Session 11: Shoulder/Elbow
Fredag den 23. oktober
09:00 – 10:00
Lokale: Stockholm/Copenhagen
Chairmen: Bo S. Olsen / Jeppe V. Rasmussen
Alexander Amundsen, Jeppe V. Rasmussen, Stig Brorson, Bo Sanderhoff Olsen
Orthopaedic, Herlev Hospital
Background: Mortality and risk factors associated with shoulder arthroplasty has been sparsely reported compared to knee and hip arthroplasty.
Purpose / Aim of Study: The primary aim was to quantify the thirty-day, ninety-day and one-year mortality after primary shoulder arthroplasty and compare it to the general population. An assessment of the association between mortality, surgical diagnoses and causes of death was performed.
Materials and Methods: 5,853 primary operations from 2006 to 2012 were included and information about the patients was obtained from the Danish Shoulder Arthroplasty Register and the Danish Cause of Death Register. Incidences in the general population were calculated with data from Statistics Denmark and compared to the patients.
Findings / Results: The mean age was 69.3 (± 11.6) years and 69.2 % were women. Thirty-nine (0.7 %) patients died within thirty days, eighty-eight (1.5 %) within ninety days and 222 (3.8 %) within one year. Fracture patients had a higher mortality than patients with elective diagnoses. The overall incidence of death within thirty days was 666 per 100,000. Fracture patients had an over five times higher incidence of death than the general population within thirty days. Deaths occurring within thirty days were due to cardiac (20.5 %) and abdominal causes (20.5 %).
Conclusions: The mortality at thirty days (0.7 %), ninety-days (1.5 %) and one-year (3.8 %) was significantly higher than that of the general population. There was a trend that mortality rates balanced in the patients and the general population one year after shoulder arthroplasty. Fracture patients had higher mortality. Patients with osteoarthritis and rotator cuff arthropathy are relatively safe in terms of mortality when undergoing shoulder arthroplasty. Pulmonary, cardiac and abdominal causes of death were the most common in the short-term group.
Orthopaedic, Herlev Hospital
Background: Mortality and risk factors associated with shoulder arthroplasty has been sparsely reported compared to knee and hip arthroplasty.
Purpose / Aim of Study: The primary aim was to quantify the thirty-day, ninety-day and one-year mortality after primary shoulder arthroplasty and compare it to the general population. An assessment of the association between mortality, surgical diagnoses and causes of death was performed.
Materials and Methods: 5,853 primary operations from 2006 to 2012 were included and information about the patients was obtained from the Danish Shoulder Arthroplasty Register and the Danish Cause of Death Register. Incidences in the general population were calculated with data from Statistics Denmark and compared to the patients.
Findings / Results: The mean age was 69.3 (± 11.6) years and 69.2 % were women. Thirty-nine (0.7 %) patients died within thirty days, eighty-eight (1.5 %) within ninety days and 222 (3.8 %) within one year. Fracture patients had a higher mortality than patients with elective diagnoses. The overall incidence of death within thirty days was 666 per 100,000. Fracture patients had an over five times higher incidence of death than the general population within thirty days. Deaths occurring within thirty days were due to cardiac (20.5 %) and abdominal causes (20.5 %).
Conclusions: The mortality at thirty days (0.7 %), ninety-days (1.5 %) and one-year (3.8 %) was significantly higher than that of the general population. There was a trend that mortality rates balanced in the patients and the general population one year after shoulder arthroplasty. Fracture patients had higher mortality. Patients with osteoarthritis and rotator cuff arthropathy are relatively safe in terms of mortality when undergoing shoulder arthroplasty. Pulmonary, cardiac and abdominal causes of death were the most common in the short-term group.
Ann Ganestam, Mikkel Attrup, Per Hölmich, Kristoffer W Barfod
Orthopedic surgery, Hvidovre Hospital
Background: Shoulder problems constitute a major socioeconomic problem with lifetime prevalence up to 66.7%. To aid diagnosis more than 184 tests have been described. Although a standardized guideline for a complete shoulder examination is not available, we hypothesize that experienced shoulder surgeons have clear preferences among shoulder physical examination tests.
