Comparison the grafts vascularization and nerve regeneration between anterior cruciate ligament reconstruction with and without remnant preservation

Abstract

Objective Establish the animal experimental models of anterior cruciate ligament (ACL) reconstruction with remnant preservation and ACL reconstruction without remnant, to investigate whether there is a difference about grafts vascularization and nerve regeneration in different reconstruction methods. Methods The 72 New Zealand rabbits were randomly divided into control group(group A), ACL reconstruction without remnant (group B), ACL reconstruction with remnant preservation (Femoral Tensioning and augmented suture)(group C) and ACL reconstruction with remnant preservation (graft passing ACL remnant sheath) (group D). At 3, 6 and 12 weeks after surgery, the graft tendon near tibial level was harvested to detect the mRNA expressions of vascular endothelial growth factor (VEGF) and growth-associated protein 43 (GAP-43) by real-time fluorescent quantitative polymerase chain reaction (FQ-PCR). Graft cell number and microvascular density (MVD)were evaluated by hematoxylin and eosin (HE) staining and immunohistochemical CD34. Results Postoperative 3, 6 and 12 weeks, VEGF mRNA relative expression in B, C, D group respectively was 1.98±0.48, 2.21±0.73, 2.06±0.14; 4.35±0.45, 3.97±0.24, 4.18±0.63; 1.14±0.62, 1.23±0.06, 1.19±0.35. compared with A group, the difference was statistically significant (P=0.000, P=0.000, P=0.026). B, C, D group had no signifcant difference (P=0.214, P=0.672, P=0.823). GAP-43 mRNA relative expression in B, C, D group respectively was 1.73±0.61, 1.58±0.12, 1.66±0.23; 5.86±1.07, 6.01±0.43, 5.76±0.74; 2.94±0.69, 3.10±0.34, 3.13±0.95. compared with A group, the difference was statistically significant (P=0.000, P=0.000, P=0.000). B, C, D group had no signifcant difference (P=0.634, P=0.138, P=0.275). At each point after operation, there was no signifcant difference in Graft cell number and MVD between B and C, D group (P=0.114, P=0.086, P=0.092; P=0.135, P=0.061, P=0.269). Conclusion Compared with ACL reconstruction without remnant, both two different ways of remnant preservation ACL reconstruction do not show obvious advantages in grafts vascularization and nerve regeneration. Key words: Anterior cruciate ligament reconstruction; Remnant preservation; Vascular endothelial growth factor; Microvessel density; Growth associated protein-43