Percutane Image-Guided Cryoablation of Painful Osseous Metastases: A Retrospective Single-Center Review.

PURPOSE: Painful osseous metastases are a common problem in patients with malignancy, and they can be associated with significant morbidity owing to immobility, pain, pathologic fracture, or neurovascular compromise or all of these. We retrospectively evaluated pain levels and tumor enhancement in patients who underwent palliative percutaneous cryoablation for painful bone metastasis. METHODS: In this institutional review board-approved, health insurance portability and accountability act-compliant study, we retrospectively searched our department׳s picture archiving system for patients who underwent computed tomography (CT)-guided percutaneous cryoablation for treatment of painful metastatic osseous disease over a 6-year period (1/1/2005-12/31/2011). The preprocedure and postprocedure images and imaging reports, primary tumor type, CT-guided cryoablation procedure details, treated tumor response, immediate and 3-month postprocedure complications, reported pain response to cryoablation, postprocedural tumor imaging characteristics, and imaging response of noncryoablated systemically treated metastatic lesions were reviewed in patients with metastatic osseous disease who underwent cryoablation. RESULTS: All 16 patients reported improvement in pain within 1 week after the procedure and at 3-month clinical follow-up. A total of 6.2% had tumor growth and 93.8% had tumor arrest or shrinkage on follow-up CT, although all study patients had progression of noncryoablated metastases at other sites despite systemic therapy. A total of 62.5% of patients with posttreatment contrasted CT demonstrated marginal enhancement at the ablation site, although only single patient had interval growth. CONCLUSION: Most of our patients had tumor arrest or shrinkage on follow-up imaging, despite progression of noncryoablated metastases treated with preprocedure and postprocedure systemic therapy. Radiation therapy, chemotherapy, and analgesics have a moderate failure rate and require repeat treatments where quality of life is the foremost objective. CT-guided cryoablation is a safe palliative treatment to reduce pain in patients with painful osseous metastatic disease, achieve effective local tumor control, and in some cases, provide a curative option for a target lesion.

Imaging of the subtalar joint.

Imaging of the subtalar joint can be challenging because of its complex planar anatomy. This article reviews the anatomy and common anatomic variants as seen with different imaging techniques. Although radiography remains the initial mode of imaging, computed tomography and MRI are frequently needed to better delineate the joint anatomy and improve the sensitivity and the specificity of detection of joint pathology. A short review of arthrographic techniques and various examples of imaging of common pathology involving this joint are also included.

MRI findings of serous atrophy of bone marrow and associated complications.

OBJECTIVES: To report the MRI appearance of serous atrophy of bone marrow (SABM) and analyse clinical findings and complications of SABM. METHODS: A retrospective search of MRI examinations of SABM was performed. Symptoms, underlying conditions, MRI findings, delay in diagnosis and associated complications were recorded. RESULTS: We identified 30 patients (15 male, 15 female; mean age: 46 ± 21 years) with MRI findings of SABM. Underlying conditions included anorexia nervosa (n = 10), cachexia from malignant (n = 5) and non-malignant (n = 7) causes, massive weight loss after bariatric surgery (n = 1), biliary atresia (n = 1), AIDS (n = 3), endocrine disorders (n = 2) and scurvy (n = 1). MRI showed mildly hypointense signal on T1- weighted and hyperintense signal on fat-suppressed fluid-sensitive images of affected bone marrow in all cases and similar signal abnormalities of the adjacent subcutaneous fat in 29/30 cases. Seven patients underwent repeat MRI due to initial misinterpretation of bone marrow signal as technical error. Superimposed fractures of the hips and lower extremities were common (n = 14). CONCLUSIONS: SABM occurs most commonly in anorexia nervosa and cachexia. MRI findings of SABM are often misinterpreted as technical error requiring unnecessary repeat imaging. SABM is frequently associated with fractures of the lower extremities. KEY POINTS: • SABM occurs in several underlying conditions, most commonly anorexia nervosa and cachexia. • Abnormal marrow signal is often misinterpreted as technical error requiring unnecessary repeat imaging. • SABM is frequently associated with stress fractures. • Fractures in SABM can be obscured by marrow signal abnormality on MRI.

