Clubfoot: Congenital Talipes Equinovarus.

Congenital talipes equinovarus (CTEV), also known as clubfoot, is a common musculoskeletal entity that affects one to two per 1000 live births worldwide. Imaging modalities including radiography, US, and MRI have emerged as valuable tools for the diagnosis, treatment, and monitoring of CTEV. The deformity is characterized by midfoot cavus, forefoot adductus, and hindfoot varus and equinus. The Ponseti method of manipulation and serial casting is the standard treatment of CTEV. Radiography shows the anatomy, position, and relationships of the different bones of the foot. US allows accurate assessment of cartilaginous and bony structures, in addition to its inherent advantages such as absence of ionizing radiation exposure. One of the indications for US is to monitor the response to Ponseti method treatment. MRI enables visualization of bones, cartilage, and soft tissues and allows multiplanar evaluation of deformities, providing a comprehensive imaging analysis of CTEV. An integrated approach that combines clinical examination and imaging findings is essential for effective management of CTEV. The authors provide a comprehensive overview of CTEV with a review of imaging modalities to help evaluate CTEV, focusing on radiography, US, and MRI. Using this article as a guide, radiologists involved in the assessment and treatment of CTEV can contribute to the management of the condition. ©RSNA, 2024 Supplemental material is available for this article.

Differential Diagnosis of Facet Joint Disorders.

Spinal pain due to facet joint disease is difficult to diagnose since the clinical history and physical examination findings are usually nonspecific. Facet joint disorders have a wide range of causes and, because of the potential for chronic back pain and disability, an accurate diagnosis is essential. The most frequent cause of pain in facet joints is osteoarthritis, which can be assessed at radiography, CT, or MRI. Ganglion and synovial cysts of the facet joints can cause compressive symptoms of adjacent structures, especially radiculopathy, lower back pain, and sensory or motor deficits. In ankylosing spondylitis, imaging findings of the facet joints are useful not only for diagnosis but also for monitoring structural changes. In septic arthritis of the facet joints, an early diagnosis at MRI is essential. Gout and metabolic diseases are best evaluated at dual-energy CT, which allows the depiction of crystals. Traumatic dislocations of facet joints are usually unstable injuries that require internal reduction, fixation, and fusion and can be well assessed at CT with three-dimensional reconstructions. Facet joint neoplasms like osteoid osteoma, plasmacytoma, tenosynovial giant cell tumor, and osteochondroma are best evaluated at CT or MRI. The authors provide an overview of key imaging features of the most common facet joint disorders along with anatomic tips and illustrative cases. Acknowledging key imaging findings for the differential diagnosis of facet joint disorders plays a crucial role in the diagnostic accuracy and proper treatment approach for such entities. Online supplemental material is available for this article. ©RSNA, 2021.

Giant axonal neuropathy with novel GAN pathogenic variant in a patient of consanguineous origin from Poonch Jammu and Kashmir-India.

Giant axonal neuropathy (GAN) is a severe and rare autosomal recessive neurodegenerative disorder of childhood affecting both the peripheral and central nervous systems (CNS). It is caused by mutations in the GAN (gigaxonin) gene linked to chromosome 16q24. Here, we present a 15-year-old male patient with GAN from a consanguineous family of Poonch, Jammu and Kashmir (J&K)-India. Whole-exome sequencing (WES) was employed to unravel the genetic cause of GAN in the proband. Pathogenic variant identified with WES was confirmed in other affected sibling using Sanger sequencing. Magnetic resonance imaging (MRI) and detailed clinical investigation was also carried out on proband. WES revealed a novel homozygous stopgain GAN mutation (NM_022041, c.C1028G, p.S343X) in the patient. MRI of brain displayed bilateral symmetrical confluent areas of deep white matter signal changes affecting periventricular regions (with sparing of subcortical U-fibers), posterior limbs of internal capsules, thalami, external capsules, and semioval centers. The patient was initially suspected to be a case of metachromatic leukodystrophy. However, WES analysis revealed a pathogenic variant in GAN gene as causative. No other pathogenic variant relevant to any other type of dystrophy was reported in WES. Our findings extend the geographical distribution of GAN to even a very remote region in India, extend the mutational and imaging spectrum of GAN and substantiate the need for introducing genetic testing and counselling in primary referral centers/district hospitals in India.

