Injection Therapy for Common Chronic Pain Conditions of the Foot

Injection Therapy for Common Chronic Pain Conditions of the Foot

Karina Charipova

Kyle Gress

Ivan Urits

Omar Viswanath

Hisham Kassem

Alaa Abd-Elsayed


Interventions to alleviate chronic foot pain range from conservative measures such as rest to semi-conservative approaches like injections, all of which aim to avoid invasive surgery. Historically, costly surgical interventions with questionable efficacy have been deployed at a cost to Medicare of almost a billion dollars a year.1 Here, the authors will present semiconservative measures as an alternative to invasive procedures.


There are a variety of injectable substrates that, through different mechanisms, have the potential to provide relief to chronic foot pain.


Corticosteroids are the mainstay of treatment, the old guard. They have been used extensively for nonsurgical treatment of inflammatory and degenerative conditions.2 Through a complex mechanism that acts directly on the nuclear steroid receptor, these injections interrupt the inflammatory and immune cascade to help decrease swelling, redness, and tenderness at the site of action.3

Hyaluronic Acid

Hyaluronic acid is a naturally synthesized glycosaminoglycan that occurs in the synovial fluid of joints after being created by fibroblasts, chondrocytes, and synovial cells. In diseased, inflamed, and osteoarthritic joints, hyaluronic acid is diluted through the invasion of inflammatory cytokines, free radicals, and proteolytic enzymes.4 The dilution process prevents hyaluronic acid from acting as a shock absorber and lubricant.4 Augmentation of affected joints with additional injected hyaluronic acid resets the balance within the synovial fluid and provides the elasticity needed to protect the surrounding bone.3


Alcohol injections are usually mixed with local anesthetic and have been used for approximately the past 20 years.5 The goal of this treatment is to stimulate chemical neurolysis to prevent the transmission of painful stimuli from the periphery to the central nervous system.6 This technique is usually reserved for neuromas that are refractory to other treatments.

Platelet-Rich Plasma

Platelet-rich plasma (PRP) supercondenses degranulated platelet growth factors along with naturally occurring thrombin and cytokines to help speed up the naturally occurring growth process.7 This happens specifically via the improvement of chondrogenesis, cell proliferation, angiogenesis, cell differentiation, and bone remodeling, among other processes.8 It is hypothesized that over 300 distinct proteins could be involved in these injections.9 It should
be noted that PRP injections are significantly more expensive than both corticosteroid and hyaluronic acid injections.

Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are naturally appearing cells that have a slew of capabilities including anti-inflammatory properties, immune regulation, and immune suppression.3 There are a number of proposed mechanisms that explain how these cells function, but at this time consensus is lacking.9 MSC, albeit used for the treatment of chronic foot pain, is poorly understood and is far more expensive than most other available treatments.


Capsaicin, a natural chemical found in hot peppers, serves as an agonist to the vanilloid receptor. This receptor naturally responds to noxious stimuli that are associated with the burning sensation that results from consumption of spicy foods.10 While a side effect of the injection is a local burning sensation, it does have the capacity to provide a transient, reversible loss of nociceptor afferents that help with a temporary reduction of pain.11

Amniotic/Placental (Clarix Flo) Injections

Amniotic membrane/umbilical cord-based particulate injections have recently been researched to determine potential efficacy in a variety of conditions. Like other biologic products, amniotic membrane/umbilical cord-based injectables aim to accelerate healing and regeneration using allogenic growth factors.12 Clarix Flo is the only one currently available on the market. It has been studied as an intervention for multiple different disease processes in the lower extremities. In a randomized trial in patients with plantar fasciitis, cryopreserved amniotic membrane injections are compared similarly in efficacy to corticosteroid injections with a better safety profile.13 In limited data, these injections showed to have beneficial effects in patients with chronic diabetic foot ulcers.14 Another recent study showed that, when compared to saline treatment, treatment with amniotic membrane/umbilical cord injections correlated with a slowing of the osteoarthritis disease process.15 A 2020 study looked at injections as a treatment for lower extremity neuropathy, with findings showing positive response including reduction of pain and no complications.16 While still needing more research, amniotic membrane/umbilical cord injections provide a potentially promising future of safer, more effective injectables useable for a whole host of ailments.

Sep 8, 2022 | Posted by in ORTHOPEDIC | Comments Off on Injection Therapy for Common Chronic Pain Conditions of the Foot

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