Anteromedial Bundle Of Anterior Cruciate Ligament Research Articles

Comparison of Synovialization and Clinical Outcomes between Anterior Cruciate Ligament Anteromedial Bundle Augmentation and Double-Bundle Anterior Cruciate Ligament Reconstruction.

This study aimed to compare clinical outcomes and second-look arthroscopic findings between double-bundle anterior cruciate ligament (ACL) reconstruction for complete ACL rupture and anteromedial (AM) bundle augmentation with preservation of the posterolateral (PL) bundle in isolated AM bundle rupture. Between 2014 and 2021, we retrospectively analyzed 95 ACL reconstructions with at least 2 years of follow-up. Patients undergoing primary ACL reconstruction from January 2014 to June 2021 were included in the study. Double-bundle ACL reconstruction (group 1) was performed in the cases involving male patients, high activity levels, age below 40 years, or when there was a patient preference for double-bundle reconstruction. In contrast, for partial ACL ruptures with an intact PL bundle confirmed on preoperative magnetic resonance imaging, AM augmentation was performed (group 2). Preoperative and final follow-up clinical outcomes, along with synovial coverage during second-look arthroscopy, were compared between group 1 (65 cases) and group 2 (30 cases). Statistical analysis included correlation coefficients between the groups. The Lysholm score, Tegner activity scores, and International Knee Documentation Committee (IKDC) knee evaluation form score at final follow-up were 81.8 (±5.5), 7.2 (±0.9), and 79.4 (±6.7), respectively, in group 1, and they were 88.0 (±6.4, p = 0.038), 7.9 (±0.5, p = 0.042), and 86.2 (±5.4, p = 0.081), respectively, in group 2. For group 1, the Lachman test (p = 0.093) and the pivot shift test (p = 0.176) at the final follow-up showed no laxity in 57 and 59 knees, and there was plus one laxity in 8 and 6 knees. For group 2, there were no laxity in 27 and 28 knees, and plus one laxity in 3 and 2 knees. Synovial coverage area percentages of the grafted tendon were 74.3 (±10.7) and 86.9 (±7.3, p = 0.002) in groups and group 2, respectively, with superior synovial coverage observed in group 2. The AM bundle augmentation with preservation of the PL bundle in ACL injury yielded better synovial coverage and clinical scores compared with double-bundle ACL reconstruction for complete ACL rupture.

Neo-Natal Castration Leads to Subtle Differences in Porcine Anterior Cruciate Ligament Morphology and Function in Adolescence.

Female adolescent athletes are at a higher risk of tearing their anterior cruciate ligament (ACL) than male counterparts. While most work related to hormones has focused on the effects of estrogen to understand the increased risk of ACL injury, there are other understudied factors, including testosterone. The purpose of this study was to determine how surgical castration in the male porcine model influences ACL size and function across skeletal growth. Thirty-six male Yorkshire crossbreed pigs were raised to 3 (juvenile), 4.5 (early adolescent), and 6 months (adolescent) of age. Animals were either castrated (barrows) within 2 weeks after birth or were left intact (boars). Posteuthanasia, joint and ACL size were assessed via MRI, and biomechanics were assessed via a robotic testing system. Joint size increased throughout age, yet barrows had smaller joints than boars. ACL cross-sectional area (CSA), length, volume, and in situ stiffness increased with age, as did the percent contribution of the ACL anteromedial (AM) bundle to resisting loads. Boar ACL, AM bundle, and PL bundle volumes were 19%, 25%, and 15% larger than barrows across ages. However, ACL CSA, in situ stiffness, and bundle contribution were similar between boars and barrows. The barrows had smaller temporal increases in AM bundle function than boars, but these data were highly variable. Early and sustained loss in testosterone leads to subtle differences in ACL morphology but may not influence measures associated with increased injury risk, such as CSA or bundle forces in response to applied loads.

Single-Bundle Augmentation for a Partial Tear of the Anterior Cruciate Ligament

Given the prevalence of anterior cruciate ligament (ACL) tears in young athletes, it is essential to elucidate and illustrate surgical interventions that return the most favorable outcomes. Although most ACL injuries are full-thickness tears, occasionally either the anteromedial (AM) or posterolateral (PL) bundle is torn in isolation, allowing consideration of an ACL reconstruction or augmentation. Because the ACL-deficient knee has been shown to exhibit less proprioceptive feedback, the preservation of the intact bundle may offer an inherent component of stability. After arthroscopy has confirmed a partial ACL tear, the decision to augment the intact bundle can be made. The technique is adapted from principles of the double-bundle reconstruction such that the graft follows the path of either the native AM bundle or the native PL bundle, depending on the location of the partial tear. We present our surgical technique for ACL AM bundle augmentation with PL bundle reconstruction using a semitendinosus tendon autograft.

Length Difference of Anteromedial and Posterolateral Bundles of Anterior Cruciate Ligament in Flexion and Extension (Cadaver Study)

We aimed to measure lengths of both anteromedial (AM) and posterolateral (PL) bundles of anterior cruciate ligament (ACL) in flexion and extension, and analyse statistically. 20 knees of 10 human cadavers were studied in Republic of Turkey Ministry Of Justice Forensic Medicine Institute. All the subjects were male (100%). An anterior longitudinal incision was made and After passing subcutaneous tissue, knee joint was visualized with a medial parapatellar approach. Lengths of both AM and PL bundles of ACL in flexion and extension were measured in millimetres with flexible ruler scale. Data was analysed statistically. Wilcoxon test was used for statistical analysis. Mean age was 46.5 (32-62). A statistically significant difference was seen in lengths of both AM and PL bundles of ACL in flexion and extension (p<0.05). Difference in lengths of bundles of AM and PL in flexion and extension is statistically significant. Whereas, any statistical difference was not noted in comparison of length differences among bundles during flexion and extension (z=0.085, p=0.932). Difference in lengths’ of bundles of AM and PL in flexion and extension was seen statistically significant in our study. In single-bundle technique, only AM bundle of ACL is reconstructed. Besides, both AM and PL bundles of ACL are reconstructed in double-bundle technique. AM and PL bundles have distinct features and lengths in different flexion degrees. We emphasize to review this entity while determining reconstruction technique for ACL-deficient patients.

