Introduction. The clinical impact of scapular notching is controversial. Some reports suggest it has no impact while others have demonstrated it does negatively impact clinical outcomes. The goal of this clinical study is to analyze the pre- and post-operative outcomes of 415 patients who received rTSA with one specific prosthesis (Equinoxe; Exactech, Inc). Methods. 415 patients (mean age: 72.2yrs) with 2 years minimum follow-up were treated with rTSA for CTA, RCT, and OA by 8 fellowship trained orthopaedic surgeons. 363 patients were deemed to not have a scapular notch by the implanting surgeon at latest follow-up (72.1 yrs; 221F/131M) whereas 52 patients were deemed to have a scapular notch at latest follow-up (73.3 yrs; 33F/19M). Outcomes were scored using SST, UCLA, ASES, Constant, and SPADI metrics; active abduction, forward flexion, and internal/external rotation were also measured to quantify function. Average follow-up was 38.1 months (No Notch: 37.2; Notch: 44.4). A two-tailed, unpaired t-test identified differences (p<0.05) in pre-operative, post-operative, and pre-to-post improvements. Results. The overall scapular notching rate was 12.5%. The rTSA cohort with a scapular notch had an average notching grade of 1.3 (41 grade 1, 6 grade 2, 5 grade 3, and 0 grade 4 notches). rTSA patients with a scapular notch on average weighed significantly less (168.0 vs. 154.7 lbs; p = 0.016) and had a significantly lower BMI (27.3 vs. 26.0; p = 0.032). 8 patients without scapular notching had a radiolucent line around the humeral component (2.2%); whereas, 5 patients with scapular notching had a radiolucent line around the humeral component (10.0%). Table 1 demonstrates no difference between the cohorts in pre-operative outcomes. Table 2 demonstrates rTSA patients without scapular notching were associated with significantly larger clinical outcome scores in all 5 metrics and also had significantly improved function according to 3 of the 6 measurements as compared to rTSA patients with scapular notching. Table 3 demonstrates only one significant difference was observed in pre-to-post improvement of outcome scores between cohorts. Finally, 27 complications were reported (6.5%), 20 for patients without scapular notching (5.5%) and 7 complications for patients with scapular notching (13.5%). Discussion and Conclusions. This large-scale clinical outcome study demonstrated that patients with scapular notching are associated with significantly poorer outcomes and a greater complication rate than patients without scapular notching at a similar average post-operative follow-up. The finding that patients with lower BMI were associated with a higher notching rate is new but also intuitive as these patients can likely adduct their arm more; it may also be that the lower average BMI and weight suggests that patients with notching were also more active. One additional new finding in this analysis is that patients with scapular notching had a 4.5X greater rate of radiolucent lines around the humeral component suggesting that the UHWMPE wear debris are related to the formation of humeral radiolucent lines. Additional and longer-term follow-up is needed to confirm these conclusions

Scapular notching is a common problem following reverse shoulder arthroplasty (RSA). This is due to impingement between the humeral polyethylene cup and scapular neck in adduction and external rotation. Various glenoid component strategies have been described to combat scapular notching and enhance impingement-free range of motion (ROM). There is limited data available detailing optimal glenosphere position in RSA with an onlay configuration. The purpose of this study was to determine which glenosphere configurations would maximise impingement free ROM using an onlay RSA prosthesis. A three-dimensional (3D) computed tomography (CT) scan of a shoulder with Walch A1, Favard E0 glenoid morphology was segmented using validated software. An onlay RSA prosthesis was implanted and a computer model simulated external rotation and adduction motion of the virtual RSA prosthesis. Four glenosphere parameters were tested; diameter (36mm, 41mm), lateralization (0mm, 3mm, 6mm), inferior tilt (neutral, 5 degrees, 10 degrees), and inferior eccentric positioning (0.5mm, 1.5mm. 2.5mm, 3.5mm, 4.5mm). Eighty-four combinations were simulated. For each simulation, the humeral neck-shaft angle was 147 degrees and retroversion was 30 degrees. The largest increase in impingement-free range of motion resulted from increasing inferior eccentric positioning, gaining 15.0 degrees for external rotation and 18.8 degrees for adduction. Glenosphere lateralization increased external rotation motion by 13. 6 degrees and adduction by 4.3 degrees. Implanting larger diameter glenospheres increased external rotation and adduction by 9.4 and 10.1 degrees respectively. Glenosphere tilt had a negligible effect on impingement-free ROM. Maximizing inferior glenosphere eccentricity, lateralizing the glenosphere, and implanting larger glenosphere diameters improves impingement-free range of motion, in particular external rotation, of an onlay RSA prosthesis. Surgeons’ awareness of these trends can help optimize glenoid component position to maximise impingement-free ROM for RSA. Further studies are required to validate these findings in the context of scapulothoracic motion and soft tissue constraints

