Hamstring tendons or patellar tendon as graft for ACL reconstruction?

Abstract

For many years the patellar tendon was regarded the ‘‘gold standard’’ for ACL reconstruction. During the last decade, the use of the semitendinosus and gracilis tendons has increased dramatically. Since most controlled studies comparing the two types of grafts show little if any difference, this is somewhat difficult to understand. It might be that this trend is ‘‘industrydriven’’. Companies earn relatively little on interference screws or endo-buttons while the new fixation devices for the hamstring reconstructions sell for much more. Laxdal and Sernert et al. from Gothenburg, Sweden now report a 2-year follow-up of a prospective comparison of hamstring and patellar tendon ACL reconstructions. It is not a randomised study but one and the same surgeon performed all 126 interventions and the patients received a standardised rehabilitation. They were followed up by a person uninformed about the purpose of the study. At 2 years they find almost no differences between the two groups. Results were very good in both groups. There seems to be a tendency to somewhat more laxity with the hamstring tendons than the patellar tendons, though. Although one of the main arguments for hamstring reconstructions has been that the patellar tendon reconstructions lead to more anterior knee pain, Laxdal and Sernert find no difference between the two groups. The only difference they find is that the patellar tendon group returns to more vigorous sports and finish with a higher Tegner score than the hamstring group. I am afraid that we still do not have the definitive answer as to what graft we should choose. In Sweden our National team of football has received almost exclusively patellar tendon grafts when they have injured their ACL. This seems reasonable when one considers the findings of the Gothenburg group. I, myself, being a patellar tendon surgeon have never really understood this shift from patellar tendon to hamstring tendons. The argument that patellar tendon reconstructions weaken the quadriceps mechanism does not really hold. Firstly, as shown by many investigations, good rehabilitation normally restores the quadriceps torque. Secondly, it is not the quadriceps that protects the ACL. It is the hamstrings! Twenty-five years ago in 1981, our group in Stockholm published a study of isokinetic torques 5–10 years after patellar tendon reconstructions (lead name is Arvidsson). We found that the good and excellent cases had good quadriceps and hamstring torques. The failures had poor torques of both muscle groups. The interesting group was the one with somewhat increased laxity after the reconstructions. They showed reduced quadriceps torques and enormously strong hamstrings. I interpret this as physiological. If your knee is not quite stable, it is better to have a somewhat reduced quadriceps torque and have very strong hamstrings, since they help defend the ACL. As some of you may know, I work part-time in Perugia, Italy since my retirement from the Karolinska in Stockholm, Sweden. Recently, Benoit, Lamontagne and Cerulli in Perugia have shown with in vivo implanted strain-gauges onto the normal ACL of normal E. Eriksson (&) Section of Sports Medicine, Karolinska Hospital, 17176 Stockholm, Sweden e-mail: eriksson.werner@telia.com