Association between measures of trochlear morphology and structural features of patellofemoral joint osteoarthritis on MRI: The MOST study

The sulcus angle has been widely used in the literature as a measure of trochlear morphology. Recently, lateral trochlear inclination and trochlear angle have been reported as alternatives. The purpose of this study was to determine the association between measures of trochlear morphology and patellofemoral joint (PFJ) cartilage damage and bone marrow lesions (BMLs). Nine hundred seven knees were selected from the Multicenter Osteoarthritis Study, a cohort study of persons aged 50–79 years with or at risk for knee OA. Trochlear morphology was measured using lateral trochlear inclination, trochlear angle, and sulcus angle on axial MRI images; cartilage damage and BMLs were graded on MRI. We determined the association between quartiles of each trochlear morphology variable with the presence or absence of cartilage damage and BMLs in the PFJ using logistic regression. The strongest associations were seen with lateral trochlear inclination and lateral PFJ cartilage damage and BMLs, with knees in the lowest quartile (flattened lateral trochlea) having more than two times the odds of lateral cartilage damage and BMLs compared to those in the highest quartile (p < 0.0001). Lateral trochlear inclination may be the best method for assessment of trochlear morphology as it was strongly association with structural damage in the PFJ. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:1–8, 2012     

Predicting three‐dimensional patellofemoral kinematics from static imaging‐based alignment measures

Patellofemoral pain syndrome causes significant discomfort and disability among much of the general population. Despite recent breakthroughs in dynamic three‐dimensional imaging technologies to assess pathological patellofemoral motion, such tools remain costly for clinical diagnostics applications. Thus, this study investigated whether three‐dimensional patellofemoral kinematics could be predicted from routine two‐dimensional static measures of patellofemoral joint alignment quantified from magnetic resonance imaging (MRI) data acquired in full knee extension. Twenty‐six volunteers clinically diagnosed with patellofemoral pain (19 F/7 M, 25.9 ± 11.1 years) and 26 control subjects (19 F/7 M, 25.3 ± 7.7 years) were included in this IRB‐approved study. Static three‐dimensional sagittal T1‐weighted gradient recall echo and dynamic MRI scans were acquired. For the dynamic image acquisition, subjects cyclically flexed and extended their knee (at 30 cycles/min) while a full cine‐phase contrast MRI set (24 time frames of anatomic images and x‐, y‐, and z‐velocity images) was acquired. From these data, static measures of patellofemoral alignment and three‐dimensional patellofemoral kinematics were derived. Single and multiple regressions between static and kinematic variables were evaluated. Although shown reliable, the static MRI measures could only partially predict patellofemoral kinematics, with r²‐values ranging from 16% to 77%. This makes it imperitave that the current precise, accurate, 3D, dynamic imaging techniques be translated into clinical tools. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 441–447, 2013     

髌股关节发育不良对髌骨脱位磁共振成像表现的影响

背景：当存在髌股关节发育不良时,髌骨脱位的损伤程度较轻,因此更加依赖影像学诊断。 目的：比较髌股关节发育不良患者和髌股关节发育正常患者髌骨脱位时磁共振成像（MRI）表现的异同。 方法：回顾性分析54例经临床证实的髌骨脱位患者的MRI影像学资料。髌股关节发育不良患者32例,髌股关节发育正常患者22例。记录患者MRI中髌骨内侧骨挫伤或撕脱骨折、髌骨关节面骨软骨骨折、股骨外侧髁外侧部骨挫伤、髌股内侧支持带撕裂等情况。 结果：髌股关节发育不良组的32例患者中,髌骨内缘骨折12例,内侧支持带损伤10例,髌骨软骨损伤7例,股骨外髁骨挫伤18例;髌股关节发育正常组的22例患者中,髌骨内缘骨折8例,内侧支持带损伤14例,髌骨软骨损伤14例,股骨外髁骨挫伤14例。两组在内侧支持带损伤和髌骨内缘骨折上有显著统计学差异（P＜0.05）。 结论：MRI可以较好地诊断髌骨脱位。当髌股关节发育不良时,内侧支持带损伤和髌骨内缘骨折的发生率降低。     

