ObjectiveTo observe the effect of preserving tibial residual fibers on the expressions of ligament remodeling related genes in rabbit anterior cruciate ligament (ACL) reconstruction model.
MethodsSixty healthy adult New Zealand white rabbits were randomly divided into 4 groups:normal control group (group A, n=6) , sham-operation group (group B, n=18) , non tibial remnant preserved group (group C, n=18) , and tibial remnant preserved group (group D, n=18) . At 2, 6, and 12 weeks after operation, the ligament tissue was harvested to detect the mRNA expressions of collagen type 1A1(COL1A1) , collagen type 3A1(COL3A1) , transforming growth factor β1(TGF-β1), vascular endothelial growth factor (VEGF), growth-associated protein 43(GAP-43) , and neurotrophin 3(NT-3) by real-time fluorescent quantitative PCR.
ResultsAt each time point, there was no significant difference in the mRNA expressions of COL1A1, COL3A1, VEGF, and NT-3 between group A and group B (P>0.05) . In group D, the mRNA expressions of COL1A1, COL3A1, TGF-β1, and GAP-43 significantly increased when compared with those of group C at 6 weeks after operation (P＜0.05) ; an increased level of VEGF mRNA was also detected in the group D at 12 weeks after operation (P＜0.05) ; and an increased level of NT-3 mRNA was also observed in group D at 2 and 12 weeks after operation (P＜0.05) .
ConclusionThere is a time-dependent manner of angiogenesis-promoting, repair-related, and nerve-related gene expressions after ACL reconstruction with preserving tibial residual fibers during the process of ligamentization. Furthermore, the remnant preservation in ACL reconstruction can promote the expressions of related genes in some time points.
ObjectiveTo investigate the feasibility and effectiveness of a novel remnant-preserving anterior cruciate ligament (ACL) reconstruction with bidirectional barbed suture.MethodsBetween 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.ResultsAll 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).ConclusionThe 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.
ObjectiveTo prepare the small intestinal submucosa (SIS)-silk composite scaffold for anterior cruciate ligament (ACL) reconstruction, and to evaluate its properties of biomechanics, biocompatibility, and the influence on synovial fluid leaking into tibia tunnel so as to provide a better choice in the clinical application of ACL reconstruction.
MethodsThe silk was used to remove sericin and then weaved as silk scaffold, which was surrounded cylindrically by SIS to prepare a composite scaffold. The property of biomechanics was evaluated by biomechanical testing system. The cell biocompatibility of scaffolds was evaluated by live/dead staining and the cell counting kit 8 (CCK- 8). Thirty 6-week-old Sprague Dawley rats were randomly assigned to 2 groups (n=15). The silk scaffold (S group) and composite scaffold (SS group) were subcutaneously implanted. At 2, 4, and 8 weeks after implanted, the specimen were harvested for HE staining to observe the biocompatibility. Another 20 28-week-old New Zealand white rabbits were randomly assigned to the S group and SS group (n=20), and the silk scaffold and composite scaffold were used for ACL reconstruction respectively in 2 groups. Furthermore, a bone window was made on the tibia tunnel. At last, the electric resistance of tendon graft in the bone window was measured and recorded at different time points after 5 mL of 10% NaCl or 5 mL of ink solution was irrigated into the joint cavity recspectively.
ResultsThe gross observation showed that the composite scaffold consisted of the helical silk bundle inside which was surrounded by SIS. The maximal load of silk scaffold and composite scaffold was respectively (138.62±11.41) N and (137.05±16.95) N, showing no significant difference (P>0.05); the stiffness was respectively (24.65±2.62) N/mm and (24.21±2.39) N/mm, showing no significant difference (P>0.05). The live/dead staining showed that the cells had good activity on both scaffolds. However, the cells on the composite scaffold had better extensibility. In addition, the cell proliferation curve indicated that no significant difference in the absorbance (A) values was founded between groups at various time points (P>0.05). HE staining showed less inflammatory cells and much more angiogenesis in SS group than in S group at 2, 4, and 8 weeks after subcutaneously implanted (P<0.05), indicating good biocompatibility. Additionally, the starting time points of electric resistance decrease and the ink leakage were both significantly later in SS group than in S group (P<0.05). The duration of ink leakage was significantly longer in SS group than in S group (P<0.05).
