Semitendinosus tendon regeneration after anterior cruciate ligament reconstruction: can we use it twice?

Abstract

Purpose It has been demonstrated that the semitendinosus tendon can regenerate after being harvested in its whole length and thickness for anterior cruciate ligament (ACL) reconstruction. Ultrasound studies and guided biopsies of the regenerated tendon have shown compatibility and resembling features of the normal tendon. The question is if this neo-tendon is biologically and functionally adequate for re-use? Methods Two randomised groups of 150 volunteers were followed up for two years after harvesting the semitendinosus only (25) or the semitendinosus and gracilis tendons (25) in ACL reconstruction. The patients were followed up with clinical and ultrasound examinations, biopsies and histological tests. Surgical exploration was done in three patients for macroscopic verification. The injected arteries of four lower limbs were dissected and the tendon's arterial supplies were examined. Results Seventy-two percent of the cases showed regeneration of the semitendinosus tendons. The neotendons were inserted mostly below the knee joint (83.3 %) where they had fused with the gracilis tendon, and above the joint (60 %) when the gracilis was harvested as well. The isokinetic strength of the hamstrings and quadriceps was not significantly diminished on the operated side. A macroscopic and histological analysis of the regenerated tendons demonstrates close resemblance to normal anatomy, with focal areas of fibrosis. In one patient the regenerated tendon was used for medial patellofemoral ligament reconstruction. Conclusion The semitendinosus muscle can recover and the tendon has great potential to regenerate after harvesting for ACL reconstruction. Our data suggest that the regenerated tendons could be used for iterative ligament reconstruction.

Ultrasonography changes at quadriceps tendon donor site in anterior cruciate ligament reconstruction. Is it consistent with regeneration?

“…The data reported in these studies are conflicting (16)(17). Stevanović et al investigated regeneration at the hamstrings donor site after ACLR using clinical and ultrasound examination, biopsies and histological tests (18). The investigators demonstrated regeneration in 72% of cases.…”

Diagnosis and surgical treatment of the posterior knee instability

“…It has adequate power, it is easily taken and easily placed to adequate position. At the moment, 4-strand hamstring tendon graft is the most used graft with this surgery -it has adequate power, it is easily placed and there are no bigger complications of donor's place [35][36][37] . More important than the graft choice is the graft position, i.e.…”

Comparison of knee flexion isokinetic deficits between seated and prone positions after ACL reconstruction with hamstrings graft: Implications for rehabilitation and return to sports decisions

“…3,4 It has recently been suggested that the regenerated hamstrings tendons appear to have similar structure as the tendons in the non-harvested side. 2 Most studies that have investigated knee flexion strength recovery after ACLR with a hamstrings graft on isokinetic devices (typically in a seated position) found that there are no residual strength deficits [5][6][7][8] even though patients frequently describe perceived weakness. To explain this paradox, recent research has suggested that knee flexion strength should be measured in deep knee flexion angles where the deficits are more obvious.…”