Despite the high success rates of Reverse Shoulder replacements, complications of instability & scapular notching are a concern. Factors reducing relative motion of implant to underlying bone which include lateral offset to centre of rotation, screw & central peg insertion angle and early osteo-integration are maximized in the Trabecular Metal Reverse total shoulder system. We present clinico-radiological outcomes over 72 months. Analysis of a single surgeon series of 140 Reverse total shoulder replacements in 135 patients was done. Mean age was 72(range 58– 87 yrs); 81 females: 54 males. Indications were Rotator cuff arthropathy {n= 88} (63%); Osteo-arthritis with dysfunctional cuff {n= 22}(15%); post-trauma{n=23} (15%); revision from hemiarthroplasty {n=3} (2.4%) and from surface replacement {n=4} (2.8%). All patients were assessed using pre-operative Constants and Oxford scores and clinical & radiographic reviews with standard X-Rays at 6 weeks, 3, 6,12 months and yearly thereafter. X rays included an AP view in 45 degrees of external rotation and modified axillary view. Inferior Scapular notching using the Nerot-Sirveaux grades and Peg Glenoid Rim Distance were looked into by a consultant musculoskeletal radiologist/ Orthopaedic surgeon/ Senior Fellow (post CCT) or a specialist Trainee (ST4 and above). Pain on the visual analogue scale decreased by 98% (9.1 to 0.8) (p<0.01). Constant score improved by 81.8% (12.4 to 68.1) (p<0.05), Oxford shoulder score by 76.7% (56 to 13) (p<0.05). 95.6% of Humeral stems had no radiolucent lines and 4.4% had < 2mm of lucency. Scapular notching was calculated using Sirveaux grades with Peg scapular base angle distance (PSBA) measurements on PACS with Siemens calibration (grade 1= 4 (2.8%); grade 2 =1; grade 3 =0; grade 4=0). 3.57% showed radiographic signs of scapular notching at 72 months. Range of Peg Glenoid Rim Distance was 1.66 to 2.31 cm. Power analysis showed 65 patients were needed to have an 80% power to detect relation of Peg Glenoid Rim Distance to Scapular notching. A likelihood ratio test from Logistic regression model to check correlation of Peg Glenoid Rim Distance to Scapular notching gave a p value of 0.0005. A likelihood ratio from Logistic regression gave a p value of 0.0004 for Infraglenoid Scapular spurs. Highest incidence of spurring was seen in Reverse Total Shoulder Replacements done for Trauma and lowest in patients who got the procedure for Osteoarthritis. Complications included two glenosphere revisions; two stitch abscesses and two Acromial fractures in patients who had a fall two years after the procedure. Improved surgical outcomes can be attributed to surgical technique and implant characteristics. Trabacular metal promotes early osteointegration which resists shearing action of Deltoid on Glenoid component. This allows early mobilisation. Deltoid split approach preserves integrity of Subscapularis and Acromial osteotomy and lateral clavicle excision improve exposure and prevent Acromion fracture. Positioning the Glenoid component inferiorly on the Glenoid decreases incidence of Scapular notching. Our mid-term validated outcomes are promising with only 3.57% Grade I/II radiographic signs of scapular notching. Long term studies (10 year follow ups) are necessary to confirm its efficacy

Background. One of the main concern about reverse shoulder arthoplasty for the treatment of rotator cuff deficiency is scapular notching that is still an unsolved issue for this particular prosthesis. The purpose of this multicentric retrospective study is to compare two different concept of reverse prosthesis, one with a concentric glenoshere and the other one with a new eccentric glenoshere design that aim to minimize scapular notching. Methods. From 2004 to 2009 67 patients were treated with a SMR reverse shoulder prosthesis (LIMA) with either concentric (figure 2) or eccentric glenosphere (figure 1). We selected for the study patients with criteria as much homogeneous as possible by the age and pathology. We then included for the study 25 patients (Group 1) with a concentric glenosphere and 21 (Group 2) with a eccentric glenosphere. All baseplates of concentric glenospheres were implanted with the most inferior aspect of baseplate that matched with the inferior glenoid ream, so that the glenosphere extended 4 mm beyond the glenoid inferiorly in order to minimize scapular notching. Every patient were followed clinically (Constant and Murley Score [C.S.] and Simple Shuolder test [S.S.T.]) and radiographically (notching, loosening and mechanical failure) with a minimum follow-up of 24 months. We also evaluated at the final follow-up psna (prosthesis-scapular neck angle), pgrd (peg glenoid rim distance) and DBSNG (distance between scapular neck and glenosfere). Results. At two years of follow up R.O.M. increased significantly in both groups especially in those with a eccentric glenosphere. Notably in patients with an eccentric glenosphere elevation improved from 66° to 148° and abduction from 60° to 115° while in those with a concentric glenosphere improved from 78° to 122° and 71° to 98° respectively for elevation and abduction. Outcomes for external-rotation and internal-rotation were very similar in both groups. 14 (56%) patients among those with a concentric glenosphere had scapular notching while we didn't have any notch in those with eccentric glenosphere even though we didn't find any significant different between the two groups in term of clinical outcomes and patient's satisfaction. The average C.S. increased from 38% to 69% in those with concentric SMR and from 30% to 74% in the other group. At the final follow-up PSNA, DBSNG and PGRD were respectively 88°, 3,2mm and 18,2 mm in group 1, while they were 92°, 4,3 mm and 21,2 mm in the group 2. Conclusions. Putting concentric glenosphere more inferiorly reduce the incidence of scapular notching but it doesn't solve the problem whereas, at medium follow-up, the new eccentric design seems to solved completely this issue. This study sustains PSNA, DBSNG, PGRD as reliable measures to predict scapular notching. Besides eccentric SMR glenosphere seems to increase R.O.M. mostly in flexion, abduction and adduction

