|
Ulnar Sided Wrist Pain Anatomy
- TFCC=triangular fibrocartilage complex=articular disc, dorsal and palmer radioulnar ligaments, meniscus homologue and extensor carpi ulnaris sheath(the floor of which is called the ulnar collateral ligament)
- 82% of compressive loads are carried by radiocarpal joint, 18% by ulnocarpal joint while in neutral ulnar variance (Palmer AK, CORR 187:26;1984), positive ulnar variance increases load born by ulnocarpal joint.
- ulnar variance increases with full pronation and power grip and decreases with full suppination
Ulnar sided Wrist Pain Clincal Evaluation
- age, hand dominence, vocational and recreational demands
- compare to uninvolved side
- ROM suppination / pronation
- Identify point of maximal tenderness
- TFCC grind: deviate wrist ulnarly and apply axial load and rotation. Painful clicking that reproduces patients symptoms indicates TFCC injury.
- Shuck and lunotriquetral ballottement indicate LT injury.
- Shear test: indicates pisotriquetral arthrosis
- Assess DRUJ stability
- Assess grip strength
Ulnar Sided Wrist Pain Xray
- PA (PA=neutral pro/sup, shoulder abducted 90, elbow flexed 90, neutral wrist flex/ext); lunate should be 1/2 on ulnar border of radius, with full ulnar deviation lunate should be entirely over radius (if not suspect radiocarpal arthritis)
- lateral (shoulder adducted at side, elbow at 90, neutral sup/pro) pisiform overlies distal 1/3-1/4 of distal pole of scaphoid
- ulnar variance-measured on PA xray; line drawn perpendicular to longitudinal axis of radius at level of the subchondral bone of the palmar lip of the lunate fossa; distance the lunar head is above(positive) or below(negative)=the ulnar variance
- Clenched fist ulnar deviation view: evaluate for dynamic ulnar impingement.
- CT prone of bilateral wrists at level of Lister’s tubercle in neutral, full suppination, and full pronation useful for DRUJ subluxation/dislocation, evaluating articular surface,
- triple injection arthrography; evaluate TFCC tears; radiocarpal injection, followed by DRUJ and midcarpal injections 3 hrs later
- MRI-nearly as good as arthrography for TFCC tear. Traumatic tears seen on T2-weighted coronal images. 80% sensitivity, 100% specificity for tears. By 60 yrs old @50% of people have asymptomatic articular disc perforations. Marrow changes in the lunate, ulnar head or triquetrum indicated ulnar impaction.
|
