Insight opinion to surgically treated metastatic bone disease: Scandinavian Sarcoma Group Skeletal Metastasis Registry report of 1195 operated skeletal metastasis

Outcomes Following Pedestal Cup Reconstruction of (Impending) Pathological Fractures of the Acetabulum due to Metastatic Bone Disease

Management of periacetabular metastatic bone disease (MBD) is challenging, specifically if associated with bone loss or fracture. The aim of this study was to evaluate the complications and outcomes after undergoing peri-acetabular reconstruction using an 'ice-cream cone' pedestal cup endoprostheses for the most severe cases of (impending) pathological acetabular fractures. Fifty cases with severe periacetabular disease were identified. Acetabular defects were classified using the Metastatic Acetabular Classification (MAC). Pre- and post-operative mobility was assessed using the Eastern Cooperative Oncology Group (ECOG) Performance Status. Pain levels were assessed using a verbal rating scale. Surgical complications and patient survival were analysed; the Prognostic Immune Nutritional Index (PINI) was applied retrospectively to survival. There were 32 females and 18 males with a median age of 65 (41-88). Median post-operative follow-up was 16 months (IQR 5.5-28.5 months). Thirty-nine had complete, and 11, impending pathological fractures. The observed five-year survival was 19%, with a median survival of 16 months (IQR 5.8-42.5 months). Significantly worse survival was observed with PINI scores < 3.0 (p = 0.003). Excluding three perioperative deaths, 13 complications occurred in 12 patients: Implant failure in six patients (four aseptic loosening, one dislocation and one infection). At the final follow-up, mobility and pain levels were improved in 85% and 100%, respectively. Reconstruction of significant pelvic MBD with the 'ice-cream cone' reduces pain and improves mobility. Whilst the mortality rate is high, it remains a reasonable option for bed-bound, immobile patients. We advocate the use of an 'ice-cream cone' prosthesis for selected patients balancing the reported risks with the observed benefits.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-024-01917-x.

Feasibility of a Novel In-situ Local Tumor Ablation and Recycling Machine Based on Radiofrequency Dielectric Heating: In-depth Review on Research Background and Preliminary Report of an Experimental Study

Background

In bone sarcomas, chemotherapy has improved the prognosis with advances in diagnostic and surgical technologies, which has led to attempts to save limbs. As early detection and multidisciplinary treatment have improved the survival rate, curative surgery is considered for selected patients with metastatic bone carcinomas. Limb salvage procedures may vary in relation to the reconstruction method, which is accompanied by different complications. To overcome them, we devised a novel concept, in-situ local tumor ablation and recycling machine based on radiofrequency (RF)-induced heating and intended experiments to demonstrate its feasibility.

Methods

The fresh femurs of 6-month-old pigs were used after removing the epiphyses; the distal parts were placed in a heating chamber. Fiber-optic temperature sensors were inserted in the metaphysis, meta-diaphysis, and diaphysis. Temperatures were measured six times each during heating at 27.12 MHz at various powers. Additionally, the compressive and bending stiffnesses were measured six times each for the unprocessed, RF-treated, and pasteurized bones, and the results were compared.

Results

Under 200 W power output, the temperatures at all measurement sites reached 70 ℃ or higher in 6 minutes, and the temperatures were maintained. The median compressive stiffness of RF-heated bones was 79.2% higher than that of pasteurized bones, but the difference was statistically insignificant. The median bending stiffness of RF-heated bones was approximately 66.3% of that of unprocessed bones, which was 20% higher than that of pasteurized bones.

Conclusions

The feasibility to rapidly attain and maintain temperatures for tumor ablation is shown, which favorably preserves bone stiffness through the in-situ local tumor ablation and recycling based on RF heating. The problem of nonuniform temperature distribution might be solved by an optimal design determined from simulation research and additional experiments.

Psoas muscle area is an independent survival prognosticator in patients undergoing surgery for long-bone metastases

BACKGROUND

Predictive analytics is gaining popularity as an aid to treatment planning for patients with bone metastases, whose expected survival should be considered. Decreased psoas muscle area (PMA), a morphometric indicator of suboptimal nutritional status, has been associated with mortality in various cancers, but never been integrated into current survival prediction algorithms (SPA) for patients with skeletal metastases. This study investigates whether decreased PMA predicts worse survival in patients with extremity metastases and whether incorporating PMA into three modern SPAs (PATHFx, SORG-NG, and SORG-MLA) improves their performance.

METHODS

One hundred eighty-five patients surgically treated for long-bone metastases between 2014 and 2019 were divided into three PMA tertiles (small, medium, and large) based on their psoas size on CT. Kaplan-Meier, multivariable regression, and Cox proportional hazards analyses were employed to compare survival between tertiles and examine factors associated with mortality. Logistic regression analysis was used to assess whether incorporating adjusted PMA values enhanced the three SPAs' discriminatory abilities. The clinical utility of incorporating PMA into these SPAs was evaluated by decision curve analysis (DCA).

RESULTS

Patients with small PMA had worse 90-day and 1-year survival after surgery (log-rank test p < 0.001). Patients in the large PMA group had a higher chance of surviving 90 days (odds ratio, OR, 3.72, p = 0.02) and 1 year than those in the small PMA group (OR 3.28, p = 0.004). All three SPAs had increased AUC after incorporation of adjusted PMA. DCA indicated increased net benefits at threshold probabilities >0.5 after the addition of adjusted PMA to these SPAs.

CONCLUSIONS

Decreased PMA on CT is associated with worse survival in surgically treated patients with extremity metastases, even after controlling for three contemporary SPAs. Physicians should consider the additional prognostic value of PMA on survival in patients undergoing consideration for operative management due to extremity metastases.

Orthopaedic surgeons' ability to detect pathologic hip fractures: review of 1484 fractures reported to the Norwegian Hip Fracture Register

BACKGROUND

The proximal femur is the most common location of metastases in the appendicular skeleton. Data on pathologic hip fractures, however, are sparse despite it is the most frequently operated pathologic fracture. The aim of this study was to investigate the ability of orthopaedic surgeons to identify pathologic hip fractures in an acute setting and secondly to validate the underlying cause of the pathologic fractures reported to Norwegian Hip Fracture Register (NHFR).