Reverse shoulder arthroplasty is becoming a frequent treatment of choice for patients with shoulder disorders. Complication rates after reverse shoulder arthroplasty may be three-fold that of conventional total shoulder arthroplasty especially in high risk patient populations and diagnoses like revision arthroplasty, fracture sequelae, and severe glenoid bone loss. Complications include component malposition, stiffness, neurological injury, infection, dislocation or instability, acromial or scapular spine fractures, scapular notching, and loosening of implants. Recognition of preoperative risk factors and appropriate 3D planning are essential in optimizing patient outcome and intraoperative success. Failure of reverse shoulder arthroplasty is a significant challenge requiring appropriate diagnosis of the failure mode. The most common neurological injuries involve the brachial plexus and the axillary nerve due to traction, manipulation of the arm, aberrant retractor placement, or relative lengthening of the arm. Intraoperative fractures are relatively uncommon but include the greater tuberosity, acromion, and glenoid. Tuberosity fracture can be repaired intraoperatively with suture techniques, glenoid fractures may be insignificant rim fractures or jeopardise baseplate fixation and require abandoning RSA until glenoid fracture ORIF heals and then a second stage RSA. Periprosthetic infection after RSA ranges from 1 to 10% and may be higher in revision cases and frequently is Propionibacterium acnes and Staphylococcus epidermidis. Dislocation was one of the most common complications after RSA approximately 5% but with increased surgeon experience and prosthetic design, dislocation rates are approaching 1–2%. An anterosuperior deltoid splitting approach has been associated with increased stability as well as subscapularis repair after RSA. Scapular notching is the most common complication after RSA. Notching may be caused by direct mechanical impingement of the humerosocket polyethylene on the scapular neck and from osteolysis from polyethylene wear. Sirveaux classified scapular notching based on the defect size as it erodes behind the baseplate towards the central post. Acromial fractures are infrequent but more common is severely eroded acromions from CTA, with osteoporosis, with excessive lengthening, and with superior baseplate screws that penetrate the scapular spine and create a stress riser. Nonoperative care is the mainstay of acromial and scapular spine fractures. Recognizing preoperative risk factors and understanding component positioning and design is essential to maximizing successful outcomes

Purpose. Reverse shoulder prosthesis may lead to scapular notching, caused by attrition of the upper humeral component with scapular neck. We compared the clinical and radiographic results obtained with a SMR prosthesis, which allows a concentric or an eccentric glenosphere to be applied. Patients and methods. 67 patients, mean age 73 years, were treated with reverse prosthesis using concentric and eccentric glenosphere. In patients with concentric glenosphere, the glenosphere extended about 4 mm below the glenoid. The eccentric glenosphere protected the upper glenoid neck by its inferior prolongment. Patients were followed for a mean of 33 months. At final F-U the Constant Score (C.S.) and the score with the Simple Shoulder test (S.S.T.) were calculated. Radiographs were obtained to evaluate the presence of scapular notching, psna (prosthesis-scapular neck angle), pgrd (peg- glenoid rim distance) and DBSNG (distance between scapular neck and glenosfere). Included in this study were patients, as much homogeneous as possible by age and pathology, 25 with concentric (Group I) and 30 with eccentric (Group II) glenosphere, who had a minimum F-U of 24 months. Statistical analysis was performed with a paired test. Results. 25 patients of group I and 26 in group II were available for the study. In Group I mean elevation improved from 78° to 122° and mean abduction from 71° to 98°; in Group II from 66° to 148° and 60° to 115°. External and internal rotations were similar in both groups. 14 (56%) patients of Group I, and none of Group II had scapular notching (p<0.001). CS increased from 38 pt to 69 pt in Group I and from 30 pt to 74 pt in Group II. Conclusions. Low implantation of glenosphere did not eliminate scapular notching. Instead, no notching was detected with eccentric glenosphere, which also increased the ROM. The PSNA, DBSNG, PGRD are reliable measures to predict scapular notching

