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 investigate the best knee flexion angle by analyzing the length and orientation of the femoral tunnel through anteromedial portal (AM) at different flexion angles during anterior cruciate ligament (ACL) reconstruction. MethodsTwelve fresh cadaveric knees were selected to locate the center of ACL femoral footprint through AM using the improved hook slot vernier caliper, and to locate the posterior bone cortex using a diameter 3 mm ball at flexion of 90, 100, 110, 120, and 130°. The femoral tunnel length, standard coronal and sagittal plane angles, and the position relation between exit point and the lateral epicondyle were measured; the tunnel orientation on the anteroposterior and lateral X-ray films was also measured. ResultsWith increasing flexion of the knee, the femoral tunnel length showed a first increasing and then stable tendency; significant difference was found between at flexion of 90°and at flexions of 100, 110, 120, and 130°, and between flexions of 100°and 120°(P<0.05). The femoral tunnel showed a trend of decreasing with coronal angle, whereas gradually increasing with sagittal angle. The knee flexion angle had significant difference either among flexions of 90, 110, and 130°or between flexions of 100°and 120°(P<0.05). The exit point of the femoral tunnel located at the lateral epicondyle of the femur proximal to posterior region at flexion of 90°in all knees, and at flexion of 100°in 7 knees, but it located at the lateral epicondyle of the femur proximal to anterior region at flexion of 110, 120, and 130°in all knees. As the knee flexion angle increasing, the angle between femoral tunnel with the tangent of internal-external femoral condyle on anteroposterior X-ray films showed a trend of decreasing gradually, but a trend of increasing gradually on lateral X-ray films. On the anteroposterior X-ray films, significant differences were found in the angle either among flexions of 90, 110, and 130°or between flexions of 100°and 120°(P<0.05). On the lateral X-ray films, there were significant differences in the angle among flexions of 90, 100, 110, 120, and 130°(P<0.05). ConclusionDuring ACL reconstruction by AM, 110°is the best flexion angle, which can get the ideal femoral tunnel.
ObjectiveTo systematically review the progress of different methods for femoral tunnel positioning in anterior cruciate ligament (ACL) reconstruction and provide a clinical reference for treatment of ACL rupture.MethodsThe literature about the femoral tunnel positioning in ACL reconstruction was widely reviewed. The advantages and disadvantages and the clinical results of each method were summarized.ResultsCurrently in ACL reconstruction, methods for femoral tunnel positioning include transtibial technique (TT), anteromedial technique (AM), outside-in (OI), modified TT (mTT), and computer assisted surgery. There is no significant difference in the postoperative effectiveness between TT technique and AM technique. Compared with the TT technique, the OI technique has higher rotational stability of knee, but there is no significant difference in clinical results. The femoral tunnel located by mTT technique is closer to the anatomical placement than that of TT technique, but mTT technique is not effective for systematically anatomic femoral tunnel positioning, and further research is needed to prove its advantages.ConclusionDifferent femoral tunnel positioning methods have their own advantages and disadvantages, and there is no definite evidence that one is superior than the rest.
Objective To explore the effectiveness of the modified Lemaire procedure in anterior cruciate ligament reconstruction (ACLR) in patients with a highly positive pivot shift test. Methods The clinical data of 18 patients with anterior cruciate ligament (ACL) rupture and highly positive pivot shift test between April 2020 and September 2022 were retrospectively analyzed. There were 13 males and 5 females with an average age of 28.3 years (range, 17-41 years). Causes of injury included 11 cases of direct violence injury, including 6 cases of traffic accident injury, 4 cases of sports injury, 1 case of falling injury; 7 cases of indirect violence injury, all sports injury. All patients had complete ACL rupture, including 15 acute injuries and 3 old injuries. The preoperative pivot shift test was grade Ⅱ in 9 cases and grade Ⅲ in 9 cases. All patients were treated with ACLR combined with modified Lemaire procedure. The International Knee Documentation Committee (IKDC) score and Lysholm score were used to evaluate the effectiveness before operation and at 3, 6, 12 months after operation. KT-2000 arthrometer was used to measure the anterior stability of the knee joint, and the difference between the healthy and affected sides was recorded. Pivot shift test was used to evaluate the rotational stability of the knee joint. During the follow-up, X-ray films were taken to observe the bone tunnel and internal fixation, and MRI was used to examine the healing of ACL, anterolateral collateral ligament and fibular collateral ligament grafts.Results All patients completed the operation successfully without complications such as knee joint infection, vascular and nerve injury. All patients were followed up 12-19 months (mean, 13.2 months). After operation, the rotational stability of the knee joint recovered satisfactorily, and there was no adverse symptom such as knee instability and locking at last follow-up. X-ray film and MRI showed that the bone tunnel was anatomically located and healed well, the internal fixation was in good position, and the reconstructed ACL and iliotibial band were continuous and in good tension. The IKDC score, Lysholm score, and the difference of KT-2000 between the healthy and the affected sides significantly improved at 3, 6, and 12 months after operation (P<0.05). All the indicators further improved with time after operation, except that there was no significant difference in IKDC score between 3 and 6 months after operation and in the difference of KT-2000 between 3 months and 6, 12 months after operation (P>0.05), and there were significant differences in other indicators between different time points (P<0.05). Pivot shift test was negative immediately after operation and at last follow-up. Conclusion In ACL injuries with a highly positive pivot shift test, ACLR combined with the modified Lemaire procedure can effectively restore anterolateral knee stability, leading to satisfactory knee stability and function in the early postoperative period.
