Comparable low revision rates of stemmed and stemless total anatomic shoulder arthroplasties after exclusion of metal backed glenoid components: a collaboration between the Australian and Danish national shoulder arthroplasty registries.

BACKGROUND: The stemmed anatomical total shoulder arthroplasty is the gold standard in the treatment of glenohumeral osteoarthritis. However, the use of stemless total shoulder arthroplasties has increased in recent years. The number of revision procedures are relatively low and therefore it has been recommended that national joint replacement registries should collaborate when comparing revision rates. Therefore, we aimed to compare the revision rates of stemmed and stemless TSA used for the diagnosis of glenohumeral osteoarthritis using data from both the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the Danish Shoulder Arthroplasty Registry (DSR). METHODS: We included all patients who were registered in the AOANJRR and the DSR from January 1 2012 to December 2021 with an anatomical total shoulder arthroplasty used for osteoarthritis. Revision for any reason was used as the primary outcome. We used the Kaplan-Meier method to illustrate the cumulative revision rates and a multivariate cox regression model to calculate the hazard ratios. All analyses were performed separately for data from AOANJRR and DSR, and the results were then reported using a qualitative approach. RESULTS: 13066 arthroplasties from AOANJRR and 2882 arthroplasties from DSR were included. The hazard ratio for revision of stemmed TSA with stemless TSA as reference, adjusted for age and gender, was 1.67 (95% CI 1.34-2.09, p<0.001) in AOANJRR and 0.57 (95% CI 0.36-0.89, p=0.014) in DSR. When including glenoid type and fixation, surface bearing (only in AOANJRR) and hospital volume in the cox regression model the hazard ratio for revision of stemmed TSA compared to stemless TSA was 1.22 (95% CI 0.85-1.75, p=0.286) in AOANJRR and 1.50 (95% CI 0.91-2.45, p=0.109) in DSR. The adjusted hazard ratio for revision of total shoulder arthroplasties with metal backed glenoid components compared to all-polyethylene glenoid components was 2.54 (95% CI 1.70-3.79, p < 0.001) in AOANJRR and 4.1 (95% CI 1.92-8.58, p<0.001) in DSR. CONCLUSION: Based on data from two national shoulder arthroplasty registries, we found no significant difference in risk of revision between stemmed and stemless total shoulder arthroplasties after adjusting for the type of glenoid component. We advocate that metal-backed glenoid components should be used with caution and not on a routine basis.

Stemmed hemiarthroplasty with a suture collar and a common platform system for acute proximal humeral fractures.

Background: Hemiarthroplasty for acute proximal humeral fractures gives disappointing results, often due to rotator cuff insufficiency. Better tuberosity fixation might improve results. Therefore, the aim of this study was to: 1) report the outcome of a stemmed hemiarthroplasty with a common platform system and a modular suture collar; 2) compare the outcome with that of a standard stemmed hemiarthroplasty; 3) report the feasibility of revision arthroplasty with retention of the stem; and 4) to evaluate the association between tuberosity healing and functional outcome. Methods: Forty-four fractures that were deemed not suitable for nonsurgical treatment or open reduction and internal fixation were treated with the Global Unite fracture system between January 2017 and July 2019. The functional and radiographic results at 2 years were compared with the results of 44 Global Fx arthroplasties. The results of patients who had adequate healing of the greater tuberosity were compared with the results of patients who had severe malunion or nonunion (resorption). Results: Mean Oxford Shoulder Score, Constant-Murley Score, and Western Ontario Osteoarthritis of the Shoulder index was 33 (range: 10 to 48), 40 (range: 10 to 98), and 68 (range: 18 to 98) at 2 years. There were no differences in functional outcome scores or in the risk of inadequate healing of the greater tuberosity between the Global Unite and the Global Fx systems. Five (11%) patients underwent revision surgery with retention of the stem. Inadequate tuberosity healing was associated with an inferior Constant-Murley Score (mean difference: 6; 95% confidence interval: 1 to 10, P = .01) and an inferior Oxford Shoulder Score (mean difference: 9; 95% confidence interval: 1 to 16, P = .03). Conclusion: The use of stemmed hemiarthroplasty with a suture collar did not improve the healing of the greater tuberosity or the functional outcome. Five arthroplasties were revised with retention of the stem. This possibility could be arguments for using the Global Unite system when a stemmed hemiarthroplasty is used for acute proximal humeral fractures.

Anterior interosseous nerve syndrome after shoulder arthroscopy.

A 47-year-old woman developed anterior interosseus nerve (AIN) syndrome after subacromial decompression and acromioclavicular joint resection. The operation was performed in the beach chair position and under general anaesthesia without the application of an interscalene block. Two weeks later, the patient presented with paresis of the distal interphalangeal joint of the second finger. Previous studies have proposed traction-type neuropraxia and extravasation of irrigation fluid as leading causes. Exploration and release of the AIN can be indicated if there is no improvement 3-6 months after the operation.

