The Ankle Block for Diabetic Peripheral Neuropathy

Written by Gisele J. Girault, MD

Updated September 2026 ·10 min read

Diabetic peripheral neuropathy is one of the most common pain problems in an interventional practice and one of the least amenable to a single injection, because the damage is not at one point. It is length-dependent: the longest nerves fail first, which is why the feet go before the hands.

Dr. Gisele J. Girault starts from that anatomy. Diabetic neuropathy “affects the longest nerves in the body first” — the sciatic nerve — so what presents clinically is its terminal branches, in the foot.

Her response to that is not to chase a focal target but to treat the whole foot at once, using a technique borrowed from anaesthesia. This reference covers the five nerves involved, how the block is performed and dosed, how it is scheduled, and where it sits among the alternatives. It sits under our clinical reference to joint and extremity injection.

The five nerves of the ankle

An ankle block anaesthetises the foot by blocking the five nerves that supply it, and Girault’s point is that learning where each one runs makes the whole foot accessible — “if you learn your anatomy and you kind of learn which nerve goes where, you can actually block any of these nerves if the patient is having pain in those areas.”

• Sural nerve — just posterior to the lateral malleolus
• Superficial peroneal nerve — anterolateral ankle, superficial
• Deep peroneal nerve — close to the superficial peroneal on the anterolateral side
• Saphenous nerve — anterior to the medial malleolus
• Posterior tibial nerve — behind the medial malleolus, the same nerve compressed in tarsal tunnel syndrome

The overlap with tarsal tunnel is worth noting rather than glossing. The posterior tibial nerve is a target in both, and a patient can have a focal compression at the tunnel superimposed on a generalised neuropathy. That combination is covered in tarsal tunnel syndrome, where Girault notes it as the reason results at the ankle are less reliable than at the wrist.

How the block is performed

All five nerves sit close to the surface, and Girault’s technique follows from that.

She uses a 30-gauge half-inch needle and, because the nerves are so superficial, approaches at roughly 45 degrees for the sural and posterior tibial — up to 90 degrees depending on the patient — and much flatter for the anterolateral pair.

The efficiency in the technique is in that flat approach. Because the superficial and deep peroneal nerves lie near each other, she takes them with a single stick: entering nearly parallel to the skin and injecting as she withdraws, leaving a bead of solution beneath the skin that covers both.

Her sequence works around the ankle in turn — the peroneal pair anterolaterally, then the saphenous, then the posterior tibial behind the medial malleolus, then the sural behind the lateral malleolus — with roughly half a cc at each of the smaller targets.

Volume, and why it differs from a surgical block

This is the distinction that makes the technique a pain procedure rather than an anaesthetic one.

Girault uses about five cc in total across all five nerves: four cc of lidocaine and one cc of steroid. As she puts it, “it’s a classic anaesthesia ankle block. We’re just not using the same volume that we would use in an anaesthetic block if we were gonna do surgery on the foot — but it can be very effective.”

A surgical ankle block aims to abolish sensation for an operation, and uses volumes to match. This one aims to interrupt a pain pattern and deliver steroid around irritated nerves, so the volumes are a fraction of that.

The reasoning behind steroid selection and cumulative exposure is set out in corticosteroid injections.

Scheduling and repeat

Girault runs this on the same structure she uses across her non-spinal injections, which keeps steroid exposure predictable rather than reactive.

The course is an injection every two weeks for a total of three. The series can be repeated approximately every six months.

Where a patient’s symptoms return before six months, this is one of the injections she supplements with straight lidocaine rather than advancing the steroid — managing the interval without accumulating dose. It is a pattern worth recognising, because she applies the same discipline to trigger points and to the forefoot.

What it can and cannot do

Being straight about this protects the patient from a disappointment the technique does not deserve.

The block treats symptoms. It does not repair damaged nerve, and it does not alter the course of the neuropathy — glycaemic control does that, and nothing injected at the ankle substitutes for it.

What it can do is interrupt a pain pattern well enough for sleep, walking and footwear to become tolerable, in a population where oral options are frequently limited by sedation, renal function or interactions. For patients already carrying a significant medication burden, a procedure that works locally has real value even when its effect is finite.

It also has diagnostic value. Foot pain that does not respond to a technically sound block of all five nerves is unlikely to originate in the foot, and the investigation should move proximally.

Related approaches

Dr. Robert Stall lists peripheral neuropathy among the conditions perineural injection therapy is used for — both diabetic neuropathy and neuropathy from other causes, including alcohol-related and toxic chemical exposures such as occupational exposure and Agent Orange. That technique uses sterile 5% dextrose rather than steroid and anaesthetic, and is covered in perineural injection therapy.

On the diagnostic side, nerve conduction studies distinguish a generalised length-dependent neuropathy from a focal compression, and certain nerves are chosen specifically for their sensitivity to it. That selection is described in what a nerve conduction test diagnoses, along with an important limit: the study assesses large myelinated fibres, so small-fibre involvement — the burning and temperature-related pain many of these patients describe — can coexist with an entirely normal result.

For clinicians

The ankle block is a landmark technique across five targets, learned on live anatomy under supervision, and sound technique here depends on knowing each nerve’s position by palpation rather than by diagram. This reference carries no needle depths or trajectories for that reason. Empire teaches the ankle block alongside the foot and ankle injections across the pain management academy.