Evaluation of Posterior Cruciate Ligament and Intercondylar Notch in Subjects With Anterior Cruciate Ligament Tear: A Comparative Flexed-Knee 3D Magnetic Resonance Imaging Study.

PURPOSE: To determine if posterior cruciate ligament (PCL) and intercondylar notch (IN) morphometries and volumetrics act as risk factors for anterior cruciate ligament (ACL) tears. METHODS: A prospective case-controlled magnetic resonance imaging (MRI) study was conducted with subjects presenting noncontact knee injuries. Exclusion criteria were previous surgery, PCL tear, osteoarthritis, tumors, or infectious and inflammatory conditions. All participants underwent a flexed-knee 3-dimensional (3D) magnetic resonance imaging (MRI) to uniformly straighten PCL. MR images were independently reviewed by 2 radiologists and assessed for 2D and 3D measurements (bicondylar width; IN angle, depth, width, and cross-sectional area; PCL width, thickness, and cross-sectional area; and IN and PCL volumes). Clinical profiles were tabulated and subjects were divided into cases (ACL tear) and controls (without ACL tear). RESULTS: The study was composed of 50 cases versus 52 controls (N = 102), with a mean age of 36.8 years. There was no difference between groups (P > .05) regarding age, gender, body mass index, time from injury, Tegner score, flexion angle, limb side, intensity of injury, or familial or opposite limb history of tear. Agreement between readers ranged from substantial to almost perfect. Subjects with ACL tear presented with lower IN width, lower IN minus PCL widths, lower Notch Width Index, higher PCL/IN width proportion, higher PCL thickness, lower IN depth minus PCL thickness, and higher PCL thickness/IN depth proportion (P < .05). Moreover, higher PCL/IN cross-sectional area proportion, higher PCL volumes (OR = 9.01), and higher PCL/IN volume proportion were also found in cases. CONCLUSIONS: Our study shows that subjects with ACL tears present not only reduced IN but also larger PCL dimensions. These findings, isolated and combined, and especially PCL volume, might be suggestive as risk factors for ACL tears owing to the reduction of its space inside the IN. LEVEL OF EVIDENCE: Level III, comparative group.

Glenohumeral position during CT arthrography with arthroscopic correlation: optimization of diagnostic yield.

OBJECTIVE: To evaluate the diagnostic yield of two acquisitions of single-contrast CT arthrography (CTA) of the shoulder in internal, neutral, or external glenohumeral rotation with arthroscopic correlation. MATERIALS AND METHODS: The CT study was obtained using two acquisitions (first the humerus positioned in maximum tolerated external rotation with the arm along the body and the second with the humerus in internal rotation with the palm placed flat on the table). Two independent readers blinded to the arthroscopic results evaluated the CTA images for labral tears, glenoid bone loss/fractures, and cartilage loss. For each CTA acquisition, sensitivity and specificity for detection of the aforementioned pathology were assessed. Inter-reader agreement was quantified by weighted ĸ statistics. RESULTS: Sensitivity and specificity for detecting anteroinferior or posterior labral tears was highest with neutral rotation (sensitivity 91-100%, specificity 61-100%). For glenoid fracture, sensitivity (67%) was highest with external rotation and specificity (100%) was highest with internal rotation. For cartilage loss, sensitivity (64%) and specificity (89%) was highest with external rotation and neutral rotation, respectively. Neutral rotation showed high sensitivity and specificity for glenoid fractures and cartilage loss. Inter-reader agreement ranged from fair to very good. CONCLUSIONS: Neutral glenohumeral position in shoulder CT arthrography was adequately sensitive and specific for the detection of intra-articular pathology, avoiding the use of more than one acquisition.

Comparison of the diagnostic accuracy of 99 m-Tc-MDP bone scintigraphy and 18 F-FDG PET/CT for the detection of skeletal metastases.

