ObjectiveTo 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.MethodsTwenty 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.ResultsThe 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).ConclusionIn 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.
ObjectiveTo investigate the effects of different concentrations of osteoprotegerin (OPG) combined with deproteinized bone (DPB) on the bone tunnel after the anterior cruciate ligament (ACL) reconstruction.
MethodsThe femoral epiphyseal side was harvested from newborn calf, and allogenic DPB were prepared by hydrogen peroxide-chloroform/methanol method. Then, DPB were immersed in 3 concentrations levels of OPG (30, 60, 100 μg/mL) and 3 concentration ratios (30%, 60%, 100%) of the gel complex were prepared. Sixty healthy New Zealand white rabbits, male or female, weighing (2.7±0.4) kg, were divided randomly into 4 groups (n=15):control group (group A), 30% (group B), 60% (group C), and 100% (group D) OPG/DPB gel complex. The ACL reconstruction models were established by autologous Achilles tendon. Different ratios of OPG/DPB gel complex were implanted in the femoral and tibial bone tunnel of groups B, C, and D, but group A was not treated. The pathology observation (including the percentage of the femoral bone tunnel enlargement) and histological observation were performed and the biomechanical properties were measured at 4, 8, and 12 weeks after operation.
ResultsOne rabbit died of infection in groups A and D, 2 rabbits in groups B and C respectively, and were added. General pathology observation showed that the internal orifices of the femoral and tibia tunnels were covered by a little of scar tissue at 4 weeks in all groups. At 8 weeks, white chondroid tissues were observed around the internal orifices of the femoral and tibia tunnels, especially in groups C and D. At 12 weeks, the internal orifices of the femoral and tibia tunnels enlarged in groups A, B, and C, but it was completely closed in group D. At each time point, the rates of the femoral bone tunnel enlargement in groups B, C, and D were significantly lower than that in group A, and group D was significantly lower than groups B and C (P<0.05); group C was significantly lower than group B at 8 weeks, but no significant difference was found at 4 and 12 weeks (P<0.05). Hisological observation showed that fresh fibrous connective tissue was observed in 4 groups at 4 weeks; there was various arrangements of Sharpey fiber in all groups at 8 weeks and the atypical 4-layer structure of bone was seen in group D; at 12 weeks, Sharpey fiber arranged regularly in all groups, with typical 4-layer structure of bone in groups B, C, and D, and an irregular "tidal line" formed, especially in group D. Biomechanics measurement showed that the maximum tensile load in group D was significantly higher than that in groups A and B at 4 weeks (P<0.05), but no significant difference was shown among groups A, B, and C, and between groups C and D (P>0.05); at 8 weeks, it was significantly higher in groups C and group D than group A, and in group D than group B (P<0.05), but there was no significant difference between groups A, C and group B (P>0.05); at 12 weeks, it was significantly higher in groups C and D than groups A and B, and in group D than group C (P<0.05), but difference was not significant between groups A and B (P>0.05).
ConclusionDifferent concentrations ratios of OPG/DPB gel complexes have different effects on the bone tunnel after ACL reconstruction. 100% OPG/DPB gel complex has significant effects to prevent the enlargement of bone tunnel and to enhance tendon bone healing.
Objective To investigate the changes of knee joint kinematics after anterior cruciate ligament (ACL) reconstruction assisted by personalized femoral positioner based on the apex of deep cartilage (ADC). Methods Between January 2021 and January 2022, a total of 40 patients with initial ACL rupture who met the selection criteria were randomly divided into the study group (using the personalized femoral positioner based on ADC design to assist ACL reconstruction) and the control group (not using the personalized femoral positioner to assist ACL reconstruction), with 20 patients in each group. Another 20 volunteers with normal knee were collected as a healthy group. There was no significant difference in gender, age, body mass index, and affected side between groups (P>0.05). Gait analysis was performed at 3, 6, and 12 months after operation using Opti _ Knee three-dimensional knee joint motion measurement and analysis system, and the 6 degrees of freedom (flexion and extension angle, varus and valgus angle, internal and external rotation angle, anteroposterior displacement, superior and inferior displacement, internal and external displacement) and motion cycle (maximum step length, minimum step length, and step frequency) of the knee joint were recorded. The patients’ data was compared to the data of healthy group. Results In the healthy group, the flexion and extension angle was (57.80±3.45)°, the varus and valgus angle was (10.54±1.05)°, the internal and external rotation angle was (13.02±1.66)°, and the anteroposterior displacement was (1.44±0.39) cm, the superior and inferior displacement was (0.86±0.20) cm, and the internal and external displacement was (1.38±0.39) cm. The maximum step length was (51.24±1.29) cm, the minimum step length was (45.69±2.28) cm, and the step frequency was (12.45±0.47) step/minute. Compared with the healthy group, the flexion and extension angles and internal and external rotation angles of the patients in the study group and the control group decreased at 3 months after operation, and the flexion and extension angles of the patients in the control group decreased at 6 months after operation, and the differences were significant (P<0.05); there was no significant difference in the other time points and other indicators when compared with healthy group (P>0.05). In the study group, the flexion and extension angles and internal and external rotation angles at 6 and 12 months after operation were significantly greater than those at 3 months after operation (P<0.05), while there was no significant difference in the other indicators at other time points (P>0.05). There was a significant difference in flexion and extension angle between the study group and the control group at 6 months after operation (P<0.05), but there was no significant difference of the indicators between the two groups at other time points (P>0.05).Conclusion Compared with conventional surgery, ACL reconstruction assisted by personalized femoral positioner based on ADC design can help patients achieve more satisfactory early postoperative kinematic results, and three-dimensional kinematic analysis can more objectively and dynamically evaluate the postoperative recovery of knee joint.
