Biomechanical evaluation of a novel transtibial posterior cruciate ligament reconstruction using high-strength sutures in a porcine bone model.

BACKGROUND: Multiple techniques are commonly used for posterior cruciate ligament (PCL) reconstruction. However, the optimum method regarding the fixation of PCL reconstruction after PCL tears remains debatable. The purpose of this study was to compare the biomechanical properties among three different tibial fixation procedures for transtibial single-bundle PCL reconstruction. METHODS: Thirty-six porcine tibias and porcine extensor tendons were randomized into three fixation study groups: the interference screw fixation (IS) group, the transtibial tubercle fixation (TTF) group, and TTF + IS group (n = 12 in each group). The structural properties of the three fixation groups were tested under cyclic loading and load-to-failure. The slippage after the cyclic loading test and the stiffness and ultimate failure load after load-to-failure testing were recorded. RESULTS: After 1000 cycles of cyclic testing, no significant difference was observed in graft slippage among the three groups. For load-to-failure testing, the TTF + IS group showed a higher ultimate failure load than the TTF group and the IS group (876.34 ±â€Š58.78 N vs. 660.92 ±â€Š77.74 N [P < 0.001] vs. 556.49 ±â€Š65.33 N [P < 0.001]). The stiffness in the TTF group was significantly lower than that in the IS group and the TTF + IS group (92.77 ±â€Š20.16 N/mm in the TTF group vs. 120.27 ±â€Š15.66 N/m in the IS group [P = 0.001] and 131.79 ±â€Š17.95 N/mm in the TTF + IS group [P < 0.001]). No significant difference in the mean stiffness was found between the IS group and the TTF + IS group (P = 0.127). CONCLUSIONS: In this biomechanical study, supplementary fixation with transtibial tubercle sutures increased the ultimate failure load during load-to-failure testing for PCL reconstruction.

[Biomechanical research of anterior cruciate ligament fixation by tibial interfacial screw combined with bone tunnel crossing technology].

OBJECTIVE: To compare the strength difference between the interfacial screw and the interfacial screw combined with bone tunnel crossing technology to fix the tibial end of ligament during anterior cruciate ligament (ACL) reconstruction through the biomechanical test. METHODS: Twenty fresh frozen pig tibia were randomly divided into two groups ( n=10) to prepare ACL reconstruction models. The graft tendons in the experimental group were fixed with interfacial screw combined with bone tunnel crossing technology, and the graft tendons in the control group were fixed with interfacial screw. The two groups of specimens were fixed in the high-frequency dynamic mechanics test system M-3000, and the length change (displacement), ultimate load, and stiffness of graft tendons were measured through the reciprocating test and load-failure test. RESULTS: The results of reciprocating test showed that the displacement of the experimental group was (3.06±0.58) mm, and that of the control group was (2.82±0.46) mm, and there was no significant difference between the two groups ( t=0.641, P=0.529). The load-failure test results showed that the stiffness of the experimental group and the control group were (95.39±13.63) and (91.38±14.28) N/mm, respectively, with no significant difference ( t=1.021, P=0.321). The ultimate load of the experimental group was (743.15±173.96) N, which was significantly higher than that of the control group (574.70±74.43) N ( t=2.648, P=0.016). CONCLUSION: In ACL reconstruction, the fixation strength of tibial end with interface screw combined with bone tunnel crossing technology is obviously better than that of interface screw alone.

[Effectiveness of a novel remnant-preserving anterior cruciate ligament reconstruction with bidirectional barbed suture].

Objective: To investigate the feasibility and effectiveness of a novel remnant-preserving anterior cruciate ligament (ACL) reconstruction with bidirectional barbed suture. Methods: Between February 2014 and January 2016, 96 patients (96 knees) with ACL injury who met the inclusion criteria were recruited and randomly divided into 2 groups ( n=48). All patients underwent ACL reconstruction with autologous tendon. The tibial remnant was fixed with PDS-Ⅱ suture (control group) and bidirectional barbed suture (trial group). There was no significant difference in age, gender, injury side, the interval from injury to operation, and preoperative knee stability (KT-1000 test), International Knee Documentation Committee (IKDC) score, and Lysholm score ( P>0.05). The knee stability (KT-1000 test), IKDC score, Lysholm score, proprioception, and Cyclops lesion after operation were recorded. Results: All incisions healed by first intention in both groups. Forty-four patients in control group were followed up 26-47 months (mean, 36.6 months), and 45 patients in trial group were followed up 26-48 months (mean, 35.6 months). At last follow-up, the IKDC score, Lysholm score, and KT-1000 test were significantly improved when compared with preoperative ones in both groups ( P<0.05); but no significant difference was found between 2 groups ( P>0.05). There was no significant difference in proprioception between 2 groups at 1 and 2 years after operation, and between 1 year after operation and 2 years after operation ( P>0.05) in the same group. The incidences of Cyclops lesion at 6 months, 1 year and 2 years after operation were 0, 4.44% (2/45), and 4.44% (2/45) in trial group, and 13.6% (6/44), 13.6% (6/44), 20.5% (9/44) in control group, showing significant differences between 2 groups at 6 months and at 2 years after operation ( P=0.012; P=0.022) and no significant difference at 1 year after operation ( P=0.157). Conclusion: The remnant-preserving ACL reconstruction with bidirectional barbed suture can decrease the incidence of Cyclops lesions. However, this technique can not improve the effectiveness in terms of the clinical function and stability compared with the traditional technique.