Previous rotator cuff repair increases the risk of revision surgery for periprosthetic joint infection after reverse shoulder arthroplasty.

BACKGROUND: Previous studies have indicated an increased risk of periprosthetic joint infection (PJI) in patients treated with reverse shoulder arthroplasty (RSA) compared with patients treated with anatomic total shoulder arthroplasty. The reason for this is unclear but may be related to a high prevalence of previous rotator cuff repair in patients who are treated with RSA. The purpose of this study was to determine previous non-arthroplasty surgery as a risk factor for revision owing to PJI after RSA for cuff tear arthropathy, massive irreparable rotator cuff tears, or osteoarthritis. METHODS: Data were retrieved from the Danish Shoulder Arthroplasty Registry and medical records. We included 2217 patients who underwent RSA for cuff tear arthropathy, massive irreparable rotator cuff tears, or osteoarthritis between 2006 and 2019. PJI was defined as ≥3 of 5 tissue samples positive for the same bacteria or as definite or probable PJI evaluated based on criteria from the International Consensus Meeting. The Kaplan-Meier method was used to illustrate the unadjusted 14-year cumulative rates of revision. A Cox regression model was used to report hazard for revision owing to PJI. Results were adjusted for previous non-arthroplasty surgery, sex, diagnosis, and age. RESULTS: Revision was performed in 88 shoulders (4.0%), of which 40 (1.8%) underwent revision owing to PJI. There were 272 patients (12.3%) who underwent previous rotator cuff repair, of whom 11 (4.0%) underwent revision owing to PJI. The 14-year cumulative rate of revision owing to PJI was 14.1% for patients with previous rotator cuff repair and 2.7% for patients without previous surgery. The adjusted hazard ratio for revision owing to PJI for patients with previous rotator cuff repair was 2.2 (95% confidence interval, 1.04-4.60) compared with patients without previous surgery. CONCLUSION: There is an increased risk of revision owing to PJI after RSA for patients with previous rotator cuff repair. We recommend that patients with previous rotator cuff repair be regarded as high-risk patients when considering RSA.

Elbow hemiarthroplasty vs. open reduction internal fixation for acute Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) type 13C fractures-A systematic review.

Background: Open reduction and internal fixation (ORIF) is the standard treatment for multifragmentary intra-articular distal humeral fractures. Fractures not amenable by ORIF are treated with total elbow arthroplasty (TEA). In recent years, elbow hemiarthroplasty (EHA) has been used as an alternative to TEA, as weight bearing restrictions and risk of component loosening are lower. We systematically reviewed the literature reporting functional outcomes and complication rates after either EHA or ORIF for Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) type 13C fractures. Methods: We searched PubMed, Embase, The Cochrane Library, and Scopus. The inclusion criteria were at least 5 patients, aged ≥50 years, AO/OTA type 13C fracture treated with ORIF or EHA, and evaluation with the Mayo Elbow Performance Score. Literature screening and data extraction were conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. The results were synthesized qualitatively using weighted means. No comparative statistical analyses were done. Results: We included 27 articles, which included 96 patients treated with EHA and 535 patients treated with ORIF. We identified 1 randomized controlled trial and 26 case series. The weighted mean Mayo Elbow Performance Score was 86.9 (n = 89) in the EHA group and 84.7 (n = 535) in the ORIF group. There were 26 (33%) complications (n = 78) in the EHA group and 103 (38%) complications (n = 270) in the ORIF group. Complication rates were generally high in both groups. Conclusion: We found comparable results of EHA and ORIF, which indicate that EHA is a viable treatment option for AO/OTA type 13C fractures not amenable by ORIF. Because of high risk of bias, interpretation of the results should be done with caution.

Implant migration and functional outcome of Reverse Shoulder Lateralized Glenosphere Line Extension System: a study protocol for a randomized controlled trial.

