PURPOSE: This research aims at developing a simulation system for training of the correct placement of isometric points in arthroscopic reconstruction of anterior cruciate ligaments, using personal computer-based software and rapid prototyping knee models. MATERIALS AND METHODS: CT scan images of the knee joints of thirteen patients were used. Simulation software was developed on V-works(Clinic3D Inc.), a three-dimensional medical imaging system. Rapid prototyping models were made of hardened starch with a 0.178 mm slice thickness. RESULTS: In the first phase, trainee surgeons can study the positions of the bony attachments of healthy anterior cruciate ligaments, and compare their multiplanar reformatting images and a three-dimensional computer model of the bones. In the second phase, trainee sur-geons can place isometric points on the three-dimensional computer models and compare the results with the points set by a supervis-ing surgeon. Finally, rapid prototyping models, which are almost identical to the actual bones, are produced to allow the trainees to observe the isometric points marked on the models. CONCLUSION: Our system can provide a patient-specific simulation environment for beginners at arthroscopic anterior cruciate ligament reconstruction. It can be used as an educational and training tool for locating the isometric point of the anterior cruciate ligament during an operation.
Anterior Cruciate Ligament Reconstruction ; Anterior Cruciate Ligament* ; Computer Simulation* ; Diagnostic Imaging ; Humans ; Knee ; Knee Joint ; Starch ; Tomography, X-Ray Computed

Background: Nowadays, the anterior cruciate ligament (ACL) injury has been one of the most common diseases of the knee joint. The relationships between the ACL injury and the anatomical structures are still controversial. This study aimed to identify the anatomical risk factors of ACL injury by magnetic resonance imaging (MRI) of the knee. Methods: This was a retrospective study of 125 patients undergoing primary ACL reconstruction between July 2013 and May 2017. Another 125 patients without any organic knee joint injury were served as controls. The shape of intercondylar notch, the intercondylar notch width index, the intercondylar notch height index, the α angle, the β angle, and the medial and lateral tibial plateau slope were measured with MRI and compared. The data were compared by binary logistic regression to find the risk factors. Results: The two groups differed in the proportion of male patients (70.4% vs. 52.0%, χ = 8.911, P = 0.003), but gender was excluded as a risk factor for ACL injury with regression analysis (odds ratio = 1.476, 95% confidence interval [CI]: 0.689-3.160, P = 0.317). The injured group was found to have a smaller notch width index (95% CI = 7.960E-23-2.154E-9, P < 0.001), a larger β angle (95% CI = 1.311-1.785, P < 0.001), and a larger lateral tibial plateau slope (95% CI = 1.201-1.683, P < 0.001). The cutoff values of notch width index, β angle, and the lateral tibial plateau slope were 0.252, 38.5°, and 7.5°, respectively. Conclusions: In this study, a narrow intercondylar notch (intercondylar notch width index <0.252), a larger lateral tibial slope (>7.5°), and larger β angle (>38.5°) might be the factors associated with ACL injury. Trial Registration ChiCTR-RRC-17014116; http://www.chictr.org.cn/showproj.aspx?proj=24119.
Adult ; Anterior Cruciate Ligament Injuries ; diagnostic imaging ; etiology ; Anterior Cruciate Ligament Reconstruction ; Female ; Humans ; Knee Joint ; diagnostic imaging ; Logistic Models ; Magnetic Resonance Imaging ; Male ; Retrospective Studies ; Risk Factors

This study evaluated the clinical value of three-dimensional computed tomography (3D-CT) images in the knees following arthroscopic anterior cruciate ligament (ACL) reconstruction. Sixty-five consecutive patients underwent arthroscopic ACL reconstruction with single-incision and single-tunnel techniques. Preoperative and postoperative (12 months in between) clinical evaluation were performed using the Lysholm knee score and a KT-1000 arthrometer (side to side). Computed tomography (CT) of the knees was performed in a week after operation in all cases and at mean follow-up of 12 months. All of the clinical evaluation scales performed showed an overall improvement. 3D-CT images can display not only the bone tunnels of the knees including femoral and tibia very distinctly, but also the contour of the reconstructed ACL including adjacent structures. The average femoral tunnel diameter increased significantly (3%) from (9.15 +/- 0.03) mm postoperatively to (9.48 +/- 0.5) mm after 12 months; tibial tunnel increased significantly (12%) from (9.11 +/- 0.09) mm to (10.2 +/- 0.3) mm. There was no statistical difference between tunnel enlargements. So multi-slices spiral CT can evaluate the contour and changes of contour and changes of the knee after ACL reconstruction, which will be helpful in the intraoperative location and postoperative assessment of the knees.
Adult ; Anterior Cruciate Ligament ; diagnostic imaging ; surgery ; Anterior Cruciate Ligament Injuries ; Anterior Cruciate Ligament Reconstruction ; methods ; Arthroscopy ; Female ; Humans ; Imaging, Three-Dimensional ; Knee Injuries ; diagnostic imaging ; surgery ; Male ; Middle Aged ; Postoperative Period ; Tomography, X-Ray Computed ; methods ; Young Adult

