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*

OBJECTIVE: To explore correlation between imaging classification of knee osteoarthritis (KOA) and axis angle of tibiofemoral and patellofemoral joints. METHODS: A retrospective analysis of 739 middle-aged and elderly patients with KOA (1 026 knee joints) who underwent vertical X-ray examination of both lower limbs and lateral knee joints from September 2018 to December 2020. Among them, 63 patients with K-L 0 grade (95 knee joints), 100 patients with K-L 1 grade (130 knee joints), 161 patients with K-L 2 grade (226 knee joints), 187 patients with K-L 3 grade (256 knee joints), and 228 patients of K-L 4 grade (319 knee joints). According to relative position of knee joint center and line between hip joint center and ankle joint center, the affected knee was divided into varus group(844 knees joints) and valgus group (182 knees joints). According to Install-Salvati method, the affected knee was divided into three groups, such as high patella (patella height>1.2 mm, 347 knees joints), median patella (patella height ranged from 0.8 to 1.2 mm, 561 knees joints), and low patella (patella height<0.8 mm, 118 knees joints). Lower femur angle, upper tibia angle, femoral neck shaft angle, femoral tibial angle, joint gap angle, hip-knee-ankle angle, patella-femoral angle and patella height among different groups were observed and compared. RESULTS: (1) In varus KOA group, there were statistical differnces in hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades (P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle and K-L grade were significantly positively correlated at 0.01(P<0.05);femoral neck shaft angle and K-L grade showed negative correlation at 0.01(P<0.05). (2) In valgus KOA group, hip-knee-ankle angle, there were statistical differences in tibiofemoral angle, inferior femoral angle, superior tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades(P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, and femoral neck shaft angle showed negative correlation with K-L grades at level of 0.01 (P<0.05);joint gap angle and K-L grades showed significantly positive correlation at level of 0.01(P<0.05). (3) In high patella group, there were statistically differences in patellar height and patellar femoral angle of different K-L grades(P<0.05);there were no statistical difference in patella height and patellar femoral angle of different K-L grades in median patella group. There was no significant difference in patella heightin low patella group with different K-L grades(P>0.05), and there was statistical difference in patellofemoral angle(P<0.05). Patellar height and patella-femoral angle of high patella group were significantly positively correlated with K-L grades at the level of 0.01 (P<0.05);patella height and patella-femoral angle were not correlated with K-L grades in median patella group(P>0.05). There was no correlation between height of patella and K-L grade in low patella group (P>0.05). There was significant negative correlation between patella-femoral angle and K-L grade at level of 0.05 (P<0.05). CONCLUSION Inferior femoral angle, tibiofemoral angle, joint gap angle, hip-knee-ankle angle, femoral neck shaft angle and high patella are related to K-L classification of varus KOA, which could be used for early diagnosis and provide objective data for efficacy analysis of conservative treatment.
Aged ; Middle Aged ; Humans ; Patellofemoral Joint/diagnostic imaging* ; Osteoarthritis, Knee/diagnostic imaging* ; Retrospective Studies ; Knee Joint ; Femur/diagnostic imaging* ; Tibia

