Osseous metaplasia as a cause of loss of extension after anterior cruciate ligament reconstruction

We report a case of osseous metaplasia of an autologous anterior cruciate ligament (ACL) reconstruction that was implicated in blocking extension of the knee. Nonoperative treatment was unsuccessful. Arthroscopic excision of the ACL and osseous metaplasia abolished the fixed flexion deformity. The osseous metaplasia was an additional factor in causing the block to extension along with an anteriorly placed femoral tunnel, raising the question that nonisometry of the graft may be involved in the pathogenesis of the osseous metaplasia. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 4 (April), 2001: pp 405–407