[ research report ] ANDREW M. MCMILLAN, PhD1,2 • KARL B. LANDORF, PhD1,2 • JULIE M. GREGG, PhD3 JASON DE LUCA, DMU3 • MATTHEW P. COTCHETT, BPod(Hons)1,2 • HYLTON B. MENZ, PhD1,2 Hyperemia in Plantar Fasciitis Determined by Power Doppler Ultrasound lantar fasciitis is characterized by chronic inferior heel pain and terioration of collagen fibers, increased point tenderness at the calcaneal origin of the plantar fascia. secretion of ground-substance proteins, The condition is exacerbated by weight bearing after periods focal areas of fibroblast proliferation, and increased vascularity.10,22 These find- of rest and typically resolves after 12 months with conservative ings are similar to those reported in the P 5 management. The prevalence of heel pain in the general population tendinopathy literature,11 in which neuro- is estimated to range from 3.6% to 7%,7,9 and plantar fasciitis has vascular in-growth has been suggested to be a likely pain mechanism.1 been shown to account for 10% of mus- gated. However, a range of tissue changes Within human musculoskeletal tis- culoskeletal conditions affecting the foot at the subcalcaneal enthesis have been sues, the close anatomical relationship and ankle.19 demonstrated in patients undergoing between blood vessels and nerves is well The underlying pathology of plantar surgery for longstanding symptoms. The known, and, as a consequence, nerves fasciitis has not been thoroughly investi- most commonly reported features are de- are often described as “accompanying” or “traveling with” their respective blood vessels.2 Accordingly, it is likely that STUDY DESIGN: Cross-sectional observational RESULTS: Hyperemia of the plantar fascia was TT TT neovascularization of connective tissue study. present in 8 of 30 participants with plantar fasciitis in disorders such as plantar fasciitis and OBJECTIVES: To investigate the presence and in 2 of 30 controls. The between-group dif- TT tendinopathy also involves concurrent of soft tissue hyperemia in plantar fasciitis with ference for hyperemia, using a 4-point scale, was power Doppler ultrasound. statistically significant, with participants with plan- in-growth of nerve fibers, thereby in- tar fasciitis showing increased Doppler ultrasound creasing sensitivity to pain mediators at BACKGROUND: Localized hyperemia is an es- TT signal compared to controls (Mann-Whitney U, P the site of injury. In relation to plantar tablished feature of tendinopathy, suggesting that = .03). However, the majority of participants with fasciitis, although several histological neurovascular in-growth may contribute to tendon- plantar fasciitis with evidence of hyperemia dem- 10,13,14,22 associated pain in some patients. The presence of onstrated very mild color changes, and only 3 were studies have reported evidence abnormal soft tissue vascularity can be assessed found to have moderate or marked hyperemia. of angiogenesis within the plantar fas- with Doppler ultrasound, and a positive finding can cia enthesis, these studies did not utilize assist with targeted treatment plans. However, very CONCLUSION: Mild hyperemia can occur with TT techniques that enabled identification of little is known regarding the presence of hyperemia plantar fasciitis, but most individuals will not ex- in plantar fasciitis and the ability of routine Dop- hibit greater soft tissue vascularity when assessed nerve fibers and, therefore, did not dem- pler ultrasound to identify vascular in-growth in the with routine Doppler ultrasound. Clinicians treating onstrate neural in-growth as a feature of plantar fascia near its proximal insertion. plantar fasciitis should not consider a positive the condition. However, concurrent in- Journal of Orthopaedic & Sports Physical Therapy® Downloaded from www.jospt.org at on August 1, 2014. For personal use only. No other uses without permission. Copyright © 2013 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved. Doppler signal as essential for diagnosis of the METHODS: This observational study included growth of neural and vascular structures TT condition but, rather, as a feature that may help to 30 participants with plantar fasciitis unrelated to has been shown to occur with Achil- refine the treatment plan for an individual patient. systemic disease and 30 age- and sex-matched les tendinopathy,2,4 J Orthop Sports Phys Ther 2013;43(12):875-880. and, considering controls. Ultrasound examination was performed Epub 11 October 2013. doi:10.2519/jospt.2013.4810 the fundamental relationship between with a 13- to 5-MHz linear transducer, and power tendon and the plantar fascia (both are Doppler images were assessed by 2 blinded TTKEY WORDS: heel pain, imaging, investigators. neovascularization dense, regular connective tissue), it is likely that accompanying nerve fibers are 1Department of Podiatry, Faculty of Health Sciences, La Trobe University, Melbourne, Victoria, Australia. 