BACKGROUND: Inferior scapular notching is a complication unique to reverse shoulder arthroplasty. The most efficient technique to avoid inferior scapular notching has been reported to be lateralization of the glenoid offset. This study aims to compare radiological and functional outcomes of the DELTA Xtend® Reverse Shoulder System Lateralized Glenosphere Line Extension (intervention group) with the Standard DELTA Xtend® Reverse Shoulder System (control group). We hypothesize that the lateralization improves the patient outcome by decreasing the risk of inferior scapular notching without increasing the risk of migration and loosening of glenoid component. METHODS: In this randomized controlled trial, all Danish citizens with rotator cuff arthropathy or degeneration of the glenohumeral joint with severe posterior wear and allocated for a reverse total shoulder arthroplasty at the department of orthopaedic surgery at Herlev and Gentofte Hospital, Copenhagen University Hospital, will be considered for participation. The exclusion criteria are as follows: below 50 years of age, cognitive or linguistic impairment, insufficient glenoid bone stock, previous fracture in the upper extremity and autoimmune-mediated inflammatory arthritis. There will be included a total of 122 patients of which 56 will participate in the radiostereometric analysis. This number of patients allows 20% to drop out. The co-primary outcomes are the pattern and magnitude of the migration of the glenoid component assessed by radiostereometric analysis and the Western Ontario Osteoarthritis of the Shoulder index. The secondary outcomes are inferior scapular notching, patient-reported and functional outcomes (Oxford shoulder score, Constant-Murley score and pain), side effects and complications, changes in bone mineral density and economy. The included patients will be examined before the surgery, within 1 week and 3, 6, 12 and 24 months after. DISCUSSION: No previous studies have compared the conventional reverse shoulder arthroplasty with the lateralized reverse shoulder arthroplasty in a randomized controlled trial regarding migration and functional outcome. Furthermore, radiostereometric analysis has not been used to evaluate the migration of reverse shoulder arthroplasty in a randomized controlled trial. This study intends to determine which treatment has the most optimal outcome for the benefit of future patients with an indication for reverse shoulder arthroplasty. TRIAL REGISTRATION: The study has been notified to Pactius and has approval number P-2021-231. Furthermore, the study will be registered on Clinicaltrials.gov before starting the inclusion.

Previous surgery for instability is a risk factor for a worse patient-reported outcome after anatomical shoulder arthroplasty for osteoarthritis: a Danish nationwide cohort study of 3,743 arthroplasties.

BACKGROUND AND PURPOSE: Although most patients have good outcomes after shoulder arthroplasty for osteoarthritis, certain risk factors may lead to disappointing outcomes. We assessed risk factors for a worse outcome after anatomical shoulder arthroplasty for osteoarthritis. Our hypothesis was that previous surgery for instability would be a risk factor for a worse outcome independent of age, sex, and arthroplasty type. PATIENTS AND METHODS: We included arthroplasties reported to the Danish Shoulder Arthroplasty Registry between 2006 and 2018 (n = 3,743). The Western Ontario Osteoarthritis of the Shoulder (WOOS) index at 1 year was used as outcome. The total score was converted to a percentage of a maximum score. The general linear model was used to analyze differences in WOOS. Age, sex, arthroplasty type, and previous surgery were included in the multivariate model. Estimates were given with 95% confidence intervals (CI). RESULTS: The mean WOOS score was 78 for patients with no previous surgery and 55 for patients with surgery for instability. The mean difference was -16 (CI -10 to -22) in the multivariate model. Hemiarthroplasty had a worse outcome compared with total shoulder arthroplasty and young patients had a worse outcome compared with older patients. The mean differences in the multivariate model were -12 (CI -10 to -14) and -11 (CI -8 to -14) respectively. INTERPRETATION: Patients with previous surgery for instability had worse results independent of age, sex, and arthroplasty type and should be informed about their individual risk of a worse outcome.

Good long-term patient-reported outcome after shoulder arthroplasty for cuff tear arthropathy.

BACKGROUND: The use of the reverse shoulder arthroplasty (RSA) for cuff tear arthropathy (CTA) has increased within the last decades, but there is still limited information about the long-term outcome and how it performs in comparison with hemiarthroplasty (HA). The aim of this study was to compare the long-term patient-reported outcomes of RSA and HA for CTA. METHODS: We included all patients with CTA, who according to the Danish Shoulder Arthroplasty Registry, underwent either HA or RSA between 2006 and 2010. Patients who were alive were sent the Western Ontario Osteoarthritis of the Shoulder (WOOS) questionnaire in 2020. One hundred twenty (65%) patients returned a complete questionnaire. The linear regression model was used to compare RSA and HA. Sex, age, and previous surgery were included in the multivariable model. RESULTS: Forty-two HAs and 78 RSAs were evaluated with a mean follow-up time of 11.5 and 10.6 years, respectively. The mean WOOS score was 66.7 for HA and 71.7 for RSA. The difference of 5.0 was neither statistically significant nor clinically important (95% confidence interval: -4.3 to 14.2, P = .17), nor were there any significant risk of a worse WOOS score for sex, age, or previous surgery. CONCLUSION: To our knowledge, this is the first study to compare the long-term patient-reported outcomes of HA and RSA for CTA. Our results indicate that RSA is a reliable and durable treatment option for CTA with good long-term results. Based on this observational study, it is not possible to make safe estimates about the effect of RSA compared with HA, but similar to RSA, HA was associated with relatively good long-term results.