METHODS

In the NHFR dataset between 2005 and 2019, we identified 1484 fractures reported to be pathologic possibly secondary to a malignancy. These fractures were thoroughly validated by reviewing X-rays, the patient journal, the operation description for date, side, why there had been suspicion of pathologic fracture, and implant choice. Pathology reports were reviewed once a biopsy had been performed. Based on this validation, information in the NHFR was corrected, whenever necessary.

RESULTS

Of the 1484 fractures possible secondary to malignancy, 485 (32.7%) were not a pathologic fracture. When reviewing the 999 validated pathologic fractures, 15 patients had a pathologic fracture secondary to a benign lesion. The remaining 984 patients had a pathologic fracture secondary to malignancy. The underlying diagnosis reported was corrected in 442 of the 999 patients. The true rate of pathologic hip fractures secondary to malignancy in our material was 0.8%, and most patients had underlying prostate (30%), breast (20%), or lung (17%) cancer.

CONCLUSION

Orthopaedic surgeons in Norway failed to report correct data on pathologic fractures and the corresponding cancer diagnosis in an acute setting in many patients. The corrected data on pathologic fractures in the NHFR from 2005 to 2019 can now be a valid resource for further studies on the subject.

Development and Validation of a Convolutional Neural Network Model to Predict a Pathologic Fracture in the Proximal Femur Using Abdomen and Pelvis CT Images of Patients With Advanced Cancer

BACKGROUND

Improvement in survival in patients with advanced cancer is accompanied by an increased probability of bone metastasis and related pathologic fractures (especially in the proximal femur). The few systems proposed and used to diagnose impending fractures owing to metastasis and to ultimately prevent future fractures have practical limitations; thus, novel screening tools are essential. A CT scan of the abdomen and pelvis is a standard modality for staging and follow-up in patients with cancer, and radiologic assessments of the proximal femur are possible with CT-based digitally reconstructed radiographs. Deep-learning models, such as convolutional neural networks (CNNs), may be able to predict pathologic fractures from digitally reconstructed radiographs, but to our knowledge, they have not been tested for this application.

QUESTIONS/PURPOSES

(1) How accurate is a CNN model for predicting a pathologic fracture in a proximal femur with metastasis using digitally reconstructed radiographs of the abdomen and pelvis CT images in patients with advanced cancer? (2) Do CNN models perform better than clinicians with varying backgrounds and experience levels in predicting a pathologic fracture on abdomen and pelvis CT images without any knowledge of the patients' histories, except for metastasis in the proximal femur?

METHODS

A total of 392 patients received radiation treatment of the proximal femur at three hospitals from January 2011 to December 2021. The patients had 2945 CT scans of the abdomen and pelvis for systemic evaluation and follow-up in relation to their primary cancer. In 33% of the CT scans (974), it was impossible to identify whether a pathologic fracture developed within 3 months after each CT image was acquired, and these were excluded. Finally, 1971 cases with a mean age of 59 ± 12 years were included in this study. Pathologic fractures developed within 3 months after CT in 3% (60 of 1971) of cases. A total of 47% (936 of 1971) were women. Sixty cases had an established pathologic fracture within 3 months after each CT scan, and another group of 1911 cases had no established pathologic fracture within 3 months after CT scan. The mean age of the cases in the former and latter groups was 64 ± 11 years and 59 ± 12 years, respectively, and 32% (19 of 60) and 53% (1016 of 1911) of cases, respectively, were female. Digitally reconstructed radiographs were generated with perspective projections of three-dimensional CT volumes onto two-dimensional planes. Then, 1557 images from one hospital were used for a training set. To verify that the deep-learning models could consistently operate even in hospitals with a different medical environment, 414 images from other hospitals were used for external validation. The number of images in the groups with and without a pathologic fracture within 3 months after each CT scan increased from 1911 to 22,932 and from 60 to 720, respectively, using data augmentation methods that are known to be an effective way to boost the performance of deep-learning models. Three CNNs (VGG16, ResNet50, and DenseNet121) were fine-tuned using digitally reconstructed radiographs. For performance measures, the area under the receiver operating characteristic curve, accuracy, sensitivity, specificity, precision, and F1 score were determined. The area under the receiver operating characteristic curve was used to evaluate three CNN models mainly, and the optimal accuracy, sensitivity, and specificity were calculated using the Youden J statistic. Accuracy refers to the proportion of fractures in the groups with and without a pathologic fracture within 3 months after each CT scan that were accurately predicted by the CNN model. Sensitivity and specificity represent the proportion of accurately predicted fractures among those with and without a pathologic fracture within 3 months after each CT scan, respectively. Precision is a measure of how few false-positives the model produces. The F1 score is a harmonic mean of sensitivity and precision, which have a tradeoff relationship. Gradient-weighted class activation mapping images were created to check whether the CNN model correctly focused on potential pathologic fracture regions. The CNN model with the best performance was compared with the performance of clinicians.

RESULTS

DenseNet121 showed the best performance in identifying pathologic fractures; the area under the receiver operating characteristic curve for DenseNet121 was larger than those for VGG16 (0.77 ± 0.07 [95% CI 0.75 to 0.79] versus 0.71 ± 0.08 [95% CI 0.69 to 0.73]; p = 0.001) and ResNet50 (0.77 ± 0.07 [95% CI 0.75 to 0.79] versus 0.72 ± 0.09 [95% CI 0.69 to 0.74]; p = 0.001). Specifically, DenseNet121 scored the highest in sensitivity (0.22 ± 0.07 [95% CI 0.20 to 0.24]), precision (0.72 ± 0.19 [95% CI 0.67 to 0.77]), and F1 score (0.34 ± 0.10 [95% CI 0.31 to 0.37]), and it focused accurately on the region with the expected pathologic fracture. Further, DenseNet121 was less likely than clinicians to mispredict cases in which there was no pathologic fracture than cases in which there was a fracture; the performance of DenseNet121 was better than clinician performance in terms of specificity (0.98 ± 0.01 [95% CI 0.98 to 0.99] versus 0.86 ± 0.09 [95% CI 0.81 to 0.91]; p = 0.01), precision (0.72 ± 0.19 [95% CI 0.67 to 0.77] versus 0.11 ± 0.10 [95% CI 0.05 to 0.17]; p = 0.0001), and F1 score (0.34 ± 0.10 [95% CI 0.31 to 0.37] versus 0.17 ± 0.15 [95% CI 0.08 to 0.26]; p = 0.0001).