Purpose / Aim of Study: The aims of this study was to identify the most used shoulder physical examination tests for 12 selected shoulder pathologies and evaluate the usefulness of these tests in terms of sensitivity and specificity
Materials and Methods: In March to May 2014, ten experienced shoulder surgeons were asked to name the shoulder physical examination tests they would use for 12 pre-selected shoulder pathologies. A literature search on Pubmed.com and on the Cochrane library was conducted to assess the sensitivity and specificity of the most reported shoulder physical examination tests for each pathology to investigate specificity and sensitivity of the test
Findings / Results: In total 49 shoulder physical examination tests were named. For eight of 12 pathologies at least 9 surgeons reported at least one common shoulder physical examination test. Eight surgeons agreed on one test for one pathology. For the remaining three pathologies six surgeons recommended one common test. The sensitivity and specificities of the 12 chosen tests were acceptable.
Conclusions: There was a high degree of agreement on which shoulder physical examination to use for which shoulder pathology and the specificity and sensitivity of the most reported shoulder physical examination tests for each pathology were both acceptable. However, there is no clear evidence to support one shoulder physical examination test over another in the literature
Orthopedic surgery, Hvidovre Hospital
Background: Shoulder problems constitute a major socioeconomic problem with lifetime prevalence up to 66.7%. To aid diagnosis more than 184 tests have been described. Although a standardized guideline for a complete shoulder examination is not available, we hypothesize that experienced shoulder surgeons have clear preferences among shoulder physical examination tests.
Purpose / Aim of Study: The aims of this study was to identify the most used shoulder physical examination tests for 12 selected shoulder pathologies and evaluate the usefulness of these tests in terms of sensitivity and specificity
Materials and Methods: In March to May 2014, ten experienced shoulder surgeons were asked to name the shoulder physical examination tests they would use for 12 pre-selected shoulder pathologies. A literature search on Pubmed.com and on the Cochrane library was conducted to assess the sensitivity and specificity of the most reported shoulder physical examination tests for each pathology to investigate specificity and sensitivity of the test
Findings / Results: In total 49 shoulder physical examination tests were named. For eight of 12 pathologies at least 9 surgeons reported at least one common shoulder physical examination test. Eight surgeons agreed on one test for one pathology. For the remaining three pathologies six surgeons recommended one common test. The sensitivity and specificities of the 12 chosen tests were acceptable.
Conclusions: There was a high degree of agreement on which shoulder physical examination to use for which shoulder pathology and the specificity and sensitivity of the most reported shoulder physical examination tests for each pathology were both acceptable. However, there is no clear evidence to support one shoulder physical examination test over another in the literature
Birgit Juul-Kristensen, Elise Johannessen, Helle Reiten, Silje Maeland , Helene Løvaas
Institute of Sports Science and Clinical Biomechanics , University of Southern Denmark, Odense, DK; Institute of Occupational Therapy, Physiotherapy and Radiography, Bergen University College, Bergen, N; Institute of Occupational Therapy, Physiotherapy and Radiography , Bergen University College, Bergen, N; Uni Research Health, Bergen, N; Department of Physical Medicine and Rehabilitation, Haukeland University Hospital, Bergen, N
Background: The shoulder is a frequently reported pain area and associated with shoulder instability in patients with Joint Hypermobility Syndrome (JHS) and Ehlers Danlos-hypermobility type (EDS-HT). No studies have reported the nature of shoulder function in this group.
Purpose / Aim of Study: To investigate characteristics of shoulder function, pain and health related quality of life (HRQoL) in adults with JHS/EDS-HT, compared with the general population (controls).
Materials and Methods: Through postal survey 110 patients diagnosed with JHS/EDS-HT from two Norwegian hospitals, and 140 gender- and age-matched healthy controls from Statistics Norway were invited. Shoulder function from Western Ontario Shoulder Instability Index (WOSI), pain from Numerical Pain Rating Scale (NPRS) and pain drawing chart, in addition to HRQoL from the 36-item Short Form (SF-36) were registered.
