Hypertrophic Osteoarthropathy: Clinical and Imaging Features.

Hypertrophic osteoarthropathy (HOA) is a medical condition characterized by abnormal proliferation of skin and periosteal tissues involving the extremities and characterized by three clinical features: digital clubbing (also termed Hippocratic fingers), periostosis of tubular bones, and synovial effusions. HOA can be a primary entity, known as pachydermoperiostosis, or can be secondary to extraskeletal conditions, with different prognoses and management implications for each. There is a high association between secondary HOA and malignancy, especially non-small cell lung cancer. In such cases, it can be considered a form of paraneoplastic syndrome. The most prevalent secondary causes of HOA are pulmonary in origin, which is why this condition was formerly referred to as hypertrophic pulmonary osteoarthropathy. HOA can also be associated with pleural, mediastinal, and cardiovascular causes, as well as extrathoracic conditions such as gastrointestinal tumors and infections, cirrhosis, and inflammatory bowel disease. Although the skeletal manifestations of HOA are most commonly detected with radiography, abnormalities can also be identified with other modalities such as computed tomography, magnetic resonance imaging, and bone scintigraphy. The authors summarize the pathogenesis, classification, causes, and symptoms and signs of HOA, including the genetics underlying the primary form (pachydermoperiostosis); describe key findings of HOA found at various imaging modalities, with examples of underlying causative conditions; and discuss features differentiating HOA from other causes of multifocal periostitis, such as thyroid acropachy, hypervitaminosis A, chronic venous insufficiency, voriconazole-induced periostitis, progressive diaphyseal dysplasia, and neoplastic causes such as lymphoma. ©RSNA, 2016.

MR anatomy and pathology of the ulnar nerve involving the cubital tunnel and Guyon's canal.

Ulnar neuropathy is a common and frequent reason for referral to hand surgeons. Ulnar neuropathy mostly occurs in the cubital tunnel of the elbow or Guyon's canal of the wrist, and it is important for radiologists to understand the imaging anatomy at these common sites of impingement. We will review the imaging and anatomy of the ulnar nerve at the elbow and wrist, and we will present magnetic resonance imaging examples of different causes of ulnar neuropathy, including trauma, overuse, arthritis, masses and mass-like lesions, and systemic diseases. Treatment options will also be briefly discussed.

Effects of contralateral versus ipsilateral cane use on gait in people with knee osteoarthritis.

OBJECTIVE: To compare the immediate effects of contralateral versus ipsilateral cane use on spatiotemporal gait parameters and peak vertical ground force in overweight or obese adults with symptomatic knee osteoarthritis (OA). DESIGN: Prospective observational study. SETTING: An academic tertiary Veterans Affairs Healthcare Center. PARTICIPANTS: Thirty-eight overweight or obese subjects with symptomatic knee OA who had not used a cane for the past 30 days. METHODS: Spatiotemporal gait data were obtained with an optical motion capture system while subjects walked without a cane, with a cane contralateral to the more painful lower limb, or with a cane ipsilateral to the more painful lower limb at self-selected speeds. An in-shoe dynamic pressure distribution system was used to measure the vertical ground reaction force. MAIN OUTCOME MEASUREMENTS: Spatiotemporal measures of gait and peak vertical ground reaction force on both lower limbs were recorded for each walking condition: no cane, contralateral cane, and ipsilateral cane. RESULTS: Walking with a cane either contralateral or ipsilateral to the more symptomatic limb led to significant reductions in gait velocity (14%-16%), cadence (12%-14%), and peak vertical ground reaction force (normalized for body weight; 11%-12%) on the more painful lower limb compared with walking unaided (P < .05). There were no significant differences in the peak vertical ground reaction force on either lower limbs when comparing walking with a cane contralateral to the more painful limb or walking with a cane ipsilateral to the more painful limb. Subjects also experienced a significant decrease in gait velocity with contralateral or ipsilateral cane use compared with walking without a cane; the lower walking speed was due to a decrease in cadence. CONCLUSIONS: These results support the prescription of a single-point cane to offload a lower limb with painful knee OA by holding the cane either ipsilateral or contralateral to the more painful lower limb.

Musculoskeletal manifestations of endocrine disorders.

Endocrine disorders can lead to disturbances in numerous systems within the body, including the musculoskeletal system. Radiological evaluation of these conditions can demonstrate typical appearances of the bones and soft tissues. Knowledge of these patterns can allow the radiologist to suggest a diagnosis that may not be clinically apparent. This review will highlight the typical musculoskeletal findings of acromegaly, hypercortisolism, hyperthyroidism, hypothyroidism, hyperparathyroidism, pseudo- and pseudopseudohypoparathyroidism, and diabetes mellitus. The radiological manifestations of each of these endocrine disorders, along with a brief discussion of the pathophysiology and clinical implications, will be discussed.

The Morel-Lavallée lesion: pathophysiology, clinical presentation, imaging features, and treatment options.

Morel-Lavallée lesions are posttraumatic hemolymphatic collections related to shearing injury and disruption of interfascial planes between subcutaneous soft tissue and muscle. We review the pathophysiology of Morel-Lavallée lesions, clinical presentation, and potential sites of involvement. Magnetic resonance imaging (MRI) is the modality of choice for characterization. We present the MRI classification and highlight the key imaging features that distinguish the different types, focusing on the three most common: seroma, subacute hematoma, and chronic organizing hematoma. Potential mimics of Morel-Lavallée lesions, such as soft tissue sarcoma and hemorrhagic prepatellar bursitis, are compared and contrasted. Treatment options and a management algorithm are also briefly discussed.

