Utility of digital photographs of the hand for assessing the presence of hand osteoarthritis.

OBJECTIVES: Nodal osteoarthritis of the hand (hand OA) is a subset of OA with a strong heritable component. Multiple genetic analyses of this condition have been performed and are underway. Highest yield from any genetic study depends upon a clear clinical phenotype for case definition. Radiographs may provide the most detail about the nature of the lesion. Physical examination is an imperfect means of evaluating each patient, particularly when hundreds or thousands of patients are required for study. Our study evaluated the accuracy, relative to a radiograph, of a digital photograph of the hands for the presence of OA in a particular joint, as well as for the diagnosis of nodal hand OA. METHODS: Consecutive patients were evaluated as part of the I-NODAL study (Investigation of Nodal Osteoarthritis to Detect an Association with Loci encoding Interleukin-1 [IL-1]). Evaluation included a physical examination by a trained rheumatologist, a postero-anterior radiograph of the hands, and a digital photograph of each hand. Radiographs were read by one trained observer using the Kellgren-Lawrence scale. Photographs were taken by one individual and were analyzed by an experienced rheumatologist. Kappa statistics were determined for each modality and accuracy was assessed using radiographic readings as a gold standard. RESULTS: Intra-reader reliability for radiograph interpretation was good for the overall diagnosis of hand OA (kappa0.76 [0.45,1.07]), but varied widely for the presence or absence of K-L grades 2-4 in individual joints (median kappa0.70, range 0.49-0.87 for ACR index joints). Distal interphalangeal joint (DIP) nodes on physical examination were sensitive (median 96.27, 93.94-100), but not specific for radiographic hand OA in the corresponding joint (median 33.0, 17.24-42.86). Physical examination evidence of OA in the 1st carpo-metacarpal (CMC) and proximal interphalangeal (PIP) joints provided only moderate sensitivity and specificity. However, the negative predictive value of the examination of individual joints was good (median negative predictive value was 82.58 for IP joints with a range 68.29-100.00), particularly in the DIP joints. Specificity of a node visualized on hand photograph was variable (median for all IP joints and 1st CMC 83.77, range 53.37-96.97), with greatest specificity for radiographic OA in the corresponding joint found in the 1st CMC and the PIP joints. Clinical hand OA was sensitive, but not specific for the radiographic diagnosis of hand OA; while, photographic OA was moderately specific, but insensitive. CONCLUSION: The visualization of a node on a digital photograph of the hand provides fair to moderate specificity for radiographic hand OA in the corresponding joint, with generally poor sensitivity. A photograph has limited value as a screening tool for the diagnosis of radiographic hand OA.

Association of erosive hand osteoarthritis with a single nucleotide polymorphism on the gene encoding interleukin-1 beta.

OBJECTIVE: Certain forms of primary osteoarthritis (OA), particularly those affecting hand joints, have a genetic component. Recent studies have shown suggestive evidence that hand and knee OA are linked with the interleukin-1 (IL-1) region on human chromosome 2q. This study was undertaken to assess the association of primary OA of the hand (hand OA) with IL-1 region markers. METHODS: Sixty-eight US Caucasoid cases and 51 US Caucasoid controls aged 60 years or older were recruited from the Mid-Atlantic region of the United States. Hand OA was classified by American College of Rheumatology (ACR) Clinical Criteria, and cases were subjected to radiographic examination for subgrouping. Genotyping was done for seven previously described single nucleotide polymorphisms (SNPs) of genes for IL-1alpha (encoded by IL1A), IL-1beta (IL1B), and the IL-1 receptor antagonist (IL1RN), as well as an IL1RN variable number of tandem repeat (VNTR) marker. Six microsatellite markers on other chromosomes (null loci) were also typed. RESULTS: The IL1B 5810 G>A SNP genotypes marker were not in Hardy-Weinberg equilibrium (p<0.05 in both non-erosive and erosive hand OA subgroups). Statistically significant association with the IL1B 5810 AA genotype was found in the erosive hand OA subgroup (relative risk 3.8, p=0.007). This IL1B 5810 AA genotype association was also significant between erosive and non-erosive hand OA subjects (relative risk 4.01, p=0.008). As expected, significant linkage disequilibrium was present between IL1B 5810 SNP and IL1A (-)889 SNP, other IL1B SNPs, and the nearest IL1RN SNP examined. The IL1B 5810A allele occurs most frequently on haplotypes with the SNP alleles IL1B 1423C, IL1B 1903T, IL1B 5887C, and IL1A (-)889C. Genotypes at null loci failed to show evidence suggesting population stratification that might account for spurious association. CONCLUSION: Statistical evidence shows association between erosive hand OA and a genomic region containing the IL1B 5810 SNP in a US Caucasoid population. This supports a potential role for IL-1 in the pathogenesis of a severe phenotype of hand OA.

