Do the Clinical and Radiological Features of Knees with Mucoid Degeneration of the Anterior Cruciate Ligament Differ According to Knee Osteoarthritis Status?

Background: The etiology and pathology of mucoid degeneration of the anterior cruciate ligament (MD-ACL) remain poorly understood. MD-ACL may be associated with knee osteoarthritis (OA) or a mechanism other than OA. This study evaluated the radiological differences between knees with MD-ACL and those with a normal ACL and compared the clinical and radiological features of knees with MD-ACL according to the knee OA status. Methods: This retrospective study compared the radiological features of the intercondylar notch width index (NWI) and posterior tibial slope (PTS) of 67 MD-ACL patients (MD group) and 67 age-, sex-, and OA grade-matched patients with a normal ACL (control group). During the subgroup analysis, MD-ACL patients were divided into the non-OA subgroup (n = 41) and OA subgroup (n = 26). The pain location and characteristics of the knee, PTS, and NWI were compared between these subgroups. Results: Compared to the control group, the MD group had a lower NWI (0.26 ± 0.03 vs. 0.28 ± 0.01, p < 0.001) and a larger PTS (11.3° ± 3.0° vs. 9.2° ± 2.5°, p < 0.001). During the subgroup analysis, the most common pain locations were the posterior and medial aspects of the knee in the non-OA subgroup (43.9%) and OA subgroup (53.8%), respectively. Pain on terminal flexion was the most common pain characteristic in both subgroups (non-OA subgroup, 73.1%; OA subgroup, 53.8%). The PTS was not different between subgroups (11.7° ± 3.2° in the non-OA subgroup vs. 10.6° ± 2.7° in the OA subgroup; p = 0.159). However, the non-OA subgroup had a lower NWI than the OA subgroup (0.25 ± 0.03 vs. 0.28 ± 0.02, p = 0.001). Conclusions: Patients with MD-ACL had a lower NWI and a larger PTS than patients with a normal ACL. Furthermore, the clinical and radiological features of MD-ACL differed according to the knee OA status. A narrow intercondylar notch may be more closely associated with the development of MD-ACL without OA.

Anterior cruciate ligament femoral side retained stump technique reduces enlargement of the femoral bone tunnel after anterior cruciate ligament reconstruction.

BACKGROUND: Enlargement of the bone tunnel has become an unavoidable early complication after anterior cruciate ligament (ACL) reconstruction, whether it is a single or double-bundle ACL reconstruction. Preservation of the ACL stump in ACL reconstruction reduces enlargement of the bone tunnel. The purpose of this study was to investigate the question of whether single-bundle ACL reconstruction using the ACL femoral side retained stump technique reduces enlargement of the femoral tunnel. METHODS: Forty patients who underwent single-bundle reconstruction of the ACL were included in this study. The patients were categorized into a Remnant preservation group (Group R) and the Non-remnant preservation group (Group N). In the Remnant preservation group, a high-flexion femoral side retained stump technique was used intraoperatively for the establishment of the femoral side bone tunnel, and in the Non-remnant preservation group, the conventional femoral positioning method was used (we used a femoral positioning drill for localization and drilling of the femoral bone tunnel), and MRI of the operated knee joints was performed at 6 months postoperatively. We measured the internal diameter of the femoral bone tunnel at 5 mm from the intra-articular outlet of the femoral bone tunnel on an MRI scan image perpendicular to the femoral bone tunnel. The size of the tunnel was compared between the intraoperative drilling of the bone tunnel and the size of the bone tunnel at 6 months postoperatively. Postoperative clinical assessment was Lysholm score. RESULTS: After a 6-month follow-up of 40 patients, the diameter of the femoral tunnel at a distance of 5 mm from the inner opening of the femoral tunnel was 10.96 ± 0.67 mm and 10.11 ± 0.62 mm in patients of group N and group R, respectively, and the difference was statistically significant (P < 0.05).The diameter of the femoral tunnel at 6 months postoperatively in group N and group R compared to the intraoperative bone tunnel increased by 2.58 ± 0.24 mm and 1.94 ± 0.31 mm, and the difference was statistically significant (P < 0.05).The femoral tunnel enlargement rates of group N and group R were 30.94 ± 3.00% and 24.02 ± 5.10%, respectively, and the differences were significant (P < 0.05). CONCLUSION: ACL femoral side retained stump technique does not sacrifice the ideal location of the femoral tunnel and is able to preserve the possible benefits of the ACL stump: reduced femoral tunnel enlargement.

