Bone Mass Changes Following Percutaneous Radiofrequency Ablation, Osteoplasty, Reinforcement, and Internal Fixation of Periacetabular Osteolytic Metastases.

BACKGROUND: The success of orthopedic interventions for periacetabular osteolytic metastases depends on the progression or regression of cancer-induced bone loss. PURPOSE: To characterize relative bone mass changes following percutaneous radiofrequency ablation, osteoplasty, cement reinforcement, and internal screw fixation (AORIF). METHODS: Of 70 patients who underwent AORIF at a single institution, 21 patients (22 periacetabular sites; average follow-up of 18.5 ± 12.3 months) had high-resolution pelvic bone CT scans, with at least one scan within 3 months following their operation (baseline) and a comparative scan at least 6 months post-operatively. In total, 73 CT scans were measured for bone mass changes using Hounsfield Units (HU). A region of interest was defined for the periacetabular area in the coronal, axial, and sagittal reformation planes for all CT scans. For 6-month and 1-year scans, the coronal and sagittal HU were combined to create a weight-bearing HU (wbHU). Three-dimensional volumetric analysis was performed on the baseline and longest available CT scans. Cohort survival was compared to predicted PathFx 3.0 survival. RESULTS: HU increased from baseline post-operative (1.2 ± 1.1 months) to most recent follow-up (20.2 ± 12.1 months) on coronal (124.0 ± 112.3), axial (140.3 ± 153.0), and sagittal (151.9 ± 162.4), p < 0.05. Grayscale volumetric measurements increased by 173.4 ± 166.4 (p < 0.05). AORIF median survival was 27.7 months (6.0 months PathFx3.0 predicted; p < 0.05). At 12 months, patients with >10% increase in wbHU demonstrated superior median survival of 36.5 months (vs. 26.4 months, p < 0.05). CONCLUSION: Percutaneous stabilization leads to improvements in bone mass and may allow for delays in extensive open reconstruction procedures.

Percutaneous Ablation, Osteoplasty, Reinforcement, and Internal Fixation for Pain and Ambulatory Function in Periacetabular Osteolytic Malignancies.

Background Osteolytic neoplasms to periacetabular bone frequently cause pain and fractures. Immediate recovery is integral to lifesaving ambulatory oncologic care and maintaining quality of life. Yet, open acetabular reconstructive surgeries are associated with numerous complications that delay cancer treatments. Purpose To determine the effectiveness for short- and long-term pain and ambulatory function following percutaneous ablation, osteoplasty, reinforcement, and internal fixation (AORIF) for periacetabular osteolytic neoplasm. Materials and Methods This retrospective observational study evaluated clinical data from 50 patients (mean age, 65 years ± 14 [SD]; 25 men, 25 women) with osteolytic periacetabular metastases or myeloma. The primary outcome of combined pain and ambulatory function index score (range, 1 [bedbound] through 10 [normal ambulation]) was assessed before and after AORIF at 2 weeks and then every 3 months up to 40 months (overall median follow-up, 11 months [IQR, 4-14 months]). Secondary outcomes included Eastern Cooperative Oncology Group (ECOG) score, infection, transfusion, 30-day readmission, mortality, and conversion hip arthroplasty. Serial radiographs and CT images were obtained to assess the hip joint integrity. The paired t test or Wilcoxon signed-rank test and Kaplan-Meier analysis were used to analyze data. Results Mean combined pain and ambulatory function index scores improved from 4.5 ± 2.4 to 7.8 ± 2.1 (P < .001) and median ECOG scores from 3 (IQR, 2-4) to 1 (IQR, 1-2) (P < .001) at the first 2 weeks after AORIF. Of 22 nonambulatory patients, 19 became ambulatory on their first post-AORIF visit. Pain and functional improvement were retained beyond 1 year, up to 40 months after AORIF in surviving patients. No hardware failures, surgical site infections, readmissions, or delays in care were identified following AORIF. Of 12 patients with protrusio acetabuli, one patient required a conversion hemiarthroplasty at 24 months. Conclusion The ablation, osteoplasty, reinforcement, and internal fixation, or AORIF, technique was effective for short- and long-term improvement of pain and ambulatory function in patients with periacetabular osteolytic neoplasm. © RSNA, 2023.

