Treatment of Advanced Kienbock Disease With a Vascularized Radial Bone Flap Wrapped in the Pronator Quadratus

Purpose: In the present study, we aimed to assess the radiologic and clinical outcomes after excision of the lunate, insertion of a vascularized radial bone flap wrapped in the pronator quadratus, and distraction with an external fixator of the joint, for the treatment of avascular necrosis of the lunate with carpal height collapse, fragmentation, and perilunar osteoarthritic changes. Materials and Methods: From May 2006 to July 2014, a total of 25 patients (13 men and 12 women; mean age, 38.7 years; age range, 28-52 years) with advanced Kienbock disease were treated with excision of the lunate and insertion of a vascularized radial bone flap wrapped in the pronator quadratus, followed by distraction with an external fixator of the joint; all these patients met our inclusion criteria, including symptomatic avascular necrosis of the lunate with carpal collapse and osteoarthritis of the wrist. We evaluated the scaphocapitate angle for radiologic assessment. Moreover, the overall clinical results were graded by using the wrist range of motion, modified Mayo wrist score, and disabilities of the arm, shoulder, and hand score. Results: All the patients exhibited improved symptoms, and subsequently returned to their work and recreational activities. The mean scaphocapitate angles and carpal height ratio improved from 33.7 degrees (range, 32.1-35.7 degrees) and 0.46 degrees (range, 0.42-0.51 degrees) preoperatively to 56.3 degrees (range, 54.7-59.8 degrees) and 0.50 degrees (range, 0.46-0.56 degrees) at the follow-up, respectively. The final average range of motion was as follows: wrist flexion, 73 degrees (range, 62-81 degrees); and extension, 76 degrees (range, 69-88 degrees). The average postoperative modified Mayo wrist score and disabilities of the arm, shoulder, and hand score were 91 points (range, 80-100 points) and 11 points (range, 2-24 points), respectively. Conclusion: We suggest that the excision of the lunate and insertion of a vascularized radial bone flap wrapped in the pronator quadratus, followed by distraction with an external fixator of the joint, is a reliable method for the treatment of Kienbock disease with collapse or fragmentation of the lunate, and achieves high functional scores, increased range of movement, and relief of pain, without any complications.