Radiolucent Implants for Fixation of Impending and Pathologic Fractures.

Radiolucent implants offer theoretical advantages of increased ability to evaluate the fracture site for healing and recurrence and potentially less effect on radiation treatment, avoiding scatter. Their clinical utility and outcomes have yet to be proven in a well-designed randomized trial or large cohort study, although studies based on other indications have shown relative safety and they are approved by the US Food and Drug Administration for treatment of pathologic fractures. Further research is necessary to better understand when and how these implants should be implemented in practice. [Orthopedics. 2022;45(3):e115-e121.].

The radiologist's role in the multidisciplinary team for patients with colon cancer peritoneal metastases.

BACKGROUND: Prevention and treatment of peritoneal metastases from colon cancer is currently under a critical reevaluation. An expanded role of the radiologist in imaging the peritoneum and extrahepatic structures is crucial to progress in this endeavor. METHODS: The critical role of radiology in the evaluation of a primary colon cancer and in diagnosis and assessment of recurrent colon cancer is evaluated. RESULTS: For primary colon cancer the radiologist should forewarn the multidisciplinary team of patients whose malignancy is at high risk for peritoneal metastases and for local recurrence. In recurrent colon cancer a quantitative assessment of the concerning radiologic features are of help to select patients for reoperation. CONCLUSION: An improved primary surgical treatment strategy and more knowledgeable patient selection for reoperation can result from this information.

Early Experience in Pathologic Humerus Fracture Treated With the Photodynamic Bone Stabilization System Shows Limitations Related to Patient Selection.

Impending and complete pathologic fractures often necessitate surgical fixation. Traditional orthopedic implants are commonly used, achieving clinically acceptable outcomes, but their metallic composition can impair radiographic evaluation and affect radiation treatments. Recognition of these concerns led to the development of radiolucent implants such as the minimally invasive Photodynamic Bone Stabilization System (PBSS; IlluminOss Medical Inc), featuring a light cured polymer contained within an inflatable balloon catheter. Two participating hospitals in one health care system reviewed cases using the PBSS implant. Twenty-five patients with 29 impending or pathologic fractures in the proximal radius or humerus from metastatic carcinoma, myeloma, lymphoma, and melanoma were identified. Clinical charts and imaging were reviewed to determine the status of the implant at final follow-up as well as complications. For analysis, a chi-square test was used for nominal variables and a t test was used for continuous variables. Eleven of the 25 patients were alive with disease at the time of analysis. Eight of 29 (27.5%) implants failed. Five of 25 (20%) patients required repeat surgery due to complications, including 3 revision open reduction and internal fixations, 1 open reduction and internal fixation for a periprosthetic fracture, and 1 screw removal. Five of the 9 cases (56%) (P=.03) with lesions in the distal humeral shaft had breakage of the implant by final follow-up, compared with 3 of 20 cases (15%) (P=.03) elsewhere in the humerus; no failures were seen in the radius. One of 4 patients (25%) also had failure in the surgical neck, although this did not reach significance. Five patients were noted to have progression of disease on follow-up radiographs, with 4 failures in patients with progression. The PBSS implants potentially allow improved surveillance of fracture healing and tumor recurrence along with decreased scattering of radiation during treatment. Unfortunately, there may be a higher rate of mechanical failures, particularly for lesions involving the distal humerus. This may be due to decreased cross-sectional area of the implant in this region as compared with the metaphyseal and proximal regions. Caution should be exercised when treating distal humeral pathologic fractures with large lytic lesions where the underlying disease process is not well controlled. [Orthopedics. 2021;44(3):154-159.].

Concerning CT features predict outcome of treatment in patients with malignant peritoneal mesothelioma.

BACKGROUND: Malignant peritoneal mesothelioma is an aggressive local-regional disease with dissemination to all parts of the abdomen and pelvis at the time of diagnosis. Recently, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has been used and improved survival was documented with this local-regional treatment strategy. METHOD: Concerning CT features were described that were specific for malignant peritoneal mesothelioma. The incidence of concerning radiologic features and their impact on survival was determined. The prognostic assessment of concerning CT features was compared to the peritoneal cancer index (PCI) and the completeness of cytoreduction score (CC score). RESULTS: One hundred patients with a preoperative CT were evaluated by 11 concerning CT features. The incidence of these CT features varied between 5% and 41%. Nine of the 11 CT features statistically significantly predicted a reduced survival in these patients treated in a uniform manner. When concerning radiologic features were grouped as none, a single feature or two or more features, a significant composite analysis was achieved with p < 0.001. The prognostic information from concerning CT features compared favorably with the prognostic implications of PCI and CC score. CONCLUSIONS: The availability of the concerning CT features to predict prognosis at the initiation of treatments for malignant peritoneal mesothelioma shows that this radiologic assessment may be of great value to the clinician in planning a treatment strategy for an individual patient.

