Sagittal plane imaging parameters for computer-assisted fluoroscopic anterior cruciate ligament reconstruction.

Reproducible graft placement in anterior cruciate ligament (ACL) reconstructions is considered to be a critical factor affecting the successful clinical outcome of the procedure. Many current ACL instrument systems rely on intra-articular landmarks to guide the ACL tunnel placement. However, most of these instrument systems use mobile soft tissues as landmarks. We hypothesize that consistently identifiable radiographic contour landmarks can be established that can be used to improve the reproducibility of graft tunnel placement in fluoroscopically and computer-assisted ACL reconstructions. For the tibia, magnetic resonance imaging (MRI) scans showed the average ACL attachment site to be projected at 46% on a line extending from the anterior to the posterior cortices. Intraoperative fluoroscopic images were checked for the reproducibility of this line and its clinical use. For the femur, lateral radiographs demonstrated a consistent relationship between the intercondylar roof line (Blumensaat's line) and the nearly circular profile of the posterior and inferior contour of the lateral femoral condyle. The middle of this circular profile is consistently projected on Blumensaat's line at 66% of its anterior-to-posterior direction. Intraoperative images were used, which showed the aiming drill at the point of entering the lateral femoral condyle. Instead of determining the femoral attachment site relative to Blumensaat's line, we can thus determine its position relative to the center of the circle. Based on intraoperative x-rays, the proposed femoral ACL attachment site can be projected on a line parallel with the Blumensaat's line from the circle center in the posterior direction. Our results indicate that there are consistently identifiable radiographic features on the tibia and femur contours that can be used for fluoroscopic and computer-assisted guidance of ACL graft placement.     

X线影像导航系统辅助关节镜下前交叉韧带重建术

目的 探讨X线影像导航系统辅助关节镜下前交叉韧带重建手术的可行性和隧道位置的精确性。方法 2005年12月至2006年2月共行X线影像导航系统辅助前交叉韧带重建手术30例（导航手术组）,同期使用传统关节镜手术技术重建前交叉韧带40例（传统手术组）,术前进行股骨、胫骨隧道理想位置的设计。术中C臂透视机获得正侧位影像后传输入计算机系统形成虚拟工作界面。膝关节周围分别固定股骨、胫骨追踪器。手术工具装配追踪器。经过注册及校准后,导航系统通过捕获追踪器发射的信号实时跟踪手术工具的位置方向,并叠加在工作界面上,达到导航的目的。本文对导航手术组进行总结,术后进行胫骨隧道位置测量,并与传统手术组进行比较。结果术后测量,导航手术组胫骨隧道位置平均值45．90％（41．00％～49．80％,标准差2．36％）,传统手术组胫骨隧道位置在41．05％（范围25．00％～54．00％,标准差6．01％）,两组结果差异有统计学意义（P〈0．05）。同时导航组的平均手术时间较传统组延长20min,透视次数为4次。术后短期随访（1-3个月）,两组膝关节稳定性无明显差异。结论 X线影像导航系统辅助关节镜下前交叉韧带重建手术是安全、可行的,通过术前规划,可以使股骨、胫骨隧道位置更精确。     

Endoscopic anterior cruciate ligament reconstruction using a four strand hamstring tendon construct

Disruption of the anterior cruciate ligament (ACL) may result in recurrent episodes of giving way of the knee with the risk of concomitant damage to the menisci and chondral surfaces. Surgical reconstruction for ACL ligament deficiency is aimed at restoring normal knee kinematics, thereby, allowing for return to pre-injury function. Endoscopic reconstruction of the ACL using a four-strand tendon autograft is a well documented, prospectively evaluated methodology. This article outlines the authors' technique and identifies key points of the surgical procedure.     

