necessitating a two-stage revision, unfortunately without definitive cure. Only three early complications are seen (< 2 months: posterior dislocation, postoperative haematoma and clavicle fracture). The mean postoperative Constant-Murley score was 52 (14–81) at latest follow up. Peroperative samples identified Propionbacterium species (5), Coagulase-negative staphylococci (4), MRSA (1) and with E.Coli (1) infection. Monobacterial infection was seen in 6 shoulders, multibacterial in 2 shoulders and in 2 shoulders cultures were negative. Discussion: This cohort of patients has a different syndrome than the known infected anatomical prosthesis. This pathology seems to be rarely associated with severe pain (3) or limitation of function (3). Draining fistulas without alterating the function of the shoulder [CS: mean 43 (3–63)] are more frequently present making a preoperative diagnosis easier and more certain. Recurrence rate of infection is comparable to the classical two-stage revision. Preoperative stiff and painful shoulders seems to have a bad prognosis despite definite cure of the infection. Supple shoulders (mainly associated with a fistula) can be treated with a good functional result. Conclusion: One-stage revision arthroplasty is an attractive alternative treatment for infected reverse total shoulder arthroplasty

The reverse total shoulder replacement (rTSR) has excellent clinical outcomes and prosthesis longevity, and thus, the indications have expanded to a younger age group. The use of a stemless humeral implant has been established in the anatomic TSR; and it is postulated to be safe to use in rTSR, whilst saving humeral bone stock for younger patients. The Lima stemless rTSR is a relatively new implant, with only one paper published on its outcomes. This is a single-surgeon retrospective matched case control study to assess short term outcomes of primary stemless Lima SMR rTSR with 3D planning and Image Derived Instrumentation (IDI), in comparison to a matched case group with a primary stemmed Lima SMR rTSR with 3D planning and IDI. Outcomes assessed: ROM, satisfaction score, PROMs, pain scores; and plain radiographs for loosening, loss of position, notching. Complications will be collated. Patients with at least 1 year of follow-up will be assessed. With comparing the early radiographic and clinical outcomes of the stemless rTSR to a similar patient the standard rTSR, we can assess emerging trends or complications of this new device. 41 pairs of stemless and standard rTSRs have been matched, with 1- and 2-year follow up data. Data is currently being collated. Our hypothesis is that there is no clinical or radiographical difference between the Lima stemless rTSR and the traditional Lima stemmed rTSR

Introduction. Total shoulder arthroplasty is the fastest growing joint replacement in recent years, with projected compound annual growth rates of 10% for 2016 through 2021 – higher than those of both the hip and knee combined. Reverse total shoulder arthroplasty (RTSA) has gained particular interest as a solution for patients with irreparable massive rotator cuff tears and failed conventional shoulder replacement, for whom no satisfactory intervention previously existed. As the number of indications for RTSA continues to grow, so do implant designs, configurations, and fixation techniques. It has previously been shown that continuous implant migration within the first two years postoperatively is predictive of later loosening and failure in the hip and knee, with aseptic loosening of implant components a guaranteed cause for revision in the reverse shoulder. By identifying implants with a tendency to migrate, they can be eliminated from clinical practice prior to widespread use. The purpose of this study is to, for the first time, evaluate the pattern and magnitude of implant component migration in RTSA using the gold standard imaging technique radiostereometric analysis (RSA). Methods. Forty patients were prospectively randomized to receive either a cemented or press-fit humeral stem, and a glenosphere secured to the glenoid with either autologous bone graft or 3D printed porous titanium (Aequalis Ascend Flex, Wright Medical Group, Memphis, TN, USA) for primary reverse total shoulder arthroplasty. Following surgery, partients are imaged using RSA, a calibrated, stereo x-ray technique, at 6 weeks (baseline), 3 months, 6 months, 1 year, and 2 years. Migration of the humeral stem and glenosphere at each time point is compared to baseline. Preliminary results are presented, with 15 patients having reached the 6-month time point by presentation. Results. Implant migration of ten participants at the 3-month time point is presented. Maximum total point motion (MTPM) is a measure of translation and rotation of the point on the implant that has moved the most from baseline. Average MTPM ± SD of the humeral stem is 1.18 ± 0.65 mm and 0.98 ± 0.46 mm for press-fit (n = 6) and cemented (n = 4) stems, respectively; and 0.25 ± 0.09 mm and 0.47 ± 0.24 mm for bone graft (n = 4) and porous titanium (n = 6) glenosphere fixations, respectively, at the 3-month time point. Conclusion. There is a trend towards increased migration with the use of press-fit humeral stems and porous titanium glenosphere fixation, though no conclusions can be made from the current sample size. Further, though differences in migration magnitude may be observed at early postoperative time points, it is expected that all fixation techniques will show stability from 1 to 2 years postoperatively