CONCLUSION

CNN models may be able to accurately predict impending pathologic fractures from digitally reconstructed radiographs of the abdomen and pelvis CT images that clinicians may not anticipate; this can assist medical, radiation, and orthopaedic oncologists clinically. To achieve better performance, ensemble-learning models using knowledge of the patients' histories should be developed and validated. The code for our model is publicly available online at https://github.com/taehoonko/CNN_path_fx_prediction .

LEVEL OF EVIDENCE

Level III, diagnostic study.

The Importance of Awaiting Biopsy Results in Solitary Pathological Proximal Femoral Fractures : Do We Need to Biopsy Solitary Pathological Fractures?

BACKGROUND

The optimal surgical treatment for patients presenting with (impending and complete) pathological proximal femoral fractures is predicated on prognosis. Guidelines recommend a preoperative biopsy to exclude sarcomas, however no evidence confirms a benefit.

OBJECTIVE

This study aimed to describe the diagnostic accuracy, morbidity and sarcoma incidence of biopsy results in these patients.

MATERIAL AND METHODS

All patients (n = 153) presenting with pathological proximal femoral fractures between 2000 and 2019 were retrospectively evaluated. Patients after inadvertent surgery (n = 25) were excluded. Descriptive statistics were used to evaluate the accuracy and morbidity of diagnostic biopsies.

RESULTS

Of 112/128 patients who underwent biopsy, nine (8%) biopsies were unreliable either due to being inconclusive (n = 5) or because the diagnosis changed after resection (n = 4). Of impending fractures, 32% fractured following needle core biopsy. Median time from diagnosis to surgery was 30 days (interquartile range 21-46). The overall biopsy positive predictive value (PPV) to differentiate between sarcoma and non-sarcoma was 1.00 (95% confidence interval [CI] 0.88-1.00). In patients with a previous malignancy (n = 24), biopsy (n = 23) identified the diagnosis in 83% (PPV 0.91, 95% CI 0.71-0.99), of whom five (24%) patients had a new diagnosis. In patients without a history of cancer (n = 61), final diagnosis included carcinomas (n = 24, 39.3%), sarcomas (n = 24, 39.3%), or hematological malignancies (n = 13, 21.3%). Biopsy (n = 58) correctly identified the diagnosis in 66% of patients (PPV 0.80, 95% CI 0.67-0.90).

CONCLUSION

This study confirms the importance of a preoperative biopsy in solitary pathological proximal femoral fractures due to the risk of sarcoma in patients with and without a history of cancer. However, biopsy delays the time to definite surgery, results can be inconclusive or false, and it risks completion of impending fractures.

Intramedullary Nailing with and without the Use of Bone Cement for Impending and Pathologic Fractures of the Humerus in Multiple Myeloma and Metastatic Disease

Although intramedullary nailing (IMN) is considered the standard of care for the surgical management of most femur metastatic diseases, the optimal treatment of metastatic humeral impending and/or pathologic fractures is still debatable. Moreover, the use of cemented humeral nails has not been thoroughly studied, and only a few small series have compared their results with uncemented nails. The purpose of this study was to compare the (1) survivorship, (2) functional outcomes, and (3) perioperative complications in patients receiving cemented versus uncemented humerus IMN for impending or complete pathologic fractures resulting from metastatic disease or multiple myeloma. We retrospectively reviewed 100 IMNs in 82 patients, of which 53 were cemented and 47 were uncemented. With a mean survival of 10 months (Cemented: 8.3 months vs. Uncemented: 11.6 months, p = 0.34), the mean Musculoskeletal Tumor Society (MSTS) scores increased from 42.4% preoperatively (Cemented: 40.2% vs. Uncemented: 66.7%, p = 0.01) to 89.2% at 3 months postoperatively (Cemented: 89.8% vs. Uncemented: 90.9%, p = 0.72) for the overall group (p < 0.001). Both cohorts yielded comparable complication rates (overall [22.6% vs. 19.1%)], surgical ([11.3% vs. 4.3%], and medical [13.2% vs. 14.9%], all p > 0.05), but estimated blood loss was significantly higher in the cemented group (203 mL vs. 126 mL, p = 0.003). Thus, intramedullary nailing, with and without cement augmentation in select patients, is a relatively safe and effective therapeutic modality for metastatic humeral disease with similar clinical outcomes and acceptable complication rates. While controlling for possible selection bias, larger-scale, higher-level studies are warranted to validate our results.

The Role of Post-Operative Radiotherapy for Non-Spine Bone Metastases (NSBMs)

Non-spine bone metastases (NSBMs) can cause significant morbidity and deterioration in the quality of life of cancer patients. This paper reviews the role of post-operative radiotherapy (PORT) in the management of NSBMs and provides suggestions for clinical practice based on the best available evidence. We identified six retrospective studies and several reviews that examined PORT for NSBMs. These studies suggest that PORT reduces local recurrence rates and provides effective pain relief. Based on the literature, PORT was typically delivered as 20 Gy in 5 fractions or 30 Gy in 10 fractions within 5 weeks of surgery. Complete coverage of the surgical hardware is an important consideration when designing an appropriate radiation plan and leads to improved local control. Furthermore, the integration of PORT in a multidisciplinary team with input from radiation oncologists and orthopedic surgeons is beneficial. A multimodal approach including PORT should be considered for an NSBM that requires surgery. However, phase III studies are needed to answer many remaining questions and optimize the management of NSBMs.

