Pronator Syndrome

Definition

 

Forearm pain caused by compression of median nerve

 

Sites of Compression

 

Pronator Teres

- commonest site

- hypertrophied / excess fascia

 

Ligament of Struthers

- remnant third head Coracobrachialis

- runs from supracondylar spur to medial epicondyle

- median nerve & brachial artery may be deep to it

 

Bicipital Aponeurosis

- lacertus Fibrosis

- from medial border of biceps to subcutaneous ulna border

- may be thickened

 

Arch of FDS

- runs from humeroulnar Head (origin CFO & Sublime tubercle medial coronoid) 

- inserts anterior oblique line on radius

- accessory muscle slips and anomalous origins of FDS

 

History

 

Pain in anteromedial EJ / volar aspect of distal arm 

- worse with repetitive pronation / supination eg tennis, tools

 

May have

- intermittent / nocturnal parasthesia

- some weakness

 

Examination

 

Tenderness at site of compression

- proximal flexors

 

Pain with resisted pronation elbow in flexion / PT

 

Other provocations test

- Ligament of Struthers - resisted flexion of elbow at 135°

- Bicipital aponeurosis - resisted supination flexed elbow 

- Arch of FDS - resisted flexion of FDS of MF

 

NCS

 

Aim

- confirm location 

- exclude CTS

 

Findings

- delayed conduction velocity across elbow 30%

- EMG abnormalities of PT or FCR

 

X-ray

 

Spur

- seen with ligament of struthers

 

MRI

 

May help identify site of compression / ligament of struthers

 

Management

 

Non-operative Management

 

NSAIDS

Avoid aggravating activities

RICE

 

Operative Management

 

Technique

 

Medial incision

- divide bicipital aponeurosis

- release pronator teres

- release FDS

- +/- ligament of struthers if present