Objective To compare the effectiveness of I.D.E.A.L technique and transtibial (TT) technique in anterior cruciate ligament (ACL) reconstruction. Methods A clinical data of 60 patients with ACL injury, who were admitted and met the selection criteria between January 2020 and September 2022, was retrospectively analyzed. All patients underwent arthroscopic ACL reconstruction with autologous tendon. During operation, the femoral tunnel was prepared by using I.D.E.A.L technique in 30 cases (I.D.E.A.L group) and using TT technique in 30 cases (TT group). There was no significant difference in baseline data such as age, gender, body mass index, cause of injury, injured side, interval from injury to operation, constituent ratio of combined cartilage and meniscus injury, and preoperative Lysholm score, International Knee Documentation Committee (IKDC) score, visual analogue scale (VAS) score, anterior tibial translation difference, and Blumensaat angle between the two groups (P>0.05). The length of hospital stay and the occurrence of early and late complications were recorded. During follow-up, the Lysholm score, IKDC score, and VAS score were used to evaluate knee joint function and pain degree, and the anterior tibial translation difference was measured. MRI reexamination was performed to observe the healing of the graft, and the signal to noise quotient (SNQ) values of the femoral end, middle section, and tibial end of the graft, as well as the Blumensaat angle of the knee joint were measured. The differences in tibial anterior translation difference and Blumensaat angle before and after operation (change values) were calculated and compared between the two groups. Results The incisions in both groups healed by first intention after operation, and there was no significant difference in the length of hospital stay between the two groups (P>0.05). All patients were followed up 12-18 months, with an average of 14.9 months. The Lysholm score and IKDC score of the knee joint in both groups after operation increased when compared with those before operation, and the VAS score decreased. Compared to preoperative scores, except for the VAS score of the TT group at 1 week after operation (P>0.05), there were significant differences in all scores at different time points postoperatively in the two groups (P<0.05). The above scores in both groups showed a further improvement trend with the prolongation of time after operation. There were significant differences in Lysholm score and VAS score among 1 week, 1 month, 3 months, 6 months, and 12 months after operation in the two groups (P<0.05). The IKDC score of both groups at 1 month after operation was significantly different from that at 1 week after operation (P<0.05). At 1 week after operation, the Lysholm score and IKDC score in the I.D.E.A.L group were significantly higher than those in the TT group (P<0.05), and the VAS score was significantly lower (P<0.05); there was no significant difference between the two groups at 1, 3, 6, and 12 months after operation (P>0.05). At 12 months after operation, the anterior tibial translation differences in both groups were significantly lower than those before operation (P<0.05); and the change value in the I.D.E.A.L group was significantly higher than that in the TT group (P<0.05). The incidences of early and late complications in the I.D.E.A.L group were significantly lower than those in the TT group (P<0.05). At 12 months after operation, MRI examination showed that the grafts of the knee joint in both groups survived well, and the Blumensaat angles of both groups were significantly smaller than those before operation (P<0.05). The change value of the Blumensaat angle in the I.D.E.A.L group was significantly higher than that in the TT group (P<0.05). The SNQ values of the femoral end, middle section, and tibial end of the graft in the I.D.E.A.L group were significantly higher than those in the TT group (P<0.05). Conclusion The early effectiveness of ACL reconstruction by using the I.D.E.A.L technique is better, the knee joint is more stable, and the incidence of postoperative complication is lower. However, the maturity of the graft after reconstruction using the TT technique is higher.
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.
