Objective: This study evaluates the preoperative conventional anteroposterior radiography in non-operated patients with cuff tear arthropathy. It analyses the radiological findings in relation to the status of the rotator cuff and clinical outcome. The aim of the study is to define the usefulness of this radiographical examination in cuff tear arthropathy. Methodology: This study analyses the preoperative radiological (AP-view, (Artro-)CT-scan or MRI-scan) and clinical characteristics (Constant-Murley-score plus active and passive mobility testing) and the peroperative findings in a cohort of 315 patients of which 282 had eccentric omarthrosis according to the classification of Hamada and 33 patients with centered omarthrosis who have at least two irreparable tendon tears. Those patients were part of a multicenter, retrospective, consecutive study of the French Orthopaedic Society (SOFCOT-2006). All patients had no surgical antecedents and were all treated with prosthetic shoulder surgery for a painful irreparable cuff tear arthropathy (reverse -(84%) or hemi-(8%) or double cup prosthesis (8%)). Results: Fatty degeneration of a rotator cuff muscle decreases its strength (p < 0.0001). In the presence of tendons lesser bony wear is seen at the acromion (acetabularisation, (p< 0.005), the glenoid (superomedial wear p=0.005) as well as the humeral head (femoralization, p=0.002). The radiological classifications according to Hamada and Favard seem not to be as appropriate to reflect accurately the location and extent of the tendino-muscular degeneration as the acromial acetabularization and humeral sphericity. The acromio-humeral distance is a good indicator for the location and the extend of the cuff tear arthropathy. A smaller acromio-humeral distance (95% CI: 4mm + 1) is only present if the postero-superior muscles are fatty degenerated (Goutallier stade III & IV) and a larger distance is calculated (95% CI: 7mm + 3) when only the antero-superior muscles are diseased. The coracoid tip in cuff tear arthropathy-patients is almost always positioned in the inferior half of the glenoid (84%). A bigger supero-inferior distance of the glenoid in relation to the radius of the humeral head indicates more structural destruction of rotator cuff status (tendinous and muscular) and a worse clinical outcome. Conclusion: This study defines the use of a conventional radiological antero-posterior view to evaluate eccentric omarthrosis as very useful. The direction of eccentricity in the scapular plane of the body and type of wear, situated either at the glenoïd, acromion or humeral head are determined by the location and extent of the tendinous lesion and the degree of fatty degeneration of the rotator cuff muscle

Most common current surgical treatment options for cuff tear arthropathy (CTA) are hemiarthroplasty and reverse total shoulder replacement. At our unit we have been using Reverse Total shoulder replacement (TSR) for CTA patients since 2001. We present our results of Reverse TSR in 64 patients (single surgeon) with a mean follow up of 2 years (Range 1 to 8 years). There were 45 males and 19 females in the study with a mean age of 70 years. Preoperative and postoperative Constant scores were collected by a team of specialist shoulder physiotherapists. Preoperatively plain radiographs were used to evaluate the severity of arthritis and bone stock availability. 90% patients showed an improvement in the Constant score post operatively. The mean improvement in Constant score was 25 points. The mean Pain Score (max 15) improved from 6.3 to 11.8; the mean ADL Score (max 20) improved from 6.8 to 12.3; the mean Range of Motion score (max 40) improved from 10.8 to 20.2; but the mean Power Score (max 25) only improved from 0.9 to 4.9. The differences in improvement were statistically significant in each category. A total 6 patients (10%) required 10 revision surgeries for various reasons. Two patients dislocated anteriorly who were treated by open reduction. Two patients required revision of the glenoid component due to loosening after a mean of 2 years. One patient required revision of the humeral component with strut grafting secondary to severe osteolysis. Only one patient required revision of both humeral and glenoid components secondary to malpositioning. Three patients died for reasons unconnected with their shoulder problems and surgery. Radiographic analysis at the latest follow up (mean 24 months) showed inferior glenoid notching in 40% cases. Heterotrophic ossification was not seen in our series. We conclude that reverse TSR is a viable option for treatment of cuff tear arthropathy however glenoid loosening and scapular notching remains an issue

Progressive arthritis can occur in association with massive tears of the rotator cuff. Altered joint kinematics are commonly proposed as the principle causative factor but this does not explain the absence of arthropathy in some patients. We have investigated the role of the ANKH gene in patients with cuff tear arthropathy. The transmembrane protein ANKH promotes intracellular to extracellular inorganic pyrophosphate channelling which regulates calcium pyrophosphate dihydrate and hydroxyapatite crystal deposition. Genomic DNA was prepared from peripheral blood leucocytes from 20 patients with cuff tear arthropathy diagnosed clinically and radiologically and 24 healthy matched controls. All 12 exons and exon-intron boundaries from the ANKH gene were PCR amplified and sequenced with BigDye version 3.1 terminator kit (ABI), and analysed using ABI PRISM ® 3100 Genetic Analyser. We have identified 5 single nucleotide polymorphisms (SNPs) including 4 that have previously been identified in patients with chondrocalcinosis. These are in exon 2 (GCC†’GCT 294), intron 2 (G†’A +8), exon 8 (GCA†’GCG 963) and intron 8 (T†’G +15). We also identified an A†’G variant in 3′-UTR, 30 base pairs after the stop codon which has not been reported before in crystal deposition diseases, and is also not seen in any of the healthy controls. Further elucidation is necessary to demonstrate a causal relationship between these ANKH mutations and cuff tear arthropathy, which will add to our understanding of pathogenic mechanisms in this condition

Before reverse shoulder replacement was an option for rotator cuff tear arthropathy the treatment modalities were limited to injections and physical therapy for pain control, arthroscopic debridement with or without biceps tenodesis/tenotomy and hemiarthroplasty. Functional improvement was limited with these treatment options and success for pain control was moderate at best. The destructive nature of the rotator cuff deficient shoulder continued with medialization of the glenoid and erosion of the acromion seen even after replacement with hemiarthroplasty. The end result usually left the patient with a pseudo paralysis of the shoulder region functionally and uncontrolled pain that made later revision with a reverse implant difficult or impossible. Reverse arthroplasty was released for use in United States in 2004 for rotator cuff tear arthropathy. This initial procedure had a number of related complications that have been improved on over time with changes in implant design and better operative techniques. The long term results with reverse total shoulder arthroplasty have made this the procedure of choice for contained cuff tear arthropathy

The combination of an irreparable tear of the rotator cuff and destructive arthritis of the shoulder joint may cause severe pain, disability and loss of independence in the aged. Standard anatomical shoulder replacements depend on a functioning rotator cuff, and hence may fail in the presence of tears in the cuff. Many designs of non-anatomical constrained or semi-constrained prostheses have been developed for cuff tear arthropathy, but have proved unsatisfactory and were abandoned. The DePuy Delta III reverse prosthesis, designed by Grammont, medialises and stabilises the centre of rotation of the shoulder joint and has shown early promise. This study evaluated the mid-term clinical and radiological results of this arthroplasty in a consecutive series of 50 shoulders in 43 patients with a painful pseudoparalysis due to an irreparable cuff tear and destructive arthritis, performed over a period of seven years by a single surgeon. A follow-up of 98% was achieved, with a mean duration of 39 months (8 to 81). The mean age of the patients at the time of surgery was 81 years (59 to 95). The female to male ratio was 5:1. During the seven years, six patients died of natural causes. The clinical outcome was assessed using the American Shoulder and Elbow score, the Oxford Shoulder Score and the Short-form 36 score. A radiological review was performed using the Sirveaux score for scapular notching. The mean American Shoulder and Elbow score was 19 (95% confidence interval (CI) 14 to 23) pre-operatively, and 65 (95% CI 48 to 82) (paired t-test, p < 0.001) at final follow-up. The mean Oxford score was 44 (95% CI 40 to 51) pre-operatively and 23 (95% CI 18 to 28) (paired t-test, p < 0.001) at final follow-up. The mean maximum elevation improved from 55° pre-operatively to 105° at final follow-up. There were seven complications during the whole series, although only four patients required further surgery

Background. Cuff tear arthropathy represents a challenging problem to the shoulder arthoplasty surgeon. Poor results of conventional total shoulder arthroplasty in cuff deficient shoulders due to glenoid component loosening have meant hemiarthroplasty has been the traditional preferred option. Recently reverse total shoulder arthroplasty (RSA) has gained increasing popularity due to a clinical perception of an improved functional outcome. This is despite the lack of comparative data, particularly in relation to modern hemiarthroplasty prostheses. The aim of this study was to compare the early functional results of Hemiarthroplasty versus RSA in the management of cuff-tear arthropathy. Material and Methods. Patients were identified from the New Zealand National Joint Registry and matched for age, sex, and American Society of Anesthesiologists scores.102 primary hemiarthroplasties performed for cuff tear arthropathy were compared with 102 RSAs performed for the same diagnosis. Oxford shoulder scores (OSS) were collected prospectively at 6 months and five years post operatively together with mortality and revision rates. Results. There were 51 males and 51 females in each group, with a mean age of 71.6 in the Hemiarthroplasty group and 72.6 in the RSA group. The mean ASA score was 2.2 in both groups. The median OSS was 31.1 in the hemiarthroplasty group and 41.1 in the RSA group. This difference was maintained at five years. At follow up, there were 7 revisions in the hemiarthroplasty group and 5 in the RSA group. No difference in mortality was seen between the two groups. Conclusion. This study provides the first direct evidence of improved functional outcome of RSA compared to Hemiarthroplasty in patients with cuff tear arthropathy. Longer-term follow up is needed to confirm that the improved function is maintained and that complications such as component loosening remain comparable

Cuff tear arthropathy represents a challenge to the shoulder arthoplasty surgeon. The poor results of conventional total shoulder arthroplasty in cuff deficient shoulders secondary to glenoid component loosening have meant hemiarthroplasty has traditionally been the preferred surgical option. Recently reverse total shoulder arthroplasty (RSA) has gained increasing popularity due to a clinical perception of an improved functional outcome, despite the absence of comparative data. The aim of this study was to compare the early functional results of Hemiarthroplasty versus RSA in the management of cuff-tear arthropathy. 102 primary hemiarthroplasties performed for cuff tear arthropathy were compared against 102 RSAs performed for the same diagnosis. Patients were identified from the New Zealand National Joint Registry and matched for age, sex, and American Society of Anesthesiologists (ASA) scores. Oxford shoulder scores (OSS) were collected at 6 months and 5 years post operatively and were compared between the two groups, together with mortality and re-revision rates. There were 51 males and 51 females in each group, with a mean age of 71.6 in the Hemiarthroplasty group and 72.6 in the RSA group. The mean ASA score was 2.2 in both groups. The mean OSS was 31.1 in the hemiar-throplasty group and 38.1 in the RSA group. At follow up, there were 7 revisions in the hemiarthroplasty group and 5 in the RSA group. No difference in mortality was seen between the two groups. This study provides the first direct evidence of a improved functional outcome of RSA compared to Hemiarthroplasty in the treatment of patients with cuff tear arthropathy. Longer term follow up is needed to confirm that the improved function is maintained, and that late complications such as component loosening remain comparable between the two groups