OBJECTIVE: To investigate the correlation between the quadriceps cross-sectional area (CSA) and quadriceps muscle volume (QMV) at different horizontal levels from the upper edge of the patella, and to determine the best observation position. METHODS: Thigh magnetic resonance imaging (MRI) images of 22 Chinese young men [age: (29±6) years] with anterior cruciate ligament (ACL) rupture were examined. The CSA was measured at 18, 15, and 12 cm above the upper edge of the pate-lla (denoted by CSA-18, CSA-15 and CSA-12 respectively), and the QMV and CSA were determined by semiautomatic segmentation. A curve model was established to estimate QMV. Bland-Altman analysis was performed to determine the confidence limits of the volumes. RESULTS: On the unaffected side, the mean QMV was (1 944.45±323.77) cm³. The quadriceps CSA at the upper edge of the patella at 18, 15, and 12 cm was (80.80±12.16) cm², (77.53±12.03) cm², and (72.68±10.51) cm², respectively. The coefficients of determination (R²), ascertained using curve estimation models, for the 3 positions were 0.819, 0.755, and 0.684 (P < 0.001), and the standard deviations of the volume estimated value (SEE) were 7.4%, 8.7%, and 9.8%. The fitting equations of the three horizontal positions were all good, but the fitting degree of CSA-18 was the highest. The Bland-Altman scatter plot showed that the arithmetic means of the QMV at 18, 15 and 12 cm from the upper edge of the patella 0.8 cm³, -1.1 cm³, and 0.9 cm³ and 95% limits of agreement (LoA) were (-268.8, 270.5), (-315.2, 313.1), and (-355.7, 357.5), respectively. The estimated QMV was in good agreement with the measured value. The difference between the estimated CSA-18 and measured values was the smallest. The results on the affected side were consistent. CONCLUSION The correlation between QMV and CSA in the young men with the upper edge of patella as baseline was reliable and consistent. Among them, CSA-18 had the highest correlation with the QMV. However, different observation sites could be selected for different injuries of the quadriceps.
Adult ; Anterior Cruciate Ligament Injuries/surgery* ; Anterior Cruciate Ligament Reconstruction ; Humans ; Magnetic Resonance Imaging ; Male ; Patella ; Quadriceps Muscle/diagnostic imaging* ; Young Adult

OBJECTIVE: To compare the posterior cruciate ligament(PCL) index with six different measurement methods, and analyze and verify its clinical diagnostic value in anterior cruciate ligament (ACL) injury. METHODS: The Magnetic resonance imaging (MRI) data of 225 knee joints in our hospital from May 2018 to March 2022 were retrospectively analyzed, aged from 18 to 60 years old, with a median of 32 years old. On the sagittal MRI images of 114 patients with ACL injury and 111 patients with intact ACL, Measure the straight-line distance (A) between the femoral attachment point and the tibial attachment point of the PCL on the MRI sagittal image and the maximum vertical distance (B) between the straight line and the arcuate mark point of the PCL on the sagittal image, calculate the PCL index and evaluate the diagnostic value of the PCL index for ACL injury. RESULTS: The PCL index of the ACL normal group and the ACL injury group were statistically described. There was no significant difference in PCL index 1, 2, 3 and 6 between the two groups(P>0.05). The difference of PCL index 4 and 5 between the two groups was statistically significant (P<0.001). This study only found that the PCL index 2, 6 in the ACL normal group had a negative correlation with the patient's age (correlation coefficient=-0.213, -0.819;P<0.05), and the PCL index 5 in the ACL injury group was significantly correlated with the patient's body mass index(BMI)had a negative correlation (correlation coefficient=-0.277, P<0.05). CONCLUSION The change of PCL index is helpful for the diagnosis of ACL injury, PCL index 4 and 5 can be used as effective reference indexes for diagnosing ACL injury in clinic.
Humans ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Posterior Cruciate Ligament/diagnostic imaging* ; Anterior Cruciate Ligament Injuries/diagnostic imaging* ; Anterior Cruciate Ligament ; Retrospective Studies ; Knee Joint ; Magnetic Resonance Imaging/methods*