Imaging findings in Mazabraud's syndrome: seven new cases.

OBJECTIVE: To present seven new cases of Mazabraud's syndrome with particular observations on the magnetic resonance imaging findings and a review of the literature. DESIGN AND PATIENTS: A multi-institutional retrospective review was performed on seven patients with confirmed Mazabraud's syndrome. The patient group was composed of six women and one man, ranging in age from 39 to 65 years, with a mean age of 53 years. RESULTS: Fibrous dysplasia was more often polyostotic ( n=6) and right-sided ( n=4). Fibrous dysplasia involved the femur in five cases. The soft tissue myxomas were multiple in four cases and were intramuscular in origin. The most commonly affected location was the thigh ( n=4). On computed tomography, myxomas were well-circumscribed, low-attenuation masses. On magnetic resonance images, the lesions were significantly low in signal intensity on T1-weighted images and high in signal intensity on T2-weighted images relative to adjacent skeletal muscle. Enhancement of the myxomas was heterogeneous with irregular, peripheral rim enhancement, and a variable degree of central enhancement depending on the abundance of solid myxoid tissue and bridging fibrous septa. CONCLUSIONS: Knowledge of Mazabraud's syndrome and the imaging appearance of intramuscular myxoma is important in order to avoid unnecessary biopsies of the osseous and soft tissue lesions. The unique features of this disorder allow discrimination from soft tissue malignancies such as sarcoma.

Clinical imaging of articular cartilage in the knee.

Assessment of articular cartilage has become an essential part of magnetic resonance (MR) evaluation of the knee. This has occurred because of recent advances in treatment along with improved accuracy of MR image evaluation of articular cartilage. Detection of articular cartilage defects can provide an explanation for symptoms and allow identification of patients for cartilage therapy and is an important factor for predicting prognosis of patients with knee injury. This review describes the most easily implemented MR techniques for evaluation of articular cartilage and the normal and abnormal appearance of cartilage seen using these techniques. The influence of imaging findings on treatment is described.

Magnetic resonance imaging of articular cartilage.

Magnetic resonance imaging is the optimal modality for assessing articular cartilage because of superior soft tissue contrast, direct visualization of articular cartilage, and multiplanar capability. Despite these advantages, there has been disagreement as to the efficacy of magnetic resonance imaging of articular cartilage. The reason for this controversy is multifactorial but in part is attributable to the lack of the use of optimized pulse sequences for articular cartilage. The current authors will review the current state of the art of magnetic resonance imaging of articular cartilage and cartilage repair procedures, discuss future new directions in imaging strategies and methods being developed to measure cartilage thickness and volume measurements, and propose a magnetic resonance imaging protocol to evaluate cartilage that is achievable on most magnetic resonance scanners, vendor independent, practical (time and cost efficient), and accepted and used by a majority of musculoskeletal radiologists.

Magnetic resonance imaging of articular cartilage of the knee.

Recently developed magnetic resonance (MR) imaging techniques allow accurate detection of moderate- and high-grade articular cartilage defects. There has been increased interest in MR imaging of articular cartilage in part because it is useful in identifying patients who may benefit from new articular cartilage replacement therapies, including chondrocyte transplantation, improved techniques for osteochondral transplantation, chondroprotective agents, and cartilage growth stimulation factors. The modality also has the potential to play an important role in the follow-up of patients during and after treatment. Detection of articular cartilage defects is beneficial for patients undergoing arthroscopy for other injuries, such as meniscal tears, because the presence of articular cartilage injury worsens prognosis and may modify therapy options.

Bone marrow edema in the greater tuberosity of the humerus at MR imaging: association with rotator cuff tears and traumatic injury.