Addition of anterolateral ligament reconstruction to primary anterior cruciate ligament reconstruction could benefit recovery of functional outcomes.

This study aimed to compare functional outcomes sequentially up to 1 year after combined anterior cruciate ligament reconstruction (ACLR) and anterolateral ligament reconstruction (ALLR) and isolated ACLR. Fifty patients who underwent ACLR with versus without ALLR were analyzed at four different time points (preoperatively and 3, 6, and 12 months postoperatively). For the functional outcomes, muscle strength and acceleration time (AT) were measured using an isokinetic dynamometer. Proprioception was evaluated using joint position sense and dynamic postural stability. Patient-reported outcomes were measured using the Tampa Scale for Kinesiophobia (TSK-11) scores. Functional performance was assessed using single-leg hop distance (SLHD) and Limb Symmetry Index. In the operated knees, quadriceps (at 6 months postoperatively, p = 0.003) and hamstring (at 6 and 12 months postoperatively, p < 0.001) strength were significantly higher in the combined ACLR and ALLR group than the isolated ACLR group. The TSK-11 (at 6 and 12 months postoperatively, p < 0.001) was significantly lower in the combined ACLR and ALLR group than the isolated ACLR group. SLHD was significantly higher in the combined ACLR and ALLR group than the isolated ACLR group (at 6 months, p = 0.022 and at 12 months, p = 0.024). The addition of ALLR to primary ACLR yielded better muscle performance, fear of movement, and functional performance than isolated ACLR.

Effects of various load magnitudes on ACL: an in vitro study using adolescent porcine stifle joints.

INTRODUCTION: The escalating incidence of anterior cruciate ligament (ACL) injuries, particularly among adolescents, is a pressing concern. The study of ACL biomechanics in this demographic presents challenges due to the scarcity of cadaveric specimens. This research endeavors to validate the adolescent porcine stifle joint as a fitting model for ACL studies. METHODS: We conducted experiments on 30 fresh porcine stifle knee joints. (Breed: Yorkshire, Weight: avg 90 lbs, Age Range: 2-4 months). They were stored at - 22 °C and a subsequent 24-h thaw at room temperature before being prepared for the experiment. These joints were randomly assigned to three groups. The first group served as a control and underwent only the load-to-failure test. The remaining two groups were subjected to 100 cycles, with forces of 300N and 520N, respectively. The load values of 300N and 520N correspond to three and five times the body weight (BW) of our juvenile porcine, respectively. RESULT: The 520N force demonstrated a higher strain than the 300N, indicating a direct correlation between ACL strain and augmented loads. A significant difference in load-to-failure (p = 0.014) was observed between non-cyclically loaded ACLs and those subjected to 100 cycles at 520N. Three of the ten samples in the 520N group failed before completing 100 cycles. The ruptured ACLs from these tests closely resembled adolescent ACL injuries in detachment patterns. ACL stiffness was also measured post-cyclical loading by applying force and pulling the ACL at a rate of 1 mm per sec. Moreover, ACL stiffness measurements decreased from 152.46 N/mm in the control group to 129.42 N/mm after 100 cycles at 300N and a more significant drop to 86.90 N/mm after 100 cycles at 520N. A one-way analysis of variance (ANOVA) and t-test were chosen for statistical analysis. CONCLUSIONS: The porcine stifle joint is an appropriate model for understanding ACL biomechanics in the skeletally immature demographic. The results emphasize the ligament's susceptibility to injury under high-impact loads pertinent to sports activities. The study advocates for further research into different loading scenarios and the protective role of muscle co-activation in ACL injury prevention.

[Clinical outcome of combined over-the-top reconstruction with modified Lemaire procedure in one-stage revision anterior cruciate ligament reconstruction].