The role of pubic symphyseal CT arthrography in the imaging of athletic pubalgia.

OBJECTIVE: The purpose of this article is to describe the results of pubic symphyseal CT arthrography compared with MRI in patients with suspected athletic pubalgia. MATERIALS AND METHODS: In this study, two musculoskeletal radiologists retrospectively searched our department's PACS to identify patients who had undergone CT-guided injection with concurrent pubic symphyseal CT arthrography for evaluation and treatment of groin pain, sports hernia, or athletic pubalgia over a 5.5-year period (January 1, 2007-July 1, 2012). The MR and CT arthrography images and reports, clinical findings at presentation, pain response to injection, and operative findings were reviewed using the electronic medical record. RESULTS: Twelve patients underwent CT-guided injection and pubic symphyseal CT arthrography at our institution during the 5.5-year study period. Nine of the 12 patients had undergone MRI before the procedure. In two of the three patients who had not undergone MRI, CT arthrography revealed secondary clefts. Three of four patients who had secondary clefts on MRI had contrast extravasation reproducing the cleft at CT. Three patients had MRI findings suggestive of athletic pubalgia without MRI evidence of a secondary cleft; in all three of these patients, CT arthrography showed a secondary cleft. In four patients, CT arthrography revealed tendon tears at the adductor origin that were not apparent on MRI. All 12 patients reported decreased groin pain after injection. CONCLUSION: Pubic symphyseal CT arthrography is a useful technique for the diagnosis and short-term pain relief of athletic pubalgia. It can be used to identify secondary clefts and to detect tendon tears that can potentially be overlooked on MRI.

Isolated fractures of the trapezoid as a sports injury.

The aim of this work is to describe the radiographic findings of isolated trapezoid fractures and determine the utility of these findings in guiding treatment. A second aim is to heighten awareness of an uncommon sports-related injury that is often radiographically occult because of the lack of primary or overt secondary radiographic findings. A retrospective review of radiology reports at our institution from 2007 to 2010 was performed to identify isolated trapezoid fractures. Two musculoskeletal radiologists and one orthopedic hand surgeon reviewed the patient presentations, images, treatments, and outcomes of the patients' injuries. This project had institutional review board approval. We describe three patients who presented with isolated sports-related trapezoid fractures. Each patient was successfully treated with activity modification, cast immobilization, and/or surgery based on their specific radiographic findings. Isolated sports-related trapezoid fractures are rare injuries. Only one prior case report in the English literature exists. Treatment success in patients with trapezoid fractures depends upon the degree of activity modification, splint protection, and especially fragment displacement. We report the largest series to date of isolated trapezoid fractures, all of which resulted from sports participation, and we analyze the success of diagnostic and treatment interventions.

Intracranial meningeal hemangiopericytoma metastatic to the scapula.

Meningeal hemangiopericytomas are rare vascular tumors that have a propensity for recurrence and metastasis. Intracranial hemangiopericytomas are rare vascular tumors. They account for 0.5% of primary central nervous system tumors and 2% of meningiomas. Unlike usual benign meningiomas, which rarely metastasize extracranially, meningeal hemangiopericytoma has a high rate of local recurrence and distant metastasis. The treatment paradigms for hemangiopericytomas and meningiomas differ based on their biological behaviors. Hemangiopericytomas have higher rates of recurrence and metastasis compared with meningiomas. Intracranial meningeal hemangiopericytoma is characterized by clinically repeated local recurrences at the primary site. Bone, liver, lung, central nervous system, and abdominal cavity are the most commonly reported sites of metastasis in hemangiopericytomas.This article describes a case of bone metastasis with extensive involvement of the scapula from intracranial hemangiopericytoma. Bone metastasis can be seen in a relatively late phase of the disease, with metastasis to other organs. Although radiation therapy is effective in controlling pain from bone metastases in unresectable disease and those with extensive visceral metastases, aggressive local surgical control of a solitary bone metastasis may be an option for patients with limited distant disease. The diagnosis may be initially confused with clear cell meningioma and benign meningiomas. The management of bone metastasis is not well reported in the orthopedic literature.