OBJECTIVE: To investigate the relationship between bone marrow edema and pathological changes, symptoms and signs of severe knee osteoarthritis. METHODS: From January 2020 to March 2021, 160 patients with severe knee osteoarthritis who underwrent MRI of the knee at the Department of Bone and Joint, Wangjing Hospital, China Academy of Chinese Medical Sciences were included. Eighty patients with bone marrow edema were selected as the case group, including 12 males and 68 females, aged from 51 to 80 years old with an average of (66.58±8.10) years old, the duration of disease 5 to 40 months with an average of (15.61±9.25) months. Eighty patients without bone marrow edema were selected as the control group, including 15 males and 65 females, aged from 50 to 80 years old with an average of (67.82±8.05) years old, the duration of disease 6 to 37 months with an average of (15.75±8.18) months, BMI was (28.26±3.13) kg·m^-2 ranged from 21.39 to 34.46 kg·m^-2. The degree of bone marrow edema was evaluated by knee whole oragan magnetic resonance imaging score (WORMS). The degree of knee osteoarthritis was evaluated by Kellgren- Lawrence(K-L) grade and Western Ontario and McMaster University Osteoarthritis Index (WOMAC). The degree of joint pain was evaluated by visual analogue scale(VAS) and WOMAC pain score, the joint signs were evaluated by tenderness, percussion pain, joint swelling and joint range of motion. To explore the relationship between bone marrow edema and knee osteoarthritis, the prevalence of bone marrow edema and K-L grade were compared between the two groups. Furthermore the WORMS score and WOMAC index, pain-related score, and sign-related score correlation coefficient were analyzed to further explore the relationship between bone marrow edema and knee osteoarthritis index, joint pain symptoms and signs. RESULTS: There was 68.75% (55/80) of the patients in the case group were in K-L grade Ⅳ, and 52.5% (42/80) in the control group, indicating a higher proportion of patients with grade Ⅳ in the case group than the control group (χ²=4.425, P<0.05). In the case group, there was a strong correlation between bone marrow edema WORMS score and knee osteoarthritis WOMAC index. (r=0.873>0.8, P<0.001), a moderate correlation between WORMS score and VAS score and WOMAC pain score(r=0.752, 0.650>0.5, P<0.001), a moderate correlation between WORMS score and percussion pain score (r=0.784>0.5, P<0.001), and a weak correlation between WORMS score and VAS and tenderness score, joint swelling score and joint range of motion score (r=0.194, 0.259, 0.296<0.3, P<0.001). CONCLUSION Our study suggests that severe knee osteoarthritis is associated with an increased risk of bone marrow edema. Bone marrow edema can also lead to knee osteoarthritis joint pain, with percussion pain being a positive sign, but tenderness, joint swelling and limitation of activity are not significantly related to bone marrow edema.
Male ; Female ; Humans ; Osteoarthritis, Knee/pathology* ; Bone Marrow/pathology* ; Knee Joint/diagnostic imaging* ; Bone Marrow Diseases/etiology* ; Pain/pathology* ; Arthralgia ; Edema/pathology*

Bone development shows certain regularity with age. The regularity can be used to infer age and serve many fields such as justice, medicine, archaeology, etc. As a non-invasive evaluation method of the epiphyseal development stage, MRI is widely used in living age estimation. In recent years, the rapid development of machine learning has significantly improved the effectiveness and reliability of living age estimation, which is one of the main development directions of current research. This paper summarizes the analysis methods of age estimation by knee joint MRI, introduces the current research trends, and future application trend.
Epiphyses/diagnostic imaging* ; Age Determination by Skeleton/methods* ; Reproducibility of Results ; Magnetic Resonance Imaging/methods* ; Knee Joint/diagnostic imaging*

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*

OBJECTIVE: To explore 3.0T MRI accurate measurement of knee cartilage thickness in healthy youth provides reliable anatomical parameters for quantitative diagnosis of osteoarthritis and accurate osteotomy of joint replacement. METHODS: From January 2013 to December 2013, 30 healthy young volunteers including 14 males and 16 females with an average age of (25.8±2.4) years old ranging from 22 to 33 years were recruited in Changchun, Jilin Province, and a 3.0T MRI scan was performed on the bilateral knee joints of each volunteer. The cartilage thickness was measured on the lateral femoral condyle (LFC), medial femoral condyle (MFC), lateral tibial plateau (LTP) and medial tibial plateau (MTP). RESULTS: In four regions of the knee joint:LFC, MFC, LTP and MTP, whether young men or women, there was no significant difference in cartilage thickness between the left and right knee joints (P>0.05). There were significant differences in knee cartilage thickness between healthy young men and women (P<0.05). In the same sex group, LFC cartilage thickness was thinner in the middle, thicker in front and rear;MFC cartilage thickness was the thinnest in front and gradually thickening from the front to the rear; LTP cartilage thickness was thickest in the middle, second in the rear and thinnest in the front;MTP cartilage thickness was the thinnest in the front, was relatively uniform in the middle and rear and thicker than that in the front. CONCLUSION In Northeast China, among healthy adults aged 22 to 33, gender difference may be an important factor in the difference of cartilage thickness in various regions of the knee joint. Regardless of whether male or female healthy young people, the cartilage thickness of the entire knee joint is unevenly distributed, but there is no significant difference in cartilage thickness in the same area between the left and right knee joints.
Adult ; Adolescent ; Humans ; Male ; Female ; Young Adult ; Cartilage, Articular/diagnostic imaging* ; Knee Joint/surgery* ; Osteoarthritis ; Magnetic Resonance Imaging ; Femur

