Anteromedial Tibial Attachment in Single-Bundle Anterior Cruciate Ligament Reconstruction Can Represent Normal Kinematics in Computer Simulation

Tunnel position during anterior cruciate ligament (ACL) reconstruction is considered as an important factor to restore normal knee kinematics and to gain better clinical outcomes. It is still unknown where the optimal femoral and tibial tunnel position is located in single-bundle (SB) ACL reconstruction. The purposes of this study were to analyze the knee kinematics with various graft positions and to propose the optimal graft position during SB ACL reconstruction. A musculoskeletal computer simulation was used to analyze knee kinematics. Four attachments on the femoral side (anteromedial [AM], mid, posterolateral [PL], and over-the-top positions) and three attachments on the tibial side (AM, middle, and PL positions) were determined. The middle-bundle attachment was placed at the midpoint of the AM and PL bundle attachments for the femoral and tibial attachments. SB ACL reconstruction models were constructed to combine each of the four femoral attachments with each of three tibial attachments. Kinematic comparison was made among a double-bundle (DB) model and 12 SB reconstruction models during deep knee bend and stair descent activity. The tunnel position of the tibia had greater effect of knee kinematics than that of the femur. AM tibial attachment models showed similar medial and lateral anteroposterior positions to the DB model for both activities. Axial rotation in the AM tibial attachment models was similar to the DB model regardless of the femoral attachment, whereas greater maximum axial rotation was exhibited in the PL tibial attachment models, especially during stair descent activity. AM tibial attachment can represent normal knee kinematics, whereas the PL tibial attachment can induce residual rotational instability during high-demand activities. The AM tibial tunnel is recommended for SB ACL reconstruction.

Computed tomographic evaluation of bone tunnel enlargement following single bundle anterior cruciate ligament reconstruction with hamstring autograft

<p class="abstract">The purpose of this study is to evaluate tibial and femoral tunnel diameter following single bundle anterior cruciate ligament (ACL) reconstruction and correlation between tunnel enlargement and clinical outcome. Twelve patients who underwent primary arthroscopic single bundle ACL reconstruction with hamstring graft were included in prospective case series. Preoperative clinical evaluation was performed using international knee documentation committee (IKDC) subjective score and grade, Tegner knee score and Lysholm knee score. Computed tomography (CT) evaluation of the femoral and tibial tunnels were done on post-operative day (POD) 1 and at a mean follow up of 9 months (range 7-12 months) and were compared with functional scores. Our study shows significant tibial and femoral tunnel enlargement on CT scan at 9 months (range 7-12 months) postoperatively. All the clinical evaluation scales showed improvement postoperatively. The mean average femoral tunnel diameter increased significantly (p&lt;0.001) from 8.17±0.57 to 9.08±0.660 (10%) and tibial tunnel diameter increased significantly (p&lt;0.001) from 8.08±0.669 to 9.07±0.601 (11%) postoperatively at a mean follow up of 9 months (range 7-12 months). No statistically significant difference between tunnel enlargement and clinical values were found. In our current prospective CT based study, we conclude use of extracortical fixation of femoral tunnel with stronger fixation of the tibial tunnel, tunnel orientation and anatomic fixation close to the joint line along with less aggressive rehabilitation protocol with use of extension knee brace may result in minimization of tunnel widening with quadrupled hamstring autograft.</p>

The Statistical Fragility of Single-Bundle vs Double-Bundle Autografts for ACL Reconstruction: A Systematic Review of Comparative Studies

Background: The statistical significance of a given study outcome can be liable to small changes in findings. P values are common, but imperfect statistical methods to convey significance, and inclusion of the fragility index (FI) and fragility quotient (FQ) may provide a clearer perception of statistical strength. Purpose/Hypothesis: The purpose was to examine the statistical stability of studies comparing primary single-bundle to double-bundle anterior cruciate ligament reconstruction (ACLR) utilizing autograft and independent tunnel drilling. It was hypothesized that the study findings would be vulnerable to a small number of outcome event reversals, often less than the number of patients lost to follow-up. Study Design: Systematic review; Level of evidence, 2. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the authors searched PubMed for comparative studies and randomized controlled trials (RCTs) published in select journals, based on impact factor, between 2005 and 2020. Risk-of-bias assessment and methodology scoring were conducted for the included studies. A total of 48 dichotomous outcome measures were examined for possible event reversals. The FI for each outcome was determined by the number of event reversals necessary to alter significance. The FQ was calculated by dividing the FI by the respective sample size. Results: Of the 1794 studies screened, 15 comparative studies were included for analysis; 13 studies were RCTs. Overall, the mean FI and FQ were 3.14 (IQR, 2-4) and 0.050 (IQR, 0.032-0.062), respectively. For 72.9% of outcomes, the FI was less than the number of patients lost to follow-up. Conclusion: Studies comparing single-bundle versus double-bundle ACLR may not be as statistically stable as previously thought. Comparative studies and RCTs are at substantial risk for statistical fragility, with few event reversals required to alter significance. The reversal of fewer than 4 outcome events in a treatment group can alter the statistical significance of a given result; this is commonly less than the number of patients lost to follow-up. Future comparative study analyses might consider including FI and FQ with P values in their statistical analysis.