急性滑脱性髌股关节撞击症的认识与MRI诊断

目的 认识并定义急性滑脱性髌股关节撞击症，探讨其发病机制及MRI诊断。方法 回顾性分析自2001年5月～2002年7月，34例经MRI诊断的急性滑脱性髌股关节撞击症的MRI表现，并结合临床资料、X线片、CT及关节镜所见进行分析。从矢状、冠状及横断三个平面行MR扫描，扫描方法采用：(1)三维快速梯度回波序列(FE3D)T1及T2加权像．该序列可较好地显示关节软骨及软骨下骨的损伤程度；(2）脂肪抑制梯度回波反转恢复序列(STIR)PD加权像，该序列对骨及软骨损伤有非常高的敏感性；(3)脂肪抑制快速自旋回波反转恢复序列(TSHIRT)T2加权像，该序列可显示韧带损伤情况。结果34例外伤后膝关节MRI均显示髌骨内下部及股骨外髁前外侧部对应的软骨下骨质异常信号改变。表明为骨损伤．与关节镜相比，34例中MRI可见20例髌骨内下部软骨骨折．其中15例为骨软骨骨折；8例股骨外髁前外侧部软骨骨折，其中6例为骨软骨骨折；11例关节囊内可见游离软骨或骨软骨碎片影。27例MRI显示不同程度髌内侧支持带损伤，其中Ⅰ度8例，Ⅱ度12例，Ⅲ度7例。所有患者均可见关节积液，其中单纯积液6例，血性积液18例．脂肪血性积液10例。23例可见髌骨外侧半脱位，结论 急性滑脱性髌股关节撞击症拟定义为当膝盖节急性屈曲外翻时．髌骨在向外侧滑脱或脱位后再自行复位的过程中．髌骨内侧面与股骨外髁相互撞击或挤压．并随之产生的一系列膝关节各解剖结构的损伤，主要包括髌骨内侧面骨软骨损伤、股骨外髁前外侧部骨软骨损伤、髌骨脱位或半脱位、髌内侧支持带损伤，关节囊积液。MRI提高对该症的检出率，并可全面而准确地表现各解剖结构的损伤程度。     

Identifying alignment parameters affecting implanted patellofemoral mechanics

Complications of the patellofemoral (PF) joint remain a common cause for revision of total knee replacements. PF complications, such as patellar maltracking, subluxation, and implant failure, have been linked to femoral and patellar component alignment. In this study, a dynamic finite element model of an implanted PF joint was applied in conjunction with a probabilistic simulation to establish relationships between alignment parameters and PF kinematics, contact mechanics, and internal stresses. Both traditional sensitivity analysis and a coupled probabilistic and principal component analysis approach were applied to characterize relationships between implant alignment and resulting joint mechanics. Critical alignment parameters, and combinations of parameters, affecting PF mechanics were identified for three patellar designs (dome, modified dome, and anatomic). Femoral internal–external (I‐E) alignment was identified as a critical alignment factor for all component designs, influencing medial–lateral contact force and anterior–posterior translation. The anatomic design was sensitive to patellar flexion–extension (F‐E) alignment, while the dome, as expected, was less influenced by rotational alignment, and more by translational position. The modified dome was sensitive to a combination of superior–inferior, F‐E, and I‐E alignments. Understanding the relationships and design‐specific dependencies between alignment parameters can aid preoperative planning, and help focus instrumentation design on those alignment parameters of primary concern. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1167–1175, 2012     

Prebiopsy magnetic resonance spectroscopy and imaging in the diagnosis of prostate cancer

Introduction: Existing screening investigations for the diagnosis of early prostate cancer lack specificity, resulting in a high negative biopsy rate. There is increasing interest in the use of various magnetic resonance methods for improving the yield of transrectal ultrasound‐guided biopsies of the prostate in men suspected to have prostate cancer. We review the existing status of such investigations. Methods: A literature search was carried out using the Pubmed database to identify articles related to magnetic resonance methods for diagnosing prostate cancer. References from these articles were also extracted and reviewed. Results: Recent studies have focused on prebiopsy magnetic resonance investigations using conventional magnetic resonance imaging, dynamic contrast enhanced magnetic resonance imaging, diffusion weighted magnetic resonance imaging, magnetization transfer imaging and magnetic resonance spectroscopy of the prostate. This marks a shift from the earlier strategy of carrying out postbiopsy magnetic resonance investigations. Prebiopsy magnetic resonance investigations has been useful in identifying patients who are more likely to have a biopsy positive for malignancy. Conclusions: Prebiopsy magnetic resonance investigations has a potential role in increasing specificity of screening for early prostate cancer. It has a role in the targeting of biopsy sites, avoiding unnecessary biopsies and predicting the outcome of biopsies.     