Rare Presentation of Rosai-Dorfman Disease in Soft Tissue: Diagnostic Findings and Surgical Treatment.

Introduction and Importance. Rosai-Dorfman disease (RDD) is a rare, benign type II histiocytosis characterized by the infiltration of S100+ histiocytes and emperipolesis. The disease may present in the lymph nodes (nodal RDD), in extranodal sites, or in both nodal and extranodal sites. Among those patients who present exclusively in extranodal sites, only a minority of cases present in the soft tissue. Case Presentation. An 18-year-old female presented to orthopedic oncology clinic with a chief complaint of a mass located in her lower back. The patient underwent excision of the lumbosacral mass. Pathologic review demonstrated emperipolesis of lymphocytes and plasma cells within enlarged, eosinophilic histiocytes in a background of lymphoplasmacytic infiltration and collagenous stroma. Immunohistochemical staining demonstrated S100+ and CD163+ histiocytes, consistent with diagnosis of soft tissue RDD. Clinical Discussion. Histologically, RDD is generally characterized by emperipolesis-the presence of intact lymphocytes within the histiocyte cytoplasm-and a mixed infiltrate of S100+ histiocytes, mononuclear cells, plasma cells, and lymphocytes. Although soft tissue RDD may histologically resemble nodal RDD, soft tissue RDD also demonstrates some notable histologic differences including the lack of nodal architecture, the presence of increased fibrosis and collagen deposition, and generally fewer RDD cells. Conclusion. This case presentation demonstrates one few reports of isolated soft tissue RDD within the lumbosacral region without associated lymphadenopathy or skin changes and highlights the heterogeneity that still exists in the treatment paradigm of extranodal RDD.

Bone Scans Have Little Utility in the Evaluation of Well-Differentiated Cartilaginous Lesions of the Humerus.

In the humerus, pain is a poor guide for differentiating between benign enchondromas and malignant well-differentiated chondrosarcomas. Radionuclide bone scans often are used, and chondrosarcomas reliably show increased uptake. However, it remains to be seen whether enchondromas consistently have negative findings on bone scans, which would provide reliable differentiation from malignant lesions. Imaging and medical records were reviewed for patients who underwent radionuclide bone scans for enchondroma of the humerus at one academic medical center over a period of 7 years. Bivariate logistic regression was used to determine the association of bone scan results with the finding of endosteal scalloping on radiographs and magnetic resonance imaging (MRI) scans. During initial evaluation, 25 patients who had enchondroma of the humerus underwent radionuclide bone scans. No patients showed progression of lesions during an average follow-up of 69 weeks. On bone scan, 18 (72%) had significantly positive findings, 5 (20%) had mildly positive findings, and 2 (8%) had negative findings. Of the 22 patients who underwent MRI scans, 4 showed endosteal scalloping and none showed aggressive features. No statistically significant association was seen between significantly positive (P=.299) or mildly positive findings on bone scans (P=.810) and the finding of endosteal scalloping on radiographs or MRI scans. Enchondromas rarely showed negative findings on bone scans, and bone scan findings did not correlate with the findings on radiographs or MRI scans. The diagnosis of enchondroma can be made based on clinical and radiographic findings, and the added utility of bone scans does not justify their regular use. [Orthopedics. 2020;43(6):e498-e502.].

Synovial Myxoma: Found in Canines, Rabbits, and Now Humans Too?: A Case Report.

CASE: A 63 year-old woman presented with a multiple-year history of right knee pain and effusions and pain refractory to numerous knee aspirations and an arthroscopic synovectomy. The patient underwent a 2-incision synovectomy and intralesional resection. A pathologic review of the specimens revealed an infiltrative tumor of basophilic, cluster of differentiation 68-positive synovial cells embedded within a myxoid stroma with low proliferative activity, most consistent with a synovial myxoma. CONCLUSIONS: This case report of a synovial myxoma-a benign, slow growing but locally aggressive mass that is most commonly found in canines-indicates that the lesion may occasionally occur in humans.

