There have been many papers published recently on the results of the reversed shoulder prosthesis. This prosthesis was originally designed for the treatment of cuff tear arthropathy in the elderly from the original design of Grammont. The results for cuff arthropathy showed that by using the geometry of his design it was possible to regain elevation and abduction in the pseudo paralytic shoulder.
Previously these had been very difficult cases to treat with very disappointing results. Enormous enthusiasm was generated for this type of prosthesis. Hence the indications were widened to include many different types of difficult shoulder problems, often unwisely.
Many papers have now shown that the results of reversed prosthesis for indications other than primary cuff tear arthropathy are poor. One rarely sees a survivorship analysis. This current paper is of great interest because, on the results of the original series the team were enthusiastic and pleased, however with time the Constant score has been falling more than would be expected with age alone. Interestingly they point out that the radiological signs of failure can be correlated with the drop in Constant score. Previously this has been disputed in that “notching” is only a radiological sign and may not have clinical value. In the early years of hip replacement radiolucent lines around the acetabular component were initially said to be of no importance, then only of importance if they were progressive and then finally it became obvious that they were an early sign of failure. It seems strange that we have to re-learn this lesson with the shoulder.
All these papers concerning extended indications for the reverse prosthesis state that they must only be considered for the elderly and yet in this series the youngest patient was 58 years old. It must be noted that the life expectancy of a 75 year old is 12 years. We have no adequate mean figures to support doing it even in this age group.
This paper quite rightly points out that these fractures in the elderly are extremely difficult to treat and the results by other methods are also very poor, and therefore feel justified in trying something different as it may be better. With the torrent of recent publications this does not appear to be justified. 63% of worrying radiological changes before 7 years which are progressive in 40% should not really be an indication for surgery under circumstances where the revision procedure is salvage at best. This group also very honestly report diminution in function although far more space is given over to the radiological assessment than to the clinical assessment. As they state, in the main, these patients are elderly and may indeed have low expectation from their surgery; 90% of activities of daily living are carried out below shoulder height with cooking, personal hygiene and eating a priority. It appears that rotation at waist height cannot be improved by this prosthesis and in fact often it is lost and sometimes can change a patient who is independent prior to surgery into one who is care dependent. The fact that some patients can regain elevation above shoulder height is of little interest to the majority who really want useful functional pain free rotation below shoulder height.
This group must be applauded for coming back and reporting their series of worsening results and they must continue to follow them, hopefully with survival curves so that these may be compared with other procedures. In the meantime it seems we, as surgeons, tend to remember the good results and forget the poor. Just because some of our patients can regain good active elevation above shoulder height it is not what a lot of these elderly patients really require. When counselling a patient being considered for this type of procedure, the results of reverse prosthesis for primary cuff tear arthropathy should not be considered. The extended indications and results for fracture do not compare. One still has to consider what happens if it goes wrong and what is the revision procedure. There is enough published evidence now for both surgeons and patients to be much better informed and surgical enthusiasm tempered with realism.
Reading Shoulder Unit, Berkshire Independent Hospital, Reading, United Kingdom