Magnetic reasonance imaging of the surgically repaired meniscus: a 13-year follow-up study of 13 knees.

BACKGROUND

This study was initiated to evaluate the long-term outcome of meniscal sutures and to correlate clinical findings with MRI findings. We were interested to see if a clinically healed meniscus also showed as such on MRI and if degenerative changes were present

PATIENTS AND METHODS

We studied prospectively 13 patients (7 men) aged between 29 and 50 years, who had undergone closed meniscus repair between 1985 and 1988 using an inside-out technique, clinically and with MRI, with a mean follow-up time of 13 years.

RESULTS

Meniscal suture gave good clinical long-term results: all patients got a Hospital for Special Surgery score of more than 75%. In all patients the site of the previous suture was still visible on MRI, mainly from small metal artefacts in the meniscus. 4 of 7 patients with an unrepaired ACL lesion had signs of arthrosis and cartilage degeneration. MRI showed signs of mucoid degeneration or scar tissue in 6/13 of the patients.

INTERPRETATION

We believe that asymptomatic meniscal tears produce abnormal MR signals even though they have stable unions, and that MR signals at the site of repair represent edematous scar tissue, not true nonunions.