Predictors of Lymph Node Involvement by Soft Tissue Sarcoma of the Trunk and Extremity: An Analysis of the National Cancer Database.

Background and Objectives Lymph node metastases (LNM) in soft tissue sarcoma (STS) of the trunk and extremity are rare but are associated with worse survival. Established risk factors for LNM in this group are based on small institutional retrospective reviews. This study identifies the risk factors associated with LNM in otherwise non-metastatic trunk/extremity STS patients using the National Cancer Database (NCDB) and sought out to delineate a high-risk group that may be considered for pathologic nodal evaluation. Methods The files of 10,731 patients with STS of the trunk/extremity without distant metastasis from 2004 - 2015 were evaluated. Exclusion criteria included neoadjuvant therapy and a lack of pathologic nodal evaluation. Univariate and multivariable logistic regression models were performed to evaluate variables associated with LNM. Results Of the total of 10,731 patients, 223 (2.1%) had LNM. On multivariable analysis, LNM was associated with Grade 3 tumors (odds ratio (OR) 15.6, 95% confidence interval (CI) 6.36 - 38.04, p < 0.001) and clear cell/angiosarcoma/rhabdomyosarcoma/epithelioid (CARE) histology (OR 4.72, 95% CI 3.35 - 6.66, p < 0.001), lymphovascular invasion (LVI) (OR 5.86, 95% CI 3.33 - 10.31, p < 0.001, and bone invasion (BI) (OR 2.73, 95% CI 1.32 - 5.61, p = 0.006). Patients with Grade 3 CARE tumors (n = 402) had an 11.9% risk of LNM vs. 1.7% of adults without all these characteristics (p < 0.001). Patients with Grade 3 CARE tumors and either LVI or BI (n = 36) had a 33.3% risk of LNM. Conclusions High-grade and CARE histology are associated with LNM in STS. Adult patients with both features have an overall 11.9% risk of LNM and may be considered for pathologic LN assessment, particularly with the presence of LVI or BI.

Bone Marrow Adiposity: Basic and Clinical Implications.

The presence of adipocytes in mammalian bone marrow (BM) has been recognized histologically for decades, yet, until recently, these cells have received little attention from the research community. Advancements in mouse transgenics and imaging methods, particularly in the last 10 years, have permitted more detailed examinations of marrow adipocytes than ever before and yielded data that show these cells are critical regulators of the BM microenvironment and whole-body metabolism. Indeed, marrow adipocytes are anatomically and functionally separate from brown, beige, and classic white adipocytes. Thus, areas of BM space populated by adipocytes can be considered distinct fat depots and are collectively referred to as marrow adipose tissue (MAT) in this review. In the proceeding text, we focus on the developmental origin and physiologic functions of MAT. We also discuss the signals that cause the accumulation and loss of marrow adipocytes and the ability of these cells to regulate other cell lineages in the BM. Last, we consider roles for MAT in human physiology and disease.

Femoral and Tibial Reconstruction for Skeletal Metastases and Pathologic Fractures.

Skeletal metastases of the femur and tibia leading to pathologic fractures or large skeletal defects can be managed with surgical reconstruction, resulting in improved patient outcomes and functionality. The indications for femoral and tibial reconstruction are dependent on several factors, including goals of management, age, comorbidities, site and extent of the lesion, soft-tissue involvement, and history of radiation or other systemic therapy. The goal of reconstruction of large bone defects is to restore anatomy and function while minimizing the risk of complications, implant failure, and subsequent revision procedure. Common reconstructive options include fixation with plates and screws, intramedullary nails, and endoprosthesis implantation.

What Is the Adverse Event Profile After Prophylactic Treatment of Femoral Shaft or Distal Femur Metastases?