Good functional outcomes after open reduction and internal fixation for AO/OTA type 13-C2 and -C3 acute distal humeral fractures in patients aged over 45 years.

BACKGROUND: The purpose of this study was to report the functional outcomes and complications after open reduction and internal fixation (ORIF) for Arbeitsgemeinschaft für Osteosynthesefragen (AO)/Orthopaedic Trauma Association (OTA) type 13-C2 and -C3 acute distal humeral fractures with minimum 2-year follow-up. Our hypothesis was that ORIF would provide functional outcomes that are comparable to those of total elbow arthroplasty and elbow hemiarthroplasty reported in the literature. MATERIALS AND METHODS: During a 6-year period, 23 patients aged > 45 years were treated with double plating for AO/OTA type 13-C2 or -C3 fractures. The mean age was 62 years (range, 46-80 years). The Oxford Elbow Score was used as the primary outcome; the Mayo Elbow Performance Score, pain severity score (on a visual analog scale), range of motion, reoperations, and complications were used as secondary outcomes. RESULTS: The median Oxford Elbow Score was 42 (range, 25-48), where a score of 48 represents a normal elbow; 20 patients achieved good to excellent outcomes, and 3 achieved fair outcomes. The median Mayo Elbow Performance Score was 85 (range, 60-100), where a score of 100 represents a normal elbow; 18 patients achieved good to excellent outcomes, and 5 achieved fair outcomes. The median visual analog scale score was 2 (range, 0-5). The median flexion-extension and supination-pronation arcs were 120° (range, 70°-155°) and 160° (range, 75°-170°), respectively. Eight complications were recorded in 7 patients; 4 of them required reoperation because of fracture pseudarthrosis or elbow stiffness. Ten patients were working at the time of trauma, and nine of them returned to the same occupation. Our results are comparable to the results of previously published studies regarding the outcome of ORIF, elbow hemiarthroplasty, or total elbow arthroplasty for AO/OTA type 13-C fractures. CONCLUSION: ORIF is a reliable treatment option for AO/OTA type 13-C2 and -C3 acute distal humeral fractures in middle-aged and elderly patients, despite the considerable rate of complications. Good to excellent results can be obtained in most patients.

Ten-year follow-up of stemmed hemiarthroplasty for acute proximal humeral fractures.

AIMS: There is no consensus on the treatment of proximal humeral fractures. Hemiarthroplasty has been widely used in patients when non-surgical treatment is not possible. There is, despite extensive use, limited information about the long-term outcome. Our primary aim was to report ten-year patient-reported outcome after hemiarthroplasty for acute proximal humeral fractures. The secondary aims were to report the cumulative revision rate and risk factors for an inferior patient-reported outcome. METHODS: We obtained data on 1,371 hemiarthroplasties for acute proximal humeral fractures from the Danish Shoulder Arthroplasty Registry between 2006 and 2010. Of these, 549 patients (40%) were alive and available for follow-up. The Western Ontario Osteoarthritis of the Shoulder (WOOS) questionnaire was sent to all patients at nine to 14 years after primary surgery. Revision rates were calculated using the Kaplan-Meier method. Risk factors for an inferior WOOS score were analyzed using the linear regression model. RESULTS: Mean age at surgery was 67 years (24 to 90) and 445 (81%) patients were female. A complete questionnaire was returned by 364 (66%) patients at a mean follow-up of 10.6 years (8.8 to 13.8). Mean WOOS score was 64 (4.3 to 100.0). There was no correlation between WOOS scores and age, sex, arthroplasty brand, or year of surgery. The 14-year cumulative revision rate was 5.7% (confidence interval 4.1 to 7.2). Patients aged younger than 55 years and patients aged between 55 to 74 years had 5.6-times (2.0 to 9.3) and 4.3-times (1.9 to 16.7) higher risk of revision than patients aged older than 75 years, respectively. CONCLUSION: This is the largest long-term follow-up study of acute proximal humeral fractures treated with hemiarthroplasty. We found a low revision rate and an acceptable ten-year patient-reported outcome. The patient-reported outcome should be interpreted with caution as we have no information about the patients who died or did not return a complete WOOS score. The long-term outcome and revision rate suggest that hemiarthroplasty offers a valid alternative when non-surgical treatment is not possible. Cite this article: Bone Joint J 2021;103-B(6):1063-1069.

Early migration of stemless and stemmed humeral components after total shoulder arthroplasty for osteoarthritis-study protocol for a randomized controlled trial.

