The practicing orthopedic surgeon's guide to managing long bone metastases

Carbon vs. Titanium Nails in the Treatment of Impending and Pathological Fractures: A Literature Review

Background: Long bones are commonly affected by musculoskeletal tumors, but they also represent one of the most frequent locations for metastases. The treatment is based on pain management and the prevention or stabilization of pathological fractures by intramedullary nailing. While titanium nails are probably the most used, carbon-fiber-reinforced (CFR) nails have emerged as a new option for oncological patients. The aim of this review is to compare titanium and CFR nails according to current findings. Methods: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards were followed: a total of 1004 articles were identified and 10 were included. Results: Traditionally, titanium implants are highly valued for their optimal biomechanical properties and ease of insertion, facilitated by their radiopacity. However, the use of titanium poses challenges in radiotherapy due to interference with radiation dosage and the creation of ferromagnetic artifacts. Conversely, CFR implants have emerged as a recommended option for intramedullary fixation, due to their biomechanical and structural properties and their benefits during radiotherapy and follow-up monitoring X-ray. Conclusions: CFR nailing represents a promising advancement in the surgical management of oncological patients with long bone metastases. However, further studies are needed to increase surgeons' confidence in their use.

Outcome of Endoprosthesis used in Limb Salvage Surgery in a Malaysian Orthopaedic Oncology Centre

Introduction

To describe the duration of survival among bone tumour patients with endoprosthesis reconstruction and to determine frequency of implant failure, revision of surgery, and amputation after endoprosthesis reconstruction.

Materials and methods

A retrospective cross-sectional review of all patients with either primary bone tumour or secondary bone metastases treated with en bloc resection and endoprosthesis reconstruction from January 2008 to December 2020.

Results

A total of 35 failures were recorded among the 27 (48.2%) patients with endoprostheses. Some of the patients suffered from one to three types of modes of failure on different timelines during the course of the disease. Up to eight patients suffered from more than one type of failure throughout the course of the disease. Out of all modes of failure, local recurrence (type 5 failure) was the most common, accounting for 25.0% of all failure cases. Four patients (7.1%) eventually underwent amputation, which were either due to infection (2 patients) or disease progression causing local recurrence (2 patients).

Conclusion

The overall result of endoprosthesis reconstruction performed in our centre was compatible with other centres around the world. Moreover, limb salvage surgery should be performed carefully in a selected patient group to maximise the benefits of surgery.

A microfluidic organ-on-a-chip: into the next decade of bone tissue engineering applied in dentistry

A comprehensive understanding of the complex physiological and pathological processes associated with alveolar bones, their responses to different therapeutics strategies, and cell interactions with biomaterial becomes necessary in precisely treating patients with severe progressive periodontitis, as a bone-related issue in dentistry. However, existing monolayer cell culture or pre-clinical models have been unable to mimic the complex physiological, pathological and regeneration processes in the bone microenvironment in response to different therapeutic strategies. In this point, 'organ-on-a-chip' (OOAC) technology, specifically 'alveolar-bone-on-a-chip', is expected to resolve the problems by better imitating infection site microenvironment and microphysiology within the oral tissues. The OOAC technology is assessed in this study toward better approaches in disease modeling and better therapeutics strategy for bone tissue engineering applied in dentistry.

Evaluation of patients with pathological fractures treated by standard trauma principles but neglecting the underlying malign bone disease

INTRODUCTION

There are several studies in the literature about pathological fractures but almost no information about patients whose pathological fracture caused by a malignant lesion misdiagnosed and treated as a simple fracture. The aim of this study was to investigate patient and fracture characteristics, and outcomes in cases where fractures occurred in the presence of a malign pathology but were treated as simple fractures.

PATIENTS AND METHODS

Cases of malign bone lesions between 2000 and 2020 were retrospectively reviewed. Patients with a final diagnosis of malign bone lesion but whose pathological fractures were treated ignoring the underlying malign bone disease were included. Demographic, clinical and outcome data were collected from patient's medical records and analyzed.

RESULTS

Six patients met the inclusion criteria. Three of the patients were female and the cohort mean age was 56.8 ± 21.8 years at the time of admission. Patient diagnoses were: renal cell carcinoma metastasis (n = 1); colon cancer metastasis (n = 1); chondrosarcoma (n = 2); osteosarcoma (n = 1); and undifferentiated pleomorphic sarcoma of bone (n = 1). In all cases surgical management differed from those that should have been applied if the pathological fracture had been identified. Furthermore, surgical management after definitive histological diagnosis were more aggressive compared to if the malignancy had been identified at first admission. All patients died after a mean follow-up of 16.67 ± 11.7 months and the complication rate was 100%.

