The presence of metastatic bone disease (MBD) often necessitates major orthopaedic surgery. Patients will enter surgical care either through emergent or electively scheduled care pathways. Patients in a pain crisis or with an acute fracture are generally admitted via emergent care pathways whereas patients with identified high-risk bone lesions are often booked for urgent yet scheduled elective procedures. The purpose of this study is to compare the post-operative outcomes of patients who present through emergent or electively scheduled care pathways in patients in a Canadian health care system. We have conducted a retrospective, multicenter cohort study of all patients presenting for surgery for MBD of the femur, humerus, tibia or pelvis in southern Alberta between 2006 and 2021. Patients were identified by a search query of all patients with a diagnosis of metastatic cancer who underwent surgery for an impending or actual pathologic fracture in the Calgary, South and Central Alberta Zones. Subsequent chart reviews were performed. Emergent surgeries were defined by patients admitted to hospital via urgent care mechanisms and managed via unscheduled surgical bookings (“on call list”). Elective surgeries were defined by patients seen by an orthopaedic surgeon at least once prior to surgery, and booked for a scheduled urgent, yet elective procedure. Outcomes include overall survival from the time of surgery, hospital length of stay, and 30-day hospital readmission rate. We have identified 402 patients to date for inclusion. 273 patients (67.9%) underwent surgery through emergent pathways and 129 patients (32.1%) were treated through urgent, electively scheduled pathways. Lung, prostate, renal cell, and breast cancer were the most common primary malignancies and there was no significant difference in these primaries amongst the groups (p=0.06). Not surprisingly, emergent patients were more likely to be treated for a pathologic fracture (p<0.001) whereas elective patients were more likely to be treated for an impending fracture (p<0.001). Overall survival was significantly shorter in the emergent group (5.0 months, 95%CI: 4.0-6.1) compared to the elective group (14.9 months 95%CI: 10.4-24.6) [p<0.001]. Hospital length of stay was significantly longer in the emergent group (13 days, 95%CI: 12-16 versus 5 days, 95%CI: 5-7 days). There was a significantly greater rate of 30-day hospital readmission in the emergent group (13.3% versus 7.8%) [p=0.01]. Electively managed MBD has multiple benefits including longer post-operative survival, shorter length of hospital stay, and a lower rate of 30-day hospital readmission. These findings from a Canadian healthcare system demonstrate clinical value in providing elective orthopaedic care when possible for patients with MBD. Furthermore, care delivery interventions capable of decreasing the footprint of emergent surgery through enhanced screening or follow-up of patients with MBD has the potential to significantly improve clinical outcomes in this population. This is an ongoing study that will justify refinements to the current surgical care pathways for MBD in order to identify patients prior to emergent presentation. Future directions will evaluate the costs associated with each care delivery method to provide opportunity for health economic efficiencies

