Ulnar nerve transposition surgery is a common procedure performed to treat cubital tunnel syndrome by relieving pressure on the ulnar nerve. This condition causes numbness, tingling, and weakness in the ring and pinky fingers when the nerve is compressed at the elbow joint. The surgery involves moving the nerve from its groove behind the medial epicondyle to a new position in front of the joint, preventing it from being stretched or compressed when the elbow is bent. While often successful, patients should be aware of potential problems that can arise during recovery, ranging from expected discomfort to surgical failure.
Immediate Post-Operative Complications
Problems that occur in the first few days or weeks following ulnar nerve transposition are typically related to the surgical wound and the body’s initial reaction. Incision infection is a concern that requires immediate medical attention. Signs of infection include increasing redness, warmth spreading beyond the incision, fever, and the presence of pus or drainage.
Excessive swelling or the formation of a hematoma (a collection of blood beneath the skin) is another complication. Significant swelling or a hematoma can place pressure on the newly transposed nerve, sometimes temporarily worsening the original numbness and tingling. This must be distinguished from expected temporary nerve irritation, where mild tingling or weakness is common due to the nerve’s manipulation during surgery.
A sudden, sharp increase in pain is common when the local anesthetic nerve block wears off, often 6 to 24 hours after surgery. Postoperative pain management helps the patient manage this discomfort during early recovery. Any signs suggesting a serious problem, such as a fever persisting beyond two days or uncontrolled pain, necessitate consultation with the surgical team.
Lack of Symptom Resolution or Recurrence
The most significant concern is when original cubital tunnel symptoms remain after surgery or return later, indicating a failure of long-term decompression. A lack of symptom resolution occurs when numbness, tingling, or muscle weakness persists immediately after the operation. This is often attributed to an incomplete release of the compressed nerve during the initial surgery, meaning the nerve remains pinched.
If symptoms disappear but reappear months or years later, this is defined as recurrence. The most common cause is the formation of dense scar tissue, known as perineural fibrosis, which wraps around and compresses the transposed nerve again. This scar tissue can cause the nerve to become “tethered” or stuck in its new location, preventing the necessary gliding motion when the elbow moves.
Nerve tethering reintroduces the mechanical irritation that transposition was meant to prevent. The nerve may also become kinked or re-entrapped by a fibrous band, such as a remnant of the medial intermuscular septum. Persistent or recurrent symptoms may require a secondary surgery, often a revision neurolysis to free the nerve from the scar tissue. Revision procedures generally have a lower success rate than the initial operation.
Chronic Pain and Functional Limitations
Patients may experience long-term problems centered on the elbow joint and surrounding tissues. Persistent pain at the incision site is a common complaint, separate from the original nerve pain. This is often due to irritation or injury to smaller sensory nerves near the incision, such as the medial antebrachial cutaneous nerve, which can lead to chronic localized pain or the formation of a painful neuroma.
Elbow stiffness or a reduced range of motion is another functional limitation. The elbow is often immobilized in a splint for several weeks after surgery to allow the transposed nerve to settle. This immobilization can lead to joint capsule tightness and muscle stiffness, requiring extensive physical therapy to resolve.
If ulnar nerve compression was severe and long-standing before surgery, muscle atrophy or weakness in the hand may persist even after decompression. Nerve recovery is slow, proceeding at approximately one inch per month. If the damage was too great, the hand muscles may not fully regain their strength and bulk. In rare instances, a severe, disproportionate chronic pain condition affecting the entire limb, sometimes related to the body’s inflammatory response, can develop following the procedure.