Objective: To investigate the clinical effect of over-the-top (OTT) reconstruction of the anterior cruciate ligament (ACL) combined with the modified Lemaire technique in one-stage ACL revision. Methods: It's a retrospective study. The clinical data of 37 patients who underwent one-stage revision of ACL using OTT combined with modified Lemaire technique from April 2020 to May 2023 in the Department of Sports Medicine of Xinhua Hospital Affiliated to Dalian University were retrospectively analyzed. There were 28 males and 9 females with a mean age of (32.7±5.7) years. The postoperative knee function and surgical revision effect were evaluated by subjective and objective evaluation indexes of the knee joint before and 3 months and 24 months after surgery. The subjective evaluation indexes included the International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner score; and the objective evaluation indexes included the anterior-posterior static displacement distance of the tibia, tibia-femur relative rotation angle, the Lachman test, the axial shift test, and the ratio of the loss of muscle strength of the lower limb. Results: At the final follow-up, all patients returned to pre-injury motor level, with significant improvements in IKDC scores (45.3±6.8 preoperatively, 67.5±4.7 and 93.2±2.3 at 3 months and 2 years after the operation, respectively), Lysholm scores (57.2±2.6 preoperatively, 72.6±2.9 and 89.7±3.7 at 3 months and 2 years after the operation, respectively), and Tegner scores (3.1±0.7 preoperatively, 4.9±0.6 and 5.8±1.3 at 3 months and 2 years after the operation, respectively) (all P<0.001). The anterior-posterior static displacement distance of the tibia reduced significantly [from (5.2±0.5) mm before the operation to (1.4±0.5) mm at 2 years postoperatively) (P<0.001)]; and the relative rotation angle of the tibia-femur restored to the normal physiological range, it was reduced from 6.2°±1.2° before the operation to 1.7°±0.3° 2 years after (P<0.001). The Lachman test and axial shift test at 2 years postoperatively were all negative. The muscle strength loss ratio of the affected lower limb was significantly better than that before the operation (P<0.001). Conclusion: The use of OTT reconstruction combined with modified Lemaire technique for revision of ACL in patients with ACL reconstruction failure can circumvent the tunnel problem for one-stage revision and better restore the stability and function of the knee joint, with ideal clinical results.

Comprehensive Clinical Examination of ACL Injuries.

A comprehensive clinical examination of the potentially anterior cruciate ligament (ACL)-deficient knee should proceed as follows: inspection; palpation; range of motion; varus and valgus stress; neurovascular status; and finally provocative maneuvers. The Lachman, anterior drawer, Lever, and pivot shift tests are all greater than 90% specific for ACL pathology. Due to the relatively high coincidence of ACL injuries and those to the posterior cruciate ligament, posterolateral corner , posteromedial corner , and menisci, it is critical that the examiner perform provocative maneuvers to evaluate the integrity of these structures as well.

The impact of early weight-bearing on results following anterior cruciate ligament reconstruction.

INTRODUCTION: Anterior cruciate ligament (ACL) ruptures are common injuries that typically affect young, physically active individuals and may require surgical reconstruction. Studies have shown that the long time success of ACL reconstruction depends on the surgical technique and the postoperative rehabilitation strategy. However, there is still no consensus on the content of rehabilitation programs. Hence, additional research is required to elucidate the significance of early weight-bearing in the rehabilitation process following ACL reconstruction. The aim of this article is to examine the impact of weight-bearing on the clinical results of ACL reconstruction. MATERIALS AND METHODS: We retrospectively reviewed patient records who had undergone arthroscopic reconstruction using a semitendinosus-gracilis tendon graft for anterior cruciate ligament rupture between January 2018 and December 2020. The study included the data of 110 patients. The patients were split into two groups: Group 1 underwent early weight-bearing, while Group 2 followed a non-weight-bearing regimen for three weeks. We assessed the patients using the anterior drawer test, Lachman test, range of motion, Lysholm knee scale, Cincinnati scale, Tegner scale, International Knee Documentation Committee (IKDC) form and clinical records. Analytical tests were conducted to compare the results. RESULTS: The complication rates did not show a significant difference between the groups. Group 1 had higher frequencies of positive anterior drawer and Lachman tests. The Lysholm and Cincinnati knee scores of patients in Group 1 were notably lower than those of patients in Group 2. Additionally, the Tegner activity scores and IKDC scores of patients in Group 1 were also meaningfully lower than those of patients in Group 2. In Group 1 patients, there was no notable relationship observed between body mass index (BMI) and the results of the anterior drawer test (ADT) or Lachman test. However, patients with a BMI of 25 or higher in Group 1 showed a decrease in postoperative IKDC scores. In Group 2 patients, no significant relationship was identified between BMI and either the ADT or the Lachman test outcome. CONCLUSION: Based on current literature and current rehabilitation guidelines following ACL reconstruction, the decision to initiate early weight-bearing is based on a limited number of studies with low levels of evidence. In our study, we found that patients who followed a non-weight-bearing regimen for 3 weeks after surgery had better mid-term results than those who were allowed to bear weight early. It appears that further prospective studies on this topic are needed to update rehabilitation guidelines in the next.

Comparison of the biomechanical properties of grafts in three anterior cruciate ligament reconstruction techniques based on three-dimensional finite element analysis.