Objective To evaluate the tendon regeneration after anterior cruciate ligament (ACL) reconstruction with semitendinosus tendon and gracilis tendon autografts by MRI. Methods Between September 2007 and September 2009, 52 patients undergoing ACL reconstructions with semitendinosus tendon and gracilis tendon autografts were enrolled. There were 29 males and 23 females with an average age of 31.6 years (range, 19-42 years). The left knees were involved in 34 cases and the right knees in 18 cases. The injury was caused by traffic accident in 11 cases, by sports in 38 cases, by heavy pound injury in 2 cases, and by other in 1 case. The time between injury and operation was 6 days to 31 months (median, 11.4 months). Joint pain occurred in 19 cases, joint instability in 28 cases, and joint swelling in 5 cases. The physical examination on admission showed thigh amyotrophy in 7 cases (thigh circumference side-to-side difference gt; 1 cm) and limitation of joint motion in 2 cases. The results of floating patella test, Lachman test, pivot shift test, and anterior drawer test were positive in 5, 51, 49, and 52 cases, respectively. The range of motion of knee was (127.77 ± 5.73)°, International Knee Documentation Committee (IKDC) score was 49.50 ± 4.08, and Lysholm score was 52.40 ± 3.45. Of the patients, 23 were accompanied with medial meniscus tear, 6 with lateral meniscus tear, 2 with plica synovialis, and 1 with loose body. Results All incisions healed by first intention. All the patients were followed up 12-18 months (mean, 14.9 months). At 12 months postoperatively, the results of Lachman test and pivot shift test were positive in 1 case, respectively; the results of anterior drawer test were negative in 52 cases. The range of motion of knee was (131.91 ± 1.81)°, Lysholm score was 94.98 ± 2.77, IKDC score was 93.65 ± 2.42; and there were significant differences when compared with the preoperative ones (P lt; 0.05). At 12 months postoperatively, at 90° resisted flexion of the knee, a very distinct fibrous band could be identified on the posteromedial aspect of the knee in 39 cases. MRI showed that both semitendinosus tendon and gracilis tendon regeneration in 10 cases, only semitendinosus tendon regeneration in 29 cases, only gracilis tendon regeneration in 2 cases, and no tendon regeneration in 11 cases. The regeneration rate of the semitendinosus tendon was 75.0% (39/52); the regeneration rate of the gracilis tendon was 23.1% (12/52); and the regeneration rate of the semitendinosus tendon and gracilis tendon was 78.8% (41/52). Conclusion MRI results suggest that some of the semitendinosus tendon and gracilis tendon could regenerate after harvested for ACL reconstruction.