A new classification of injury patterns of the medial patellofemoral ligament after acute lateral patella dislocation detected using magnetic resonance imaging studies

Introduction

Acute lateral patellar dislocation is a very common condition in orthopedics, especially among adolescents and physically active patients. To evaluate distinct medial patellofemoral ligament (MPFL) injury patterns and the associated knee pathology after acute lateral patellar dislocation (ALPD) using magnetic resonance imaging (MRI) studies, which is essential for the development of treatment protocols.

Clinical value of magnetic resonance imaging of the knee

Background : Magnetic resonance (MR) imaging is an accurate imaging modality of the knee. The role of MR in clinical practice has not been precisely defined, largely due to the relative expense of the technique. Methods : For each new patient with a knee problem who was referred for MR, a provisional diagnosis was made together with a level of certainty regarding the diagnosis. The waiting time for the scan was recorded. To assess clinical usefulness the MR diagnosis was compared with the provisional diagnosis and classified according to the following descending order of value: unexpected negative (no intra‐articular pathology), confirmatory negative, unexpected positive or confirmatory positive. To assess accuracy of the MR diagnosis, the operative diagnosis was compared to the MR diagnosis in those patients who underwent arthroscopy. Results : Fifty‐two per cent of scans were assessed as being very useful and a further 20% were assessed as being moderately useful. Magnetic resonance had a 95% accuracy for medial meniscal tears, 91% accuracy for lateral meniscal tears, and 98% accuracy for anterior cruciate ligament tears, similar to previously reported studies. The diagnostic arthroscopy rate in the patients who underwent MR scanning was similar to that in patients for whom the surgeon was more confident about the diagnosis and who therefore did not undergo MR scanning. The diagnostic arthroscopy rate could have been reduced if surgery had not been performed in 14 patients who had a negative MR scan. Conclusions : There is a role for selective use of MR in the assessment of knee conditions. In particular, MR can be used to reduce the diagnostic arthroscopy rate.     

磁共振成像对隆乳材料鉴别及并发症处理的指导意义

目的:分析隆乳材料及术后并发症的MRI表现特点,评估磁共振检查的临床价值。材料和方法:搜集53例经过MRI检查的隆乳术后患者,针对不同的隆乳材料制定合适的扫描序列,分析植入或注射不同类型假体的MRI表现。结果:四种隆胸材料(聚丙烯酰胺水凝胶、硅凝胶、自体脂肪移植、透明质酸)的位置、信号、边界在磁共振图像上有特征性表现,通过扫描序列组合及增强扫描可以准确判断隆胸材料的性质及并发症情况,动态增强扫描还可以发现腺体病变。结论:MRI是鉴别乳腺假体类型及指导术后并发症处理的较好方法。     

Correlation between clinical features and magnetic resonance imaging findings in lumbar disc prolapse

Background:

Lumbar disc prolapse is one of the common causes of low back pain seen in the working population. There are contradictorty reports regarding the clinical significance of various magnetic resonance imaging (MRI) findings observed in these patients. The study was conducted to correlate the abnormalities observed on MRI and clinical features of lumbar disc prolapse.

Materials and Methods:

119 clinically diagnosed patients with lumbar disc prolapse were included in the study. Clinical evaluation included pain distribution, neurological symptoms and signs. MR evaluation included grades of disc degeneration, type of herniation, neural foramen compromise, nerve root compression, and miscellaneous findings. These MRI findings were tested for inter- and intraobserver variability. The MRI findings were then correlated with clinical symptoms and the level of disc prolapse as well as neurological signs and symptoms. Statistical analysis included the Kappa coefficient, Odd’s ratio, and logistic regression analysis.

