Plantar heel pain: an update of its aetiology and diagnosis Karl B. Landorf, Andrew M. McMillan, Hylton B. Menz Department of Podiatry Lower Extremity and Gait Studies (LEGS) Research Program Please change font size as necessary.

Conflict of interest statement All authors declare that there are no known conflicts of interest related to this project.

Introduction

What is it? Pathology is not well understood1 Traditionally accepted that it is due to stress of the fascia, which leads to microtears and inflammation However, histopathology presents a different picture Degenerative process (no inflammation)2 Suggested the term ‘plantar fasciosis’ Limitation – long standing cases and only focused on the plantar fascia 1 Wearing et al, Sports Med, 2006 2 Lemont et al, JAPMA, 2003

Nomenclature Plantar heel pain (PHP) Plantar fasciitis (PF) Plantar fasciosis *Plantar fasciopathy

Imaging

Plain film x-rays

Plain film x-rays Heel spurs are common in plantar heel pain Correlation between spurs and plantar heel pain However, is it the cause of heel pain? Many have a spur but no pain 8-15% of asymptomatic population have spurs1 However, up to 65% of patients complaining of heel pain have signs of a plantar heel spur2 Spurs can fracture 1Shama & Kamansky, 1983 2Prichasuk et al, 1994

What causes heel spurs? Over 50% of 216 older people had heel spurs Odds of having a plantar calcaneal spur increased with certain pathologies e.g. 8x - obesity; 5x - heel pain; 3x - OA However, unrelated to radiographic measures of foot posture Menz et al. JFAR, 2008

Vertical compression? Research supports the theory that plantar calcaneal spurs are an adaptive response to vertical compression of the heel rather than longitudinal traction of the plantar fascia?

Vertical compression hypothesis Plantar heel spurs cannot be traction spurs They do not develop within the plantar fascia Spurs develop on the deep surface of the fascia They can reform after fascial release Spurs are a response to mechanical stress Due to adaptive response to changes in loading or an attempt to change loading patterns to minimise further damage Kumai & Benjamin, J Rheumatol, 2002

Abreu et al: Skeletal Radiol 2003.

Ultrasonography

Ultrasonography Proximal plantar fascia (PF vs control) 2.2 mm thicker 105x more likely to have thickness >4 mm 204x more likely to have hypochogenicity If you want the complete methods and statistics including 95% CIs, please consult Andrew’s article in JFAR.

Courtesy of: Jason De Luca, Southern Cross Medical Imaging, Bundoora Plantar fascia usually has a linear fibrillar appearance <4 mm. Plantar fasciopathy has >4 mm thickness, decreased echogenicity and mild increased vascularity. Courtesy of: Jason De Luca, Southern Cross Medical Imaging, Bundoora

Ultrasonography – Power Doppler Is there a vascular component?

Vascularity – Walther et al. 2004 1 2 3 4

McMillan et al, unpublished Case-control study 30 cases (with PF) and 30 controls Investigated vascularity (hyperaemia) within the fascia using power Doppler ‘mild hyperaemia’ – PF cases 5x more likely to have vascular in-growth No correlation between grade of hyperaemia and duration of symptoms

Magnetic Resonance Imaging (MRI) Proximal plantar fascia (PF vs control) 3.4 mm thicker

T1 weighted MRI image demonstrates abnormal signal in and thickening of the proximal plantar fascia

Magnetic Resonance Imaging (MRI) Are there any other changes? Bone?

MRI: T2 fat suppressed sagittal image demonstrates abnormal signal in proximal plantar fascia as well as bone marrow oedema (thick arrow) Fat suppressed T2 weighted MRI demonstrates abnormal signal in proximal plantar fascia as well as bone marrow oedema (thick arrow)

Chimutengwende-Gordon et al Foot Ankle Int 2010 Axial STIR image demonstrating calcaneal bone marrow oedema Sagittal STIR image demonstrating soft tissue and bone marrow oedema

Summary of imaging for PHP X-rays Spurs (check for # spurs) Ultrasound Thicker (> 4 mm thick), hypoechogenicity, mild vascularity MRI Increased thickness and signal, plus bone marrow oedema (stress reaction/stress #)

Future research

Conclusion Heel spurs are associated with PHP The fascia is often degenerated There can be swelling in and around the fascia There can be bone marrow oedema Therefore, there appears to be both fascia and bone pathology