Lipoblastoma: computed tomographic and magnetic resonance imaging features correlate with tumor behavior and pathology.

BACKGROUND: Lipoblastoma is a rare benign neoplasm of immature fat cells in children. Imaging appearances are frequently complex, sometimes simulating liposarcoma. OBJECTIVE: To characterize features of lipoblastoma on MRI and CT in comparison with recurrence risk. MATERIALS AND METHODS: We identified cases via retrospective review of histopathology-proven lipoblastoma cases in a large referral database and a pediatric medical center. Two radiologists scored CT and MRI on the basis of lesion features. RESULTS: We included a total of 56 children (32 boys and 24 girls) with a mean age of 2.6 years (range 0.1-13 years). Extremity lesions were most common (27%), followed by neck (19%), gluteal region (18%), chest (14%) and mesentery (14%). Children most commonly presented with painless masses (73%), followed by dyspnea (9%), distension (9%) and pain (7%). Non-adipose soft-tissue components were identified on CT and MRI in 78% of cases. Significant (moderate or marked) septations were noted in 59% and enhancement in 35%. Compartmental invasion was present in 43% of cases. Of paraspinal cases, 38% involved the neural foramina or central canal. Lesion complexity did not significantly correlate with age. Recurrence was observed in 9% of cases and was significantly correlated with compartmental invasion (correlation: 0.303, P=0.009) and septation complexity (correlation: 0.227, P=0.038) on initial imaging. CONCLUSION: Although lipoblastoma is a fat-containing entity, many lesions demonstrate marked complexity and local infiltration that resemble liposarcoma, which is exceedingly rare in younger children. Compartmental invasion and thicker septations appear to confer greater risk of recurrence following resection.

Unusual radiologic presentations of malignant peritoneal mesothelioma.

BACKGROUND: Malignant peritoneal mesothelioma is an unusual disease process characterized radiologically by ascites and infiltration of the peritoneum by multiple small tumor nodules. Both parietal and visceral peritoneum are involved by the multiple malignant tumor nodules. Computed tomography (CT) has been used to identify the anatomic pathology induced by the progression of this malignant process. AIM: To identify and then describe unusual CT images in patients with malignant peritoneal mesothelioma. Recognition of these unusual radiologic findings can cause the radiologist to be suspicious of this rare malignant process. METHODS: In 100 patients who were to undergo definitive treatment of malignant peritoneal mesothelioma, the findings on preoperative CT scans were catalogued. Many of these changes were repeatedly noted on the CT scans. Other pathologic CT images were less common. These unusual radiologic presentations were specially studied in this manuscript. RESULTS: Eight unusual radiologic presentations of malignant peritoneal mesothelioma were selected for study. These unusual findings included a mass occurring within a Spigelian hernia, infiltration of the splenic parenchyma by spherical mesothelioma masses, infiltration of the lower mediastinum by tumor, a mesothelioma mass within a left inguinal canal, enlarged cardiophrenic angle lymph nodes, pleural plaques associated with the progression of malignant peritoneal mesothelioma, splenic notches caused by disease surrounding the spleen, and a mass greater than 5 cm associated with the proximal jejunum and directly adjacent to the anatomic location of the Treitz ligament. CONCLUSION: There are unusual radiologic presentations of malignant peritoneal mesothelioma that are important to recognize in order to accurately diagnose this disease by CT.

Gouty involvement of the patella and extensor mechanism of the knee mimicking aggressive neoplasm. A case series.

Gout is a common inflammatory crystal deposition disease that occurs in many joints throughout the body. Active gout is most often associated with painful synovitis causing searing joint pains, but gout can also produce large masses of space-occupying deposits called tophi. Tophi are most frequently seen in juxta-articular locations with or without bony erosion and are often misdiagnosed as degenerative joint disease. Soft tissue deposits and tendon involvement are also known manifestations of gout, but can present with indeterminate and alarming findings on imaging. We present three cases of tophaceous gout mimicking aggressive neoplasms in the extensor mechanism of the knee. All cases presented as extensor tendon masses eroding into the patella, with imaging findings initially concerning for primary musculoskeletal malignancy.

Concerning CT features used to select patients for treatment of peritoneal metastases, a pictoral essay.