CONCLUSION

When a pathological fracture is misdiagnosed and managed as a simple bone fracture, outcomes are extremely poor. In these situations, remedial surgery is more extensive, with increased complication rates and there is poor life expectancy.

Intramedullary nailing for impending or pathologic fracture of the long bone: titanium vs carbon fiber peek nailing

Purpose

Methods

Results

Conclusions

Treatment of Bone Metastasis

The incidence of metastatic bone disease is increasing, as patients with cancer are living longer [...]

A Tailored Approach for Appendicular Impending and Pathologic Fractures in Solid Cancer Metastases

Simple Summary

Patients with bone metastases often suffer with complications, such as bone fractures, which have a substantial negative impact on clinical outcomes. To optimize clinical results, a tailored approach should be defined for managing impending or pathologic fractures in each individual case. The ability to control systemic disease, the extent, location and nature of bone metastases, and the biology of the underlying tumor, are the main factors that will define the strategy to follow.

Abstract

Advances in medical and surgical treatment have played a major role in increasing the survival rates of cancer patients with metastatic bone disease. The clinical course of patients with bone metastases is often impaired by bone complications, such as bone fractures, which have a substantial negative impact on clinical outcomes. To optimize clinical results and prevent a detrimental impact on patients’ health, a tailored approach should be defined for any given patient. The optimal management of impending or pathologic fractures is unknown and relies on a multidisciplinary approach to tailor clinical decisions to each individual patient. The ability to control systemic disease, the extent, location and nature of bone metastases, and the biology of the underlying tumor, are the main factors that will define the strategy to follow. The present review covers the most recent data regarding impending and pathologic fractures in patients with bone metastases, and discusses the medical and surgical management of patients presenting with metastatic bone disease in different clinical settings.

Better pain control with 8-gray single fraction palliative radiotherapy for skeletal metastases: a Bayesian network meta-analysis

External Beam Radiotherapy (EBRT) allows remarkable pain control in patients with skeletal metastases. We performed a Bayesian network meta-analysis comparing the most commonly used radiotherapy regimens for palliative management in patients with skeletal metastases. The main online databases were accessed in October 2020. All randomized clinical trials evaluating the irradiation of painful bone metastases were considered. The following irradiation patterns were analysed and included in the present network meta-analysis: 8 Gy- and 10 Gy/single fraction, 20 Gy/5 fractions, 30 Gy/10 fractions. The Bayesian hierarchical random-effect model analysis was adopted in all comparisons. The Log Odds-Ratio (LOR) statistical method for dichotomic data was adopted for analysis. Data from 3595 patients were analysed. The mean follow-up was 9.5 (1 to 28) months. The cumulative mean age was 63.3 ± 2.9. 40.61% (1461 of 3595 patients) were female. The 8Gy/single fraction protocol detected reduced rate of “no pain response” (LOR 3.39), greater rate of “pain response” (LOR-5.88) and complete pain remission (LOR-7.05) compared to the other dose patterns. The 8Gy group detected a lower rate of pathological fractures (LOR 1.16), spinal cord compression (LOR 1.31) and re-irradiation (LOR 2.97) compared to the other dose patterns. Palliative 8Gy/single fraction radiotherapy for skeletal metastases shows outstanding results in terms of pain control, re-irradiations, pathological fractures and spinal cord compression, with no differences in terms of survivorship compared to the other multiple dose patterns.

Level of evidence: I, Bayesian network meta-analysis of RCTs.

Bone cement as a local chemotherapeutic drug delivery carrier in orthopedic oncology: A review

Metastatic bone lesions are common among patients with advanced cancers. While chemotherapy and radiotherapy may be prescribed immediately after diagnosis, the majority of severe metastatic bone lesions are treated by reconstructive surgery, which, in some cases, is followed by postoperative radiotherapy or chemotherapy. However, despite recent advancements in orthopedic surgery, patients undergoing reconstruction still have the risk of developing severe complications such as tumor recurrence and reconstruction failure. This has led to the introduction and evaluation of poly (methyl methacrylate) and inorganic bone cements as local carriers for chemotherapeutic drugs (usually, antineoplastic drugs (ANPDs)). The present work is a critical review of the literature on the potential use of these cements in orthopedic oncology. While several studies have demonstrated the benefits of providing high local drug concentrations while minimizing systemic side effects, only six studies have been conducted to assess the local toxic effect of these drug-loaded cements and they all reported negative effects on healthy bone structure. These findings do not close the door on chemotherapeutic bone cements; rather, they should assist in materials selection when designing future materials for the treatment of metastatic bone disease.