OBJECTIVE: To evaluate the biomechanical characteristics of grafts from three different anterior cruciate ligament (ACL) reconstructive surgeries and to determine which method is better at restoring knee joint stability. METHODS: A 31-year-old female volunteer was enrolled in the study. According to the magnetic resonance imaging of her left knee, a three-dimensional model consisting of the distal femur, proximal tibia and fibula, ACL, posterior cruciate ligament, medial collateral ligament and lateral collateral ligament was established. Then, the ACL was removed from the original model to simulate the knee joint after ACL rupture. Based on the knee joint model without the ACL, single-bundle ACL reconstruction, double-bundle ACL reconstruction, and flat-tunnel ACL reconstruction were performed. The cross-sectional diameters of the grafts were equally set as 6 mm in the three groups. The bone tissues had a Young's modulus of 17 GPa and a Poisson's ratio of 0.36. The ligaments and grafts had a Young's modulus of 390 MPa and a Poisson's ratio of 0.4. Six probes were placed in an ACL or a graft to obtain the values of the equivalent stress, maximum principal stress, and maximum shear stress. After pulling the proximal tibia with a forward force of 134 N, the distance that the tibia moved and the stress distribution in the ACL or the graft, reflected by 30 mechanical values, were measured. RESULTS: The anterior tibial translation values were similar among the three groups, with the double-bundle ACL reconstruction group performing the best, followed closely by the patellar tendon ACL reconstruction group. In terms of stress distribution, 13 out of 30 mechanical values indicated that the grafts reconstructed by flat bone tunnels had better performance than the grafts in the other groups, while 12 out of 30 showed comparable outcomes, and 5 out of 30 had worse outcomes. CONCLUSION: Compared with traditional single-bundle and double-bundle ACL reconstructions, flat-tunnel ACL reconstruction has advantages in terms of stress dispersion. Additionally, flat-tunnel ACL reconstruction falls between traditional double-bundle and single-bundle ACL reconstructions in terms of restoring knee joint stability and is superior to single-bundle ACL reconstruction.

[Early effectiveness of local injection of multimodal drug cocktail during anterior cruciate ligament reconstruction and its influence on cartilage].

Objective: To explore the early effectiveness and influence on cartilage of local injection of multimodal drug cocktail (MDC) during anterior cruciate ligament reconstruction (ACLR). Methods: Between February 2022 and August 2023, patients undergone arthroscopic ACLR using autologous hamstring tendons were selected as the study subjects. Among them, 90 patients met the selection criteria and were randomly divided into 3 groups ( n=30) according to the different injection drugs after ligament reconstruction. There was no significant difference in baseline data such as gender, age, body mass index, surgical side, disease duration, preoperative thigh circumference, and preoperative levels of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), IL-1, matrix metalloproteinase 3 (MMP-3), MMP-13, and aggrecan (ACAN) in synovial fluid between groups ( P>0.05). After the ligament reconstruction during operation, corresponding MDC (consisting of ropivacaine, tranexamic acid, and betamethasone in group A, and ropivacaine, betamethasone, and saline in group B) or saline (group C) were injected into the joint and tendon site, respectively. The length of hospital stay, postoperative tramadol injection volume, incidence of complications, degree of knee joint swelling and range of motion, visual analogue scale (VAS) score, International Knee Documentation Committee (IKDC) score, Lyshlom score, and Hospital for Special Surgery (HSS) score were recorded and compared between groups. The T2 * values in different cartilage regions were detected by MRI examination and the levels of TNF-α, IL-6, IL-1, MMP-3, MMP-13, and ACAN in synovial fluid were detected by ELISA method. Results: The patients in group A, B, and C were followed up (12.53±3.24), (13.14±2.87), and (12.82±3.32) months, respectively. All incisions healed by first intention. Compared with group C, group A and group B had shorter length of hospital stay, less tramadol injection volume, and lower incidence of complications, showing significant differences ( P<0.05); there was no significant difference between group A and group B ( P>0.05). The degree of knee swelling in group A was significantly less than that in group B and group C ( P<0.05), but there was no significant difference between group B and group C ( P>0.05). At 3, 6, 12, 24, and 48 hours after operation, VAS scores of group A and group B were significantly lower than those of group C ( P<0.05); at 72 hours after operation, there was no significant difference among the three groups ( P>0.05). At 3 days, 14 days, and 1 month after operation, the range of motion of knee joint in group A were significantly better than those in group C ( P<0.05), and there was no significant difference between the other groups ( P>0.05). At 1 month after operation, the IKDC score of group A and group B was significantly higher than that of group C ( P<0.05); there was no significant difference among the three groups at other time points ( P>0.05). There was no significant difference in Lyshlom score and HSS score among the three groups at each time point ( P>0.05). At 14 days after operation, the levels of IL-1 and IL-6 in the synovial fluid in groups A and B were significantly lower than those in group C ( P<0.05). There was no significant difference in the levels of TNF-α, MMP-3, MMP-13, and ACAN between groups A and B ( P>0.05). At 1 month after operation, there was no significant difference in the above indicators among the three groups ( P>0.05). At 3, 6, and 12 months after operation, there was no significant difference in the T2 * values of different cartilage regions among the three groups ( P>0.05). Conclusion: Injecting MDC (ropivacaine, tranexamic acid, betamethasone) into the joint and tendon site during ACLR can achieve good early effectiveness without significant impact on cartilage.