Findings / Results: Totally, 81 individuals responded, with an overall response rate of 34% (JHS/EDS-HT: 53% vs. controls: 21%). JHS/EDS-HT had significantly lower shoulder function (WOSI total: 49.9 vs. 83.3; p<0.001), general physical function (SF-36, Physical Component scale: 28.1 vs 49.9; p<0.001), and higher pain intensity (NRS: 6.4 vs. 2.7; p<0.001) than controls. Further, JHS/EDS-HT more often reported generalized pain (96%). Neck and shoulder joints were most frequently rated as painful areas, with significantly higher frequency in JHS/EDS-HT than controls (90% vs 27%; 80.% vs 37%), for the neck and the shoulder, respectively.
Conclusions: Adults with JHS/EDS-HT have impaired shoulder function, increased pain intensity and more often generalized pain, as well as reduced physical HRQoL compared with the general population. Neck and shoulder joints were the most often painful areas in both groups, however, with significantly higher frequency in JHS/EDS-HT.
Institute of Sports Science and Clinical Biomechanics , University of Southern Denmark, Odense, DK; Institute of Occupational Therapy, Physiotherapy and Radiography, Bergen University College, Bergen, N; Institute of Occupational Therapy, Physiotherapy and Radiography , Bergen University College, Bergen, N; Uni Research Health, Bergen, N; Department of Physical Medicine and Rehabilitation, Haukeland University Hospital, Bergen, N
Background: The shoulder is a frequently reported pain area and associated with shoulder instability in patients with Joint Hypermobility Syndrome (JHS) and Ehlers Danlos-hypermobility type (EDS-HT). No studies have reported the nature of shoulder function in this group.
Purpose / Aim of Study: To investigate characteristics of shoulder function, pain and health related quality of life (HRQoL) in adults with JHS/EDS-HT, compared with the general population (controls).
Materials and Methods: Through postal survey 110 patients diagnosed with JHS/EDS-HT from two Norwegian hospitals, and 140 gender- and age-matched healthy controls from Statistics Norway were invited. Shoulder function from Western Ontario Shoulder Instability Index (WOSI), pain from Numerical Pain Rating Scale (NPRS) and pain drawing chart, in addition to HRQoL from the 36-item Short Form (SF-36) were registered.
Findings / Results: Totally, 81 individuals responded, with an overall response rate of 34% (JHS/EDS-HT: 53% vs. controls: 21%). JHS/EDS-HT had significantly lower shoulder function (WOSI total: 49.9 vs. 83.3; p<0.001), general physical function (SF-36, Physical Component scale: 28.1 vs 49.9; p<0.001), and higher pain intensity (NRS: 6.4 vs. 2.7; p<0.001) than controls. Further, JHS/EDS-HT more often reported generalized pain (96%). Neck and shoulder joints were most frequently rated as painful areas, with significantly higher frequency in JHS/EDS-HT than controls (90% vs 27%; 80.% vs 37%), for the neck and the shoulder, respectively.
Conclusions: Adults with JHS/EDS-HT have impaired shoulder function, increased pain intensity and more often generalized pain, as well as reduced physical HRQoL compared with the general population. Neck and shoulder joints were the most often painful areas in both groups, however, with significantly higher frequency in JHS/EDS-HT.
Jeppe Rasmussen, Stig Brorson, Ali Al-Hamdani, Bo S Olsen
Department of Orthopaedic Surgery, Herlev Hospital
Background: Resurfacing hemiarthroplasty (RHA) has a bone preserving design facilitating revision to other arthroplasty designs. For this reason, a high revision rate may be acceptable. However, the argument is only valid as long as the RHA can be revised to a satisfactory result.
Purpose / Aim of Study: The aim of this study was to report the outcome and the need for further surgery following revision of RHA in patients with osteoarthritis.
Materials and Methods: We reviewed all patients with osteoarthritis reported to the Danish Shoulder arthroplasty registry between 2006 and 2013. There were 1,210 RHA, of which 111 (9%) required revision. WOOS was accessed at 1 year and the need for re-revision were recorded.