BACKGROUND: Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is commonly performed for cancer staging, as it can detect metastatic disease in multiple organ systems. However, there has been some controversy in the scientific literature when comparing FDG PET/CT and technetium-99 m-bone scintigraphy (bone scan) for the detection of skeletal metastases. PURPOSE: To compare the accuracy of FDG PET/CT with bone scan for the detection of skeletal metastases. MATERIAL AND METHODS: The study group comprised 202 adult cancer patients who underwent both FDG PET/CT and bone scan within 31 days for staging. Bone scans and FDG PET/CT were evaluated by two musculoskeletal radiologists for the presence and location of skeletal metastatic disease. Confirmation of the final diagnosis was based on the CT or magnetic resonance imaging (MRI) appearance, follow-up imaging, or histology. RESULTS: The sensitivity, specificity, and accuracy for detecting skeletal metastatic disease of FDG PET/CT were 97%, 98%, and 98%, respectively, and of bone scan were 83%, 98%, and 93%, respectively. The lesions that bone scan most commonly missed were located in the pelvis, spine, and sacrum. FDG PET/CT missed mostly lesions that were outside of the field of view, but in all of these cases the patient had additional sites of skeletal metastatic disease. Bone scan falsely identified six metastatic lesions and FDG PET/CT falsely identified three metastatic lesions. CONCLUSION: FDG PET/CT is an accurate technique for detection of skeletal metastases, and is superior to bone scan, especially in the spine and pelvis.

Is Biopsying the Paravertebral Soft Tissue as Effective as Biopsying the Disk or Vertebral Endplate? 10-Year Retrospective Review of CT-Guided Biopsy of Diskitis-Osteomyelitis.

OBJECTIVE: The purpose of this study was to determine whether there is a difference in biopsying bone (endplate), disk, or paravertebral soft tissue to culture the pathogenic organism causing diskitis-osteomyelitis. MATERIALS AND METHODS: A retrospective review was conducted of 111 spinal biopsies performed between 2002 and 2011. Pathologic examination was used as the reference standard for detecting diskitis-osteomyelitis. Microbiologic yield, sensitivity, and specificity were calculated. The yields for different groups were compared by use of Fisher exact test. The analysis was repeated with biopsy samples from patients not being treated with antibiotics at the time of biopsy. RESULTS: A total of 122 biopsy specimens were obtained from 111 spinal biopsy procedures on 102 patients. Overall, 27 (22%) biopsies were performed on the endplate-disk, 61 (50%) on the disk only, and 34 (28%) on paravertebral soft tissue only. The microbiologic yield was 36% for all biopsies, 19% for endplate-disk biopsies, 39% for disk-only biopsies, and 44% for soft-tissue biopsies. The sensitivity and specificity of the microbiologic results for all specimens were 57% and 89%; endplate-disk, 38% and 86%; disk only, 57% and 89%; and paravertebral soft tissue, 68% and 92%. There was no statistically significant difference between the yields of the endplate-disk, disk-only, and paravertebral soft-tissue biopsies. CONCLUSION: Paravertebral soft-tissue changes, when present, may be considered a viable target for biopsy in cases of diskitis-osteomyelitis, even in the absence of a paravertebral abscess.

MRI features of the anterolateral ligament of the knee.

OBJECTIVE: Evaluate the visibility and describe the anatomical features of the anterolateral ligament of the knee using MRI. MATERIALS AND METHODS: Magnetic resonance imaging examinations of the knee were independently reviewed by two musculoskeletal radiologists and assessed for the visibility of the anterolateral ligament under direct cross-referencing of axial and coronal images as complete, partial, or non-visible. Distal insertion site (tibial, meniscal), distance to lateral tibial plateau, measurements (length, width, thickness), and associated imaging findings were also tabulated. Clinical and surgical records were also reviewed. RESULTS: Seventy MRI scans from 60 consecutive subjects were included in the study. Mean age was 40 years, body mass 74.9 kg, and height 1.72 m. The subject population was 53% male, most of the knees were from the left side (51%), and chronic pain was the main clinical symptom (40%). Nine knees (13 %) had undergone previous surgery. The anterolateral ligament was identified in 51% of the knees: completely visible in 11% and partially visible in 40%. In all visible cases, the distal insertion site was identified on the tibia, with a mean distance of 5.7 mm to the plateau. A completely visible ligament had a mean length of 33.2 mm, width of 5.6 mm, and thickness of 1.9 mm [corrected]. Inter-observer agreement for ligament presence was significant (κ = 0.7). Statistical analyses showed a trend to be more visible in men, with a longer length compared with women. CONCLUSIONS: Magnetic resonance imaging clearly identifies the anterolateral ligament of the knee in slightly more than half of cases, being partially visible in most of them. In all cases, a tibial insertion is characterized.

