INTRODUCTION: This study examines Isolated Lunotriquetral Interosseous Ligament Tears treated by Ulnar Shortening Osteotomy(USO) and variables related to the diagnosis. METHODS: 63 patients not responding to conservative management of ulnar sided wrist pain (wrist x-rays and splinting) underwent bone scan, arthrogram and arthroscopy to confirm the presence of an isolated lunotriquetral interosseous ligament tear. All were treated with USO; in most cases, 2.5mm of ulna was removed. RESULTS: Pre-op ulnar variance was positive in 44, neutral in 13, negative in 6. Mean pre-op grip strength increased from 52 lbs. to a mean post-op strength of 69 lbs. Mean bone healing time was 17 weeks post osteotomy. There were no non-unions or complications. Variables having a high degree of association with LTL tears are; mechanism of injury and positive ulnar variance, also ulna sided wrist pain radiating to the ring and little fingers. A loaded dorsiflexion wrist injury was the greatest precipitating injury, commonly seen with MVA’s. Follow-up was completed in 53 patients post-USO. Results were graded using Chun and Palmers revised grading system: 21 excellent, 23 good, 9 fair and no poor outcomes. CONCLUSION: This study demonstrates USO to be an effective form of treatment for isolated interosseous lunotriquetral ligament tears. Ulnar shortening is not effective when L-T tears are accompanied by a mid carpal instability or lunotriquetral osteoarthritis. The surgeon should maintain a high degree of suspicion for LT ligament tears when treating patients with ulnar sided wrist pain following an MVA or dorsiflexion injury, particularly when accompanied by ulnar positive variants.