The end of a calendar year may be a time to reflect on personal achievements, but for many, the cold winter months are a time when hard fitness training continues with spring and summer sporting goals in sight. Heel pain remains one of the most miserable interruptions to sporting activity or day to day life and is frustrating for the athlete and doctor alike as Mr Michael Oddy, ISEH Consultant Trauma & Orthopaedic Surgeon reports.
"The cause of heel pain varies according to its location which generally is either at the back of the posterior heel commonly associated with the disorders of Achilles’ tendon attachment, or beneath the pad on the sole as plantar heel pain. The plantar heel pad is a specialised shock absorbing structure consisting of a network of chambers of fat approximately two centimetres thick with tough yet elastic walls that are stabilised to the under surface of the calcaneum heel bone. The calcaneum itself has a thin cortical bone surface and is predominantly made of less dense cancellous spongy bone. A band of dense fibrous tissue, the plantar fascia also arises from the under surface of the calcaneum, extending forwards through the sole of the foot to the base of the toes, acting like a fixed length guy-rope supporting the arch of the foot.
The clinical signs associated with plantar heel pain are fairly limited in the absence of an acute fracture. Bruising and swelling are rarely seen and most findings relate to the location of direct tenderness. Prolonged standing or repetitive direct impact to the heel pad in poorly cushioned shoes can lead to a stone bruise; there is rarely any structural damage to the heel fat pad and often no clinical tenderness despite the patient being able to localise their pain. An increase in activity with pain felt progressively earlier during training and tenderness with side to side compression may indicate a calcaneal stress fracture, a mismatch in accumulation versus repair of micro-cracks in the bone trabeculae.
Plantar fasciitis is probably the commonest and most widely known cause of plantar heel pain. The pathology is similar to disorders of the Achilles’ tendon and often there is little evidence for true inflammation hence the term fasciopathy is often favoured. An increase in repetitive loading activity, increase in body weight or inappropriate shoe wear leads to the characteristic start up pain and stiffness caused by degenerative micro-tears and a disordered healing response. Clinical examination demonstrates direct tenderness in the central heel pad made worse with upward dorsiflexion of the toes which stretch the fascia by the biomechanical windlass mechanism of Hicks. Tightness in the Achilles’ tendon leading to reduced upward ankle dorsiflexion or signs of insufficient function in the tibialis posterior tendon leading to a progressive flat foot and increased strain on the plantar fascia may both be associated with the development of plantar fasciitis.
The diagnosis of plantar fasciitis is made predominantly on clinical grounds with investigation reserved for atypical symptoms or a failure to respond to treatment. A plain X-ray may show a bony heel spur which is common in the population and not believed to be the cause of any significant problems. Stress fractures or fat pad bruising are best visualised on a Magnetic Resonance Imaging (MRI) scan which can also demonstrate thickening of the plantar fascia. Ultra-sound scanning performed by an operator skilled in musculo-skeletal imaging is probably the most useful modality to image the plantar fascia and can demonstrate thickening and intra-substance degenerative tears.
Compliance with treatment is key to the treatment of plantar fasciitis with recalcitrant cases usually the result of an inconsistent approach. Cessation of impact loading, the use of a cushioned gel pad, insole or resting splint, avoidance of barefoot walking and a focused stretching programme are key interventions for early symptom control. Image-guided steroid cortisone injections can give good symptom relief although when repeated can risk rupture of the fascia and atrophy with wasting of the fat pad. Extra-corporeal shock-wave ultrasound therapy can similarly be effective although the exact mechanism of action is not clear. Partial surgical release is reported with either open or keyhole endoscopic techniques have advocates but are generally rarely performed.
Plantar heel pain recalcitrant to a well-worked clinical algorithm or consistent clinical interventions should also alert one to other causes such as referred spinal nerve root irritation or a soft tissue to bone attachment enthesitis due to an inflammatory arthritis. Finally, if a seasonal mythical figure laden with gifts is spotted trying to land on a roof to climb down a chimney, A Year on Foot at the ISEH warns about the risk of heel bone calcaneal injury falling from a height which has a potentially far more devastating long-term outcome than plantar fasciitis."