UNLABELLED: The purpose of this study was to determine the prevalence of bone marrow edema in the greater tuberosity of the humerus on MR imaging, the association with other findings at MR imaging and the injury mechanism which can lead to this finding. SUBJECTS AND METHODS: MR reports from 863 patients referred for shoulder MRI over 74 months were reviewed to identify patients with marrow edema in the greater tuberosity. The MR images from patients with greater tuberosity marrow edema were reviewed by consensus of two radiologists for the extent of marrow edema and for associated injuries. Marrow edema in the greater tuberosity was seen in 11 of 863 patients (1.3%). Nine patients (82%) had associated rotator cuff tear by MR imaging (four full thickness and five partial thickness), one patient had avulsion of the greater tuberosity from the humerus, and one had no rotator cuff abnormality. History of trauma was reported by eight patients including fall without direct blow to the shoulder (6), car accident (1) and direct blow to the top of the shoulder (1). Marrow edema in the greater tuberosity is an infrequent finding. Marrow edema most often is associated with a history of trauma and with rotator cuff abnormalities including full thickness tears. The history of trauma without direct blow to the shoulder and the location of the edema indicates that marrow edema often results from avulsion injury by the supraspinatus tendon.

Neuropathic osteoarthropathy: diagnostic dilemmas and differential diagnosis.

The purpose of this pictorial essay is to illustrate the radiologic spectrum of imaging findings of neuropathic osteoarthropathy. Typical findings include joint destruction, disorganization, and effusion with osseous debris. A variety of other imaging findings related to neuropathic osteoarthropathy such as resorption of the ends of tubular bones and neuropathic fracture are shown. The two prevailing theories for the pathophysiology of neuropathic bone and joint disease, the neurovascular and neurotraumatic theories, are briefly described. Examples of osteoarthropathy from diverse causes are presented including syringomyelia, spinal cord injury, meningomyelocele, diabetes mellitus, congenital insensitivity to pain, steroid injections, syphilis, leprosy, and others. The discussion focuses on key imaging features with emphasis on disease patterns and differential diagnosis, which vary by skeletal location.

Abnormal signal intensity in skeletal muscle at MR imaging: patterns, pearls, and pitfalls.

Abnormal signal intensity within skeletal muscle is frequently encountered at magnetic resonance (MR) imaging. Potential causes are diverse, including traumatic, infectious, autoimmune, inflammatory, neoplastic, neurologic, and iatrogenic conditions. Alterations in muscle signal intensity seen in pathologic conditions usually fall into one of three recognizable patterns: muscle edema, fatty infiltration, and mass lesion. Muscle edema may be seen in polymyositis and dermatomyositis, mild injuries, infectious myositis, radiation therapy, subacute denervation, compartment syndrome, early myositis ossificans, rhabdomyolysis, and sickle cell crisis. Fatty infiltration may be seen in chronic denervation, in chronic disuse, as a late finding after a severe muscle injury or chronic tendon tear, and in corticosteroid use. The mass lesion pattern may be seen in neoplasms, intramuscular abscess, myonecrosis, traumatic injury, myositis ossificans, muscular sarcoidosis, and parasitic infection. Some of these conditions require prompt medical or surgical management, whereas others do not benefit from medical intervention. The ability to accurately diagnose these conditions is therefore necessary, and biopsy may be required to establish the correct diagnosis. Clues to the correct diagnosis and whether biopsy is necessary or appropriate are often present on the MR images, especially when they are correlated with clinical features and the findings from other imaging modalities.

MR imaging of articular cartilage.

With the advent of new treatments for articular cartilage disorders, accurate noninvasive assessment of articular cartilage, particularly with MR imaging, has become important. Understanding the MR imaging features of articular cartilage has led to the development of two types of routinely available MR imaging techniques which have demonstrated clinical accuracy and interobserver reliability.

Articular cartilage defects: in vitro evaluation of accuracy and interobserver reliability for detection and grading with US.