Background. Scapular notching is a complication after reverse shoulder arthroplasty with a high incidence up to 100%. Its clinical relevance remains uncertain; however, some studies have reported that scapular notching is associated with an inferior clinical outcome. There have been no published articles that studied positional relationship between the scapular neck and polyethylene insert in vivo. The purpose of this study was to measure the distance between the scapular neck and polyethylene insert in shoulders with Grammont type reverse shoulder arthroplasty during active external rotation at the side. Methods. Eighteen shoulders with Grammont type prosthesis (Aequalis Reverse, Tornier) were enrolled in this study. There were 13 males and 5 female, and the mean age at surgery was 74 years (range, 63–91). All shoulders used a glenosphere with 36mm diameter, and retroversion of the humeral implant was 10°in 4 shoulders, 15°in 3 shoulders, and 20°in 11 shoulders. Fluoroscopic images were recorded during active external rotation at the side from maximum internal to external rotation at the mean of 14 months (range, 7–24) after surgery. The patients also underwent CT scans, and three-dimensional glenosphere models with screws and scapula neck models were created from CT images. CT-derived models of the glenosphere and computer-aided design humeral implant models were matched with the silhouette of the implants in the fluoroscopic images using model-image registration techniques (Figure 1). Based on the calculated kinematics of the implants, the closest distance between the scapular neck and polyethylene insert was computed using the scapular model and computer-aided design insert models (Figure 2). The distance was computed at each 5° increment of glenohumeral internal/external rotation, and the data from 20°internal rotation to 40°external rotation were used for analyses. One-way repeated-measures analysis of variance was used to examine the change of the distance during the activity, and the level of significance was set at P < 0.05. Results. The mean glenohumeral abduction during the activity was 17°-22°. The mean distance between the neck and insert was approximately 1mm throughout the activity (Figure 3). The distance tended to become smaller with the arm externally rotated, but the change was not significant. Discussion. The reported incidence of scapular notching after Grammont type reverse shoulder arthroplasty is generally higher than the newer design prosthesis with the lateralized center of rotation. This may be associated with the design of the prosthesis, and the results of this study that the distance between the neck and insert was approximately 1mm throughout active external rotation at the side will support the high incidence of notching. We may need to analyze the distance with the newer design reverse shoulder prosthesis to prove the architectural advantage of the newer systems. Conclusion. The distance between the scapular neck and polyethylene insert was approximately 1mm throughout active external rotation activity in shoulders with Grammont type prosthesis

Background. There has been increased focus on understanding the risk factors associated with scapular notching in reverse shoulder arthroplasty (RSA). The purpose of this study is to evaluate the effect of scapular morphology and surgical technique on the occurrence of scapular notching using the notching index as a comprehensive predictive tool. Methods. Ninety-one patients treated with a primary RSA were followed for a minimum of 24 months. Using a previously published notching index formula ((PSNA × 0.13) + (PGRD)), a notching index value for all patients was calculated. Radiographic assessment of patients were grouped by Nerot grade of scapular notching, group mean differences for prosthetic scapular neck angle (PSNA), peg glenoid rim distance (PGRD), preoperative scapular neck angle (SNA), notching index and clinical outcomes were compared. Results. Seventy-five (82%) of the ninety one shoulders in the study developed scapular notching. There was no significant difference in average notching index for group 1, 31.8 ± 4.4, and group 2, 33.1 ± 7.2. No significant difference was demonstrated between the groups for SNA (102.7° vs. 105.4°, p = 0.3), PSNA (125.8° vs. 124.5°, p = 0.82), PGRD (15.4 mm vs. 16.8 mm, p = 0.47) or in clinical outcomes between groups. Discussion. Our results demonstrated an overall low notch index that lacked specificity in predicting notching for this cohort. These results suggest that perhaps PSNA and prosthetic design are more significant contributors to notching with certain scapular morphology

Introduction. Due to the predictability of outcomes achieved with reverse shoulder arthroplasty (rTSA), rTSA is increasingly being used in patients where glenoid fixation is compromised due to presence of glenoid wear. There are various methods to achieve glenoid fixation in patients with glenoid wear, including the use of bone grafting behind the glenoid baseplate or the use of augmented glenoid baseplates. This clinical study quantifies clinical outcomes achieved using both techniques in patients with severe glenoid wear at 2 years minimum follow-up. Methods. 80 patients (mean age: 71.6yrs) with 2 years minimum follow-up were treated by 7 fellowship trained orthopaedic surgeons using rTSA with bone graft behind the baseplate or rTSA with an augmented glenoid baseplate in patients with severe posterior glenoid wear. 39 rTSA patients (14 female, avg: 73.1 yrs; 25 male, avg: 71.5 yrs) received an augmented glenoid (cohort composed of 24 patients with an 8° posterior augment baseplate and 15 patients with a 10° superior augment baseplate) for treatment of CTA, RCT, and OA with a medially eroded scapula. 41 rTSA patients (27 female, avg: 73.0 yrs; 14 male, avg: 66.9 yrs) received glenoid bone graft (cohort composed of 5 patients with allograft and 36 patients with autograft) for treatment of CTA, RCT, and OA with a medially eroded scapula. Outcomes were scored using SST, UCLA, ASES, Constant, and SPADI metrics; active abduction, forward flexion, and internal/external rotation were also measured to quantify function. Average follow-up was 31.2 months (augment 28.3; graft 34.1). A two-tailed, unpaired t-test identified differences (p<0.05) in pre-operative, post-operative, and pre-to-post improvements. Results. A comparison of pre-operative, post-operative, and pre-to-post improvement in outcomes are presented in Tables 1–3, respectively. No difference was noted in pre-operative, post-operative, and pre-to-post improvement in outcomes between cohorts. The augmented glenoid baseplate rTSA cohort had 0 complications for a complication rate of 0%; whereas, the rTSA glenoid bone graft cohort had 6 complications (including 2 glenoid loosenings/graft failures) for a complication rate of 14.6%. Additionally, radiographic follow-up information was available for 30 of 39 augmented baseplate patients (76.9%) and 27 of 41 bone graft patients (65.9%); where the augmented baseplate rTSA cohort had a scapular notching rate of 10.0% with an average scapular notching grade of 0.1; whereas, the rTSA glenoid bone graft cohort had a scapular notching rate of 18.5% with an average scapular notching grade of 0.19. Conclusions. These results demonstrate positive outcomes can be achieved at 2 years minimum follow-up in patients with severe glenoid wear using either augmented glenoid baseplates or bone graft behind the glenoid baseplate with rTSA. While no statistical difference was noted between pre-operative, post-operative, and pre-to-post improvement in outcomes between rTSA cohorts, a substantial difference in the complication rate was noted between cohorts which may factor into the surgeon's decision of the choice of treatment technique for these patients. Additional and longer-term follow-up is needed to confirm these outcomes and trends