计算机导航关节镜下前十字韧带重建术

目的介绍计算机导航技术辅助关节镜下前十字韧带重建术的术前规划和手术方法,比较导航技术辅助与单纯关节镜技术中股骨、胫骨隧道位置的优良率。方法根据术前标准正侧位X线片设计股骨、胫骨隧道的理想位置。术中“C”型臂X线机获得正侧位影像后输入计算机,形成虚拟工作界面。膝关节周围分别于股骨、胫骨侧安置“患者追踪器”。前十字韧带胫骨及股骨导向器上分别装配“工具追踪器”。经过注册及校准后,导航系统识别并捕获上述追踪器发射的信号,确定膝关节的位置,实时跟踪手术工具的位置和方向,并将隧道的虚拟路径叠加在工作界面上,供术者实时调整导向器的位置与方向,直至达到术前规划的要求。临床上完成计算机导航关节镜下前十字韧带重建术46例。对其中40例进行术后X线片测量,确定胫骨及股骨隧道的位置,并与同期进行的40例单纯关节镜下重建术隧道位置的测量结果进行比较。结果导航组胫骨隧道位置平均为45.35%±3.827%(37%￣53%),股骨隧道位置平均为62.25%±5.610%(52%￣73%);关节镜组胫骨隧道位置平均为41.05%±6.008%(25%～54%),股骨隧道位置平均为56.62%±7.316%(46%￣77%)。导航组的股骨及胫骨隧道位置较关节镜组偏后,差异有统计学意义(P<0.05),导航组的标准差小于关节镜组。结论计算机导航技术可以使关节镜下前十字韧带重建手术中胫骨及股骨隧道的位置更偏后,提高了手术准确性及可重复性。     

Two-dimensional fluoroscopic navigation in posterior cruciate ligament reconstruction: a preclinical cadaver study

Objectives  

To assess the feasibility and accuracy of frameless stereotactic two-dimensional fluoroscopy-assisted guide pin (GP) placement in posterior cruciate ligament (PCL) reconstruction in human cadavers.     

Accurate placement of bone tunnels in reconstruction of the anterior cruciate ligament - a contribution of computer-assisted navigation

Rupture of the anterior cruciate ligament (ACL) is one of the most frequent injuries to the knee joint in the young. ACL repair is a major orthopedic procedure most often performed in the younger adult population. Early stabilization of the knee joint by ACL reconstruction also decreases the risk of injury to other important structures. At ACL reconstruction, the biggest problem is usually the exact placement of drilled tunnels. This significantly affects the outcome of surgery, i. e., range of motion, knee joint stability, reaction of the synovium in the knee, pain, impingement and potential graft failure with lesion development. However, 70 % of ACL reconstructions are carried out by orthopedic surgeons whose experience is limited to less than 20 ACL repair procedures in a year! Arthroscopy does not allow the surgeon to gain a complete 3D view of important anatomical structures, particularly in the anteroposterior direction. Computer-assisted navigation systems should aid in minimizing these problems. First reports on the use of computer-assisted navigation in ACL reconstruction, which have already been published in the international literature, have provided clear evidence that more exact bone tunnel placement can be achieved with navigation than with the use of conventional techniques. In addition, kinematic navigation enables us to measure anteroposterior and rotational knee stability, isometry, impingement and the angles of bone tunnel placement. It permits a choice from various types of graft. Last but not least, kinematic navigation provides a tool for recording surgery outcomes without a necessity to use further examination methods. Its drawbacks, namely, the learning curve, additional fixation of navigation probes to the femur and tibia and slightly longer operative time, should be considered in the context of presumed long-term benefits for the patient.     

Endoscopic anterior cruciate ligament reconstruction with patella tendon autograft

The patella tendon is the most commonly used graft source for ACL reconstruction because of its biomechanical strength and stiffness, the availability of bone-to-bone healing on either end, and the ability to firmly secure the graft within the tunnels. Consistently good results have been reported in the literature, with expectations to return to all activities at pre-injury levels of performance. We outline our technique for endoscopic ACL reconstruction using a patella tendon autograft. The technique is divided into the critical stages of pre-operative assessment, graft harvest, notch preparation, tunnel placement, graft passage, graft fixation, and rehabilitation. Methods for avoiding pitfalls and overcoming mishaps are described.     