BACKGROUND: Prophylactic surgical treatment of the femur is commonly offered to patients with metastatic disease who have a high risk of impending pathologic fracture. Prophylactic fixation is associated with improved functional outcomes in appropriate patients selected based on established criteria, but the perioperative complication profile has received little attention. Given the substantial comorbidity in this population, it is important to characterize surgical risks for surgeons and patients to improve treatment decisions. QUESTIONS/PURPOSES: (1) What is the incidence of postoperative adverse events after prophylactic surgical stabilization of metastatic lesions of the femoral shaft or distal femur? (2) How does this complication profile compare with stabilization of pathologic fractures adjusted for differences in patient demographics and comorbidity? METHODS: We performed a retrospective study using the National Surgical Quality Improvement Program (NSQIP) database. We identified patients undergoing prophylactic treatment of the femoral shaft or distal femur by Current Procedural Terminology (CPT) codes. Patients undergoing treatment of a pathologic fracture were identified by CPT code for femur fracture fixation as well as an International Classification of Diseases code indicating neoplasm or pathologic fracture. We tracked adverse events, operative time, blood transfusion, hospital length of stay, and discharge to a facility within 30 days postoperatively. There were 332 patients included in the prophylactic treatment group and 288 patients in the pathologic fracture group. Patients in the prophylactic treatment group presented with greater body mass index (BMI), whereas the pathologic fracture group presented with a greater incidence of disseminated cancer. The odds of experiencing adverse events were initially compared between the two groups using bivariate logistic regression and then using multivariate regression controlling for age, sex, BMI, and American Society of Anesthesiologists (ASA) class and disseminated cancer causing marked physiological compromise per NSQIP guidelines. RESULTS: With multivariate analysis controlling for age, sex, BMI, and ASA class, patients with pathologic fracture were more likely to experience any adverse event (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.03-2.29; p = 0.036), major adverse events (OR, 1.61; 95% CI, 1.01-2.55; p = 0.043), death (OR, 1.90; 95% CI, 1.07-3.38; p = 0.030), blood transfusion (OR, 1.57; 95% CI, 1.08-2.27; p = 0.017), and hospital stay ≥ 9 days (OR, 1.51; 95% CI, 1.05-2.19; p = 0.028) compared with patients undergoing prophylactic treatment. However, when additionally controlling for disseminated cancer, the only difference was that patients with pathologic fractures were more likely to receive a blood transfusion than were patients undergoing prophylactic fixation (OR, 1.61; 95% CI, 1.12-2.36; p = 0.011). CONCLUSIONS: After controlling for differences in patient characteristics, prophylactic treatment of femoral metastases was associated with a decreased likelihood of blood transfusion and no differences in terms of the frequency of other adverse events. In the context of prior studies supporting the mechanical and functional outcomes of prophylactic treatment, the findings of this cohort suggest that the current guidelines have achieved a reasonable balance of morbidity in patients with femoral lesions and further support the current role of prophylactic treatment of impending femur fractures in appropriately selected patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

Leiomyoma of the Foot and Ankle: A Case Series.

Leiomyoma is a benign soft-tissue tumor that can arise in any soft tissue; however, in the extremities, it is usually a subcutaneous mass. Masses in the foot and ankle in general are rare, and few reports in the literature describe leiomyoma in this region of the body. We present a series of 8 cases of leiomyoma of the foot and ankle, 4 of which are subclassified as angioleiomyomas. The characteristic patient presentation, imaging, and histological findings are presented here to increase awareness of this soft-tissue mass in the foot and ankle. LEVELS OF EVIDENCE: Level V.

Bilateral atypical femur fractures without bisphosphonate exposure.