BACKGROUND: During the Fifth International Workshop on Peritoneal Surface Malignancy in Milan in 2008, a consensus was reached that contrast-enhanced CT (ceCT) was the principal imaging modality for patients being evaluated for treatment of peritoneal metastases. This fact being accepted, the radiologic criteria for that may exclude patients from a high value cytoreductive surgery (CRS) plus hyperthermic perioperative chemotherapy (HIPEC) have not been reliably determined. METHODS: From a consensus of surgeons and radiologists, radiologic images were selected and their determinant radiologic characteristics described. The anatomic pathology causing the abnormal images were identified and characterised. The cytoreductive surgical procedures that may, in selected patients, result in a complete resection of the pathology identified were presented. RESULTS: Radiographs of 15 CT images that cause concern when a patient is being evaluated for CRS were listed. The anatomic pathology these images define and possible surgical resections they require were reviewed. The surgical implications of the absence or presence of a single, or of multiple concerning CT features was extracted from the surgical and radiologic literature. CONCLUSIONS: There is a definite need to identify new pre-operative imaging parameters to define optimal indication of CRS with HIPEC. The presence of a single concerning radiologic feature is associated with the possibility of an adverse outcome or technically more complex resections associated with increased morbidity and mortality. If two or more of the concerning radiologic features are described from the CT, suboptimal cytoreduction will usually occur.

Quadriparesis Caused by Lead Poisoning Nine Years After a Gunshot Wound With Retained Bullet Fragments: A Case Report.

Lead toxicity in adults is characterized by nonspecific symptoms of abdominal pain, vomiting, constipation, fatigue, and weight loss. We present a case of severe lead toxicity that developed subacutely, causing quadriparesis 9 years after a gunshot wound with retained bullet fragments. The onset of symptoms may have been related to the development of a pseudocyst. The long interval between the gunshot wound and the onset of symptoms contributed to a delay in suspecting that the retained bullet was a source of lead toxicity. The patient's symptoms gradually improved after chelation therapy, removal of the bullet fragment, and an extended program of acute inpatient rehabilitation. LEVEL OF EVIDENCE: V.

Phase 2 clinical trial of sunitinib as adjunctive treatment in patients with advanced differentiated thyroid cancer.

OBJECTIVE: Our objective was to evaluate the efficacy and safety of sunitinib following at least one course of radioactive iodine treatment in patients with advanced differentiated thyroid cancer (DTC). The study endpoints included best response rate (including best objective response rate) and progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, measurement of serum thyroglobulin (Tg), and toxicity evaluation. DESIGN AND METHODS: This was a single center, nonrandomized, open-label, phase 2 clinical trial. In total, 23 patients were enrolled and were treated with a starting daily, oral dose of 37.5  mg sunitinib. Patients were evaluated with imaging, laboratory tests, and physical examination periodically per protocol. RESULTS: The mean best response was a decrease of 17.2% (S.D. 22.8) in tumor sum from baseline. Six (26%) patients achieved a partial response (PR), and 13 (57%) had stable disease (SD) for a clinical benefit rate (PR+SD) of 83%. The overall median PFS was 241 days (interquartile limits, 114-518). No statistically significant difference was observed between the medians of the baseline and post-treatment Tg values (P=0.24). The most common adverse events included grades 1 and 2 decreases in blood cell counts (especially leukocytes), diarrhea, fatigue, hand-foot skin reaction, nausea, musculoskeletal pain, and hypertension. CONCLUSIONS: These data demonstrate that sunitinib exhibits significant anti-tumor activity in patients with advanced DTC. Since sunitinib was relatively well-tolerated, there is the potential for clinical benefit in these patients, and further investigation of this agent is warranted.

Radiation exposure from diagnostic procedures following allogeneic stem cell transplantation--how much is acceptable?

BACKGROUND: Frequent diagnostic radiology procedures in allogeneic stem cell transplantation (SCT) recipients raise concern about the potential harm from incidental radiation. OBJECTIVES: To determine the cumulative radiation dose from diagnostic studies in allogeneic SCT and its impact on clinical outcome. PATIENTS AND METHODS: This retrospective cohort study was conducted to determine the cumulative radiation dose from diagnostic studies following SCT. Sixty-four consecutive patients with hematological malignancies in a single tertiary care institution underwent total body irradiation (TBI)-based myeloablative conditioning followed by six of six human leukocyte antigen (HLA)-identical sibling allogeneic SCT. The median follow-up was 3 years. The cumulative effective dose in mSv from diagnostic radiological studies in the peri-transplant period from day -30 to day +200 was calculated for each patient and its impact on overall survival and non-relapse mortality was determined. RESULTS: The median cumulative radiation exposure from diagnostic radiological procedures was 92 mSv (range 1.2-300), representing about 30× the normal annual background radiation for the population and 10% of the 1200 cGy TBI dose used in conditioning. Sixty-five percent of the cumulative radiation exposure was delivered between day +1 and day 100 and computed tomography scans contributed 88%. In multivariate analysis, diagnostic procedures did not significantly impact clinical outcomes. CONCLUSIONS: While radiation exposure from diagnostic procedures did not impact clinical outcomes the risk of secondary cancers in long-term survivors is likely to be increased. Our results indicate that patients who are acutely ill for prolonged periods can receive clinically significant radiation doses during their hospital care. Our findings should prompt attempts to limit radiation exposure from diagnostic procedures in post-SCT recipients.