Surgical management for acute or impending pathologic fractures in metastatic bone disease (MBD) places patients at high-risk for post-operative venous thromboembolism (VTE). Due to the combination of malignancy, systemic cancer treatment, and surgical treatment, VTE-risk is increased 7-fold in patients with MBD compared to non-cancer patients undergoing the same procedure. The extent and duration of post-operative hypercoagulability in patients with MBD remains unknown and thromboprophylaxis guidelines were developed for non-cancer patients, limiting their applicability to address the elevated VTE-risk in cancer patients. Thrombelastography (TEG) analysis is a point-of-care test that measures clot formation, stabilization, and lysis in whole blood samples. The TEG parameter, maximal amplitude (MA), indicates clot strength and the threshold of ≥65 mm has been used to define hypercoagulability and predict VTE events in non-cancer patients requiring orthopaedic surgery. Therefore, this study aims to quantify the extent and duration of post-operative hypercoagulability in patients with MBD using serial TEG analysis. Consecutive adults (≥18 years) with MBD who required orthopaedic surgery for acute or impending pathologic fractures were enrolled into this single-centre, prospective cohort study. Serial TEG analysis was performed onsite using a TEG®6s haemostasis analyzer (Haemonetics Corporation, Boston, MA) on whole blood samples collected at seven timepoints: pre-operatively; on post-operative day (POD) 1, 3, and 5; and at 2-, 6-, and 12-weeks post-operatively. Hypercoagulability was defined as MA ≥65 mm. Participants received standardized thromboprophylaxis for four weeks and patient-reported compliance with thromboprophylaxis was recorded. VTE was defined as symptomatic DVT or PE, or asymptomatic proximal DVT, and all participants underwent a screening post-operative lower extremity Doppler ultrasound on POD3. Descriptive statistics were performed and difference between pre-operative MA values of participants with VTE versus no VTE was evaluated using Student's t-test (p≤0.05). Twenty-one participants (10 female; 47.6%) with a mean age of 70 ± 12 years were enrolled. Nine different primary cancers were identified amongst participants, with breast (23.8%), colorectal (19.0%), and lung cancer (14.3%) most frequently reported. Most participants (57.1%) were hypercoagulable pre-operatively, and nearly half remained hypercoagulable at 6- and 12-weeks post-operatively (47.1 and 46.7%, respectively). VTE occurred in 5 patients (23.8%) and mean MA was 68.1 ± 4.6 mm at the time of diagnosis. Mean pre-operative MA values were significantly higher (p=0.02) in patients who experienced VTE (68.9 ± 3.5 mm) compared to those who did not (62.7 ± 6.5 mm). VTE incidence was highest in the first week post-operatively, during which time four VTE events (80%) occurred. The proportion of patients in a hypercoagulable state increased at three consecutive timepoints, beginning on POD3 (85.0%), increasing on POD5 (87.5%), and peaking at 2-weeks post-operatively (88.9%). Current thromboprophylaxis guidelines do not consider cancer-associated risk factors that contribute to increased VTE incidence and prescription duration may be inadequate to address prolonged post-operative hypercoagulability in patients with MBD. The high rate of VTE events observed and sustained hypercoagulable state indicate that thromboprophylaxis may be prematurely terminated while patients remain at high risk for VTE. Therefore, extending thromboprophylaxis duration beyond 4-weeks post-operatively in patients with MBD warrants further investigation

The femur is a common site for skeletal metastases. The Gamma2 nail has proved effective in relieving pain and restoring function. Little data exists on the use of the Gamma3 Long Nail (GLN) in this condition. Improved instrumentation is suggested to reduce operative time and facilitate minimally invasive surgery. This study reports a series of patients treated in a District General Hospital. A retrospective casenote review was performed of all patients treated with the GLN for femoral metastatic disease over a five year period. Patients were followed-up for a minimum of one year. Functional level was assessed using the Parker Mobility Score (PMS). 12 patients underwent 15 nailings. Mean age was 75.4 years (median 75.7, range 61-92). In bilateral cases, the operations were performed during the same hospital admission. There were seven prophylactic nailings for impending fracture from proximal femoral lesions, seven procedures for actual fractures distal to the intertrochanteric line, and one basicervical fracture associated with multiple femoral metastases. Primaries were four prostate, two breast, two lung, one bowel, one bladder, one renal, and one myeloma. Average anaesthetic time for all procedures was 134 mins (median 125, range 90-210). Average peri-operative drop in serum haemoglobin was 2.3g/dL (median 2.1, range 0.6-4.8). Five patients with actual fracture and one patient with impending fracture required blood transfusion, receiving 2.2 units on average. In-hospital mortality rate was 0.83%, with only one patient not surviving to discharge. One year mortality was 83.3%. Only two patients were alive one year post-operation. Of the remaining patients, average survival was 3.2 months (median 3, range 1-6). Patients spent an average of 17 days on an acute orthopaedic unit (median 14, range 4-80). Two patients required further convalescence in a rehabilitation unit. There were three surgical complications. Two impending fractures became complete, One intra-operatively and one post-operatively. In the case of basi-cervical fracture, the proximal screw cut out of the femoral head, requiring revision to a long-stem bipolar hemiarthroplasty. This was the only re-operation required in this series. Average pre-operative PMS was 5.2 (median 4, range 2-9). Average peri-operative drop in PMS was two points (median 1.5, range 0-6). Of the 11 patients who survived to discharge, 10 were independently mobile and returned to their pre-operation residence. Nine required a change in walking aids. Only one patient reported post-operative pain. This small patient series suggests that the Gamma3 Long Nail is a suitable treatment option for impending and actual metastatic femoral fractures in the District General setting. Length of stay, in-hospital mortality and re-operation rates compare favourably with published data on the Gamma2. There was a significant drop in Parker Mobility Score but all patients bar one were independently mobile and returned to their home. Anaesthetic time was not lower than with the Gamma2, suggesting little tangible benefit of the new instrumentation