OBJECTIVE: To investigate the diagnostic value of multislice spiral CT (MSCT) and MRI in occult fracture of knee joint with meniscus and ligament injury. METHODS: From January 2020 to March 2021, 63 patients with knee occult fracture with meniscus and ligament injury, including 41 males and 22 females, aged from 21 to 67 years old, with an average of (44.35±8.77) years old, the course of disease ranged from 1 to 6 days, with an average of (4.64±1.75) days, the body mass index (BMI) was (19.85±2.78) kg/m². MSCT and MRI data of 63 patients were collected and statistically analyzed to evaluage their diagnist value. RESULTS: The detection of MRI for occult knee fravtures with meniscus and ligament injury, joint cavity effusion, bone marrow edema, and articular surface injury were 100.00% (63/63), 95.24% (60/63), 42.86% (27/63) and 36.51% (23/63), respectively. The detection rates of MSCT were 49.21% (31/63), 41.27% (26/63), 0.00% (0/63) and 1.59% (1/63), respectively, significantly lwver than that of MRI (P<0.05). The diagnostic sensitivity, specificity and accuracy of MRI were significantly higher than those of MSCT(P<0.05). CONCLUSION The sensitivity, specificity and accuracy of magnetic resonance imaging in the diagnosis of occult fracture of knee joint with meniscus and ligament injury are significantly better than that of MSCT. MRI has higher accuracy in the diagnosis of peripheral tissue diseases such as joint cavity, articular surface and bone marrow, and can reduce the risk of clinical misdiagnosis.
Male ; Female ; Humans ; Young Adult ; Adult ; Middle Aged ; Aged ; Tibial Meniscus Injuries/diagnostic imaging* ; Fractures, Closed/diagnostic imaging* ; Arthroscopy/methods* ; Knee Injuries/diagnostic imaging* ; Knee Joint/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Ligaments ; Meniscus ; Tomography, Spiral Computed ; Fractures, Bone ; Anterior Cruciate Ligament Injuries

Arthroplasty, Replacement, Knee ; Humans ; Knee Joint/surgery* ; Leg ; Lower Extremity/diagnostic imaging* ; Osteoarthritis, Knee/surgery* ; Rotation ; Tibia/surgery*