Comparison of proximal and distal involvement of upper extremity metastatic lesions: an analysis of 55 cases

We analysed the differences in clinical presentation between proximal (above elbow) and distal (below elbow) upper limb metastases in a retrospective review of patients presenting to our centre from 2011 to 2019. There were 55 cases, 64% involving the humerus and 62% occurring in men. The median age at the time of diagnosis was 64 years. Thirty-one per cent of the cases were proximal lesions. Distal upper limb metastases were more likely to be soft tissue lesions (71%) compared with proximal lesions (8%). The median age of patients with distal lesions was significantly lower at 58 years compared with 65 years for proximal lesions. Overall, non-small cell lung carcinoma was the most common primary malignancy (25%), however haematological cancers were most common in the distal group (29%). Distal upper limb metastases have distinct features that distinguish them from proximal lesions.Level of evidence: IV.

Age, sex, primary tumor type and site are associated with mortality after pathological fractures: an observational study of 1453 patients from the Swedish Fracture Register

BACKGROUND

Pathological fractures are challenging in orthopedic surgery and oncology, with implications for the patient's quality of life, mobility and mortality. The efficacy of oncological treatment on life expectancy for cancer patients has improved, but the metastatic pattern for bone metastases and survival is diverse for different tumor types. This study aimed to evaluate survival in relation to age, sex, primary tumor and site of the pathological fractures.

METHODS

All pathological fractures due to cancer between 1 September 2014 and 31 December 2021 were included in this observational study from the Swedish Fracture Register (SFR). Data on age, sex, tumor type, fracture site and mortality were collected.

RESULTS

A total of 1453 patients with pathological fractures were included (48% women, median age 73, range 18-100 years). Unknown primary tumors were the most common primary site (n = 308). The lower extremities were the most common site of pathological fractures. Lung cancer had the shortest median survival of 78 days (range 54-102), and multiple myeloma had the longest median survival of 432 days (range 232-629). The site at the lower extremity had the shortest (187 days, range 162-212), and the spine had the longest survival (386 days, range 211-561). Age, sex, primary type and site of the pathological fractures were all associated with mortality.

INTERPRETATION

Age, sex, primary tumor type and site of pathological fractures were associated with survival. Survival time is short and correlated with primary tumor type, with lung cancer as the strongest negative predictor of survival.

Fracture risk assessment and evaluation of femoroplasty in metastatic proximal femurs. An in vivo CT-based finite element study

The goal of this study was twofold. First, we aimed to evaluate the accuracy of a finite element (FE) model to predict bone fracture in cancer patients with proximal femoral bone metastases. Second, we evaluated whether femoroplasty could effectively reduce fracture risk. A total of 89 patients were included, with 101 proximal femurs affected with bone metastases. The accuracy of the model to predict fracture was evaluated by comparing the FE failure load, normalized for body weight, against the actual occurrence of fracture during a 6-month follow-up. Using a critical threshold, the model could identify whether femurs underwent fracture with a sensitivity of 92% and a specificity of 66%. A virtual treatment with femoroplasty was simulated in a subset of 34 out of the 101 femurs; only femurs with one or more well-defined lytic lesions were considered eligible for femoroplasty. We modeled their lesions, as well as the surrounding 4 mm of trabecular bone, to be augmented with bone cement. The simulation of femoroplasty increased the median failure load of the FE model by 57% for lesions located in the head/neck of the femur. At this lesion location, all high risk femurs that had fractured during follow-up effectively moved from a failure load below the critical threshold to a value above. For lesions located in the trochanteric region, no definite improvement in failure load was found. Although additional validation studies are required, our results suggest that femoroplasty can effectively reduce fracture risk for several osteolytic lesions in the femoral head/neck.

A machine learning-Based model to predict early death among bone metastatic breast cancer patients: A large cohort of 16,189 patients

Purpose: This study aims to develop a prediction model to categorize the risk of early death among breast cancer patients with bone metastases using machine learning models. Methods: This study examined 16,189 bone metastatic breast cancer patients between 2010 and 2019 from a large oncological database in the United States. The patients were divided into two groups at random in a 90:10 ratio. The majority of patients (n = 14,582, 90%) were served as the training group to train and optimize prediction models, whereas patients in the validation group (n = 1,607, 10%) were utilized to validate the prediction models. Four models were introduced in the study: the logistic regression model, gradient boosting tree model, decision tree model, and random forest model. Results: Early death accounted for 17.4% of all included patients. Multivariate analysis demonstrated that older age; a separated, divorced, or widowed marital status; nonmetropolitan counties; brain metastasis; liver metastasis; lung metastasis; and histologic type of unspecified neoplasms were significantly associated with more early death, whereas a lower grade, a positive estrogen receptor (ER) status, cancer-directed surgery, radiation, and chemotherapy were significantly the protective factors. For the purpose of developing prediction models, the 12 variables were used. Among all the four models, the gradient boosting tree had the greatest AUC [0.829, 95% confident interval (CI): 0.802-0.856], and the random forest (0.828, 95% CI: 0.801-0.855) and logistic regression (0.819, 95% CI: 0.791-0.847) models came in second and third, respectively. The discrimination slopes for the three models were 0.258, 0.223, and 0.240, respectively, and the corresponding accuracy rates were 0.801, 0.770, and 0.762, respectively. The Brier score of gradient boosting tree was the lowest (0.109), followed by the random forest (0.111) and logistic regression (0.112) models. Risk stratification showed that patients in the high-risk group (46.31%) had a greater six-fold chance of early death than those in the low-risk group (7.50%). Conclusion: The gradient boosting tree model demonstrates promising performance with favorable discrimination and calibration in the study, and this model can stratify the risk probability of early death among bone metastatic breast cancer patients.

A Patient-Specific Fracture Risk Assessment Tool for Femoral Bone Metastases: Using the Bone Strength (BOS) Score in Clinical Practice

Patients with femoral metastases are at risk of fracturing bones. It is important to prevent fractures in order to maintain mobility and quality of life. The BOne Strength (BOS) score is based on a computed tomography (CT)-based patient-specific finite element (FE) computer model that objectively calculates bone strength. In this pilot study, the added clinical value of the BOS score towards treatment-related decision making was assessed. In December 2019, the BOS score was implemented in four radiotherapy centers. The BOS scores and fracture risks of individual patients were calculated and returned to the physician to assist in treatment decisions. The physicians filled out a questionnaire, which was qualitatively analyzed. A follow-up to identify fractures and/or death was performed after six months. Until June 2021, 42 BOS scores were delivered (20 high, 9 moderate, and 13 low fracture risk). In 48%, the BOS score led to an adaptation of treatment plans. Physicians indicated that the BOS score provided objective insight into fracture risk, was reassuring for physicians and patients, and improved multidisciplinary discussions and shared decision making. In conclusion, the BOS score is an objective tool to assess fracture risk in femoral bone metastases and aids physicians and patients in making a more informed decision regarding the most appropriate treatment.