Current imaging and therapy of malignant soft tissue tumors and tumor-like lesions.

Soft tissue tumors are histologically classified based on the tissue type they reflect. MR and computed tomography imaging remains the mainstay for the evaluation of a soft tissue mass including guiding the biopsy to the most aggressive portion of the lesion, tumor staging, and evaluating local recurrence and metastatic disease. Although some lesions may be readily identified based on their imaging characteristics, many soft tissue tumors remain indeterminate and require biopsy for diagnosis of histologic type and lesion grade, factors that have an impact on therapeutic options and long-term disease-free survival.In this article we review the current literature regarding imaging and treatment of soft tissue lesions in the musculoskeletal system. Positron emission tomography and specialized MR techniques, such as spectroscopy and diffusion-weighted imaging, are useful in the diagnosis of high-grade soft tissue sarcomas, although imaging overlap exists with benign and low-grade sarcomas. These modalities are proving useful in primary tumor staging, evaluation of therapeutic response, and metastatic disease assessment. We also discuss the roles of percutaneous ablation in the treatment of focal disease and palliative pain control, and review current targeted cancer therapies.

Correlates of axial gout: a cross-sectional study.

OBJECTIVE: A cross-sectional study was undertaken to determine the prevalence of axial gout in patients with established gouty arthritis and to analyze clinical, laboratory, and radiological correlations. METHODS: Forty-eight subjects with a history of gouty arthritis (American College of Rheumatology criteria) for ≥ 3 years under poor control were included. Subjects underwent history, physical examination, laboratory testing, and imaging studies, including radiographs of the hands and feet and computerized tomography (CT) of the cervical and lumbar spines and sacroiliac joints (SIJ). Patients with characteristic erosions and/or tophi in the spine or SIJ were considered to have axial or spinal gout. RESULTS: Seventeen patients (35%) had CT evidence of spinal erosions and/or tophi, with tophi identified in 7 of the 48 subjects (15%). The spinal location of axial gout was cervical in 7 patients (15%), lumbar in 16 (94%), SIJ in 1 (6%), and more than 1 location in 14 (82%). Duration of gout, presence of back pain, and serum uric acid levels did not correlate with axial gout. Extremity radiographs characteristic of gouty arthropathy found in 21 patients (45%) were strongly correlated with CT evidence of axial gout (p < 0.001). All patients with tophi in the spine had abnormal hand or feet radiographs (p = 0.005). CONCLUSION: Axial gout may be a common feature of chronic gouty arthritis. The lack of correlation with back pain, the infrequent use of CT imaging in patients with back pain, and the lack of recognition of the problem of spinal involvement in gouty arthritis suggest that this diagnosis is often missed.

Bilateral synchronous tibial periosteal osteosarcoma with familial incidence.

Multifocal or multicentric osteosarcoma (OS) has been described as tumor occurrence at two or more sites in a patient without visceral metastasis. These may be synchronous (more than one lesion at presentation) or metachronous (new tumor developing after the initial treatment). The incidence of multifocal OS has ranged from 1.5 to 5.4% in large series, with the synchronous type being rarer. Similarly, periosteal OS is another rare subtype of surface OS and constitutes less than 2% of all OS. An 11-year-old female was diagnosed with bilateral synchronous tibial periosteal OS, which were confirmed by CT-guided biopsies. After neoadjuvant chemotherapy, the patient underwent a staged wide local resection of the tumors. The defect was reconstructed with a proximal tibial replacement on the left side and autologous bone grafting on the right side. The patient did well after surgery and is free of disease at 5.5 years of follow-up. However, her brother also developed a right tibial periosteal osteosarcoma 4 years after her index surgery. Genetic analysis of blood sample from both patients showed a similar missense mutation in at least one allele of TP53 gene (exon 8). To the best of our knowledge, a case of bilateral 'synchronous' periosteal OS with a familial incidence has not been reported before.

Aseptic loosening rates in distal femoral endoprostheses: does stem size matter?