Glenoid baseplate positioning for reverse total shoulder replacements (rTSR) is key for stability and longevity. 3D planning and image-derived instrumentation (IDI) are techniques for improving implant placement accuracy. This is a single-blinded randomised controlled trial comparing 3D planning with IDI jigs versus 3D planning with conventional instrumentation. Eligible patients were enrolled and had 3D pre-operative planning. They were randomised to either IDI or conventional instrumentation; then underwent their rTSR. 6 weeks post operatively, a CT scan was performed and blinded assessors measured the accuracy of glenoid baseplate position relative to the pre-operative plan. 47 patients were included: 24 with IDI and 23 with conventional instrumentation. The IDI group were more likely to have a guidewire placement within 2mm of the preoperative plan in the superior/inferior plane when compared to the conventional group (p=0.01). The IDI group had a smaller degree of error when the native glenoid retroversion was >10° (p=0.047) when compared to the conventional group. All other parameters (inclination, anterior/posterior plane, glenoids with retroversion <10°) showed no significant difference between the two groups. Both IDI and conventional methods for rTSA placement are very accurate. However, IDI is more accurate for complex glenoid morphology and placement in the superior-inferior plane. Clinically, these two parameters are important and may prevent long term complications of scapular notching or glenoid baseplate loosening. Image-derived instrumentation (IDI) is significantly more accurate in glenoid component placement in the superior/inferior plane compared to conventional instrumentation when using 3D pre-operative planning. Additionally, in complex glenoid morphologies where the native retroversion is >10°, IDI has improved accuracy in glenoid placement compared to conventional instrumentation. IDI is an accurate method for glenoid guidewire and component placement in rTSA

Reverse Total shoulder arthroplasty (RTSA) was initially introduced to treat rotator cuff arthropathy. With proven successful long-term outcomes, it has gained a noteworthy surge in popularity with its indications consequently being extended to treating various traumatic glenohumeral diseases. Several countries holding national registries remain a guide to the use the prosthesis, however a notable lack of epidemiological data still exists. More so in South Africa where the spectrum of joint disease related to communicable diseases such as HIV and tuberculosis may influence indications and patient demographics. By analysing the epidemiology of patients who underwent RTSA at our institution, we aimed to outline the local disease spectrum, the patients afflicted and indications for surgery. A retrospective review of all patients operated within the sports unit between 1 January 2019 and 31 December 2022 was conducted. An analysis of the epidemiological data pertaining to patient demographics, diagnosis, indications for surgery and complications were recorded. Included in the review were 58 patients who underwent primary RTSA over the 4-year period. There were 41 females and 17 male patients, age <55 years (n= 14) >55 years (n=44). The indications included 23 rotator cuff arthropathy (40%), 12 primary glenohumeral osteoarthritis (OA) (20%), 10 avascular necrosis (AVN) humeral head (17%), 7 inflammatory OA (12%), 4 chronic shoulder dislocation (7%) and 2 sequalae of proximal humerus fractures (4%). The study revealed RTSA being performed in patients older than 55 years of age, the main pathologies included rotator cuff arthropathy and primary OA, however AVN and shoulder dislocations secondary to trauma contributed significantly to the total tally of surgeries undertaken. This highlights the disease burden of developing countries contributing to patients presenting for RTSA

