José Ricardo Pécora

Anatomy and Histology of the Knee Anterolateral Ligament

Background: Reconstruction of the anterior cruciate ligament (ACL) is one of the most common procedures in orthopaedic surgery. However, even with advances in surgical techniques and implants, some patients still have residual anterolateral rotatory laxity after reconstruction. A thorough study of the anatomy of the anterolateral region of the knee is needed. Purpose: To study the anterolateral region and determine the measurements and points of attachments of the anterolateral ligament (ALL). Study Design: Descriptive laboratory study. Methods: Dissections of the anterolateral structures of the knee were performed in 20 human cadavers. After isolating the ALL, its length, thickness, width, and points of attachments were determined. The femoral attachment of the ALL was based on the anterior-posterior and proximal-distal distances from the attachment of the lateral collateral ligament (LCL). The tibial attachment point was based on the distance from the Gerdy tubercle to the fibular head and the distance from the lateral tibial plateau. The ligaments from the first 10 dissections were sent for histological analysis. Results: The ALL was found in all 20 knees. The femoral attachment of the ALL at the lateral epicondyle averaged 3.5 mm distal and 2.2 mm anterior to the attachment of the LCL. Two distal attachments were observed: one inserts into the lateral meniscus, the other between the Gerdy tubercle and the fibular head, approximately 4.4 mm distal to the tibial articular cartilage. The mean measurements for the ligament were 37.3 mm (length), 7.4 mm (width), and 2.7 mm (thickness). The histological analysis of the ligaments revealed dense connective tissue. Conclusion: The ALL is consistently present in the anterolateral region of the knee. Its attachment to the femur is anterior and distal to the attachment of the LCL. Moving distally, it bifurcates at close to half of its length. The ALL features 2 distal attachments, one at the lateral meniscus and the other between the Gerdy tubercle and the fibular head. Clinical Relevance: The ALL may be important in maintaining normal rotatory limits of knee motion; ALL rupture could be responsible for rotatory laxity after isolated intra-articular reconstruction of the ACL.

Radiographic Landmarks for Locating the Femoral Origin and Tibial Insertion of the Knee Anterolateral Ligament

Background: Recent anatomic studies have confirmed the presence of a true ligament structure, the anterolateral ligament (ALL), in the anterolateral region of the knee. This structure is involved in the rotatory instability of the knee and might explain why some isolated reconstructions of the anterior cruciate ligament result in a residual pivot shift. Therefore, when considering the least invasive method for reconstruction of this structure, it is important to identify the corresponding bony landmarks on radiographic images. Purpose: To establish radiographic femoral and tibial landmarks for the ALL in frontal and lateral views. Study Design: Descriptive laboratory study. Methods: Ten unpaired cadaver knees were dissected. The attachments of the ALL were isolated and its anatomic parameters were quantified. Its origin and insertion were marked with a 2-mm-diameter metallic sphere, and radiographs were taken from frontal and lateral views. The obtained images were analyzed and the ALL parameters established. Results: The origin of the ALL in the lateral view was found at a point an average ± SD of 47.5% ± 4.3% from the anterior edge of the femoral condyle and about 3.7 ± 1.1 mm below the Blumensaat line. In the frontal view, the origin was about 15.8 ± 1.9 mm from the distal condyle line. The ALL insertion was an average of 53.2% ± 5.8% from the anterior edge of the lateral tibial plateau in the lateral view and 7.0 ± 0.5 mm below the lateral tibial plateau in the frontal view. In anatomic dissections, the origin of the ALL was 1.9 ± 1.4 mm anterior and 4.1 ± 1.1 mm distal to the lateral collateral ligament, and the insertion was 4.4 ± 0.8 mm below the lateral tibial plateau cartilage. Conclusion: The ALL origin on an absolute lateral radiograph of the knee is approximately 47% of the anterior-posterior size of the condyle and 3.7 mm caudal to the Blumensaat line. In a frontal radiograph, the ALL is 15.8 mm from the posterior bicondyle line. The ALL insertion is approximately 53.2% of the anterior-posterior size of the plateau in the lateral view and 7.0 mm below the articular line in the frontal view. Clinical Relevance: Knowledge of the anatomic landmarks of the ALL on radiography will permit minimally invasive surgical reconstruction with lower morbidity.

Combined Intra- and Extra-articular Reconstruction of the Anterior Cruciate Ligament: The Reconstruction of the Knee Anterolateral Ligament

We present a new technique for the combined intra- and extra-articular reconstruction of the anterior cruciate ligament. Intra-articular reconstruction is performed in an outside-in manner according to the precepts of the anatomic femoral tunnel technique. Extra-articular reconstruction is performed with the gracilis tendon while respecting the anatomic parameters of the origin and insertion points and the path described for the knee anterolateral ligament.