Osteogenic relationship between the lateral plantar process and the peroneal tubercle in the human calcaneus.

The osteogenic relationship between the lateral plantar process and the peroneal tubercle has been an uncertainty for researchers over several decades. While some argue there to be no developmental relationship between these two calcaneal structures, others have suggested that there is an inverse relationship, the lateral plantar process forming from a part of the peroneal tubercle. However, no previous studies have offered quantitative measurements to test these hypotheses. In this study, we measured the size of the peroneal tubercle, retrotrochlear eminence, and the size and area of the lateral plantar process in 73 subjects using magnetic resonance imaging (MRI). Navicular height was measured using weight-bearing radiographs as a measurement of longitudinal arch in 35 of these subjects. Age, body mass, and body mass index (BMI) were also recorded for all subjects. We determined that there was a significant positive correlation between the lateral plantar process and size of the peroneal tubercle, body mass, and BMI. Thus, assertions that there is an inverse relationship between the size of the lateral plantar process and the peroneal tubercle are here unfounded. We also determined there to be a positive correlation between the peroneal tubercle and both the size of the retrotrochlear eminence and the height of the navicular. In conclusion, we relate these novel findings to hominin fossil calcanei and discuss the evolutionary and biomechanical implications.

MRI findings of rotator cuff myotendinous junction injury.

OBJECTIVE: The purpose of this article is to describe the MRI features of rotator cuff myotendinous junction injuries. MATERIALS AND METHODS: We retrospectively identified MRI cases with myotendinous junction injury of the rotator cuff muscles and reviewed clinical, imaging, and surgical records. MR images were reviewed independently by two musculoskeletal radiologists to grade myotendinous junction injuries (strain, partial tear, or complete tear) and to assess for concurrent tendon tears (partial or full thickness) and bone changes (fracture or contusion). RESULTS: The final study group comprised 16 subjects. The mean age was 38 years, with a majority of men (56%). The left shoulder was affected in 56% of subjects, with the dominant upper limb affected in 50%. The mean time between symptoms and MRI was 19 days. Subjects reported heavy lifting (19%), landing on the arm after a fall (19%), or prior shoulder therapeutic injection (25%). Myotendinous junction injuries affected the infraspinatus muscle (50%), followed by the supraspinatus (31%), subscapularis (25%), and teres minor (19%) muscles. About one fifth of subjects presented with more than one muscle affected, and 94% did not present with tears of the corresponding tendons. Most myotendinous junction injuries were strains (80%), followed by partial tears (20%). No complete tears were identified. There was no correlation between myotendinous junction injury and the presence of bone changes or the presence of tendon tears (p > 0.05). CONCLUSION: Rotator cuff myotendinous junction injuries affect mostly the infra-spinatus and supraspinatus muscles, usually in a strain pattern and without tear of the corresponding tendon attachment.

Steroid-induced Kager's fat pad atrophy.

We report a rare case of Kager's fat pad atrophy and fibrosis in a 60-year-old woman 1 year after a steroid injection for Achilles tendinopathy. There are few published reports of steroid-induced atrophy affecting deeper layers of fat tissue. To our knowledge, this case report is the first to illustrate its features using magnetic resonance imaging. A review of the scientific literature is also presented.

T2 relaxometry of the infrapatellar fat pad after arthroscopic surgery.