Cuff Tear Arthropathy is characterised by massive rotator cuff tears, glenohumeral joint destruction and joint effusions containing basic calcium phosphate and calcium pyrophosphate dihydrate crystals. We have investigated the role of the ANKH gene in patients with cuff tear arthropathy and the effect of mutations on protein function. The transmembrane protein ANKH transports inorganic pyrophosphate (PPi) from the intracellular to extracellular space. Control of the extracellular levels of PPi is crucial in preventing calcium crystal formation. Genomic DNA was prepared from peripheral blood leucocytes from 22 patients with cuff tear arthropathy diagnosed clinically and radiologically. All 12 exons and exon-intron boundaries from the ANKH gene were PCR amplified and sequenced with BigDye version 3.1 terminator kit (ABI), and analysed using ABI PRISM ® 3100 Genetic Analyser. ANKH complementary DNA (cDNA) was ligated with mammalian expression vector pcDNA3 and site directed mutagenesis was used to make the ANKH mutation detected in the cases. Human articular chondrocytes were transfected with the cDNA variants and PPi concentrations measured. A G-to-A single nucleotide polymorphism in the 3′ untranslated region (3′UTR) of ANKH was identified. The G/A genotype was seen more frequently in the cases (45%) when compared to controls (20%) (p= 0.0008). We observed altered levels of extracellular PPi in human chondrocytes transfected with ANKH cDNA with the 3′ UTR variant when compared with control cells and normal ANKH cDNA. Cuff Tear Arthropathy appears to be heritable via a G-to-A transition in the 3′UTR of ANKH that alters extracellular PPi concentrations in chondrocyte cells. This supports a hypothesis of a primary crystal mediated arthropathy in patients with Cuff Tear Arthropathy

We present a retrospective analysis of 50 cases of cuff tear arthropathy, treated over past seven year period by use of reverse geometry shoulder prosthesis. 98% follow-up was achieved with average follow up of 3 years. Mean (SD) age was 81.3 (9.2) years and female to male ratio was 5:1. Six patients had bilateral reverse geometry shoulder replacements. Patients were assessed with preoperative Oxford and American Shoulder and Elbow Scores Society score (pre-op ASES) and post-operative American Shoulder and Elbow Society Score (post-op ASES), Oxford, Constant and SF36 scores. Mean pre-op ASES was 22.29 (95%CI: 9.1 – 37.9) and post-op ASES score was 65.2 (95%CI: 48.5 – 81.9), (P< 0.001, Paired t-test). Mean post operative Oxford score was 27.25 (95% CI: 18.4 – 27.6). Mean post operative Constant score was 63.2 (95% CI: 52.6 – 79.6). X-ray review was performed to assess scapular notching and Sirveaux score was used to grade extent of notching. 11 patients had Sirveaux grade 0, 5 had grade 1, 6 had grade 2, 12 had grade 3 and 8 had grade 4 notching. Intra-operative complications included 2 glenoid fractures. Post-operative complications included 2 acromion fractures and 2 episodes of subsidence with dislocation. None of the patients developed post operative haematoma. There was one episode of infection in one patient that required further surgery. Iteration of approach with increasing experience over the years will be discussed. Ours is the biggest series of reverse geometry prosthesis used for irreparable rotator cuff tear arthropathy published so far in the literature and our results have shown superior results in terms of improvement in function and complications. We conclude reverse geometry shoulder replacement provides reasonable improvement in pain and function in elderly population with massive cuff tear arthropathy of shoulder

We present a retrospective analysis of 50 cases of cuff tear arthropathy, treated over a seven year period by use of reverse geometry shoulder prosthesis. 98% follow-up was achieved with average follow up of 3 years. Mean (SD) age was 81.3 (9.2) years and female to male ratio was 5:1. Six patients had bilateral reverse geometry shoulder replacements. Patients were assessed with pre-operative American Shoulder and Elbow Score (pre-op ASES) and post-operative American Shoulder and Elbow Scores (post-op ASES), Oxford, Constant and SF36 scores. Mean pre-op ASES was 22.29 (95%CI: 9.1 – 37.9) and post-op ASES score was 65.2 (95%CI: 48.5 – 81.9), (P< 0.001, Paired t-test). Mean post operative Oxford score was 27.25 (95% CI: 18.4 – 27.6). Mean post operative Constant score was 63.2 (95% CI: 52.6 – 79.6). X-ray review was performed to assess scapular notching and Sirveaux score was used to grade extent of notching. 11 patients had Sirveaux grade 0, 5 had grade 1, 6 had grade 2, 12 had grade 3 and 8 had grade 4 notching. Intra-operative complications included 2 glenoid fractures. Post-operative complications included 2 acromion fractures and 2 episodes of subsidence with dislocation. None of the patients developed post operative haematoma. There was one episode of infection in one patient that required further surgery. Iteration of approach with increasing experience over the years will be discussed. Ours is the biggest series of reverse geometry prosthesis used for irreparable rotator cuff tear arthropathy published so far in the literature and our results have shown superior results in terms of improvement in function and complications. We recommend reverse geometry shoulder replacement is the way forward to treat irreparable cuff tear arthropathy of shoulder

Background. Degeneration of the shoulder joint is a frequent problem. There are two main types of shoulder degeneration: Osteoarthritis and cuff tear arthropathy (CTA) which is characterized by a large rotator cuff tear and progressive articular damage. It is largely unknown why only some patients with large rotator cuff tears develop CTA. In this project, we investigated CT data from ‘healthy’ persons and patients with CTA with the help of 3D imaging technology and statistical shape models (SSM). We tried to define a native scapular anatomy that predesignate patients to develop CTA. Methods. Statistical shape modeling and reconstruction:. A collection of 110 CT images from patients without glenohumeral arthropathy or large cuff tears was segmented and meshed uniformly to construct a SSM. Point-to-point correspondence between the shapes in the dataset was obtained using non-rigid template registration. Principal component analysis was used to obtain the mean shape and shape variation of the scapula model. Bias towards the template shape was minimized by repeating the non-rigid template registration with the resulting mean shape of the first iteration. Eighty-six CT images from patients with different severities of CTA were analyzed by an experienced shoulder surgeon and classified. CT images were segmented and inspected for signs of glenoid erosion. Remaining healthy parts of the eroded scapulae were partitioned and used as input of the iterative reconstruction algorithm. During an iteration of this algorithm, 30 shape components of the shape model are optimized and the reconstructed shape is aligned with the healthy parts. The algorithm stops when convergence is reached. Measurements. Automatic 3D measurements were performed for both the healthy and reconstructed shapes, including glenoid version, inclination, offset and critical shoulder angle. These measurements were manually performed on the mean shape of the shape model by a surgeon, after which the point-to-point correspondence was used to transfer the measurements to each shape. Results. The critical shoulder angle was found to be significantly larger for the CTA scapulae compared to the references (P<0.01). When analyzing the classified scapulae significant differences were found for the version angle in the scapulae of group 4a/4b and the critical shoulder angle of group 3 when compared to the references (P<0.05). Conclusion. Patients with CTA have a larger critical shoulder angle compared with reference patients. Some significant differences are found between the scapulae from patients in different stages of CTA and healthy references, however the differences are smaller than the accuracy of the SSM reconstruction. Therefore, we are unable to conclude that there is a predisposing anatomy in terms of glenoid version, inclination or offset for CTA

Background. Absence of rotator cuff allows unbalanced muscle forces of the shoulder to cause vertical migration of the humeral head. The translation of the humerus causes impaction of articular surface against the acromion. The purpose of the study is to assess outcome of Cuff tear arthropathy (CTA) Hemiarthroplasty prosthesis in this group of patients. Methods. Retrospective review was undertaken in 42 patients who underwent Global CTA Hemiarthroplasty between Jan 2001-Jan 2009. The mean length of follow up was 6 years. Results. The patients at review showed statistically significant improvement in Forward Flexion, Abduction and Numerical Pain Rating. There were four revision surgeries and the overall survival rate at ten years was 89 %. There was statistically significant improvement (p < 0.05) in forward flexion abduction and Numerical rating scale (p 0.02). Although improvement was noted in external and internal rotation this was not statistically significant. There was one perioperative humerus fracture which required plating at the same time of surgery. The fracture went on to heal uneventfully. There was also one post-operative haematoma which required arthroscopic washout. One patient underwent further arthroscopic debridement for poor ROM which improved from 20 Abd 20 FF to 90, 90 FF, Abd. There were four revision surgeries; 3 revisions to reverse geometry replacement; and one patient had removal of implant because of persistant dislocation of implant and patient did not want another major surgery. Patients who required revision had further erosion of acromion and poor ROM of < 20 Abd, FF, and Pain 8–10/10. Conclusion. This study shows that significant improvement in pain, and movements are achieved with this device. Acromial and glenoid erosion is a potential issue with this prosthesis and three revisions were required for this this problem. The results are better than standard hemiarthroplasty when used in this setting

We present a retrospective review of 50 cases of cuff tear arthropathy treated over past seven years by the use of reverse geometry shoulder prosthesis. 98% follow-up was achieved with average follow up of 3.04 years. Mean age was 81.3 (SD 9.2) years, female to male ratio was 5:1 and seven patients had bilateral procedures. Pre-operatively patients were assessed with American Shoulder and Elbow Surgeons Scores (ASES) and Oxford Scores and pos-operatively with ASES, Oxford and Constant scores. SF36 score was used to assess functional health status. Mean pre-op ASES was 22.29 (95%CI: 9.1 – 37.9) and post-op ASES score was 65.2 (95%CI: 48.5 – 81.9), (P< 0.001, Paired t-test). Mean post-operative Oxford score was 27.25 (95% CI: 18.4 – 27.6) and mean post operative Constant score was 63.2 (95% CI: 52.6 – 79.6). Sirveaux score was used to grade extent of glenoid notching on AP and lateral glenohumeral views, that showed 69% had notched. Complications included two acromion fractures, two episodes of subsidence with dislocation, one episode of infection and one patient with unexplained pain in axilla. We found reverse geometry shoulder replacement provides reasonable improvement in pain and function in elderly patients with massive cuff tear arthropathy

This pilot study reports the clinical outcomes of a combination of partial subscapularis tendon transfer and small-head hemiarthroplasty in patients with rotatator cuff arthropathy. A total of 30 patients (30 shoulders; eight men and 22 women) with a mean age of 74 years (55 to 84) were assessed at a mean follow-up of 31 months (24 to 60). The inclusion criteria were painful cuff tear arthropathy with normal deltoid function and a non-degenerative subscapularis muscle and tendon and a preserved teres minor.

