- most frequent radiocarpal instability;
- the lunate is translocated ulnarly, and therefore is not supported by the radius;
- ulnar translationn is also commonly seen in disease such as RA or in Madelung's deformity;
- in RA, may occur along w/ caput ulnae syndrome;
- abnormal translation of lunate in ulnar direction is pathognomonic of ulnar translocation;
- Clinical Presentation:
- clinically the carpus and hand are offset ulnarward;
- on x-ray, lunate is positioned just distal to the ulna and a large space between the radial styloid and the scaphoid;
- two types according to position of scaphoid:
- Type I:
- entire carpus, including scaphoid, is displaced, & distance between radial styloid process & scaphoid is widened;
- Type II:
- distance between scaphoid & radial styloid process, remains normal, but the scapholunate space is widened;
- it's important to distinguish between the two types of ulnar translocation since appearance of a wide scapholunate gap may lead to the erroneous dx of scapholunate dissociation;
- late identification of ulnar translation deformity or dorsal or volar translation deformity reponds poorly to ligament repairs;
- acutely consider, radiolunate fusion;
- consider relocation of carpus & maintenance of reduction by radiolunate arthrodesis may be a more reliable and satisfactory technique;
- Darrah's Procedure:
- the main limitation with this procedure in the rheumatoid wrist, is that there is nothing to prevent continued ulnar and palmar translocation of the carpus;
- Sauve Kapandji Procedure:
- may allow a higher level of wrist function than is seen w/ the Darrah procedure
Irreducible fracture-dislocation of the distal radioulnar joint secondary to entrapment of the extensor carpi ulnaris tendon.
Congenital radio-ulnar synostosis: surgical treatment.
The Sauvé-Kapandji procedure.
Post Traumatic Ulnar Translocation of the Carpus. Rayhack JM, et al. J Hand Surg. 1987;12-A:180-189.
Original Text by Clifford R. Wheeless, III, MD.
Last updated by Data Trace Staff on Wednesday, December 12, 2012 12:23 pm