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.

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.].

Molecular Targeted Therapy Approach to Musculoskeletal Tumors.

The future of cancer treatment is promising. Although marred by years of plateau in outcomes, new avenues have been identified that are poised to change how we treat cancer. Molecular targeted therapy or targeted therapy is one of these methods. Molecular targeted therapy involves identifying specific pathways or markers that allow cancer cells to flourish. Once identified, specific molecules can be used to block proliferative pathways, thereby negatively impacting tumor growth. Targeting specific pathways that prolong the survival of the cancer cell can lead to a decreased cancer burden, and improved patient outcomes. This article reviews the tenets of molecular targeted therapy, common pathways, target acquisition for drug development, and the pathways that have been elucidated in musculoskeletal tumors.

Own the Bone, a System-Based Intervention, Improves Osteoporosis Care After Fragility Fractures.

BACKGROUND: The goal of this study was to evaluate the effectiveness of the American Orthopaedic Association's Own the Bone secondary fracture prevention program in the United States. METHODS: The objective of this quality improvement cohort study was dissemination of Own the Bone and implementation of secondary prevention (osteoporosis pharmacologic and bone mineral density [BMD] test recommendations). The main outcome measures were the number of sites implementing Own the Bone and implementation of secondary prevention, i.e., orders for BMD testing and/or pharmacologic treatment. The 177 sites participating in the program were academic and community hospitals, orthopaedic surgery groups, and a health system; data were obtained from the first 125 sites utilizing its registry, between January 1, 2010, and March 31, 2015. It included all patients, aged 50 years or older, presenting with fragility fractures (n = 23,132) who were enrolled in the Own the Bone web-based registry. The interventions were education, development of program elements, dissemination, implementation, and evaluation of the Own the Bone program at participating sites. RESULTS: A growing number of institutions implemented Own the Bone (14 sites in 2005-2006 to 177 sites in 2015). After consultation, 53% of patients had a BMD test ordered and/or pharmacologic therapy for osteoporosis. CONCLUSIONS: The Own the Bone intervention has succeeded in improving the behaviors of medical professionals in the areas of osteoporosis treatment and counseling, BMD testing, initiation of pharmacotherapy, and coordination of care for patients who have experienced a fragility fracture.

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.

The role of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) in orthopaedic bone repair and regeneration.

Recombinant human PDGF BB homodimer (rhPDGF-BB) is a potent recruiter of, and strong mitogenic factor for, cells crucial to musculoskeletal tissue repair, including mesenchymal stem cells (MSCs), osteogenic cells and tenocytes. rhPDGF-BB also upregulates angiogenesis. These properties allow rhPDGF-BB to trigger the cascade of bone and adjoining soft tissue repair and regeneration. This mechanism of action has been established in numerous preclinical and clinical studies. Demonstration of the safety and efficacy of rhPDGF-BB in the healing of chronic foot ulcers in diabetic patients and regeneration of alveolar (jaw) bone lost due to chronic infection from periodontal disease has resulted in two FDA-approved products based on this molecule. A third product is in late stages of clinical development, with pilot and pivotal clinical studies of rhPDGF-BB mixed with an osteoconductive bone matrix (Augment(®) Bone Graft) in foot and ankle fusions demonstrating that this product is at least as effective as bone autograft, and has an improved safety profile. Additional combinations of rhPDGF-BB with tissue-specific matrices are also being studied clinically in additional musculoskeletal indications.

Recombinant human platelet-derived growth factor: biology and clinical applications.

The abilities of bone to remodel, fractures to repair, and bone grafts to incorporate are all fundamental reflections of the bone remodeling cycle. This process is characterized by the recruitment and differentiation of osteoblastic and osteoclastic cell populations, whose cellular activities are coordinated and regulated by an elaborate system of growth factors and cytokines. One of the crucial biological factors responsible for reparative osseous activity is platelet-derived growth factor (PDGF). The potent stimulatory effects of PDGF as a chemoattractant and mitogen for mesenchymal cells (including osteogenic cells), along with its ability to promote angiogenesis, have been demonstrated in a variety of preclinical models predicting maxillofacial, spine and appendicular skeletal, and soft-tissue applications. The biological profile of PDGF, including its ability to recruit osteoprogenitor cells, makes it particularly suited to address the skeletal defects that are seen with comorbid conditions such as osteoporosis, diabetes, and the effects of smoking. The clinical success and safety that have been demonstrated with use of recombinant human PDGF (rhPDGF) in the repair of periodontal defects have led to U.S. Food and Drug Administration (FDA) approval of rhPDGF for this indication. Ongoing pilot and pivotal trials in the United States and internationally will continue to clarify the promising role of PDGF in the treatment of challenging skeletal disorders.

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.

Measuring the attitudes and impact of the eighty-hour workweek rules on orthopaedic surgery residents.