The anterior cruciate ligament (ACL) is an important stabiliser of the knee and is commonly torn in sports injuries. Common indications for imaging after ACL reconstruction include persistent symptoms, limitation of motion and re-injury. Important postoperative complications include graft failure, impingement, arthrofibrosis and graft degeneration. This article aimed to familiarise the radiologist with magnetic resonance (MR) imaging appearances of properly positioned intact ACL grafts and to provide a comprehensive review of MR imaging features of complications following ACL reconstruction.
Anterior Cruciate Ligament ; diagnostic imaging ; surgery ; Anterior Cruciate Ligament Reconstruction ; adverse effects ; methods ; Humans ; Knee Joint ; diagnostic imaging ; surgery ; Magnetic Resonance Imaging ; Postoperative Complications ; diagnostic imaging ; Transplants ; diagnostic imaging ; Wound Healing

BACKGROUNDThere are different materials used for anterior cruciate ligament (ACL) reconstruction. It has been reported that both autologous grafts and allografts used in ACL reconstruction can cause bone tunnel enlargement. This study aimed to observe the characteristics of bone tunnel changes and possible causative factors following ACL reconstruction using Ligament Advanced Reinforcement System (LARS) artificial ligament.

METHODSForty-three patients underwent ACL reconstruction using LARS artificial ligament and were followed up for 3 years. X-ray and CT examinations were performed at 1, 3, 6, 12, 24, and 36 months after surgery, to measure the width of tibial and femoral tunnels. Knee function was evaluated according to the Lysholm scoring system. The anterior and posterior stability of the knee was measured using the KT-1000 arthrometer.

RESULTSAccording to the Peyrache grading method, grade 1 femoral bone tunnel enlargement was observed in three cases six months after surgery. No grade 2 or grade 3 bone tunnel enlargement was found. The bone tunnel enlargement in the three cases was close to the articular surface with an average tunnel enlargement of (2.5 ± 0.3) mm. Forty cases were evaluated as grade 0. The average tibial and femoral tunnel enlargements at the last follow-up were (0.8 ± 0.3) and (1.1 ± 0.3) mm, respectively. There was no statistically significant difference in bone tunnel width changes at different time points (P > 0.05). X-ray and CT measurements were consistent.

CONCLUSIONSThere was no marked bone tunnel enlargement immediately following ACL reconstruction using LARS artificial ligament. Such enlargement may, however, result from varying grafting factors involving the LARS artificial ligament or from different fixation methods.

Adult ; Anterior Cruciate Ligament ; diagnostic imaging ; surgery ; Anterior Cruciate Ligament Reconstruction ; methods ; Female ; Humans ; Male ; Middle Aged ; Radiography ; Reconstructive Surgical Procedures ; methods ; Transplantation, Autologous ; Transplantation, Homologous ; Young Adult

OBJECTIVE: To explore correlation between femoral mechanical axis and Blumensaat line (FMBL) angle of knee joint (angle between Blumensaat line and femoral mechanical axis), α angle (angle between Blumensaat line and axis of distal femur in sagittal plane) on EOS biplane imaging and non-contact anterior cruciate ligament(ACL) injury, and evaluate angle for its accuracy in predicting the populations prone to non-contact ACL injury. METHODS: From February 2018 to October 2020, EOS imaging and clinical data from 88 patients (176 knees) with unilateral non-contact ACL injury were retrospectively analyzed, including 53 males and 35 females, aged from 18 to 45 years old with an average of (30.3±6.2) years old, 48 patients on the left side and 40 patients on the right side. The patients were divided into ACL-affected group and ACL-health group according to side of ACL injuries, and 51 patients (51 knees) with non-ACL identified from EOS database were included in normal control group, including 28 males and 23 females, aged from 20 to 44 years old with an average of (31.6±5.5) years old, 26 patients on the left side and 25 patients on the right side. Full-length EOS imaging of skeleton extremitatis inferioris among three groups were reconstructed to 3D images of skeletal system with EOS software, and then FMBL angle and α angle were measured on the images. Univariate binary Logistic regression analysis was performed to determine the influence of the univariate(FMBL angle or α angle) on ACL status(normal or torn). And the angle cutoff value for univariate was selected based on receiver operating characteristics curve (ROC) to got the best accuracy. RESULTS: There was no statistically significant difference in age, gender and side distribution between ACL-injured group and normal control group(P>0.05). Statistical analyses (one-way ANOVA) indicated no significant difference in FMBL angle between ACL-injured knee group (32.8±2.3)° and ACL-injured contralateral knee group(32.5±2.3)°(P>0.05), but the values between two groups were significantly lower than that in normal control group (37.0±2.0)°(P<0.001). There was no statistically significant difference in α angle among three groups (P>0.05). Univariate binary Logistic regression analysis demonstrated that FMBL angle was risk factor for non-contact ACL injury[OR=0.433, 95%CI(0.330, 0.569), P<0.001]. The area under ROC curve for FMBL angle was 0.909[95%CI(0.861, 0.958), P<0.001], and the sensitivity and specificity were 70.5% and 98.0% respectively, cut-off value was 33.7°. CONCLUSION FMBL angle formed by Blumensaat line and femoral mechanical axis is one of the risk factors for non-contact ACL injury and has good predictive accuracy. The general population with FMBL angle below 33.7° may be increased risk for ACL injury.
Male ; Female ; Humans ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Anterior Cruciate Ligament Injuries/diagnostic imaging* ; Retrospective Studies ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging/methods* ; Anterior Cruciate Ligament/diagnostic imaging* ; Knee Joint/diagnostic imaging*

