• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Home
  • TeleConsult
  • About
  • Newsletter/Updates
  • Contact Us
  • Policies

Bone and Spine

Orthopedic health, conditions and treatment

  • General Ortho
  • Procedures
  • Spine
  • Upper Limb
  • Lower Limb
  • Pain
  • Trauma
  • Tumors

Pronator Syndrome or Pronator Teres Syndrome

By Dr Arun Pal Singh

In this article
    • Relevant Anatomy
    • Causes of Pronator Syndrome
    • Clinical Presentation
      • Provocative tests
    • Imaging
      • X-rays
      • EMG and NCV
      • Ultrasonography and MRI
    • Treatment of Pronator Syndrome
      • Nonoperative Treatment
      • Operative Treatment
      • Related

Pronator syndrome is a compressive neuropathy of the median nerve at the level of the elbow.

The median nerve, one of the three major nerves of the upper limb mainly supplies the hand and is also known as the eye of the hand.

Pronator syndrome or pronator teres syndrome results in a predominantly sensory alteration in the median nerve distribution of the hand and the palmar cutaneous distribution of the thenar eminence.

It is one the compression neuropathies of the median nerve. Other two compression neuropathies of median nerve are anterior interosseous nerve and carpal tunnel syndrome which are described separately.

Pronator syndrome is more common in women, especially in the fifth decade. It has been associated with well-developed forearm muscles as in weightlifters.

Relevant Anatomy

Anatomy of median nerve

The median nerve is formed in the axilla by the lateral and medial cords of the brachial plexus. It has contributions from has roots in C5, C6, C7, C8, and T1. In the axilla, it lies in the vicinity of the artery.

[Read more on brachial plexus]

In its course to elbow, the nerve lies close to the brachial artery, crossing it anteriorly to medially. It enters the cubical fossa lateral to the brachialis tendon.

After that, the median nerve passes between the two heads of the pronator teres. This is a possible site of compression. Further, it gives branches to the pronator teres, the flexor carpi radialis, the palmaris longus, and the flexor digitorum superficialis.

A significant branch is the anterior interosseous nerve, which is given off within the pronator teres and supplies the flexor pollicis longus, the pronator quadratus, and the lateral half of the flexor digitorum profundus.

The median nerve continues its course in the distal forearm, under the flexor digitorum superficialis, and on the flexor digitorum profundus. The palmar cutaneous branch just above the wrist and supplies the thenar eminence and central palm.

After branching, the median nerve continues into the hand via the carpal tunnel anterior and lateral to the tendons of the flexor digitorum superficialis. The carpal tunnel is formed by the carpal bones and the pronator quadratus on the inferior and side borders of the carpal tunnel. The flexor retinaculum forms the roof of the canal.

In the hand, the nerve divides into a muscular branch [supplies thenar eminence muscles] and a palmar digital branch

[supplies supply the palmar surface of the thumb, index, and middle finger and the lateral half of the ring finger, including the nail beds on the dorsal surface. – Read hand anatomy for more details]

The palmar nerves also give off branches to supply the two lateral lumbrical muscles.

Causes of Pronator Syndrome

Causes of pronator syndrome
Image Credit

Potential sites of entrapment are

  • Supracondylar process or spur [residual osseous structure on the distal humerus present in 1% of the population]
    • Bony or cartilaginous
    • On the anteromedial aspect of the humerus
    • About 5 cm proximal to the medial epicondyle
    • Often visible on x-rays
  • Ligament of Struthers [travels from tip of the supracondylar process to medial epicondyle ]
  • Bicipital aponeurosis or lacertus fibrosus
  • Between ulnar and humeral heads of pronator teres
  • Aponeurotic arch of flexor digitorum superficialis

Clinical Presentation

Aching discomfort in the forearm is the common presentation especially pain over the median nerve distribution distal to the elbow.

Weakness in the hand and paresthesia in the thumb, index, middle finger and radial half of ring finger are seen especially after repeated pronation and supination.

[Aches and sensory disturbances over the distribution of palmar cutaneous branch of the median nerve (palm of the hand) [ arises 4 to 5 cm proximal to carpal tunnel] and lack of night symptoms differentiate from carpal tunnel syndrome.]

Provocative tests

Development of paresthesia in the hand after 30 seconds or less of manual compression of the median nerve suggests pronator syndrome and may also indicate the possible site of entrapment in pronator syndrome

Provocative tests include

  • Reproduction of symptoms upon flexion of the elbow against resistance between 120° and 135°
    • Suggests ligament of Struthers compression of the median nerve
  • Resisted elbow flexion and supination while forearm is in the pronated position
    • Suggests compression at bicipital aponeurosis
  • Resisted forearm pronation with the elbow extended and wrist flexed [flexed to relax flexor digitorum superficials]
    • Suggests compression at two heads of pronator teres
  • Resisted contraction of fibrous digitorum superficialis to the middle finger
    • Compression at the flexor digitorum superficialis fibrous arch

Compression by pronator is also suggested by direct pressure on the leading edge of the pronator while the forearm is in maximum supination and the wrist in a neutral position.