BACKGROUND: The literature on graduate medical education contains anecdotal reports of some effects of the new eighty-hour workweek on the attitudes and performance of residents. However, there are relatively few studies detailing the attitudes of large numbers of residents in a particular surgical specialty toward the new requirements. METHODS: Between July and November 2004, a survey created by the Academic Advocacy Committee of the American Academy of Orthopaedic Surgeons was distributed by mail, fax, and e-mail to a total of 4207 orthopaedic residents at the postgraduate year-1 through year-6 levels of training. The survey responses were tabulated electronically, and the results were recorded. RESULTS: The survey response rate was 13.2% (554 residents). Sixty-eight percent (337) of the 495 respondents whose postgraduate-year level was known were at the postgraduate year-4 level or higher. Attitudes concerning the duty rules were mixed. Twenty-three percent of the 554 respondents thought that eighty hours constituted an appropriate number of duty hours per week; 41% believed that eighty hours were too many, and 34% thought that eighty hours were not sufficient. Thirty-three percent of the respondents had worked greater than eighty hours during at least a single one-week period since the new rules were implemented; this occurred more commonly among the postgraduate year-3 and more junior residents. Orthopaedic trauma residents had the most difficulty adhering to the new duty-hour restrictions. Eighty-two percent of the respondents indicated that their residency programs have been forced to make changes to their call schedules or to hire ancillary staff to address the rules. The use of physician assistants, night-float systems, and so-called home-call assignments were the most common strategies used to achieve compliance. CONCLUSION: Resident attitudes toward the work rules are mixed. The rules have forced residency programs to restructure. Junior residents have more favorable attitudes toward the new standards than do senior residents. Self-reporting of duty hours is the most common method of monitoring in orthopaedic training programs. Such systems allow ample opportunity for inaccuracies in the measurement of hours worked. Although residents report an improved quality of life as a result of these new rules, the attitude that the quality of training is diminished persists.

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.

Posterolateral lumbar fusions in athymic rats: characterization of a model.

BACKGROUND CONTEXT: The athymic rat has been used to study the role of osteoinductive products in spinal fusions. This small animal model has been advocated to minimize potential inflammatory responses to allogeneic or xenogenic proteins. Despite past experience, this model has not yet been well characterized. PURPOSE: To further define and validate a posterolateral lumbar fusion model in the athymic rat. STUDY DESIGN/SETTING: Comparison of fusions after animal survival surgery. PATIENT SAMPLE: Forty athymic and 20 normothymic rats. OUTCOME MEASURES: Manual palpation, radiography and histology at 3 and 6 weeks. METHODS: Single-level intertransverse fusions were performed at the L4-L5 level of 40 athymic rats. Twenty rats were implanted with autograft (athymic/autograft), and 20 had no graft placed (athymic/no graft). An additional 20 autograft fusions were performed on normothymic rats (normothymic/autograft). Half were sacrificed at 3 weeks; half were sacrificed at 6 weeks. RESULTS: At 3 weeks, 0% of the athymic/no graft rats fused, 20% of the athymic/autograft rats fused and 20% of the normothymic/autograft rats fused by manual palpation. At 6 weeks, 0% of the athymic/no graft rats fused, 30% of the athymic/autograft rats fused and 40% of the normothymic/autograft rats fused by manual palpation. Radiographs were of limited utility in determining fusion, and histology results were roughly concordant with those of manual palpation. CONCLUSIONS: This work further characterizes the athymic rat posterolateral lumbar fusion model. The absence of a thymus does not appear to affect autograft fusion rates, and no spontaneous fusions were seen when no graft was placed.

Osteogenic protein-1 in treatment of tibial nonunions: current status.

Between 5% to 10% of tibial fractures progress to nonunion, causing substantial disability. Bone autografts, along with internal fixation, are the usual treatment for these failures, but the morbidity associated with autogenous tissues remains problematic. Bone morphogenetic proteins are currently available for clinical use and preclinical models, as well as an increasing number of patients treated with these molecules demonstrate their safety and efficacy. Osteogenic Protein-1, OP-1, has been evaluated in a randomized, prospective, multi-institution study of tibial nonunions. Sixty-one patients with 63 nonunions received OP-1 and intramedullary rod fixation, and were compared with 61 patients with 61 nonunions treated with fresh autogenous bone graft and the same fixation. Clinical outcomes (success in 81% of OP-1 and 85% of autograft-treated patients) and radiographic evaluation (healing in 75% of OP-1 and 84% of autograft-treated patients) were statistically indistinguishable at 9 months following treatment. No OP-1 or graft-related adverse events occurred. More than 20% of the autograft group had significant donor-site pain 6 months following surgery. OP-1 is a safe and effective alternative to autogenous bone in treatment of tibial nonunions.

Malignant bone tumors: limb sparing versus amputation.

Amputation, once the mainstay of treatment of malignant bone tumors, now is used selectively and infrequently. Most patients are candidates for limb-sparing procedures because of effective chemotherapeutic agents and regimens, improved imaging modalities, and advances in reconstructive surgery. Patient age as well as tumor location and extent of disease help define the most appropriate surgical alternatives. Options for skeletal reconstruction include modular endoprostheses, osteoarticular or bulk allografts, allograft-prosthetic composites, vascularized bone grafts, arthrodesis, expandable prostheses, rotationplasty, and limb-lengthening techniques. Two key factors must be considered: survival rates should be no worse than those associated with amputation, and the reconstructed limb must provide satisfactory function. Functional outcome studies comparing limb-sparing procedures and amputation have inherent limitations, including the inability to randomize treatment and the subjective nature of important outcome measures.