Long femoral nails for neck of femur fractures and prophylactic fixation have a risk of anterior cortex perforation. Previous studies have demonstrated the radius of curvature (ROC) of a femoral nail influencing the finishing point of a nail and the risk of anterior cortex perforation. This study aims to calculate a patients femoral ROC using preoperative XR and CT and therefore nail finishing position. We conducted a retrospective study review of patients with long femoral cephalomedullary nailing for proximal femur fractures (OTA/AO 31(A) and OTA/AO 32) or impending pathological fractures at a level 1 trauma centre between January 1, 2015 and December 31, 2020 with both full length lateral X-ray and CT imaging. Femoral ROC was calculated on both imaging modalities. Outcomes measured including nail finishing position, anterior cortex encroachment and impingement. The mean femoral ROC was 1026mm on CT and 1244mm on XR. CT femoral ROC strongly correlated with nail finishing point with a spearmans coefficient of 0.77. Additionally, femurs with a ROC <1000mm were associated with a higher risk of anterior encroachment (OR 6.12) and femurs with a ROC <900mm were associated with a higher risk of anterior cortex impingement (OR 6.47). To our knowledge this is the first study to compare a measured femoral ROC to nail finishing position. The use of CT to measure femoral ROC and to a lesser extent XR was able to predict both nail finishing position and risk of anterior cortex encroachment. Preoperative XRs and CTs were able to identify patients with a small femoral ROC. This predicted patients at risk of anterior cortex impingement, anterior cortex encroachment and nail finishing position. We may be able to select femoral nails that resemble the native femoral ROC and mitigate the risk of anterior cortex perforation

The senior author has treated a series of patients with subtrochanteric and diaphyseal femoral stress fractures associated with long-term alendronate or other bisphosphonate usage. Several patients completely fractured their femurs prior to referral. Most patients had consulted other physicians and were referred for presumed neoplasms. All patients had been diagnosed with osteoporosis and had been treated with bisphosphonates. Their plane radiographs revealed abnormalities that are pathognomonic of bisphosphonate-associated stress fractures. However, due to the subtle nature of these new unfamiliar abnormalities, most were unrecognized as such by clinicians (including experienced ISTA member hip surgeons) and radiologists. This series is presented to illustrate this pattern of impending fracture. The authors have reviewed and will present a series (n=17) of femoral stress fractures in bisphosphonate-treated patients to illustrate the clinical and radiographic pattern of these stress fractures, and review their treatment. The most common lesion is a subtrochanteric lateral cortical thickening that in actuality is a horizontal plane “dreaded black line” of a stress fracture with surrounding proximal and distal cortical thickening of the endosteal and periosteal bone. The stress fracture line is obscured unless a near-perfect radiographic projection is obtained. The lesion is best seen with CT scans. MRI scans reveal the stress fracture lines with surrounding edema (Fig 1), which may be misinterpreted as a tumor. Without treatment, a low-impact completed fracture will likely occur. Many bisphosphonate-associated impending subtrochanteric femoral stress fractures are misdiagnosed as trochanteric bursitis, leading to subsequent displaced subtrochanteric fractures [Fig. 2 - Note subtle impending fracture lesion on right, completed fracture on left]. The clinical and subtle radiographic findings must be recognized by orthopaedic surgeons, particularly hip surgeons, to prevent these complete fractures. These fractures are preventable with internal fixation. Long-term administration of bisphosphonates can have adverse effects, and alternatives to long-term continuous dosing must be investigated to determine optimal administration regimens

Advances in cancer therapy have prolonged patient survival even in the presence of disseminated disease and an increasing number of cancer patients are living with metastatic bone disease (MBD). The proximal femur is the most common long bone involved in MBD and pathologic fractures of the femur are associated with significant morbidity, mortality and loss of quality of life (QoL). Successful prophylactic surgery for an impending fracture of the proximal femur has been shown in multiple cohort studies to result in longer survival, preserved mobility, lower transfusion rates and shorter post-operative hospital stays. However, there is currently no optimal method to predict a pathologic fracture. The most well-known tool is Mirel's criteria, established in 1989 and is limited from guiding clinical practice due to poor specificity and sensitivity. The ideal clinical decision support tool will be of the highest sensitivity and specificity, non-invasive, generalizable to all patients, and not a burden on hospital resources or the patient's time. Our research uses novel machine learning techniques to develop a model to fill this considerable gap in the treatment pathway of MBD of the femur. The goal of our study is to train a convolutional neural network (CNN) to predict fracture risk when metastatic bone disease is present in the proximal femur. Our fracture risk prediction tool was developed by analysis of prospectively collected data of consecutive MBD patients presenting from 2009–2016. Patients with primary bone tumors, pathologic fractures at initial presentation, and hematologic malignancies were excluded. A total of 546 patients comprising 114 pathologic fractures were included. Every patient had at least one Anterior-Posterior X-ray and clinical data including patient demographics, Mirel's criteria, tumor biology, all previous radiation and chemotherapy received, multiple pain and function scores, medications and time to fracture or time to death. We have trained a convolutional neural network (CNN) with AP X-ray images of 546 patients with metastatic bone disease of the proximal femur. The digital X-ray data is converted into a matrix representing the color information at each pixel. Our CNN contains five convolutional layers, a fully connected layers of 512 units and a final output layer. As the information passes through successive levels of the network, higher level features are abstracted from the data. The model converges on two fully connected deep neural network layers that output the risk of fracture. This prediction is compared to the true outcome, and any errors are back-propagated through the network to accordingly adjust the weights between connections, until overall prediction accuracy is optimized. Methods to improve learning included using stochastic gradient descent with a learning rate of 0.01 and a momentum rate of 0.9. We used average classification accuracy and the average F1 score across five test sets to measure model performance. We compute F1 = 2 x (precision x recall)/(precision + recall). F1 is a measure of a model's accuracy in binary classification, in our case, whether a lesion would result in pathologic fracture or not. Our model achieved 88.2% accuracy in predicting fracture risk across five-fold cross validation testing. The F1 statistic is 0.87. This is the first reported application of convolutional neural networks, a machine learning algorithm, to this important Orthopaedic problem. Our neural network model was able to achieve reasonable accuracy in classifying fracture risk of metastatic proximal femur lesions from analysis of X-rays and clinical information. Our future work will aim to externally validate this algorithm on an international cohort

