Percutaneous needle fasciotomy is a safe procedure, and nerve injuries are extremely rare. In Dupuytren’s disease, however, a so-called spiral cord can push the finger nerve out of its normal position. Because the surgeon works without direct vision, this is a particular challenge. In this video I show you a patient in whom exactly this happened, and what it meant for his treatment.
Colleagues from Denmark analysed register data on 3,331 treated fingers in 2,257 patients. They found only one case of digital nerve damage (Therkelsen et al., Acta Orthop 2020).
In my experience, one key reason is the local anaesthesia: it must not be too effective. You should still be able to feel when the needle comes close to a nerve. You then report a sharp, electric pain, and I withdraw the needle immediately. Your feedback is therefore an important part of your safety.
There is no separate “spiral nerve”. The term describes the normal digital nerve after the disease has forced it into a spiral course. The cause lies in the connective tissue, which is why hand surgeons speak of a spiral cord.
At the transition from the palm to the finger, fine connective-tissue fibres normally wind around the nerve and artery. In Dupuytren’s disease these fibres thicken and, above all, shorten. They merge into a single cord. As the cord contracts and the finger bends, it straightens and wraps the nerve and artery around itself like a rope. In the end they no longer lie safely at the side of the finger, but in the middle, directly under the skin, exactly where one would expect the hard cord. This mechanism was first described by the Canadian hand surgeon Robert McFarlane (Plast Reconstr Surg 1974).
The anatomical illustrations in the video are by my esteemed colleague Prof. Martin Langer from Münster, one of Germany’s finest hand surgeons and an internationally admired medical illustrator. Another figure is taken from the standard textbook Dupuytren’s Disease by Raoul Tubiana, Caroline Leclercq and Larry Hurst. Two Scottish surgeons have described the location found in my patient as a typical zone for this change (Macey & Thomas, J Hand Microsurg 2018).
My patient seemed an ideal candidate for needle fasciotomy. The local anaesthetic had taken effect. When the needle approached the cord, he reported marked pain. In this situation it is no longer justifiable to continue. One has to assume an irregular course of the nerve.
A few weeks later we performed conventional open surgery. The ring finger showed a flexion contracture caused by a central cord with a nodule at the base of the finger. Exactly where the needle had caused pain, we found the nerve. It was isolated and protected with a small loop so that its course could be followed safely.
First the cord was divided. Incidentally, it looked very much like a flexor tendon. This alone straightened the finger, which is exactly what the needle fasciotomy would have achieved. The diseased tissue was then removed, and both neurovascular bundles were preserved. Three Z-plasties placed in the flexion creases allowed tension-free skin closure. A plaster splint was applied for four days, after which the patient was free to move all fingers.
A spiral cord is no reason to rule out needle fasciotomy in general. It shows why experience, carefully dosed anaesthesia and your cooperation during the procedure matter so much. If an unusual nerve course becomes apparent, the treatment is changed rather than forced. If you would like an assessment of your hand, you are welcome to book a video consultation.
A German version of this article is available here: Der verflixte Spiralnerv
The darn 🐍 spiral nerve #gutlebenmitdupuytren
Gut leben mit Dupuytren 3. Mai 2020 14:17