关节镜下LARS人工韧带重建前交叉韧带

膝关节前交叉韧带（anterior cruciate ligament，ACL）损伤后自愈能力差，移植重建是目前治疗的主要手段。常用的移植物有很多种，其中最常用的是自体髌韧带和半腱肌腱，但供区并发症问题一直影响最终疗效。我院2006年6～12月采用法国产LARS（1igament advancement reinforcement system）人工韧带进行关节镜下ACL重建21例，效果满意，现报告如下。[第一段]     

Application of a computerised navigation technique to assist arthroscopic anterior cruciate ligament reconstruction

Purpose

Based on biomechanical cadaver studies, anatomical double-bundle reconstruction of the anterior cruciate ligament (ACL) was introduced to achieve better stability in the knee, particularly in respect of rotatory loads. Previously, the success of ACL reconstruction was believed to be mainly dependent on correct positioning of the graft, irrespective of the number of bundles for which computer-assisted surgery was developed to avoid malpositioning of the tunnel. The aim of this study was to compare rotational and translational stability after computer-navigated standard single-bundle and anatomical double-bundle ACL reconstruction.

Methods

The authors investigated 42 consecutive patients who had undergone the single-bundle or double-bundle ACL reconstruction procedure using autogenous hamstring tendon grafts and ENDOBUTTON fixation in patients who had been followed up for a minimum of 24 months. Post-operative anteroposterior and rotational laxity was measured with the KT3000 and compared between groups.

Results

Both surgical procedures significantly improve rotational and translational stability compared to the preoperative ACL-deficient knee (P<0.05). No significant differences were registered between groups with regard to anteroposterior displacement of the tibia. The International Knee Documentation Committee (IKDC) and Lysholm scores were significantly higher in the double-bundle group. However, the results were excellent in both groups.

Conclusions

The use of computer-assisted ACL reconstruction, which is a highly accurate method of graft placement, could be useful for inexperienced surgeons to avoid malposition. Long-term results of at least five years are needed to determine whether double-bundle ACL reconstruction, which was associated with improved rotational laxity and significantly better IKDC and Lysholm scores compared to the standard single-bundle ACL reconstruction procedure, exerts an influence in terms of avoiding osteoarthritis or meniscus degeneration.     

Revision anterior cruciate ligament reconstruction

Revision ACL surgery is indicated in patients who present with pathologic anterior laxity on clinical examination that reproduces their symptoms of instability during activities of daily living or athletic activities. The goals of the revision ACL surgery are to stabilize the knee, prevent further injury to the articular cartilage and menisci, and maximize the patient's function. Successful revision ACL surgery requires a thorough preoperative evaluation, including a detailed history, physical examination, and radiographic evaluation. Preoperative planning begins with a determination of the mechanisms of failure for the initial ACL reconstruction. Often a primary, as well as secondary cause, for failure can be identified. The determination of the cause of failure is the first step in a carefully-constructed treatment plan, which includes consideration of skin incisions to be used, method of graft removal, hardware removal, the need for a staged procedure or concomitant surgery, graft material selection, tunnel placement, graft fixation, and postoperative rehabilitation protocol. Despite the most meticulous planning, unanticipated findings may be encountered in the operating room, and the preoperative plan should have enough flexibility to accommodate these developments. Finally, it is crucial to counsel the patient preoperatively to limit his or her expectations regarding their surgical outcome. Given the complexity of revision ACL reconstruction, patient expectations must be adjusted to realistically match the potential for success. With proper planning, attention to detail, and appropriate patient expectations, revision ACL surgery can result in a beneficial and satisfying patient outcome.     

