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.

Patients undergoing shoulder arthroplasty for failed nonoperative treatment of proximal humerus fracture have low implant survival and low patient-reported outcomes: 837 cases from the Danish Shoulder Arthroplasty Registry.

Background and purpose - When nonoperative treatment of proximal humerus fracture (PHF) fails, shoulder arthroplasty may be indicated. We investigated risk factors for revision and evaluated patient-reported outcome 1 year after treatment with either stemmed hemiarthroplasty (SHA) or reverse total shoulder arthroplasty (RTSA) after previous nonoperative treatment of PHF sequelae.Patients and methods - Data were derived from the Danish Shoulder Arthroplasty Registry and included 837 shoulder arthroplasties performed for PHF sequelae between 2006 and 2015. Type of arthroplasty, sex, age, and surgery period were investigated as risk factors. The Western Ontario Osteoarthritis of the Shoulder index (WOOS) was used to evaluate patient-reported outcome (0-100, 0 indicates worst outcome). Cox regression and linear regression models were used in the statistical analyses.Results - 644 patients undergoing SHA and 127 patients undergoing RTSA were included. During a mean follow-up of 3.7 years, 48 (7%) SHA and 14 (11%) RTSA were revised. Men undergoing RTSA had a higher revision rate than men undergoing SHA (hazard ratio [HR] 6, 95% confidence interval [CI] 2-19). 454 (62%) patients returned a complete WOOS questionnaire. The mean WOOS score was 53 for SHA and 53 for RTSA. Patients who were 65 years or older had a better WOOS score than younger patients (mean difference 7, CI 1-12). Half of patients had WOOS scores below 50.Interpretation - Shoulder arthroplasty for PHF sequelae was associated with a high risk of revision and a poor patient-reported outcome. Men treated with RTSA had a high risk of revision.

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.

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.

Mortality after shoulder arthroplasty: 30-day, 90-day, and 1-year mortality after shoulder replacement--5853 primary operations reported to the Danish Shoulder Arthroplasty Registry.

BACKGROUND: The primary aim was to quantify the 30-day, 90-day, and 1-year mortality rates after primary shoulder replacement. The secondary aims were to assess the association between mortality and diagnoses and to compare the mortality rate with that of the general population. METHODS: The study included 5853 primary operations reported to the Danish Shoulder Arthroplasty Registry between 2006 and 2012. Information about deaths was obtained from the Danish Cause of Death Register and the Danish Civil Registration System. Age- and sex-adjusted control groups were retrieved from Statistics Denmark. RESULTS: The mean age was 69.3 ± 11.6 years, and 69.2% of patients were women. Of the patients, 39 (0.7%) died within 30 days, 88 (1.5%) within 90 days, and 222 (3.8%) within 1 year. Fracture patients had an incidence rate of 1256 per 100,000 within 30 days, which was significantly higher than the incidence rate of 182 per 100,000 in the general population (P < .001), whereas osteoarthritis patients had an incidence of 111 per 100,000, which was significantly lower than the incidence rate of 125 per 100,000 in the general population. CONCLUSIONS: Fracture patients had a 6 times higher incidence of death within 30 days than the general population. However, the difference was equalized during the first year. This finding indicates that the injury and arthroplasty procedure are associated with an increased risk of death for these patients. Pulmonary, cardiac, and abdominal causes of death were common, and for fracture patients in particular, close postoperative monitoring of pulmonary, cardiac, and abdominal conditions seems important.

High rate of clinically relevant improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis.

BACKGROUND: The minimal clinically important difference (MCID) is defined as the smallest meaningful change in a health domain that a patient would identify as important. Thus, an improvement that exceeds the MCID can be used to define a successful treatment for the individual patient. AIM: To quantify the rate of clinical improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis. METHODS: Patients were treated with the Global Unite total shoulder platform arthroplasty between March 2017 and February 2019 at Herlev and Gentofte Hospital, Denmark. The patients were evaluated preoperatively and 3 months, 6 months, 12 months, and 24 months postoperatively using the Western Ontario Osteoarthritis of the Shoulder index (WOOS), Oxford Shoulder Score (OSS) and Constant-Murley Score (CMS). The rate of clinically relevant improvement was defined as the proportion of patients who had an improvement 24 months postoperatively that exceeded the MCID. Based on previous literature, MCID for WOOS, OSS, and CMS were defined as 12.3, 4.3, and 12.8 respectively. RESULTS: Forty-nine patients with a Global Unite total shoulder platform arthroplasty were included for the final analysis. Mean age at the time of surgery was 66 years (range 49.0-79.0, SD: 8.3) and 65% were women. One patient was revised within the two years follow-up. The mean improvement from the preoperative assessment to the two-year follow-up was 46.1 points [95% confidence interval (95%CI): 39.7-53.3, P < 0.005] for WOOS, 18.2 points (95%CI: 15.5-21.0, P < 0.005) for OSS and 37.8 points (95%CI: 31.5-44.0, P < 0.005) for CMS. Two years postoperatively, 41 patients (87%) had an improvement in WOOS that exceeded the MCID, 45 patients (94%) had an improvement in OSS that exceeded the MCID, and 42 patients (88%) had an improvement in CMS that exceeded the MCID. CONCLUSION: Based on three shoulder-specific outcome measures we find that approximately 90% of patients has a clinically relevant improvement. This is a clear message when informing patients about their prognosis.

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.

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.

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.

Minimal Clinically Important Differences (MCID) for the Western Ontario Osteoarthritis of the Shoulder Index (WOOS) and the Oxford Shoulder Score (OSS).

BACKGROUND: The minimal clinically important difference (MCID) is an important instrument in the interpretation of changes in patient-reported outcome measures (PROM). To our knowledge, no MCID of the Western Ontario Osteoarthritis of the Shoulder Index (WOOS) score has ever been reported and no studies have reported an MCID for the Oxford Shoulder Score (OSS) based on patients with glenohumeral osteoarthritis, treated with an anatomical total shoulder arthroplasty (aTSA). The aim of this study was to determine MCID for WOOS and OSS in a cohort of patients with glenohumeral osteoarthritis treated with an aTSA. METHODS: All patients treated with an aTSA for glenohumeral osteoarthritis at our institution between March 2017 and February 2019 were included. Each patient completed the WOOS and the OSS preoperatively and one year postoperatively. At one year, the patients were asked to rate their overall improvement on a 7-point scale. We used an anchor-based method as our primary method to calculate the MCID, supported by two different distribution-based methods. RESULTS: A total of 45 primary aTSA were included. The MCID of WOOS was 12.3 according to the anchor-based method and 14.2 and 10.3 according to the two distribution-based methods. The MCID of OSS was 4.3 according to the anchor-based method and 5.8 and 4.3 according to the two distribution-based methods. CONCLUSION: The anchor-based method is considered superior to the distribution-based method, and therefore we advocate to use this as MCID. For patients with glenohumeral osteoarthritis treated with an aTSA, the MCID values were 12.3 points for WOOS and 4.3 points for OSS. To our knowledge, this is the first study to report a MCID value for WOOS and the first study to report a MCID value for OSS in this subgroup of patients.