Validation of diagnostic codes for subtrochanteric, diaphyseal, and atypical femoral fractures using administrative claims data.

Administrative claims databases have large samples and high generalizability. They have been used to evaluate associations of atypical femoral fractures with bisphosphonates. We developed and assessed accuracy of claims-based algorithms with hospital and physician diagnosis codes for these fractures. Medical records and radiology reports of all adults admitted at University of Alabama at Birmingham Health System from 2004 to 2008 with International Classification of Diseases, Ninth Revision hospital discharges and surgeons' fracture repair codes for subtrochanteric femoral fractures and random sample of other femoral fractures were reviewed. We identified 137 persons with suspected subtrochanteric femoral fractures and randomly selected 50 persons with either suspected diaphyseal femoral fractures or hip fractures other than subtrochanteric and diaphyseal femoral fractures (typical hip fractures). Eleven patients had radiographic features indicative of atypical femoral fractures. The positive predictive value (PPV) of claims-based algorithms varied with primary or secondary positions on discharge diagnoses and the sources of diagnosis codes. The PPV for fractures ranged 69-89% for subtrochanteric femoral, 89-98% for diaphyseal femoral, and 85-98% for typical hip fractures. The PPV of administrative codes for defining a femoral fracture as atypical was low and imprecise. Claims-based algorithms combining hospital discharges with surgeon's diagnosis codes had high PPV to identify the site of subtrochanteric or diaphyseal femoral fractures vs typical hip fractures. However, claims-based data were not accurate in identifying atypical femoral fractures. These claims algorithms will be useful in future population-based observational studies to evaluate associations between osteoporosis medications and subtrochanteric and diaphyseal femoral fractures.

Assessing rheumatoid arthritis with ultrasound of the hands.

OBJECTIVE: The purpose of this video article is to show the sonographic techniques and findings in evaluating the joints of the hands in patients with possible inflammatory arthritis and to review the sonographic appearance and grading of synovitis. CONCLUSION: This video article shows the value of a targeted approach for musculoskeletal ultrasound of the hand and wrist in patients with rheumatoid arthritis. On completion of this video article, the participant should be able to develop an appropriate diagnostic and therapeutic approach using ultrasound for the treatment of patients with rheumatoid arthritis.

Imaging of nerve entrapment in the foot and ankle.

Neuropathies can be a cause of chronic foot and ankle pain. The diagnosis can be elusive given the sometimes nonspecific clinical presentation. Although electrodiagnostic studies are primarily relied on for the diagnosis of nerve impairment, imaging is sometimes helpful in helping define the exact site of the entrapment and whether any masses are present. It is critical for the imager to understand the complex anatomy of these nerves and their adjacent structures, to know the most common locations for their entrapments or injury, and to select the proper imaging modality to improve detection of these difficult-to-diagnose clinical conditions.

Intramyocellular lipid and insulin resistance: differential relationships in European and African Americans.