Surgical management of proximal femoral metastasis: Fixation or hip replacement? A 309 case series

INTRODUCTION

The proximal femur is the most frequent operative site for metastasis, but there is no consensus between internal fixation and hip replacement. The present multicenter retrospective observational study sought: (1) to compare early clinical results between internal fixation and hip replacement for proximal femoral metastasis (PFM), and (2) to assess events affecting survival.

HYPOTHESIS

The study hypothesis was that internal fixation and hip replacement give comparable clinical results, operative site complications rates and survival.

MATERIAL AND METHODS

The series comprised 309 cases, 10 of which were bilateral, in 182 females and 117 males, with a mean age of 67.2±11.5 years and 62.5±13.2 years, respectively. Primaries were mainly breast (118; 38.2%), lung (85; 25.5%) or kidney (40; 12.9%). PFM was revelatory in 114 cases (36.9%). There was visceral involvement in 142 patients (46%), multiple peripheral bone involvement in 212 (68.6%), and spinal involvement in 134 (43.4%). There were 124 pathologic fractures (40%), 51 of which were revelatory. Metastases were cervicocephalic in 135 cases (43.7%), metaphyseal in 166 (53.7%) and both in 8 (2.6%). PFM was osteolytic in 90% of cases, managed by hip replacement in 161 cases and internal fixation in 148 (12 screwed plates, 136 nails). Seventy-seven patients had postoperative radiation therapy.

RESULTS

After hip replacement (n=144), walking was normal in 35 cases (24.3%), impaired but unassisted in 53 (36.8%), with 1 forearm crutch in 24 (16.6%), 2 crutches or a frame in 26 (18%), and impossible in 6 (4.1%). After nailing (n=125), results were respectively 38 (30.4%), 47 (37.6%), 15 (12%), 18 (14.4) and 7 (5.6%). Recovery of normal walking capacity did not significantly differ according to technique (p=0.162); nor did pain or function. Recovery of normal walking capacity was better after preventive surgery (p<0.001). Perioperative complications comprised: 10 cases of severe blood loss, 7 pulmonary embolisms, 6 digestive hemorrhages, and 5 lung infections. Secondarily, there were 11 infections (7 after hip replacement, 2 after nailing, 2 after plate fixation), 7 progressive osteolyses and 5 fractures. Complications rates were significantly higher with plate fixation, with no difference between nailing and hip replacement. Survival did not significantly differ between hip replacement (12 months [95% CI: 7-19]), nailing (7 months [95% CI: 6-11]) and plate fixation (16 months [95% CI: 6-not calculable]).

CONCLUSIONS

Clinical results and survival were comparable between hip replacement and nailing, confirming the study hypothesis, in agreement with the literature. Each technique has its indications. Patients with severely impaired walking capacity benefited greatly from surgery. The importance of preventive surgery was highlighted.

LEVEL OF EVIDENCE

IV, retrospective study.

Surgical treatment of peri-acetabular metastatic disease: Retrospective, multicentre study of 91 THA cases

INTRODUCTION

The occurrence of peri-acetabular metastasis (PAM) is a turning point in the progression of cancer because the disabling pain prevents the patient from walking or makes it difficult. Recent progress in controlling cancers that spread to the bone and controlling local bone destruction justify this national study. Since the data in France is incomplete or based on small studies, we analysed a multicentre retrospective cohort of patients with PAM who underwent total hip arthroplasty (THA) to evaluate 1) the clinical and radiological outcomes and 2) the factors impacting patient survival.

HYPOTHESIS

The clinical outcomes, complication rate and survivorship are comparable to that of recent published studies.

METHODS

Ninety-one patients (27 men, 64 women) with a mean age of 62.7±10.5 years (extremes 38 and 88) with PAM secondary to breast cancer [42 patients (46%)] or lung cancer [20 patients (22%)] underwent THA. The metastasis was the first sign of cancer in 33 cases (36%). Concurrent visceral metastases were present in 30 patients (33%), multiple peripheral bone metastasis in 48 patients (53%) and synchronous spine metastasis in 39 patients (43%). The most common construct was a cemented stem with metal reinforcement cage and cemented dual mobility cup [71 times (78%), while 85/91 had a dual mobility cup (93%)].

