Finger flexor and extensor tendon lacerations & finger nerve lacerations
I cut my hand / finger and can’t move my finger - I lost sensation in a part of my hand
Fingers are a construct out of three bones and the thumb out of two bones which are called ‘phalangeal bones’. In between these are joints which allow for flexion and extension. The actual motion is generated by muscles in the forearm which are connected to long tendons that terminate in the finger and thumb tip. There are two flexor tendons for each finger (superficial and deep flexor) and one flexor tendon for the thumb on the palmar side and one extensor tendon / mechanism for each finger and thumb. Next to the flexor tendon on each side there is finger nerve. The close proximity of the tendons and nerves to the skin makes them prone to lacerations.
What are the symptoms of finger tendon / finger nerve laceration?
In most cases a deep penetrating skin laceration is followed by inability to fully flex or extend a finger or thumb. Since finger nerves are adjacent on each side of the flexors tendons they are frequently part of the injury and result in numbness in their field of innervation.
Who gets a finger tendon & nerve laceration?
Deep penetrating skin lacerations can cut one or more tendons. A well known injury is the ‘Avocado hand’ where tendon lacerations occur whilst preparing an Avocado. Every profession that works with knifes or sharp tools is exposed to tendon lacerations. Some blunt trauma incidents such as crush injuries can also result in tendon laceration and there is also the ‘Rugger Jersey finger’ as a sports injury which is an avulsion of the flexor tendon insertion with or without a bony fragment.
How are finger tendon & nerve lacerations diagnosed?
The location of a penetrating skin injury in combination with inability to flex or extend a finger or thumb is a firm indication of tendon laceration. Due to the finger nerves being located directly next to the flexor tendons these are often also cut and result in numbness in their field of innervation. That might only be one half of a finger or thumb.
Treatment for finger tendon & nerve laceration
Partial lacerations of tendons up to 50% of their diameter can be treated non operative. In cases where the tendon is fully cut, the muscle belly will retract the tendon and surgical repair is mandatory to restore function. If surgery is delayed in full tendon transections a 2-stage-approach and tendon grafting might be be necessary. If a nerve is cut, microsurgical repair using magnification loupes or microscope is required.
Surgery for finger tendon & nerve laceration
Surgery for for finger tendons and nerves require the skill set of microsurgery where loupe magnification and use of a theatre microscope allow for accurate repair of these delicate structures. Depending on the amount of surgery or structures needing repair these procedures can be carried out as day surgery or as one over night stay.
Preparing for surgery for finger tendon & nerve laceration
If required we will also arrange for a bulk billed pre-admission clinic at the hospital. This is run by a specialist anaesthetist who will gather information and request investigations that are required for safe anaesthesia. Our reception staff will advise of costs, hospital and admission details. Often these surgeries are carried out as emergency surgery and we will endeavour to provide as much information as possible prior to the procedure.
Recovery from surgery for finger tendon & nerve laceration
To protect the repair of tendons and nerves brace immobilisation is required for roughly six weeks. However since tendons are gliding structures early hand therapy for range of motion exercises is important in order to avoid adhesions and scarring. Whilst tendon function is restored at the six to eight week mark after surgery, recovery of nerves takes a longer term until sensation returns. As a rule of thumb one can measure the distance from the site of nerve laceration to the finger tip. The amount of millimetres is equivalent to the number of days it will take to have some sensation restored.