ConclusionThe SIS-silk composite scaffold has excellent biomechanical properties and biocompatibility and early vacularization after in vivo implantation. Moreover, it can reducing the leakage of synovial fluid into tibia tunnel at the early stage of ACL reconstruction. So it is promising to be an ideal ACL scaffold.
ObjectiveTo review the current status and progress of sterilization and preservation for allograft in anterior cruciate ligament reconstruction.MethodsThe related literature about the sterilization and preservation of allografts in anterior cruciate ligament reconstruction was extensively reviewed and summarized.ResultsThere are many sterilization methods for allografts, the most commonly used method is γ-ray irradiation, but the optimal irradiation dose is still unclear. Electron beam irradiation is also available, but excessive dose is harmful to graft shaping. A combined sterilization method combining physics and chemistry methods is still being explored. Cryopreservation is the most commonly used method of preservation. In order to reduce the influence of crystals, the principle of " slow cooling and rapid rewarming” should be adhered to as far as possible.ConclusionThe processing methods of allograft can affect the effectiveness of anterior cruciate ligament reconstruction. The clinical doctors should consider the sterilization and preservation methods in practice.
Objective To compare early graft healing between over-the-top (OTT) and anatomic single-bundle (SB) anterior cruciate ligament (ACL) reconstruction. Methods A clinical data of 40 patients underwent ACL reconstruction, who admitted between June 2021 and October 2022 and met the selective criteria, was retrospectively analyzed. Among them, 20 patients were treated with OTT reconstruction (OTT group) and 20 with SB reconstruction (SB group). There was no significant difference between groups (P>0.05) in the gender, age, affected side, disease duration, degree of meniscus injury, body mass index, and preoperative International Knee Documentation Committee (IKDC) score, Lysholm score, pain visual analogue scale (VAS) score, and KT-2000 measurement. At 3, 6, and 12 months, MRI was performed to measure the signal noise quotient (SNQ) of the proximal end, middle, and distal end of the graft in the two groups, as well as at the corner of the graft with lateral femoral condyle and 1 cm around the femoral fixation point in the OTT group, to observe the degree of graft healing. Before operation and at 3, 6, and 12 months, the knee function and pain were evaluated by IKDC score, Lysholm score, and VAS score. Before operation and at 12 months after operation, the KT-2000 measurement was taken to evaluation the knee joint stability. Results All operations were successfully completed in both groups and the incisions healed by first intention. All patients were followed up 12-15 months (mean, 12.9 months), with no significant difference in the follow-up time between groups (P>0.05). After operation, the IKDC score, VAS score, and Lysholm score improved gradually over time in both groups, with significant differences between different time points (P<0.05). The differences between groups at 3, 6, and 12 months after operation were not significant (P>0.05). The anterior and posterior stability of the knee joint improved significantly in both groups at 12 months after operation, and the difference in KT-2000 measurements was significant when compared with the preoperative value (P<0.05), but the difference of pre- and post-operation between groups was not significant (P>0.05). At 3, 6, and 12 months after operation, MRI showed that the differences in the SNQ of the proximal end and middle of the grafts between the two groups were not significant (P>0.05), and the SNQ of distal end was significantly higher in the SB group than in the OTT group (P<0.05). At each time point, grafts in the OTT group had the highest SNQ at the corner and the lowest at the fixation point, and the differences were significant compared to the other sites (P<0.05). In the two groups, except for the fixation point, the SNQ of the remaining sites were highest at 6 months and lowest at 12 months (P<0.05). In addition, there were significant differences in SNQ between the different sites of grafts (P<0.05), and the SNQ was lowest at proximal end and highest at distal end. At last follow-up, the knee grafts in both groups were in good shape and no graft necrosis or loosening of the internal fixation was observed. Conclusion The knee joint function and graft healing after OTT reconstruction of ACL are similar to those of SB reconstruction, but it should be noted that the healing at the corner of the graft is slower.