Finite element graft stress for anteromedial portal, transtibial, and hybrid transtibial femoral drillings under anterior translation and medial rotation: an exploratory study.

Stress concentration on the Anterior Cruciate Ligament Reconstruction (ACLr) for femoral drillings is crucial to understanding failures. Therefore, we described the graft stress for transtibial (TT), the anteromedial portal (AM), and hybrid transtibial (HTT) techniques during the anterior tibial translation and medial knee rotation in a finite element model. A healthy participant with a non-medical record of Anterior Cruciate Ligament rupture with regular sports practice underwent finite element analysis. We modeled TT, HTT, AM drillings, and the ACLr as hyperelastic isotropic material. The maximum Von Mises principal stresses and distributions were obtained from anterior tibial translation and medial rotation. During the anterior tibia translation, the HTT, TT, and AM drilling were 31.5 MPa, 34.6 Mpa, and 35.0 MPa, respectively. During the medial knee rotation, the AM, TT, and HTT drilling were 17.3 MPa, 20.3 Mpa, and 21.6 MPa, respectively. The stress was concentrated at the lateral aspect of ACLr,near the femoral tunnel for all techniques independent of the knee movement. Meanwhile, the AM tunnel concentrates the stress at the medial aspect of the ACLr body under medial rotation. The HTT better constrains the anterior tibia translation than AM and TT drillings, while AM does for medial knee rotation.

Presoaking Grafts in Vancomycin Does Not Impair Graft-Bone Healing in a Rat Anterior Cruciate Ligament Reconstruction Model.

BACKGROUND: The vancomycin presoaking technique (wherein grafts are treated with a vancomycin solution [VS] for anterior cruciate ligament reconstruction [ACLR]) reduces the infection rate after ACLR. However, the effects of this technique on graft-bone healing have not been fully elucidated. PURPOSE: To investigate the effects of vancomycin presoaking on graft-bone healing in a rat ACLR model. STUDY DESIGN: Controlled laboratory study. METHODS: Long flexor digitorum longus tendons were obtained from 9 Wistar rats, and each was randomly allocated to the normal saline (NS) or VS groups. The grafts were immersed in sterile saline for 30 minutes in the NS group and in a 5-mg/mL VS in the VS group. The presence of time-zero graft bacterial contamination was confirmed, and the grafts were incubated in Fluidised Thioglycollate Broth for 2 weeks. ACLR was performed on the right knees of 65 male Wistar rats using the flexor digitorum longus tendons. Each graft was similarly treated. Biomechanical testing, micro-computed tomography, and histological evaluations were performed 4 and 12 weeks postoperatively. RESULTS: The VS group showed significantly reduced graft contamination at time zero (P = .02). The mean maximum loads to failure were 13.7 ± 8.2 N and 11.6 ± 4.8 N in the NS and VS groups, respectively, at 4 weeks (P = .95); and 23.2 ± 13.2 N and 30.4 ± 18.0 N in the NS and VS groups, respectively, at 12 weeks (P = .35). Regarding micro-computed tomography, the mean bone tunnel volumes were 3.76 ± 0.48 mm3 and 4.40 ± 0.58 mm3 in the NS and VS groups, respectively, at 4 weeks (P = .41); and 3.51 ± 0.38 mm3 and 3.67 ± 0.35 mm3 in the NS and VS groups, respectively, at 12 weeks (P = .54). Histological semiquantitative examination revealed no clear between-group differences at any time point. CONCLUSION: Presoaking grafts in vancomycin in a rat ACLR model demonstrated no discernible adverse effects on short- and midterm biomechanical, radiological, and histological investigations. CLINICAL RELEVANCE: The findings provide guidance for surgeons when considering this technique.

Unanticipated mid-flight external trunk perturbation increased frontal plane ACL loading variables during sidestep cuttings.