Insulin resistance has been associated with the accumulation of fat within skeletal muscle fibers as intramyocellular lipid (IMCL). Here, we have examined in a cross-sectional study the interrelationships among IMCL, insulin sensitivity, and adiposity in European Americans (EAs) and African Americans (AAs). In 43 EA and 43 AA subjects, we measured soleus IMCL content with proton-magnetic resonance spectroscopy, insulin sensitivity with hyperinsulinemic-euglycemic clamp, and body composition with dual-energy X-ray absorptiometry. The AA and EA subgroups had similar IMCL content, insulin sensitivity, and percent fat, but only in EA was IMCL correlated with insulin sensitivity (r = -0.47, P < 0.01), BMI (r = 0.56, P < 0.01), percent fat (r = 0.35, P < 0.05), trunk fat (r = 0.47, P < 0.01), leg fat (r = 0.40, P < 0.05), and waist and hip circumferences (r = 0.54 and 0.55, respectively, P < 0.01). In a multiple regression model including IMCL, race, and a race by IMCL interaction, the interaction was found to be a significant predictor (t = 1.69, DF = 1, P = 0.0422). IMCL is related to insulin sensitivity and adiposity in EA but not in AA, suggesting that IMCL may not function as a pathophysiological factor in individuals of African descent. These results highlight ethnic differences in the determinants of insulin sensitivity and in the pathogenesis of the metabolic syndrome trait cluster.

Association of the presence of bone bars on radiographs and low bone mineral density.

OBJECTIVE: Bone bars (BB) are struts of normal trabecular bone that cross the medullary portions of the metaphysis and diaphysis at right angles to the long axis of the shaft. The purpose of this investigation was to determine whether the presence of bone bars (BB) identified on radiographs of the proximal femurs and tibia, predict lower bone mineral density (BMD) as evaluated with dual-energy x-ray absorptiometry (DXA) in the lumbar spine, total hip, or femoral neck. MATERIALS AND METHODS: A total of 134 sequential DXA patients underwent radiography of the pelvis, hips, and both knees. The radiographs were evaluated for the presence of BB by two musculoskeletal radiologists who were blinded to DXA results. A t test was used to evaluate the relationship of BB to BMD and a Chi-square test was used to determine if BB were equally distributed among the categories of normal BMD, low bone mass (osteopenia), and osteoporosis. RESULTS: BB were associated with lower BMD at all measured sites. BB at the intertrochanteric and proximal tibial sites were the most predictive of low BMD while supraacetabular and distal femur BB were less predictive. Osteoporosis or osteopenia is seen in 60-91% of those with BB depending on the side and reader. It is only seen in about 40% of those without BB. CONCLUSIONS: We conclude that the presence of BB suggest decreased BMD and when correlated with other clinical information, might support further evaluation of BMD.

Distribution of Z-scores in a University cohort with an emphasis on "high" bone mineral density.

High bone mineral density (BMD) is currently not defined by the International Society for Clinical Densitometry with a specific Z-score cutoff; however, it has been suggested that a Z-score greater than or equal to 2.5 is not normal. Institutional Review Board approval was obtained. We evaluated a University dual-energy X-ray absorptiometry database over the previous 24 mo to define Z-score distributions. A Z-score greater than or equal to 2.5 was selected as the outcome event of interest in a logistic regression for adjusted odds ratio. The covariates were height; weight; body mass index (BMI); gender; menopausal status; use of female hormones; presence of insufficiency fractures after 50 yr of age; previous fractures; previous surgeries (back surgeries, vertebroplasty, or kyphoplasty); transplant history; presence of long-term chronic conditions (asthma, lupus, rheumatoid arthritis, or cystic fibrosis); eating disorder; current use of glucocorticoids; smoking status; and current and past use of osteoporosis pharmacological therapies. The study included a total of 8216 patients; 7212 (87.8%) were females, and 1044 (12.2%) were males. In the total population, 13.6% had a Z-score greater than or equal to 2.5 at the lumbar spine, femoral neck, or total hip. Only 0.2% of the males and 0.8% of the females had a Z-score greater than or equal to 2.5 at all 3 sites. The 97.5th percentiles for Z-scores in our population for men and women, respectively, were 3.4 and 3.9 at the lumbar spine, 1.5 and 2.1 at the femoral neck, and 1.6 and 2.2 at the total hip. The 99th percentile for Z-scores for men and women, respectively, were 4.9 and 4.7 at the lumbar spine, 2.4 and 2.7 at the femoral neck, and 2.2 and 2.7 at the total hip. At the lumbar spine, female gender and weight were found to be risk factors for a high Z-score (≥ 2.5). The use of glucocorticoids, bone-active medications, BMI, and smoking were significantly less likely to predict a lumbar spine Z-score greater than or equal to 2.5. A high total-hip Z-score is predicted by increasing weight, whereas those patients using bone-active medications were less likely to have high BMD at the total hip. At the femoral neck, there were no significant risk factors related to a Z-score greater than or equal to 2.5; those taking bone-active medications were significantly less likely to have a high Z-score. These data suggest that a high Z-score is common at 1 or more sites. Further research about the criteria for the diagnosis of high BMD is warranted.