Results:

There were no significant inter- or intraobserver variations for most of MRI findings (Kappa value more than 0.5) except for type of disc herniation which showed a interobserver variation of 0.46 (Kappa value). The clinical level of pain distribution correlated well with the MRI level (Kappa 0.8), but not all disc bulges produced symptoms. Central bulges and disc protrusions with thecal sac compression were mostly asymptomatic, while centrolateral protrusions and extrusions with neural foramen compromise correlated well with the dermatomal distribution of pain. Root compression observed in MRI did not produce neurological symptoms or deficits in all patients but when deficits were present, they correlated well with the presence of root compression in MRI. Multiple level disc herniations with foramen compromise were strongly associated with the presence of neurological signs.

Conclusions:

The presence of centrolateral protrusion or extrusion with gross foramen compromise correlates with clinical signs and symptoms very well, while central bulges and disc protrusions correlate poorly with clinical signs and symptoms. The presence of neural foramen compromise is more important in determining the clinical signs and symptoms while type of disc herniation (bulge, protrusion, or extrusion) correlates poorly with clinical signs and symptoms.     

Correlation between neurological recovery and magnetic resonance imaging in Pott's paraplegia

Background:

Spinal cord/nerve root compression secondary to a tubercular epidural abscess leads to neurological deficit. Depending on the extent and duration of compression, the end result after treatment may vary from complete recovery to permanent deficit. ASIA has been used extensively to correlate between MRI and neurological status due to traumatic spine injuries. MRI has stood as an invaluable diagnostic tool out of the entire range of current imaging modalities. However, inspite of considerable literature on the applications of MRI in spinal tuberculosis, there have been few studies to assess the relationship between the MRI findings and the neurological deficit as assessed by clinical examination.

Aims:

The objective of this study was to ascertain whether the findings of magnetic resonance imaging (MRI) correlate well with the actual neurological recovery status using the American Spinal Injury Association impairment scale (ASIA) in patients with spinal compression secondary to tuberculous spondylitis.

Materials and Methods:

60 patients (mean age 43.6 years) diagnosed as spinal tuberculosis by MRI/cytology/histopathology were examined and classified into ASIA impairment scale A-E based on the ASIA and again reclassified after 6 months of therapy to assess functional recovery. Similarly, they underwent MR imaging at the start and at the completion of 6 months of therapy to assess the structural recovery. The MRI features of recovery were correlated with the actual neurological recovery as ascertained by the ASIA.

Results:

Before starting treatment 1 patient (2.08%) was in ASIA A, 2 (4.16%) were in ASIA B, 9 (18.75%) were in ASIA C, 36 (75%) were in ASIA D and 12 (20%) were in ASIA E. There was a significant difference in the epidural abscess thickness, thecal compression and cord compression between ambulatory (ASIA D and ASIA E) and non ambulatory patients (ASIA A, ASIA B and ASIA C). After 6 months of therapy 30 (90%) patients in ASIA D and 5 (55.5%) in ASIA C had complete neurological recovery. Both patients from ASIA B improved to ASIA D. Single patient who was in ASIA A before treatment remained non ambulatory (ASIA C) after treatment. Overall 33 (78.5%) patients showed complete recovery at final followup. Out of all the MRI features, only size of epidural abscess was found to be a poor prognostic factor for recovery of neurological deficit.

Conclusions:

There are several parameters on MRI which correlate with the severity of neurological impairment according to ASIA score and resolution of those features on treatment is also correlated well with neurological recovery.     

Intrasacral meningeal cyst demonstrated by magnetic resonance imaging

Intrasacral meningeal cyst, first reported by Enderle [8] in 1932, is a rare cause of low-back and leg pain [2, 3, 4, 5, 12]. Non-invasive magnetic resonance imaging appears to be very useful for initial identification of intrasacral cystic masses.     

