Pronator Teres Syndrome

Courtesy : Prof Nabile Ebraheim, University of Toledo, Ohio, USA

 

Definition:

• Pronator teres syndrome is compression of the median nerve at the level of the elbow which occurs more in women.

Course of the median nerve in the forearm:

• In the forearm, the median nerve runs between the two heads of the pronator teres muscle and then lies between the flexor digitorum superficialis and flexor digitoum profundus muscles.
• The median nerve runs down the medial side of the arm and passes 2 ½ to 4 cm below the level of the medial epicondyle before it enters between the two heads of the pronator teres.

Symptoms

• Numbness in the radial 3 1/5 fingers as well as thenar weakness (may be mistakenly attributed to carpal tunnel syndrome.)
• Dull aching pain over the proximal forearm with no night time symptoms.
• The pain is usually worsened by repetitive or forceful pronation.
• Tenderness of palpation to the pronator teres muscle.
• Sensory disturbances over the palm of the hand(Differentiates it from Carpal tunnel syndrome)

Causes of pronator teres syndrome:

 

• Most common cause is due to compression of the median nerve between the two heads of the pronator teres muscle.
• Compression due to thickening of the bicipital aponeurosis, the aponeurosis crosses from the lateral to medial over the antecubital fossa and may irritate the median nerve.
• Compression of the nerve from the fibrous arch of the origin of the flexor digitorum superficialis (FDS).

About 1% of patients have a medial supracondylar humeral spur about 5 cm proximally to the medial epicondyle.

• The ligament of Struthers is attached to this bony projection which connects the process to the medial epicondyle.
• The bony process points towards the elbow joint.
• The median nerve can become compressed by the supracondylar spur.
• The median nerve can also become trapped by the ligament of Struthers that extends from the supracondylar process to the medial epicondyle.

Treatment:

.Rest.

. Splint.

. NSAIDs.

Surgical decompression of the median nerve through all 4 or 5 possible sites of compression when non-operative management fails for 3-6 month.