Less encouraging results have been reported in FS patients (Boileau et al. 2001
, Haines et al. 2006
). In our study, OSS improved in FS patients, but to a lesser degree than for patients with OA and RA, and the end results were somewhat inferior to those for OA and RA. However, as shoulders with fracture sequelae are very often badly damaged both with respect to the shoulder joint and the rotator cuff, the results in these patients may be considered satisfactory. We have previously shown that FS patients have the worst outcome in terms of implant survival (Fevang et al. 2009
). On the other hand, patients with AFs had OSS end results that were as good as those for RA patients and they have been shown to have the lowest risk of revision (Fevang et al. 2009
Interestingly, the improvement in function was almost as good as for pain, while the indication for surgery is most often pain. The improved function may be due to less pain, but even so, the finding of good functional results should be considered when evaluating the indication for shoulder arthroplasty.
To gain a better understanding of the OSS results, the scores were dichotomized according to a cut-off value (PASS) obtained from a recent study (Christie et al. 2011
). Using this cut-off value, 40–50% of our patients were defined to be in PASS in 2010 (at the time of filling in the questionnaires). This was a vast improvement for RA and OA patients in particular (i.e. from 5% to 50% for OA patients), but also for FS patients. A higher percentage of patients in PASS might have been found if the patients had been assessed earlier (i.e. at 1 year postoperatively) and if patients with revisions had been excluded. Even so, the rather large group that did not achieve PASS indicates that although a substantial improvement is obtained, the end-result may still not be completely satisfactory.
Impairment in the general health status, as measured by the preoperative EQ-5D, was seen in patients with a preoperative shoulder disease (OA, RA, or FS). It has been shown that general health perception scores decrease steadily after the age of 50 (Boorman et al. 2003
). Even so, patients with acute fractures who were older than the other patients reported markedly better scores on preoperative EQ-5D than those in the other 3 groups. This shows that the shoulder arthropathy causing the shoulder operation had substantial effects on several aspects of life quality. This was further illustrated by the finding of a substantial improvement in EQ-5D after surgery. Similar findings have been described in patients with shoulder osteoarthritis (Lo et al. 2005
), and Boorman et al. (2003)
described similar improvement in health status for shoulder arthroplasty as for hip arthroplasty. A recent study showed comparable improvements in EQ-5D after hip arthroplasty and knee arthroplasty (0.31 and 0.22, respectively) to what we found after shoulder arthroplasty (Jansson and Granath 2011
The improvement in EQ-5D was markedly lower for the FS group, and this probably reflects the higher preoperative score in this group. RA is a systemic disease that affects general health status, but why the OA patients had a lower preoperative life quality than FS patients is less obvious. Some OA patients may have impaired quality of life because of polyarticular disease, and others because of comorbidity associated with a high BMI—which is a risk factor for osteoarthritis. With a better preoperative status in the FS group, superior end results would be expected in this group. That this is not the case strengthens the impression of less favorable results after shoulder arthroplasty for this indication.
Another important finding was that total prostheses had better results than hemiprostheses in terms of pain and function (OSS). Similar findings were reported in 2 review articles comparing hemiprostheses and total prostheses (Bryant et al. 2005
, Radnay et al. 2007
). Our results support the increasing use of total prostheses currently taking place in Norway. The major interest of our study was not prosthesis type. A detailed analysis of pain and function according to prosthesis type will be part of our next study.
Strengths and weaknesses
A weakness of our study was the response rate of 65%. The non-responders differed from the responders in that there were more women who were older, and they more often had AFs. Although we cannot know whether the results in the non-responder group would have differed from those of the responders, the similar revision rates in the groups suggest that there were no large differences in results between the responders and the non-responders. Even so, the proportion of hemiprostheses in the non-responder group was higher and the indication for revision may be different for hemiprostheses than for total prostheses. Thus, a similar revision rate may not fully ensure a lack of difference in results between non-responders and responders. The retrospective collection of preoperative scores was another weakness of our study. However, it has been shown that in larger groups of people, there is no statistically significant nor clinically relevant difference between a recollected OSS score and a contemporary score—although it was found that there was a slight tendency to overestimate the symptoms when remembering them (Wilson et al. 2009
). We believe that the consistency of our results confirms this, as shown, for example, by the similarity of preoperative scores for RA and OA patients and by the correlation of EQ-5D and OSS results (i.e. with RA scoring being worst for all preoperative parameters; ).
A major strength of our study was the very large study population, which allowed comparison of different diagnostic groups and adjustment for possible confounders. To our knowledge, there have been no studies assessing function, pain, and quality of life after shoulder replacement in such a large study population. Also, our study was based on national registry data—which means that the study population was from a real-life setting. Thus, we contacted and included patients who had been operated at all types of hospitals, and there was a large spectrum of implants.
Good results in terms of improved pain, function, and quality of life were observed after shoulder arthroplasty for patients with RA, OA, and FS—although somewhat inferior results were seen in the group with sequelae. AF patients had as good end results as the other diagnostic groups. Shoulder function improved almost as much as pain. A shoulder arthropathy has a major effect on life quality, and treatment with shoulder replacement not only improves shoulder function and reduces pain in the shoulder, but it also significantly improves quality of life.