[Local anesthesia of the finger through the flexor tendon sheath]

A series of 350 cases of local anaesthesia of the finger using the flexor tendon sheath is reported. The patients were ranked ASA 1 or 2 and the youngest was 12 months old. This technique was used for day case surgery, such as nail trauma and tumours, wound exploration, tumour and cyst removal, tenolysis and neurolysis. The needle was inserted on the palmar aspect of the metacarpophalangeal joint, into the digital flexor tendon of the corresponding finger. Thereafter the needle was withdrawn very slightly in order to inject the local anaesthesia solution within the sheath, and not the tendon. The volumes were respectively 1 ml in children and 3 to 4 ml in adults of either 2% lignocaine or 0.5% bupivacaine without adrenaline. As palmar injections are painful a freezing spray solution was used prior to insertion of the needle. There was no anaesthesia of the dorsal digital nerves, as opposed to the findings of the author of the first series. This technique, which can be qualified as being easy and reliable, could be a valuable alternative for the ring or interdigital blocks, which carry a significant risk of vascular and neurological complications.