OBJECTIVE: To investigate the T2 relaxation values of the infrapatellar fat pad (IFP) after arthroscopic surgery. MATERIALS AND METHODS: This study was approved by the institutional review board; all individuals signed informed consent. We performed MRI in 16 knees from 8 subjects. Prior to imaging, each subject had unilateral arthroscopic knee surgery and an asymptomatic non-operated contralateral knee. We used a 10-echo multiple-TE fast-spin echo pulse sequence for creation of T2 relaxation time maps. Two musculoskeletal radiologists independently placed regions of interest in the IFP, suprapatellar subcutaneous and deep intermuscular adipose tissue. Qualitative assessments were performed to assess fibrotic changes affecting patellar retinaculum and IFP. Statistical analyses of T2 values determined differences between groups, correlation with time after surgery, and cut-off values to differentiate groups. RESULTS: The average time between arthroscopy and imaging was 3.5 ± 0.4 years. IFP of knees with prior surgery had significantly shorter mean T2 values (133 ± 14 ms) compared with control knees (147 ± 8 ms, P = 0.03). There was no significant difference between operated and control knees regarding T2 values of suprapatellar subcutaneous (P = 0.3) or deep intermuscular adipose tissue (P = 0.2). There was no correlation between IFP T2 values and time after surgery (P > 0.2). IFP T2 values ≤ 139 ms had 75 % sensitivity and 88 % specificity in identifying prior arthroscopy. CONCLUSION: Shortening of T2 relaxation values is present in IFP chronically after arthroscopic surgery and may be an indicator of adipose tissue fibrosis.

Extrinsic wrist ligaments: prevalence of injury by magnetic resonance imaging and association with intrinsic ligament tears.

OBJECTIVE: The objective of this study was to determine the prevalence of extrinsic wrist ligament injury by magnetic resonance imaging and its association with intrinsic ligament tears. METHODS: We reviewed conventional magnetic resonance images performed over a 5-year period from adult patients in the setting of wrist trauma. Two musculoskeletal radiologists examined the integrity of wrist ligaments and presence of bone abnormalities. RESULTS: In a cohort of 75 subjects, extrinsic ligament injury was present in 75%, with radiolunotriquetral being most frequently affected (45%). Intrinsic ligament injury was present in 60%. Almost half of subjects had combined intrinsic and extrinsic ligament injury. Bone abnormalities were seen in 69%. The rate of extrinsic injury was higher in subjects with bone injury (P = 0.008). CONCLUSIONS: There is high prevalence of extrinsic ligament injury in the setting of wrist trauma, especially in the presence of bone abnormalities, with combined injury of intrinsic and extrinsic ligaments in about half of cases.

Diagnostic yield of CT-guided sampling in suspected sternoclavicular joint infection.

OBJECTIVE: To determine the prevalence of infection diagnosed by percutaneous computed tomography (CT)-guided sternoclavicular (SC) sampling in cases of suspected joint infection. MATERIALS AND METHODS: A retrospective search was performed in reports of SC joint CT-guided biopsies in adults from July 1992 to July 2012. We reviewed medical records, radiology, microbiology, laboratory, and surgical reports. A positive result was defined as demonstration of a pathogenic organism, either by microscopy or growth in culture, confirming the diagnosis of SC joint infection. A negative result was defined as the absence of such findings. Patients in whom sampling was unsuccessful or not subjected to microbiology were excluded. In addition, CT images were reviewed by the consensus of two musculoskeletal radiologists. RESULTS: A total of 41 patients (mean age 57.1 years) underwent CT-guided SC joint sampling, 27 of whom underwent microbiology studies. Sampling was performed using core biopsy alone in 19%, fine needle aspiration alone in 44%, and aspiration combined with core biopsy in 37%. Positive results were found in 52% (14/27) of patients. Related diseases and predisposing conditions for infection were found in 79% of positive patients. Negative results were found in 48% (13/27) of patients. There were no procedure-related complications. The dominant CT findings were soft tissue swelling (negative group), and effusion and/or capsular hypertrophy/distension (positive group). CONCLUSIONS: CT-guided sampling is a safe procedure with positive microbiological cultures in slightly more than half of cases.

Peroneal tendon abnormalities in subjects with an enlarged peroneal tubercle.

