Radiolunate arthrodesis (RLA) has become an established surgical technique for stabilising wrists destroyed by RA. Our modified surgical technique with special osteosynthesis material has enabled the spectrum of indications to be expanded to include stage IV a--sagittal instability.
44 radiolunate arthrodeses were carried out from 10.96 to 6.98. 19 (43.2%) satisfied the criteria for correction RLA with correction of sagittal instability. All (100%) of the 19 radiolunate arthrodeses were included in a follow-up examination, and all were examined clinically and radiologically at specified intervals. The mean follow-up is 22.8 months.
Correction of the lunate drift in the sagittal plane was successful. The radiolunate angle was reduced from a mean 23.7 degrees before surgery to 9.3 degrees afterwards. The lunate drift in the frontal plane, which is shown by the ulnar translation index (UTI) was corrected from an average of 0.35 before surgery to 0.30 afterwards. Restoration of the carpal height by bone grafting from a mean preoperative CHI of 0.47 to 0.50 after surgery was achieved. We discovered one failure, thus the consolidation rate dropped to 94.7%.
Since the capitate is the centre of rotation and movement at the wrist, a stable central pivot is essential, and correction of sagittal instability is particularly important. This demand can also be met by our modified radiolunate arthrodesis.