The Prediction of Survival after Surgical Management of Bone Metastases of the Extremities—A Comparison of Prognostic Models

Individualized survival prognostic models for symptomatic patients with appendicular metastatic bone disease are key to guiding clinical decision-making for the orthopedic surgeon. Several prognostic models have been developed in recent years; however, most orthopedic surgeons have not incorporated these models into routine practice. This is possibly due to uncertainty concerning their accuracy and the lack of comparison publications and recommendations. Our aim was to conduct a review and quality assessment of these models. A computerized literature search in MEDLINE, EMBASE and PubMed up to February 2022 was done, using keywords: “Bone metastasis”, “survival”, “extremity” and “prognosis”. We evaluated each model’s performance, assessing the estimated discriminative power and calibration accuracy for the analyzed patients. We included 11 studies out of the 1779 citations initially retrieved. The 11 studies included seven different models for estimating survival. Among externally validated survival prediction scores, PATHFx 3.0, 2013-SPRING and potentially Optimodel were found to be the best models in terms of performance. Currently, it is still a challenge to recommend any of the models as the standard for predicting survival for these patients. However, some models show better performance status and other quality characteristics. We recommend future, large, multicenter, prospective studies to compare between PATHfx 3.0, SPRING 2013 and OptiModel using the same external validation dataset.

Surgical treatment of bone metastasis from osteophilic cancer. Results in 401 peripheral and spinal locations

INTRODUCTION

Peripheral and spinal bone metastases arise mainly from 5 osteophilic cancers: lung, prostate, kidney, breast and thyroid. Few studies combined results for the two types metastatic location (peripheral and spinal). Therefore we performed a multicenter retrospective study of surgically managed peripheral and spinal bone metastases to assess: (1) global function at a minimum 1 year's follow-up and; (2) factors affecting survival.

HYPOTHESIS

Global function is improved by surgery, with acceptable survival.

MATERIAL AND METHOD

Between 2015 and 2016, 386 patients were operated on in 11 centers for 401 metastases: 231 peripheral, and 170 spinal. Mean age was 62.6±12.5 years in the 212 female patients (54%) versus 66.4±11.5 years in the 174 males (46%) (p=0.001). Pre- to postoperative comparison was made on pain on VAS (visual analog scale), WHO (World Health Organization) score, Karnofsky score, walking and global upper-limb function. Survival was estimated at 4 years' follow-up.

RESULTS

The most frequent locations were in the femur (n=146, 36%) and thoracic spine (n=107, 27%). The primary cancer was revealed by the metastasis in 82 patients (21%). There were 55 general complications (14%) and 48 local complications (12%). Twenty-one patients (5.4%) died during the first month. VAS and Karnofsky sores improved: respectively, 6.6±2.3 vs. 3.4±2.1 (p<0.001) and 65±14 vs. 72±20 (p=0.01). Walking, upper-limb function and Frankel grade improved in respectively 49/86 (57%), 19/29 (66%) and 31/84 (37%) patients. Median survival was 13.3 months (95% CI: 10.8-17.1), and was related to the primary (log-rank, p<0.001): lung 6.5 months (95% CI: 5.2-8.9), prostate 11.1 months (95% CI: 5.3-43.6), kidney 12.9 months (95% CI: 8.4-22.6), breast 26.5 months (95% CI: 19.0-34.0), and thyroid 49.0 months (95% CI: 12.2-NA). On multivariate analysis, independent factors for death comprised internal fixation rather than prosthesis (OR=2.20; 95% CI: 1.59-3.04 (p<0.001)), high preoperative ASA score (OR=1.78; 95% CI: 1.40-2.28 (p<0.001)), preoperative chemotherapy (OR=1.26; 95% CI: 1.13-1.41 (p<0.001)) and major visceral metastasis (lung, brain, liver) (OR=11.80; 95% CI: 5.21-26.71 (p<0.001)).

CONCLUSION

Although function improved only slightly, pain relief and maintained autonomy suggest enhanced comfort in life, confirming the study hypothesis only partially. Factors affecting survival and clinical results argue for preventive surgery when possible, before general health status deteriorates.

LEVEL OF EVIDENCE

IV; retrospective observational.

Musculoskeletal Metastasis From Soft-tissue Sarcomas: A Review of the Literature

Soft-tissue sarcomas are a rare and extremely heterogeneous group of cancers, representing <1% of all human malignancies. The lungs are the most common site of distant metastasis, followed by the bone, lymph nodes, liver, brain, and subcutaneous tissue. Clinical experience suggests that skeletal metastasis is part of the natural history affecting the prognosis and quality of life in these patients. Approximately 2.2% of patients have skeletal metastasis at diagnosis. However, up to 10% will develop skeletal metastasis after a mean interval of 21.3 months. Although systemic therapy with conventional chemotherapy remains the primary treatment modality for those with metastatic sarcoma, increased survival has been achieved in selected patients who receive multimodality therapy, including surgery, for their metastatic disease. The 5-year overall survival of patients with isolated bone metastases was 41.2% (26.9% to 54.9%), which decreased to 32.9% (21.2% to 45.1%) in the setting of combined bone and lung metastases. Moreover, the resection of the primary soft-tissue sarcoma is a predictor of survival, resulting in a 58% decrease in mortality after surgery (hazard ratio, 0.42, P = 0.013). Understanding the effect of these metastases on patient survival may influence imaging, surveillance, and treatment decisions.