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 clarify the intervention guidance of return to sports WeChat applet and evaluate the rehabilitation effectiveness after anterior cruciate ligament (ACL) reconstruction. MethodsBetween September 2020 and September 2022, 80 patients who met the selection criteria and underwent ACL anatomical single bundle reconstruction were selected as the research objects. According to the double-blind random method, they were divided into the applet group and the regular group, with 40 cases in each group. Patients in the applet group were rehabilitated under the guidance of the return to sports WeChat applet, and the patients were asked to perform the test once a month after operation, including patients’ subjective scores [Tegner score, knee injury and osteoarthritis outcome score (KOOS), International Knee Documentation Committee (IKDC) score, American Hospital for Special Surgery (HSS) score], psychological assessment [ACL recovery sports injury scale (ACL-RSI) score], jumping test, balance test, bending angle test. Patients in the regular group were followed up by doctors and nurses regularly by telephone every month. All the patients were reexamined at 3, 6, 9, and 12 months after operation, and the range of motion of the knee joint with 6 degrees of freedom (flexion and extension angle, varus and valgus angle, internal and external rotation angle, anteroposterior displacement, superior and inferior displacement, and internal and external displacement) recorded by Opti_Knee three-dimensional knee joint motion measurement gait analysis system was observed. The anterior tibial translation difference (ATTD) was measured by Ligs knee measuring instrument when a forward thrust of 120 N was applied to the posterior part of the proximal tibia. Tegner score, IKDC score, KOOS score (including KOOS-Pain score, KOOS-Symptoms score, KOOS-Activities of daily living score, KOOS-Sport score, and KOOS-Quality of life score), HSS score, ACL-RSI score, jumping ability, balance ability, patients’ satisfaction with the rehabilitation process, and ACL healing grading according to ACL continuity and signal intensity shown by MRI. Results There were significant differences in various indicators between different time points after operation in the two groups (P<0.05). At 3 months after operation, except that the ACL-RSI score of the applet group was significantly higher than that of the regular group (P<0.05), there was no significant difference in the other indicators between the two groups (P>0.05). At 6 months after operation, the ACL-RSI score, IKDC score, Tegner score, KOOS scores of different items, HSS score, balance and jumping ability of the applet group were significantly higher than those of the regular group (P<0.05), and there was no significant difference in the other indicators between the two groups (P>0.05). At 9 months after operation, there was no significant difference in all indicators between the two groups (P>0.05). At 12 months after operation, 27 cases (67.5%) in the applet group and 21 cases (52.5%) in the regular group returned to sport, with a significant difference of the return to sports incidence between the two groups [RR(95%CI)=1.50 (1.00, 2.25), P=0.049]. In the applet group, 27 cases were very satisfied with the rehabilitation process, 10 cases were satisfied, 2 cases were basically satisfied, and 1 case was not satisfied, while 19, 13, 5, and 3 cases in the regular group, respectively. The satisfaction degree of the applet group was significantly better than that of the regular group (P=0.049). MRI examination of the two groups showed that the ACL was continuous without secondary rupture or necrosis. The ACL healing grade of the applet group was 31 cases of grade 1 and 9 cases of grade 2, and that of the regular group was 28 cases of grade 1 and 12 cases of grade 2, there was no significant difference in ACL healing grade between the two groups (P=0.449). ConclusionThe application of return to sports WeChat applet in the rehabilitation of patients after ACL reconstruction can significantly reduce the fear of return to sports and improve the rate of return to sports. The return to sports WeChat applet is convenient to operate, with high utilization rate and high patient compliance, which significantly improves the satisfaction.
Objective To study the feasibility of virtual intercondylar notchplasty by applying MRI two-dimensional (2D) images to reconstruct three-dimensional (3D) images and measure the size of intercondylar notch. Methods Thirty healthy volunteers who had no knee joint disease and surgery history were selected. There were 15 females and 15 males with an age range of 20-30 years, weight range of 45-74 kg, and height range of 150-185 cm. They were divided into male group and female group, and the knees of each group were divided into 2 subgroups (the left group and right group). MRI scan of the left and right knees was performed, and the 2D images of MRI were imported into Mimics10.01 medical image control system for 3D reconstruction. The related anatomical data as follows were measured from the 3D digital model and analyzed by statistical software: notch width (NW), condylar width (CW), and notch width index (NWI). Then the 3D knee images of patients with anterior cruciate ligament (ACL) injury were collected between January and March 2010, and 4 patients with narrow intercondylar notch (NWI≤0.2) were selected for reconstructing the 3D model of the knee and simulating the intercondylar notch plasty. Then, the volume of osteotomy in 3D model was calculated and applied in the ACL reconstruction surgery, and whether the graft had impingement with intercondylar notch or not was evaluated. Results There were significant differences in NW and CW between male group and female group (P≤lt;≤0.05), but no significant difference was found in the NWI (P≤gt;≤0.05). And there was no significant difference in NW, CW, and NWI between the left and right knees both in male group and female group (P≤gt;≤0.05). After ACL reconstruction and intercondylar notchplasty, the shape of intercondylar notch became normal (NWI≤gt;≤0.22), no impingement occurred between the graft and intercondylar notch under arthroscopy within 3-month follow-up. Conclusion The shape of intercondylar notch of 3D model based on MRI 2D images is similar to the real intercondylar notch. NWI is one of important indexes which can reflect the narrow level of intercondylar notch. The virtual intercondylar notchplasty may provide preoperative plan and guidence for ACL reconstruction operation to avoid the impingement between graft and intercondylar notch after surgery.
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.