Modern musculoskeletal modeling techniques have been used to simulate shoulders with reverse total shoulder arthroplasty and study how geometric changes resulting from implant placement affect shoulder muscle moment arms. These studies do not, however, take into account how changes in muscle length will affect the force generating capacity of muscles in their post-operative state. The goal of this study was to develop and calibrate a patient-specific shoulder model for subjects with RTSA in order to predict muscle activation during dynamic activities. Patient-specific muscle parameters were estimated using a nested optimization scheme calibrating the model to isometric arm abduction data at 0°, 45° and 90°. The model was validated by comparing predicted muscle activation for dynamic abduction to experimental electromyography recordings. A twelve-degree of freedom model was used with experimental measurements to create a set of patient-specific data (three-dimensional kinematics, muscle activations, muscle moment arms, joint moments, muscle lengths, muscle velocities, tendon slack lengths, optimal fiber lengths and peak isometric forces) estimating muscle parameters corresponding to each patient's measured strength. The optimization varied muscle parameters to minimize the difference between measured and estimated joint moments and muscle activations for isometric abduction trials. This optimization yields a set of patient-specific muscle parameters corresponding to the subject's own muscle strength that can be used to predict muscle activation and muscle lengths for a range of dynamic activities. The model calibration/optimization procedure was performed on arm abduction data for a subject with reverse total shoulder arthroplasty. Muscle activation predicted by the model ranged between 3% and 90% of maximum. The maximum joint moment produced was 20 Nm. The model replicated measured joint moments accurately (R2 > 0.99). The optimized muscle parameter set produced feasible muscle moments and muscle activations for dynamic arm abduction, when calibrated using data from isometric force trials. Current modeling techniques for the upper extremity focus primarily on geometric changes and their effects on shoulder muscle moment arms. In an effort to create patient-specific models, we have developed a framework to predict subject-specific muscle parameters. These estimated muscle parameters, in combination with patient-specific models that incorporate the patient's joint configurations, kinematics and bone anatomy, provide a framework to predict dynamic muscle activation in novel tasks and, for example, predict how joint center changes with reverse total shoulder arthroplasty may affect muscle function

Backgrounds. The rigid fixation of glenoid base plate is essential for the prevention of dissociation of the construct in the reverse total shoulder arthroplasty. For the rigid fixation, ideal placement of fixation screw is crucial but it is difficult to determine the best direction and length of screws. The purpose of this study was to determine configuration of optimal screw in cadaveric scapulae and compare with that in patient who underwent reverse total shoulder arthroplasty. Materials and methods. Seven scapulae were used and implanted using a variable angle base plate with four directions screws. Optimal screw placement was defined as that which maximized screw length, accomplished far cortical purchase. Insertion angle and length of every screw was measured from AP and axial radiograph taken after the screws fixation. In a similar manner, the insertion angles of screws were measured from radiographs of 7 postoperative patients who underwent reverse total shoulder arthroplasty. The averages of length and insertion angle of 4 screws from two groups were compared. Result. The average lengths of screws were anterior 29.4 mm, posterior 15.0 mm, superior 36.0 mm, inferior 46.7 mm in the cadavers group and 22.2 mm, 22.3 mm, 28.0 mm, 29.1 mm each in the patient group. There was statistical significance of the difference of the insertion angle of superior and inferior screws between two groups. Conclusion. Trajectory angles of superior and inferior screw were smaller than those of optimal screws. Awareness of this tendency is helpful to insert the optimal screws intraoperatively

Introduction. The purpose of this study was to compare implant survivorship and functional outcomes in patients undergoing reverse total shoulder arthroplasty (RTSA) for acute proximal humeral fracture (PHF) with those undergoing elective RTSA in a population-based cohort study. Methods. Prospectively collected data from the New Zealand Joint Registry from 1999 to 2021 and identified 7,277 patients who underwent RTSA. Patients were categorized by pre-operative indication, including acute PHF (10.1%), rotator cuff arthropathy (RCA) (41.9%), osteoarthritis (OA) (32.2%), rheumatoid arthritis (RA) (5.2%) and old traumatic sequelae (4.9%). The PHF group was compared with elective indications based on patient, implant, and operative characteristics, as well as post-operative outcomes (Oxford Shoulder Score [OSS], and revision rate) at 6 months, 5 and 10 years after surgery. Survival and functional outcome analyses were adjusted by age, sex, ASA class and surgeon experience. Results. Implant survivorship at 10 years for RTSA for PHF was 97.3%, compared to 96.1%, 93.7%, 92.8% and 91.3% for OA, RCA, RA and traumatic sequelae, respectively. When compared with RTSA for PHF, the adjusted risk of revision was higher for traumatic sequelae (hazard ratio = 2.29; 95% CI:1.12–4.68, p=0.02) but not for other elective indications. At 6 months post-surgery, OSS were significantly lower for the PHF group compared to RCA, OA and RA groups (31.1±0.5 vs. 35.6±0.22, 37.7±0.25, 36.5±0.6, respectively, p<0.01), but not traumatic sequelae (31.7±0.7, p=0.43). At 5 years, OSS were only significantly lower for PHF compared to OA (37.4±0.9 vs 41.0±0.5, p<0.01), and at 10 years, there were no differences between groups. Discussion and Conclusion. RTSA for PHF demonstrated reliable long-term survivorship and functional outcomes compared to other elective indications. Despite lower functional outcomes in the early post-operative period for the acute PHF group, implant survivorship rates were similar to patients undergoing elective RTSA