BACKGROUND: Glenohumeral osteoarthritis can, in the most severe cases, require surgery with insertion of a shoulder arthroplasty. A design with a stem in the humeral bone canal is currently regarded as the standard treatment option in patients who have an intact rotator cuff function, but complications related to the stem including humeral fractures can have devastating consequences. By using a stemless humeral component, stem-related complications can be reduced. The aim of this study is to compare the Comprehensive Nano stemless total shoulder arthroplasty (intervention group) with the Comprehensive stemmed total shoulder arthroplasty (control group). MATERIALS AND METHODS: This is a randomized controlled trial comparing the stemless and the stemmed total shoulder arthroplasty. All Danish citizens with glenohumeral osteoarthritis indicating a total shoulder arthroplasty referred to the orthopedic department at Copenhagen University Hospital in Herlev/Gentofte will be offered participation. The following exclude from participation: below 18 years of age, cognitive or linguistic impairment, insufficient function of the rotator cuff, poor bone quality, and ASA groups 4-5. A total of 122 patients will be included of which 56 will be part of a radiostereometric analysis (RSA) study of humeral component migration. The primary outcomes are magnitude of migration of the humeral component assessed by RSA and patient-reported outcome by Western Ontario Osteoarthritis of the Shoulder index (WOOS). The secondary outcomes are additional patient-reported outcomes, functional outcome, readmission, complications, revisions, and changes in bone mineral density (BMD) of the proximal humerus assessed by duel energy x-ray absorptiometry (DXA) and economy (cost-utility analysis). The patients are examined before the operation and 3, 6, 12, and 24 months postoperative. DISCUSSION: To our knowledge, RSA has never been used to access migration of a stemmed or a stemless humeral component nor has the stemmed and the stemless humeral component been compared with regard to pain relief and shoulder function in a randomized clinical trial. Today, the two designs are considered equal in the treatment of osteoarthritis. The study will provide surgeons and patients with information about shoulder arthroplasty for osteoarthritis and assist them in decision-making. TRIAL REGISTRATION: ClinicalTrials.gov NCT04105478 . Registered on 25 September 2019.

Elbow hemiarthroplasty versus open reduction and internal fixation for AO/OTA type 13 C2 and C3 fractures of distal humerus in patients aged 50 years or above: a randomized controlled trial.

BACKGROUND: Intraarticular distal humeral fractures of AO/OTA type 13 C2 and C3 pose a surgical challenge despite the evolution of surgical implants and techniques. Open reduction and internal fixation (ORIF) is often preferred as the first choice of treatment, but the results vary and are sometimes disappointing. Total elbow arthroplasty (TEA) has been widely used for fractures that are not amenable to ORIF in elderly patients, but the mechanical complications remain a challenge, especially in active patients. Elbow hemiarthroplasty (EHA) provides a modern alternative that might avoid the mechanical complications and weight bearing restrictions related to the linked articulation in semi-constrained TEA. No studies have compared the results of EHA to that of ORIF, but case series have reported promising results. METHODS/DESIGN: This is a study protocol describing an investigator-initiated, non-blinded randomized controlled trial comparing the outcome of EHA with ORIF for AO/OTA type 13 C2 and C3 fractures of the distal humerus in patients who are 50 years or older. Forty-four patients with AO/OTA type 13 C2 and C3 fractures of distal humerus will be randomized to either EHA or ORIF. The Oxford Elbow Score (OES) will be used as primary outcome. Mayo Elbow Performance Score (MEPS), pain severity score (VAS), range of motion, and patient satisfaction will be used as secondary outcomes. Reoperations, complications, and the length of sick leave will be recorded. The patients will be examined after the operation and at 3 months and 1, 2, 5, and 10 years. DISCUSSION: The main objective of this study is to investigate the best treatment option for AO/OTA type 13 C2 and C3 fractures of distal humerus in patients aged 50 years or above. We hypothesize that EHA results in fewer complications and superior functional outcome compared with ORIF and that the mechanical complications related to the linked articulation of TEA can be avoided. TRIAL REGISTRATION: ClinicalTrials.gov, PRS, NCT04163172. Registered November 13, 2019. https://clinicaltrials.gov/ct2/results?cond=&term=evori&cntry=&state=&city=&dist= (Table 2). The protocol has been approved by The Scientific Ethics Committee of the Capital Region of Denmark (Jr. no.: H- 19,035,590). The processing of personal data has been approved by the Danish Data Protection Agency (Jr. no. P-2019-246). Inclusion started on February 1, 2020.

Low risk of revision after reverse shoulder arthroplasty for acute proximal humeral fractures.

