Kienbock's disease causes destruction of the central wrist bone called the lunate. In this article, the authors followed 11 patients with Kienbock disease who underwent total lunate arthroplasty. The technique described here replaces the diseased lunate with an artificial one made of titanium. They followed the patients for a mean of 11 years after surgery. At final followup, no patient had required a revision surgery. 2 out of 11 implants had dislocated dorsally. Visual analog pain scale averaged 0.5 at rest and 0.3 at night. It was 2.7 during heavy exertion. Dash score averaged 9.6 at final followup.
Comment:
This is an honest study with long term follow up on a rare treatment for a fairly rare disease. The results are modest, given the 20% dislocation rate. However, the high function of the patients and low overall disability scores demonstrates that this is a viable option for some patients. In general, I prefer to perform proximal row carpectomy in stage 3B Kienbock's disease. These authors assert that performing a lunate replacement does not burn any bridges since the proximal row carpectomy can always be done later. I'm not sure if that's true. At least one of the x-rays in the study show interval development of arthritis in the wrist after lunate arthroplasty.
Conclusion:
In stage 3B Kienbock disease, lunate arthroplasty may be a viable option. However, the complication rate is high. Proximal row carpectomy may be just as effective with a lower complication rate.