BACKGROUND: Long-term survival of distal femoral endoprosthetic replacements is largely affected by aseptic loosening. It is unclear whether and to what degree surgical technique and component selection influence the risk of loosening. QUESTIONS/PURPOSES: We (1) established the overall failure and aseptic loosening rates in a tumor population and asked (2) whether stem diameter and specifically the diaphysis-to-stem ratio predicts loosening, and (3) whether resection percentage correlates with failure. METHODS: We retrospectively reviewed the charts of all 93 patients in whom 104 distal femoral replacements had been performed from 1985 to 2008. We extracted the following data: age, need for revision surgeries, tumor diagnosis, adjunct treatment, and implant characteristics. We reviewed radiographs and determined stem size, bone diaphyseal width, and resection percentage of the femur. Kaplan-Meier survivorship was calculated for all implant failures and failures resulting from aseptic loosening. We evaluated radiolucent lines in patients with radiographic followup over 5 years. We identified independent risk factors for loosening. The minimum followup for radiographic evaluation was 5 years (mean, 12.7 years; range, 5.4-23.5 years). RESULTS: Overall implant survival for 104 stems in 93 patients was 73.3% at 10 years, 62.8% at 15 years, and 46.1% at 20 years. Survival from aseptic loosening was 94.6% at 10 and 15 years and 86.5% at 20 years. Of the variables analyzed, only bone:stem ratio independently predicted aseptic failure. Patients with stable implants had larger stem sizes and lower bone:stem ratios than those with loose implants (14.5 mm versus 10.7 mm and 2.02 versus 2.81, respectively). CONCLUSIONS: Our data suggest durability relates to selecting stems that fill the canal. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Metaphyseal and diaphyseal chondroblastomas.

OBJECTIVE: Epiphyseal/apophyseal locations are important diagnostic radiological features of chondroblastomas (CB). Although the tumor may secondarily involve the metaphysis, reports of primary metaphyseal or diaphyseal CB without any epiphyseal or apophyseal involvement are exceptionally rare and frequently present as a diagnostic dilemma. The purpose of this study was to present seven cases of pure metaphyseal and/or diaphyseal CB along with a review of pertinent literature. METHODS: A retrospective review of databases at two major referral centers revealed 390 cases of CB between 1960 and 2009. Out of these, seven histologically proven CB cases (1.8%) were found to be radiologically located in metaphysis and/or diaphysis, without involving the epiphysis and/or apophysis, and formed the study cohort. RESULTS: There were four males and three females (age range 2-25 years). Locations included proximal femur (n = 1), distal femur (2), proximal humerus (2), clavicle (1), and proximal radius (1). All lesions showed marginal sclerosis. A periosteal reaction was seen in five cases (71%), cortical expansion in four cases (57%), and chondroid matrix in four cases (57%). A CT (two cases) demonstrated a matrix in both cases. An MR (one case) showed extensive perilesional edema. Bone scan (one case) showed intense uptake. CONCLUSION: Pure metaphyseal and/or diaphyseal CB are exceedingly rare. A presumptive diagnosis may be considered in the appropriate age group in the presence of chondroid matrix, perilesional edema, periosteal reaction, and marginal sclerosis. Regardless of all the diagnostic possibilities, biopsy may still be required. However, knowledge of this entity will help make the final diagnosis and guide the correct treatment.

Gout in the axial skeleton.

OBJECTIVE: Gout typically affects the peripheral joints of the appendicular skeleton and rarely involves the axial joints. The literature on axial gout is limited to case reports and case series. This preliminary study was conducted to identify the frequency and characteristics of axial gout. METHODS: Six hundred thirty medical records with ICD codes 274.0, 274.82, and 274.9 for peripheral gout were reviewed. Ninety-two patients had clinical or crystal-proven gout, of which 64 had prior computed tomography (CT) images of the spine performed for various medical reasons. These CT images were reviewed for features of axial gout, which include vertebral erosions mainly at the discovertebral junction and the facet joints, deposits of tophi, and erosions in the vertebral body, epidural space, ligamentum flavum and pars interarticularis. RESULTS: Nine of the 64 patients had radiographic changes suggestive of axial gout. Lumbar vertebrae were most commonly involved, with facet joint erosions being the most common finding. Isolated involvement of the sacroiliac joints was seen in 2 patients. Axial gout had been diagnosed clinically in only one patient. CONCLUSION: Radiologic changes of axial gout were more common than recognized clinically, with a frequency of 14%. Since not all patients had CT images, it is possible that the frequency of axial involvement was even greater. A prospective study is needed to further define this process.