Unplanned surgical excision of extremity soft tissue sarcomas: patient profile and referral patterns.

Unplanned surgical excision of sarcomas remains a major treatment dilemma in the control of local disease. The purpose of this study is to develop a patient profile to identify patients at high risk for an unplanned excision. The study group consisted of 54 patients following an unplanned excision of a soft tissue sarcoma. The characteristics that were identified as high risk included the following: 20- to 40-year age range,>5 cm, trauma, and deep to fascia. It was common for the interpretation of imaging studies not to mention the possibility of sarcoma in the differential diagnosis. Patient referral was most commonly from general surgeons without specialty training in oncology. Orthopaedic surgeons should not rely solely on the radiologist's interpretation because they often lack clinical information necessary to direct them toward the diagnosis of sarcoma. This is particularly important in patients who are at high risk for unplanned excision as identified in this study. Unplanned excisions by nononcologic surgeons remain a problem; however, it appears that it is more prevalent in the general surgical community than in orthopaedics. This may be as a result of studies addressing this issue in orthopaedic journals, with emphasis of these articles at teaching institutions.

A preliminary report on intra-sheath peroneal tendon subluxation: a prospective review of 7 patients with ultrasound verification.

UNLABELLED: Peroneal tendon dislocation with recurrent subluxation over the lateral malleolus, both acute and chronic, is well documented in the literature. However, there remains a subset of patients who report symptoms similar to peroneal subluxation that do not actually display active or passive displacement of the tendon over the lateral malleolus. In this article, we describe 7 patients who were followed prospectively for the treatment of ultrasound-confirmed, retrofibular, intrasheath subluxation without the typical lateral subluxation or dislocation of the tendon over the malleolus. Six of the 7 patients had either a low-lying peroneal muscle belly or a peroneus quartus muscle and tendon, 6 experienced a tear of either 1 or both of the peroneal tendons, and 1 of the 7 had only a peroneus brevis tendon tear without any other muscle anomaly. Repair of concomitant tendon pathology and resection of the low-lying muscle belly to a point proximal to the fibro-osseous tunnel of the retromalleolar space resulted in elimination of the subluxation symptoms and improvement in American College of Foot and Ankle Surgery ankle scores in 3 patients who were treated operatively. LEVEL OF CLINICAL EVIDENCE: 4.

Black hole artifacts-a new potential pitfall for DXA accuracy?