RESULTS

Elimination or reduction of pain was reported in 81 patients (91%). Overall walking ability was deemed normal or acceptable in 74 patients (83%). Six patients died (7%) before the end of the 3rd month. There were seven general complications (8%) including five thromboembolic events. There were 22 complications related to the surgical procedure in 20 patients (22%) that required surgical revision, including 10 surgical site infections (11%) and 3 dislocations (3%) (one concerning a dual mobility cup and 2 after single mobility cup). The median survivorship all causes combined was 19.5 months; it was 23.7 months for patients with breast cancer and 8.9 months for those with lung cancer.

CONCLUSION

Despite different endpoints being used, the clinical outcomes in our study are like those in other published studies, as were the incidence of surgery-related complications and the survivorship. The recommended surgical technique is the implantation of an acetabular reinforcement cage, curettage with cement filling of osteolytic areas, dual mobility cup and cemented stem followed by radiation therapy. The role of THA versus interventional radiology procedures must still be determined.

LEVEL OF EVIDENCE

IV, retrospective study without control group.

Functional results and survival after surgery for peripheral skeletal metastasis: A 434-case multicenter retrospective series

INTRODUCTION

Peripheral skeletal metastasis (PSM) has a negative impact on quality of life. New treatments for the primary tumor or the osteolysis hold out hope of improved survival. The few published French series were small, and we therefore undertook a multicenter retrospective analysis of PSM surgery between 2005 and December 2016, with the aim of assessing: 1) rate and type of complications, 2) functional results, and 3) overall survival and corresponding risk factors.

HYPOTHESIS

The French data for clinical results, survival and complications are in agreement with the international literature.

MATERIALS AND METHOD

The series comprised 391 patients with 434 metastatic locations. There was female predominance: 247 women (63%). Two sites were treated in 46 patients (12%), and three in 5. The main etiologies were breast cancer (151/391: 39%), lung cancer (103/391: 26%) and kidney cancer (52/391: 13%). There was synchronous visceral metastasis in 166 patients (42.5%), other peripheral locations in 137 (35%) and spinal location in 142 (39%). One hundred (27%) had ASA score>3; 61 (16%) had WHO score>3. The reason for surgery was pathologic fracture (n=137: 35%). Locations were femoral (274: 70%), acetabular (58: 15%), humeral (40: 0%), tibial (12: 3%) or other (7: 2%).

RESULTS

There were surgery site complications in 41 patients (9.4%), including 13 surgery site infections, and general complications in 47 patients (11%), including 11 cases of thromboembolism, 6 of blood loss, 9 pulmonary complications and 6 perioperative deaths. Overall survival, taking all etiologies and sites together, was 10 months (range, 5 days to 9 years; 95% CI, 8-13 months), and significantly better in females (14 versus 6 months; p=0.01), under-65 year-olds (p=0.001), and in preventive surgery versus fractured PSM (p=0.001). Median survival was 22 months (95% CI, 17-28 months) after breast cancer, 3 months (95% CI, 2-5 months) after lung cancer, and 17 months (95% CI, 8-58 months) after kidney cancer. Preoperatively, walking was impossible for 143 patients (38%), versus 23 (6.5%) postoperatively; 229 patients (63.5%) could walk normally or nearly normally after surgery, versus 110 (28%) before. After surgery, 3 patients (6%) were not using their operated upper limb, versus 27 (45%) before; 30 patients (54%) had normal upper limb use after surgery, versus 8 (5%) before.

CONCLUSION

The study hypothesis was on the whole confirmed in terms of survival according to type of primary and whether surgery was indicated preventively or for fracture.

LEVEL OF EVIDENCE

IV, retrospective study without control group.

Bone metastases: a comprehensive review of the literature

The last report of the World Health Organization (WHO) stated that approximately four million people experience bone pain due to malignant diseases. Among them, metastatic bone pain is one of the most important sources of complaint. The estimated median survival in the presence of bone metastases ranks from 10 to 12 weeks. Bone represents a potential target of distant metastases for the majority of malignant tumours. However, the exact incidence of bone metastases is unknown. Bone metastases have an important socio-economic impact, and due to the enhancement of the overall survivorship, their incidence is increasing. Malignant neoplasms such as lung, thyroid, renal cancer, multiple myeloma, and melanoma often metastasize to the bone. Bone metastases commonly localize to the spinal column, pelvis, shoulder, and distal femur. The proper treatment for painful skeletal metastases is still unknown. Hence, the purpose of this review of the literature was to update current evidence concerning the aetiogenesis, biological behaviour, and treatment algorithms for painful skeletal metastases.

Molecular mechanisms and clinical management of cancer bone metastasis

As one of the most common metastatic sites of malignancies, bone has a unique microenvironment that allows metastatic tumor cells to grow and flourish. The fenestrated capillaries in the bone, bone matrix, and bone cells, including osteoblasts and osteoclasts, together maintain the homeostasis of the bone microenvironment. In contrast, tumor-derived factors act on bone components, leading to subsequent bone resorption or excessive bone formation. The various pathways involved also provide multiple targets for therapeutic strategies against bone metastases. In this review, we summarize the current understanding of the mechanism of bone metastases. Based on the general process of bone metastases, we specifically highlight the complex crosstalk between tumor cells and the bone microenvironment and the current management of cancer bone metastases.

The PI3K inhibitor buparlisib suppresses osteoclast formation and tumour cell growth in bone metastasis of lung cancer, as evidenced by multimodality molecular imaging

Non‑small cell lung cancer (NSCLC) metastasis commonly occurs in bone, which often results in pathological fractures. Sustained phosphoinositide‑3‑kinase (PI3K) signalling promotes the growth of PI3K‑dependent NSCLC and elevates osteoclastogenic potential. The present study investigated the effects of a PI3K inhibitor on NSCLC growth in bone and osteoclast formation, and aimed to determine whether it could control symptoms associated with bone metastasis. A bone metastasis xenograft model was established by implanting NCI‑H460‑luc2 lung cancer cells, which contain a phosphatidylinositol‑​4,5‑bisphosphate 3‑kinase catalytic subunit α mutation, into the right tibiae of mice. After 1 week, the tumours were challenged with a PI3K inhibitor (buparlisib) or blank control for 3 weeks. Tumour growth and burden were longitudinally assessed in vivo via reporter gene bioluminescence imaging (BLI), small animal positron emission tomography/computed tomography (CT) [18F‑fluorodeoxyglucose (18F‑FDG)] and single‑photon emission computed tomography/CT [99mTc‑methylene diphosphonate (99mTc‑MDP)] imaging. Tibia sections of intraosseous NCI‑H460 tumours were analysed by immunohistochemistry (IHC), western blotting and flow cytometry. Dynamic weight bearing (DWB) tests were further performed to examine the improvement of symptoms associated with bone metastasis during the entire study. Administration of buparlisib significantly inhibited the progression of bone metastasis of NSCLC, as evidenced by significantly reduced uptake of 18F‑FDG, 99mTc‑MDP and BLI signals in the treated lesions. In addition, buparlisib appeared to inhibit the expression of tartrate‑resistant acid phosphatase and receptor activator of nuclear factor‑κB ligand, as determined by IHC. Buparlisib also resulted in increased cell apoptosis, as determined by a higher percentage of Annexin V staining and increased caspase 3 expression. Furthermore, buparlisib significantly increased weight‑bearing capacity, as revealed by DWB tests. The PI3K inhibitor, buparlisib, suppressed osteoclast formation in vivo, and exhibited antitumour activity, thus leading to increased weight‑bearing ability in mice with bone metastasis of lung cancer. Therefore, targeting the PI3K pathway may be a potential therapeutic strategy that prevents the structural skeletal damage associated with bone metastasis of lung cancer.

Early Clinical and Economic Outcomes of Prophylactic and Acute Pathologic Fracture Treatment

INTRODUCTION:

Pathologic fractures often contribute to adverse events in metastatic bone disease, and prophylactic fixation offers to mitigate their effects. This study aims to analyze patient selection, complications, and in-hospital costs that are associated with prophylactic fixation compared with traditional acute fixation after completed fracture.

MATERIALS AND METHODS:

The Nationwide Inpatient Sample database was queried from 2002 to 2014 for patients with major extremity pathologic fractures. Patients were divided by fixation technique (prophylactic or acute) and fracture location (upper or lower extremity). Patient demographics, comorbidities, complications, hospitalization length, and hospital charges were compared between cohorts. Preoperative variables were analyzed for potential confounding, and χ2 tests and Student’s t tests were used to compare fixation techniques.

RESULTS:

Cumulatively, 43,920 patients were identified, with 14,318 and 28,602 undergoing prophylactic and acute fixation, respectively. Lower extremity fractures occurred in 33,582 patients, and 10,333 patients had upper extremity fractures. A higher proportion of prophylactic fixation patients were white ( P = .043), male ( P = .046), age 74 years or younger ( P < .001), and privately insured ( P < .001), with decreased prevalence of obesity ( P = .003) and/or preoperative renal disease ( P = .008). Prophylactic fixation was also associated with decreased peri- and postoperative blood transfusions ( P < .001), anemia ( P < .001), acute renal failure ( P = .010), and in-hospital mortality ( P = .031). Finally, prophylactic fixation had decreased total charges (−$3,405; P = .001), hospitalization length ( P = .004), and extended length of stay (greater than 75th percentile; P = .012).

CONCLUSION:

Prophylactic fixation of impending pathologic fractures is associated with decreased complications, hospitalization length, and total charges, and should be considered in appropriate patients.

A scoping review on the surgical management of metastatic bone disease of the extremities

Background

Management of metastatic bone disease of the extremities (MBD-E) is challenging, and surgical directions pose significant implications for overall patient morbidity and mortality. Recent literature reviews on the surgical management of MBD-E present a paucity of high-level evidence and global inconsistencies in study design. In order to steer productive research, a scoping review was performed to map and assess critical knowledge gaps.

Methods

The Arksey and O’Malley framework for scoping studies was followed. A comprehensive literature search identified a large body of literature pertaining to the surgical management of MBD-E. Study data and meta-data was extracted and presented using descriptive analytics and a thematic framework. Literature gaps were identified and analyzed.

Results

Three hundred eighty five studies from 1969 to 2017 were included. Studies were categorized into 11 separate themes, with the majority (63%) falling into the “surgical fixation strategies” theme, followed by “complications” at 7% and “prognosis and survival” at 6.2%. Less than 3% of studies were categorized in “patient related outcomes” or “epidemiology” themes. 89% of studies were retrospective and only 6 studies were of level 1 or 2 evidence. We identified a temporal increase in publication by decade, and all studies published on interventional radiology techniques or economic analyses were published after 2007 or 2009, respectively. 64.9% of studies were published in Europe and 20.3% were published in North America. Average patient age was 62 (± 5.2 years), and breast was the most common primary tumour (28%), followed by lung (17%) and kidney (15%). In terms of surgical location, 75% of operations involved the femur, followed by the humerus at 22% and tibia at 3%.

Conclusions

We present a descriptive overview of the current published literature on the surgical management of MBD-E. Critical knowledge gaps have been identified through the development of a thematic framework. Consolidation of literary gaps must involve bolstered efforts towards patient and family-engaged research initiatives and assessment of patient-related surgical outcomes. Multi-disciplinary engagement in developing prospective research will also help guide evidence-based personalized practice for these patients. By building on existing comprehensive patient databases and registries, knowledge on survival and prognostic parameters can be greatly improved.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2210-8) contains supplementary material, which is available to authorized users.

Pathological fracture risk assessment in patients with femoral metastases using CT-based finite element methods. A retrospective clinical study

Physician recommendation for prophylactic surgical fixation of a femur with metastatic bone disease (MBD) is usually based on Mirels' criteria and clinical experience, both of which suffer from poor specificity. This may result in a significant number of these health compromised patients undergoing unnecessary surgery. CT-based finite element analyses (CTFEA) have been shown to accurately predict strength in femurs with metastatic tumors in an ex-vivo study. In order to assess the utility of CTFEA as a clinical tool to determine the need for fixation of patients with MBD of the femur, an ad hoc CTFEA was performed on a retrospective cohort of fifty patients. Patients with CT scans appropriate for CTFEA analysis were analyzed. Group 1 was composed of 5 MBD patients who presented with a pathologic femoral fracture and had a scan of their femurs just prior to fracture. Group 2 was composed of 45 MBD patients who were scheduled for a prophylactic surgery because of an impending femoral fracture. CTFEA models were constructed for both femurs for all patients, loaded with a hip contact force representing stance position loading accounting for the patient's weight and femur anatomy. CTFEA analysis of Group 1 patients revealed that they all had higher tumor associated strains compared to typical non-diseased femur bone strains at the same region (>45%). Based on analysis of the 5 patients in Group 1, the ratio between the absolute maximum principal strain in the vicinity of the tumor and the typical median strain in the region of the tumor of healthy bones (typical strain fold ratio) was found to be the 1.48. This was considered to be the predictive threshold for a pathological femoral fracture. Based on this typical strain fold ratio, twenty patients (44.4%) in Group 2 were at low risk of fracture and twenty-five patients (55.5%) high risk of fracture. Eleven patients in Group 2 choose not to have surgery and none fractured in the 5month follow-up period. CTFEA predicted that seven of these patients were below the pathological fracture threshold and four above, for a specificity of 63% Based on CTFEA, 39% of the patients with femoral MBD who were referred and underwent prophylactic stabilization may not have needed surgery. These results indicate that a prospective randomized clinical trial evaluating CTFEA as a criterion for determining the need for surgical stabilization in patients with MBD of the femur may be warranted.

Use of minimally invasive spine surgical instruments for the treatment of bone tumors

INTRODUCTION

Orthopedic oncologists often encounter patients with minor bony lesions that are difficult to access surgically and therefore require large exposures out of proportion to the severity of disease that confer significant patient morbidity. Minimally invasive surgical techniques offer the advantage of smaller incisions, shorter operative times, decreased tissue damage, and decreased costs. A variety of surgical procedures have emerged using minimally invasive technologies, particularly in the field of spine surgery. Areas covered: In this article, we describe the Minimal Exposure Tubular Retractor (METRx^TM) System which is a minimally invasive surgical device that utilizes a series of dilators to permit access to a surgical site of interest. This system was developed for use in treatment of disc herniation, spinal stenosis, posterior lumbar interbody fusion, transforaminal lumbar interbody fusion and spinal cord stimulation implantation. We also describe novel uses of this system for minimally invasive biopsy and treatment of benign and metastatic bone lesions at our institution. Expert commentary: Minimally invasive surgical techniques will continue to expand into the field of orthopedic oncology. With a greater number of studies proving the safety and effectiveness of this technique, the demand for minimally invasive treatments will grow.

Carbon-fiber reinforced intramedullary nailing in musculoskeletal tumor surgery: a national multicentric experience of the Italian Orthopaedic Society (SIOT) Bone Metastasis Study Group

INTRODUCTION

Carbon fiber reinforced (CFR) implants have been proposed for the treatment of fractures or impending fractures of the long bones in the oncology patient. Aim of this study is to present the largest cohort of oncology patients operated by CFR nailing by the Italian Orthopaedic Society (SIOT) Bone Metastasis Study Group.

METHODS

53 adult oncology patients were operated on with a CFR-PEEK nail. All the data from adjuvants therapies were collected. Bone callus formation, response to radiotherapy, relapse or progression of the osteolysis were recorded. Hardware survival and failure, breakage and need for implant revision were also analysed.

RESULTS

Anatomical implantation of nails include humerus (n = 35), femur (n =11) and tibia (n = 7). The most frequent tumors affecting the bone were myeloma (n = 13), breast (n = 11), lung (n = 8), and renal cell cancer (n = 7). Acrylic cement reinforcement was used in 2 patients. One patient was subjected to electrochemotherapy after nail insertion. Intraoperative and early postoperative complications occurred in 13.2% and 7.54% of patients respectively. Eight patients had local progression and one developed a stress fracture proximally to the distal static screw. Radiographic union occurred in 14 patients; one screw loosening was recorded.

DISCUSSION

There is currently a lack of solid evidence on the clinical use of CFR nails in oncologic patients. This is the first and largest study of CFR nailing, with the longest available follow up.

CONCLUSIONS

Implant related complications and surgery-related morbidity should be taken into account in the decision-making process for the surgical management of these patients. These data can improve the surgeon-patient communication and guide further studies on patients' survival and complications with respect to surgery.

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.

Treatment for long bone metastases based on a systematic literature review

PURPOSE

To provide treatment guidelines for patients with long bone metastatic disease based on a systematic review of the literature and to propose an algorithm to guide orthopedic surgeons in decision-making for these patients.