Arthroscopic single bundle reconstruction of the ruptured anteromedial bundle of anterior cruciate ligament

ObjectiveTo explore the surgical techniques and therapeutic effects of arthroscopic reconstruction of the ruptured anteromedial bundle of anterior cruciate ligament (ACL).MethodsFrom May 2004 to May 2010, 293 patients received arthroscopic ACL reconstruction at our department. Of them,40 cases (13.7％ ) were diagnosed as anteromedial bundle rupture of ACL during arthroscopic exploration.The ruptured anteromedial bundle was reconstructed using the autologous quadrupled hamstring graft while the posterolateral bundle was preserved during the procedure. Lysholm scoring and Lachman test were performed prior to and after the reconstruction to evaluate functional recovery of the knee. The proprioceptive function of the knee was evaluated by Threshold to Detection of Passive Motion (TDPM) system.ResultsAll the cases of ruptured anteromedial bundle were followed up for an average of 33 months (from 7 to 56 months).The average Lysholm score was 56.7 ± 8.6 before surgery and 92. 0 ± 5.0 at the last follow-up, with a significant difference ( t =27. 750, P =0. 000). By Lysholm scoring at the last follow-up, 19 patients were rated as excellent, 16 as good, 5 as fair and none as poor, with an excellent-to-good rate of 87. 5％. By the Lachman test, 34 patients were negative, 4 weakly positive and 2 positive. At the last follow-up, there was no significant difference between the average TDPM of the affected knees (2. 12° ±- 0. 15°) and that of the contralateral knees (2. 09° ±0. 16°) (t =0. 657, P =0. 515) . All the patients resumed normal activities after surgery with obviously improved stability of the knee.ConclusionArthroscopic reconstruction of the ruptured anteromedial bundle of ACL with preservation of the posterolateral bundle can help precise positioning of the bone tunnel, provide additional mechanical strength for graft fixation, and accelerate revascularization and sensory reinnervation of the reconstructed ACL. Key words: Anterior cruciate ligament; Arthroscopy; Anteromedial bundle

The Ability of 3 Different Approaches to Restore the Anatomic Anteromedial Bundle Femoral Insertion Site During Anatomic Anterior Cruciate Ligament Reconstruction

The purpose of this study was to determine whether drilling the femoral tunnel when performing anterior cruciate ligament (ACL) reconstruction through the accessory medial portal, as opposed to drilling the tunnel transtibially, will lead to more frequent location of the anteromedial femoral tunnel within the anatomic anteromedial bundle insertion site. Primary anatomic double-bundle reconstruction was performed on 113 patients. Intraoperatively, we placed a guide pin through the anteromedial and posterolateral tibial tunnels and accessory medial portal, attempting to reach the center of the native femoral anteromedial bundle insertion. For each approach, the position of the guide pin was classified as (1) within the center of, (2) off-center within, or (3) outside of the femoral anteromedial insertion. There were significant differences in the ability of each approach to reach the center of the femoral anteromedial bundle insertion. Through the tibial anteromedial tunnel, the femoral anteromedial insertion center was reached in 4.4% of cases, whereas it was off-center within and outside of the femoral anteromedial insertion in 23.0% and 72.6%, respectively. Through the tibial posterolateral tunnel, the femoral anteromedial insertion center was reached in 60.2% of cases, whereas it was off-center within and outside of the femoral anteromedial insertion in 23.9% and 15.9% of cases, respectively. When approached from the accessory medial portal, the center of the femoral anteromedial insertion was reached in 100% of the cases. Ultimately, the femoral anteromedial tunnel was drilled through the tibial anteromedial tunnel in 0.9%, through the posterolateral tunnel in 62.8%, and through the accessory medial portal in 36.3% of cases. Drilling the femoral tunnel for the anteromedial graft through the accessory medial portal, as opposed to drilling the tunnel transtibially, leads to more frequent location of the anteromedial femoral tunnel within the anterior cruciate ligament anteromedial bundle anatomic footprint.

On the viscoelastic properties of the anteromedial bundle of the anterior cruciate ligament

The nonlinear viscoelastic properties of the anteromedial (AM) bundle of porcine anterior cruciate ligament (ACL) were characterized by using a new analytical approach based on the quasi-linear viscoelastic theory. Stress relaxation and cyclic tensile tests were performed. Using the solution derived from this approach, we curve-fitted data from the stress relaxation test to determine the viscoelastic coefficients for the ligament bundles. The coefficients were verified by comparison of the predicted and the experimental results from the cyclic tensile test. The ACL AM bundle exhibited significant stress relaxation with time; a reduction of more than 50% of the peak value occurred during the 2-h experiment. Also, the reduced relaxation function for the ACL AM bundle was not a linear function of logarithmic time, as is commonly assumed for many soft tissues. The new approach, which takes into account the finite strain rate of the ramp function used in the stress relaxation test, provides an accurate description of this nonlinear stress relaxation behavior.