Drilling the Femoral Tunnel During ACL Reconstruction: Transtibial Versus Anteromedial Portal Techniques

Incorrect bone tunnel position, particularly on the femoral side, is a frequent cause of failed anterior cruciate ligament reconstruction. Several studies have reported that drilling the femoral tunnel through the anteromedial portal allows a more anatomical placement on the lateral femoral condyle and higher knee stability than does transtibial reconstruction.In the current study, the femoral tunnel was drilled with transtibial (n=6) and anteromedial (n=6) portal techniques in 12 cadaveric knees. With appropriate landmarks inserted into bone tunnels, the direction and length of the tunnels were determined on anteroposterior and lateral radiographs. Knee stability was evaluated with a KT1000 arthrometer (MEDmetric Corporation, San Diego, California) and pivot shift test, comparing the pre- and postoperative values of both techniques. Finally, all knees were dissected to enhance vision of the insertion of the reconstructed ligament. The anteromedial portal technique led to better placement of the femoral tunnel in the coronal and sagittal planes, with higher knee stability according to the pivot shift test but not the KT1000 arthrometer.Anatomical and clinical results reported in the literature on transtibial and anteromedial portal techniques are controversial, but most of studies report better results with the anteromedial portal technique, especially regarding rotational stability. The current cadaveric study showed that the anteromedial portal technique provided better tunnel placement on the lateral femoral condyle in the coronal and sagittal planes, with an improvement in the rotational stability of the knee.     

Editorial Commentary: Anteromedial Portal Drilling of the ACL Femoral Socket Avoids Transtibial Constraint Results in Anatomic Reconstruction and Superior Outcomes

Femoral and tibial tunnel locations for ACL grafts should be predicated on anatomy. Regarding femoral ACL socket or tunnel creation, multiple techniques have been debated. Network meta-analysis shows that the anteromedial portal (AMP) technique results in better anteroposterior and rotational stability than does the “standard” constrained, transtibial technique based on side-to-side differences in laxity and pivot-shift tests, as well as IKDC objective scores. The AMP provides a direct shot at the anatomic ACL origin on the femur. It avoids the osseous constraint of the reamer that hampers transtibial approaches. It avoids the extra incision required by the outside-in technique and the accompanying graft obliquity. Despite the need for knee hyperflexion and the potential for shorter femoral sockets, the AMP technique should be easily reproducible for an accomplished ACL surgeon to reproduce the patient’s anatomy.     

Comparison of Clinical Outcomes between Anteromedial and Transtibial Techniques of Single-Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

This study compared clinical outcomes obtained after single-bundle anterior cruciate ligament (ACL) reconstruction using the anteromedial (AM) and transtibial (TT) techniques, which comprise the conventional transtibial (cTT) and modified transtibial (mTT) techniques. This study included clinical randomized controlled trials and prospective and retrospective controlled trials with AM and TT techniques from the PubMed and Embase databases and the Cochrane Library. All databases were searched from January 2010 to July 2020. Two independent evaluators verified the quality of the included studies using the Cochrane Collaboration’s risk of bias tool and the Newcastle-Ottawa Scale (NOS). Outcome measures analysed included the Lachman test, pivot-shift test, side-to-side difference (SSD), Lysholm score, Tegner activity scale, International Knee Documentation Committee (IKDC) grade and score. Ten randomized controlled trials (RCTs) and 16 prospective and retrospective controlled trials were included with a total of 2202 patients. There were 1180 patients and 1022 patients in the AM and TT groups, respectively. Compared to the cTT group, superior postoperative results were observed in the AM group based on the negative rate of the Lachman test and the pivot-shift test, IKDC grade and score, Lysholm score, Tegner activity scale and SSD (p < 0.05). However, there was no significant difference between the AM and mTT groups (p > 0.05). Compared to the conventional TT technique, the AM technique exhibited superior clinical outcomes. Nevertheless, the modified TT and AM techniques had comparable results. With neither of the techniques (mTT or AM) producing significantly superior outcomes, surgeons can choose either of them depending on their preferences.Key points

• This meta-analysis was conducted based on the latest studies about the cTT, mTT and AM techniques.
• Compared to the cTT technique, the AM technique showed superior clinical outcomes.
• The mTT and AM techniques had comparable clinical outcomes.
• Surgeons can choose the one between the mTT and AM techniques, depending on their preferences.

Key words: Anterior cruciate ligament reconstruction, anteromedial, transtibial, modified transtibial, meta-analysis     

Femoral Tunnel Drilling From the Anteromedial Portal Using the Figure-4 Position in ACL Reconstruction

Creation of the femoral tunnel in anterior cruciate ligament (ACL) reconstruction via the anteromedial portal can reproducibly achieve femoral tunnel positioning at the center of the femoral ACL footprint. Anteromedial portal drilling requires knee hyperflexion, which is awkward to perform. Knee hyperflexion to 120° can easily be achieved in the figure-4 position for femoral tunnel drilling via the anteromedial portal. The leg is hyperflexed in the figure-4 position on a Mayo stand. The offset femoral guide, guidewire, and drill are placed at the femoral ACL footprint via the anteromedial portal to create the femoral tunnel.     

