Approach to foot pain: Clinical sciences

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Introduction0:00–0:35

Foot pain is a common symptom with many underlying causes, including conditions affecting the joints, bones, tendons, or skin.
It’s important to first identify if your patient’s foot pain is due to trauma or infection. Other possible types of foot pain include neuropathic pain due to nerve damage; nociceptive pain due to arthralgia, ostalgia, or tendinopathy; and dermatologic ulcers or lesions.

Focused H&P0:35–0:56

When a patient presents with foot pain, first obtain a focused history and physical exam. History typically reveals foot pain, while the exam might demonstrate foot edema, erythema, or warmth.
They may also have foot tenderness, effusion, limited range of motion, or crepitus. Your next step is to assess for trauma.

Trauma0:56–2:13

This includes an obvious mechanism of injury, such as a motor vehicle crash or sports injury, joint deformity, or ligamentous laxity.
If trauma is present, think fracture or dislocation, and investigate further. Patients with a fracture or dislocation will report pain that may worsen with activity and improve with rest.
They might also report bruising. Physical exam will reveal tenderness to palpation and difficulty bearing weight.
With these findings, consider a traumatic injury, such as a fracture or dislocation, and order a foot X-ray. If the X-ray results confirm a bone fracture or joint dislocation, diagnose a foot fracture or dislocation!
Now, here’s a clinical pearl to keep in mind! Stress fractures are caused by repetitive stress, such as frequent running, marching, or dancing.
Patients with this condition may have a history of osteoporosis, tobacco use, vitamin D deficiency, or calcium deficiency.
Their initial X-rays might be negative or show a faint fracture line, while an MRI typically shows fracture or osseous remodeling.
Alright, if trauma is not present, assess for signs of infection like fever, chills, myalgias, and localized tenderness.

Osteomyelitis2:13–3:31

If there are signs of infection, think osteomyelitis. Patients with osteomyelitis often have a history of diabetes mellitus, tobacco use, immunocompromised status, or chronic foot ulcers.
Physical examination may reveal that the foot is tender to palpation with edema, erythema, and warmth. There might be fistula tracts or ulcerations on the foot as well.
Based on these findings, consider osteomyelitis and order labs, including blood cultures, CBC, and inflammatory markers like ESR and CRP.
Also, make sure to order imaging, including an X-ray and an MRI. Labs will reveal positive blood cultures, possibly with leukocytosis; and the ESR and CRP could be elevated.
The X-ray can be normal or may show overlying soft tissue swelling with cortical bone destruction and an underlying lucent bony lesion; while the MRI typically reveals bone marrow edema and overlying periosteal and subcutaneous edema.
In this case, diagnose osteomyelitis. On the other hand, if there are no signs of infection, assess for neuropathic foot pain.

Neuropathic Foot Pain3:31–4:55

This type of pain is lancinating, electrical, radiating, burning, or cold in nature. If neuropathic pain is present, the patient might report a history of numbness and tingling in their feet, as well as a history of a systemic disease associated with neuropathy, such as diabetes mellitus or multiple myeloma.
Physical exam reveals an abnormal monofilament exam, decreased sensation to pinprick, and possibly allodynia, which is when pain is elicited from something that typically doesn’t cause pain, like a feather.
Although these findings strongly suggest neuropathy, you might need to order a nerve conduction velocity study, or NCV, and an ultrasound or MRI to confirm.
If the NCV shows an abnormal nerve conduction and if imaging shows nerve compression, diagnose neuropathy. And here’s another clinical pearl!
There are many possible causes of neuropathic foot pain. Peripheral neuropathy can lead to sensory loss and decreased ankle reflexes.
Another possible underlying condition is nerve entrapment, such as tarsal tunnel syndrome, which results from compression of the tibial nerve as it passes under the flexor retinaculum of the ankle.
Lastly, Morton neuroma is caused by recurrent compression of one of the common plantar digital nerves. Okay, if neuropathic foot pain is not present, assess for nociceptive foot pain.

Nociceptive foot pain4:55–5:19

This type of foot pain is localized, dull, or sharp. It does not radiate, has an identifiable pain source, and usually involves joints, bony structures, soft tissues, or skin.
If this is the case, assess the primary tissue involvement to determine the source of the pain. First, let’s discuss arthralgia.

