Pronator teres syndrome

Background

Nerves of the left upper extremity showing the median nerve at the elbow (area of nerve copression).

• Pronator teres syndrome is considered to be the least common of the three median nerve entrapment syndromes, the other two of which carpal tunnel syndrome and anterior interosseus nerve syndrome
• Compression of the nerve occurs at the level of the elbow or at the immediate proximal portion of forearm.
• Common in the 4th and 5th decades of life
• Women have higher incidence, as well as those with forearm hypertrophy (athletes)

Clinical Features

Symptoms

• Primarily will complain of paresthesia overlying the 1st, 2nd, 3rd and lateral portion of the 4th digit
• Pain to the volar aspect of proximal forearm which may be worse on palpation
• Typically does not feature nocturnal exacerbation
• May report decreased grip strength

Physical Examination Findings

• Symptoms worsened with resisted forearm pronation, resisted elbow flexion
• Exacerbating examination techniques may produce paresthesias to volar aspect of proximal forearm, which helps distinguish from other median nerve entrapment syndromes
• May have concomitant medial epicondylitis

Differential Diagnosis

• Thoracic outlet syndrome

Elbow Diagnoses

Radiograph-Positive

• Distal humerus fracture
• Radial head fracture
  • Essex-Lopresti fracture
• Capitellum fracture
• Olecranon fracture
• Elbow dislocation

Radiograph-Negative

• Biceps tendon rupture/dislocation
• Lateral epicondylitis
• Medial epicondylitis
• Olecranon bursitis (nonseptic)
• Pronator teres syndrome
• Septic bursitis

Pediatric

• Nursemaid's elbow
• Supracondylar fracture
• Lateral epicondyle fracture
• Medial epicondyle fracture
• Olecranon fracture
• Radial head fracture
• Salter-Harris fractures

Upper extremity peripheral nerve syndromes

Median Nerve Syndromes

• Carpal tunnel syndrome
• Pronator teres syndrome
• Anterior interosseous neuropathy

Ulnar Nerve Syndromes

• Ulnar neuropathy

Radial Nerve Syndromes

• Radial neuropathy at the spiral groove (ie. "Saturday night palsy")
• Posterior interosseous neuropathy

Proximal Neuropathies

• Suprascapular neuropathy
• Long thoracic neuropathy
• Axillary neuropathy
• Spinal accessory neuropathy
• Musculocutaneous neuropathy

Other

• Brachial plexopathy
  • Parsonage-Turner syndrome
• Cervical radiculopathy

Evaluation

• Ortho appreciates dedicate elbow films at minimum
  • Usually no gross appreciable pathology
• Ultrasound and MRI also useful though not required in ED setting

Management

• Conservative management first indicated and most beneficial in large majority of cases
  • Course of extremity rest and NSAID treatment, 3-6 month management period
• Referral to orthopaedics
  • Surgical management possible if no response or worsening of symptoms over 3 month period

Disposition

• Outpatient

See Also

• Peripheral nerve syndromes