Studies in shoulder disorders and tendinopathy

The human shoulder is the most complex of any peripheral synovial joint. Despite the high incidence and prevalence of symptomatic shoulder disorders, particularly of the rotator cuff, a paucity of robust research exists into this area. Lack of consensus on the most appropriate clinical method of assessing the shoulder and lack of adequate diagnostic criteria has inhibited the development of effective management strategies. This has substantial implications for individuals, health systems and society. Improvement in the evidence-base for appropriate classification and treatment of shoulder disease is therefore required. The aim of my research was to address limitations in the knowledge base in this context as a first step to optimising outcomes for individuals suffering from shoulder pain. In relation to the epidemiology I undertook a prospective observational study in two large general practices to determine the spectrum of shoulder pathology presenting to primary care and the impact shoulder disorders have on the individual. Shoulder pain was most commonly due to rotator cuff tendinopathy (85%) and this was associated with significantly reduced health outcomes. The results have highlighted the burden of shoulder disease and will inform where best to direct therapeutic interventions. Due to limited healthcare resources I then evaluated whether non-shoulder specialists could undertake an appropriate initial assessment of the shoulder joint and found that they could reliably assess the rotator cuff and other common shoulder diseases following a short, structured training period by a rheumatology specialist. The results have implications for delegation of shoulder assessment to community settings, to the development of a simplified evaluation schedule, and to improve uniformity in epidemiological research and inclusion criteria for intervention studies. Although commonly used in practice and research the validity of clinical examination tests for shoulder disease have not been adequately determined. I investigated this using MRI changes and arthroscopic diagnosis as the gold standard and found that the sensitivity of clinical examination for any cuff pathology was high however its specificity was low. This work highlighted the significant limitations of examination alone and that judicious use of imaging is necessary to inform management decisions. As the optimal management of shoulder disease, specifically tendinopathy of the rotator cuff, remains unclear further therapeutic options are required. I therefore evaluated whether a novel intervention (low intensity ultra-sound) would be an appropriate for the treatment of tendinopathies. In a randomised controlled trial using lateral epicondylitis (a prototype tendinopathy), as a surrogate for rotator cuff tendinopathy, low intensity ultrasound was ineffective for a large treatment effect and thus further assessment of its usefulness was not pursued