Unanticipated trunk perturbation is commonly observed when anterior cruciate ligament (ACL) injuries occur during direction-changing manoeuvres. This study aimed to quantify the effect of mid-flight medial-lateral external trunk perturbation directions/locations on ACL loading variables during sidestep cuttings. Thirty-two recreational athletes performed sidestep cuttings under combinations of three perturbation directions (no-perturbation, ipsilateral-perturbation, and contralateral-perturbation relative to the cutting leg) and two perturbation locations (upper-trunk versus lower-trunk). The pushing perturbation was created by customised devices releasing a slam ball to contact participants near maximum jump height prior to cutting. Perturbation generally resulted in greater peak vertical ground reaction force and slower cutting velocity. Upper-trunk contralateral perturbation showed the greatest lateral trunk bending away from the travel direction, greatest peak knee flexion and abduction angles, and greatest peak internal knee adduction moments compared to other conditions. Such increased ACL loading variables were likely due to the increased lateral trunk bending and whole-body horizontal velocity away from the cutting direction caused by the contralateral perturbation act at the upper trunk. The findings may help understand the mechanisms of indirect contact ACL injuries and develop effective cutting techniques for ACL injury prevention.

Additional suture augmentation to anterior cruciate ligament reconstruction with hamstring autografts bring no benefits to clinical results, graft maturation and graft-bone interface healing.

BACKGROUND: From the perspective of graft protection and early rehabilitation during the maturation and remodeling phases of graft healing, suture augmentation (SA) for anterior cruciate ligament reconstruction (ACLR) has attracted more and more attention. STUDY DESIGN: Retrospective study. PURPOSE: To determine whether the additional SA affects clinical results, graft maturation and graft-bone interface healing during two years follow-up after ACLR. METHODS: 20 ACLRs with additional SA (ACLR-SA group) and 20 ACLRs without additional SA (ACLR group) were performed between January 2020 and December 2021 by the same surgeon and were retrospectively analyzed. Pre- and postoperative International Knee Documentation Committee (IKDC) scores, Lysholm scores, graft failure and reoperation were evaluated. The signal/noise quotient (SNQ) of autografts and the signal intensity of graft-bone interface were analyzed. All 40 patients in ACLR-SA group and ACLR group completed 2-years follow-up. RESULTS: There was no patient in the two cohorts experienced graft failure and reoperation. The postoperative IKDC and Lysholm scores have been significantly improved compared with preoperative scored in both ACLR-SA group and ACLR group, however, there was no significant difference between two groups. The SNQ of proximal graft of ACLR-SA group (14.78 ± 8.62 vs. 8.1 ± 5.5, p = 0.041) was significantly greater while the grades of graft-bone interface healing of posterior tibial was significantly lower than that of ACLR group at 1-year postoperatively (p = 0.03), respectively. There were no significant differences between the two groups of the SNQ of proximal, distal medial graft segments, and the graft-bone interface healing grades of anterior femoral, posterior femoral, anterior tibial and posterior tibial at other time points (p>0.05). CONCLUSIONS: The additional SA in ACLR had no effect on IKDC scores, Lysholm scores, graft maturation and graft-bone interface healing at 2-year postoperatively. Our research does not support the routine use of SA in ACLR.

Statistical shape analysis and computational modeling reveal novel relationships between tibiofemoral bony geometry and knee mechanics in young, female athletes.

Young female athletes participating in sports requiring rapid changes of direction are at heightened risk of suffering traumatic knee injury, especially noncontact rupture of the anterior cruciate ligament (ACL). Clinical studies have revealed that geometric features of the tibiofemoral joint are associated with increased risk of suffering noncontact ACL injury. However, the relationship between three-dimensional (3D) tibiofemoral geometry and knee mechanics in young female athletes is not well understood. We developed a statistically augmented computational modeling workflow to determine relationships between 3D geometry of the knee and tibiofemoral kinematics and ACL force in response to an applied loading sequence of compression, valgus, and anterior force, which is known to load the ACL. This workflow included 3D characterization of tibiofemoral bony geometry via principal component analysis and multibody dynamics models incorporating subject-specific knee geometries. A combination of geometric features of both the tibia and the femur that spanned all three anatomical planes was related to increased ACL force and to increased kinematic coupling (i.e., anterior, medial, and distal tibial translations and internal tibial rotation) in response to the applied loads. In contrast, a uniplanar measure of tibiofemoral geometry that is associated with ACL injury risk, sagittal plane slope of the lateral tibial plateau subchondral bone, was not related to ACL force. Thus, our workflow may aid in developing mechanics-based ACL injury screening tools for young, active females based on a unique combination of bony geometric features that are related to increased ACL loading.

