Author: Henry R Guly / Editor: Jason M Kendall / Reviewer: Jennifer Lockwood / Codes: C3AP2a, CAP33, HAP19, SLO4, TC2, TP7 / Published: 31/10/2017
Non-traumatic foot problems are common and usually present with pain and limping.
Foot and ankle problems commonly present in primary care and may also present to orthopaedic surgeons, podiatrists, rheumatologists and sports medicine clinics. This session does not cover all the causes of foot pain but concentrates on those that commonly present to emergency departments. Ankle pain and heel pain are covered elsewhere.
When a patient presents with non-traumatic foot pain, one does need to consider traumatic causes of pain which are either not remembered (perhaps because of dementia or they occurred while the patient was intoxicated) or if the trauma is not admitted (perhaps because of embarrassment due to the circumstances of the injury). Foreign bodies (e.g. a needle in the sole of the foot may occur without the patient realising it).
As with any other presenting symptom, the assessment of a patient presenting with foot pain consists of a history (including past medical history) and clinical examination:
- Look for deformity, scars, redness, swelling
- Feel for point of maximum tenderness, temperature
- Move all joints for range of movement, pain
- Examine neurovascular supply to the foot
- Pulses and other signs of ischaemia
- Sensation and power
The ankle should also be examined.
An examination for deformities (e.g. flat foot, pes cavus) necessitates an examination of the foot while the patient is standing.
The gait should also be examined.
To obtain a list of causes of foot pain one can think of the different tissues in the foot and the conditions that cause pain.
|Soft tissue problems||
Unless the cause of foot pain is obvious, foot x-rays will usually be required. However, foot x-rays may be normal initially in a variety of causes of foot pain including stress fracture, Freibergs disease, osteomyelitis and early Charcot foot. Other investigations, e.g. a repeat x-ray after an interval, a bone scan or MRI may therefore be required.
Diabetes mellitus may present with foot problems and so measurement of the blood sugar may be required.
Stress fractures are caused by overuse in the absence of a specific traumatic event. They are most common in young people especially:
- Military recruits
- Sportsmen and women
In the foot, stress fractures are most common in the 2nd MT but also occur in the 5th MT (Jones fracture).
In patients with osteoporosis, similar injuries occur without overuse and are called insufficiency fractures.
Confirming a Stress Fracture
The initial x-ray is frequently normal.
Patients with a suspected stress fracture should therefore be treated as for a fracture, even if they have a normal x-ray.
To confirm the diagnosis one can perform the following:
- Bone scan
- Repeat x-rays after two weeks
If it is important to confirm the diagnosis quickly, MRI or a bone scan should be used. However, as the management of a probable stress fracture of a second MT is unlikely to be changed by confirmation of the fracture, further x-rays after 10-14 days will usually be done and this will reveal a periosteal reaction (Fig 1).
Fig 2 shows a Jones fracture. This must be differentiated from the more common, avulsion fracture at the base of the MT (Fig 3).
In Jones fractures, there is a risk of non-union and so patients should be treated in a below knee POP and referred to an orthopaedic surgeon or sports injuries clinic.
Patients with stress fractures of the 2nd MT need to rest from running and similar exercise. They can continue with cycling and other non-impact sport but will need advice on a graded return to sport.
Freibergs disease is an avascular necrosis of the MT head which is most common in the 2nd MT but also occurs in the 3rd MT. It is of unknown aetiology. It may present acutely with pain and be thought to be a stress fracture and initial x-rays may be normal though abnormalities (deformity and fragmentation of the MT head) will develop over a few weeks. It may also be picked up as an incidental finding on an x-ray.
Treatment should be conservative initially as acute symptoms usually improve. A metatarsal pad to take the weight off the painful area may be useful. A patient with chronic pain, not helped with simple measures may need podiatry or orthopaedic referral for assessment and further treatment. Asymptomatic Freibergs disease, found incidentally, requires no treatment.
Mortons metatarsalgia is caused by a neuroma (Mortons neuroma), usually between the 3rd and 4th MT heads. There is typically pain and tenderness in that area and the pain is provoked or made worse by compressing the foot from side to side. On sensory testing, there may be altered sensation on opposing surfaces of the 3rd and 4th toes.
The diagnosis can be confirmed with ultrasound or MRI.