Use of i-gel in magnetic resonance imaging

Anesthesia for magnetic resonance imaging (MRI) requires special equipment that can be used in the presence of a magnetic field. Endotracheal tube and various laryngeal mask airway devices have a variable quantity of ferromagnetic material in the pilot balloon that could reduce image quality and result in artifacts. The i-gel is a reliable, easily inserted airway device, and causes minimal interference in image quality. We used i-gel in 10 anaesthetized adult patients undergoing MRI. The quality of image, evidence of airway, tongue, and dental trauma were assessed throughout the procedure. All scans were diagnostically adequate. Therefore, we concluded that i-gel causes the least ferromagnetic interference compared with other devices and improves the quality of imaging and produces minimal artifact while scanning.     

中老年人胫骨结节-股骨滑车沟距离与髌股关节软骨退变之间的关系研究

目的：利用膝关节核磁共振成像（MRI）扫描探讨中老年人髌股关节软骨退变程度与胫骨结节-股骨滑车沟间距（TT-TG）之间的关系。方法：选取2020年9月—2022年12月在我院行膝关节MRI扫描的中老年患者515例。由两名从事骨科相关的影像科医生对髌股关节软骨退变分级进行客观评价。并利用GE工作站使用膝关节轴位图像后处理,进行TT-TG距离测量。比较髌骨侧软骨退变及股骨滑车侧软骨退变各组间TT-TG间距,采用Logistic回归分析TT-TG间距是否是关节软骨退变的影响因素,并绘制受试者特征曲线（ROC）进行分析。结果：髌骨侧软骨退变及股骨滑车侧软骨退变各组间TT-TG间距存在统计学意义（P <0.05）。髌骨侧关节软骨退变分级与TT-TG间距存在相关性（P=0.021）;股骨滑车侧关节软骨退变分级与TT-TG间距不存在相关性（P=0.737）。TT-TG间距对评估髌骨侧关节软骨退变存在诊断意义（AUC=0.583）,但诊断能力较低;而对股骨滑车侧关节软骨退变则不存在诊断意义（AUC=0.487）。结论：TT-TG间距对于髌骨侧关节软骨退变分级有一定的预测作用,但是无法准确预测股骨...     

The association of magnetic resonance imaging (MRI)-detected structural pathology of the knee with crepitus in a population-based cohort with knee pain: the MoDEKO study

Osteoarthritis (OA) is the most common arthropathy of the knee joint¹. Symptoms reported by patients and signs noted during physical examination guide clinicians in identifying subjects with knee OA ^{[2] , [3] and [4]} .Pain is one of the most important symptoms reported by subjects with knee OA ^{[2] and [3]} . Although very common, pain is a non-specific symptom, related to pathology in several structures within the knee joint, and includes synovitis⁵, subchondral bone marrow lesions⁶, and joint effusion⁷. Further, pain is a subjective symptom that cannot be directly measured or assessed during physical examination.Crepitus or crepitation in association with arthritis is defined as a crackling or grinding sound on joint movement with a sensation in the joint. Crepitus may occur with or without pain and is a common finding during physical examination in subjects with knee OA ^{[2] , [3] , [4] , [8] and [9]} .It is not known whether crepitus is related to pathology in various structures within the knee. The aim of our study was to determine the cross-sectional associations of structural pathologies within the knee with crepitus in a population-based cohort with knee pain, using magnetic resonance imaging (MRI).Subjects with knee pain were recruited as a random population sample, with crepitus assessed in each compartment of the knee using a validated and standardized approach during physical examination¹⁰. MRI of the knee was performed to assess cartilage morphology, meniscal morphology, osteophytes, cruciate ligaments, and collateral ligaments. For both compartment-specific and whole-knee analyses, a multiple logistic regression analysis was performed to assess the associations of MRI-detected structural pathology with crepitus, adjusting for potential confounders. Variables were selected by backwards elimination within each compartment and in the overall knee models, and only statistically significant variables remained in the “selected” models; remaining variables in these models are adjusted for each other. An increased risk for compartment-specific crepitus was associated with osteophytes at the patellofemoral (PF) and lateral tibiofemoral (LTF) joints. Crepitus was associated with osteophytes and medial collateral ligament (MCL) pathology at the medial tibiofemoral (MTF) compartment, but cartilage damage was negatively associated with crepitus at this compartment. In the selected whole-knee model, only meniscal tears were associated with an increased risk for general crepitus. Thus, it seems that crepitus may be associated with pathology in several internal structures.