Introduction. Reverse shoulder prosthesis has been developed to treat the clinical and pathological condition noted as cuff tear arthropathy (CTA). The current models of reverse shoulder arthroplasty (RSA) expose the procedure to the risk of scapular notching, possibly leading to loosening of the glenoid. Aim. The purpose of this study was to report updated results at a minimum follow-up of four years of 25 patients underwent reverse shoulder arthroplasty between 2006 and 2010 with an eccentric 36-mm glenoid component (SMR Lima). Methods. Clinical and radiographic evaluation was performed preoperatively and at every year of follow-up. All patients were evaluated with MRI or CT scan preoperatively and with X-ray examinations postoperatively to evaluate the presence of inferior scapular notching. To value the clinical outcome the Constant score and VAS score have been evaluated preoperatively and every year of follow up. Results. Since the last report the mean Constant remain stable (63.11±8.92) and the mean VAS score decreased to 1.75±2.38 (p<0.005). Radiographs showed one case of grade 1 inferior scapular notching at 7-year follow-up. Notching didn't have any influence on clinical outcome. In two patients radiolucent lines were visible around the central peg or screws. No patient had glenoid baseplate loosening or baseplate failure. Conclusion. Satisfactory results have been achieved in the treatment of cuff-deficient shoulder conditions with reverse shoulder arthroplasty using an eccentric glenosphere at medium follow up. The patients have maintained their improved function with durable clinical and radiographic results at a minimum of four years

Introduction. A common phenomenon occurring as a result of reverse total shoulder arthroplasties (RSA) is scapular notching. While bone loss of the scapula may be quantified using radiographic techniques,[1] the material loss on the humeral bearing has not been quantified. Depending on their functional biological activity, a high volume of polyethylene wear particles has been shown to be related to osteolysis, bone loss and ultimately, loosening of implants in other joints.[2] In order to understand the threshold for osteolysis in the shoulder, it is important to have a method that can accurately quantify the amount of material loss. The aim of this research was to (I) create and validate a method for quantifying material loss from a single humeral implant design which can then (II) be used to measure retrieved devices. Methods. Measurement of the surface topography of the implant was completed using coordinate measurement machine (CMM). The resulting point cloud was then imported into MATLAB and run through a custom algorithm to determine the volumetric wear of the humeral liner. Two never implanted humeral liners with an artificially damaged material loss were used for validation purposes. Each component was scanned three times, analyzed using the custom MATLAB program, and compared to gravimetric analysis (Figure 1). Following validation, an IRB-approved database was queried to identify 10 retrieved components of the same design which were then analyzed using the validated method. Results. All average measurements of the never implanted components were within +/- 5 mm. 3. of the gravimetrically determined values, providing a reasonable estimate of the volumetric wear (Figure 1). Ten retrieved components of a single design were analyzed using the same method and material loss ranged from immeasurable (within the accuracy limits) to approximately 90 mm. 3. (Figure 3). One short term duration implant (1.8 mos) exhibited approximately 78 mm. 3. of wear, resulting in a polyethylene dosage of more than 500 mm. 3. /yr. Discussion. The posterior-inferior wear pattern on the rim of these reverse shoulders appears consistent with repetitive scapular impingement. The significant wear of short duration implants indicates that wear associated with scapular notching may progress very quickly, resulting in large dose rates of debris in the joint space. However, the impingement may result in a more abrasive wear mechanism as opposed to an adhesive wear mechanism as seen in other joint wear environments. This may result in different size and shaped polyethylene particles with different biological activity. The algorithms presented in this work can be used to establish a dose-response relationship for scapular notching in RSA

