Flexor carpi radialis tendinopathy

Flexor carpi radialis (FCR) tendinopathy presents with pain in the volar radial wrist. It usually develops due to chronic overuse, particularly in areas of the tendon that are exposed to rough surfaces (e.g. osteophytes).

Epidemiology

Flexor carpi radialis tendinopathy is a rare condition that often affects athletes, especially those who play golf, racquet sports, volleyball, or water polo ¹.

Clinical presentation

Patients typically present with pain over the volar radial aspect of the wrist. On physical examination, tenderness over the volar radial forearm along the FCR tendon at the distal wrist flexion crease is seen. Resisted wrist flexion and resisted radial wrist deviation will trigger pain.

Pathology

Numerous pathologies can affect the FCR tendon including ^2-4:

• primary (flexor carpi radialis tunnel syndrome): stenosing tenosynovitis within the FCR tunnel

• secondary

  • scaphoid fracture

  • scaphoid cysts

  • distal radius fracture

  • scaphotrapeziotrapezoidal (STT) joint arthritis

  • first carpometacarpal joint arthritis

The FCR tendon is enveloped by a sheath from its musculotendinous origin to the trapezium. It passes through a fibro-osseous tunnel where it is vulnerable to narrowing, tendinopathy, and tearing.

Although the FCR tendon is less likely to get constricted within the space of its sheath near the fibro-osseous tunnel, it is more susceptible to mechanical irritation caused by osteophytes.

Radiographic features

Plain radiograph

In cases of primary tendinopathy, x-rays show no significant abnormalities.

Secondary tendinopathy may be associated with healed scaphoid or distal radius fractures, STT arthritis or exostosis, or first carpometacarpal arthritis.

MRI

FCR tendinopathy is best seen on T2WI and displays an increased signal around the FCR sheath. Associated conditions of secondary tendinopathy including ganglion cyst and scaphoid cyst may be seen.

Treatment and prognosis

A non-operative approach is the first line of treatment and includes immobilization, nonsteroidal anti-inflammatory drugs and steroid injections.

The operative approach includes surgical release of the FCR tendon sheath and can be effective in refractory cases ^5,6.

Differential diagnosis

Other causes of radial-sided wrist pain should be considered such as:

• first carpometacarpal or STT arthritis 

• scaphoid cyst

• ganglion cyst

• De Quervain tenosynovitis

• carpal tunnel syndrome