Pes anserinus transplantation without a routine medial meniscectomy: a review of twenty-two cases.

Of 549 pes anserinus transplantations performed at the National Athletic Health Institute, Inglewood, California from 1971 through 1977, only 27 involved the transfer for anteromedial rotational instability in the presence of an intact medial meniscus. The 22 patients reviewed were evaluated with a questionnaire, physical and roentgenogram examinations, and hamstring and quadriceps muscle testing with Cybex II isokinetic dynamometer. Average length of follow-up was one year, four months. Acute anteromedial rotational instability was seen in 16 patients while six had chronic instability. All had an injury to the anterior cruciate ligament, and 12 had associated medial collateral ligament tears. One year postoperatively, 93% of the patients were participating in athletics and 70% rated their knee as above 90% of normal. The Cybex evaluation, however, revealed only 50% of the patients had 90% of normal strength in hamstrings and quadriceps. One patient developed anteromedial rotational instability, and one a torn medial meniscus, two years postsurgery. It was concluded that: I) Routine medial meniscectomy is not necessary with pes anserinus transplantation; 2) Anterolateral rotary instability does not routinely develop after pes anserinus transplantation done without medial meniscectomy; and 3) Hamstring and quadricep muscle strength below 90% of the normal extremity is not indicative of a subjective unsatisfactory functional result.Indexing terms: pes anserinus transplant; medial meniscectomy; anteromedial rotational instability; anterior cruciate ligament; and medial collateral ligament.