Outcome was assessed using the University of California Los Angeles score, the Japanese Orthopaedic Association score, and the Oxford Shoulder Score. Radiographic measurements included the centre of rotation distance and the length of the deltoid.

All clinical scores were significantly improved post-operatively. The active flexion and external rotation improved significantly at the most recent follow-up (p < 0.035). Although the mean centre of rotation distance changed significantly (p < 0.001), the mean length of the deltoid did not change significantly from the pre-operative value (p = 0.29). The change in the length of the deltoid with < 100° flexion was significantly less than that with > 100° (p < 0.001).

Progressive erosion of the glenoid was seen in four patients. No patient required revision or further surgery.

A combination of partial subscapularis tendon transfer and small-head hemiarthroplasty effectively restored function and relieved pain in patients with rotator cuff arthropathy.

Cite this article: 2015;97-B:1090–5.

Cementless surface replacement arthroplasty (CSRA) is an established treatment for glenohumeral osteoarthritis. Few studies however, evaluate its role in cuff tear arthopathy. The purpose of this study is to compare the outcomes of CSRA for both glenohumeral osteoarthritis and cuff tear arthopathy.

42 CSRA with the Mark IV Copeland prosthesis were performed for glenohumeral osteoarthritis (n=21) or cuff tear arthopathy (n=21). Patients were assessed with Oxford and Constant scores, patient satisfaction, range of motion and radiologically with plain radiographs.

Mean follow-up and age was 5.2 years and 74 years in both groups. Functional outcomes were significantly higher in OA compared with CTA with OSS improving from 18 to 37.5 and 15 to 26 in both groups respectively. Forward flexion improved from 60° to 126° and 42° to 74° in both groups. Three patients in the CTA group had a deficient subscapularis tendon, two of whom dislocated anteriorly.

Humeral head resurfacing arthroplasty is a viable treatment option for glenohumeral osteoarthritis. In patients with CTA, functional gains are limited. We suggest CSRA should be considered in low demand patients where pain is the primary problem. Caution should be taken in patients with a deficient subscapularis due to the high risk of dislocation.

Purpose

The purpose of this study was to evaluate the short to mid-term results after hemiarthroplasty with extended head prosthesis (CTA head) for patients with cuff tear arthopathy.

Rotator cuff arthropathy is a challenging problem to treat in many patients whose function remains intact despite pain from arthritis. In recent years, the introduction of reverse shoulder arthroplasty has improved the function and pain in pseudoparalytic shoulders with rotator cuff deficiency. However, significant evidence exists to support the use of alternative surgical and non-surgical treatments for those patients who suffer from the pain of arthritis while maintaining an intact force-couple of the rotator cuff and relatively well preserved function.

The treatment of patients with arthritis of the glenohumeral joint with an associated massive irreparable cuff tear is challenging. Since these patients usually have proximal migration of the humerus, the CTA extended head allows a surface with a low coefficient of friction to articulate with the acromion.

Between 2001 and 2006 a total of 48 patients with arthritis of the shoulder joint associated with a massive cuff tear, were treated with a CTA head. The indications for use being Seebauer Type 1a and 1b appearances on x-ray and active abduction of the arm to more than 60° with appropriate analgesia. Preoperatively, a Constant score and an ASES pain and function score were completed as well as standard radiological assessment. These were repeated at follow up. Paired t tests were carried out for all the variables. A Kaplan-Meier survival analysis was performed.

Follow up varied between 2 and 8 years. Improvements in pain, function and all movement parameters were significant at p< 0.001. There was no change in the strength component. Survival analysis showed 94% survival at 8 years (95% CL 8%) there were 2 revisions and 5 deaths. Radiological assessment at follow up revealed no evidence of humeral stem loosening. In 5 (17%) cases however there was evidence of erosion in the surface of the acromion and in 13 (45%) erosion of the glenoid. Finally one component was also seen to have subluxed anteriorly.

This head design has been in use for a number of years. To date there appears to be no reported outcome of their use. This series shows that in an appropriately selected patient a satisfactory clinical outcome can be maintained in the short to medium term. The presence of erosion of the glenoid but also the under surface of the acromion does require continuing monitoring.

Aims. The current evidence comparing the two most common approaches for reverse total shoulder arthroplasty (rTSA), the deltopectoral and anterosuperior approach, is limited. This study aims to compare the rate of loosening, instability, and implant survival between the two approaches for rTSA using data from the Dutch National Arthroplasty Registry with a minimum follow-up of five years. Methods. All patients in the registry who underwent a primary rTSA between January 2014 and December 2016 using an anterosuperior or deltopectoral approach were included, with a minimum follow-up of five years. Cox and logistic regression models were used to assess the association between the approach and the implant survival, instability, and glenoid loosening, independent of confounders. Results. In total, 3,902 rTSAs were included. A deltopectoral approach was used in 54% (2,099/3,902) and an anterosuperior approach in 46% (1,803/3,902). Overall, the mean age in the cohort was 75 years (50 to 96) and the most common indication for rTSA was cuff tear arthropathy (35%; n = 1,375), followed by osteoarthritis (29%; n = 1,126), acute fracture (13%; n = 517), post-traumatic sequelae (10%; n = 398), and an irreparable cuff rupture (5%; n = 199). The two high-volume centres performed the anterosuperior approach more often compared to the medium- and low-volume centres (p < 0.001). Of the 3,902 rTSAs, 187 were revised (5%), resulting in a five-year survival of 95.4% (95% confidence interval 94.7 to 96.0; 3,137 at risk). The most common reason for revision was a periprosthetic joint infection (35%; n = 65), followed by instability (25%; n = 46) and loosening (25%; n = 46). After correcting for relevant confounders, the revision rate for glenoid loosening, instability, and the overall implant survival did not differ significantly between the two approaches (p = 0.494, p = 0.826, and p = 0.101, respectively). Conclusion. The surgical approach used for rTSA did not influence the overall implant survival or the revision rate for instability or glenoid loosening. Cite this article: Bone Joint J 2023;105-B(9):1000–1006

Purpose. Glenoid version has been correlated with tears within the rotator cuff. Cuff tear arthropathy is an evolution of multiple unhealed tendons ultimately resulting in pseudoparalysis. Although several factors are critical to allow tendon healing, we have observed that there is less glenoid version in patients with cuff tear arthropathy. This was compared to those with osteoarthritis where rotator cuff tears are uncommon. We hypothesize that patients undergoing inverse prosthesis generally have a near neutral glenoid. Method. A single surgeons practice (JPW) was retrospectively reviewed for all cuff tear arthropathy and osteoarthritis patients undergoing primary shoulder arthroplasty. (Zimmer, Warsaw, IN). Glenoid version was measured by 2 fellowship trained shoulder surgeons. Inter and intra-class correlation was measured. Results. The axial CT scans of 84 patients (cuff tear arthropathy and osteoarthritis) were evaluated. Inter and intra-class correlation was excellent (0.96, 0.97). Glenoid version was between 4.1 +/− 3.6 and 16.5 +/− 8.6 degrees for cuff tear arthropathy and osteoarthritis, respectively (p < 0.0001). Conclusion. Our observation of near neutral glenoid version in patients with cuff tear arthropathy has not been reported in the literature. The anatomical version of the glenoid may be a risk factor in patients undergoing rotator cuff repair. This may predispose certain individuals to cuff tear arthropathy compared to those with increased retroversion

Aims. The aim of this study was to describe a quantitative 3D CT method to measure rotator cuff muscle volume, atrophy, and balance in healthy controls and in three pathological shoulder cohorts. Methods. In all, 102 CT scans were included in the analysis: 46 healthy, 21 cuff tear arthropathy (CTA), 18 irreparable rotator cuff tear (IRCT), and 17 primary osteoarthritis (OA). The four rotator cuff muscles were manually segmented and their volume, including intramuscular fat, was calculated. The normalized volume (NV) of each muscle was calculated by dividing muscle volume to the patient’s scapular bone volume. Muscle volume and percentage of muscle atrophy were compared between muscles and between cohorts. Results. Rotator cuff muscle volume was significantly decreased in patients with OA, CTA, and IRCT compared to healthy patients (p < 0.0001). Atrophy was comparable for all muscles between CTA, IRCT, and OA patients, except for the supraspinatus, which was significantly more atrophied in CTA and IRCT (p = 0.002). In healthy shoulders, the anterior cuff represented 45% of the entire cuff, while the posterior cuff represented 40%. A similar partition between anterior and posterior cuff was also found in both CTA and IRCT patients. However, in OA patients, the relative volume of the anterior (42%) and posterior cuff (45%) were similar. Conclusion. This study shows that rotator cuff muscle volume is significantly decreased in patients with OA, CTA, or IRCT compared to healthy patients, but that only minimal differences can be observed between the different pathological groups. This suggests that the influence of rotator cuff muscle volume and atrophy (including intramuscular fat) as an independent factor of outcome may be overestimated. Cite this article: Bone Jt Open 2021;2(7):552–561

