P46 Swimmer’s thoracic outlet: it doesn’t have quite the same ring as tennis elbow

Abstract Background We present a case that was referred and seen in our chronic pain clinic, and highlight the importance of keeping an open mind about alternative diagnoses when reviewing these patients. Methods Please refer to the results section. Results A 12 year-old girl was referred with right sided neck and shoulder pain associated with occasional pins and needles. The patient was a competitive swimmer, training and competing five times a week at her peak. She did not have a history of mottling or colour change, and clinically she had full range of motion of her joints and no neurological deficit. On repeated assessments, she had reproducible pain on horizontal flexion and reduced muscle bulk of the right shoulder, although power was preserved. Functionally the patient had to reduce her participation in swimming due to pain, and found it difficult to carry or lift things, brush or wash her hair, or write for extended periods of time. Imaging with shoulder X-ray and shoulder and cervical spine MRI did not reveal a cause, and she did not have an anatomical variation such as a thoracic rib. Due to the reproducibility on swimming, an ultrasound looking at the insertion of the biceps insertion during dynamic movements was arranged and was also normal with no subluxation noted. As she failed to improve with chronic pain education, chronic pain approach to physiotherapy sessions and graded reintroduction of swimming, ultrasound angiology was arranged. This showed minor disease in the right subclavian, axillary, brachial, radial and ulnar arteries, with significant reduction in right brachial arterial flow with the patient supine, right arm in horizontal flexion and contralateral head turn. This suggested arterial thoracic outlet syndrome (TOS). All other positions resulted in no significant difference in arterial flow. TOS is traditionally broken into two categories – neurogenic and vascular, the latter can be broken down further into arterial or venous. While in adults, the vast majority (90-95%) present as neurogenic, in the paediatric population there is a higher proportion of vascular cases. This has implications, as vascular TOS can be complicated by vessel disease and thrombus formation. There are a number of case reports in which management is reported as decompression of the thoracic outlet with partial first rib resection, with or without scalene muscle resection. Consideration of hypercoagulable states is also warranted. We have referred our pati