Ultrasound-guided hydrodissection is a minimally invasive procedure used to treat certain nerve entrapment conditions, including carefully selected cases of Baxter's nerve entrapment. Rather than treating the plantar fascia itself, the aim of hydrodissection is to improve the movement of the irritated nerve by gently separating it from the surrounding tissues that may be causing compression or irritation.
The term hydrodissection simply means using fluid to create a small plane between a nerve and the tissues surrounding it. Under continuous ultrasound guidance, a fine needle is placed adjacent to Baxter's nerve and fluid is carefully injected around the nerve. As the fluid spreads, it gently separates the nerve from adjacent fascia, muscle and connective tissue, reducing mechanical tethering while preserving the surrounding structures.
Ultrasound guidance is one of the most important parts of the procedure. Baxter's nerve is small and lies close to blood vessels, muscles and the plantar fascia. Performing the procedure under real-time ultrasound allows the nerve, needle tip and injected fluid to be visualised throughout the treatment. This improves procedural precision and helps minimise the risk of unintentionally injecting nearby structures.
One of the common misconceptions is that hydrodissection is simply another cortisone injection. It is not. The primary objective is mechanical rather than anti-inflammatory. The injected fluid physically separates the nerve from surrounding tissues, potentially allowing it to glide more freely during movement. Depending on the clinical situation, different solutions may be used, including local anaesthetic, normal saline, dextrose or other medications where appropriate. The choice of solution depends on the diagnosis, current evidence and the treating clinician's judgement.
For patient comfort, I commonly perform an ultrasound-guided local anaesthetic before proceeding with the hydrodissection itself. Most patients tolerate the procedure well, and because the entire treatment is performed under ultrasound guidance, they are able to see the procedure on the screen if they wish. Following treatment, patients are usually able to walk out of the clinic, although temporary activity modification is often recommended during the early stages of recovery.
Hydrodissection should not be viewed as a stand-alone treatment. If the mechanical factors contributing to nerve irritation are not addressed, symptoms may recur. Appropriate footwear, rehabilitation, strengthening, load management and treatment of any coexisting plantar fasciosis remain important parts of recovery. The procedure is intended to complement these treatments rather than replace them.
Because Baxter's nerve entrapment is relatively uncommon and frequently underdiagnosed, treatment decisions should always be individualised. Hydrodissection is not appropriate for every patient with heel pain. It is most likely to be considered when the diagnosis has been established, conservative treatment has not produced sufficient improvement and the clinical assessment suggests that nerve compression is a significant contributor to the patient's symptoms.
As our understanding of chronic heel pain continues to evolve, ultrasound-guided hydrodissection represents another example of how accurate diagnosis allows treatment to be directed at the true source of pain. Rather than assuming every painful heel is caused by the plantar fascia, identifying nerve involvement opens the possibility of treatments specifically designed to address nerve entrapment while avoiding unnecessary or ineffective interventions.