Motor and sensory examination of the limb should be done as well.

Imaging

X-rays

X-rays of the elbow are done to view any bony abnormality. The supracondylar process may be visualized

EMG and NCV

Usually inconclusive

Ultrasonography and MRI

These may be useful in the evaluation. Atrophy can be appreciated in the involved muscles.

Treatment of Pronator Syndrome

Nonoperative Treatment

For mild to moderate symptom

  • Rest
  • Splinting to avoid forearm rotation
  • NSAIDS

The treatment is carried out for 3-6 months. A splint is applied to avoid forearm rotation.

Operative Treatment

It is considered when nonoperative management fails for 3-6 months. Patients who do not respond to conservative treatment and/or experience motor deficits require decompression surgery.

Surgical treatment is done by decompression of the median nerve at possible sites of compression

Compression points are determined by physical examination in preoperative assessment.

The incision begins a few centimeters above the elbow crease at the antecubital fossa and continues distally in an S or zigzag fashion.

The bicipital aponeurosis should always be divided. The median nerve is then exposed by dividing the superficial fibers of the pronator teres where the areas of compression are addressed individually.

A  soft dressing is used postoperatively. Elbow is Splinting, however, is done by keeping the elbow slightly flexed and the wrist in a neutral position.

The sutures are removed 12-14 days after carpal tunnel release. Patients are allowed activity without restrictions after 6-8 weeks

Outcomes of surgical decompression are variable. About 80% of patients have relief of symptoms.

Related

Spread the Knowledge
 
     

Filed Under: Hand and Upper Limb

About Dr Arun Pal Singh

Arun Pal Singh is an orthopedic and trauma surgeon, founder and chief editor of this website. He works in Kanwar Bone and Spine Clinic, Dasuya, Hoshiarpur, Punjab.

This website is an effort to educate and support people and medical personnel on orthopedic issues and musculoskeletal health.

You can follow him on Facebook, Linkedin and Twitter

Primary Sidebar

Browse Articles

L3 Compression Fracture

Thoracolumbar Spine Injuries Presentation and Treatment

Thoracolumbar spine injuries refer to injuries of the thoracic and lumbar spine. Thoracic spine has 12 vertebrae from T1 to T12 whereas lumbar vertebrae are five in number are mostly caused by two-wheeler accidents. Injuries to both these regions are considered together because the pattern of injury and their treatment is similar. Thoracolumbar spine injuries are […]

radioscapholunate arthrodesis

Radioscapholunate Arthrodesis – Indications and Procedure

Radioscapholunate arthrodesis is a type of partial arthrodesis of the wrist which preserves some of the motion in the wrist joint. It is based on the observation that most activities of daily living can be accomplished with wrist motion in the range of 10° flexion, 35° extension, 10° radial deviation, and 15° ulnar deviation. Wrist […]

Gull wing deformity erosive osteoarthritis

Erosive Osteoarthritis Causes and Treatment

An erosive osteoarthritis is a form of osteoarthritis with additional erosive or inflammatory phenomena though the patients are negative for rheumatoid factor negative. It most commonly affects the distal and proximal interphalangeal joints of the hand. The first carpometacarpal joint is affected less frequently. Joints of the foot are affected less commonly. Joints such as […]

Patella ligament stabilizers

Patellar Instability – Causes, Presentation and Treatment

Patellar instability or Patellofemoral instability is a frequent cause of symptoms of anterior knee pain and episodes of mechanical instability. It is also called patellar subluxation syndrome. There is a difference between symptoms of instability and patellar dislocation, though the former may cause the latter to happen. The term can denote a sign on physical examination or […]

CT of Osteoid Osteoma

Osteoid Osteoma Diagnosis and Treatment

Osteoid osteoma is a painful benign bone lesion most often seen in the adolescent age group. The lesion consists of osteoblastic or growing cell mass called a nidus surrounded by a zone of sclerotic but normal bone. The lesion is generally small and often less than 2 cm in diameter. Osteoid osteoma accounting for 5% […]

Periprosthetic Fracture Femur in a patient who had undergone bipolar hemiarthroplasy previously for fracture of neck of femur

Hip Injuries Xrays and Photographs

Hip injuries consist of injuries to the acetabulum, lower pelvis, intertrochanteric fractures, fracture of neck of femur, fracture of the femoral head, subtrochanteric fractures and hip dislocations. A collection of x-rays and clinical photographs of hip injuries is being presented. Image 1 –  Xray of Oblique Subtrochanteric Fracture of Femur With Dynamic Hip Screw and […]

An Above knee cast in patient of fracture tibia

Types of Plaster Casts and Their Use

There are many types of plaster casts used in the treatment of fractures and other ailments. Here are the major types of casts. Types of  Plaster Casts in Upper Extremity Long arm Cast long arm cast encases the arm from the hand to about lower two-thirds of the arm till a level below the armpit, […]

© Copyright: BoneAndSpine.com
Manage Cookie Consent
The site uses cookies. Please accept cookies for a better visiting experience.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage vendors Read more about these purposes
View preferences
{title} {title} {title}
 

Loading Comments...