Atypical femur fractures have common radiographic features that set them apart from more typical higher-energy subtrochanteric femur fractures. They are noncomminuted, transverse fractures with medial spiking of the femoral cortex and increased lateral cortical thickness. These fractures have been associated in the literature with the use of bisphosphonate medications. This case describes bilateral atypical femur fractures in a patient with a medical history devoid of bisphosphonate use. We present his history, co-morbidities, and subsequent treatment. From this case, we call attention to bisphosphonate use as not the only cause of subtrochanteric femur fractures with atypical features and highlight that some patients may sustain these injuries even bilaterally without use of the medications. In addition, it is important to identify this fracture type and obtain imaging of the contralateral femur to facilitate prophylactic treatment if needed.

Case of a Missed Giant Cell Tumor of Bone: An Opportunity to Observe its Natural History Disease.

Giant cell tumor of bone (GCT) is a benign neoplasm that most commonly presents with pain and is rarely diagnosed as an incidental finding. We present the report of a young woman whose pre-operative MRI was only noted to have a tear of the anterior cruciate ligament (ACL). Subsequently, the patient underwent anACL reconstruction. A second MRI, performed four years later, demonstrated an enlarged mass in the same location. A retrospective evaluation of the initial MRI revealed an eccentric metaphyseal lesion. Histology obtained from the lesion demonstrated a giant cell tumor of bone. We present the case of an asymptomatic GCT discovered retrospectively as an incidental finding and reevaluated four years later. 'Ihis case serves as a reminder of the importance for the critical review of routine preoperative imaging and also offers a unique perspective on the natural history of giant cell tumor of bone.

Intraoperative radiofrequency ablation for osteoid osteoma.

Percutaneous radiofrequency ablation (RFA) has been increasingly used in the treatment of osteoid osteoma (OO), as this method has provided satisfactory results with minimal morbidity. RFA traditionally has been performed by radiologists under computed tomography (CT) guidance. Advances in intraoperative imaging techniques now allow orthopedic oncologists to perform image-guided RFA in the operating room. We conducted a study to evaluate the efficacy of a novel technique that uses intraoperative CT-guided RFA to treat OO. We reviewed 28 consecutive cases of OO treated with intraoperative RFA by a single surgeon between September 2004 and December 2008. Primary or secondary success was defined as complete pain relief without evidence of recurrence after the first or second procedure, respectively. Failure was defined as the continued presence of symptoms combined with radiographic evidence of recurrence. Primary success rate was 92.8%. Two patients had a recurrence and underwent a successful second RFA. Our success rates are similar to those in the radiology literature. Further studies are needed to validate the efficacy of this novel technique.

Genetic alterations in chondrosarcomas - keys to targeted therapies?

BACKGROUND: Chondrosarcomas are malignant tumors of chondrocytes and represent the second most common type of primary bone tumors. Within the context of normal chondrogenesis, this review summarizes results from recent research outlining the key molecular changes that occur during the development of this sarcoma type. RESULTS: Current data support the notion that a two-hit scenario, common to many tumors, also underlies chondrosarcoma formation. First, early-stage mutations alter the normal proliferation and differentiation of chondrocytes, thereby predisposing them to malignant transformation. These early-stage mutations, found in both benign cartilaginous lesions and chondrosarcomas, include alterations affecting the IHH/PTHrP and IDH1/IDH2 pathways. As they are not observed in malignant cells, mutations in the EXT1 and EXT2 genes are considered early-stage events providing an environment that alters IHH/PTHrP signaling, thereby inducing mutations in adjacent cells. Due to normal cell cycle control that remains active, a low rate of malignant transformation is seen in benign cartilaginous lesions with early-stage mutations. In contrast, late-stage mutations, seen in most malignant chondrosarcomas, appear to induce malignant transformation as they are not found in benign cartilaginous lesions. These late-stage mutations primarily involve cell cycle pathway regulators including p53 and pRB, two genes that are also known to be implicated in numerous other human tumor types. CONCLUSIONS: Now the key genetic alterations involved in both early and late stages of chondrosarcoma development have been identified, focus should be shifted to the identification of druggable molecular targets for the design of novel chondrosarcoma-specific therapies.

Orthopaedic management improves the rate of early osteoporosis treatment after hip fracture. A randomized clinical trial.