Findings / Results: 40 RHA were revised to stemmed hemiarthroplasty, 30 to anatomical total shoulder arthroplasty and 31 to reverse total shoulder arthroplasty. Median WOOS scores for these 3 subpopulations were 48, range 5-97; 74, range 20-97; and 68, range 22-97 respectively. The median WOOS scores for primary stemmed hemiarthroplasty, total shoulder arthroplasty and reverse shoulder arthroplasty were 74, range 0- 100; 93, range 0-100; and 67, range 0- 100. The differences for stemmed hemiarthroplasty (P=0.003) and total shoulder arthroplasty (P=0.003) were statistically significant and the differences exceeded the minimal clinically important difference. 11 (10%) patients were re-revised mainly because of deep infection (n=6).
Conclusions: For a revision procedure, the outcome following revision of RHA is acceptable, but the results are inferior to that of primary stemmed hemiarthroplasty and primary anatomical total shoulder arthroplasty. The revision of RHA is associated with a high risk of infection. Thus, anatomical total shoulder arthroplasty remain our preferred choice in the treatment of osteoarthritis and RHA is reserve for selected cases only.
Department of Orthopaedic Surgery, Herlev Hospital
Background: Resurfacing hemiarthroplasty (RHA) has a bone preserving design facilitating revision to other arthroplasty designs. For this reason, a high revision rate may be acceptable. However, the argument is only valid as long as the RHA can be revised to a satisfactory result.
Purpose / Aim of Study: The aim of this study was to report the outcome and the need for further surgery following revision of RHA in patients with osteoarthritis.
Materials and Methods: We reviewed all patients with osteoarthritis reported to the Danish Shoulder arthroplasty registry between 2006 and 2013. There were 1,210 RHA, of which 111 (9%) required revision. WOOS was accessed at 1 year and the need for re-revision were recorded.
Findings / Results: 40 RHA were revised to stemmed hemiarthroplasty, 30 to anatomical total shoulder arthroplasty and 31 to reverse total shoulder arthroplasty. Median WOOS scores for these 3 subpopulations were 48, range 5-97; 74, range 20-97; and 68, range 22-97 respectively. The median WOOS scores for primary stemmed hemiarthroplasty, total shoulder arthroplasty and reverse shoulder arthroplasty were 74, range 0- 100; 93, range 0-100; and 67, range 0- 100. The differences for stemmed hemiarthroplasty (P=0.003) and total shoulder arthroplasty (P=0.003) were statistically significant and the differences exceeded the minimal clinically important difference. 11 (10%) patients were re-revised mainly because of deep infection (n=6).
Conclusions: For a revision procedure, the outcome following revision of RHA is acceptable, but the results are inferior to that of primary stemmed hemiarthroplasty and primary anatomical total shoulder arthroplasty. The revision of RHA is associated with a high risk of infection. Thus, anatomical total shoulder arthroplasty remain our preferred choice in the treatment of osteoarthritis and RHA is reserve for selected cases only.
Jeppe Rasmussen, Steen Lund Jensen, Stig Brorson
Department of Orthopaedic Surgery, Herlev Hospital
Background: The Nordic Arthroplasty Register Association (NARA) was initiated in 2007 by hip and knee surgeons and several unique papers have been published.
Purpose / Aim of Study: We aimed to examine the feasibility of merging data from the Nordic national shoulder arthroplasty registries by defining a common minimal data set. Furthermore, we used data from the dataset to report the incidence of shoulder replacement; and finally, we compared data from the individual registries.
Materials and Methods: In 2014, a group of surgeons met to examine the feasibility of merging data from the national shoulder registries in Denmark, Norway and Sweden. Differences in definitions and variables were discussed. A common minimal dataset was defined as a set of variables containing only data that all registries could deliver and where consensus according to definition of the variables could be made.
Findings / Results: We agreed upon a dataset containing patient-related data including diagnosis, operative data including implant design and data in case of revision including reason and new implant. 19857 primary arthroplasties were reported from 2004- 13. The number of replacements increased in the study period. With 13 replacements/100,000/year the incidence of shoulder replacement in Denmark was nearly twice the incidence in Norway. In Sweden, 50% of the implants used for osteoarthritis were total shoulder arthroplasties whereas in Denmark, 56% were resurfacing hemiarthroplasties and only 16% total shoulder arthroplasties. In Norway, 17% with a fracture were replaced with reverse shoulder arthroplasty compared to 4% in Denmark.