More Conservative Rehabilitation Strategy within Postoperative 6 Month for All-Inside Reconstruction Compared with Anatomical Reconstruction of Anterior Cruciate Ligament may be able to Achieve Better Stability: Based on the Study of Graft Maturity

Background: Individualized rehabilitation based on graft maturity is necessary to optimize patient function and prevent graft re-injury. But there is a lack of studies on graft maturity in the all-inside single-bundle anterior cruciate ligament reconstruction.Hypothesis/Purpose: Compared to the difference in graft maturity, functional scores, and stability between all-inside and anatomical single-bundle anterior cruciate ligament reconstruction, it was assumed that the stability of all-inside reconstruction is relatively insufficient, and its graft maturity is worse than the anatomical reconstruction.Study Design: Randomized controlled clinical trial.Methods: Fifty-four patients were recruited in this study and randomly assigned to the all-inside reconstruction group (n = 27) and the anatomical reconstruction group (n = 27) using the same rehabilitation strategy. The Tegner, International Knee Documentation Committee, and Lysholm score were recorded at postoperative 3rd, 6th, and 12th month to assess functional recovery. Magnetic resonance imaging was conducted to measure the Signal/Noise quotient (SNQ) of the intra-articular graft to observe the maturity. Stability was assessed using GNRB relaxation measuring instrument at the postoperative 12th month.Results: The graft SNQ of the all-inside group was significantly higher than that in the anatomical group during the postoperative 6th month (p < 0.05). There was no statistical difference in graft SNQ between the two groups at postoperative 3rd and 12th month (p > 0.05). Both groups exhibited the graft’s highest SNQ in the middle region, followed by the proximal region, and the lowest was the distal region. Functional scores improved significantly in both groups and had no statistical difference (p > 0.05). The stability recovered well in both groups during the postoperative 12th month, but the GNRB relaxation was higher in the all-inside group (p < 0.05). There was no correlation between functional scores and graft maturity in the two groups (p > 0.05).Conclusions: All-inside reconstruction graft maturity is inferior to the anatomical reconstruction during postoperative 6th month, which may cause relatively insufficient stability of all-inside reconstruction compared with anatomical reconstruction under the same rehabilitation strategy. A more conservative rehabilitation strategy for all-inside reconstruction around the postoperative 6th month may achieve better stability.

Anatomic Multiple Ligament Reconstructions of the Knee

Background: Multiple ligament injuries of the knee occur in a variety of settings, often from athletic activities. Multiple cruciate and collateral ligament injuries may be associated with hamstring tendon rupture, common peroneal nerve (CPN) injury, meniscus, bone, and cartilage damage. Indications: After evaluation for concomitant life-threatening and vascular injuries (especially of the popliteal artery), the knee is assessed through a thorough physical examination and imaging series, including varus, valgus, and posterior stress radiography, and magnetic resonance imaging (MRI). Research over the last 30 years has suggested that operative treatment in the acute setting (<3 weeks) in a single-stage procedure may have improved results to delayed/staged reconstruction. Early range of motion starting on postoperative day 1 is important to prevent development of arthrofibrosis. Technique: We describe the technique used to surgically manage a patient suffering from anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and complete posterolateral corner (PLC) rupture. Neurolysis of the CPN is performed to free the irritated nerve from scar tissue, along with biceps femoris tendon and lateral capsular repairs. Anatomic-based reconstructions are performed. The ACL reconstruction is with a single bundle using a patellar tendon autograft, PCL reconstruction is a double bundle with Achilles and tibialis anterior tendon allografts, and PLC reconstruction is accomplished with a split Achilles tendon allograft. The correct orientation of tunnel placement must be planned to avoid tunnel convergence; these angles have been determined through 3D modeling. The optimal sequence for graft tensioning has been established and follows the pattern: PCL, ACL, PLC, and then medial-sided structures if necessary. Results: Successful outcomes have been reported for both medial and lateral based injuries, and follow-up studies have also shown equivalent results between acute and chronic outcomes, and for multiligament injuries involving the ACL and PCL if anatomic reconstructions with appropriate tunnel angles, passage and tensioning sequence of grafts, and rehabilitation regimens are performed. Discussion/Conclusion: Single-stage anatomic reconstruction is the gold standard for managing multiple ligament injuries in the knee. Commencement of early 0° to 90° knee range of motion and PCL-supporting bracing are critical to prevent arthrofibrosis and protect the grafts from attenuation.