Introduction: Glenohumeral arthritis with a massive rotator cuff tear is a devastating condition that seriously compromises the comfort and function of the shoulder. Cuff tear arthropathy presents a unique surgical challenge and many arthroplasty options were used for its treatment. The purpose of this study was to evaluate the clinical and radiological results of Copeland cementless surface replacement arthroplasty (CSRA) applied in patients with cuff tear arthropathy and intact subscapularis function. Patients and Methods: The study was conducted on twenty five shoulders in twenty five patients with cuff tear arthropathy with the subscapularis tendon still intact. The patients were prospectively followed up clinically and radiologically for a mean of 26 months (range, 15–38 months). There were 16 female and 9 male shoulders. The mean age was 69.04 years (range,53–83years). The mean operative time was 38 minutes (range, 28–56minutes). The clinical assessment was performed with the Constant score. Results: The constant score significantly improved from a mean of 14.04 points preoperatively to 53.17 points postoperatively. Of the patients, 88% considered the shoulder to be much better or better as a result of the operation. Radiologically, the humeral offset, the lateral gleno-humeral offset (coracoid base to the greater tuberosity), height of center of instant rotation and the acromio-humeral distance were significantly increased. No intra-or postoperative complications encountered. Conclusion: Our early results with the use of Copeland surface replacement in selected cases with cuff tear arthropathy were encouraging. The patients showed significant clinical (pain and range of motion) and radiological improvements. Moreover, if the surface replacement were to fail for any reason, it can be revised to a reverse prosthesis type as there is no lack of bone stock

Aims. This systematic review asked which patterns of complications are associated with the three reverse total shoulder arthroplasty (RTSA) prosthetic designs, as classified by Routman et al, in patients undergoing RTSA for the management of cuff tear arthropathy, massive cuff tear, osteoarthritis, and rheumatoid arthritis. The three implant design philosophies investigated were medial glenoid/medial humerus (MGMH), medial glenoid/lateral humerus (MGLH), and lateral glenoid/medial humerus (LGMH). Methods. A systematic review of the literature was performed via a search of MEDLINE and Embase. Two reviewers extracted data on complication occurrence and patient-reported outcome measures (PROMs). Meta-analysis was conducted on the reported proportion of complications, weighted by sample size, and PROMs were pooled using the reported standardized mean difference (SMD). Quality of methodology was assessed using Wylde’s non-summative four-point system. The study was registered with PROSPERO (CRD42020193041). Results. A total of 42 studies met the inclusion and exclusion criteria. Rates of scapular notching were found to be significantly higher in MGMH implants (52% (95% confidence interval (CI) 40 to 63)) compared with MGLH ((18% (95% CI 6 to 34)) and LGMH (12% (95% CI 3 to 26)). Higher rates of glenoid loosening were seen in MGMH implants (6% (95% CI 3 to 10)) than in MGLH implants (0% (95% CI 0 to 2)). However, strength of evidence for this finding was low. No significant differences were identified in any other complication, and there were no significant differences observed in PROMs between implant philosophies. Conclusion. This systematic review has found significant improvement in PROMS and low complication rates across the implant philosophies studied. Scapular notching was the only complication found definitely to have significantly higher prevalence with the MGMH implant design. Cite this article: Bone Joint J 2021;103-B(5):813–821

Introduction. Reverse shoulder replacement is a surgical option for cuff tear arthropathy. However scapular notching is a concern. Newer designs of glenospheres are available to reduce scapular notching. Eccentric glenosphere with a lowered centre of rotation have been shown to improve range of adduction in vitro. We hypothesize that the eccentric glenosphere improve clinical outcomes and reduce scapular notching. Method. This is an ongoing randomized controlled double blind prospective clinical trial. Patients 70 years or older at North Shore hospital who have a diagnosis of cuff tear arthropathy and require surgery were consented for this study. Patients were allocated a concentric or eccentric 36 mm glenosphere intraoperatively, using a computer generated randomization contained in a sealed envelope. The surgical technique and post operative rehabilitation were standardized. Patients were followed up by a research nurse and postoperative radiographs were also taken at regular intervals. Clinical assessment include a visual analogue pain score, subjective shoulder rating, American Shoulder and Elbow Society Score, and Oxford shoulder score. Complications were checked for and radiographs were assessed for scapular notching. Results. There were 23 patients in the concentric and 24 patients in the eccentric glenosphere group. Average age and duration of follow up were comparable. There was no statistical significant difference but there was a trend towards better functional outcome and better range of motion in the eccentric glenosphere group. There was no scapular notching in the eccentric and three cases of scapular notching in the concentric glenosphere group. Conclusions. Reverse shoulder replacement significantly improve pain, function and range of motion in patients with cuff tear arthropathy. Eccentric glenosphere prevents scapular notching in the SMR reverse prosthesis

Aim of Study: To evaluate the efficacy of pulsed radio-frequency ablation to the suprascapular nerve in patients with chronic shoulder pain secondary to cuff tear arthropathy. Methods: Twelve patients with chronic shoulder pain secondary to cuff tear arthropathy were recruited following ethics approval. Mean age 68 yrs (60–83 yrs). The suprascapular notch was identified under image intensifier and the suprascapular nerve lesioned with pulsed radiofrequency ablation for 120 seconds. Patients were assessed with the Oxford and Constant Shoulder scores, Visual Analogue pain score and sleep score pre, 3 and 6 months post procedure. Statistical analysis was undertaken using the Friedman test (non parametric analysis of variance). Results: Ten patients had an improvement in the visual analogue pain score and Constant score, 11 in the Oxford score and all an improvement in sleep pattern. Conclusions: Shoulder pain was reduced in 10 out 12 patients up to 6 months post procedure. This procedure may be a useful adjunct in elderly patients with painful cuff tear arthropathy who are not suitable for surgery

In recently, reverse shoulder arthroplasty for rotator cuff deficient arthritis is widely used in the world. However, a high complication rate was reported and worried about long-term results after reverse shoulder arthroplasty. From 2001, we performed a novel strategy for these cases such as rotator cuff reconstruction w/ or w/o muscle transfer and a humeral head replacement with using smallest head to decrease joint volume. The aim of this study was to investigate with clinical outcomes after this surgery more than two years follow-up. Materials & methods. Fifty six shoulders underwent humeral head replacement (HHR) with or without tendon transfer for cuff tear arthropathy was able to follow-up more than two years. The mean age was 74 years (60 to 83 years). 42 cuff tear arthropathy, 6 RA, 5 re-tear after cuff repair with arthritis, and 1 arthritis after infection were included. Coracoacromial arch preserved Superior approach with preserving coracoacromial arch was used for replacement the humeral stem and head. Almost of the cases could be repaired with using a smallest head because of the height of humeral head and joint volume were decreased. However, when rotator cuff remained in irreparable condition, a latissimus dorsi tendon or a pectoralis major tendon from same shoulder was transferred for cuff reconstruction. The patients were divided by 2 groups; 36 shoulders of HHR without tendon transfer and 20 shoulders of HHR with tendon transfer. Each patient was evaluated with Japan Orthopaedic Association score (JOA score) and modified Neer's limited goals rating scale after a least 2 year of follow-up. Results. In all cases, preoperative severe pain was dramatically improved. JOA score improve from 40.2 preoperatively to 80.2 postoperatively. Twelve shoulders estimated as excellent in modified Neer's classification, 34 in satisfactory and 10 in unsatisfactory. Half of cases with RA were unsatisfactory results. Postoperative active flexion statistically improved compared to preoperative range of motion. Averaged postoperative flexion was 136 degrees (preop.;68.8) and postoperative external rotation was 28.6 degrees (preop.;13.2). However, there was no significant difference of external rotation in the HHR group between pre and postoperative evaluation. The radiographic evaluation showed four cases of glenoid erosion. One case had arthroscopic Suprascapular nerve release eight years after surgery. Conclusions. The current results were consistent with the prior studies. Our novel strategy is considered as one of useful procedure for cuff tear arthropathy. However, the case which classified with Seebauer type IIB should not be recommended

Abstract. Background. To determine the long-term survival outcomes of Copeland Resurfacing Hemiarthroplasty (CRHA) performed by a single surgeon series. Methods. A retrospective cohort study which looked at patients who underwent CRHA over 6 years. Re-operations including revisions with component exchange taking place in our hospital and at local centres were reviewed. Oxford Shoulder Score (OSS) was used to assess their functional outcomes pre- and post-CRHA. Results. 80 CRHAs were performed in 72 patients between 2007 and 2013 with a mean follow-up of 6.5 years. The mean follow-up was 79 months (50–122). The primary indication for CRHA was osteoarthritis (76.3%), cuff tear arthropathy (16.3%), rheumatoid arthritis (5%) and post-trauma (1.3%). The mean pre-operative OSS was 16, which doubled following CRHA surgery. Fifteen patients underwent revision surgery due to ongoing glenoid pain with a mean revision time following primary CRHA being 49 months. Projected survival at the endpoints 5,7 and 10 years were 83, 81 and 79% respectively. Conclusion. This study provides us with a much longer average follow-up period in comparison to many other studies published. Previous studies, support resurfacing as a useful implant in reducing pain and improving function in the short-term; but this series demonstrates over the medium-term a relatively high revision rate of about 20% in comparison with other arthroplasty options, despite the revision rate seeming to plateau from the 5-year mark onwards

