Pain after injections for nail surgery

Pain after injections for nail surgery is brought this month to readers by Alison Charlton. Alison is an avid reader of  Podiatric Reflective Newsfeed and publishes her short case history for ConsultingFootPain. Many queries are being raised on Podiatry Forums covering nail surgery. If you have a case to share or query, you can write to ConsultingFootPain. (Editor)

Presentation and Complaint

Mycotic nail causing deformation. This is only a typical example.

A 42-year-old female attended the clinic for the removal of her heavily mycotic nail (the illustration is not the patient).  The nail was causing discomfort due to its thickness. She was taking no medication, had no allergies, and had normal vascular and neurological tests. She is a keen runner, running many marathons and averaging 30 km weekly. She is a busy mum with two children.

https://www.dreamstime.com/photos-images/signing-consent.html

Consent & Procedure

After lengthy discussions and outlining treatment options, she chose to have a TNA with phenol. The injection was from one side using the ring block method (see method below). The nail avulsion was uneventful, although the nail bed required more scraping than normal to clear it. 


Post-treatment sequela

The wound healed within four weeks. At 5 weeks post-op’  she then contacted the clinic to say she was still experiencing pain at night at the injection site. The pain was only manageable with paracetamol. She attended the clinic, and I checked her sensory nerve sensations again, particularly light touch, which was normal. She described the pain as ‘burning’ and only occurred at night. She insisted that the pain was at the injection site and not around the nail area. She had started running again, approximately 5km on alternate days.

Advice and follow-up

I asked her to restrict her running to give the area a chance to settle and discussed her case with a consultant colleague. It was agreed to desensitise the area 2-3 times daily by deep massage around the injection site with standard skin cream. If possible, the mechanical massage could be supplemented with an anti-inflammatory gel when it became sore instead of paracetamol.  Products such as Ibuleve, Voltarol or Feldene were available to the patient through OTC/pharmacy sales. The patient was reassured to hear that although unusual, this was not abnormal. Because this was not an expected outcome, it had not been highlighted before the surgery commenced. Within two weeks, the patient reported no more discomfort overnight and a complete resolution to the situation. She is again training for her marathon.

Reflection

Footwear
As a keen runner, this lady appeared to have high expectations, with a rapid return to running again soon after her procedure. I did not see the trainers she used for running, but those she wore to the clinic were fine. Running footwear should have been checked as it may have exacerbated the problem. If there had been no resolution, this would have been an essential next step.

Hypodermic needle
A needle close to the phalanx can lead to discomfort, although 5 weeks is longer than usual, which is not unheard of. Post-injection neuralgia can occur, although there is little reported evidence. Most injections leave discomfort for a short period of 2 days to 2 weeks. The worst-case scenario would be a low-grade reflex pain syndrome. In Complex Regional Pain Syndrome (CRPS), the resulting pain and the initial injury do not correlate [1]

 

 

Pathogenesis

In this particular case, nerve axon (illustrated) irritation with swelling and haematoma were the most likely causes. While resolution was fairly rapid in this case, we are reminded that nerve damage can take 6-9 months to settle. Local periostitis due to the needle scraping the periosteum was also a possible cause and could have lead to bruising and sensitivity. Another possibility was a local abscess, but most likely, this would have been apparent before 5 weeks post-surgery. Additionally, infection was unlikely based on presentation, colour, swelling and low-grade discomfort. A medial-oblique and lateral x-ray of the toe would aid with this diagnosis. 

Reflection

Information is scanty on digital block injections. Säkkinen, J et al 2005 [2] points out that post injection neuralgia is rare. We can deduce that dental awareness is far greater than in podiatry.

“Paresthesia or neuralgia is usually transient, but may be permanent if anaesthetic solution is injected directly into the nerve. Therefore, injection against pressure must be avoided. Actually, it is very difficult to inject into a nerve because of the tight epineurium. Instead of that, when the needle has transfixed the lingual nerve after injection and is withdrawn through the nerve, a little amount of anaesthetic into the lumen and onto the needle can cause a chemical damage.”

Metcalfe & Riley (2010) [3] published the latest definitive book on local anaesthetic foot and ankle techniques. The authors state;

“…even with excellent technique and application of nerve stimulators, it is not always possible to avoid accidental intraneural needle placement… Whilst other techniques may result in accidental ‘needle paraesthesia’ this is quite different from deliberately setting out to create it when we know there is an increased potential for intraneural injection.”

Fortunately, my patient’s case was resolved quickly. An abscess was ruled out and would likely have shown up in a shorter time frame.  A low-grade reflex sensitivity or bruising due to periosteal irritation of the phalanx was possible.  The follow-up appointments were part of the procedural package as part of good practice. It is hoped that this case history will assist both patients and colleagues by sharing relatively poorly reported sequela in the literature. Management was maintained at a conservative level with reassurance. Discussing problems with experienced colleagues is important to ensure a proportional and balanced approach is considered. Perhaps local sensitivity is more common than we admit and remains unrecorded.


[1] Srinivasa N.Raja, Theodore S. Grabow; Complex Regional Pain Syndrome (Reflex Sympathetic Dystrophy). Anaesthesiology 2002; 96:1254-1260.
[2] Säkkinen,J, Huppunen, M, Suuronen,R Complications following local anaesthesia. Tannlegeforen Tid 2005; 115: 48–52
[3] Metcalfe, S, Reilly, I Foot and Ankle Injection Techniques. A Practical Guide. Churchill Livingstone/Elsevier.pp67-68


Thanks for reading ‘Pain after Injections for Nail Surgery’ by Alison Charlton

Published by Busypencilcase Reflective Communications Est. 2015

Submitted February 2021 and published 1st April 2021. Updated 10th June 2024.

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