Abstract. Reverse shoulder arthroplasty (RSA) is being increasingly used for complex, displaced fractures of the proximal humerus. The main goal of the current study was to evaluate the functional and radiographic results after primary RSA of three or four-part fractures of the proximal humerus in elderly patients. Between 2012 and 2020, 70 consecutive patients with a recent three- or four-part fracture of the proximal humerus were treated with an RSA. There were 41 women and 29 men, with a mean age of 76 years. The dominant arm was involved in 42 patients (60%). All surgeries were carried out within 21 days. Displaced three-part fracture sustained in 16 patients, 24 had fracture dislocation and 30 sustained a four-part fracture of the proximal humerus. Patients were followed up for a mean of 26 months. The mean postoperative OSS at the end of the follow-up period was 32.4. The mean DASH score was 44.3. Tuberosity non-union occurred in 18 patients (12.6%), malunion in 7 patients (4.9%), heterotopic ossification in 4 patients (2.8%) and scapular notching in one patient. Anatomical reconstruction was achieved in 25 patients (17.5%), the influence of greater tuberosity healing on shoulder function could not be demonstrated. Heterotopic ossification seems to affect OSS and QDASH, we found statistically significant relation between HO and clinical outcomes. Patients with heterotopic ossification had significantly lower postoperative scores on DASH and OSS (P = .0527). Despite expecting good functional outcome with low complication rate after RSA, the functional outcome was irrespective of healing of the tuberosities

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

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 shoulder arthroplasty (RSA) has an increasing effective use in the treatment of patients with a variety of diagnoses, including rotator cuff deficiency, inflammatory arthritis, or failed shoulder prostheses. Glenoid bone loss is not uncommonly encountered in these cases due to the significant wear. Severe bone loss can compromise glenoid baseplate positioning and fixation, consequently increasing the risk for early component loosening, instability, and scapular notching. To manage severe glenoid bone deficiencies, bone grafts are commonly used. Although, many studies report outcome of bone grafting in revision RSA, the literature on humeral head autograft for glenoid bone loss in primary RSA is less robust. The purpose of this study is to evaluate the clinical and radiographic outcomes of primary RSA with humeral head autograft for glenoid bone loss at our institution. Institutional review board approval was obtained to retrospectively review the records of 22 consecutive primary RTSA surgeries in 21 patients with humeral head autograft for glenoid bone loss between January 2008 and December 2016. Five patients died during follow-up, three were unable to be contacted and one refused to participate, leaving a final study cohort of 12 patients with 13 shoulders that underwent RSA. All patients had a clinical evaluation including detailed ROM and clinical evaluation using the American Shoulder and Elbow Surgeons (ASES) Score, Constant Score, Western Ontario Osteoarthritis of the Shoulder Index (WOOS), and Short Form-12 (SF-12) questionnaires. Preoperative and postoperative plain radiographs and CT scans were assessed for component position, loosening, scapular notching, as well as graft incorporation, resorption, or collapse. There were 6 males and 6 females, with an average age of 74 ± 6.8 years. The average BMI was 31.7 ± 5.3, and the median ASA score was 3. Average follow-up was 3.4 ± 1.1 years. The average postoperative range of motion measurements for the operative arm are: flexion = 120 ± 37, abduction = 106 ± 23, external rotation = 14 ± 12, internal rotation at 90 degrees of abduction = 49 ± 7, external rotation at 90 degrees of abduction = 50 ± 28. Average functional scores are: ASES: 76.9 ± 19.2, WOOS: 456 ± 347, SF12 physical: 34.2 ± 8.2, SF12 mental: 54.1 ± 10.2, Constant Score: 64.6 ± 14. No evidence of hardware loosening or evidence of bone graft resorption were encountered. On CT, the average of pre operative B-angle was 79.3 ± 9.3 while the pre operative reverse shoulder angle was 101.4 ± 28. Glenoid retroversion average on CT was 13.3 ± 16.6. Post operative baseplate inclination average was 82 ± 7.4 while the baseplate version 7.8 ±10. The operative technique was able to achieve up to 30 degrees of inclination correction and up to 50 degrees of version correction. In conclusion, primary reverse shoulder arthroplasty with humeral head autograft for glenoid bone loss provides excellent ROM and functional outcomes at mid-term follow-up. This technique has a high rate of bone incorporation and small risk of bone resorption at mid term follow up

Introduction:. Lateralization of reversed shoulder arthroplasty provides improvement in range of motion and decreases inferior scapular notching. The purpose of this study was to verify if the autologous cancelous bone graft harvested from the humeral head does heal constantly in a large cohort of patients followed for a long time. Methods:. Cohort of 92 consecutive patients operated between 2006 and 2010 with a BIORSA for definitive shoulder pseudoparalysis, secondary to cuff tear arthropathy (CTA) or massive, irreparable cuff tear (MCT). The autogenous cancelous graft was harvested from humeral head in all cases. Eight patients were lost for follow up, and four died before 2 years. The remaining 80 patients underwent clinical, radiographic and CT assessment at a minimum FU of 24 months. Mean age was 73 years. Three independent observers evaluated notching, partial or total glenoid or humeral loosening and viability of the graft. Constant-Murley score, range of motion and subjective shoulder value (SSV) were recorded. The mean follow up was 39 months (range 24–74 months). Results:. The bone graft did healed completely in 96% of the cases (77/80); the thickness of the graft remained stable through the years. There were two cases of glenoid loosening: one nonunion of the graft at the scapular side was due to an important superior tilt of the glenosphere; one failure of fixation at the baseplate side was related to a low-grade infection. Another patient had a partial radiolucent line between graft and native glenoid located only above the central peg. No other radiolucent line around peg, screws or baseplate was found. Inferior scapula notching was observed in 19% of the cases (mainly grade 1 and 2). Each parameters of Constant score improved, and the mean SSV increased from 27% to 78%. Conclusion:. This study shows that: (1) autologous cancellous bone graft, harvested from the humeral head, does heal to the native glenoid despite the advanced age of the patients; and (2) BIO-RSA allows improvement of shoulder function (mobility, pain, strength, subjective value) with a low rate of scapular notching