3D Killer Turn Angle in Transtibial Posterior Cruciate Ligament Reconstruction Is Determined by the Graft Turning Angle both in the Sagittal and Coronal Planes

ObjectiveDuring the transtibial posterior cruciate ligament (PCL) reconstruction, surgeons commonly pay more attention to the graft turning angle in the sagittal plane (GASP), but the graft turning angle in the coronal plane (GACP) is always neglected. This study hypothesized that the three‐dimensional (3D) killer turn angle was determined by both the GASP and GACP, and aimed to quantitively analyze the effects of the GASP and GACP on the 3D killer turn angle.MethodsThis was an in‐vitro computer simulation study of transtibial PCL reconstruction using 3D knee models. Patients with knee injuries who were CT scanned were selected from the CT database (April 2019 to January 2021) at a local hospital for reviewing. A total of 60 3D knees were simulated based on the knees'' CT data. The femoral and tibial PCL attachment were located on the 3D knee model using the Rhinoceros software. The tibial tunnels were simulated based on different GASP and GACP. The effects of the GASP and GACP on the 3D killer turn angle were quantitatively analyzed. One‐way analysis of variance was used to compare the outcomes in different groups. The regression analysis was performed to identify variables of the GASP and GACP which significantly affected 3D killer turn angle.ResultsThe 3D killer turn angle showed a significant proportional relationship not only with the GASP (r ² > 0.868, P < 0.001), but also with the GACP (r ² > 0.467, P < 0.001). Every 10° change of the GACP caused 2.8° to 4.4° change of the 3D killer turn angle, whereas every 10° change of the GASP caused 6.4° to 9.2° change of the 3D killer turn angle.ConclusionsThe 3D killer turn angle was significantly affected by both the GASP and GACP. During the transtibial PCL reconstruction, the proximal anterolateral tibial tunnel approach could increase the 3D killer turn angle more obviously compared with the most distal anteromedial tibial tunnel approach. To minimize the killer turn effect, both the GASP and GACP were required to be considered to increase.     

Quality of Life Following ACL Reconstruction: Baseline Predictors of Patient-Reported Outcomes

The study by Dunn et al., “Baseline Predictors of Health-Related Quality of Life after Anterior Cruciate Ligament Reconstruction: A longitudinal analysis of a multicenter cohort at two and six years,” evaluates patient factors that are predictive of outcomes following anterior cruciate ligament reconstruction. The current review critically analyzes the findings of this study in light of the current body of literature on the subject and assesses its contribution to the development of evidence-based guidelines. The authors’ primary endpoint, the Short Form-36 (SF-36), is used ubiquitously in health care research and allows their results to be compared across different disease states and studies. Despite its widespread use, the SF-36 has been shown to be sensitive to outcomes following anterior cruciate ligament reconstruction. The authors’ use of generic health-related quality of life outcome as a primary endpoint represents an important contribution to the field, and their findings allow for improved preoperative counseling by identifying baseline patient factors that predict outcomes following anterior cruciate ligament reconstruction. Furthermore, by deriving utilities from SF-36 scores, the authors are able to assess the value of anterior cruciate ligament reconstruction as compared to other medical and surgical procedures.     

关节镜下自体与同种异体肌腱重建前交叉韧带的临床对比分析

目的观察自体腘绳肌肌腱与同种异体移植物关节镜下重建膝关节前交叉韧带(ACL)的疗效与差异。方法将54例ACL损伤患者分为两组,自体腘绳肌肌腱移植组33例,男26例,女7例;年龄20～48岁。同种异体肌腱移植组21例,男16例,女5例;年龄18～52岁。均采用美国强生公司生产的Rigidfix及Intrafix系统固定,评价项目包括手术时间、发热天数、大腿周径患健侧比值、Lachman试验、中立位前抽屉试验(ADT)和国际膝关节评分委员会(IKDC)、Lysholm及Tegner评分。随访时间6～12个月,平均8个月。结果两组患者术后膝关节稳定性均得到明显好转,除手术时间外,物理检查及功能评分差异均无统计学意义(P0.05)。结论关节镜下自体及同种异体肌腱重建ACL都有较好的疗效,可根据患者的病情及主观要求灵活选择。     

三种不同移植物重建前交叉韧带的疗效分析

目的 观察及比较关节镜下自体四股半腱肌肌腱、深低温同种异体骨-腱-骨(B-PT-B)复合体、LARS人工韧带重建膝前交叉韧带(ACL)的临床疗效.方法 对55例膝ACL断裂患者行关节镜下ACL重建术,根据重建ACL的材料来源分为自体四股半腱肌肌腱组(20例)、深低温同种异体B-PT-B复合体组(20例)、LABS人工韧带组(15例),并对3组在股四头肌肌力、关节稳定性、Lysholm膝关节功能评分等方面进行对比研究.结果 术后3个月股四头肌肌力恢复情况:LARS人工韧带组较自体组、异体组恢复快,而自体组与异体组无明显差异;术后3个月膝关节稳定性:LARS人工韧带组较自体组、异体组好,自体组与异体组无明显差异,Lysholm评分:自体组(86.3±4.1)分与异体组(88.6±3.8)分无明显差异,但LARS人工韧带组(95.4±4.2)分明显高于前2组(P＜0.05).术后12个月,3组股四头肌肌力恢复情况、膝关节稳定性、功能评分差异无统计学意义(P＞0.05).结论 关节镜下同种异体韧带、LAPS人工韧带重建膝ACL疗效满意,可作为自体材料的良好替代物,但患者所承担费用较高;LARS人工韧带可在术后早期进行膝关节功能活动.