2Musculoskeletal Research Centre, Faculty of Health Sciences, La Trobe University, Melbourne, Victoria, Australia. 3Southern Cross Medical Imaging, La Trobe University Private Hospital, Bundoora, Victoria, Australia. This project was funded by the Musculoskeletal Research Centre, La Trobe University, Australia. The authors certify that they have no affiliations with or financial involvement in any organization or entity with a direct financial interest in the subject matter or materials discussed in the article. Address correspondence to Dr Andrew McMillan, La Trobe University, Kingsbury Drive, Melbourne, Victoria 3108 Australia. E-mail: [email protected] Copyright ©2013 Journal of Orthopaedic & Sports Physical Therapy® T journal of orthopaedic & sports physical therapy | volume 43 | number 12 | december 2013 | 875 43-12 McMillan.indd 875 11/18/2013 3:20:01 PM [ research report ] tar fasciitis related to spondyloarthritis reported no evidence of hyperemia in those with plantar fasciitis compared to 24 controls, indicating the need for ad- ditional research in this area. Therefore, the aim of this study was to investigate whether soft tissue hyper- emia is present in plantar fasciitis, using conventional ultrasound techniques. A secondary objective was to investigate changes in plantar fascia thickness, with emphasis on clinically useful diagnostic threshold values. METHODS FIGURE 1. A longitudinal sonogram of the plantar fascia at the calcaneal origin. thical approval for the study also present with neovascularization in In so doing, PDU is not affected by flow- protocol was granted by the La Trobe plantar fasciitis. direction artifacts (eg, aliasing), allowing EUniversity Human Ethics Commit- Doppler ultrasonography involves the a lower pulse-repetition frequency to be tee, and all participants gave written processing of echoes produced by mov- used, which improves sensitivity to slow- informed consent prior to enrollment. ing objects within the scanning field (eg, moving blood within small vessels.12,15 Ultrasound imaging was conducted at blood flow within a vessel). The under- Therefore, PDU has an advantage when the La Trobe University Private Hospital pinning principle is that moving objects assessing musculoskeletal tissues for evi- (Bundoora, Australia) between January reflect the ultrasound pulse at a fre- dence of abnormal vascular perfusion. 2011 and February 2012. quency different from that of the origi- In relation to plantar fasciitis, 1 study23 Participants with plantar fasciitis were nal transmission (known as the Doppler has shown a relationship between inferi- recruited from the local community (by effect), and a frequency shift is thereby or heel pain and hyperemia of the plantar newspaper advertising) and from other detected when the echo is received by fascia, using PDU. In that study, moder- heel-pain projects that had recently the transducer.12 Furthermore, the direc- ate to marked hyperemia was observed in concluded at the university. These par- tion of movement toward or away from 8 of 20 participants with plantar fasciitis, ticipants were required to have a history the transducer is also determined by the compared to no hyperemia in 20 controls of inferior heel pain for at least 8 weeks, nature of the frequency shift, with either (P<.01). These results support the find- with a minimum average pain severity a higher frequency or lower frequency de- ings of histological studies of hyperemia (during the past week) of 20 mm on a tected, respectively.12 The resulting image in plantar fasciitis, and suggest that Dop- 100-mm visual analog scale. Plantar fas- produced demonstrates these frequency pler ultrasound assessment should be ciitis was confirmed by ultrasound assess- shifts by assigning colors to the corre- considered when imaging patients with ment and considered present when the sponding display pixels, coded according inferior heel pain. However, that study plantar fascia was 4.0 mm or greater at to the direction and velocity of movement was susceptible to bias due to method- the calcaneal origin.16 Exclusion criteria (ie, moving objects are represented by ological limitations. For example, the for case participants included corticoste- Journal of Orthopaedic & Sports Physical Therapy® Downloaded from www.jospt.org at on August 1, 2014. For personal use only. No other uses without permission. Copyright © 2013 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved. color images).12 PDU image assessor was not blinded, and roid injection of the heel within the past In addition to color Doppler, a varia- control participants