Introduction. Acromial and scapular fractures are a rare but difficult complication with reverse total shoulder arthroplasty (rTSA), with an incidence rate reported from 1–10%. The risk factors associated with these fractures types is largely unknown. The goal of this study is to analyze the clinical outcomes, demographic and comorbidity data, and implant sizing and surgical technique information from 4125 patients who received a primary rTSA with one specific prosthesis (Equinoxe, Exactech, Inc) and were sorted based on the radiographic documentation of an acromial and/or scapula fracture (ASF) to identify factors associated with this complication. Methods. 4125 patients (2652F/1441M/32 unspecified; mean age: 72.5yrs) were treated with primary rTSA by 23 orthopaedic surgeons. Revision and fracture reverse arthroplasty cases were excluded. The radiographic presence of each fracture was documented and classified using the Levy classification method. 61 patients were identified as having ASF, 10 patients had fractures of the Type 1, 32 patients had Type 2, and 18 patients had Type 3 fractures according to Levy's classification. One fracture was not classifiable. Pre-op and post-op outcome scoring, ROM as well as demographic, comorbidity, implant, and surgical technique information were evaluated for these 61 patients and compared to the larger cohort of patients to identify any associations. A two-tailed, unpaired t-test identified differences (p<0.05). Results. The overall rate of ASF was 1.48% with the average time after surgery occurring at 12.9 ± 17.9 months (range 1 day to 78 months). Men had an ASF rate of 0.69% (10 of 1441); whereas women had a rate of 1.92% (51 of 2652). Patients with ASF were observed to be significantly shorter than patients without ASF (65.1 in vs 63.3 in, p=0.0004). ASF were more common in females (p=0.0019), have Rheumatoid Arthritis (p=0.0051), Cuff Tear Arthropathy (p=0.0093), or previous shoulder surgery (p=0.0189). Patient's weight did not correlate, nor did BMI. No difference was observed in humeral stem size, glenosphere diameter, or the humeral tray offset, humeral liner offset, or combined humeral tray+liner offset. The average number of screws used in the fracture group was significantly more than in the non-fracture group (p=0.0327), and 93% of patients in the fracture group had a screw in the superior hole of the baseplate. Pre-operatively, patients who developed ASF had significantly worse ASES (p=0.0104) and SPADI (p=0.0136) scores and also had significantly worse forward elevation (p=0.0237) and internal rotation (p=0.0054) than those who did not develop ASF. At latest follow-up, patients with ASF had significantly worse SST, UCLA, ASES, Constant, and SPADI scores (all p<0.0001); significantly worse abduction, forward elevation, internal rotation, strength (all p<0.0001); and significantly less preop-to-postop improvement in all measured outcomes, except for external rotation (all p<0.0001). Finally, 24% of fractures were identified as being caused by a traumatic event, 28% of patients with fractures had a previous acromioplasty, and 53% of fractures were Levy type 2. Discussion. Acromial and scapular fractures after rTSA are a rare complication, with an incidence of 1.48% in this analysis of 4125 patients with a single rTSA prosthesis. These fractures were observed to occur at an average of 12.9 months after surgery, but were observed as early as 1 day and as late as 6.5 years. Female patients, Rheumatoid Arthritis, Cuff Tear Arthropathy, previous shoulder surgery, relatively worse pre-operative ASES or SPADI scores, relatively decreased pre-operative forward elevation and internal rotation as well as a larger number of screws placed in the baseplate all were significantly associated with the occurrence of ASF. Although 93% of patients with ASF had a screw placed in the superior hole of the baseplate, we cannot conclude that this is a driving factor at this time, as the superior screw number for the non-fracture group was not recorded. Future work should evaluate if usage of a superior glenoid baseplate screw and previous acromioplasty are also risk factors for these fracture types after rTSA. This study is the largest ever performed analysis of this rare complication and provides news insight into the predisposing risk factors to consider when evaluating patients for rTSA

BACKGROUND:. Few studies have evaluated at a medium-term follow-up the use of semiconstrained reverse shoulder arthroplasty (RSA) for primary glenohumeral osteoarthritis, massive rotator cuff tear, or cuff tear arthropathy excluding any other shoulder disease. Moreover, data on patients' quality of life after this surgery are lacking. METHODS:. In this prospective cohort study, 80 patients were evaluated after an RSA for either primary osteoarthritis, massive rotator cuff tear, or cuff tear arthropathy with the Constant-Murley score (CMS), ROM, and Short Form Health Survey (SF-36). A radiologic assessment was performed pre- and postoperatively. RESULTS:. At a mean 5-year follow-up, the cumulative survival rate was 97.3% and significant improvements in the CMS and ROM were observed when compared with the baseline values. The CMS was 93.2% of the sex- and age-matched normal values. The postoperative SF-36 scores showed no significant differences compared with normative data. Younger patients and subjects with worse preoperative conditions achieved the greatest benefit after RSA. A 70% scapular notching rate was noted and the length of follow-up was found to be associated with the severity of scapular notching. CONCLUSIONS:. This study introduces new predictors for surgical outcomes, and it shows that patients who had undergone RSA a mean of 5 years earlier exhibit similar functionality and health-related quality of life with respect to healthy controls

Reverse shoulder arthroplasty (RSA) is commonly used to treat patients with rotator cuff tear arthropathy. Loosening of the glenoid component remains one of the principal modes of failure and is the main complication leading to revision. For optimal RSA implant osseointegration to occur, the micromotion between the baseplate and the bone must not exceed a threshold of 150 µm. Excess micromotion contributes to glenoid loosening. This study assessed the effects of various factors on glenoid baseplate micromotion for primary fixation of RSA. A half-fractional factorial experiment design (2k-1) was used to assess four factors: central element type (central peg or screw), central element cortical engagement according to length (13.5 or 23.5 mm), anterior-posterior (A-P) peripheral screw type (nonlocking or locking), and bone surrogate density (10 or 25 pounds per cubic foot [pcf]). This created eight unique conditions, each repeated five times for 40 total runs. Glenoid baseplates were implanted into high- or low-density Sawbones™ rigid polyurethane (PU) foam blocks and cyclically loaded at 60 degrees for 1000 cycles (500 N compressive force range) using a custom designed loading apparatus. Micromotion at the four peripheral screw positions was recorded using linear variable displacement transducers (LVDTs). Maximum micromotion was quantified as the displacement range at the implant-PU interface, averaged over the last 10 cycles of loading. Baseplates with short central elements that lacked cortical bone engagement generated 373% greater maximum micromotion at all peripheral screw positions compared to those with long central elements (p < 0.001). Central peg fixation generated 360% greater maximum micromotion than central screw fixation (p < 0.001). No significant effects were observed when varying A-P peripheral screw type or bone surrogate density. There were significant interactions between central element length and type (p < 0.001). An interaction existed between central element type and level of cortical engagement. A central screw and a long central element that engaged cortical bone reduced RSA baseplate micromotion. These findings serve to inform surgical decision-making regarding baseplate fixation elements to minimize the risk of glenoid loosening and thus, the need for revision surgery

Introduction and Objective. Only few studies have investigated the outcome of exercises in patients with glenohumeral osteoarthritis (OA) or rotator cuff tear arthropathy (CTA), and furthermore often excluded patients with a severe degree of OA. Several studies including a Cochrane review have suggested the need for trials comparing shoulder arthroplasty to non-surgical treatments. Before initiation of such a trial, the feasibility of progressive shoulder exercises (PSE) in patients, who are eligible for shoulder arthroplasty should be investigated. The aim was to investigate whether 12 weeks of PSE is feasible in patients with OA or CTA eligible for shoulder arthroplasty. Moreover, to report changes in shoulder function and range of motion (ROM) following the exercise program. Materials and Methods. Eighteen patients (11 women, 14 OA), mean age 70 years (range 57–80), performed 12 weeks of PSE with 1 weekly physiotherapist-supervised and 2 weekly home-based sessions. Feasibility was measured by drop-out rate, adverse events, pain and adherence to PSE. Patients completed Western Ontario Osteoarthritis of the Shoulder (WOOS) score and Disabilities of the Arm, Shoulder and Hand (DASH). Results. Two patients dropped out and no adverse events were observed. Sixteen patients (89%) had high adherence to the physiotherapist-supervised sessions. Acceptable pain levels were reported. WOOS improved mean 23 points (95%CI:13;33), and DASH improved mean 13 points (95%CI:6;19). Conclusions. PSE is feasible, safe and may improve shoulder pain, function and ROM in patients with OA or CTA eligible for shoulder arthroplasty. PSE is a feasible treatment that may be compared with arthroplasty in a RCT setting

Background. The use of reverse total shoulder arthroplasty considerably increased since first introduced by Paul Grammont in the late 1980s. Over the past few years, results from several mid- and long-term clinical studies have demonstrated good functional outcomes and pain relief. However, several complications, especially inferior glenoid notching, and high revision rates were reported in the literature. Improvements in prosthesis design should contribute to a lower complication rate and lesser amount of glenoid erosion. Few studies have reported the clinical outcome andcomplications of Anatomical Shoulder Inverse/ Reverse Prosthesis. This study documents 2- and 6-year clinical and radiological results following reversed shoulder arthroplasty using this novel prosthesis. Methods. We report the results for sixty-eight consecutive patients (seventy shoulders) with cuff tear arthropathy (CTA) treated with Anatomical Shoulder Inverse/Reverse Prosthesis between 2006 and 2008. Two groups were defined: (A) primary treatment and (B) revision. Clinical evaluation tools comprised Constant-Murley score (CS), range of motion, and a visual analog scale to assess pain. Radiographs (anteroposterior view in neutral position) were evaluated for notching and radiolucent lines. Any complications were recorded. Results. In total, 66 shoulders (94%) with a mean follow-up of 30.0 months were initially analysed. CS increased from preoperatively 20.2 to postoperatively 53.6 points. Inferior scapular notching was identified in 58% of patients, primarily grade 1 and 2 (low-graded). 16% of patients experienced a complication, including instability, infection or periprosthetic fracture. 58 patients (83%) were re-evaluated 69.0 months after implantation. CS decreased to 50.2 points (n.s.). 16 patients (23%) had postoperative complication at final follow-up. We observed progressive radiographic changes in 75% and an increased frequency of large notches (grade 3 and 4). No significant difference regarding clinical outcome was detected between group A and B after both 2 and 6 years. Conclusion. Total shoulder arthroplasty with the Anatomical Shoulder Inverse/Reverse Prosthesis is a reliable treatment option in patients with cuff tear arthropathy. Primary and revision arthropathies result in similar improvements in range of motion and pain. Constant-Murley score and radiographic changes deteriorated with time. Inferior scapular notching appeared rapidly after implantation. A change of prosthesis design and prosthetic overhang intraoperatively seems to be the most effective way to prevent scapular conflict. The complication rate in our series is equally to previously reported rates

Introduction: The reverse shoulder arthroplasty (RSA) is becoming increasingly common and the indications expanded. The objective of this study is to report the indications and results of RSA in a large multicenter study. Methodology: A retrospective, multicenter study was conducted including all RSA implanted between 1992 and 2002 in five centers in France. Of 457 patients involved in this study, 243 patients (53%) had cuff pathology: 149 had cuff tear arthropathy, 48 had massive cuff tears, and 45 had failed cuff surgery. Ninety-nine (22%) had revision of previous prostheses. Sixty (13%) had fracture-related problems. Twenty-six (6%) had osteoarthritis and two percent each had rheumatoid arthritis, tumors or other conditions. Three hundred and eighty-nine (85%) shoulders were available for review with greater than 2 years follow-up. The average age at review was 75.6 years (range, 22–92). The average follow-up was 43.5 months (range, 24–142). Results: Significant improvement was noted in Constant scores for pain (3.5 to 12.1), activity (5.8 to 15.1), mobility (12.1 to 24.5), and strength (1.3 to 6.1) (p< .0001). Active elevation improved, but active internal and external rotation did not. The results were dependent on the indication. Cuff tear arthropathy had the best results while revision procedures had the worst. Young age, preoperative stiffness, teres minor deficiency, tuberosity non-union and preoperative complaints of pain rather than loss of function tended to be associated with inferior results. The deltopectoral approach tended toward greater active elevation but greater risk of instability. Survivorship to the endpoints of revision and loosening was better for patients with rotator cuff problems than for patients with failed prior hemiarthroplasty. The functional results were noted to deteriorate progressively after six years in the cuff tear group, after five years in the revision hemiarthroplasty group, after three years in the osteoarthritis group, and after one year in the revision total shoulder arthroplasty group. Conclusions: The overall results of RSA are satisfactory and predictable. Functional results improved with improved active elevation, but no improvement in active internal and external rotation. However, results are dependent on the etiology