Clinical and spatiotemporal gait effects of canes in hip osteoarthritis.

OBJECTIVE: To investigate the effects of cane use on spatiotemporal gait parameters, pain, and function in adults with hip osteoarthritis (OA). DESIGN: Prospective observational study. SETTING: An academic tertiary Veterans Affairs Healthcare Center. PARTICIPANTS: Thirteen adults with symptomatic hip OA and 13 healthy adults. METHODS: We undertook gait analysis in all subjects with an optoelectronic camera system. Pain, stiffness, and physical function in subjects with hip OA were assessed with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). MAIN OUTCOME MEASUREMENTS: Baseline spatiotemporal measures of unaided gait were obtained for healthy subjects. Baseline and 4-week spatiotemporal gait parameters were assessed for hip OA subjects while they walked with and without a cane. Participants with hip OA completed the WOMAC at baseline and after 4 weeks of cane use. RESULTS: At baseline when walking unaided, the subjects with hip OA (age range 60-75 years) had a significantly slower gait velocity, shorter affected limb stride length, and longer double-stance time compared with healthy control subjects. When walking with a cane, they had a reduction in gait velocity (P < .05) caused by a decrease in cadence (P < .05) compared with walking unaided. After 4 weeks of cane use, the participants with hip OA demonstrated significant improvements in gait velocity (P < .05) and double-stance time (P < .05) when walking with a cane in comparison with baseline data. There was no improvement in pain and function after 4 weeks of cane use, a period in which only approximately 60% of the hip OA subjects used the cane 6 or more times per week. CONCLUSIONS: Initial use of a cane led to decreased gait velocity and cadence in people with hip OA compared with walking unaided. This difference in gait velocity diminished after they practiced walking with the cane. Inconsistent use of the cane may have contributed to the lack of improvement in the subjects' hip OA pain and function.

Sclerosing bone dysplasias: review and differentiation from other causes of osteosclerosis.

Sclerosing bone dysplasias are skeletal abnormalities of varying severity with a wide range of radiologic, clinical, and genetic features. Hereditary sclerosing bone dysplasias result from some disturbance in the pathways involved in osteoblast or osteoclast regulation, leading to abnormal accumulation of bone. Several genes have been discovered that, when disrupted, result in specific types of hereditary sclerosing bone dysplasia (osteopetrosis, pyknodysostosis, osteopoikilosis, osteopathia striata, progressive diaphyseal dysplasia, hereditary multiple diaphyseal sclerosis, hyperostosis corticalis generalisata), many of which exhibit similar pathologic mechanisms involving endochondral or intramembranous ossification and some of which share similar underlying genetic defects. Nonhereditary dysplasias include intramedullary osteosclerosis, melorheostosis, and overlap syndromes, whereas acquired syndromes with increased bone density, which may simulate sclerosing bone dysplasias, include osteoblastic metastases, Paget disease of bone, Erdheim-Chester disease, myelofibrosis, and sickle cell disease. Knowledge of the radiologic appearances, distribution, and associated clinical findings of hereditary and nonhereditary sclerosing bone dysplasias and acquired syndromes with increased bone density is crucial for accurate diagnosis.

Effects of footwear on medial compartment knee osteoarthritis.

This pilot study investigated whether lateral-wedge insoles inserted into shock-absorbing walking shoes altered joint pain, stiffness, and physical function in patients with symptomatic medial compartment knee osteoarthritis (OA). Twenty-eight subjects wore full-length lateral-wedge insoles with an incline of 4 degrees in their walking shoes for 4 weeks. Pain, stiffness, and functional status were measured with the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index at baseline and 4 weeks postintervention. Significant improvements were observed in all three WOMAC subscales (pain, stiffness, and function). Pain scores were significantly reduced for the most challenging activity-stair climbing. Subjects wore insoles daily and tolerated them well. The results of this study indicated that lateral-wedge insoles inserted into shock-absorbing walking shoes are an effective treatment for medial compartment knee OA.

Imaging of pigmented villonodular synovitis.

Pigmented villonodular synovitis (PVNS) is a rare, benign, idiopathic proliferative disorder of the synovium that results in villous and/or nodular formation in joints, tendon sheaths, and bursae. The disease can be localized or diffuse. Patients with this condition typically present with symptoms of mild discomfort and associated stiffness of the involved joint; however, the spectrum of presentations is broad. Diagnosis of PVNS can be clinically difficult, and plain radiographs are usually nonspecific. Magnetic resonance (MR) imaging is a highly diagnostic modality in characterizing PVNS when it contains hemosiderin deposits exhibiting low signal intensity on all MR image pulse sequences. This article discusses the presentation, pathology, differential diagnosis, diagnostic modalities as well as various treatment options of PVNS.

MR imaging of soft-tissue masses of the foot.

As with other parts of the musculoskeletal system, the soft tissues of the foot can be affected by a wide variety of pathologic entities including trauma, congenital abnormalities, infections, and neoplastic disorders. While plain radiographs are usually the initial examination for evaluation of pathology, magnetic resonance imaging (MRI) is critical to evaluate for abnormalities within the ligaments, tendons, and other nonosseous structures within the foot. The constellation of clinical and MRI findings often allows a relatively specific diagnosis to be rendered. This article discusses both benign and malignant processes within the soft tissues of the foot and presents their characteristic imaging findings with MRI.