Ulnar-Sided Wrist Pain

Take the mechanism before touching the wrist, and ask specifically about a pronated fall, a torque kickback, hypothenar impact and previous distal radius fracture.

A fall on the outstretched hand with the forearm pronated, or a torque injury from a power tool kicking back, points to a traumatic TFCC or LT tear. Insidious onset with heavy loading or a previous distal radius malunion points to ulnar impaction. Hypothenar impact points to the hook of hamate or ulnar artery. Palmer's 1989 classification is built on exactly this split — class 1 traumatic lesions are subclassified by LOCATION, class 2 degenerative lesions by SEVERITY — so the history determines which half of the classification you are in before any imaging.

Palpate the fovea, the ECU groove, the dorsal LT interval, the pisotriquetral joint and the hook of hamate as five separate points, comparing each with the other side.

Fovea = foveal TFCC or ulnotriquetral split. ECU groove = ECU pathology. LT interval dorsally = lunotriquetral injury. Pisiform = pisotriquetral joint. Hook = hamate fracture. This narrows the differential more than any single imaging test — but see the warning below on how POORLY tenderness alone discriminates, because these five points lie within about 2 cm of one another.

Test dorsopalmar translation of the ulnar head in neutral, pronation AND supination, always against the contralateral side.

Instability moves foveal TFCC tear and styloid base avulsion to the top of the list and mandates CT of both DRUJs in the same position. Rotation matters: a DRUJ that is stable in neutral can be grossly unstable at the extremes, so a single-position test misses the diagnosis.

Insist on shoulder abducted 90 degrees, elbow flexed 90 degrees, wrist neutral, no grip — then add a pronated grip view if impaction is suspected.

Positive variance supports ulnar impaction and degenerative central TFCC tear, and argues for ulnar shortening osteotomy or a wafer procedure. Negative variance raises Kienbock disease. Neutral variance with a traumatic history favours a repairable peripheral tear. GRIP ITSELF CHANGES THE MEASUREMENT: variance increased by a mean of 0.64 mm with power grip on CT, and the mechanism is PROXIMAL MIGRATION OF THE RADIUS, not distal migration of the ulna — the radiocapitellar distance shortened by an almost identical 0.62 mm.

Reproduce the clunk yourself before believing it, and record whether it hurts.

A painful snap on supination with ulnar deviation is ECU subluxation. A painful clunk on ulnar deviation from radial deviation may be midcarpal instability or LT instability. A painless clunk is usually physiological and needs no treatment — this is the commonest reason a wrist is over-investigated.

Examine the intrinsics, test Froment sign, and ask about cold intolerance and colour change before ordering any wrist imaging.

Numbness, intrinsic wasting or a positive Froment sign shifts the diagnosis to Guyon canal or cubital tunnel compression; cold intolerance and colour change shift it to ulnar artery thrombosis. Both need entirely different imaging, and a wrist MRI ordered first will delay the diagnosis rather than make it.

Ask about the other wrist, morning stiffness and other joints; look for caput ulnae and carpal translocation on the film you already have.

Bilateral symmetrical symptoms with morning stiffness and synovitis suggest inflammatory arthritis. Look for caput ulnae, erosions and carpal ulnar translocation, and request inflammatory markers and serology rather than an arthroscopy.