Purpose: The reverse shoulder arthroplasty (RSA) is becoming increasingly common and the indications expanded. The objective of this study is to report the indications and results of RSA in a large multicenter study. Method: A retrospective, multicenter study was conducted including all RSA implanted between 1992 and 2002 in five centers in France. Of 457 patients involved in this study, 243 patients (53%) had cuff pathology: 149 had cuff tear arthropathy, 48 had massive cuff tears, and 45 had failed cuff surgery. Ninety-nine (22%) had revision of a previous arthroplasty. Sixty (13%) had fracture-related problems. Twenty-six (6%) had osteoarthritis and two percent each had rheumatoid arthritis, tumors or other conditions. Three hundred and eighty-nine (85%) shoulders were available for review at a mean follow-up of 44 months (range, 24–142). The average age at review was 76 years (range, 22–92). Results: Overall, significant improvement was noted in Constant scores for pain (3.5 to 12.1), activity (5.8 to 15.1), mobility (12.1 to 24.5) and strength (1.3 to 6.1) (p< 0.0001). Active elevation improved (p< 0.0001), but active internal and external rotation did not. The results were dependent on the indication. Cuff tear arthropathy had the best results while revision procedures had the worst. Young age, preoperative stiffness, teres minor deficiency, tuberosity non-union and preoperative complaints of pain rather than loss of function tended to be associated with inferior results. The deltopectoral approach tended toward greater active elevation but greater risk of instability. Survivorship to the endpoints of revision and loosening was better for patients with cuff tear pathology than for patients with failed prior hemiarthroplasty. The functional results were noted to deteriorate progressively after six years in the cuff tear pathology group, after five years in the revision hemiarthroplasty group, after three years in the osteoarthritis group, and after one year in the revision total shoulder arthroplasty group. Conclusion: Overall results of RSA are satisfactory and predictable. Functional results improved with improved active elevation, but no improvement in active internal and external rotation. However, results are dependent on etiology

Radiological changes and differences between cemented and uncemented components of Grammont reverse shoulder arthroplasties (DePuy) were analysed at a mean follow-up of 9.6 years (8 to 12). Of 122 reverse shoulder arthroplasties implanted in five shoulder centres between 1993 and 2000, a total of 68 (65 patients) were available for study. The indications for reversed shoulder arthroplasty were cuff tear arthropathy in 48 shoulders, revision of shoulder prostheses of various types in 11 and massive cuff tear in nine. The development of scapular notching, bony scapular spur formation, heterotopic ossification, glenoid and humeral radiolucencies, stem subsidence, radiological signs of stress shielding and resorption of the tuberosities were assessed on standardised true anteroposterior and axillary radiographs. A scapular notch was observed in 60 shoulders (88%) and was associated with the superolateral approach (p = 0.009). Glenoid radiolucency was present in 11 (16%), bony scapular spur and/or ossifications in 51 (75%), and subsidence of the stem and humeral radiolucency in more than three zones were present in three (8.8%) and in four (11.8%) of 34 cemented components, respectively, and in one (2.9%) and two (5.9%) of 34 uncemented components, respectively. Radiological signs of stress shielding were significantly more frequent with uncemented components (p < 0.001), as was resorption of the greater (p < 0.001) and lesser tuberosities (p = 0.009)

Surgeries for reverse total shoulder arthroplasty (RTSA) significantly increased in the last ten years. Initially developed to treat patients with cuff tear arthropathy (CTA) and pseudoparalysis, wider indications for RTSA were described, especially complex proximal humerus fractures. We previously demonstrated in patients with CTA a different sequence of muscular activation than in normal shoulder, with a decrease in deltoid activation, a significant increase of upper trapezius activation and slight utility of the latissimus dorsi. There is no biomechanical study describing the muscular activity in patients with RTSA for fractures. The aim of this work is to describe the in vivo action of RTSA in patients with complex fractures of the proximal humerus. We conducted an observational prospective cohort study comparing 9 patients with RTSA for complex humerus fracture (surgery more than 6 months, healed tuberosities and rehabilitation process achieved) and 10 controls with normal shoulder function. Assessment consisted in a synchronized analysis of range of motion (ROM) and muscular activity on electromyography (EMG) with the use of 7 bipolar cutaneous electrodes, 38 reflective markers and 8 motion-recording cameras. Electromyographic results were standardized and presented in muscular activity (RMS) adjusted with maximal isometric contractions according to the direction tested. Five basic movements were evaluated (flexion, abduction, neutral external rotation, external rotation in 90° of abduction and internal rotation in 90° of abduction). Student t-test were used for comparative descriptive analysis (p < 0,05). The overall range of motion with RTSA is very good, but lower than the control group: flexion 155.6 ± 10 vs 172.2 ± 13.9, p<0.05, external rotation at 90° 55.6 ± 25 vs 85.6 ± 8.8, p<0,05, internal rotation at 90° 37.8 ± 15.6 vs 52.2 ± 12, p<0,05. The three heads of the deltoid are more stressed during flexion and abduction in the RTSA group (p. The increased use of the 3 deltoid chiefs does not support the hypothesis proposed by Grammont when the RTSA is performed for a complex proximal humerus fracture. This can be explained by the reduced dispalcement of the rotation center of the shoulder in these patients compared to those with CTA. These patients also didn't present shoulder stiffness before the fracture. The maximal muscle activity of the trapezius in flexion and of the latissimus dorsi in flexion and abduction had not been described to date. These new findings will help develop better targeted rehabilitation programs. In addition, the significant role of the latissimus dorsi must question the risks of its transfer (L'Episcopo procedure) to compensate for external rotation deficits

Superiorly eroded glenoids in cuff tear arthropathy represent a surgical challenge for reconstruction. The bone loss orientation and severity may influence glenoid component fixation. This computed-tomography study quantifies both the degree of erosion and orientation in superiorly eroded Favard E2 glenoids. We hypothesized that the erosion in E2 glenoids does not occur purely superiorly, rather, it is oriented in a predictable posterosuperior orientation with a largely semicircular line of erosion. Three-dimensional reconstructions of 40 shoulders with E2 glenoids (28 female, 12 male patients) at a mean age of 74 years (range, 56–88 years) were created from computed-tomography images. Point coordinates were extracted from each construct to analyze the morphologic structure. The anatomical location of the supra- and infraglenoid tubercle guided the creation of a superoinferior axis, against which the orientation angle of the erosion was measured. The direction and, thus, orientation of erosion was calculated as a vector. By placing ten point coordinates along the line of erosion and creating a circle of best fit, the radius of the circle was placed orthogonally against a chord that resulted by connecting the two outermost points along the line of erosion. To quantify the extent of curvature of the line of erosion between the paleo- and neoglenoid, the length of the radius of the circle of best fit was calculated. Individual values were compared against the mean of circle radii. The area of bony erosion (neoglenoid), was calculated as a percentage of the total glenoid area (neoglenoid + paleoglenoid). The severity of the erosion was categorized as mild (0% to 33%), moderate (34% to 66%), and severe erosion (>66%). The mean orientation angle between the vector of bony erosion and the superoinferior axis of the glenoid was 47° ± 17° (range, 14° – 74°) located in the posterosuperior quadrant of the glenoid, resulting in the average erosion being directed between the 10 and 11 o'clock position (right shoulder). In 63% of E2 cases, the line of erosion separating the paleo- and neoglenoids was more curved than the average of all bony erosions in the cohort. The mean surface area of the neoglenoid was 636 ± 247 mm2(range, 233 – 1,333 mm2) and of the paleoglenoid 311 ± 165 mm2(range, 123 – 820 mm2), revealing that, on average, the neoglenoids consume 67% of the total glenoid surface. The extent of erosion of the total cohort was subdivided into one mild (2%), 14 moderate (35%) and 25 severe (62%) cases. Using a clock-face for orientation, the average orientation of type E2 glenoid defects was directed between the 10 and 11 o'clock position in a right shoulder, corresponding to the posterosuperior glenoid quadrant. Surgeons managing patients with E2 type glenoids should be aware that a superiorly described glenoid erosion is oriented in the posterosuperior quadrant on the glenoid clock-face when viewed intra-operatively. Additionally, the line of erosion in 63% of E2 glenoids is substantially curved, having a significant effect on bone removal techniques when using commercially available augments for defect reconstruction

The age spectrum for patients undergoing shoulder arthroplasty is broadening. Many younger patients now demonstrate shoulder pathology precluding non-arthroplasty reconstruction. The senior population is living longer and “younger”. Therefore, the demands of this patient population to participate in an active lifestyle are growing. Patients with osteoarthritis, cuff tear arthropathy, post-traumatic arthropathy, avascular necrosis, and even forms of inflammatory arthropathy present seeking not only return to simple activities of daily living but the ability to participate in aerobic recreational activities and even work activities which can stretch the limits of shoulder arthroplasty in the physiologic environment of the shoulder. This presentation will provide an overview of patient demands, concerns and activity level following shoulder arthroplasty. We will provide a prospective of allowable, recommended and discouraged activities depending on the underlying source of pathology in the type of arthroplasty implants employed. An overview of our four phases of rehabilitation protocol will be presented focusing on phase four, “work in sports hardening”