OBJECTIVE: Based on the anatomical differences between discoid lateral meniscus(DLM) and normal lateral meniscus (NLM), this study aims to setting up the ultrasound examination parameters to distinguish DLM and NLM and explore the diagnostic value of these parameters on DLM. METHODS: According to the inclusion, exclusion and matching criteria, 66 DLM patients(DLM group) and 132 NLM patients with other knee joint diseases(NLM group), hospitalized from October 2019 to June 2020, were included in this study. There were 18 males and 48 females in the DLM group, ranging in age from 3 to 60 years old, with a mean of (36.9±12.1) years old;36 males and 96 females in the NLM group, ranging in age from 3 to 60 years old, with a mean of (40.0±12.2) years old. Philips high frequency(3.0 to 12.0 MHz) linear array ultrasound probe was used to examine the lateral meniscus of all patients in two groups. Nine parameters including the thickness, width and the included angle of the anterior angle, body and posterior angle respectively in the lateral meniscus were measured. The included angke is formed by the chords of the upper and lower curved surfaces of the meniscus at the free edge. The independent t test was used to analyze the difference of the measured parameters between the DLM group and the NLM group. The receiver operating characteristic(ROC) curve was used to evaluate the cut-off value of each parameter for diagnosing DLM and the corresponding sensitivity, specificity, positive predictive value, negative predictive value, and area under the ROC curve(AUC). RESULTS: The above 9 ultrasound measurement parameters between the DLM group and the NLM group had significant statistical differences(P<0.001). The ROC curve analysis method evaluated the cut-off value and diagnostic capabilities of these nine ultrasound parameters for DLM. The results showed that the cut-off value of the included angle of anterior part, body and posterior part were 25.85°, 24.85° and 29.15 °, respectively;and the sensitivity, specificity, negative predictive value, positive predictive value and AUC were significantly higher than other parameters, which were 88%, 91%, 79%, 95%, 0.94;89%, 94%, 82%, 97%, 0.96; 92%, 97%, 86%, 98%, 0.97, respectively. CONCLUSION Ultrasound diagnosis of DLM is feasible and reliable. The diagnostic ability of the included angle of the anterior part, body and posterior part in the lateral meniscus measured by ultrasound to diagnose DLM are significantly better than other ultrasound measurement parameters, and the sensitivity and specificity of those parameters are close to MRI. Therefore, ultrasound can be used as a reliable method for preliminary diagnosis of DLM.
Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Humans ; Knee Joint/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Male ; Menisci, Tibial/diagnostic imaging* ; Middle Aged ; Osteoarthritis, Knee ; Ultrasonography ; Young Adult

OBJECTIVE: To explore the abnormal manifestations and clinical features of patients with gout according to the location of crystal deposits: in articulars or in tendons. METHODS: A total of 105 patients with gout who were continuously treated in the Department of Rheumatology and Immunology of Peking University People's Hospital from June 2019 to December 2019 were selected and their knees, ankles, toes and painful joints and tendons were examined by high-frequency ultrasound. Then we grouped them according to the presence or absence of sodium urate crystals and the location of the crystals, collected their clinical data, and analyzed the clinical characteristics. RESULTS: Among the 105 patients, 25 patients had no crystal deposits in the joints or tendons (as the non-crystal group), 43 patients had intra-articular crystals (as the joint group), and 37 patients had intra-tendon crystals with or without intra-articular crystals (as the tendon group). Among them, the most involved part of sodium urate crystals deposited in the joints was the metatarsophalangeal joint (29 cases, 67.4%), followed by knee joints (10 cases, 23.2%), ankle joints (9 cases, 20.9%). The most involved part of sodium urate crystals deposited in the tendon was the quadriceps tendon (16 cases, 43.2%), followed by the Achilles tendon (13 cases, 35.1%), the patellar tendon (12 cases, 32.4%), and the three heads of brachii tendons (5 cases, 13.5%). The three groups were compared using multi-sample analysis of variance/multi-sample rank sum test. Age, age of first increase in uric acid (UA), serum glucose (Glu) level and C reactive protein (CRP) were all significantly different. After multiple comparisons, compared with the non-crystal group, age, the age of first increase in uric acid, and CRP were significantly higher in the tendon group. There was no significant difference between the non-crystal group and the joint group. There was no significant difference between the tendon group and the joint group. CONCLUSION In patients with gout, it is common for ultrasound to find crystals deposited in joints or tendons. The most commonly affected parts include the metatarsophalangeal joint, knee joint, ankle joint, quadriceps tendon, Achilles tendon, patellar tendon, and triceps tendon. There were significant differences among the three groups in age, age of first increase in uric acid, CRP and blood glucose, and the proportion of urinary calculi in patients with crystal deposits was significantly higher than those without crystal deposits.
Achilles Tendon ; Gout ; Humans ; Knee Joint ; Metatarsophalangeal Joint/diagnostic imaging* ; Uric Acid