BACKGROUND: Reverse shoulder arthroplasty (RSA) has gained popularity in the treatment of proximal humeral fractures (PHFs), especially in elderly patients. The purpose of this study was to investigate the use of RSA implants for acute PHFs and risk of revision, as well as risk factors for revision. METHODS: RSA implants for acute PHFs were identified from the Nordic Arthroplasty Register Association registry data from 2004 to 2016. Kaplan-Meier survival analysis was used to calculate implant survival. Cox multiple regression analysis was used to calculate the adjusted revision rate for sex, age, country of operation, and year of surgery. RESULTS: The study included 1523 RSA implants for PHFs (84% women; average age, 77 years; average follow-up time, 2.5 years). The 5-year cumulative implant survival rate was 97% (confidence limits, 95.5% and 98%). Revision was performed for 33 implants (2%). The most common reason for revision was instability, occurring in 11 cases (0.7%), followed by fracture, occurring in 6 (0.4%), and infection, occurring in 5 (0.3%). Four different arthroplasty brands were used in this cohort, with the Delta Xtend in two-thirds of cases (n = 1025). Age younger than 60 years and male sex were associated with slightly higher rates of revision; however, these differences did not reach statistical significance (hazard ratio of 2.02 with P = .075 and hazard ratio of 3.23 with P = .057, respectively). CONCLUSION: The use of RSA for acute PHFs is increasing in the Nordic countries. The short-term risk of revision is low. The main reason for revision of RSA for this indication is instability.

What Factors are Associated with Revision or Worse Patient-reported Outcome after Reverse Shoulder Arthroplasty for Cuff-tear Arthropathy? A Study from the Danish Shoulder Arthroplasty Registry.

BACKGROUND: Reverse shoulder arthroplasty has been proven to improve function in shoulders with cuff-tear arthropathy, but existing studies are primarily single-center studies with a small number of patients, which limits their ability to identify patients who have an increased risk of revision or a worse functional outcome. QUESTIONS/PURPOSES: (1) What is the estimated 10-year cumulative revision rate after reverse shoulder arthroplasty for cuff-tear arthropathy, and what factors are associated with the risk of revision? (2) What is the patient-reported outcome 1 year after surgery, and what factors are associated with a worse patient-reported outcome? METHODS: We included all patients treated with reverse shoulder arthroplasty for cuff-tear arthropathy reported in the Danish Shoulder Arthroplasty Registry from 2006 to 2015. During the study period, the completeness of reporting was 93% for both primary and revision arthroplasties. Estimated revision rates were illustrated using the Kaplan-Meier method, and hazard ratios were calculated using a Cox regression model. Patient-reported outcome was measured with a postal survey at 12 months (range 10-14 months) postoperatively using the Western Ontario Osteoarthritis of the Shoulder (WOOS) index. The WOOS is a patient-administered questionnaire that measures the quality of life of patients with glenohumeral osteoarthritis. A visual analog scale that ranges from 0 to 100 is used for each question. There are 19 questions, giving a total score ranging from 0 to 1900, with 1900 being the worst. For simplicity of presentation, raw scores were converted to a percentage of the maximum score, with 100 being the best. There is no defined minimal clinically important difference of the WOOS, but the Danish Shoulder arthroplasty registry has for many years regarded an arbitrary difference of 10 or above as being clinically relevant. The rate of response to the WOOS was 71%. RESULTS: The estimated 10-year cumulative revision rate was 8.5% (95% confidence interval, 5.7%-11.3%) with differences between the arthroplasty model (21.0%; 95% CI, 11.8% to 30.8% for the Delta Mark III and 5.5%; 95% CI, 3.7% to 7.3% for the Delta Xtend) and gender (6.0%; 95% CI, 3.0% to 9.0% for women and 13.1%; 95% CI, 7.1% to 19.1% for men). After controlling for potential confounding variables including gender, previous surgery, arthroplasty model, and period of surgery, the risk of revision was higher with the Delta Mark III than with the Delta Xtend (hazard ratio 2.7; 95% CI, 1.3 to 5.4; p < 0.01) and higher in men than in women (hazard ratio 2.7; 95% CI, 1.6 to 4.7; p < 0.01). Thirty-three percent (19 of 57) of the revision arthroplasties were performed for dislocation and 32% (18 of 57) were to treat periprosthetic joint infection. After controlling for confounding variables, only previous surgery was associated with a worse WOOS score (mean difference -10.6; 95% CI, -15.2 to -5.9; p < 0.01); there were no associations between a worse score and gender, arthroplasty model, age group, or period of surgery. CONCLUSIONS: The results from the present study can be used to inform patients about their individual risk of revision or a disappointing functional outcome. The study also demonstrates the need for proper patient selection and attention to technical details to reduce the risk of revision, especially for men. Our follow-up time was, however, short, with only an estimate of the 10-year revision rate. Future studies with a long-term follow-up duration are needed to confirm our results. LEVEL OF EVIDENCE: Level III, therapeutic study.

The benefits of collaboration: the Nordic Arthroplasty Register Association.