Experimental validation of a voxel-based finite element model simulating femoroplasty of lytic lesions in the proximal femur

Femoroplasty is a procedure where bone cement is injected percutaneously into a weakened proximal femur. Uncertainty exists whether femoroplasty provides sufficient mechanical strengthening to prevent fractures in patients with femoral bone metastases. Finite element models are promising tools to evaluate the mechanical effectiveness of femoroplasty, but a thorough validation is required. This study validated a voxel-based finite element model against experimental data from eight pairs of human cadaver femurs with artificial metastatic lesions. One femur from each pair was left untreated, while the contralateral femur was augmented with bone cement. Finite element models accurately predicted the femoral strength in the defect (R² = 0.96) and augmented (R² = 0.93) femurs. The modelled surface strain distributions showed a good qualitative match with results from digital image correlation; yet, quantitatively, only moderate correlation coefficients were found for the defect (mean R² = 0.78) and augmented (mean R² = 0.76) femurs. This was attributed to the presence of vessel holes in the femurs and the jagged surface representation of our voxel-based models. Despite some inaccuracies in the surface measurements, the FE models accurately predicted the global bone strength and qualitative deformation behavior, both before and after femoroplasty. Hence, they can offer a useful biomechanical tool to assist clinicians in assessing the need for prophylactic augmentation in patients with metastatic bone disease, as well as in identifying suitable patients for femoroplasty.

Outcomes and prognostic factors after surgery for bone metastases in the extremities and pelvis: A retrospective analysis of 140 patients

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Pathological fracture, visceral metastasis and lung cancer were negative prognostic factors for patients with bone metastases in the extremities and pelvis.

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Complications occurred in every fourth patient within the first 30 postoperative days.

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No significant differences in short- and long-term outcomes were observed between endoprosthetic replacement and internal fixation.

Background

Methods

Results

Conclusions

Surgical Treatment of Metastatic Bone Disease in the Appendicular Skeleton: A Population-Based Study

Background: Population-based studies of patients with bone metastases in the appendicular skeleton (aBM) requiring surgery for complete or impending fracture are rare. In this epidemiologically-based observational study we created a large population-based cohort of patients treated for aBM, aiming to: (1) monitor possible time-related changes of the incidence of surgical treatment of aBM-lesions, (2) examine differences in the population and care of patients treated at different treatment centers and (3) examine if findings from a previous pilot study regarding absence of a suitable biopsy of the lesions representing debut of cancer or a relapse has improved the awareness of aBM and hereby increased the focus on regular tumor biopsies and follow-up imaging of cancer patients. Methods: We examined a population-based cohort consisting of all patients treated for aBM 2014−2019. Procedures were performed at five secondary surgical centers (SSC) or one tertiary referral Musculoskeletal Tumor Center (MTC). Patients were followed until end of study (30 September 2021) or death. No patients were lost to follow-up. Results: Four-hundred-fifty-seven patients (493 primary aBM-lesions, 482 procedures) were included. Annual incidence of aBM-surgery was 46 aBM-lesions/million. MTC-patients had a significant better preoperative status than SSC-patients considering factors known for survival. Patients with complete fracture experienced longer surgical delay when treated at MTC compared to SSC: 4 (1−9) and 1 (1−3) days (p < 0.001), respectively. Overall survival for the entire cohort was 37% and 11% at 1 and 5 years (MTC and SSC 1 and 5 year respectively: 44% and 15% vs. 29% and 5%, p < 0.001). In patients with debut or relapse of cancer, 8% and 9% had insufficient biopsies, and 21% and 12% had no biopsy, respectively. Comparison showed no change over time. Conclusions: The current study highlights the low awareness on treating aBM at SSC and emphasizes the importance of caution in interpretation of studies not representing an entire population, thus introducing selection bias.

International Validation of the SORG Machine-learning Algorithm for Predicting the Survival of Patients with Extremity Metastases Undergoing Surgical Treatment

BACKGROUND

The Skeletal Oncology Research Group machine-learning algorithms (SORG-MLAs) estimate 90-day and 1-year survival in patients with long-bone metastases undergoing surgical treatment and have demonstrated good discriminatory ability on internal validation. However, the performance of a prediction model could potentially vary by race or region, and the SORG-MLA must be externally validated in an Asian cohort. Furthermore, the authors of the original developmental study did not consider the Eastern Cooperative Oncology Group (ECOG) performance status, a survival prognosticator repeatedly validated in other studies, in their algorithms because of missing data.

QUESTIONS/PURPOSES

(1) Is the SORG-MLA generalizable to Taiwanese patients for predicting 90-day and 1-year mortality? (2) Is the ECOG score an independent factor associated with 90-day and 1-year mortality while controlling for SORG-MLA predictions?

METHODS

All 356 patients who underwent surgery for long-bone metastases between 2014 and 2019 at one tertiary care center in Taiwan were included. Ninety-eight percent (349 of 356) of patients were of Han Chinese descent. The median (range) patient age was 61 years (25 to 95), 52% (184 of 356) were women, and the median BMI was 23 kg/m2 (13 to 39 kg/m2). The most common primary tumors were lung cancer (33% [116 of 356]) and breast cancer (16% [58 of 356]). Fifty-five percent (195 of 356) of patients presented with a complete pathologic fracture. Intramedullary nailing was the most commonly performed type of surgery (59% [210 of 356]), followed by plate screw fixation (23% [81 of 356]) and endoprosthetic reconstruction (18% [65 of 356]). Six patients were lost to follow-up within 90 days; 30 were lost to follow-up within 1 year. Eighty-five percent (301 of 356) of patients were followed until death or for at least 2 years. Survival was 82% (287 of 350) at 90 days and 49% (159 of 326) at 1 year. The model's performance metrics included discrimination (concordance index [c-index]), calibration (intercept and slope), and Brier score. In general, a c-index of 0.5 indicates random guess and a c-index of 0.8 denotes excellent discrimination. Calibration refers to the agreement between the predicted outcomes and the actual outcomes, with a perfect calibration having an intercept of 0 and a slope of 1. The Brier score of a prediction model must be compared with and ideally should be smaller than the score of the null model. A decision curve analysis was then performed for the 90-day and 1-year prediction models to evaluate their net benefit across a range of different threshold probabilities. A multivariate logistic regression analysis was used to evaluate whether the ECOG score was an independent prognosticator while controlling for the SORG-MLA's predictions. We did not perform retraining/recalibration because we were not trying to update the SORG-MLA algorithm in this study.

