Heel Spurs

What are Heel spurs?

The plantar calcaneal (Heel) spur has been classically described as a bone outgrowth localised just anterior to the medial tuberosity of the calcaneus. This can not often be palpated clinically, but only seen radiologically as shown in the x-ray on the right below.

Are Heel Spurs the Cause of My Heel Pain?

Short answer: No

Long Answer:
This issue is very controversial with no definitive agreement that a heel spur causes damage or trauma to the surrounding tissues.
Historically, it has been commonly accepted that heel spur formation is an abnormal finding and very closely correlated with the symptoms of heel pain.
In the past it was reported that excessive traction (pulling) of the plantar fascia on its attachment at the heel resulted in chronic inflammation, which in turn resulted in a reactive ossification and subsequent extra bone forming in the shape of a ‘spur’.
This is perhaps why heel spurs and ‘plantar fasciitis’ are still to this day thought by many to be one entity.  Does the traction and inflammation cause a heel spur, or does a heel spur cause tissue inflammation?.  It is not uncommon to see statements that ‘plantar fasciitis’ is caused by heel spurs (admittedly this is on websites rather than academic journals), but is this correct?
To investigate this it is important to look at the literature investigating heel spurs.
1. How common are heel spurs?

Studies have shown that heel spurs are more common in pain free individuals than first thought, and it has been reported that anywhere between 11 and 27% of the population have radiographic evidence of a spur.5,8-13

Clearly this suggests they are not always associated with symptoms, and are not necessarily considered as ‘abnormal’ as once thought.

Interestingly, even a study performed over 50 years ago on 323 patients concluded that the plantar calcaneal spur was never the cause of pain and probably a normal manifestation of the aging process.14

However, the research does suggest that calcaneal spurs do seem to be over-represented in certain groups, such as females,10,11,13 individuals with osteoarthritis15,16 and older people.11,13,15,16 Calcaneal spurs have also found to be more common in those who are overweight.17

2. What are heel spurs?

It has long been thought that heel spurs, plantar fascia problems and heel pain were linked. It was thought the spur was a result of increased traction of the plantar fascia which resulted in the formation of the spur. Anatomic studies contradict this and report that the spur is found above the plantar fascia.4,12,18

Some found it was much more commonly located in the other intrinsic musculature, (namely Flexor Digitorum Brevis and Abductor Digiti Minimi)4,18,19 and one study concluded that spurs do not develop within the plantar fascia.20

What is clear is that there is huge variability in the location of heel spur formation and  its link to plantar faciitis is not credible.

3. What causes heel spurs?

The traditional theory for formation of plantar calcaneal spurs refered to as the longitudinal traction hypothesis, i.e. the plantar fascia pulling on the heel bone and causing the formation of a spur.  Despite the anatomical studies showed that the spur is far from consistently found in the fascia, it has been suggested that there could be an element of tensile force exerted on the calcaneus from a variety of the other structures which attach to it.4,19

An alternative theory, termed the vertical compression hypothesis16 and was proposed by Kumai and Benjamin in 2002.20 This theory suggests that calcaneal spurs are outgrowths which form in response to repetitive vertical stress in an attempt to protect against microfractures.  This idea is supported by histological studies which show that the bony trabeculae are NOT aligned in the direction of soft tissue traction.16,18 Li and Muehleman18 found that the direction of the trabeculae suggested that the force causing the pathological response was consistent with the external ground reaction force vector.

So what does all this mean in plain English?  It means that we used to think a spur was caused by the plantar fascia pulling on the bone.  This is highly unlikely as the spur is seldom found in the plantar fascia.
If traction is the cause it is more likely to be caused by other musculature such as Flexor Digitorum Brevis or Abductor Digiti Minimi.  However these bony protrusions could instead be caused by the repetitive vertical loading (the heel continuously hitting the floor, and the floor of course hitting it back) with the spur forming as a protective mechanism.
We also know that anywhere up to a quarter of the population may have a heel spur, but this will not always be problematic.

What is causing my Heel Pain if not Heel Spurs?

It is chronic degeneration of the plantar fascia which has been called Plantar Fasciitis or Plantar Fasciiosis  
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PLANTAR FASCIITIS

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