Certain types of metallic objects apparently have high attenuation (a white image) on dual-energy X-ray absorptiometry (DXA) scan images, but instead show up as black (black hole artifacts). When small, these artifacts may easily be missed on visual inspection. We hypothesized that such "black hole" artifacts could have a significant effect on bone mineral density (BMD) results. Human use approval (Institutional Review Board [IRB]) was obtained to publish patient scans and an IRB waiver was obtained for nonhuman research. We placed individual surgical clips and cassettes of clips of tantalum, stainless steel and titanium, and a bullet over the third lumbar vertebra (L3) of a Hologic spine phantom. In addition, 4 or 8 individual tantalum or stainless steel clips and tantalum squares were placed over L3 of cadaveric spines (high-density spine L1-L4 BMD=1.049 g/cm2) and low-density spine BMD (L1-L4 BMD=0.669 g/cm2) with attached soft tissues. Stainless steel and titanium clips scanned as white objects with DXA. A bullet and tantalum clips scanned black (black holes). All clip types were visible on single-energy scans as white objects. Eight tantalum clips significantly lowered L3 BMD compared to 4 or 0 clips in the high-density spine. There were no significant differences in BMD L1-L4 between 0, 4, and 8 tantalum clips in the high-density spine. In the low-density spine, 8 tantalum clips over L3 had significantly lower BMD compared to 4 tantalum clips overlying L3 and 4 clips lateral to L3 and 4 clips over L3. All of these scenarios had lower L3 BMD than no tantalum clips overlying L3. The BMD of L1-L4 was lowest with 8 clips at L3, but was not significantly different than no clips overlying L3. Eight tantalum clips lateral to L3 was significantly higher than no clips over L3. Black hole artifacts can occur in DXA scans containing certain metals like tantalum surgical clips. Although these surgical clips could decrease BMD at a localized area, they do not significantly decrease the L1-L4 spine BMD in a high-density spine specimen. In a low-density spine specimen, tantalum clips do have the potential to alter BMD of a single vertebral body and L1-L4. Attention should be paid to the possibility of black hole artifacts on DXA scans and the effect they may have on spine results. Viewing scans in the single-energy mode can be used to verify the presence of tantalum clips.

The effect of common artifacts lateral to the spine on bone mineral density in the lumbar spine.

Artifacts such as surgical clips, gallstones, and kidney stones are often present in the soft tissue stripe lateral to vertebral bodies. Using cadaveric specimens, we placed bra wires, gallbladder clips, a large gallstone, a calcium carbonate or a calcium citrate pill lateral to L1, or a large or small calcium-containing kidney stone lateral to L3 and compared the mean bone mineral density (BMD) of individual vertebral bodies and L1-L4 with and without the soft tissue artifact. The specimens used had high BMD (L1-L4 BMD=1.049 g/cm2) and low BMD (L1-L4 BMD=0.669 g/cm2) and were scanned with a Hologic Discovery W scanner with 12.7 software in the array mode. None of the artifacts affected L1 or L3 BMD or L1-L4 BMD significantly in the high BMD spine. However, bra wires, a large calcium citrate pill lateral to L1, 3 calcium citrate pills lateral to L1, a calcium carbonate pill over L1, and 3 calcium carbonate pills lateral to L1 did affect L1-L4 BMD in low BMD torso. Gallbladder clips or gallstone did not affect L1-L4 BMD in either specimen. We conclude that artifacts lateral to the spine, particularly in a low BMD spine, can affect the interpretation of L1-L4 BMD using a Hologic Discovery W scanner with 12.7 software in array mode.

Intracranial metastasis from synovial sarcoma.

Synovial sarcomas comprise between 5% to 10% of all soft tissue sarcomas in adults. It has a predilection for young adults and is one of the more frequently misdiagnosed soft tissue sarcomas. It is not unusual for synovial sarcoma to present initially after a traumatic event. It most commonly occurs in close proximity to a large joint. The most common site for metastasis is the lung, followed by lymph node involvement. Synovial sarcoma rarely metastasizes to the skeleton and when it occurs, it most commonly involves the long bones. Cranial metastasis is rare and has only been described in 2 previously reported cases. Reports of other sarcomas having intracranial metastasis include rhabdomyosarcoma, angiosarcoma, fibrosarcoma, liposarcoma, Ewing's sarcoma, and clear cell sarcoma from the kidney. The synchronous or metachronous development of >or=2 primary soft tissue sarcomas has been reported. These are primary soft tissue sarcomas occurring at multiple soft tissue sites without pulmonary or lymphatic involvement. It is often difficult to distinguish between the synchronous or metachronous appearance of a second primary and soft tissue sarcoma metastasis. This article presents a case of a 17-year-old adolescent boy who presented with simultaneous enlarging masses involving the skull and thigh. Open biopsies confirmed synovial sarcoma in both regions. Staging studies, including computed tomography (CT) of his chest, abdomen/pelvis and bone scan were otherwise negative for metastasis.