OBJECTIVE: To examine the association between inframalleolar peroneal tendon abnormalities and an enlarged peroneal tubercle. MATERIALS AND METHODS: Two independent readers evaluated consecutive ankle MR imaging studies to classify inframalleolar peroneal tendon findings as normal, tenosynovitis, partial tear or complete tear. The size and morphology of the peroneal tubercle was also recorded. We performed statistical analyses for inter-observer agreement and to assess differences in peroneal tubercle size between groups with and without peroneal tendon abnormalities. RESULTS: The study group comprised 121 subjects (mean age, 45.5 years) of whom 28% (34 out of 121) had lateral ankle symptoms. The peroneal tubercle was absent in 56% of subjects (68 out of 121). In subjects with a peroneal tubercle (>0 mm), the mean size was 3.5 mm (37% triangular and 7% plateau-shaped). Male subjects had significantly larger mean peroneal tubercle size than female subjects (2.1 ± 2.5 vs 1.2 ± 1.9 mm, P = 0.04). Overall, 26% (32 out of 121) of subjects had some peroneal tendon abnormality: 17% (20 out of 121) had tenosynovitis and 17 % (20 out of 121) had partial thickness tears. The peroneal tubercle size was significantly larger in subjects with peroneal tendon partial tears (P = 0.036), tenosynovitis (P < 0.001), and when both abnormalities were present (P = 0.007). ROC statistic showed 73% sensitivity and 74% specificity for detection of partial tears for peroneal tubercle size ≥4.3 mm. CONCLUSION: Our study shows a significantly larger peroneal tubercle in subjects with inframalleolar peroneal tendon abnormalities. A cut-off of 4.3 mm showed good sensitivity and specificity for the presence of partial tears of the peroneal tendon.

2-Dimensional and 3-Dimensional MR Imaging-Aid to Knee Preservation Surgery: Focus on Meniscus and Articular Cartilage.

With an increasing life expectancy of global human population, there is a growing demand for preservation of native articular meniscus and cartilage to delay joint arthroplasties, especially in younger and active patients. Since damage to the meniscus and hyaline cartilage of the knee have limited intrinsic capacity to heal, such lesions lead to premature and/or accelerated osteoarthritis. However, knee surgical treatments have evolved and may allow restoration of the natural anatomy, delay the progression of damage, and alter the biology of the meniscus and articular cartilage. The knee preservation surgery is aided by timely detection of such injuries and high-resolution illustration and characterization of the pathology using two-dimensional and three-dimensional magnetic resonance imaging (MRI), made possible due to better MR scanner technology and related software improvements. This article reviews the current literature and authors' experience with imaging concepts and high-resolution MR imaging techniques as they relate to management and planning for such restorative procedures. Relevant arthroscopy correlations have been illustrated.

Neuropathy Score Reporting and Data System (NS-RADS): A Practical Review of MRI-Based Peripheral Neuropathy Assessment.

The Neuropathy Score Reporting and Data System (NS-RADS) is a newly developed MR imaging-based classification that standardizes reporting and multidisciplinary communication for MR imaging diagnosis and follow-up of peripheral neuropathies. NS-RADS classification has shown to be accurate and reliable across different centers, readers' experience levels, and degrees of peripheral neuropathies, which include nerve injury, entrapment, neoplasm, diffuse neuropathy, post-interventional status, and temporal changes in muscle denervation. This article brings a practical review of NS-RADS classification, representative MR cases, and a step-by-step tutorial on how to approach this staging system. Readers can gain knowledge and apply it in their practice, aiming to standardize the communications between specialties and improve patient management.

Advanced Imaging in the Chronic Lateral Ankle Instability: An Algorithmic Approach.

Imaging examinations are a fundamental part of assessing chronic lateral ankle instability (CLAI). Plain radiographs are used in the initial examination, whereas stress radiographs can be requested to actively search for instability. Ultrasonography (US) and Magnetic Resonance Imaging (MRI) allow direct visualization of ligamentous structures, with the advantage of dynamic evaluation for US, and assessment of associated lesions and intra-articular abnormalities for MRI, which plays an essential role in surgical planning. This article reviews imaging methods to diagnose and follow up on CLAI, along with illustrative cases and an algorithmic approach.

Meniscal ramp lesions: an illustrated review.

The purpose of this review is to describe the anatomy and lesions affecting the peripheral portion of posterior horn of medial menisci (ramp lesions), along with illustrations and MRI cases. We will correlate imaging features with arthroscopic classification of ramp lesions. Also, postoperative and chronic changes related to meniscocapsular tears will be presented, as well as biomechanical consequences and treatment approach.