INTRODUCTION. Reverse shoulder arthroplasty (RSA) provides an effective alternative to anatomic shoulder replacements for individuals with cuff tear arthropathy, but certain osteoarthritic glenoid deformities make it challenging to achieve sufficient long term fixation. To compensate for bone loss, increase available bone stock, and lateralize the glenohumeral joint center of rotation, bony increased offset RSA (BIO-RSA) uses a cancellous autograft for baseplate augmentation that is harvested prior to humeral head resection. The motivations for this computational study are twofold: finite element (FE) studies of BIO-RSA are absent from the literature, and guidance in the literature on screw orientations that achieve optimal fixation varies. This study computationally evaluates how screw configuration affects BIO-RSA graft micromotion relative to the implant baseplate and glenoid. METHODS. A senior shoulder specialist (GSA) selected a scapula with a Walch Type B2 deformity from patient CT scans. DICOM images were converted to a 3D model, which underwent simulated BIO-RSA with three screw configurations: 2 divergent superior & inferior locking screws with 2 convergent anterior & posterior compression screws (SILS); 2 convergent anterior & posterior locking screws and 2 superior & inferior compression screws parallel to the baseplate central peg (APLS); and 2 divergent superior & inferior locking screws and 2 divergent anterior & posterior compression screws (AD). The scapula was assigned heterogeneous bone material properties based on the DICOM images’ Hounsfield unit (HU) values, and other components were assigned homogenous properties. Models were then imported into an FE program for analysis. Anterior-posterior and superior-inferior point loads and a lateral-medial distributed load simulated physiologic loading. Micromotion data between the RSA baseplate and bone graft as well as between the bone graft and glenoid were sub-divided into four quadrants. RESULTS. In all but 1 quadrant, APLS performed the worst with the graft having an average micromotion of 347.1µm & 355.9 µm relative to the glenoid and baseplate, respectively. The SILS configuration ranked second, having 211.2 µm & 274.4 µm relative to the glenoid and baseplate. AD performed best, allowing 247.4 µm & 225.4 µm of graft micromotion relative to the glenoid and baseplate. DISCUSSION. Both APLS and SILS techniques are described in the literature for BIO-RSA fixation; however, the data indicate that AD is superior in its ability to reduce graft micromotion, and thus some revision to common practices may be necessary. While these micromotion data are larger than data in the extant RSA literature, there are several factors that account for this. First, to properly model the difference between locking and compression screws, we simulated friction between the compression screw heads and baseplate rather than a tied constraint as done in other studies, resulting in larger micromotion. Second, the trabecular bone graft is at greater risk of deforming than metallic spacers used when studying micromotion with glenosphere lateralization, increasing graft deflection magnitude. Future work will investigate the effects of various BIO-RSA variables. For any figures or tables, please contact authors directly

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

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

We undertook 37 reverse total shoulder replacements within a 2 yr period for chronic complex shoulder conditions. All cases were undertook by one of two upper limb consultant orthopaedic surgeons. At time of listing for operation, the decision as to whether to undertake a bony-increased offset reverse total shoulder was made. Retrospective data was collected on the need for analgesia at final follow up and range of movement. Of the 37 patients, 12 underwent BIO-RSA procedures. Indications for surgery was predominantly rotator cuff arthropathy (n=9) but two patients had severe OA and one had a complex proximal humeral fracture. The average age of the patient was 76.6 yrs (69–87 yrs) with a mean follow-up of 6.8 months (6 weeks to 1 yr). The remaining 25 patients were similar in terms of indication, with 18 patients with cuff tear arthropathies and 7 with severe OA. Average age was slightly lower at 74.9 years (50–85). In terms of range of movement, outcomes between the two groups were broadly similar; those receiving BIO-RSA having an active forward flexion of 90.5° (50–130°) and abduction 88.6° (40–160°). Both groups had excellent analgesic effect with 92% in each either being completely painfree (33.3% BIO-RSA and 44% RSA) or requiring only occasional analgesia. The vast majority of patients were either very satisfied or satisfied with the outcome of the surgery, with one patient in the BIO-RSA group being slightly dissatisfied and three in RSA group. If grafting is necessary, the use of BIO-RSA within this centre seems to have comparable results to those undergoing standard RSA

Reverse Total shoulder arthroplasty (RTSA) has become an increasingly used solution to treat osteoarthritis and cuff tear arthropathy. Though successful there are still 10 to 65% complication rates reported for RTSA. Complication rates range over different reverse shoulder designs but a clear understanding of implant design parameters that cause complications is still lacking within the literature. In efforts to reduce complication rates (Implant fixation, range of motion, joint stiffness, and fracture) and improve clinical/functional outcomes having to do with proper muscle performance we have employed a computational approach to assess the sensitivity of muscle performance to changes in RTSA implant geometry and surgical placement. The goal of this study was to assess how changes in RTSA joint configuration affect deltoid performance. An approach was developed from previous work to predict a patient's muscle performance. This approach was automated to assess changes in muscle performance over 1521 joint configurations for an RTSA subject. Patient-specific muscle moment arms, muscle lengths, muscle velocities, and muscle parameters served as inputs into the muscle prediction scheme. We systematically varied joint center locations over 1521 different perturbations from the in vivo measured surgical placement to determine muscle normalized operating region for the anterior, lateral and posterior aspects of the deltoid muscle. The joint center was varied according to previous published work from the RTSA subject's nominal surgical position ±4 mm in the anterior/posterior direction, ±12mm in the medial/lateral direction, and −10 mm to 14 mm in the superior/inferior direction (Walker 2015 et al. Table 2). Overall muscle normalized operating length varied over 1521 different implant configurations for the RTSA subject. Ideal muscle normalized operating length variations were found to be in all the fundamental directions that the joint was varied. The anterior deltoid normalized operating length was found to be most sensitive with joint configurations changes in the anterior/posterior medial/lateral direction. It lateral deltoid normalized operating length was found to be most sensitive with joint configurations changes in the medial/lateral direction. It posterior deltoid normalized operating length was found to be most sensitive with joint configurations changes in the medial/lateral direction. Reserve actuation for all samples remained below 1 Nm. The most optimal deltoid normalized operating length was implemented by changing the joint configuration in the superior/inferior and medial/lateral directions. Current shoulder models focus on predicting muscle moment arms. Although valuable it does not allow me for active understanding of how lengthening the muscle will affect its ability to generate force. Our study provides an understanding of how muscle lengthening will affect the force generating capacity of each of the heads of the deltoid. With this information improvements can be made to the surgical placement and design of RTSA to improve functional/clinical outcomes while minimizing complications. For any figures or tables, please contact the authors directly

Reverse total shoulder arthroplasty (RTSA) is a well established treatment that provides reproducible results in the treatment of shoulder arthritis and rotator cuff deficiency in the older patient population. However, the results of arthroplasty in younger, more active patients are currently unclear and not as predictable. The purpose of this study is to evaluate the mid-term results of RTSA for patients aged younger than 60 years. A retrospective review of twenty-six patients (twenty six RTSAs) with a mean age of 58.3 years was performed. Minimum follow-up of 5 years was available at a mean follow-up of 73.3 months postoperatively (range, 60–84 months). The preoperative conditions compelling RTSA were as follows: failed rotator cuff repair (17), fracture sequelae (5), failed arthroplasty (1), and cuff tear arthropathy (CTA) (3). We assessed range-of-motion and strength, visual analog scale, American Shoulder and Elbow Surgeons (ASES), and Constant scores. Radiographs were also evaluated for component loosening and scapular notching. All patients were analyzed radiologically and clinically using patient-reported outcome measures. Active forward elevation improved from 56° to 134° and average active external rotation improved from 10.0° to 19.6°. Scores measured with a visual analog pain scale, the Constant score, and the American Shoulder and Elbow Surgeons (ASES) scale all improved significantly. The Visual analog scale (VAS) score for pain improved from 7.5 to 3.0 and the ASES score improved from 31.4 to 72.4, respectively. The normalized postoperative mean Constant score was 88.03. No radiograph showed loosening of the implant at follow-up. Complications included one traumatic subscapularis rupture at six weeks, and one case of periprosthetic fracture. The remaining twenty-four patients were satisfied with the outcome at the time of the latest follow-up and had returned to their desired activity. RTSA in younger patients provided significant subjective improvement in self-assessed shoulder comfort and substantial gain in overall function. Implant loosening and glenoid wear did not appear to be concerns in the mid-term despite the high activity levels of younger patients. Longer-term studies are required to determine whether similar results are maintained over time

Introduction. This paper describes the kinetic and electromyographic contribution of principal muscles around the shoulder of a cohort of patients with reverse total shoulder arthroplasty (RTSA). Surgeries for RTSA significantly increased in the last five years. Initially developed to treat patients with cuff tear arthropathy and pseudoparalysis, wider indications for RTSA were described (massive non repairable rotator cuff tears, complex 4-parts fractures). Since Grammont's theory in 1985, the precise biomechanics of the RTSA has not yet been demonstrated in vivo. Clinical results of patients with RSTA are still unpredictable and vary one from another. Methods. We conducted an observational prospective cohort study comparing 9 patients with RTSA (surgery more than 6 months and rehabilitation process achieved) and 8 controls with normal shoulder function adjusted for age, sex and dominance. Assessment consisted in a synchronized analysis of range of motion (ROM) and muscular activity on electromyography (EMG) with the use of 7 bipolar cutaneous electrodes, 38 reflective markers and 8 motion-recording cameras. Electromyographic results were standardized and presented in muscular activity (RMS) adjusted with maximal isometric contractions according to the direction tested. Five basic movements were evaluated (flexion, abduction, neutral external rotation, external rotation in 90° of abduction and internal rotation in 90° of abduction). Student t-test were used for comparative descriptive analysis (p<0,05). Results. ROM is limited in the RSTA group (flexion 128,5 vs 152,6, p=0,04; abduction 150 vs 166, p=0,02; neutral ext rot 28.3 vs 75.6, p<0,01; 90° ext rot 26,43 vs 70,63, p<0,01, int rot 27.5 vs 49.4, p=0,01). Anterior and middle deltoid shows less muscular activation in RTSA than in controls, sustaining the deltoid potentiation described by Grammont. Posterior deltoid shows decreased activity in external rotation movements in RTSA. Upper trapezius is the main activator in all directions with an early and constant activity in RTSA (p<0,01). Latissimus dorsi demonstrates increased muscular activity in internal rotation with RTSA (p<0,01). Discussion. The sequence of muscular activation in RTSA is different than in normal shoulder. Grammont's theory is confirmed with this study. The significant contribution of both the trapezius and latissimus dorsi has never been described until today. New rehabilitation protocols targeted on those muscle groups could demonstrate better and more homogenous clinical results

