Dobyns, James H.

A retrospective study of 45 patients with symptoms of wrist pain and weakness with clinical evidence of instability is presented. These patients had normal intrinsic interosseous ligaments demonstrated arthrographically or surgically. They were followed for a minimum of 18 months and an average of 5.8 years. All patients demonstrated instability of the proximal carpal row which is referred to as carpal instability non-dissociative (CIND). Seven patients were treated non-operatively and 38 were treated operatively. Surgical management consisted of soft tissue reconstruction directed at the area of instability in 34 cases, joint levelling osteotomy in six, three of whom also had soft tissue reconstructions, and mid-carpal fusion in one. The overall good and excellent results were a disappointing 56% and there was no significant difference between the non-surgical and surgical groups. The best results were found in the ulna-minus CIND patients who underwent a joint levelling osteotomy, with 83% good and excellent results. CIND is associatedwith extrinsic ligamentous laxity; however, significant difficulty exists in locating the precise areas of maximum pathology. This accounts for the unpredictable results of treatment. As our understanding of the pathomechanics of CIND improves, the treatment will become more specific and the results should improve.

Abstract Carpal instability can be defined as the lack of ligamentous and skeletal support adequate to maintain a wrist stable to external forces of pinch and grasp. This instability may be static or dynamic. It has been classified as (a) carpal instability, dissociated (CID), a situation in which one or more of the ligaments are torn, and (b) carpal instability, nondissociative (CIND), a situation in which the ligaments are intact but stretched. Carpal instability can also be the result of carpal bone malalignment from various causes. Arthroscopy can be particularly useful in assessing carpal instability, however arthrography with contrast medium, fluoroscopy, and stress loading should precede this arthroscopic assessment. Arthroscopy allows visualization of the volar radiocarpal and ulnocarpal ligaments of the wrist, and the arthroscopic examination can be combined with manual manipulation of the carpal bones to detect laxity of those ligaments, to examine stability of the scapholunate and lunotriquetral interosseous ligaments, and to show instability of the distal radioulnar joint.