ObjectiveTo evaluate the correlation between the Mohawk (MKX) expression level and the collagen fiber diameter of autologous hamstring tendon graft during the stable graft remodeling phase after anterior cruciate ligament (ACL) reconstruction.MethodsBetween January 2018 and August 2018, patients who underwent arth-roscopic single-bundle anatomical ACL reconstruction with autologous hamstring tendons for at least 48 months and also underwent second-look arthroscopy were enrolled in study. During the second-look arthroscopic procedures, ACL graft biopsies were performed from the surface of central part of the ligament. MKX expressions of ACL grafts were analysed by real-time fluorescent quantitative PCR (qRT-PCR). The ultrastructure of collagen fibers of grafts were evaluated by transmission electron microscopy, which included average diameter of collagen fibers (Dc), average diameter of large-diameter collagen fibers (DL), average diameter of small-diameter collagen fibers (DS), and large-small collagen fibers ratio (RL/S). The correlation between MKX expression level and graft collagen fiber diameter was calculated.ResultsTwenty-six patients met the selection criteria and their ACL graft specimens were enrolled in the study. The interval between ACL reconstruction and second-look arthroscopy was 52-128 months, with an average of 78.6 months. Arthroscopic graft remodeling score was 3-6 (mean, 4.8). There were 17 cases of excellent remodeling and 9 cases of fair remodeling. All ACL grafts showed typical bimodal distributions of both large-diameter collagen fibers and small-diameter collagen fibers, but the ultrastructural characteristics of the graft collagen fibers were different according to different remodeling status under arthroscopy. The DC, DL, DS, and RL/S of the graft specimens were (65.2±9.3) nm, (91.6±10.5) nm, (45.7±8.6) nm, and 0.73±0.12, respectively. The relative expression level of MKX was 1.42±0.11, which was positively linearly correlated with DC, DL, and RL/S, and the correlation coefficient was statistically significant (r=0.809, P=0.000; r=0.861, P=0.000; r=0.942, P=0.000), while there was no significant correlation between DS and relative expression level of MKX (r=0.147, P=0.238). Regression analysis showed that the relative expression level of MKX could predict the DC, DL, and RL/S results of the ACL graft specimens (P<0.05).ConclusionAfter autologous hamstring tendon grafts stepped into stabilized remodeling phase, MKX expression level could predict the diameter measurement results of collagen fibers and be used as an important evaluation basis for graft collagen anabolic metabolism.
ObjectiveTo explore the relationship between anterior cruciate ligament (ACL) reconstruction failure and medial meniscus injury and decide whether medial meniscus injury could be the judgment index for ACL reconstruction failure without trauma history.
MethodsBetween March 2011 and December 2015, 117 patients underwent ACL reconstruction, and the clinical data were analyzed retrospectively. All patients had no trauma history after ACL resconstruction. MRI examination showed medial meniscus injury in 56 cases (observation group) and no medial meniscus injury in 61 cases (control group). There was no significant difference in gender, age, side, reconstructive surgery, and follow-up time between 2 groups (P>0.05). The KT-2000 arthrometer was used to measure the difference value of tibial anterior displacement between two knees in 30° knee flexion. Then wether the ACL reconsruction failure was judged according to the evaluation criteria proposed by Rijke et al.
ResultsIn observation group, the difference value of tibial anterior displacement was <3 mm in 7 patients, 3-5 mm in 11 patients, and >5 mm in 38 patients. In control group, the difference value of tibial anterior displacement was <3 mm in 31 patients, 3-5 mm in 18 patients, and >5 mm in 12 patients. The ACL reconstruction failure rate of observation group (67.9%) was significantly higher than that of control group (19.7%) (χ2=27.700, P=0.000).
ConclusionAfter ACL reconstruction, medial meniscus injury occurs under no trauma history circumstances, indicating ACL reconstruction failure.