RESULTS

The SORG-MLA had good discriminatory ability at both timepoints, with a c-index of 0.80 (95% confidence interval 0.74 to 0.86) for 90-day survival prediction and a c-index of 0.84 (95% CI 0.80 to 0.89) for 1-year survival prediction. However, the calibration analysis showed that the SORG-MLAs tended to underestimate Taiwanese patients' survival (90-day survival prediction: calibration intercept 0.78 [95% CI 0.46 to 1.10], calibration slope 0.74 [95% CI 0.53 to 0.96]; 1-year survival prediction: calibration intercept 0.75 [95% CI 0.49 to 1.00], calibration slope 1.22 [95% CI 0.95 to 1.49]). The Brier score of the 90-day and 1-year SORG-MLA prediction models was lower than their respective null model (0.12 versus 0.16 for 90-day prediction; 0.16 versus 0.25 for 1-year prediction), indicating good overall performance of SORG-MLAs at these two timepoints. Decision curve analysis showed SORG-MLAs provided net benefits when threshold probabilities ranged from 0.40 to 0.95 for 90-day survival prediction and from 0.15 to 1.0 for 1-year prediction. The ECOG score was an independent factor associated with 90-day mortality (odds ratio 1.94 [95% CI 1.01 to 3.73]) but not 1-year mortality (OR 1.07 [95% CI 0.53 to 2.17]) after controlling for SORG-MLA predictions for 90-day and 1-year survival, respectively.

CONCLUSION

SORG-MLAs retained good discriminatory ability in Taiwanese patients with long-bone metastases, although their actual survival time was slightly underestimated. More international validation and incremental value studies that address factors such as the ECOG score are warranted to refine the algorithms, which can be freely accessed online at https://sorg-apps.shinyapps.io/extremitymetssurvival/.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Does surgical technique influence the burden of lung metastases in patients with pathologic long bone fractures?

BACKGROUND

The aims of this study are to (1) determine whether fixation of metastatic long bone fractures with an intramedullary nail (IMN) influences the incidence of lung metastasis in comparison to arthroplasty or ORIF (Arthro/ORIF); and (2) assess this relationship in primary tumor types; and (3) to assess survival implications of lung metastasis after surgery.

METHODS

Retrospective cohort study investigating 184 patients (107 IMN, and 77 Arthro/ORIF) surgically treated for metastatic long bone fractures. Patients were required to have a single surgically treated impending or established pathologic fracture of a long bone, pre-operative lung imaging (lung radiograph or computed tomography) and post-operative lung imaging within 6 months of surgery. Primary cancer types included were breast (n = 70), lung (n = 43), prostate (n = 34), renal cell (n = 37). Statistical analyses were conducted using two-tailed Fisher's exact tests, and Kaplan-Meier survival analyses.

RESULTS

Patients treated with IMN and Arthro/ORIF developed new or progressive lung metastases following surgery at an incidence of 34 and 26%, respectively. Surgical method did not significantly influence lung metastasis (p = 0.33). Furthermore, an analysis of primary cancer subgroups did not yield any differences between IMN vs Arthro/ORIF. Median survival for the entire cohort was 11 months and 1-year overall survival was 42.7% (95% CI: 35.4-49.8). Regardless of fixation method, the presence of new or progressive lung metastatic disease at follow up imaging study was found to have a negative impact on patient survival (p < 0.001).

CONCLUSIONS

In this study, development or progression of metastatic lung disease was not affected by long bone stabilization strategy. IM manipulation of metastatic long bone fractures therefore may not result in a clinically relevant increase in metastatic lung burden. The results of this study also suggest that lung metastasis within 6 months of surgery for metastatic long bone lesions is negatively associated with patient survival.

LEVEL OF EVIDENCE

III, therapeutic study.

Body composition predictors of mortality in patients undergoing surgery for long bone metastases

Background and Objectives

Body composition measurements using computed tomography (CT) may serve as imaging biomarkers of survival in patients with and without cancer. This study assesses whether body composition measurements obtained on abdominal CTs are independently associated with 90‐day and 1‐year mortality in patients with long‐bone metastases undergoing surgery.

Methods

This single institutional retrospective study included 212 patients who had undergone surgery for long‐bone metastases and had a CT of the abdomen within 90 days before surgery. Quantification of cross‐sectional areas (CSA) and CT attenuation of abdominal subcutaneous adipose tissue, visceral adipose tissue, and paraspinous and abdominal muscles were performed at L4. Multivariate Cox proportional‐hazards analyses were performed.

Results

Sarcopenia was independently associated with 90‐day mortality (hazard ratio [HR] = 1.87; 95% confidence interval [CI] = 1.11–3.16; p = 0.019) and 1‐year mortality (HR = 1.50; 95% CI = 1.02–2.19; p = 0.038) in multivariate analysis while controlling for clinical variables such as primary tumors, comorbidities, and chemotherapy. Abdominal fat CSAs and muscle attenuation were not associated with mortality.

Conclusions

The presence of sarcopenia assessed by CT is predictive of 90‐day and 1‐year mortality in patients undergoing surgery for long‐bone metastases. This body composition measurement can be used as novel imaging biomarker supplementing existing prognostic tools to optimize patient selection for surgery and improve shared decision making.

[Surgical treatment of patients with chest wall metastases]

OBJECTIVE

To evaluate postoperative outcomes in patients with chest wall metastases.

MATERIAL AND METHODS

We analyzed 40 patients who underwent surgery for chest wall metastatic lesions. Fourteen (35%) patients had sternal lesion, 26 (65%) ones - rib metastases. We used implants for chest wall defect closure in 15 (37.5%) patients. Chest wall repair with autologous tissues was performed in 19 (47.5%) patients.

