Semilunar Bone Necrosis (Kienbock's Disease) - First Clinical Results after Free Microvascularised Bone Graft from the Distal Femur

Background: Idiopathic aseptic osseous necrosis of the semilunar bone is also called Kienbock's disease after Robert Kienbock who firstly described this disease. The clinical picture is characterised by a stage-like course. Internationally the classification according to Lichtman and Ross has achieved the most acceptance. The actual therapy is dependent on the present disease stage. Basically, various pressure-relieving operative procedures are possible, on the other hand operative interventions via revascularisation represent a therapeutic option. In the case of advanced disease only, "salvage procedures" like partial or total arthrodesis of the wrist are available. However, such operations are associated with marked restrictions in the range of motion and unsatisfactory clinical results. The present study reports on our clinical experiences after operative therapy for aseptic lunar bone necrosis via free microvascularised bone grafting from the distal femur. Patients and Methods: Between 01/2005 and 12/2010 nineteen patients with idiopathic semilunar bone necrosis underwent operative care via a free microvascularised bone graft from the distal femur at our institution. 16 patients could be re-evaluated retrospectively on follow-up examination at 26.5 months (range 16-42) on average after primary care. Mean age was 43.8 years (range 24-66). Clinical assessment was performed according to the Mayo wrist score (MWS) and the disabilities of the arm, shoulder and hand (DASH) score. Radiological assessment was performed according to the classification of Lichtman and Ross. Results: On operative treatment 14 patients were graded II at least according to the Lichtman classification. An additional 2 patients showed a stage III B disease. The median operative time amounted to 254 min (range 233-362). The postoperative course did not reveal any complications, in particular concerning wound healing. Only one patient (6%) showed no trabecular integration between the inserted graft and the lunar bone. Clinical evaluation according to the MWS with a median of 82.5 points (65-100), and the DASH score with a median of 29.5 points (24.2-102.2) documented good to excellent clinical results. Conclusion: Operative treatment for idiopathic semilunar bone necrosis via a free microvascularised bone graft from distal femur achieves good clinical results without an increase of postoperative complications even with advanced stages of the disease. However, long-term results and larger patient samples are required to prove the final success of this operative technique.