The Nordic Arthroplasty Register Association (NARA) was established in 2007 by arthroplasty register representatives from Sweden, Norway and Denmark with the overall aim to improve the quality of research and thereby enhance the possibility for quality improvement with arthroplasty surgery. Finland joined the NARA collaboration in 2010.NARA minimal hip, knee and shoulder datasets were created with variables that all countries can deliver. They are dynamic datasets, currently with 25 variables for hip arthroplasty, 20 for knee arthroplasty and 20 for shoulder arthroplasty.NARA has published statistical guidelines for the analysis of arthroplasty register data. The association is continuously working on the improvement of statistical methods and the application of new ones.There are 31 published peer-reviewed papers based on the NARA databases and 20 ongoing projects in different phases. Several NARA publications have significantly affected clinical practice. For example, metal-on-metal total hip arthroplasty and resurfacing arthroplasty have been abandoned due to increased revision risk based on i.a. NARA reports. Further, the use of uncemented total hip arthroplasty in elderly patients has decreased significantly, especially in Finland, based on the NARA data.The NARA collaboration has been successful because the countries were able to agree on a common dataset and variable definitions. The collaboration was also successful because the group was able to initiate a number of research projects and provide answers to clinically relevant questions. A number of specific goals, set up in 2007, have been achieved and new one has emerged in the process. Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180058.

Increased use of total shoulder arthroplasty for osteoarthritis and improved patient-reported outcome in Denmark, 2006-2015: a nationwide cohort study from the Danish Shoulder Arthroplasty Registry.

Background and purpose - Osteoarthritis has become the most common indication for shoulder arthroplasty in Denmark, and the treatment strategies have changed towards the use of anatomical total shoulder arthroplasty and reverse shoulder arthroplasty. We investigated whether changes in the use of arthroplasty types have changed the overall patient-reported outcome from 2006 to 2015. Patients and methods - We included 2,867 shoulder arthroplasties performed for osteoarthritis between 2006 and 2015 and reported to the Danish Shoulder Arthroplasty Registry. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index at 1 year was used as patient-reported outcome. The raw score was converted to a percentage of a maximum score. General linear models were used to analyze differences in WOOS. Results - The proportion of anatomical total shoulder arthroplasty and reverse shoulder arthroplasty increased from 3% and 7% in 2006 to 53% and 27% in 2015. The mean WOOS score was 70 (SD 26) after resurfacing hemiarthroplasties (n = 1,258), 68 (SD 26) after stemmed hemiarthroplasty (n = 500), 82 (SD 23) after anatomical total shoulder arthroplasties (n = 815), and 74 (SD 23) after reverse shoulder arthroplasties (n = 213). During the study period, the overall WOOS score increased with 18 (95% CI 12-22) in the univariate model and 10 (CI 5-15) in the multivariable model, and the WOOS scores for anatomical total shoulder arthroplasty increased by 14 (CI 5-23). Interpretation - We found an increased WOOS score from 2006 to 2015, which was primarily related to a higher proportion of anatomical total shoulder arthroplasty and reverse shoulder arthroplasty towards the end of the study period, and to improved outcome of anatomical total shoulder arthroplasty.

The short-term survival of total stemless shoulder arthroplasty for osteoarthritis is comparable to that of total stemmed shoulder arthroplasty: a Nordic Arthroplasty Register Association study.

BACKGROUND: The purpose of this study was to compare the short-term survival rate of total stemless, metaphyseal fixated, shoulder arthroplasty with that of total stemmed shoulder arthroplasty in the treatment of osteoarthritis. METHODS: Data were collected by the national arthroplasty registries in Denmark, Finland, Norway, and Sweden and merged into 1 dataset under the umbrella of the Nordic Arthroplasty Register Association. For the present study, we included all patients with osteoarthritis treated with either stemless (n = 761) or stemmed (n = 4398) shoulder arthroplasty from 2011 to 2016. RESULTS: A total of 21 (2.8%) stemless and 116 (2.6%) stemmed shoulder arthroplasties were revised. The 6-year unadjusted cumulative survival rates were 0.953 for stemless shoulder arthroplasty and 0.958 for stemmed shoulder arthroplasty, P = .77. The most common indication for revision of both arthroplasty types was infection. Five (0.7%) stemless and 16 (0.4%) stemmed shoulder arthroplasties were revised because of loosening of either the glenoid or the humeral component. In the multivariate cox regression model, which included age, category, gender, year of surgery, previous surgery, and arthroplasty type, the hazard ratio (HR) for revision of the stemless shoulder arthroplasty was 1.00 (95% confidence interval [CI], 0.63-1.61), P = .99, with the stemmed shoulder arthroplasty as reference. Male gender (HR = 1.50 [95% CI, 1.06-2.13], P = .02) and previous surgery (HR = 2.70 [95% CI, 1.82-4.01], P < .001) were associated with increased risk of revision. CONCLUSION: The short-term survival of total stemless shoulder arthroplasty appears comparable with total stemmed shoulder arthroplasty, but longer observation time is needed to confirm whether they continue to perform equally.