RESULTS

Median survival was 17 months. Most patients (n=30, 75%) showed improvement in the quality of life according to Karnofsky and EGOG scale after surgery. Continued tumor growth occurred in 4 (10%) patients within 8-16 months after surgery. There were 2 patients who suffered from tumor recurrence accompanied by other metastatic foci (progression). Complications were diagnosed in 5 (12.5%) patients. Tactical errors were identified in 4 (10%) patients and they were associated with progression of cancer in the form of new metastatic foci within 6 months after surgery.

CONCLUSION

Active surgical approach for bone metastases in patients with favorable cancer-related prognosis can improve quality of life and survival at least in case of solitary lesions. New program for treatment strategy selection based on prognosis of life expectancy and algorithms of surgical treatment will reduce the risk of erroneous management and increase its effectiveness.

Development of a scoring system for survival following surgery for metastatic bone disease

AIMS

The incidence of bone metastases is between 20% to 75% depending on the type of cancer. As treatment improves, the number of patients who need surgical intervention is increasing. Identifying patients with a shorter life expectancy would allow surgical intervention with more durable reconstructions to be targeted to those most likely to benefit. While previous scoring systems have focused on surgical and oncological factors, there is a need to consider comorbidities and the physiological state of the patient, as these will also affect outcome. The primary aim of this study was to create a scoring system to estimate survival time in patients with bony metastases and to determine which factors may adversely affect this.

METHODS

This was a retrospective study which included all patients who had presented for surgery with metastatic bone disease. The data collected included patient, surgical, and oncological variables. Univariable and multivariable analysis identified which factors were associated with a survival time of less than six months and less than one year. A model to predict survival based on these factors was developed using Cox regression.

RESULTS

A total of 164 patients were included with a median survival time of 1.6 years (interquartile range 0.5 to 3.1) after surgery. On multivariable analysis, a higher American Society of Anesthesiologists grade (p < 0.001), a high white cell count (p = 0.002), hyponatraemia (p = 0.001), a preoperative resting heart rate of > 100 bpm (p = 0.052), and the type of primary cancer (p = 0.026) remained significant predictors of reduced survival time. The predictive model developed showed good discrimination and calibration to predict both six- and 12-month survival in patients with metastatic bone disease.

CONCLUSION

In addition to surgical and oncological factors, the level of comorbidity and physiological state of the patient has a significant impact on survival in patients with metastatic bone disease. These factors should be considered when assessing the appropriateness of surgical intervention. This is the first study to examine other patient factors alongside surgical and oncological data to identify a relationship between these and survival. Cite this article: Bone Joint J 2021;103-B(11):1725-1730.

Longitudinal survival trends of patients with cancer with surgically managed appendicular metastatic bone disease: systematic review

BACKGROUND

Advances in systemic cancer therapies have improved survival for patients with metastatic carcinoma; however, it is unknown whether these advances have translated to improved survival for patients with appendicular metastatic bone disease (A-MBD) after orthopedic interventions. We conducted a study to evaluate the trend in overall survival for patients who underwent orthopedic surgery for A-MBD between 1968 and 2018.

METHODS

A systematic search of Embase and Medline to identify studies published since 1968 evaluating patients treated with orthopedic surgery for A-MBD was conducted for a previously published scoping review. We used a meta-regression model to assess the longitudinal trends in 1-, 2- and 5-year overall survival between 1968 and 2018. The midpoint year of patient inclusion for each study was used for analysis. We categorized primary tumour types into a tumour severity score according to prognosis for a further meta-regression analysis.

RESULTS

Of the 5747 studies identified, 103 were retained for analysis. Meta-regression analysis showed no significant effect of midpoint study year on survival across all time points. There was no effect of the weighted average of tumour severity scores for each study on 1-year survival over time.

CONCLUSION

There was no significant improvement in overall survival between 1968 and 2018 for patients with A-MBD who underwent orthopedic surgery. Orthopedic intervention remains a poor prognostic variable for patients with MBD. This finding highlights the need for improved collection of prospective data in this population to identify patients with favourable survival outcomes who may benefit from personalized oncologic surgical interventions.

Comparison between different prognostic models to be used for metastatic bone disease on appendicular skeleton in a Chilean population

PURPOSE

Several preoperation prognosis models used on the treatment of metastatic bone disease on appendicular skeleton have been devised. The purpose of this study was to compare the performance of different survival prognostic models on patients with metastatic bone disease in long bones in a Chilean population.

METHODS

This is a multicentric retrospective study. We retrospectively reviewed the medical records of 136 patients who were confirmed with metastatic bone disease of the appendicular skeleton and who were treated surgically from 2016 to 2019. The minimum follow-up time was 12 months. All patients were assessed using four appendicular metastatic bone disease scoring systems. A preoperative predicted survival time for all 136 patients was retrospectively calculated making use of the revised Katagiri, PathFx, Optimodel and IOR score model.

RESULTS

The PathFx model demonstrated an accuracy at predicting 3 (area under the curve [AUC] = 0.61) and 6-month (AUC = 0.65) survival time after surgical management. IOR score model demonstrated an accuracy at predicting 12-month survival time (AUC = 0.64). The survival rate reached the 44% in a year. The median survival time to death or last follow-up time was 14.9 months (SD ± 15).

CONCLUSION

PathFx score model demonstrated the highest accuracy at predicting a survival time of 3 and 6 months. IOR score model was the most accurate measure at predicting a survival time of 12-months. To our knowledge, this is the first study reporting a comparative analysis of metastatic bone disease with predicting models in a country located in Latin America. PathFx's and IOR score models are the ones to be used in the Chilean population as the predictive models in metastatic bone disease of the appendicular skeleton.

The Surgical Management of Proximal Femoral Metastases: A Narrative Review

The proximal femur is a common location for the development of bony metastatic disease. Metastatic bone disease in this location can cause debilitating pain, pathologic fractures, reduced quality of life, anemia or hypercalcemia. A thorough history, physical examination and preoperative investigations are required to ensure accurate diagnosis and prognosis. The goals of surgical management is to provide pain relief and return to function with a construct that provides stability to allow for immediate weightbearing. Current surgical treatment options include intramedullary nailing, hemiarthroplasty or total hip arthroplasty and endoprosthetic reconstructions. Oligometastatic renal cell carcinoma must be given special consideration as tumor resection and reconstruction has survival benefit. