Imaging differentiation of pathologic fractures caused by primary and secondary bone tumors

Management of Pathologic Fractures around the Knee: Part 1-Distal Femur

Pathologic fractures secondary to metastatic disease are an increasingly prevalent problem. Such patients require multidisciplinary collaboration to optimize clinical outcomes. An established algorithm for clinical, laboratory, and radiographic work-up will ensure that each patient achieves the best outcome while avoiding catastrophic complications. Metastatic disease to the region of the knee is less commonly encountered than in other regions of the body, but it presents unique difficulties that merit discussion. Part one of this two-part article series will discuss the appropriate work-up of patients with suspected or impending pathologic fracture of the distal femur, highlight biopsy principles, address perioperative nonsurgical treatments that will optimize patient outcomes, and discuss available surgical treatment modalities.

Titanium Implants and Local Drug Delivery Systems Become Mutual Promoters in Orthopedic Clinics

Titanium implants have always been regarded as one of the gold standard treatments for orthopedic applications, but they still face challenges such as pain, bacterial infections, insufficient osseointegration, immune rejection, and difficulty in personalizing treatment in the clinic. These challenges may lead to the patients having to undergo a painful second operation, along with increased economic burden, but the use of drugs is actively solving these problems. The use of systemic drug delivery systems through oral, intravenous, and intramuscular injection of various drugs with different pharmacological properties has effectively reduced the levels of inflammation, lowered the risk of endophytic bacterial infection, and regulated the progress of bone tumor cells, processing and regulating the balance of bone metabolism around the titanium implants. However, due to the limitations of systemic drug delivery systems-such as pharmacokinetics, and the characteristics of bone tissue in the event of different forms of trauma or disease-sometimes the expected effect cannot be achieved. Meanwhile, titanium implants loaded with drugs for local administration have gradually attracted the attention of many researchers. This article reviews the latest developments in local drug delivery systems in recent years, detailing how various types of drugs cooperate with titanium implants to enhance antibacterial, antitumor, and osseointegration effects. Additionally, we summarize the improved technology of titanium implants for drug loading and the control of drug release, along with molecular mechanisms of bone regeneration and vascularization. Finally, we lay out some future prospects in this field.

Current Overview of Treatment for Metastatic Bone Disease

The number of patients with bone metastasis increases as medical management and surgery improve the overall survival of patients with cancer. Bone metastasis can cause skeletal complications, including bone pain, pathological fractures, spinal cord or nerve root compression, and hypercalcemia. Before initiation of treatment for bone metastasis, it is important to exclude primary bone malignancy, which would require a completely different therapeutic approach. It is essential to select surgical methods considering the patient’s prognosis, quality of life, postoperative function, and risk of postoperative complications. Therefore, bone metastasis treatment requires a multidisciplinary team approach, including radiologists, oncologists, and orthopedic surgeons. Recently, many novel palliative treatment options have emerged for bone metastases, such as stereotactic body radiation therapy, radiopharmaceuticals, vertebroplasty, minimally invasive spine stabilization with percutaneous pedicle screws, acetabuloplasty, embolization, thermal ablation techniques, electrochemotherapy, and high-intensity focused ultrasound. These techniques are beneficial for patients who may not benefit from surgery or radiotherapy.

[Treatment strategies for tumor-related pathological fractures of the extremities]

Pathological fractures of the extremities frequently lead to uncertainty with respect to the treatment strategy and timing. The origin of metastases is typically breast, bronchial, renal and prostate cancer and myelomas. Primary bone tumors play a subordinate role. The majority affect the femur, humerus and occasionally the tibia. Surgery is typically the first line treatment as healing under conservative treatment is unlikely. The most important goal is to relieve pain and the preservation or restoration of function. For correct assessment of indications, analysis of the fracture pattern and oncological aspects including dignity, entity, prognosis, metastatic status and the general condition of the patient need to be taken into consideration. Based on all these aspects the surgical approach can be chosen. Treatment options range from osteosynthetic stabilization and augmentation osteosynthesis up to endoprosthesis replacement. The treatment is carried out in an interdisciplinary procedure as additional measures need to be addressed in addition to the surgical treatment.

[Strategic approach to pathological fractures]

Pathological tumor-associated fractures are overall rare. They can occur in every age group and every bone. Although tumor-related fractures only form a small proportion of bone fractures, the early recognition of the cause of the fracture and treatment according to oncological guidelines are of enormous importance for affected patients. False treatment is frequently associated with far-reaching negative consequences with respect to the course of the disease. The great challenge is not the expeditious surgical treatment but much more the adequate diagnostics and the incorporation of local fracture treatment into an interdisciplinary overall oncological concept.

ACR Appropriateness Criteria® Rib Fractures

Rib fractures are the most common thoracic injury after minor blunt trauma. Although rib fractures can produce significant morbidity, the diagnosis of injuries to underlying organs is arguably more important as these complications are likely to have the most significant clinical impact. Isolated rib fractures have a relatively low morbidity and mortality and treatment is generally conservative. As such, evaluation with standard chest radiographs is usually sufficient for the diagnosis of rib fractures, and further imaging is generally not appropriate as there is little data that undiagnosed isolated rib fractures after minor blunt trauma affect management or outcomes. Cardiopulmonary resuscitation frequently results in anterior rib fractures and chest radiographs are usually appropriate (and sufficient) as the initial imaging modality in these patients. In patients with suspected pathologic fractures, chest CT or Tc-99m bone scans are usually appropriate and complementary modalities to chest radiography based on the clinical scenario. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Case series of patients with pathological dyaphiseal fractures from metastatic bone disease

INTRODUCTION

Fractures on pathologic bone have major impact on life quality. The appropriate treatment is not standardized, but the current literature delineates that surgery must provide adequate stabilization for the life expectancy. We aimed to review the epidemiology, treatment outcomes and survival in our department.

MATERIAL AND METHODS

The electronic database from a major referral centre was searched for patients treated for tumours and fractures by the corresponding ICM-10 codes over five years. Eighty-nine patients were identified. Eleven females and nine males, with an average age of 64 years underwent 23 operations during the selected timeframe. Six fractures were subtrochanteric, five at the femoral neck and five at the femoral diaphysis. Seventeen cases were metastatic carcinomas, out of which five mammary, three pulmonary and seven carcinomas of undetermined origin without immunohistochemistry.

RESULTS

Fourteen types of surgical intervention were osteosynthesis with intramedullary nails and six were partial hip replacements of which one had proximal femur resection and revision stem hemiarthroplasty. Four patients had single metastatic lesions which underwent resection and defect filling using PMMA cement (polymethylmethacrylate). The follow-up period ranged between two and seven years or until death. Only five patients (25%) were alive at the last follow-up. Local recurrence appeared in one patient. There was one immediate post-operative complication (dehiscent wound) and one implant failure after five years and was replaced with a larger diameter (exchange nailing).

CONCLUSION

Both hip arthroplasty and femoral nailing are safe and routine procedures that are performed with relatively technical ease and low surgical stress and few peri-operative complications for the patient. They allow for immediate mobilization and weight-bearing with moderate and rapidly decreasing pain and discomfort.

Metastatic fractures of long limb bones

The diagnosis of pathological fracture should be considered routinely in patients with long limb-bone fractures. Investigations must be performed to establish the diagnosis of pathological fracture then to determine that the bone lesion is a metastasis. In over 85% of cases, the clinical evaluation combined with a detailed analysis of the radiographs is sufficient to determine that the fracture occurred at a tumour site. Aetiological investigations establish that the tumour is a metastasis. In some patients, the diagnosis of metastatic cancer antedates the fracture. When this is not the case, a diagnostic strategy should be devised, with first- to third-line investigations. When these fail to provide the definitive diagnosis, a surgical biopsy should be performed. The primaries most often responsible for metastatic bone disease are those of the breast, lung, kidney, prostate, and thyroid gland. However, the survival gains provided by newly introduced treatments translate into an increased frequency of bone metastases from other cancers. The optimal treatment of a pathological fracture is preventive. The Mirels score is helpful for determining whether preventive measures are indicated. When selecting a treatment for a pathological fracture, important considerations are the type of tumour, availability of effective adjuvant treatments, and general health of the patient. Metastatic fractures are best managed by a multidisciplinary team. The emergent treatment should start with optimisation of the patient's general condition, in particular by identifying and treating metabolic disorders (e.g., hypercalcaemia) and haematological disorders. Treatment decisions also depend on the above-listed general factors, location of the tumour, and size of the bony defect. Prosthetic reconstruction is preferred for epiphyseal fractures and internal fixation for diaphyseal fractures.

Evaluation of the use of fluoroscopy guided needle biopsies for diagnosing cases of suspected pathological fractures

AIM

Establishing an early and accurate diagnosis in cases of suspected pathological fractures is crucial to initiate optimal treatment without delay. The use of percutaneous biopsy has become popular over the past few years. However, there is a paucity of information regarding the efficacy and safety of percutaneous biopsy procedures guided by fluoroscopy.

METHODS

A total of 137 percutaneous C-arm fluoroscopy-guided core needle biopsy (CNB) procedures were performed in 135 patients with suspected pathological fractures. The sensitivity, specificity, accuracy, and overall prognostic value of these procedures were evaluated. Complications, if any, were documented for all cases.

RESULTS

The overall sensitivity, specificity, and accuracy were 82.0%, 100%, and 83.2%, respectively. The positive and negative predictive value was 100% and 28.1%, respectively. There were 23 "false negative" cases in our study, of which 15 were benign lesions and eight were malignant tumors. No "false-positives" were found. Major procedure-related complications occurred in three patients (2.2%). These complications, however, did not alter the prognosis of these patients.

CONCLUSION

Percutaneous C-arm fluoroscopy-guided biopsy procedures are both effective and safe for diagnosis of suspected pathological fractures in the appendicular skeleton.

Treatment of pathologic fractures

Pathologic fractures occur in bone weakened by a disease process. In the hand, the most common cause of pathologic fracture is a solitary enchondroma, although many other less common causes exist, including bone cysts, benign and malignant tumors, and other rarer entities. Arriving at a correct diagnosis is the key to successful treatment. If the fracture seems the result of a benign process, the fracture can be allowed to heal prior to definitive treatment of the underlying lesion. Fractures associated with aggressive or malignant lesions require more urgent treatment, although the overall prognosis for pathologic fracture due to malignancy is poor.