Ultrasonography and image-guided corticosteroid injection for plantar fasciitis

Submission note: A thesis submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy to the Department of Podiatry, School of Allied Health, Faculty of Health Sciences, La Trobe University, Bundoora.

Background: Plantar fasciitis is a common musculoskeletal condition that causes persistent pain under the heel. The disorder can affect a range of people from various age groups, and typically occurs without involvement of underlying systemic disease. The symptoms of plantar fasciitis can vary from a mild transitory irritation to a constant disabling pain, and people with the condition often experience a negative impact on their health-related quality of life. By reviewing the current literature and undertaking original investigations, this thesis will explore the diagnostic features of plantar fasciitis with an emphasis on ultrasonography, and determine the value of image-guided corticosteroid injection for treatment of the condition. Methodology: Three main projects were conducted for this thesis. Firstly, a systematic review was undertaken to establish the underlying tissue changes associated with heel pain, by drawing together evidence from a variety of diagnostic imaging studies. Secondly, a randomised controlled trial was carried out to investigate the effectiveness of corticosteroid injection for treatment of plantar fasciitis. This study incorporated an image-guided injection technique for delivery of the drug into the affected tissue. The third study further utilised ultrasonography to observe the imaging features of plantar fasciitis, with emphasis on vascular in-growth into the plantar fascia and the possible pain mechanisms involved with the condition. Findings: The findings of this thesis demonstrate that swelling and degeneration of the plantar fascia are common imaging features associated with heel pain. Ultrasound-guided injection with a highly soluble corticosteroid was shown to significantly reduce pain in the short-term, and the injection also reduced swelling of the plantar fascia over a three month period. These findings are important for clinical practice as they indicate that an image-guided corticosteroid injection is a safe and effective treatment for plantar fasciitis, and that such an injection leads to sustained physiological changes within the affected tissue. The final study presented in this thesis demonstrated that mild hyperaemia is associated with plantar fasciitis, but that markedly increased vascularity is not a feature of the condition.