Purpose:. Although short term outcomes of reverse total shoulder arthroplasty (rTSA) have been promising, long-term success may be limited due to complications, including scapular notching. Scapular notching has been explained primarily as a mechanical erosion, however, generation of wear debris may lead to further biologic changes contributing to the severity of scapular notching. Highly cross-linked ultra-high molecular weight polyethylene (UHMWPE) has been used routinely in constrained joint applications such as total hip arthroplasty for reduction of wear debris particles. Although rTSA shares similarity in design conformity, conventional UHMWPE remains the gold standard. Methods:. A commercially available hip simulator was converted to a 12-station rTSA wear simulator. Conventional and highly cross-linked UHMWPE humeral liners were subjected to 5,000,000 cycles of alternating abduction-adduction and flexion-extension loading profiles. Every 250,000 cycles, liners were evaluated with gravimetric wear measurements and test serum was collected for morphological characterization of wear particles. Results:. Highly cross-linked UHMWPE liners (36.5 ± 10.0 mm. 3. /million cycle) exhibited significantly lower volumetric wear rates compared to conventional UHMWPE liners (83.6 ± 20.6 mm3/million cycle) (p < 0.001) (Figure 1). The flexion-extension loading profile exhibited significantly higher wear rates for both conventional (p < 0.001) and highly cross-linked UHMWPE (p < 0.001) compared to the abduction-adduction loading profile. Highly cross-linked wear particles had an equivalent circle diameter significantly smaller than wear particles from conventional UHMWPE (p < 0.001) (Figure 2). Highly cross-linked wear particles were also significantly less fibrillar than conventional UHMWPE particles with respect to particle aspect ratio (p < 0.001) and particle roundness (p < 0.001). Conclusion:. This is the first study to examine the effect of cross-linked PE in a rTSA wear simulation. Highly cross-linked UHMWPE liners significantly reduced UHWMPE wear and subsequent particle generation. More favorable wear properties with the use of highly cross-linked UHMWPE may lead to increased rTSA device longevity and fewer complications but must be weighed against the impact of reduced mechanical properties

Thoracic hyperkyphosis (TH – Cobb angle >40°) is correlated with rotator cuff arthropathy and associated with anterior tilting and protraction of scapula, impacting the glenoid orientation and the surrounding musculature. Reverse total shoulder arthroplasty (RTSA) is a reliable surgical treatment for patients with rotator cuff arthropathy and recent literature suggests that patients with TH may have comparable range of motion after RTSA. However, there exists no study reporting the possible link between patient-reported outcomes, humeral retroversion and TH after RTSA. While the risk of post-operative complications such as instability, hardware loosening, scapular notching, and prosthetic infection are low, we hypothesize that it is critical to optimize the biomechanical parameters through proper implant positioning and understanding patient-specific scapular and thoracic anatomy to improve surgical outcomes in this subset of patients with TH. Patients treated with primary RTSA at an academic hospital in 2018 were reviewed for a two-year follow-up. Exclusion criteria were as follows: no pre-existing chest radiographs for Cobb angle measurement, change in post-operative functional status as a result of trauma or medical comorbidities, and missing component placement and parameter information in the operative note. As most patients did not have a pre-operative chest radiograph, only seven patients with a Cobb angle equal to or greater than 40° were eligible. Chart reviews were completed to determine indications for RTSA, hardware positioning parameters such as inferior tilting, humeral stem retroversion, glenosphere size/location, and baseplate size. Clinical data following surgery included review of radiographs and complications. Follow-up in all patients were to a period of two years. The American Shoulder and Elbow Surgeons (ASES) Shoulder Score was used for patient-reported functional and pain outcomes. The average age of the patients at the time of RTSA was 71 years old, with six female patients and one male patient. The indication for RTSA was primarily rotator cuff arthropathy. Possible correlation between Cobb angle and humeral retroversion was noted, whereby, Cobb angle greater than 40° matched with humeral retroversion greater than 30°, and resulted in significantly higher ASES scores. Two patients with mean Cobb angle of 50° and mean humeral retroversion 37.5° had mean ASES scores of 92.5. Five patients who received mean humeral retroversion of 30° had mean lower ASES scores of 63.7 (p < 0 .05). There was no significant correlation with glenosphere size or position, baseplate size, degree of inferior tilting or lateralization. Patient-reported outcomes have not been reported in RTSA patients with TH. In this case series, we observed that humeral stem retroversion greater than 30° may be correlated with less post-operative pain and greater patient satisfaction in patients with TH. Further clinical studies are needed to understanding the biomechanical relationship between RTSA, humeral retroversion and TH to optimize patient outcomes

