Oxford Shoulder Score (OSS)
The Oxford Shoulder Score (OSS) is a validated patient-reported outcome measure (PROM) whose use has seen an increase over the past few years. It’s a shoulder-specific instrument designed to assess the outcome of all shoulder surgeries (with the exception of instability surgery). It’s now used in a number of countries and has also been applied in cohort studies, audits, and national joint replacement registries .
The OSS questionnaire contains 12 items, each with five potential answers. Patients are asked to rate their symptoms between 1 (minimal symptoms) and 5 (severe symptoms). The combined total gives a minimum score of 12 and a maximum of 60. However, counter-intuitive to other tools, higher scores in the OSS imply worse functionality while lower scores imply better functionality.
At the time of its development, the OSS scoring system was designed to be as simple as possible in order to encourage its use . Scores from each question were added with lower scores corresponding to better outcomes. This scoring system is the exact opposite to its sister outcome measures – the Oxford Hip and Oxford Knee surveys, where higher scores corresponded to better outcomes. Subsequently, many surgeons using the Oxford Hip and Oxford Knee surveys found the scoring for the Oxford Shoulder un-intuitive and resorted to using different systems . In 2009 the authors of the OSS reversed the scoring methodology so that lower scores would represent worse outcomes, thus bringing it in line with similar tools.
Users of OSS should keep this in mind when reading medical research studies and make note if the study was conducted either pre-2009 or post-2009 when the scoring methodology was changed.
The OSS itself has undergone rigorous testing for validity, reliability, and sensitivity to change and has been shown to be a robust tool for assessing the outcome of shoulder surgery . It is also helpful for looking at the success of an intervention by comparing pre and post-operative scores .
One of the perceived advantages of using a joint-specific score like the OSS is that it allows it to be sensitive to the disability from the shoulder while being influenced as little as possible by other co-morbidities .
Additionally, the Oxford Shoulder Questionnaire has been shown to correlate well with both the Constant Score and the SF-36 assessment . It’s also been described as a valid measure of shoulder function in patients with rheumatic diseases who undergo shoulder surgery .
The main disadvantage of the Oxford Shoulder Score is that it doesn’t assess shoulder instability. This limits its effectiveness as an overall tool for assessment. Therefore, the significant number of pathologies that are associated with shoulder instability are automatically excluded from use with this tool. It is also the only condition-specific PRO tool designed to assess shoulder surgery intervention.
Permission to use the Oxford Shoulder Score can be acquired from Isis Innovation Ltd (the technology transfer company of the University of Oxford) via their website
- Younis, F., Sultan, J., Dix, S., & Hughes, P. (2011). The range of the Oxford Shoulder Score in the asymptomatic population: a marker for post-operative improvement. Annals of The Royal College of Surgeons of England, 93(8), 629–633. http://doi.org/10.1308/003588411X13165261994193 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3566690/
- Dawson, J., Rogers, K., Fitzpatrick, R., & Carr, A. (2009). The Oxford shoulder score revisited. Archives of orthopaedic and trauma surgery, 129(1), 119-123. https://pubmed.ncbi.nlm.nih.gov/18183410/
- Christie, A., Dagfinrud, H., Garratt, A. M., Osnes, H. R., & Hagen, K. B. (2011). Identification of shoulder-specific patient acceptable symptom state in patients with rheumatic diseases undergoing shoulder surgery. Journal of Hand Therapy, 24(1), 53-61. http://www.ncbi.nlm.nih.gov/pubmed/21272764