Kienbock's Disease treated with Interposition Arthroplasty using Ipsilateral Palmaris Longus Tendon and Muscle Belly.

INTRODUCTION: Kienbock's disease is an osteonecrosis of lunate bone (lunatomalacia) seen more commonly in males in the second to fourth decade of life. The exact etiology is unknown and symptoms include wrist pain and stiffness of wrist. Advanced stages of disease may require lunate excision and filling of the void by various substitutes like silicone implants, tendon grafts etc. We report a case of Kienbock's disease with lunate excision and filling of defect by coiled palmaris longus muscle and tendon unit.

CASE REPORT: An 18 year old male student presented with progressive wrist pain and difficulty in wrist movements. Investigations revealed a diagnosis of grade 4 Kienbock's disease. Lunate excision by a palmar approach followed by interposition arthroplasty with ipsilateral coiled Palmaris longus muscle belly along with the tendon was done under regional anaesthesia. Nine months post-operatively patient is pain free and wrist movements are full and free.

CONCLUSION: In advanced stages of Keinbock's disease lunate excision surgery is recommended. Post excision void can be filled with coiled Palmaris longus tendon-muscle unit together to increase the volume of the graft. This achieves snug fit, avoids the need of internal fixation, and also prevent carpal collapse. Our case shows good clinical outcome in short term with no carpal collapse by use of this procedure.