A Comparative Animal Study of Tendon Grafts Healing After Remnant-Preserving Versus Conventional Anterior Cruciate Ligament Reconstruction

Abstract

BackgroundThe aim of this study was to determine if anterior cruciate ligament (ACL) reconstruction by remnant preservation promotes cell proliferation, vascularization, proprioception recovery, and improved biomechanical properties of the tendon grafts.Material/Methods75 New Zealand rabbits were randomly assigned into the control group (group A), conventional ACL reconstruction group (group B), ACL reconstruction using remnant preservation and graft through remnant sleeve technique group (group C), and ACL reconstruction using remnant preservation and remnant tensioning technique group (group D). The remnant and healing of tendon grafts in groups C and D were observed at 3, 6, and 12 weeks after surgery, and the mRNA expression levels of VEGF, NT-3 and GAP-43 in ACL (group A) or tendon graft samples (groups B, C, and D) were determined by real-time PCR. Tendon graft cell count, microvessel density (MVD), and proprioceptors were determined by H&E staining, CD34, and S-100 immunohistochemical staining. The biomechanical properties of the tendon graft at week 12 in groups B, C, and D were examined by using a tensile strength test.ResultsRemnant and tendon grafts were not healed at 3, 6, and 12 weeks after the operation in groups C and D. VEGF, NT-3, and GAP-43 mRNA expressions in groups B, C, and D were higher than those in group A (P<0.05), but no significant difference was observed between groups B, C, and D (P>0.05). Furthermore, tendon graft cell count, MVD, proprioception, and biomechanical properties showed no significant differences (P>0.05) among groups B, C, and D at various time points.ConclusionsThere was no significant difference in cell proliferation, vascularization, proprioception recovery, or biomechanical properties of the tendon grafts between remnant-preserving and conventional ACL reconstruction methods.

The Effect of Remnant Tissue Preservation in Anatomic Double-Bundle ACL Reconstruction on Knee Stability and Graft Maturation

“…For example, preservation of ACL remnant tissue may accelerate the remodeling of grafted tendon and enhance the bone-tendon healing of the bone tunnel after ACL reconstruction. [12][13][14][15] However, some studies reported contrasting results 16,17 (►Table 1).…”

The effect of interleukin-8 in the early stage after anterior cruciate ligament reconstruction with remnant preservation

“…In previous basic animal studies, remnant tissue improved ACL graft ligamentization and graft-tunnel enlargement [2]. However, other studies showed that remnant-preserved ACLR did not improve graft ligamentization [19,25]. Therefore, the effects of remnant preservation are still controversial [21,23,24].…”

Ligamentization and Remnant Integration: Review and Analysis of Current Evidence and Implications for Scapholunate Reconstruction

“…Current ACL evidence suggests that maturation takes 9 months, although reconstructed ligaments are usually exposed to stress well before that point. 24 38 Sun et al 37 Wu et al 39 Zhang et al 40 Song of ligamentization may provide one modality for assessing healing noninvasively. 42 Second, remnant integration may offer improved proprioception compared with current reconstruction techniques, especially early in the healing process.…”

“…Unauthorized distribution is strictly prohibited. Table 3 Key findings of each study Takahashi et al 38 Sun et al 37 Wu et al 39 Zhang et al 40 Song proliferation of these proprioceptors. 38 This response may be tempered by week 24 as indicated by Song et al 36 In comparison, the sole study that evaluated proprioceptors in Achilles grafts failed to demonstrate a significant difference at any time point.…”

“…38 This response may be tempered by week 24 as indicated by Song et al 36 In comparison, the sole study that evaluated proprioceptors in Achilles grafts failed to demonstrate a significant difference at any time point. 40 This discrepancy is particularly important in the context of a study by Kim et al 45 that demonstrated a lack of mechanoreceptors in Achilles allografts used in nonremnantsparing ACL reconstructions. A further study by Chun et al 46 evaluating biopsies of Achilles allografts used in remnantsparing ACL reconstructions also reported fewer mechanoreceptors than expected.…”