Association between the capitate-triquetrum distance and carpal collapse in static scapholunate instability

Long-standing scapholunate instability frequently leads to progressive deterioration of the adjacent joint cartilages in a consistent repetitive sequence of arthritis. The purpose of this study was to investigate whether the capitate-triquetrum distance is related with the occurrence of carpal collapse in cases of static scapholunate instability. In this retrospective study, 41 patients formed two groups based on the capitate-triquetrum distance; twenty-four with distance of less than 5mm and 17 with distance of 5mm or more. No significant difference was detected with respect to age, sex distribution, dominant hand involvement, initial treatment and time from injury to final x-rays. Three patients (3/24, 12.5%) of the C-T < 5mm group and 10 patients (10/17, 58.8%) of the C-T ≥ 5mm group had no sign of carpal collapse. This difference was statistically significant (p=0.017). Capitate-triquetrum distance could reliably contribute in the decision making process in difficult cases of static scapholunate instability.