Arthralgia5:19–6:38

These patients may have a history of joint stiffness, fatigue, or malaise. The exam may show joint erythema, edema, and warmth with possible joint deformity, limited range of motion, or crepitus.
If this is the case, diagnose arthralgia. Here’s another clinical pearl to keep in mind!
Common causes of foot arthralgia are osteoarthritis, crystal arthropathy, rheumatoid arthritis, and hallux valgus. Osteoarthritis is a degenerative disease of the joints, characterized by mechanical wear and tear injury to articular cartilage, resulting in bony and synovial damage.
On the other hand, rheumatoid arthritis is a chronic, autoimmune disorder that involves symmetric inflammation of the synovial joints, leading to joint effusion with eventual destruction of cartilage and bones.
Crystal arthropathy is the cause of ankle pain in patients with a history of high purine diet, diuretic use, or alcohol use.
Finally, hallux valgus, commonly called a bunion, can be an underlying cause of arthralgia. It occurs when the first metatarsophalangeal joint is poorly aligned, resulting in medial deviation of the great toe that can cause pain and stiffness.
Next up is ostalgia, also known as bone pain. Patients may report a history of osteoporosis, obesity, increased activity, or tobacco use.

Ostalgia6:38–7:23

The physical examination will reveal a foot that’s tender to palpation, with possible edema or erythema, and difficulty bearing weight on the affected foot.
With these findings, diagnose ostalgia. Here’s a clinical pearl!
A common cause of ostalgia in patients with foot pain is a calcaneal spur, often called a heel spur. This condition results from poor-fitting shoes or chronic plantar fasciitis.
In this case, you can get an X-ray which will show a bony protrusion from the calcaneal tuberosity. Alright, now let’s move on to strains and sprains.

Strains and Sprains7:23–8:34

These patients may report increased activity or a recent injury. The exam often reveals tenderness to palpation, edema, painful range of motion, and antalgic gait, or walking with a limp due to pain, but without any gross deformity or significant ligamentous laxity.
If this is the case, diagnose a strain or sprain, which may affect muscle, ligaments, tendons, and fascial structures. Here’s another clinical pearl!
Plantar fasciitis is a very common cause of foot pain. Patients with this condition tend to complain of plantar pain near the heel, most notably with the first few steps after a period of non-weight bearing.
And here’s another clinical pearl! Posterior tibial tendinopathy presents with pain near the medial malleolus of the ankle that extends to the instep and arch.
Since this tendon supports the arch of the foot, long-term strain can threaten the stability of the tendon, resulting in a collapse of the medial longitudinal arch, and causing flat foot deformity in adults.

Dermatologic Ulcers/Lesions8:34–10:14

Finally, let’s discuss dermatologic foot pain. These patients may have a history of skin changes, itching, non-healing foot wounds, malnutrition, decreased mobility, or diabetic neuropathy.
On physical exam, the affected skin is tender to palpation. You might also see rashes, skin ulcers, or singular skin lesions, along with fissures and hyperkeratosis.
If this is the case, diagnose dermatologic ulcers or lesions as the cause of your patient’s foot pain. Here’s a clinical pearl!
Skin ulcers can have various causes. For example, patients with diabetes might be at increased risk of developing foot ulcers due to peripheral neuropathy, trauma, or ischemia.
Vascular abnormalities, such as venous hypertension, can result in foot ulcers, even when diabetes is not present. Additionally, pressure ulcers can occur on the feet of patients who have decreased mobility.
And here’s one more clinical pearl to keep in mind! Dermatologic foot pain can have a variety of underlying causes.
Plantar warts, for example, are viral infections that can become painful in some patients. On the other hand, tinea pedis is a fungal infection of the skin on the feet which is usually itchy but can develop painful fissures near or between the toes.
Lastly, mechanical keratosis, also known as corns and calluses, can also cause foot pain. These skin lesions result from repetitive friction or pressure on the feet, which causes the affected skin to thicken and, in some cases, become painful.
Alright, as a quick recap… Foot pain is a common symptom that can have many underlying causes. When evaluating a patient with foot pain, first, assess for trauma leading to a fracture or dislocation.

Review10:14–10:42

Next, assess for infection, like osteomyelitis. If trauma or infection are not present, characterize your patient’s pain as neuropathic pain due to underlying neuropathy or nociceptive like arthralgia, ostalgia, strains or sprains,