PURPOSE: To determine the accuracy and reliability of detecting and grading articular cartilage defects in porcine and human knees by using ultrasonography (US). MATERIALS AND METHODS: US was used to evaluate 175 porcine and 16 human knee surfaces with a linear 5-12-MHz transducer. Porcine defects of varying diameter and depth were surgically created. Each porcine surface was independently assessed in blinded fashion by two radiologists for the presence and severity of defects. Accuracy of detection, interobserver reliability, and concordance between US and surgical grades were determined. Human specimens were retrieved from knees of patients who underwent joint arthroplasty. Defects in human knees detected with US were correlated with defects seen at direct surface visualization. RESULTS: Sensitivities for detection of porcine defects were 94% and 93% for readers 1 and 2, respectively; specificities were 90% and 77%, respectively; positive predictive values were 98% and 95%, respectively; and negative predictive values were 78% and 73%, respectively. Interobserver agreement was high (weighted kappa = 0.80), and concordance between US and surgical grades for both readers was high (weighted kappa = 0.90 and 0.78). In human cartilage, the distribution of cartilage denudation determined at US was the same as that determined at direct visualization. CONCLUSION: High-frequency US was accurate and reliable for detection and grading of knee articular cartilage defects.

Metaphyseal undertubulation in gaucher disease: resolution at MRI in a patient undergoing enzyme replacement therapy.

Gaucher disease is a sphingolipid storage disorder that results in the accumulation of Gaucher cells within the reticuloendothelial system. The life span can be near normal in the most common form. Our case illustrates the resolution of the skeletal findings in Gaucher disease following enzyme replacement therapy. We also report the correlation of these findings with clinical improvement.

Screening for avascular necrosis of the hip with rapid MRI: preliminary experience.

PURPOSE: The purpose of this work was to compare rapidly acquired MR images with routinely employed SE and turbo SE (TSE) images in screening for hip avascular necrosis (AVN). METHOD: Twelve patients with findings suspicious for radiographically occult AVN of one or both hips were studied with our routine screening protocol (imaging time >7 min) and similarly weighted, rapidly acquired MR sequences (imaging time <1 min). RESULTS: The rapidly acquired MR images were judged to be similar to the routine protocol in demonstrating marrow edema, irregular lines within the femoral head characteristic of AVN, and osteoarthritis. CONCLUSION: The rapidly acquired MR sequences that we studied reliably revealed the presence or absence of AVN, marrow edema, and osteoarthritis of the hip in our sample population when compared with SE and TSE sequences that we routinely perform. Further investigation of rapidly acquired MR sequences is warranted, as imaging time may be dramatically reduced and patient throughput increased.

Internal derangements of the knee: rates of occurrence at MR imaging in patients referred by orthopedic surgeons compared with rates in patients referred by physicians who are not orthopedic surgeons.

PURPOSE: To compare the occurrence at magnetic resonance (MR) imaging of clinically important knee abnormalities in patients referred by orthopedic surgeons with that in patients referred by other physicians. MATERIALS AND METHODS: Knee MR images in all patients referred for evaluation of internal derangement for 12 months were retrospectively reviewed. Meniscus, ligament, and articular cartilage abnormalities were tabulated. The numbers of abnormalities detected in the patients referred by orthopedic surgeons were compared with those in the patients referred by all other physicians by using chi(2) analysis. Significance was defined at P less than .05. RESULTS: Knee MR images in 439 patients were reviewed; 328 patients were referred by orthopedic surgeons, and 111 were referred by other physicians. There was no significant difference in the rates of occurrence of meniscus tear (149 [45%; orthopedic surgeon referrals] vs 50 [45%; other physician referrals], P = .96); ligament tear (82 [25%] vs 21 [19%], P = .25); isolated hyaline cartilage defect (77 [23%] vs 20 [18%], P = .29); meniscus or ligament tear (167 [51%] vs 55 [50%], P = .86); or meniscus, ligament, or articular cartilage tear (242 [74%] vs 72 [65%], P = .34). The proportion of patients who subsequently underwent surgery of the knee was also similar (39% [118 of 300] vs 28% [23 of 82], P = .14). CONCLUSION: There was no significant difference in the occurrences of clinically important knee internal derangement at MR imaging between patients referred by orthopedic surgeons and those referred by other physicians.

Osseous hemangiopericytomas of unsuspected intracranial origin.

Two cases of osseous hemangiopericytoma are presented that were initially diagnosed as primary in origin, but later reclassified as metastases, after a history of resection for an intracranial tumor was discovered. An intracranial source should be excluded before an isolated osseous tumor is determined to be a primary hemangiopericytoma.