Treatment is usually with injection therapy or surgery. However a Cochrane report says that there is insufficient evidence with which to assess the effectiveness of surgical and non-surgical interventions for Mortons neuroma .
Fig 1: Mortons neuroma
Pain in the first metatarso-phalangeal (MTP) joint
The most common cause of the acutely red, hot painful 1st MTP joint in a middle aged or elderly patient is gout. However there are other causes of pain in this joint.
This joint is a very common site of osteoarthritis. This is usually a chronic problem presenting more as stiffness (hallux rigidus) than pain but acute exacerbations may occur. A common error is to measure the serum uric acid in a patient with osteoarthritis and, if it is elevated, to make an erroneous diagnosis of gout. Patients may be helped with a metatarsal pad but definitive treatment is surgical.
Hallux valgus is a common deformity at this joint. The bony lump that results from this is called a bunion and a bursa may overlie this. Treatment (if required) is surgical .
A similar condition occurs less often at the 5th MTP joint (sometimes called a bunionette).
Other causes of arthritis also occur, including rheumatoid arthritis (and similar inflammatory diseases) but this is usually a symmetrical polyarthritis and does not tend to present to the emergency department. Gout can occur in any joint and not just the 1st MTP joint.
Much forefoot pain is caused by abnormal foot mechanics, e.g. flat foot. Patients may need investigation by a podiatrist.
Many causes of forefoot pain can be helped with custom-made orthoses .
Skin and subcutaneous tissue problems, e.g. verrucae can also present with foot pain.
Patients with diabetes are at particular risk of foot problems including:
- Painful peripheral neuropathy
- Charcot joints
Overall, 2040% of people with diabetes have neuropathy and 2040% have peripheral vascular disease. These are secondary to poor blood glucose control and adverse arterial risk factors (e.g. smoking or dyslipidaemia). Around 5% of people with diabetes may develop a foot ulcer in any year, and amputation rates are around 0.5% per year.
Patients are at increased risk if they have neuropathy and/or vascular disease and at high risk if they have either of those in association with foot deformity or skin changes or if there is a history of previous ulceration. Their risk is also increased if they are unable to self-care .
NICE advises patients to seek advice from a healthcare professional if they note any colour change, swelling, breaks in the skin, pain or numbness.
Health care professionals are advised to refer patients to a multidisciplinary foot care team within 24 hours if any of the following occur:
- New ulceration or wound
- New swelling
- New discolouration (if either the whole foot or part of a foot becomes redder, bluer, paler or blacker)
NICE also recommend that people with suspected or diagnosed Charcot osteoarthropathy should be referred immediately to a multidisciplinary foot care team .
Patients with critical ischaemia (rest or night pain; pale/mottled feet; dependent rubor; ischaemic ulceration or gangrene) will need surgical referral .
NICE guidance recommends that care for the diabetic foot will occur via diabetic clinics and primary care but these patients often attend the ED either with their foot problems or their foot problems are discovered incidentally when a patient attends the ED for another diabetes-related problem.
Charcots foot is a neuroarthropathic process with osteoporosis, fracture, acute inflammation and disorganisation of foot architecture. Acutely, it is associated with increased bone blood flow, leading to increased warmth. The diagnosis is based on the appearance of a red, swollen oedematous and possibly painful foot in the absence of infection, though during the acute phase, the two can be difficult to distinguish. A normal x-ray initially does not exclude a Charcots foot  or osteomyelitis .
Later, it can become quiescent with increased bone formation, osteosclerosis, spontaneous arthrodesis and ankylosis. SIGN guidelines say that there is insufficient evidence to recommend the routine use of MRI or bone scanning to distinguish acute Charcots foot from osteomyelitis. They therefore recommend that the diagnosis should be made by clinical examination supported, where available, by the use of thermography .
Diabetic foot ulcers presenting to the ED should be debrided as much as is possible as the later that debridement takes place the more likely a patient is to have osteomyelitis .
Chronic foot pain may result from altered biomechanics such as congenital tarsal coalitions or fusions. If one joint is fused or very stiff, forces through adjacent joints will be greater and degenerative disease occurs.
Accessory bones are usually asymptomatic incidental findings but they can occasionally give pain. An accessory navicular will usually only be noticeable by a painless lump but it can become painful after trauma. An os trigonum occurs when the posterior process of the talus forms as a separate bone. It is usually asymptomatic but can give problems in those who put excessive force through their ankles (e.g. dancers).