OBJECTIVETo explore the diagnostic value of the dual-energy technique with dual-source computed tomography (DSCT) for anterior cruciate ligament injuries.

METHODSThe clinical data of 8 patients with arthroscopic results were retrospectively reviewed. All patients underwent two- and three-dimensional imaging by multiplanar reconstruction, volume rendering, and tendon mode on DSCT. Dual-energy characteristics were compared with arthroscopic results.

RESULTSSix patients who were arthroscopically diagnosed as anterior cruciate ligament injuries, all of them were also correctly diagnosed by DSCT. Two patients who were arthroscopically diagnosed as normal, one was also diagnosed as normal by DSCT and the other was misdiagnosed. The overall agreement rate was 87.5% (7/8) . Under the dual energy tendon mode, the dual energy staining of the injured anterior cruciate ligament was lower than that of the contralateral normal cruciate ligament of the patient.

CONCLUSIONThe staining diminution in DSCT imaging may be a new feature that can be used to effectively diagnose anterior cruciate ligament injury.

Adolescent ; Adult ; Anterior Cruciate Ligament Injuries ; Female ; Humans ; Knee Injuries ; diagnostic imaging ; Male ; Tomography, X-Ray Computed ; methods ; Young Adult

OBJECTIVETo evaluate the values of spiral CT arthrography with multiplanar reconstruction and virtual arthroscopy technique in diagnosis of internal derangements of the knee.

METHODSTen bovine knees were used for experiment. The menisci, anterior and posterior cruciate ligaments and cartilage of these 10 bovine knees were injured with a hook. Each of the joints was injected with 100 ml air, then soon scanned with a PQ6000 spiral computed tomography scanner. The data obtained was input into the work station, and multiplanar reconstruction technique was used to illustrate lesions in the knees. The results of CT diagnosis were compared to those found by gross inspection of the specimens. Clinically, 10 knees of 9 patients diagnosed as internal derangement were evaluated with the same method after 50-70 ml air was injected into each of the joints. Nine months later, the data of 2 patients were used for CT endoscopy reconstruction. The results were compared with intraoperative findings.

RESULTSExperimentally, the sensitivity and specificity were 88.9% and 93.9% by detection of meniscal abnormalities, 85.7% and 100% by detection of cruciate ligament lesions, and 72.7% and 100% by detection of cartilage damage, respectively. Clinically, the sensitivity and specificity were 90.0% and 95.0% by detection of meniscal lesion. As to ligament, the figures were 85.7% and 100% respectively. Images of virtual arthroscopy simulated the images of real arthroscopy.

CONCLUSIONSSpiral CT arthrography of multiplanar reconstruction technique offers fine images of internal structures of the knee, with clear border and internal structure. It is an accurate method for detecting meniscal, cruciate and collateral ligament and cartilaginous lesions that cause internal derangement of the knee. Virtual arthroscopy technique is a hopeful method for detecting reasons of derangement of the knee.

Animals ; Anterior Cruciate Ligament ; pathology ; Anterior Cruciate Ligament Injuries ; Arthroscopy ; Cattle ; Female ; Humans ; Knee Injuries ; diagnostic imaging ; pathology ; surgery ; Male ; Medial Collateral Ligament, Knee ; injuries ; pathology ; Menisci, Tibial ; pathology ; Reconstructive Surgical Procedures ; Tibial Meniscus Injuries ; Tomography, Spiral Computed