Advances in cancer therapy have prolonged cancer patient survival even in the presence of disseminated disease and an increasing number of cancer patients are living with metastatic bone disease (MBD). The proximal femur is the most common long bone involved in MBD and pathologic fractures of the femur are associated with significant morbidity, mortality and loss of quality of life (QoL). Successful prophylactic surgery for an impending fracture of the proximal femur has been shown in multiple cohort studies to result in patients more likely to walk after surgery, longer survival, lower transfusion rates and shorter post-operative hospital stays. However, there is currently no optimal method to predict a pathologic fracture. The most well-known tool is Mirel's criteria, established in 1989 and is limited from guiding clinical practice due to poor specificity and sensitivity. The goal of our study is to train a convolutional neural network (CNN) to predict fracture risk when metastatic bone disease is present in the proximal femur. Our fracture risk prediction tool was developed by analysis of prospectively collected data for MBD patients (2009–2016) in order to determine which features are most commonly associated with fracture. Patients with primary bone tumors, pathologic fractures at initial presentation, and hematologic malignancies were excluded. A total of 1146 patients comprising 224 pathologic fractures were included. Every patient had at least one Anterior-Posterior X-ray. The clinical data includes patient demographics, tumor biology, all previous radiation and chemotherapy received, multiple pain and function scores, medications and time to fracture or time to death. Each of Mirel's criteria has been further subdivided and recorded for each lesion. We have trained a convolutional neural network (CNN) with X-ray images of 1146 patients with metastatic bone disease of the proximal femur. The digital X-ray data is converted into a matrix representing the color information at each pixel. Our CNN contains five convolutional layers, a fully connected layers of 512 units and a final output layer. As the information passes through successive levels of the network, higher level features are abstracted from the data. This model converges on two fully connected deep neural network layers that output the fracture risk. This prediction is compared to the true outcome, and any errors are back-propagated through the network to accordingly adjust the weights between connections. Methods to improve learning included using stochastic gradient descent with a learning rate of 0.01 and a momentum rate of 0.9. We used average classification accuracy and the average F1 score across test sets to measure model performance. We compute F1 = 2 x (precision x recall)/(precision + recall). F1 is a measure of a test's accuracy in binary classification, in our case, whether a lesion would result in pathologic fracture or not. Five-fold cross validation testing of our fully trained model revealed accurate classification for 88.2% of patients with metastatic bone disease of the proximal femur. The F1 statistic is 0.87. This represents a 24% error reduction from using Mirel's criteria alone to classify the risk of fracture in this cohort. This is the first reported application of convolutional neural networks, a machine learning algorithm, to an important Orthopaedic problem. Our neural network model was able to achieve impressive accuracy in classifying fracture risk of metastatic proximal femur lesions from analysis of X-rays and clinical information. Our future work will aim to validate this algorithm on an external cohort

The orthopaedic surgeon is often consulted to manage pathologic fractures due to metastatic disease, even though he or she may not be an orthopaedic oncologist. A good understanding of the principles of management of metastatic disease is therefore important. The skeleton remains a common site for metastasis, and certain cancers have a predilection for bone, namely, tumors of the breast, prostate, lung, thyroid, and kidney. Myeloma and lymphoma also often involve bone. The proximal femur and pelvis are most commonly affected, so we will focus on those anatomic sites. The patient may present with pain and impending fracture, or with actual fracture. Careful preoperative medical optimization is recommended. If the lesion is solitary, or the primary is unknown, the diagnosis must be made by a full workup and biopsy before definitive treatment is planned. For patients with known metastasis (the most common situation), the options for treatment of pathologic lesions of the proximal femur generally center on internal fixation versus prosthetic replacement. Patients with breast or prostate metastasis can live for several years after pathologic fracture, so constructs must be relatively durable. If fixation is chosen, it must be stable enough to allow full weight bearing, since the overwhelming majority of pathologic fractures will never heal. In general, long constructs are chosen to protect the entire length of the bone. Nails should protect the femoral neck as well, so cephalomedullary devices are typically chosen. Megaprostheses can be useful in situations where bony destruction precludes stable internal fixation. Postoperative radiation is recommended after wound healing. Acetabular involvement typically requires reinforcement rings or cement augmentation with the Harrington technique. Careful multi-disciplinary medical management is recommended to minimise complications

