Background/hypothesis: Shoulder pain in elite swimmers is common, and its pathogenesis is uncertain. Hypothesis/study design: The authors used a crosssectional study design to test Jobe's hypothesis that repetitive forceful swimming leads to shoulder laxity, which in turn leads to impingement pain. Methods: Eighty young elite swimmers (13-25 years of age) completed questionnaires on their swimming training, pain and shoulder function. They were given a standardised clinical shoulder examination, and tested for glenohumeral joint laxity using a non-invasive electronic laxometer. 52/80 swimmers also attended for shoulder MRI. Results: 73/80 (91%) swimmers reported shoulder pain. Most (84%) had a positive impingement sign, and 69% of those examined with MRI had supraspinatus tendinopathy. The impingement sign and MRIdetermined supraspinatus tendinopathy correlated strongly (r s =0.49, p<0.00001). Increased tendon thickness correlated with supraspinatus tendinopathy (r s =0.37, p<0.01). Laxity correlated weakly with impingement pain (r s =0.23, p<0.05) and was not associated with supraspinatus tendinopathy (r s =0.14, p=0.32). The number of hours swum/week (r s =0.39, p<0.005) and weekly mileage (r s =0.34, p=0.01) both correlated signifi cantly with supraspinatus tendinopathy. Swimming stroke preference did not. Conclusions: These data indicate: (1) supraspinatus tendinopathy is the major cause of shoulder pain in elite swimmers; (2) this tendinopathy is induced by large amounts of swimming training; and (3) shoulder laxity per se has only a minimal association with shoulder impingement in elite swimmers. These fi ndings are consistent with animal and tissue culture fi ndings which support an alternate hypothesis: the intensity and duration of load to tendon fi bres and cells cause tendinopathy, impingement and shoulder pain.

BackgroundAdipose tissue is an attractive source of cells for therapeutic purposes because of the ease of harvest and the high frequency of mesenchymal stem cells (MSCs). Whilst it is clear that MSCs have significant therapeutic potential via their ability to secrete immuno-modulatory and trophic cytokines, the therapeutic use of mixed cell populations from the adipose stromal vascular fraction (SVF) is becoming increasingly common.MethodsIn this study we have measured a panel of 27 cytokines and growth factors secreted by various combinations of human adipose-derived cell populations. These were 1. co-culture of freshly isolated SVF with adipocytes, 2. freshly isolated SVF cultured alone, 3. freshly isolated adipocytes alone and 4. adherent adipose-derived mesenchymal stem cells (ADSCs) at passage 2. In addition, we produced an ‘in silico’ dataset by combining the individual secretion profiles obtained from culturing the SVF with that of the adipocytes. This was compared to the secretion profile of co-cultured SVF and adipocytes. Two-tailed t-tests were performed on the secretion profiles obtained from the SVF, adipocytes, ADSCs and the ‘in silico’ dataset and compared to the secretion profiles obtained from the co-culture of the SVF with adipocytes. A p-value of < 0.05 was considered statistically different. To assess the overall changes that may occur as a result of co-culture we compared the proteomes of SVF and SVF co-cultured with adipocytes using iTRAQ quantitative mass spectrometry.ResultsA co-culture of SVF and adipocytes results in a distinct secretion profile when compared to all other adipose-derived cell populations studied. This illustrates that cellular crosstalk during co-culture of the SVF with adipocytes modulates the production of cytokines by one or more cell types. No biologically relevant differences were detected in the proteomes of SVF cultured alone or co-cultured with adipocytes.ConclusionsThe use of mixed adipose cell populations does not appear to induce cellular stress and results in enhanced secretion profiles. Given the importance of secreted cytokines in cell therapy, the use of a mixed cell population such as the SVF with adipocytes may be considered as an alternative to MSCs or fresh SVF alone.

Rugby league players have a lower prevalence of depression compared with studies of the general population and other athletes, but a higher prevalence of GAD, and high rates of alcohol misuse. Clubs may consider implementing regular screening for these conditions. Further prospective research to determine causality of independent factors is required.

Objective: To determine the interobserver and intraobserver reliability of the interpretation of MRIs for supraspinatus tendinosis. Methods: In the interobserver trial, the MRIs of 52 athletes' shoulders were observed by 3 observers on one occasion within a 2-month period. All 52 images were read by the most experienced musculoskeletal radiologist on 3 different occasions on separate days without access to the previous readings for the intraobserver trial. Supraspinatus tendinosis was graded using a modified 4-point scale from grades 0 to grade 3. Results: The grading of MRI-determined supraspinatus tendinosis was reliable, having an intraclass correlation (ICC) of 0.85 when assessed by the single well-trained observer. Interobserver reliability was only fair to good (ICC = 0.55). Conclusions: Supraspinatus tendinosis can be accurately identified on MRI with little variation by a single well-trained observer. Interobserver reliability was only fair to good. Our data indicated that the reliability of the assessment was much greater in more experienced radiologists than in those with less experience. M RI has proven to be useful in the assessment of rotator cuff injuries. MRI is a non-invasive method of imaging and is unique in that it allows the differentiation of soft tissue structures.1 Improvements in MRI techniques, including fast spin-echo imaging and fat saturation, have facilitated demonstration of tendinous abnormalities of the rotator cuff.The MRI findings of rotator cuff tendinopathy are characterised by thickened inhomogeneous rotator cuff tendon with increased signal intensity on all pulse sequences. 2 Fluid intensity filling an incomplete gap in the tendon on fatsuppressed T2-weighted sequences changes are seen on MRI for partial-thickness tears.3 On MRI, an area of high signal intensity on all pulse sequences outlines complete disruption of the tendon.

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