BACKGROUND:. Bony increased-offset reverse shoulder arthroplasty (BIO-RSA) creates a long-necked scapula, providing the benefits of lateralization. Experience with allogenic bone grafting of the glenoid in shoulder arthroplasty is mainly based on its use with total shoulder arthroplasty (TSA). Therefore, our study objectives were: 1) verify if the use of BIO-RSA together with glenoid surface grafting with allogenic bone would provide similar benefits (clinical and functional) as found with autologous bone, 2) determine if allograft could be a good alternative in the absence of (good quality) autograft bone, and 3) to see if the allograft would incorporate with the native glenoid bone. METHODS:. We included 25 patients (19 female, 6 male) in this prospective study. Indications for BIO-RSA were: fracture sequalle (n = 9), revisions (n = 11), 4-part humerus fracture (n = 1), rheumatoid arthritis (n = 1) and cuff tear arthropathy (CTA) with poor humeral head bone quality/osteonecrosis (n = 3). Mean (± SD) age 70 ± 11 years (range, 44–86). Clinical evaluation consisted of ROM, Constant scores, patient satisfaction (Subjective Shoulder Value (SSV)) and noted complications. Radiographic and CT scan evaluation consisted of bone graft healing, bone graft resorption/lysis, glenoid component loosening, inferior scapular notching, spur formation and anterior/posterior scapular notching. Mean follow-up was 34 ± 10 months (24–62). RESULTS:. Mean active mobility improved from 50 ± 39° to 123 ± 33° (50–170°) for anterior elevation, from 2.4 ± 17° to 12.1 ± 16° (−20–40°) for external rotation, and from 1.8 ± 2 to 4.7 ± 3 points (0–8) for internal rotation. Mean Constant scores improved from 19 ± 12 to 55 ± 16 points (30–83) and from 26 ± 16% to 77 ± 24% (40–111%). Mean SSV from 21 ± 16% to 65 ± 18% (30–100%). One patient sustained an acromial fracture (treated conservatively) and one patient had breakage of screws and complete glenoid component loosening (revised to a hemi arthroplasty). In 92% of cases (23 of 25) the allograft incorporated completely, partial lysis of the bone graft (n = 5), inferior scapular notching (n = 5), spur formation (n = 7), posterior notching (n = 5). CONCLUSIONS:. BIO-RSA with allograft bone grafting does not provide the same clinical and functional results as with autologous bone grafting. However, it does provide a good alternative in cases where humeral bone stock is not preserved and the allograft bone does incorporate with the native glenoid bone

Knowledge of the premorbid glenoid shape and the morphological changes the bone undergoes in patients with glenohumeral arthritis can improve surgical outcomes in total and reverse shoulder arthroplasty. Several studies have previously used scapular statistical shape models (SSMs) to predict premorbid glenoid shape and evaluate glenoid erosion properties. However, current literature suggests no studies have used scapular SSMs to examine the changes in glenoid surface area in patients with glenohumeral arthritis. Therefore, the purpose of this study was to compare the glenoid articular surface area between pathologic glenoid cavities from patients with glenohumeral arthritis and their predicted premorbid shape using a scapular SSM. Furthermore, this study compared pathologic glenoid surface area with that from virtually eroded glenoid models created without influence from internal bone remodelling activity and osteophyte formation. It was hypothesized that the pathologic glenoid cavities would exhibit the greatest glenoid surface area despite the eroded nature of the glenoid and the medialization, which in a vault shape, should logically result in less surface area. Computer tomography (CT) scans from 20 patients exhibiting type A2 glenoid erosion according to the Walch classification [Walch et al., 1999] were obtained. A scapular SSM was used to predict the premorbid glenoid shape for each scapula. The scapula and humerus from each patient were automatically segmented and exported as 3D object files along with the scapular SSM from a pre-operative planning software. Each scapula and a copy of its corresponding SSM were aligned using the coracoid, lateral edge of the acromion, inferior glenoid tubercule, scapular notch, and the trigonum spinae. Points were then digitized on both the pathologic humeral and glenoid surfaces and were used in an iterative closest point (ICP) algorithm in MATLAB (MathWorks, Natick, MA, USA) to align the humerus with the glenoid surface. A Boolean subtraction was then performed between the scapular SSM and the humerus to create a virtual erosion in the scapular SSM that matched the erosion orientation of the pathologic glenoid. This led to the development of three distinct glenoid models for each patient: premorbid, pathologic, and virtually eroded (Fig. 1). The glenoid surface area from each model was then determined using 3-Matic (Materialise, Leuven, Belgium). Figure 1. (A) Premorbid glenoid model, (B) pathologic glenoid model, and (C) virtually eroded glenoid model. The average glenoid surface area for the pathologic scapular models was 70% greater compared to the premorbid glenoid models (P < 0 .001). Furthermore, the surface area of the virtual glenoid erosions was 6.4% lower on average compared to the premorbid glenoid surface area (P=0.361). The larger surface area values observed in the pathologic glenoid cavities suggests that sufficient bone remodelling exists at the periphery of the glenoid bone in patients exhibiting A2 type glenohumeral arthritis. This is further supported by the large difference in glenoid surface area between the pathologic and virtually eroded glenoid cavities as the virtually eroded models only considered humeral anatomy when creating the erosion. For any figures or tables, please contact the authors directly