Despite reverse total shoulder arthroplasty (RTSA) being primarily indicated for massive rotator cuff tears, it is often possible to repair portions of the infraspinatus and subscapularis of patients undergoing this procedure. However, there is disagreement regarding whether these tissues should be repaired, as their effects remain unclear. Therefore, we investigated the effects of rotator cuff repair and changes in humeral and glenosphere lateralisation (HLat & GLat) on deltoid and joint loading. Six shoulders were tested on an in-vitro muscle driven active motion simulator. Cuff tear arthropathy was simulated in each specimen, which was then implanted with a custom adjustable RTSA fitted with a six axis load sensor. We assessed the effects of 4 RTSA configurations (i.e. all combinations of 0&10mm of HLat & GLat) on deltoid force, joint load, and joint load angle during abduction with/out rotator cuff repair. Deltoid and joint loads recorded by the load cell are reported as a % of Body Weight (%BW). Repeated measures ANOVAs and pairwise comparisons were performed with p<0.05 indicating significance. Cuff repair interacted with HLat & GLat (p=0.005, Fig. 1) such that with no HLat, GLat increased deltoid force without cuff repair (8.1±2.1%BW, p=0.012) and this effect was significantly increased with cuff repair (12.8±3.2%BW, p=0.010). However, adding HLat mitigated this such that differences were not significant. HLat and GLat affected deltoid force regardless of cuff status (−2.5±0.7%BW, p=0.016 & +7.7±2.3%BW, p=0.016, respectively). Rotator cuff repair did significantly increase joint load (+11.9±2.1%BW, p=0.002), as did GLat (+13.3±1.5%BW, p<0.001). The increases in deltoid and joint load caused by rotator cuff repair confirm that it acts as an adductor following RTSA and increases deltoid work. Additionally, cuff repair's negative effects are exacerbated by GLat, which strengthens its adduction affect, while Hlat increases the deltoid's abduction effect thus mitigating the cuff's antagonistic effects. Cuff repair increases concavity compression within the joint; however, Hlat produces a similar effect by wrapping the deltoid around the greater tuberosity – which redirects its force – and does so without increasing the magnitude of muscle and joint loading. The long-term effects of increased joint loading due to rotator cuff repair are unknown, however, it can be postulated that it may increase implant wear, and the risk of deltoid fatigue. Therefore, RTSA implant designs which improve joint compression without increasing muscle and joint loading may be preferable to rotator cuff repair

Shoulder arthroplasty, both primary (TSA) and reverse (RTSA), are common interventions for arthritis and cuff tear arthropathy. The effect of shoulder arthroplasty on shoulder motion is of particular interest in assessing the effectiveness of the procedure and the development and biomechanical testing of implants. A comparison of the arthroplasty shoulder to that of the non-operated contralateral shoulder provides insight into how well the reconstruction has restored natural shoulder motion. The purpose of this study was to ascertain the shoulder motion of patients who have undergone shoulder arthroplasty and to compare the motion of the reconstructed and contralateral natural sides. Eleven human subjects (70±9yrs) who had undergone total shoulder arthroplasty wore a custom instrumented shirt for the waking hours of one day. The 3D orientation of each humeral sensor was transformed with respect to the torso to allow for the calculation of humeral elevation and plane of elevation angles. Joint angles for each subject were then discretised, and the operative and contralateral normal (control) shoulders were then compared. The majority of both the arthroplasty and control shoulder elevation motions took place below 80° of elevation, totaling on average 1910±373 and 1887±312 motions per hour, respectively. Conversely, elevations greater than 80° were significantly less with occurrences totaling only 55±31 and 78±41 motions per hour for the arthroplasty and control shoulders, respectively (p<0.01). Both the arthroplasty and control shoulder were at elevations below 80° for 88±7% and 87±7% of the day, respectively. When the total motion of the arthroplasty and non-operative control shoulders were compared, no statistically significant difference was detected (p=0.8), although the non-operated side exhibited marginally more motion than the operated side, an effect which was larger at higher elevation angles (p=0.3). This study provides insight into the effects of shoulder arthroplasty on thoraco-humeral motion and compares it to the non-operative side. Interestingly, there were no significant differences measured between the arthroplasty and the control side, which may demonstrate the effectiveness of reconstruction on restoring natural shoulder motion. It is interesting to note that on average, each shoulder arthroplasty elevated above 80° approximately 55 times per hour, corresponding to just under 330,000 motions per year. Similarly, when elevations greater than 60° are extrapolated, the resulting yearly motions total approximately 1.5 million cycles (Mc), which suggests that the ‘duty cycle’ of the shoulder is similar to the hip, approximated to be between 1–2 Mc per year. Arthroplasty wear simulators should be calibrated to simulate these patterns of motion, and component design may be improved by understanding the kinematics of actual shoulder motion

Introduction. Humeral head subluxation in patients with cuff tear arthropathy (CTA) and in patients with primary arthrosis has been classified by Hamada and by Walch (type B). These classifications are based on 2D evaluation techniques (AP X-ray view, axial CT images). To our knowledge no 3D evaluation of the direction of humeral head subluxation has been described. Aim. To describe a reproducible 3D measuring technique to evaluate the direction of the humeral head subluxation in shoulder arthropathy. Methods. 72 shoulders with arthrosis type B, 51 nonoperated CTA patients and 151 normal shoulders were 3D reconstructed using Mimics®. The center of rotation on the glenoid was determined using 3-matic® 6.1 with a published technique. Next best fitting sphere of the humeral head and its center was determined. Finally the direction of migration was quantified. The reproducibility of this technique was evaluated using inter- and intra-observer reliability. Results. This technique showed a good inter and intra-observer reliability (p = 0.9). In patients with CTA the humeral head is subluxed in the superoposterior direction (p=0.006) (94°:X-axis; 94° Y-axis versus 92°:X-axis; 92° Y-axis) regardless the type of rotator cuff tear (anterosuperior or superoposterior). In patients with arthrosis type B, the humeral head is subluxed posteriorly (p=0.005) (112°: X-axis; 92° Y-axis versus 92°: X-axis; 92° Y-axis) regardless the type (B1 or B2). Conclusion. With the use of this new developed reproducible measuring technique, the direction of humeral head migration can be evaluated in 3D. In CTA the direction of the migration is superoposterior and in arthrosis type B posteriorly regardless sub-classifications

Reverse total shoulder arthroplasty (RTSA) provides a surgical alternative to conventional shoulder arthroplasty in the rotator cuff deficient shoulder. Short term data has shown consistent improvements in pain and function but higher complication and failure rates have also been reported. The aims of this study were to identify the early and late complications of RTSA, to establish the frequency of glenoid notching, and to assess the post-operative functional outcomes. 21 patients (22 joints) treated with RTSA at Glasgow Royal Infirmary (GRI) between April 2006 and October 2010 were retrospectively reviewed. Indications for surgery included cuff tear arthropathy, revision hemiarthroplasty and fracture malunion. Complication rates were obtained by analysis of follow up data from Bluespier and case notes. Glenoid notching was graded from x-rays by multiple observers using the Sirveaux classification. Outcome was assessed using the Oxford Shoulder Score (OSS) and range of motion (ROM). The complication rate associated with RTSA was 14.3%, effecting 3 patients. One dislocation and 1 ulnar nerve palsy occurred within 30 days post-op. A late complication was represented by 1 dislocation, which required revision. Glenoid notching occurred in 71.4% (15 of 21patients), though the majority had a low Sirveaux classification (grade 1 or 2). OSS increased post-operatively and showed a linear improvement with time (R. 2. = 0.81) and ROM increased significantly post-op compared with pre-op (p<0.001). The complication rate associated with RTSA at GRI was lower than that reported in literature and the outcome was good as defined by ROM and OSS. The rate of glenoid notching was higher than literature reports but the significance of this is unclear as notching may not be associated with loosening

Reverse Total shoulder arthroplasty (RTSA) has become an increasingly used solution to treat osteoarthritis and cuff tear arthropathy. Though successful there are still 10 to 65% complication rates reported for RTSA. Complication rates range over different reverse shoulder designs but a clear understanding of implant design parameters that cause complications is still lacking within the literature. In efforts to reduce complication rates (Implant fixation, range of motion, joint stiffness, and fracture) and improve clinical/functional outcomes having to do with proper muscle performance we have employed a computational approach to assess the sensitivity of muscle performance to changes in RTSA implant geometry and surgical placement. The goal of this study was to assess how changes in RTSA joint configuration affect deltoid performance. An approach was developed from previous work to predict a patient's muscle performance. This approach was automated to assess changes in muscle performance over 1521 joint configurations for an RTSA subject. Patient-specific muscle moment arms, muscle lengths, muscle velocities, and muscle parameters served as inputs into the muscle prediction scheme. We systematically varied joint center locations over 1521 different perturbations from the in vivo measured surgical placement to determine muscle activation and normalized operating region for the anterior, lateral and posterior aspects of the deltoid muscle. The joint center was varied from the RTSA subject's nominal surgical position ±4 mm in the anterior/posterior direction, ±12mm in the medial/lateral direction, and −10 mm to 14 mm in the superior/inferior direction. Overall muscle activity varied over 1521 different implant configurations for the RTSA subject. For initial elevation the RTSA subject showed at least 25% deltoid activation sensitivity in each of the directions of joint configuration change(Figure 1). Posterior deltoid showed a maximal activation variation of 84% in the superior/inferior direction(Figure 1c). Deltoid activation variations lie primarily in the superior/inferior and anterior/posterior directions. An increasing trend was seen for the anterior, lateral and posterior deltoid outside of the discontinuity seen at 28°(Figure 1). Activation variations were compared to subject's experimental data. Reserve actuation for all samples remained below 4Nm(Figure 2). The most optimal deltoid normalized operating length was implemented by changing the joint configuration in the superior/inferior and medial/lateral directions(Figure 3). Current shoulder models utilize cadaver information in their assessment of generic muscle strength. In adding to this literature we performed a sensitivity study to assess the effects of RTSA joint configurations on deltoid muscle performance in a single patient-specific model. For this patient we were able to assess the best joint configuration to improve the patients muscle function and ideally their clinical outcome. With this information improvements can be made to the surgical placement and design of RTSA on a patient-specific basis to improve functional/clinical outcomes while minimizing complications. For any figures or tables, please contact authors directly (see Info & Metrics tab above).