Summary

This study evaluates the impact of tape-reinforced suturing of the tendon ends on the structural integrity of hamstring grafts in all-inside ACL reconstruction, finding that it significantly enhances force maintenance, reduces elongation, and increases stiffness and load to failure compared to standard grafts.

Abstract

Background

All-inside anterior cruciate ligament reconstruction (ACLR) is an emerging technique for treating ACL injuries. The standard all-inside techniques use a 4- or 6-stranded graft configuration with the tendon looped over the adjustable loop devices (ALD) and the inner graft limbs placed inside the construct and secured with circumferential stitches. The latest generation of ALD offers additional tape reinforcement for inner graft limbs to secure them directly to the ALD. Currently, there is a lack of data comparing the primary fixation of tape-reinforced grafts to conventionally prepared grafts in the clinic.

Purpose

This study aims to evaluate the effect of tape-reinforced suturing of the free inner graft limbs in a hamstring graft on elongation, stiffness, and load to failure compared to standard clinical grafts in all-inside ACLR. We hypothesized that tape-reinforced suturing would enhance the overall structural integrity of the graft and result in reduced elongation, increased stiffness, and higher load to failure compared to unreinforced grafts.
Study Design:
Controlled laboratory study.

Methods

Human hamstring tendons (n = 32) were prepared in four different configurations (n = 8 per group): four- and six-strand configurations with and without tape-reinforced suturing of the inner free tendon ends. Each specimen was preconditioned and tested under three different loading conditions (1000 cycles of position-controlled loading and 1000 cycles each between 10-250 N and 10-400 N in force-controlled mode), followed by a pull to failure (50 mm/min). Force maintenance, dynamic and total elongation, stiffness, and ultimate failure load were evaluated. Differences between graft preparation techniques were analyzed using a one-way analysis of variance (ANOVA) with Tukey post-hoc test (p < .05).

Results

The force maintenance was significantly higher (p < 0.001) in the tape-reinforced groups than in the standard groups, with the tape-reinforced four- and six-strand configurations showing a significant increase in force maintenance of 8 % and 11 % compared to their counterparts, respectively. No significant difference was found in initial elongation between the four groups. However, the tape-reinforced groups showed significantly lower (p < 0.001) dynamic elongation after the 250 N load block (quadrupled: 0.89 ± 0.13 mm vs. 1.59 ± 0.21 mm, 6-strand: 0.99 ± 0.09 mm vs. 1.67 ± 0.16 mm) and 400 N load block (quadrupled: 3.15 ± 0.49 mm vs. 4.44 ± 0.31 mm, six strand: 2.65 ± 0.26 mm vs. 4.22 ± 0.65 mm) compared to non reinforced grafts. Initial and final stiffness were also significantly higher (p ≤ 0.036) in the tape-reinforced groups for 250 N and 400 N load blocks. Ultimate load to failure was significantly higher (p ≤ 0.003) in the six-strand tape-reinforced group compared to other groups.

Conclusion

All-inside ACLR with tape-reinforced suturing of the free hamstring tendon ends resulted in significantly reduced tension loss and cyclic elongation to reduce knee laxity with adjustable graft fixation.
Clinical Relevance:
An alternative four- and six-strand graft preparation technique for all-inside ACLR with tape-reinforced suturing of inner graft limbs provided higher construct stability compared to conventional grafts, but the overall clinical significance on healing rates remains unclear.