Evaluation of the Length and Isometric Pattern of the Anterolateral Ligament With Serial Computer Tomography

Background: Recent anatomical studies have identified the anterolateral ligament (ALL). Injury to this structure may lead to the presence of residual pivot shift in some reconstructions of the anterior cruciate ligament. The behavior of the length of this structure and its tension during range of motion has not been established and is essential when planning reconstruction. Purpose: To establish differences in the ALL length during range of knee motion. Study Design: Descriptive laboratory study. Methods: Ten unpaired cadavers were dissected. The attachments of the ALL were isolated. Its origin and insertion were marked with a 2 mm–diameter metallic sphere. Computed tomography scans were performed on the dissected parts under extension and 30°, 60°, and 90° of flexion; measurements of the distance between the 2 markers were taken at all mentioned degrees of flexion. The distances between the points were compared. Results: The mean ALL length increased with knee flexion. Its mean length at full extension and at 30°, 60°, and 90° of flexion was 37.9 ± 5.3, 39.3 ± 5.4, 40.9 ± 5.4, and 44.1 ± 6.4 mm, respectively. The mean increase in length from 0° to 30° was 3.99% ± 4.7%, from 30° to 60° was 4.20% ± 3.2%, and from 60° to 90° was 7.45% ± 4.8%. From full extension to 90° of flexion, the ligament length increased on average 16.7% ± 12.1%. From 60° to 90° of flexion, there was a significantly higher increase in the mean distance between the points compared with the flexion from 0° to 30° and from 30° to 60°. Conclusion: The ALL shows no isometric behavior during the range of motion of the knee. The ALL increases in length from full extension to 90° of flexion by 16.7%, on average. The increase in length was greater from 60° to 90° than from 0° to 30° and from 30° to 60°. The increase in length at higher degrees of flexion suggests greater tension with increasing flexion. Clinical Relevance: Knowledge of ALL behavior during the range of motion of the knee will allow for fixation (during its reconstruction) to be performed with a higher or lower tension, depending on the chosen degree of flexion.

Tradução e validação da escala Knee Society Score: KSS para a Língua Portuguesa

Objective: To translate, culturally adapt and validate the “Knee Society Score” (KSS) for the Portuguese language and determine its measurement properties, reproducibility and validity. Method: We analyzed 70 patients of both sexes, aged ages between 55 and 85 years, in a crosssectional clinical trial, with diagnosis of primary osteoarthritis, undergoing total knee arthroplasty surgery. We assessed the patients with the English version of the KSS questionnaire and after 30 minutes with the Portuguese version of the KSS questionnaire, done by a different evaluator. All the patients were assessed preoperatively, and again at three, and six months postoperatively. Results: There was no statistical difference, using Cronbach’s alpha index and the Bland-Altman graphical analysis, for the knee score during the preoperative period (p = 1), and at three months (p = 0.991) and six months postoperatively (p = 0.985). There was no statistical difference for knee function score for all three periods (p = 1.0). Conclusion: The Brazilian version of the Knee Society Score is easy to apply, as well providing as a valid and reliable instrument for measuring the knee score and function of Brazilian patients undergoing TKA. Level of Evidence: Level I - Diagnostic Studies— Investigating a Diagnostic Test - Testing of previously developed diagnostic criteria on consecutive patients (with universally applied ‘gold’ reference standard).

Simultaneous anterior cruciate ligament reconstruction and computer-assisted open-wedge high tibial osteotomy: a report of eight cases.

Eight patients, aged 37-50 years, with chronic anterior cruciate ligament (ACL) deficiency, medial compartment osteoarthritis and varus deformity underwent simultaneous arthroscopic ACL reconstruction and open-wedge high tibial osteotomy controlled by a computer navigation system. Despite preoperative planning, the surgeon may need to choose a different osteotomy site during the procedure, invalidating the previous plans. The intraoperative wire control for osteotomies is not precise. The navigation system can help obtain precise alignment during high tibial osteotomy. The average preoperative mechanical axis was 7.5 of varum (sd±1.17°), the average postoperative axis was 1.2° of valgus (sd±1.04°) (p<0.01), and the average correction of the mechanical axis was 8.7° (sd±0.76°). The site of the osteotomy was 3.9 cm (3.5-4.8 cm, sd±0.35 mm) from the articular line, with an inclination of 27.9° (24-35, sd±4.8). The simultaneous use of these procedures allowed proper correction of the knee axis during the surgery. The surgery can be performed concomitantly with ACL reconstruction.