Objective To investigate the effectiveness of portable bracket of lower limb in the reconstruction of anterior cruciate l igament (ACL) by the long fibular muscle tendon under arthroscopy. Methods Between March 2008 and September 2010, 22 patients with ACL injury were treated. The limb position was maintained by portable bracket of lower limb and ACL was reconstructed with the long fibular muscle tendon under arthroscopy. There were 15 males and 7 females with an average age of 33.8 years (range, 19-64 years). The causes of ACL injury were traffic accident injury in 14 cases, sport trauma in 5 cases, and fall ing injury in 3 cases. The locations were the left knee in 10 cases and the right knee in12 cases, including 12 fresh injuries and 10 old injuries. Of 22 patients, 17 had positive anterior drawer test, 19 had positive pivot shift test, and 20 had positive Lachman test. According to International Knee Documentation Committee (IKDC) criteria, there were 6 abnormal and 16 severely abnormal. The subjective IKDC score was 57.64 ± 6.11. The Lysholm score was 55.45 ± 4.37. Results All incisions healed by first intention, and no complication was found. All patients were followed up 9-38 months (mean, 15 months). At last follow-up, the flexion of the knee ranged from 120 to 135° (mean, 127°). One patient had positive anterior drawer test, 1 patient had positive pivot shift test, and 2 patients had positive Lachman test. No ligament loosening and breakage occurred. According to the IKDC criteria, 10 patients rated as normal, 11 patients as nearly normal, and 1 patient as abnormal. The subjective IKDC score was 90.44 ± 6.11, showing significant difference when compared with preoperative one (t=4.653, P=0.021). The Lysholm score was 90.12 ± 5.78, showing significant difference when compared with preoperative one (t=4.231, P=0.028). Conclusion Portable bracket of lower limb in the reconstruction of ACL has the advantages of saving manpower and easy operation. The long fibular muscle tendon is enough long and b to reconstruct the ACL, which can increase the contact surface between the tendon and bone and is beneficial to tendon-bone heal ing.
ObjectivesTo systematically review the efficacy of exercise therapy on functional and activity recovery after anterior cruciate ligament reconstruction (ACL).MethodsPubMed, EMbase, WanFang Data and CNKI databases were electronically searched to collect randomized controlled trials (RCTs) on the efficacy of exercise therapy on functional and activity recovery after ACL from inception to May 2019. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 11 RCTs involving 602 patients were included. The results of meta-analysis showed that: 1 week (MD=3.07, 95%CI 1.37 to 4.77, P=0.000 4) and 3 weeks (MD=4.53, 95%CI 2.34 to 6.71, P<0.000 1) conventional exercise training rehabilitation effects were better than natural recovery under orthopedic routine care in promoting knee joint function recovery. The recovery effects of over 6 months neuromuscular training was significantly increased compared with conventional rehabilitation (MD=11.48, 95%CI 8.25 to 14.71, P<0.000 01). In addition, there was significant difference between open and closed chain exercise rehabilitation after more than 6 months rehabilitation training (MD=6.77, 95%CI 0.86 to 12.68, P=0.02).ConclusionsThe current evidence shows that over 6 months neuromuscular training significantly enhance the recovery of motor function after anterior cruciate ligament reconstruction. According to different reconstruction methods, individualized rehabilitation program is developed to maximize the recovery of knee joint function. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify above conclusions.
ObjectiveTo compare the incidence of chondral injury using Rigidfix femoral fixation device via the anteromedial approach and the tibial tunnel approach during anterior cruciate ligament (ACL) reconstruction.
MethodsEighteen adult cadaver knees were divided randomly into 2 groups, 9 knees in each group. Femoral tunnel drilling and cross-pin guide insertions were performed using the Rigidfix femoral fixation device through the anteromedial approach (group A) and the tibial tunnel approach (group B). ACL reconstruction simulation was performed at 0, 10, 20, 30, 45, 60, 70, 80, and 90°in the horizontal position. The correlation between incidence of chondral injury and slope angles was analyzed, and then the incidence was compared between the 2 groups.
ResultsThe correlation analysis indicated that the chondral injury incidence increased with the increasing of the slope angle (r=0.611, P=0.000; r=0.852, P=0.000). The incidence of chondral injury was 69.1% (56/81) and 48.1% (39/81) in groups A and B respectively, showing significant difference (χ2=7.356, P=0.007). The sublevel analysis showed that the chondral injury incidence of group A (36.1%, 13/36) was significantly higher than that of group B (0) at 0-30°(χ2=15.864, P=0.000), but no significant difference was found between group A (95.6%, 43/45) and group B (86.7%, 39/45) at 45-90°(P=0.267).
ConclusionIt has more risk of chondral injury to use Rigidfix femoral fixation device via the anteromedial approach than the tibial tunnel approach to reconstruct ACL.