Conclusions: We were able to merge data from the national registries into one common dataset; however, the set of details was reduced. In future studies we will compare arthroplasty designs regarding revision rates and reasons for revision.
Department of Orthopaedic Surgery, Herlev Hospital
Background: The Nordic Arthroplasty Register Association (NARA) was initiated in 2007 by hip and knee surgeons and several unique papers have been published.
Purpose / Aim of Study: We aimed to examine the feasibility of merging data from the Nordic national shoulder arthroplasty registries by defining a common minimal data set. Furthermore, we used data from the dataset to report the incidence of shoulder replacement; and finally, we compared data from the individual registries.
Materials and Methods: In 2014, a group of surgeons met to examine the feasibility of merging data from the national shoulder registries in Denmark, Norway and Sweden. Differences in definitions and variables were discussed. A common minimal dataset was defined as a set of variables containing only data that all registries could deliver and where consensus according to definition of the variables could be made.
Findings / Results: We agreed upon a dataset containing patient-related data including diagnosis, operative data including implant design and data in case of revision including reason and new implant. 19857 primary arthroplasties were reported from 2004- 13. The number of replacements increased in the study period. With 13 replacements/100,000/year the incidence of shoulder replacement in Denmark was nearly twice the incidence in Norway. In Sweden, 50% of the implants used for osteoarthritis were total shoulder arthroplasties whereas in Denmark, 56% were resurfacing hemiarthroplasties and only 16% total shoulder arthroplasties. In Norway, 17% with a fracture were replaced with reverse shoulder arthroplasty compared to 4% in Denmark.
Conclusions: We were able to merge data from the national registries into one common dataset; however, the set of details was reduced. In future studies we will compare arthroplasty designs regarding revision rates and reasons for revision.
Lone Dragnes Brix, Theis Muncholm Thiellemann, Karen Toftdahl Bjørnholdt, Lone Nikolajsen
Department of Anaesthesiology, Horsens Regional Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital; Department of Ortopaedic , Horsens Regional Hospital
Background: Outpatient shoulder surgery has grown considerably over the past two decades. Good pain management after outpatient surgery is essential to make a short recovery time, early discharge and rapid return to daily living. Unfortunately, several studies have shown that pain is one of the most common complications of outpatient surgery. Severe pain remains a major problem and can lead to unscheduled contacts to healthcare professionals after discharge.
Purpose / Aim of Study: To assess the frequencies and causes of unscheduled contacts with healthcare professionals after outpatient shoulder arthroscopy within the first week after surgery with special emphasis on pain.
Materials and Methods: Outpatients scheduled for elective shoulder arthroscopy including subacromial decompression and acromioclavicular joint resection were enrolled at the Day Surgery Unit at Horsens Regional Hospital. One week after surgery patients received an electronic questionnaire containing questions about the post-discharge period.
Findings / Results: A total of 135 consecutive patients were enrolled. After discharge, 24.4 % of patients contacted healthcare professionals, 10 % had more than one unscheduled contact. Pain and prescription of pain medication were the leading causes for contact. Most contacts were made the day after surgery by telephone to the general practitioner. Even though 94 % of all patients reported to have received sufficient information and guidance regarding pain and pain-treatment after discharge, the most frequent result of contact was information and guidance combined with prescription of pain medication.
Conclusions: Unscheduled contacts to healthcare professionals after outpatient shoulder arthroscopy are a problem. Expected future findings in present study: Unscheduled contacts after outpatient surgery differ according to surgical procedures.
Department of Anaesthesiology, Horsens Regional Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital; Department of Ortopaedic , Horsens Regional Hospital
Background: Outpatient shoulder surgery has grown considerably over the past two decades. Good pain management after outpatient surgery is essential to make a short recovery time, early discharge and rapid return to daily living. Unfortunately, several studies have shown that pain is one of the most common complications of outpatient surgery. Severe pain remains a major problem and can lead to unscheduled contacts to healthcare professionals after discharge.
Purpose / Aim of Study: To assess the frequencies and causes of unscheduled contacts with healthcare professionals after outpatient shoulder arthroscopy within the first week after surgery with special emphasis on pain.