Osteoarthritis after anterior cruciate ligament reconstruction using a patellar tendon autograft

We studied 58 knees that underwent anterior cruciate ligament (ACL) reconstruction using a patella tendon autograft. The mean age at reconstruction was 30.4 (18–58) years, and the average follow-up was 11.2 (8.6–13.8) years. The presence of osteoarthritis was assessed radiographically using Kellgren and Lawrence’s classification. Osteoarthritis was detected in the medial compartment in 25 cases and in the lateral compartment in 14 cases. Significant independent predictors of osteoarthritis were: accompanying meniscal injury [odds ratio (OR) 9.19), p<0.001], an interval of more than 6 months from injury to reconstruction (OR 4.77, p=0.021), and age more than 25 years at reconstruction (OR 3.37, p=0.034). However, no statistically significant correlation was found between the development of osteoarthritis and clinical outcome or radiological stability.

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Résumé Nous avons étudié 58 genoux qui ont subi reconstruction du ligament croisé antérieur par une autogreffe du tendon rotulien. L’âge moyen à la reconstruction était de 30,4 (18–58) ans, et le suivi moyen était de 11,2 (8.6–13.8) ans. La présence d’arthrose a été controlée radiographiquement en utilisant la classification de Kellgren et Lawrence. L’arthrose a été détectée dans le compartiment médial dans 25 cas, et dans le compartiment latéral dans 14 cas. Les éléments indépendants prédictifs de l’arthrose étaient: la lésion méniscale associée, un intervalle de plus de 6 mois entre le traumatisme et la reconstruction, et l’âge supérieur à 25 ans à la reconstruction. Cependant, aucune corrélation statistiquement significative n’a été trouvée entre le développement de l’arthrose et le résultat clinique ou la stabilité radiologique.

     

Tourniquet used in anterior cruciate ligament reconstruction: a system review

Purpose

To identify whether routine use of a tourniquet is a better choice for anterior cruciate ligament reconstruction.

Method

We searched Amed, British Nursing Index, Embase, Pubmed, Scopus, Cochrane Library and Google Scholar. We used revised Jadad score to evaluate the trial quality. Each reference list was viewed for any ignored studies. Two reviews independently extracted data from all eligible trials, including study design, patients’ characteristics, interventions and outcomes. The available data were using random effects models with mean differences for continuous variables.

Results

The only meta-analysis indicated there was no significant difference in operative time between the tourniquet and non-tourniquet groups (mean differences ?5.71, 95 % CI ?12.40, 0.99). The remaining outcomes had variations in the outcome measures, so it was not possible to perform meta-analysis.

Conclusions

There was insufficient evidence to support the hypothesis that patients would benefit from routinely applying a tourniquet. More high-quality randomized controlled trials were needed to test the result.     

Rehabilitation after anterior cruciate ligament reconstruction

The "Frankfurt rehabilitation regimen" following anterior cruciate ligament reconstruction is presented. ACL rehabilitation is discussed in the light of knowledge on knee biomechanics and proprioception as well as clinical results of reconstruction. Special emphasis is given to exercise therapy.     

Anatomic double-bundle anterior cruciate ligament reconstruction

Objective: To retrospectively evaluate the early results of anatomic double-bundle anterior cruciate ligament (ACL) reconstruction and compare with the results of native ACL of the contralateral knee.M...     

Biomechanics and anterior cruciate ligament reconstruction

For years, bioengineers and orthopaedic surgeons have applied the principles of mechanics to gain valuable information about the complex function of the anterior cruciate ligament (ACL). The results of these investigations have provided scientific data for surgeons to improve methods of ACL reconstruction and postoperative rehabilitation. This review paper will present specific examples of how the field of biomechanics has impacted the evolution of ACL research. The anatomy and biomechanics of the ACL as well as the discovery of new tools in ACL-related biomechanical study are first introduced. Some important factors affecting the surgical outcome of ACL reconstruction, including graft selection, tunnel placement, initial graft tension, graft fixation, graft tunnel motion and healing, are then discussed. The scientific basis for the new surgical procedure, i.e., anatomic double bundle ACL reconstruction, designed to regain rotatory stability of the knee, is presented. To conclude, the future role of biomechanics in gaining valuable in-vivo data that can further advance the understanding of the ACL and ACL graft function in order to improve the patient outcome following ACL reconstruction is suggested.