Comparison of Graft Type and Fixation Method in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis Based on Randomized Control Studies.

BACKGROUND: The anterior cruciate ligament (ACL) is the most commonly injured ligament in the knee. ACL reconstruction (ACLR) proves the standard for treating this injury. However, graft choice and method of fixation remain a heavily debated topic. This study investigates the following: bone-patellar tendon-bone (BPTB) vs. hamstring tendon (HT) autograft, single-bundle vs. double-bundle hamstring graft, and metal vs. bioabsorbable screws in ACLR. METHODS: A systematic review was performed on PubMed and Google Scholar according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data were collected on patient demographics, complications, and functionality scores including International Knee Documentation Committee (IKDC) and Lysholm scores. A systematic review and meta-analysis were conducted with Review Manager. Outcome measurements were determined using forest plots with significant differences considered p < 0.05. RESULTS: Twenty-five studies were included, accounting for 2,170 patients. No statistically significant difference was appreciated when comparing BPTB to hamstring autografts. Patients who received a double bundle HT autograft exhibited significantly superior outcomes in terms of revision (p = 0.05), failure (p = 0.002), normal pivot shift tests (p = 0.04), and normal IKDC (p = 0.008). When comparing screw types, bioabsorbable screws had a greater Lysholm score (p = 0.01) and lower failure rates for copolymer screws (p = 0.03). CONCLUSION: Overall, the data collected suggested that BPTB and HT autografts display similar postoperative results. However, if an HT autograft is used, the data suggest a double-bundle graft improves both functionality and decreases the possible complications. Finally, bioabsorbable screws prove superior to metal screws when looking at both functionality and failure rates. Further research into the superior graft type is still needed. LEVEL OF EVIDENCE: Level II. See Instructions for Authors for a complete description of levels of evidence.

Functional Outcome of Arthroscopic Suture Pull-Out Fixation in Tibial Spine Avulsion of Anterior Cruciate Ligament.

BACKGROUND: Tibial spine avulsion of the anterior cruciate ligament is a rare intraarticular injury of the knee. In this condition, the tibial attachment site of the anterior cruciate ligament is detached from the knee. The mechanism of the injury is hyperextension of the knee and rotation with valgus force. There are so many treatment options. This study aims to find out the functional outcome of Arthroscopic Suture pull-out fixation in this injury. METHODS: This is a retrospective study done from August 15, 2019, to August 14, 2022. The outcome was analyzed by comparing the preoperative and 12-month postoperative International Knee Documentation Committee Score, Tegner Lysholm Score, Knee Range of motion, and Visual Analog Scale Score. RESULTS: Twenty-two patients were included with a mean age of 18.95 (13-31). Among them 15(68.2%) were male and 7(31.8%) were female. Arthroscopic suture pull-out fixation was done in all the cases. The knee range of motion was improved from preoperatively 35.00±7.86 to 135.68±3.50 at the final follow-up. The Tegner Lysholm score was improved from preoperatively 34.68±1.28 to 94.54±2.97 at the final follow-up. Preoperatively the VAS score was 8.04±1.27 which improved to 0.60±0.50 at the final follow-up. The IKDC score was 23.86±1.42 preoperatively which improved to 92.72±3.28 at the final follow-up with p-value < 0.001 Conclusions: Arthroscopic Suture pull-out fixation of tibial spine avulsion of the Anterior cruciate ligament is a good technique that restores the functions of the knee and has an excellent outcome Keywords: Anterior cruciate ligament; suture pull-out fixation; tibial spine avulsion.

[Subtuberosity anterior closing wedge osteotomy to correct the increased posterior slope of the tibial plateau]. / Subtuberositäre anterior schließende Osteotomie zur Korrektur der erhöhten posterioren Reklination des Tibiaplateaus.