Materials and Methods: Outpatients scheduled for elective shoulder arthroscopy including subacromial decompression and acromioclavicular joint resection were enrolled at the Day Surgery Unit at Horsens Regional Hospital. One week after surgery patients received an electronic questionnaire containing questions about the post-discharge period.
Findings / Results: A total of 135 consecutive patients were enrolled. After discharge, 24.4 % of patients contacted healthcare professionals, 10 % had more than one unscheduled contact. Pain and prescription of pain medication were the leading causes for contact. Most contacts were made the day after surgery by telephone to the general practitioner. Even though 94 % of all patients reported to have received sufficient information and guidance regarding pain and pain-treatment after discharge, the most frequent result of contact was information and guidance combined with prescription of pain medication.
Conclusions: Unscheduled contacts to healthcare professionals after outpatient shoulder arthroscopy are a problem. Expected future findings in present study: Unscheduled contacts after outpatient surgery differ according to surgical procedures.
Marc Randall Kristensen, Jeppe Vejlgaard Rasmussen, Bo Sanderhoff Olsen, Stig Brorson
Department of Orthopaedic Surgery, Herlev Hospital
Background: Some patients with a failed osteosynthesis of a proximal humerus fracture are re- operated by joint replacement, but it has not been reported if previous osteosynthesis is a significant risk factor for inferior outcome after shoulder replacement.
Purpose / Aim of Study: To study if previous osteosynthesis is a risk factor for inferior outcome following shoulder replacement.
Materials and Methods: A matched case-control study based on data from the Danish Shoulder Arthroplasty Registry (DSR). All patients with shoulder arthroplasty after failed osteosynthesis of a proximal humerus fracture reported to DSR from 2006-13 were reviewed. Each case was matched with two controls based on age, gender and completeness of Western Ontario Osteoarthritis of the Shoulder index (WOOS). The controls had a primary shoulder replacement of a proximal humerus fracture. We compared WOOS and the relative risk of revision.
Findings / Results: 293 shoulder arthroplasties after failed osteosynthesis and 586 controls were included. Mean WOOS of the cases was 45.7 and of the controls 52.2. The difference of 6.5 points (95% CI 2.1-10.8; p=0.004) in favor of primary arthroplasty was statistically significant. 10.6% of the cases and 6.0% of the controls were revised, making the relative risk of revision 1.8 (95% CI 1.1-2.9; p=0.023).
Conclusions: WOOS was statistically significantly inferior in patients with shoulder replacement after failed osteosynthesis, but the difference may not be clinically relevant. However, we also found a significantly higher revision rate in patients with shoulder arthroplasty after failed osteosynthesis. Osteosynthesis should not be used as primary surgical treatment of proximal humerus fractures to delay shoulder replacement, and we advocate that peroperative conversion from osteosynthesis to shoulder arthroplasty is possible.
Department of Orthopaedic Surgery, Herlev Hospital
Background: Some patients with a failed osteosynthesis of a proximal humerus fracture are re- operated by joint replacement, but it has not been reported if previous osteosynthesis is a significant risk factor for inferior outcome after shoulder replacement.
Purpose / Aim of Study: To study if previous osteosynthesis is a risk factor for inferior outcome following shoulder replacement.
Materials and Methods: A matched case-control study based on data from the Danish Shoulder Arthroplasty Registry (DSR). All patients with shoulder arthroplasty after failed osteosynthesis of a proximal humerus fracture reported to DSR from 2006-13 were reviewed. Each case was matched with two controls based on age, gender and completeness of Western Ontario Osteoarthritis of the Shoulder index (WOOS). The controls had a primary shoulder replacement of a proximal humerus fracture. We compared WOOS and the relative risk of revision.
Findings / Results: 293 shoulder arthroplasties after failed osteosynthesis and 586 controls were included. Mean WOOS of the cases was 45.7 and of the controls 52.2. The difference of 6.5 points (95% CI 2.1-10.8; p=0.004) in favor of primary arthroplasty was statistically significant. 10.6% of the cases and 6.0% of the controls were revised, making the relative risk of revision 1.8 (95% CI 1.1-2.9; p=0.023).