Aims. Bone is a common site of metastatic disease. Skeletal complications include disabling pain and pathological fractures. Palliative surgery for incurable metastatic bone lesions aims to preserve quality of life and function by providing pain relief and stable mobility with fixation or replacement. Current literature has few treatment studies. We present a 5 year longitudinal cohort study of surgery for metastatic bone disease at our large teaching hospital reviewing our complication and mortality rates. Methods. Patients that underwent palliative surgery for metastatic bone lesions were identified from operative records. Demographics, clinical details and outcomes were recorded. Kaplan-Meier analysis was used to calculate survivorship. Results. 43 patients were treated for 44 bone metastases (34 IM Nails, 9 prosthetic replacements, 1 plate). The median age at primary diagnosis was 66 (33–92). Lung cancer was the most common primary. 56% presented with complete fractures and 44% with impending fractures (median Mirel score of 10). Pertrochanteric bone lesions were the most common (74%). Two out of 43 patients died within one day of surgery. 30 day mortality was 12% and 45% at 1 year. In those surviving the 30 day perioperative period, we report a complication rate of 14%. One patient had a dislocated prosthesis. Two patients had delayed or non union and two patients had failure of metalwork. No patient required re operation. Conclusion. Our series observed a 5% fixation failure rate and significant perioperative mortality. Whilst surgery may offer benefit in the non moribund patient with pathological fracture the decision to offer prophylactic surgery is more difficult in light of the high perioperative mortality seen in our study. Indeed, the patients in our study who died within 24 hours of surgery had prophylactic fixations. We conclude that surgical intervention must be carefully considered with realistic expectations of outcomes

INTRODUCTION. The direct anterior approach to THR has become an increasingly popular minimally-invasive technique in an effort to minimize dislocation risk, facility early recovery, and diminish soft tissue injury. However, it has been associated with unique complications including intraoperative femur fracture, cutaneous nerve palsy, stem subsidence, and wound healing complications. These risk of these complications have been documented to be more likely in the surgeon's early experience with the approach. The minimally-invasive Supercapsular Percutaneous-Assisted (SuperPATH) technique was developed to minimize capsular and short-external rotator injury, minimize dislocation risk, and provide an easier transition from the standard posterior approach. METHODS. Fifty (50) consecutive elective total hip replacements in 48 patients were performed using the SuperPATH technique. These also represented the first fifty elective THRs the surgeon performed in practice. Indications were primary or secondary osteoarthritis (92%), avascular necrosis (6%), and impending pathologic fracture (2%). Patients were evaluated retrospectively for dislocation, major, and minor complications. RESULTS. At average follow-up of 10.9 months (Range 1–27 months), there were no dislocation events. There was one periprosthetic fracture identified at 14-day follow-up that required femoral revision surgery in an elderly female patient with osteoporosis. Otherwise, there were no reoperations for any reason. There were no wound complications or deep infections. There was one stem subsidence (2%) of 4 mm. There were no neurovascular injuries. CONCLUSION. The SuperPATH technique can likely be performed at an early experience level with low early complication risk and lower early dislocation risk. This minimally-invasive technique deserves further interest and evaluation as it may present a gentle learning-curve to surgeons

Aims

Restarting planned surgery during the COVID-19 pandemic is a clinical and societal priority, but it is unknown whether it can be done safely and include high-risk or complex cases. We developed a Surgical Prioritization and Allocation Guide (SPAG). Here, we validate its effectiveness and safety in COVID-free sites.

This study was undertaken to evaluate the safety and efficacy of retrievable inferior vena cava filters in high-risk orthopaedic patients. A total of 58 patients had a retrievable inferior vena cava filter placed as an adjunct to chemical and mechanical prophylaxis, most commonly for a history of previous deep-vein thrombosis or pulmonary embolism, polytrauma, or expected prolonged immobilisation. In total 56 patients (96.6%) had an uncomplicated post-operative course. Two patients (3.4%) died in the peri-operative period for unrelated reasons.

Of the 56 surviving patients, 50 (89%) were available for follow-up. A total of 32 filters (64%) were removed without complication at a mean of 37.8 days (4 to 238) after placement. There were four filters (8%) which were retained because of thrombosis at the filter site, and four (8%) were retained because of incorporation of the filter into the wall of the inferior vena cava. In ten cases (20%) the retrievable filter was left in place to continue as primary prophylaxis. No patient had post-removal thromboembolic complications.

A retrievable inferior vena cava filter, as an adjunct to chemical and mechanical prophylaxis, was a safe and effective means of reducing the acute risk of pulmonary embolism in this high-risk group of patients. Although most filters were removed without complications, thereby avoiding the long-term complications that have plagued permanent indwelling filters, a relatively high percentage of filters had to be left in situ.