The effect of cyclic knee motion on the elongation of four-strand hamstring autograft in anterior cruciate ligament reconstruction: an in-situ pilot study

Abstract

Background Pretension of the viscoelastic graft by cyclic knee motion has been confirmed to decrease the graft creep and improve the outcome of anterior cruciate ligament (ACL) reconstruction. The purpose of the present study was to investigate the effect of cyclic knee motion on the elongation of the four-strand hamstring tendon autograft in situ and to explore the stable level cycle, in which the tendon length achieved a stable level. Methods The study was performed with 53 consecutive patients undergoing transtibial ACL reconstruction with four strand hamstring tendon from Aug 2013 to Apr 2015. 43 males and 10 females were included with mean age of 29 ± 10 years. The pretension of the tendons was operated by cyclical knee motion ranging from 0 to 110°after the femoral fixation with Endo-button. The tendon length after 10, 20, 30 and 40 cycles was measured respectively and compared by repeated measure ANOVA. Then multivariate logistic regression was used to investigate the effect of the patients’ parameters (age, gender, height, body weight, tendon length, etc.) on the elongation of the graft and the stable level cycle. Results The mean lengthening of the graft at 10, 20, 30 and 40 times was 3.0 ± 1.4 mm, 4.3 ± 1.5 mm, 4.8 ± 1.7 mm and 4.8 ± 1.8 mm respectively. No significant correlation was found between the elongation and the patients’ parameters. There was significant difference of the tendon length from 0 to 30 cycles (F = 264.8, df = 1.95, p <0.001). However, the tendon length achieved a stable level after 30 cycles and the median elongation from 30 cycles to 40 cycles was 0 (0–1) mm with no significant difference (F = 2.039, p = 0.159). The male and female tendon length achieved to a stable level at 20 cycles and 30 cycles respectively but with no significant difference ( p = 0.074). Conclusions The four-strand hamstring tendon was elongated after cyclic knee motion and the elongation achieved a stable level after 30 cycles for the transtibial technique. Both of the tendon elongation and the stable level cycle were not correlated with patients’ gender, age, preoperative duration, graft diameter and length.

An Efficient Needleless Grasping Suture Technique for Graft Preparation in Anterior Cruciate Ligament Reconstruction

“…Usually, the tendon can be kept in tension by tightening the weaved sutures with bare hands or a device such as a tensioner of the INTRAFIX® ADVANCE Tibial Fastener System. The tensile force was no more than 100 N ( 14 , 15 ). After fixing the tendon at the tibial side, the extra free end and sutures need to be excised.…”

Additional tying on the adjustable-loop device improves the outcomes of anterior cruciate ligament reconstruction using hamstring autograft

“…Failure of the cortical suspensory fixation device can occur if the device breaks under pressure or if it lengthens to the point where the graft has insufficient tension to provide near‐normal ACL laxity [7]. Dynamic creep requires attention because of its association with collagenous soft tissues under sustained load and graft elongation [14, 32]. It is a key factor in mechanical failure after ACLR, indicating the importance of applying tension to the ACL graft to prevent post‐implantation graft creep [14, 27].…”

Outcomes of Tibialis Anterior Tendon Reconstruction with Autograft or Allograft

“…This complication may have occurred due to a technical error (unlikely as an experienced surgeon performed all surgeries and the operative protocol was the same) or due to graft elongation, process that was already extensively observed and reported in anterior cruciate ligament grafts. 14 Further research concerning intrasubstance changes is therefore warranted. Similarly to our results, previous case reports demonstrated good postoperative dorsiflexion with minimal loss great toe interphalangeal joint extension strength with autogenous EHL transfer.…”