BACKGROUND: Although osteoporosis is strongly associated with hip fractures, the initiation of osteoporosis treatment following hip fractures occurs at surprisingly low rates of between 5% and 30%. Currently, most patients receiving treatment have been referred back to their primary care physician for osteoporosis management. The purpose of this study was to compare the effect of osteoporosis management initiated by the orthopaedic team and osteoporosis management initiated by the primary care physician on the rates of treatment at six months. METHODS: A prospective randomized trial was conducted to assess the difference in the rate of osteoporosis treatment when an in-house assessment of osteoporosis was initiated by the orthopaedic surgeon and follow-up was conducted in a specialized orthopaedic osteoporosis clinic compared with osteoporosis education and "usual" care. RESULTS: Sixty-two patients were enrolled in the study. Thirty-one patients each were in the control and intervention groups. The percentage of patients who were on pharmacologic treatment for osteoporosis at six months after the fracture was significantly greater when the evaluation was initiated by the orthopaedic surgeon and was managed in a specialized orthopaedic osteoporosis clinic (58%) than when treatment was managed by a primary care physician (29%) (p = 0.04). CONCLUSIONS: An active role by orthopaedic surgeons in the management of osteoporosis improves the rate of treatment at six months following a hip fracture.

Core needle biopsies of musculoskeletal tumors: potential pitfalls.

Core needle biopsy is a powerful tool used to diagnose and develop a treatment strategy for musculoskeletal tumors. With accuracy rates reported between 69% and 99%, it is evident that errors in diagnosis occur, and they can lead to devastating consequences. We reviewed pathology reports of preoperative core needle biopsies in an attempt to determine factors associated with false negative diagnoses for the purpose of improving surgical planning. We retrospectively reviewed all office-based core needle biopsies accomplished in our practice over a 6-year period. One hundred nineteen biopsies were identified, of which 82 fulfilled criteria to be included in the study population. The pathologist's report of each biopsy was reviewed and categorized based on the findings into 1 of 2 diagnostic groups: neoplastic or nonneoplastic. The results of the biopsies were then compared to the pathology results of the final surgical resection, and the rates and nature of false negative biopsy results (unrecognized malignant pathology) were compared for each group. Seventy-one biopsies were categorized as neoplastic based on the pathology report. No false negative results were found in this group when compared to the final surgical resection pathology. Eleven biopsies were categorized as nonneoplastic, of which 6 were found to be false negatives when compared to the final surgical pathologic diagnosis. The rate of false negative results significantly increased in biopsies whose reports were categorized as nonneoplastic compared to biopsies categorized as neoplastic (P<.0001). We found core needle biopsies of musculoskeletal lesions to be safe and effective in diagnosing pathologic processes. In cases in which analysis of the biopsy specimen did not identify a specific neoplastic process, we found a high incidence of undiagnosed malignancy upon definitive surgical resection. Pathology reports of core needle biopsies that specify only normal, inflammatory, or other nonspecific tissue descriptions should alert the clinician to the increased possibility of a false negative result, and require further tissue analysis.

Metastatic disease of the spine.

Metastatic spine disease accounts for 10% to 30% of new cancer diagnoses annually. The most frequent presentation is axial pain. A thorough spinal examination includes assessment of local tenderness, deformity, limitation of motion, and signs of nerve root or cord compression. Plain radiographs are obtained routinely; for a suspected or known malignancy, radionuclide studies are essential. Magnetic resonance imaging is more specific than bone scans. Computed tomography-guided biopsy is considered to be safe and accurate for evaluating spinal lesions. Treatment is multidisciplinary, and virtually all treatment is palliative. Management is guided by three key issues: neurologic compromise, spinal instability, and individual patient factors. Site-directed radiation, with or without chemotherapy, is the mainstay of treating painful lesions that are not impinging on neural elements. New data documenting the benefit of surgical decompression using improved techniques such as anterior approaches have amplified the role of the spine surgeon in the care of these patients.