Low revision rate despite poor functional outcome after stemmed hemiarthroplasty for acute proximal humeral fractures: 2,750 cases reported to the Danish Shoulder Arthroplasty Registry.

Background and purpose - The revision rate of stemmed hemiarthroplasty (SHA) for acute proximal humeral fractures is low, but does not necessarily reflect the functional outcome. We report the revision rate of SHA for acute proximal humeral fractures and the proportion of arthroplasties that are not revised despite low functional outcome scores. Patients and methods - The Danish Shoulder Arthroplasty Registry was used to identify all patients with a proximal humeral fracture that was treated with a SHA between January 1, 2006 and December 31, 2015. Information on demographics, surgical procedures, and revisions was collected by the registry. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index at 1 year was used as functional outcome score. We converted the score to a percentage of a maximum score with 100 being the best. Results - 2,750 SHAs in 2,719 patients were included. Mean age was 72 years (SD 11); 79% were women. Mean WOOS at 1 year was 55 (SD 26). A total of 101 (4%) arthroplasties were revised, and the 10-year cumulative implant survival rate was 95%. The Cox regression model showed a statistically significant impact on implant survival of age, but not of sex or arthroplasty brand. A WOOS score below 30 and 50 was reported in 11% and 25% of patients, respectively. Interpretation - We found a high implant survival rate, but also a high proportion of patients with a low functional outcome score 1 year after surgery.

Good outcome after elbow hemiarthroplasty in active patients with an acute intra-articular distal humeral fracture.

BACKGROUND: This study reported the clinical outcomes and complications after elbow hemiarthroplasty (EHA) for acute distal humeral fractures Arbeitsgemeinschaft für Osteosynthesefragen (AO)/Orthopaedic Trauma Association (OTA) type C2 and C3. METHOD: During a 6-year period, 24 active patients with acute intra-articular and multifragmentary distal humeral fractures were treated with an EHA by 1 of 4 experienced elbow surgeons. Mean age was 65 years (range, 47-80 years). Median follow-up time was 20 months (range, 12-70 months). RESULTS: The median Oxford Elbow Score was 40 points (range, 17-48 points), where 48 points represents a normal elbow. Outcomes were "good to excellent results" in 21 patients, "fair" in 2 patients, and "poor" in 1 patient. The median Mayo Elbow Performance Score was 85 points (range, 50-100 points), where 100 points represents a normal elbow. Outcomes were "good to excellent" in 19 patients, "fair" in 4 patients, and "poor" in 1 patient. The median pain severity score was 2 (range, 0-7) in a scale from 0 to 10 where 0 represents a pain-free elbow. The median flexion/extension and supination/pronation arcs were 110° (range, 60°-140°) and 160° (range, 115°-180°), respectively. Complications were recorded in 7 patients, and 3 of them underwent reoperation because of stiffness, which was treated with open release. CONCLUSIONS: EHA provides a good and reliable option in the treatment of an acute intra-articular distal humeral fracture unsuitable for open reduction and internal fixation, especially in active patients.

Poor patient-reported outcome after shoulder replacement in young patients with cuff-tear arthropathy: a matched-pair analysis from the Danish Shoulder Arthroplasty Registry.

Background and purpose - Reverse shoulder arthroplasty (RSA) has become the treatment of choice for cuff-tear arthropathy. There are, however, concerns about the longevity and the outcome of an eventual revision procedure. Thus, resurfacing hemiarthroplasty (RHA) with extended articular surface has been suggested for younger patients. We compared the patient-reported outcome of these arthroplasty designs for cuff-tear arthropathy. Patients and methods - We included patients operated on because of cuff-tear arthropathy and reported to the Danish Shoulder Arthroplasty Registry (DSR) from January 1, 2006 to December 31, 2013. 117 RHA cases were matched by age and sex with 233 RSA controls. 34 of the RHAs were conventional and 67 were RHAs with extended articular surface. The Western Ontario Osteoarthritis of the Shoulder (WOOS) Index at 1 year was used as primary outcome. The score was converted to a percentage of a maximum score. Revision, defined as removal or exchange of any component or the addition of a glenoid component, was used as secondary outcome. Results - Median WOOS was 49 (30-81) for RHA and 77 (50-92) for RSA (p < 0.001). For patients younger than 65 years, median WOOS was 58 (44-80) after RHA, similar to the 54 after RSA (37-85). For patients older than 65 years, median WOOS was 48 (28-82) after RHA and 79 (55-92) after RSA (p < 0.001). Interpretation - In all patients RSA had a clinically and statistically better patient-reported outcome than RHA. However, in patients younger than 65 years the functional outcome was similar and poor for either arthroplasty type. The optimal treatment of CTA in young patients remains a challenge.