Toe nail problems
The most common painful non-traumatic toe problem is an ingrowing toe nail (IGTN). This may result from a nail abnormality but is more likely to result from a soft tissue problem. They may present with infection. Mild cases can be treated by trying to elevate the nail corner. Antibiotics are rarely helpful but may be needed if there is cellulitis. There is a very high recurrence rate with simple nail removal and so these patients should be referred to a chiropodist or podiatrist for definitive treatment. However if there is severe infection (e.g. a paronychia), the nail may need to be removed to allow the infection to settle.
Subungal exostosis may present as an IGTN but closer examination will reveal a hard bony lump. X-rays will confirm the diagnosis. Exostoses that cause problem need surgical excision.
Onychogryphosis (Rams horn deformity of the nail) should not present to the ED but untreated onychogryphosis may be found in patients who have neglected themselves. Patients need a chiropody or podiatry referral.
Fungal nail infections are common.
Tumours may (rarely) present as nail problems. Subungal melanoma must not be missed.
Neurological causes of pain
Another cause of a painful foot in diabetic patients is painful diabetic peripheral neuropathy. However this would not commonly present to the ED but may be an incidental complaint in diabetic patients presenting with other conditions. This pain can be treated with tricyclic antidepressants or gabapentin .
Complex regional pain syndrome (reflex sympathetic dystrophy) may complicate a minor injury and so may present to an ED (e.g. as continuing pain following a sprained ankle). The features include regional pain, sensory changes (e.g. allodynia), abnormalities of skin temperature and colour, abnormal sweating and oedema. It usually occurs after trauma. If this occurs early after an injury, physiotherapy is considered to be of value though the evidence is not good .
Tricyclic antidepressants or gabapentin may be useful or the patient may need referral to a specialist pain clinic. .
Tarsal tunnel syndrome is an entrapment neuropathy of the posterior tibial nerve in the tarsal tunnel. Patients present with pain and parasthesiae in the heel, foot and toes. Initial treatment is conservative but if it does not improve, steroid injection or surgery may be needed.
Patients with non-traumatic foot problems will not normally be followed up in the ED but should usually be referred to their GP or another agency.
Some foot problems (e.g. ischaemia, some diabetic foot problems) are urgent and will be referred within the hospital according to local guidelines.
Take foot problems in diabetes very seriously.
Initial x-rays may be normal in:
- Stress fracture
- Freibergs disease
- Charcot foot
- Thomson CE, Martin D, Gibson JA. Interventions for the treatment of Mortons neuroma. Cochrane Database of Systematic Reviews 2004, Issue 3. Art. No.: CD003118. DOI: 10.1002/14651858.CD003118.pub2 View review
- Ferrari J, Higgins JPT, Prior TD. Interventions for treating hallux valgus (abductovalgus) and bunions. Cochrane Database of Systematic Reviews 2004, Issue 1. Art. No.: CD000964. DOI: 10.1002/14651858.CD000964.pub2. View review
- Hawke F, Burns J, Radford JA et al. Custom-made foot orthoses for the treatment of foot pain. Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD006801. DOI: 10.1002/14651858.CD006801.pub2. View review
- National Institute for Health and Clinical Excellence. Clinical Guideline 10. Type 2 diabetes: prevention and management of foot problems. 2004; London: NICE. View guideline
- Scottish Intercollegiate Guidelines Network. Clinical Guideline 116. Management of diabetes: a national clinical guideline. 2010; Edinburgh: SIGN. View guideline
- Houltram C. A plain radiograph does not detect Charcots osteoarthropathy in stage 0. BestBETs, 2007. View report
- Houltram C. A normal plain radiograph does not always exclude osteomyelitis as a diagnosis. BestBETSs, 2007. View report
- Houltram C. The diabetic foot wound- can debridement wait? BestBETs, 2007. View report
- Callaghan M, McKearney G. Hydrotherapy for Complex Regional Pain Syndrome (CRPS) of the foot and ankle. BestBETs, 2006. View report
- Royal College of Physicians. Complex regional pain syndrome in adults. UK guidelines for diagnosis, referral and management in primary and secondary care. London: RCP, 2012. View guideline