Incidence of scapholunate ligament dissociation in patients with aspiration-confirmed gout.

Purpose: To determine the incidence of scapholunate (SL) dissociation in patients with aspiration-confirmed gout of the wrist and aspiration-confirmed gout in any joint excluding the wrist.

Methods: Geisinger Medical Center uses the EPIC electronic medical record system, which maintains International Classification of Diseases, 9th Revision, Clinical Modification and Current Procedural Terminology coding information for every patient encounter in our hospital system. We queried this electronic medical record system from 1998 to 2008 using the International Classification of Diseases, 9th Revision, Clinical Modification codes for gout as well as Current Procedural Terminology codes for aspiration of a minor, intermediate, or major joint. We then evaluated medical records of patients meeting criteria for the presence of wrist x-rays. We examined x-rays for SL interval, SL angle, and capitolunate angle and determined the incidence of SL dissociation in all patients with a diagnosis of gout confirmed by joint aspiration.

Results: We reviewed a total of 1,105 cases; 159 patients met inclusion criteria. Of 159 patients, 20 had aspiration-confirmed gout in the wrist. We determined incidence using 2 definitions: (1) one or more positive radiographic criteria for SL dissociation, and (2) two or more positive radiographic criteria. The incidence of SL dissociation in wrists with aspiration-confirmed gout was 60% by definition 1 and 25% by definition 2. The average SL interval was 2.95 mm. The remaining 139 patients had aspiration-confirmed gout in joints other than the wrist. A total of 69 patients had 1 or more positive criteria for SL dissociation, whereas 18 had 2 or more positive criteria, making the incidence of SL dissociation 49.6% and 12.9%, respectively. The average scapholunate interval was 2.28 mm. The incidence of SL dissociation in patients with aspiration-confirmed gout in any joint was 50.9% and 14.5%, based on the above definitions.

Conclusions: This study establishes the incidence of SL dissociation in patients with gouty arthropathy of the wrist as 60% and 25%, respectively, based on the above definitions. In addition, our study suggests that, as a result of the systemic nature of gout, a patient with aspiration-confirmed gout at a joint remote from the wrist might have subclinical effects in the wrist, leading to SL dissociation over time.

Type Of Study/level Of Evidence: Prognostic IV.