MATERIALS AND METHODS

We performed a computerized literature search in MEDLINE, EMBASE and Scopus for studies on patients with long bone metastases. We used the key words "long bones", "metastasis" and "treatment" for published studies that evaluated any treatment for long bone metastases. The articles found were then studied to determine the accuracy of surgical treatments for long bone metastases in every anatomic location, regardless of cancer type, stage and grade of the oncologic disease. Guidelines inferred from this literature review were collected, and an algorithm was proposed.

RESULTS

There was no clear evidence to support excision of a long bone metastatic lesion at the same surgical setting with internal fixation or prosthetic reconstruction. However, en bloc resection of an isolated bone metastasis may have a beneficial effect on survival. The life expectancy of the patients should be considered for any surgical treatment. Internal fixation preferably with reconstruction nails is indicated for meta-diaphyseal lesions; their rate of mechanical failure and complications ranges from 2 to 22 %. Prosthetic reconstruction is indicated for extensive lytic lesions or pathologic fractures in a meta-epiphyseal locations; their rate of mechanical failure and complications ranges from 3.7 to 35 %. Most of the internal fixation-related complications occur more than 1 year after treatment, in contrast to prosthetic reconstruction-related complications that may occur earlier.

CONCLUSIONS

Intramedullary nail fixation or prosthetic reconstruction should be chosen on the basis of the location of the lesion, the extent of bone destruction and the stability of the construct to outlast the expected life of the patient. Implant-related complication is similar but may occur earlier with prosthetic reconstructions.

New anti-resorptives and antibody mediated anti-resorptive therapy

The ageing population and an increase in both the incidence and prevalence of cancer pose a healthcare challenge, some of which is borne by the orthopaedic community in the form of osteoporotic fractures and metastatic bone disease. In recent years there has been an increasing understanding of the pathways involved in bone metabolism relevant to osteoporosis and metastases in bone. Newer therapies may aid the management of these problems. One group of drugs, the antibody mediated anti-resorptive therapies (AMARTs) use antibodies to block bone resorption pathways. This review seeks to present a synopsis of the guidelines, pharmacology and potential pathophysiology of AMARTs and other new anti-resorptive drugs. We evaluate the literature relating to AMARTs and new anti-resorptives with special attention on those approved for use in clinical practice. Denosumab, a monoclonal antibody against Receptor Activator for Nuclear Factor Kappa-B Ligand. It is the first AMART approved by the National Institute for Health and Clinical Excellence and the US Food and Drug Administration. Other novel anti-resorptives awaiting approval for clinical use include Odanacatib. Denosumab is indicated for the treatment of osteoporosis and prevention of the complications of bone metastases. Recent evidence suggests, however, that denosumab may have an adverse event profile similar to bisphosphonates, including atypical femoral fractures. It is, therefore, essential that orthopaedic surgeons are conversant with these medications and their safe usage.

TAKE HOME MESSAGE

Denosumab has important orthopaedic indications and has been shown to significantly reduce patient morbidity in osteoporosis and metastatic bone disease.

Treatment Planning and Fracture Prediction in Patients with Skeletal Metastasis with CT-Based Rigidity Analysis

PURPOSE

Pathologic fractures could be prevented if reliable methods of fracture risk assessment were available. A multicenter prospective study was conducted to identify significant predictors of physicians' treatment plan for skeletal metastasis based on clinical fracture risk assessments and the proposed CT-based Rigidity Analysis (CTRA).

EXPERIMENTAL DESIGN

Orthopedic oncologists selected a treatment plan for 124 patients with 149 metastatic lesions based on the Mirels method. Then, CTRA was performed, and the results were provided to the physicians, who were asked to reassess their treatment plan. The pre- and post-CTRA treatment plans were compared to identify cases in which the treatment plan was changed based on the CTRA report. Patients were followed for a 4-month period to establish the incidence of pathologic fractures.

RESULTS

Pain, lesion type, and lesion size were significant predictors of the pre-CTRA plan. After providing the CTRA results, physicians changed their plan for 36 patients. CTRA results, pain, and primary source of metastasis were significant predictors of the post-CTRA plan. Follow-up of patients who did not undergo fixation resulted in 7 fractures; CTRA predicted these fractures with 100% sensitivity and 90% specificity, whereas the Mirels method was 71% sensitive and 50% specific.

CONCLUSIONS

Lesion type and size and pain level influenced the physicians' plans for the management of metastatic lesions. Physicians' treatment plans and fracture risk predictions were significantly influenced by the availability of CTRA results. Due to its high sensitivity and specificity, CTRA could potentially be used as a screening method for pathologic fractures.