Evaluation of the anterolateral ligament of the knee by means of magnetic resonance examination

Objective To evaluate the presence of the anterolateral ligament (ALL) of the knee in magnetic resonance imaging (MRI) examinations. Methods Thirty-three MRI examinations on patients’ knees that were done because of indications unrelated to ligament instability or trauma were evaluated. T1-weighted images in the sagittal plane and T2-weighted images with fat saturation in the axial, sagittal and coronal planes were obtained. The images were evaluated by two radiologists with experience of musculoskeletal pathological conditions. In assessing ligament visibility, we divided the analysis into three portions of the ligament: from its origin in the femur to its point of bifurcation; from the bifurcation to the meniscal insertion; and from the bifurcation to the tibial insertion. The capacity to view the ligament in each of its portions and overall was taken to be a dichotomous categorical variable (yes or no). Results The ALL was viewed with signal characteristics similar to those of the other ligament structures of the knee, with T2 hyposignal with fat saturation. The main plane in which the ligament was viewed was the coronal plane. Some portion of the ligament was viewed clearly in 27 knees (81.8%). The meniscal portion was evident in 25 knees (75.7%), the femoral portion in 23 (69.6%) and the tibial portion in 13 (39.3%). The three portions were viewed together in 11 knees (33.3%). Conclusion The anterolateral ligament of the knee is best viewed in sequences in the coronal plane. The ligament was completely characterized in 33.3% of the cases. The meniscal portion was the part most easily identified and the tibial portion was the part least encountered.

Correlation of Magnetic Resonance Imaging With Knee Anterolateral Ligament Anatomy: A Cadaveric Study.

Background: Anatomic and magnetic resonance imaging (MRI) studies have recently characterized the knee anterolateral ligament (ALL). So far, no study has focused on confirming whether the evaluated MRI parameters truly correspond with ALL anatomy. Purpose: To assess the validity of MRI in detecting the ALL using an anatomic evaluation as reference. Study Design: Descriptive laboratory study. Methods: A total of 13 cadaveric knees were subjected to MRI and then to anatomic dissection. Dissection was performed according to previous anatomic study methodology. MRIs were performed with a 0.6- to 1.5-mm slice thickness and prior saline injection. The following variables were analyzed: distance from the origin of the ALL to the origin of the lateral collateral ligament (LCL), distance from the origin of the ALL to its bifurcation point, maximum length of the ALL, distance from the tibial insertion of the ALL to the articular surface of the tibia, ALL thickness, and ALL width. The 2 sets of measurements were analyzed using the Spearman correlation coefficient (ρ) and Bland-Altman plots. Results: The ALL was clearly observed in all dissected knees and MRI scans. It originated anterior and distal to the LCL, close to the lateral epycondile center, and showed an anteroinferior path toward the tibia, inserting between the Gerdy tubercle and the fibular head, around 5 mm under the lateral plateau. The ρ values tended to increase together for all studied variables between the 2 methods, and all were statistically significant, except for thickness (P = .077). Bland-Altman plots showed a tendency toward a reduction of ALL thickness and width by MRI compared with anatomic dissection. Conclusion: MRI scanning as described can accurately assess the ALL and demonstrates characteristics similar to those seen under anatomic dissection. Clinical Relevance: MRI can accurately characterize the ALL in the anterolateral region of the knee, despite the presence of structures that might overlap and thus cause confusion when making assessments based on imaging methods.

Anatomical study on the anterolateral ligament of the knee

Objective Describe the knee anterolateral ligament (ALL) and establish its anatomical marks of origin and insertion. Methods Dissection of the anterolateral aspect of the knee was performed in six cadavers. After isolation of the ALL, its lenght, width and thickness were measured as its places of origin and insertion. The ALL origin was documented in relation to the lateral collateral ligament (LCL) origin and the insertion was documented in relation to the Gerdy tubercle, fibullar head and lateral meniscus. After the first two dissections, the ligament was removed and sent to histologycal analysis. Results The ALL was clearly identified in all knees. Its origin in the lateral epycondile was on average 0.5 mm distal and 2.5 mm anterior to the LCL. In the tibia, two insertions were observed, one in the lateral meniscus and another in the proximal tibia, about 4.5 mm distal to the articular cartilage, between the Gerdy tubercle and the fibullar head. The average measures obtained were: 35.1 mm lenght, 6.8 mm width and 2.6 mm thickness. In the ligament histological analysis, dense connective tissue was observed. Conclusion The ALL is a constant structure in the knee anterolateral region. Its origin is anterior and distal to the LCL origin. In the tibia, it has two insertions, one in the lateral meniscus and another in the proximal tibia between the Gerdy tubercle and the fibullar head.

Economic impact of treatment for surgical site infections in cases of total knee arthroplasty in a tertiary public hospital in Brazil

The aim of this study was to estimate the additional cost of treatment of a group of nosocomial infections in a tertiary public hospital. A retrospective observational cohort study was conducted by means of analyzing the medical records of 34 patients with infection after total knee arthroplasty, diagnosed in 2006 and 2007, who met the criteria for nosocomial infection according to the Centers for Disease Control and Prevention. To estimate the direct costs of treatment for these patients, the following data were gathered: length of hospital stay, laboratory tests, imaging examinations, and surgical procedures performed. Their costs were estimated from the minimum values according to the Brazilian Medical Association. The estimated cost of the antibiotics used was also obtained. The total length of stay in the ward was 976 days, at a cost of US