Ten patients, presenting with a 10 degrees to 25 degrees deficit of knee extension after an avulsion fracture of the anterior tibial spine, were arthroscopically treated with debridement and abrasion of the anterior spine. Notchplasty was also performed in five cases where there was a more severe deficit of extension. At follow-up (mean: 39.4 months) eight patients had recovered the full articular range of motion of the knee whereas two had a slight residual deficit of extension of between 3 degrees and 5 degrees. In no case was ligament stability compromised as compared with preoperative assessment.