We report the results of a new bone-tendon ligamentoplasty for the reconstruction of chronic injuries of the ulnar collateral ligament at the metacarpophalangeal joint of the thumb. The mean follow-up period was 36 months. Using the Glickel grading system, seven patients had excellent results and one patient had good results. The mean loss of pinch strength was 10% compared with the contralateral thumb. The mean loss of motion at the MP joint was 8%. This technique successfully restores the desired long lasting stability while maintaining mobility of the thumb's metacarpophalangeal joint.