Postoperative Evaluation of Knees With Posterior Cruciate Ligament Injury Using Patient-Oriented Evaluation Method: Comparison of Single-Bundle and Anatomic Double-Bundle Techniques

Introduction Using the patient-based QOL evaluation scale SF-36 and conventional assessment methods, we evaluated the postoperative outcome of patients with posterior cruciate ligament (PCL) injury who underwent single-bundle or double-bundle reconstruction, and compared the two reconstruction techniques. Methods 37 male patients with isolated PCL injury who underwent reconstruction were randomized to receive single-bundle reconstruction (group S: n=20) or double-bundle reconstruction (group D: n=17). Before surgery and 6 and 24 months after surgery, patients were evaluated by SF-36 scores, Lysholm score, visual analog scale (VAS), posterior tibial displacement rate, and knee range of motion (ROM). Results For SF-36 evaluation at 6 months post-surgery, the scores of all the subscales improved to above the national standard values in group D, whereas none of the subscale scores reached the national standard values in group S, and three subscale scores were inferior in group S compared to group D. At 24 months post-surgery, improvement of all subscale scores to above the national standard values was achieved in both groups. Lysholm score, VAS score, and posterior tibial displacement rate improved after surgery in both groups, but no significant intergroup differences were observed in all evaluation methods. For knee ROM, residual limitation of flexion was significantly more frequent in group S than in group D at 6 and 24 months post-surgery.Conclusion Arthroscopy-assisted single-bundle PCL reconstruction technique is considered to be a safe procedure with low invasiveness, but despite its widespread use, surgical result is not consistently good. This was attributed to the low reproducibility of the unique course and anatomy of PCL, and the anatomic double-bundle reconstruction technique was proposed aiming to improve treatment outcome. According to the present results, double-bundle reconstruction tended to achieve better restoration at an early stage compared to single-bundle reconstruction, with fewer patients having residual limitation of knee flexion after surgery. Trial registration number of our hospital’s IRB: 27-8.Registered 14 September 2015, retrospectively registered.

Comparative flower morphology of Agapanthus africanus and A. praecox (Amaryllidaceae)

The structure of Agapanthus africanus and A. praecox flowers was studied on permanent cross-sectional and longitudinal sections using a light microscope. The genus Agapanthus belongs to the subfamily Agapanthoideae, the family Amaryllidaceae, which is characterized by the presence of the upper ovary, septal nectaries and fruit – fleshy capsule. Micromorphological studies of the flower are considered as a way for detection of unknown plant features, adjustment of plants to specialized ways of pollination and determining the first stages of morphogenesis of fruit, and further use these features in taxonomy. 10 flowers of A. africanus and A. praecox were sectioned using standard methods of Paraplast embedding and serial sectioning at 20 micron thickness. Sections were stained with Safranin and Astra Blau and mounted in Eukitt. It was found that in the studied species the tepals have single-bundle traces. The vascular system of the superior ovary consists of a three bundle dorsal vein, of the ventral roots complex, which are reorganized into paired ventral bundles of the carpel, which form traces to ovules. For the first time, the following gynoecium zones were detected in A. africanus: a synascidiate structural zone with a height of about 560 μm and a fertile symplicate structural zone with a height of about 380 μm and a hemisymplicate zone of 2580 μm. In A. praecox gynoecium, there is a synascidiate structural zone with a height of 200 μm and a symplicate structural zone of 600 μm and a hemisymplicate zone of 620 μm. Septal nectaries appear in the hemisymplicate zone and open with nectar fissures at the base of the column, with a total septal nectar height of 2880 μm in A. africanus and 820 μm in A. praecox. The ovary roof is 300 µm in A. africanus and 200 µm in A. praecox. Triple dorsal bundles of carpels in A. africanus have been identified, which could be considered as adaptation of different stages of morphogenesis of fruit to dehiscence. The new data obtained by the vascular anatomy of the flower and the presence of different ovary zones significantly add to the information about anatomical and morphological features of the studied species, which can be further used in the taxonomy of the family Amaryllidaceae.

Double bundle ACL reconstruction leads to better restoration of knee laxity and subjective outcomes than single bundle ACL reconstruction

Purpose The purpose of this meta-analysis is to compare arthroscopic single bundle (SB) and double bundle (DB) anterior cruciate ligament (ACL) reconstructions in the light of all available randomised controlled trials (RCTs). A meta-analysis of this well-researched topic was performed and subgroup analyses of the medial portal (MP) technique and the transtibial technique (TT) were added as a new idea. The hypothesis was that the DB technique is superior to the SB technique also in subgroup analyses of the MP and TT techniques. Methods Instructions of the PRISMA checklist were followed. Systematic literature search from electronic databases, including PubMed, Cochrane library and Scopus was performed to find RCTs that compared the SB and DB techniques. Nine outcomes were used to compare these two techniques. Each study was assessed according to the Cochrane Collaboration’s risk of bias tool and three subgroup analyses (minimum 2-years’ follow-up, TT technique and MP technique) were performed. Results A total of 40 studies were included in this meta-analysis. When analysing all the included studies, the DB technique was superior to the SB technique in KT-1000/2000 evaluation (p < 0.01), IKDC subjective evaluation (p < 0.05), Lysholm scores (p = 0.02), pivot shift (p < 0.01) and IKDC objective evaluation (p = 0.02). Similar results were also found in the subgroup analyses of minimum 2-years’ follow-up and the TT technique. However, there were no differences between the two techniques in a subgroup analysis of the MP technique. Conclusion Generally, DB ACL reconstruction leads to better restoration of knee laxity and subjective outcomes than SB ACL reconstruction. The subgroup analysis of the MP technique revealed that surgeons can achieve equally as good results with both techniques when femoral tunnels are drilled through the medial portal. Level of evidence II.