Objective To investigate whether the outlet of the femoral tunnel will cause iatrogenic injury to the medial collateral ligament (MCL) during posterior cruciate ligament reconstruction (PCLR) and estimate the safe angle of femoral tunnel placement. MethodsThirteen formaldehyde-soaked human knee joint specimens were used, 8 from men and 5 from women; the donors’ age ranged from 49 to 71 years, with an average of 61 years. First, the medial part of the femur was carefully dissected to clearly expose the region of the MCL course and attachment on the femoral medial aspect and to outline the anterior margin of the region with a marked line. The marked line divided the medial femoral condyle into an area with an MCL course and a bare bone area which is regarded relatively safe for no MCL course. Then, the posterior cruciate ligament (PCL) was cut to identify the femoral attachment of the PCL. After the knee joint was fixed at a 120° flexion angle, the process of femoral tunnel preparation for the PCL single-bundle reconstruction was simulated. The inside-out technique was used to drill the femoral tunnel from the PCL femoral footprint inside the knee joint with an orientation to exit the medial condyle of the femur, and the combination angle of the two planes, the axial plane and the coronal plane, was adapted to the process of drilling femoral tunnels at different orientations. The following 15 angle combinations were used in the study: 0°/30°, 0°/45°, 0°/60°, 15°/30°, 15°/45°, 15°/60°, 30°/30°, 30°/45°, 30°/60°, 45°/30°, 45°/45°, 45°/60°, 60°/30°, 60°/45°, 60°/60° (axial/coronal). The positional relationship between the femoral tunnel outlet on the femoral medial condyle and the marked line was used to verify whether the tunnel drilling angle was a risk factor for MCL injury or not, and whether the shortest distance between the femoral exit center and the marked line was affected by the various angle combinations. Furthermore, the safe orientation of the femoral tunnel placement would estimated. ResultsWhen creating the femoral tunnel for PCLR, there was a risk of damage to the MCL caused by the tunnel outlet, and the incidence was from 0 to 100%; when the drilling angle of the axial plane was 0° and 15°, the incidence of MCL damage was from 69.23% to 100%. There was a significant difference in the incidence of MCL damage among femoral tunnels of 15 angle combinations (χ2=148.195, P<0.001). By comparison between groups, it was found that when drilling femoral tunnels at 5 combinations of 45°/45°, 45°/60°, 60°/30°, 60°/45°, and 60°/60° (axial/coronal), the shortest distances between the tunnel exit and the marked line were significantly different than 0°/45°, 0°/60°, 15°/45°, 15°/60°, and 30°/30° (axial/coronal) (P<0.05). Additionally, after comparing the median of the shortest distance with other groups, the outlets generated by these 5 angles were farther from the marked line and the posterior MCL. ConclusionThe creation of the femoral tunnel in PCLR can cause iatrogenic MCL injury, and the risk is affected by the tunnel angle. To reduce the risk of iatrogenic injury, angle combinations of 45°/45°, 45°/60°, 60°/30°, 60°/45°, and 60°/60° (axial/coronal) are recommended for preparing the femoral tunnel in PCLR.
ObjectiveTo investigate the effect of the femoral tunnel angle on the femoral tunnel after anterior cruciate ligament (ACL) reconstruction in rabbits.
MethodsFifty-four healthy 4-5 months old rabbits (weighing, 1.8-2.3 kg, male or female) were randomly divided into 3 groups (n=18). The ACL reconstruction models of the right knee were established in 3 experimental groups using its Achilles tendons, and the left knee served as the control group. On the coronal position, the angle between the femoral tunnel and the femoral shaft axis was 30°, 45°, and 60°. The level of tumor necrosis factor α (TNF-α) in the synovial fluid at 1, 2, and 4 weeks, the maximum load of the ligament and the rate of bone tunnel enlargement at 4, 8, and 12 weeks were detected.
ResultsThe level of TNF-α significantly increased, and the maximum load of the ligament significantly decreased in the 3 experimental groups when compared with ones in the control group (P<0.05), but no significant difference was found among 3 experimental groups (P>0.05). The bone tunnel enlargement was observed in 3 experimental groups at each time point and reached the peak at 4 weeks, but no significant difference was shown among 3 groups (P>0.05).
ConclusionThe 30-60° angle between the femoral tunnel and the femoral shaft axis in the coronal position has no significant effect on the femoral tunnel enlargement after ACL reconstruction in rabbits.
