Abstract
Background Kienböck's disease leading to progressive carpal collapse alters the wrist biomechanics leading to early arthritis and degenerative changes. Out of multiple surgical procedures present, no gold standard has been described. Scaphocapitate arthrodesis (SCA) is limited carpal fusion which shifts the loading axis toward radioscaphoid joint. This study presents the midterm clinical and radiological results of SCA in Kienböck's disease.
Materials and Methods The data were reviewed from January 2016 to December 2017. Lichtman's classification used to stage the disease. Clinical variables were noted for wrist range of motion, grip strength, visual analog scale (VAS) score, quick disabilities of the arm, shoulder, and hand (quickDASH), and patient-rated wrist evaluation (PRWE) scores. Radiographs were evaluated for union, ulnar variance, carpal height ratio, radioscaphoid angle, and scapholunate angle.
Results A total of 11 patients of Stage IIIA and IIIB Kienböck's disease with mean age of 24 years were included in the study with a minimum of 18 months of clinical follow-up. The procedure resulted in decreased ranges of motion but improved grip strength (26.09 ± 4.76 from 19.54 ± 4.63 kgf) and reduced pain with VAS score decreased from 7.36 ± 0.8 to 2 ± 1. Radiographic analysis showed union in all patients, reduced carpal height with a corrected radioscaphoid angle (from 62.12 to 48.3 degrees), and scapholunate angle (from 34 to 26.27 degrees).
Discussion SCA has advantage of technical ease of orientation of the scaphoid and osteosynthesis of only one intercarpal joint with a large contact surface. Coupling the distal and proximal carpal rows results in significant loss of mean wrist range of motion but with improved grip strength, shifting the load away from the radiolunate joint. However, long-term studies are needed for clinical benefits and radiographic signs of radioscaphoid arthritis for the treatment of advanced-stage Kienböck's disease.
Level of Evidence This is a Level IV, retrospective observational study.
Keywords
lunate - osteonecrosis - avascular necrosis - Kienböck's disease - scaphocapitate arthrodesis