OBJECTIVE: Reduction of increased reclination of the tibial plateau (posterior slope) to improve the anterior stability of the knee joint. INDICATIONS: Increased posterior reclination of the tibial plateau greater than 12° in combination with recurrent instability after anterior cruciate ligament (ACL) reconstruction. CONTRAINDICATIONS: Hyperextension of more than 15° (relative). SURGICAL TECHNIQUE: Anterior skin incision approximately 8-10 cm above the tibial tuberosity. Insertion of two converging guidewires directly below the patellar tendon ending obliquely in the area of the posterior cruciate ligament (PCL) insertion. Control of the wire position with the image intensifier core. Oscillating saw osteotomy. Removal of the wedge and closure of the osteotomy. Osteosynthesis with interfragmentary screw and medial angle-stable plate. POSTOPERATIVE MANAGEMENT: Partial load with 10-20 kg for 2 weeks, then step by step increase in load. Mobility: free. RESULTS: To date we have operated on 36 patients with recurrent instability after ACL reconstruction (20 men, 16 women, average age 34.4 years) in the manner described in this article. In 25 cases, enlarged bone tunnels were filled with allogeneic bone at the same time. The posterior slope of the tibial plateau could be reduced from an average of 14.5° to 8.8°. In 28 cases another ACL reconstruction was performed after an interval of 4-12 months. The Lysholm score significantly increased from 76.3 points to 89.2 points.

Proprioception After Primary Repair of the Anterior Cruciate Ligament.

BACKGROUND: Primary repair of the anterior cruciate ligament (ACL) has some potential advantages over the reconstruction technique, which include but are not limited to better knee sensation due to preservation of the natural ACL tissue in patients compared with tendon graft. Proprioception is impaired after ACL injuries and the sense of the joint position is lost. PURPOSE/HYPOTHESIS: The purpose of this study was to compare arthroscopic ACL primary repair and ACL reconstruction techniques clinically and functionally and analyze the differences in proprioception. It was hypothesized that primary repair would restore knee joint proprioception more successfully because the original tissue of the ACL is preserved. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 63 patients (34 underwent reconstruction and 29 underwent primary repair between 2017 and 2020) and 33 healthy controls, as well as the healthy knees of the operated groups, were evaluated between 24 and 48 months (mean, 29 months) postoperatively. Patients with proximal femoral avulsion tears and stump quality suitable for repair underwent primary repair, and those with tears outside these criteria underwent reconstruction using hamstring tendon autograft. Proprioception was evaluated using the active joint position sensation method during weightbearing, with a digital inclinometer used to measure differences between the target and achieved flexion angles of 15°, 30°, and 60°. RESULTS: At 15° of knee flexion, the deviation angles for the healthy knee of the reconstruction and primary repair groups were significantly smaller than those of the control group (P < .001), but there was no statistically significant difference between the groups in terms of deviation angle at 30° and 60° of flexion. The deviation angle of the operated knees was statistically significantly larger in the reconstruction group than in the primary repair group at all angles. The deviation angles at 15°, 30°, and 60° were 2.83°, 2.66°, and 2.66° in the reconstruction group and 1.00°, 1.00°, and 1.33° in the primary repair group, respectively (P < .001). There was no statistically significant difference between the reconstruction and primary repair groups in terms of clinical scores. CONCLUSION: Primary ACL repair can preserve proprioception in a well-selected patient group. In short-term follow-up, primary repair of the ACL in patients with proximal femoral avulsion tears and stump quality suitable for repair appears to be proprioceptively protective. Future studies are needed to clarify the long-term consequences of primary repair on proprioception in a larger population.

Computational study of extrinsic factors affecting ACL strain during single-leg jump landing.

BACKGROUND: Non-contact anterior cruciate ligament (ACL) injuries are a major concern in sport-related activities due to dynamic knee movements. There is a paucity of finite element (FE) studies that have accurately replicated the knee geometry, kinematics, and muscle forces during dynamic activities. The objective of this study was to develop and validate a knee FE model and use it to quantify the relationships between sagittal plane knee kinematics, kinetics and the resulting ACL strain. METHODS: 3D images of a cadaver knee specimen were segmented (bones, cartilage, and meniscus) and meshed to develop the FE model. Knee ligament insertion sites were defined in the FE model via experimental digitization of the specimen's ligaments. The response of the model was validated against multiple physiological knee movements using published experimental data. Single-leg jump landing motions were then simulated on the validated model with muscle forces and kinematic inputs derived from motion capture and rigid body modelling of ten participants. RESULTS: The maximum ACL strain measured with the model during jump landing was 3.5 ± 2.2%, comparable to published experimental results. Bivariate analysis showed no significant correlation between body weight, ground reaction force and sagittal plane parameters (such as joint flexion angles, joint moments, muscle forces, and joint velocity) and ACL strain. Multivariate regression analysis showed increasing trunk, hip and ankle flexion angles decreases ACL strain (R2 = 90.04%, p < 0.05). CONCLUSIONS: Soft landing decreases ACL strain and the relationship could be presented through an empirical equation. The model and the empirical relation developed in this study could be used to better predict ACL injury risk and prevention strategies during dynamic activities.