Conclusions: WOOS was statistically significantly inferior in patients with shoulder replacement after failed osteosynthesis, but the difference may not be clinically relevant. However, we also found a significantly higher revision rate in patients with shoulder arthroplasty after failed osteosynthesis. Osteosynthesis should not be used as primary surgical treatment of proximal humerus fractures to delay shoulder replacement, and we advocate that peroperative conversion from osteosynthesis to shoulder arthroplasty is possible.
Sahar Moeini, Stig Brorson, Tobias Wirenfeldt Klausen, Jeppe V. Rasmussen
Department of Orthopedic Surgery, Herlev Hospital; Department of Hematology, Herlev Hospital
Background: The Western Ontario Osteoarthritis of the Shoulder (WOOS) index is a disease-specific patient-reported 19-question survey that measures quality of life among osteoarthritis (OA) patients. WOOS is used for the evaluation of shoulder arthroplasty in patients reported to the Danish Shoulder Arthroplasty Register (DSR).
Purpose / Aim of Study: The purpose of this study was to validate the Danish version of WOOS for OA patients and secondly for other diagnoses through modern test theory.
Materials and Methods: The study included 2416 arthroplasties in 2298 patients reported to DSR between 2006 and 2011. Five diagnoses were included: 100 rheumatoid arthritis; 847 osteoarthritis; 161 rotator cuff arthropathy; 1140 fracture; and 168 revisions. We tested the fit of different diagnoses to the Rasch model. The dimensionality of WOOS was further examined with residual Principal Component Analysis (PCA). WOOS was regarded as dichotomous in the study.
Findings / Results: A dichotomous scale was the best fit for WOOS. The analysis of the OA patients had a good reliability and showed adequate targeting and a good fit to the model. The analysis of fracture (FR) patients showed an even better fit and higher reliability. The WOOS items fitted well to the OA sample except from two items, item 5 and 6. In addition, item 6 showed signs of degrading the scale. Only item 6 showed misfit for FR patients and there was no sign of scale degradation. The residual PCA confirmed unidimensionality for FR patients but not for OA patients. Six items displayed clinically significant Differential Item Functioning between OA and FR patients.
Conclusions: The Rasch analysis generally suggested that WOOS can be considered valid and representative for quality of life level of both OA and FR patients. Surprisingly, FR had the best fit to WOOS even though WOOS is originally made for OA.
Department of Orthopedic Surgery, Herlev Hospital; Department of Hematology, Herlev Hospital
Background: The Western Ontario Osteoarthritis of the Shoulder (WOOS) index is a disease-specific patient-reported 19-question survey that measures quality of life among osteoarthritis (OA) patients. WOOS is used for the evaluation of shoulder arthroplasty in patients reported to the Danish Shoulder Arthroplasty Register (DSR).
Purpose / Aim of Study: The purpose of this study was to validate the Danish version of WOOS for OA patients and secondly for other diagnoses through modern test theory.
Materials and Methods: The study included 2416 arthroplasties in 2298 patients reported to DSR between 2006 and 2011. Five diagnoses were included: 100 rheumatoid arthritis; 847 osteoarthritis; 161 rotator cuff arthropathy; 1140 fracture; and 168 revisions. We tested the fit of different diagnoses to the Rasch model. The dimensionality of WOOS was further examined with residual Principal Component Analysis (PCA). WOOS was regarded as dichotomous in the study.
Findings / Results: A dichotomous scale was the best fit for WOOS. The analysis of the OA patients had a good reliability and showed adequate targeting and a good fit to the model. The analysis of fracture (FR) patients showed an even better fit and higher reliability. The WOOS items fitted well to the OA sample except from two items, item 5 and 6. In addition, item 6 showed signs of degrading the scale. Only item 6 showed misfit for FR patients and there was no sign of scale degradation. The residual PCA confirmed unidimensionality for FR patients but not for OA patients. Six items displayed clinically significant Differential Item Functioning between OA and FR patients.
Conclusions: The Rasch analysis generally suggested that WOOS can be considered valid and representative for quality of life level of both OA and FR patients. Surprisingly, FR had the best fit to WOOS even though WOOS is originally made for OA.