Reverse total shoulder arthroplasty (RTSA) has a proven track record as an effective treatment for a variety of rotator cuff deficient conditions. However, glenoid erosion associated with the arthritic component of these conditions can present a challenge for the shoulder arthroplasty surgeon. Options for treatment of glenoid wear include partial reaming with incomplete baseplate seating, bony augmentation using structural or impaction grafting techniques, and augmented baseplates. Augmented components have the advantage of accommodating glenoid deformity with a durable material and also ream less subchondral bone; both of which may offer an advantage over traditional bone grafting. Biomechanical and early clinical studies of augmented glenoid baseplates suggest they are a reasonable treatment option, though posteriorly augmented baseplates have shown better performance than superiorly augmented implants. However, there are no mid- or late-term studies comparing augmented baseplates to bone grafting or partial reaming. We present a live surgical demonstration of RTSA for a patient with advanced glenoid erosion being treated with an augmented glenoid baseplate that can be dialed in the direction of any deformity (superior, posterior, etc.). This versatility allows the surgeon to place the augment in any direction and is not confined to the traditional concepts of glenoid wear in a single vector. Clearly, longer term follow up studies are needed to determine the ultimate effectiveness of these devices in treating glenoid deformity in RTSA

We present a series of 18 consecutive cases of primary reverse total shoulder arthroplasty for irreparable proximal humerus fractures in patients over 70. Failure of tuberosity union and poor cuff function leads to unsatisfactory results in over half the patients with hemiarthroplasty. Reverse total shoulder arthroplasty does not depend upon a functional rotator cuff and requires little formal rehabilitation. Patients over 70 with irreparable proximal humerus fractures treated with a reverse total shoulder arthroplasty were included in this study. Only primary arthroplasties were included. Reverse arthroplasties for failed hemiarthroplasties were excluded. All arthroplasties were performed using either a deltoid split direct lateral (superior) approach or the antero-lateral MacKenzie approach. The SMR reverse total shoulder prothesis was implanted in all cases using a press-fit glenoid base plate and glenosphere, and press-fit or cemented humerus stem. Tuberosity repair was attempted in 10 cases. The supraspinatus was excised from the greater tuberosity. Patients were allowed self-mobilisation after two weeks in a sling. Patients were recruited and followed up per ethics approved protocol. Outcome measures used were range of motion, dislocation and revision rates radiological signs of loosening and glenoid notching, DASH and Constant scores. Results were compared to another series of cases of reverse shoulder arthroplasty for sequelae of trauma and failed hemiarthroplasties, as well as a series of primary hemiarthroplasties. At an average follow-up of 30 months (minimum 12 months) all patients were satisfied with their results. Average forward elevation was 132 deg. and abduction 108 deg. There was not deterioration of movement at 12 or 24 months. No patient had ongoing pain. The average constant score was 62. There was no evidence of humeral stem loosening apart from one case of early subsidence in a press fit stem. Eleven cases showed glenoid notching, four Nerot grade 1, six Nerot grade 2 and one Nerot grade 3. All notching had stabilised after 12 months. There were no cases of dislocation. No case needed revision, or awaits revision. All cases were pain-free at last review. Overall results for this group of primary reverse arthroplasties for fractures was much better than for reverse arthroplasties for sequelae of trauma. The results were also better than for primary hemiarthroplasties. Irreparable three and four part fractures of the proximal humerus pose management challenges in the elderly. The reverse total shoulder arthroplasty is very attractive option for elderly patients with irreparable proximal humerus fractures. They require little rehabilitation and can give reproducibly good functional results, which do not deteriorate with time