Objective To investigate the effectiveness of modified single patellar tunnel medial patella femoral ligament (MPFL) reconstruction in the treatment of recurrent patellar dislocation. MethodsBetween January 2023 and June 2023, a total of 61 patients with recurrent patellar dislocation who underwent MPFL reconstruction with autologous semitendinosus were enrolled and divided into 2 groups using random number table method. In the patellar anchor group, 31 patients were treated with MPFL reconstruction with double medial patellar anchors, and 30 patients in the patellar tunnel group were treated with MPFL reconstruction with single patellar tunnel. The femoral ends of both groups were fixed with absorbable compression screws. There was no significant difference in baseline data such as gender, age, side, tibial tubercle-trochlear groove (TT-TG), Q angle, Caton-Deschamps index, number of dislocation, and preoperative Kujala score, preoperative patellar inclination angle (P>0.05). Patellar tunnel, patellar anchor position, patellar reduction, and the patellar inclination angle were measured by CT scan after operation. Kujala score was used to evaluate the function of knee joint before operation, at 2 weeks and 1, 3, 6, 12 months after operation. Incision aesthetic satisfaction score was performed at 3 months after operation. The signal-to-noise quotient (SNQ) of the transplanted tendon was measured by knee MRI at 12 months after operation to compare the maturity of the graft between the two groups. Results There was no significant difference in operation time and intraoperative blood loss between the two groups (P>0.05). Knee CT reexamination showed that the patellar tunnel and the patellar anchor position were consistent with the intraoperative fluoroscopy. There was no significant difference in the difference of the patellar inclination angle between the two groups before and after operation (P>0.05). All patients were followed up 12-14 months (mean, 12.8 months). There was 1 case of patellar anchor suture rejection in patellar anchor group, and the wound healed after debridement and dressing change. During the follow-up, there was no complication such as recurrence of patellar dislocation, infection and postoperative stiffness. The Kujala scores of the two groups significantly improved at each time point after 1 month of operation when compared with those before operation (P<0.05), and the Kujala scores of the two groups returned to normal levels at 3 months after operation. The Kujala score in the patellar tunnel group was significantly higher than that in the patellar anchor group in the very early stage (2 weeks) (P<0.05), and there was no significant difference between the two groups at other time points (P>0.05). Patients in the patellar tunnel group were significantly better than those in the patellar anchor group in the score of incision aesthetic satisfaction at 3 months after operation and the SNQ at 12 months after operation (P<0.05). Conclusion Modified single patellar tunnel MPFL reconstruction was used to treat patients with recurrent patellar dislocation without pathological TT-TG. The slide-fixation structure formed by single patellar tunnel positioning provides a variable degree of freedom for the reconstructed MPFL, which shows good effectiveness in the very early stage of the rehabilitation process.
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.
To observe the histology change of the insertion using different diamertrical bone tunnel in anterior cruciate l igament (ACL) reconstruction. Methods Ninety Japanese rabbits were selected, wihout female and male l imit, weighing 2.5-3.0 kg, and were randomly divided into 3 groups, 30 in each group. The ratio of transplantation l igament diameter and bone tunnel diameter was 1/1 (group A), the ratio was 1/1.5 (group B), and the ratio was 1/2 (group C). Bone tunnel observation and histology observation were carried out in the 4th, 8th and 16th weeks postoperat ively. Results Wound healed well in 3 groups. The mean time of walking functional recovery was 1.5, 2.0 and 3.5 days in groups A, B and C respectively. After 4 weeks of operation, more soft tissues at tunnel entry were observed in group A and group B than in group C; after 8 weeks of operation, there was no crevice at bone-tunnel entry of the groups A and B, there was no improvement in group C; after 16 weeks of operation, groups A and B showed the normal insertion, group C had no normal insertion. Histology observation: in groups A, B and C, bone-tunnel was filled with loose connective tissue after 4 weeks of operation; group A and group B emerged the discontinuation ACL insertion tidal l ine after 8 weeks of operation, group C had no insertion; groups A and B emerged the similarity normal ACL insertion tidal l ine structure after 16 weeks of operation, but group C had no this structure. The results of ultimate tensile strength in groups A, B and C were (75.44 ± 7.06), (91.37 ± 6.14) and (126.91 ± 4.61) N respectively at 4 weeks; the results were (74.31 ± 4.81), (88.30 ± 7.46) and (124.34±8.44) N respectively at 8 weeks; and the results were (62.20 ± 5.32), (71.53 ± 5.99) and (83.62 ± 5.69) N respectively at 16 weeks. There was no significant difference between group A and group B (P gt; 0.05), and there were significant differences between groups A, B and group C (P lt; 0.05). Conclusion In the ACL reconstruction, the ratioof transplantation l igament diameter and bone tunnel diameter being 1/1.5 will not affect the insertion outcome, but if theratio less than the l imit it will affect the insertion outcome.
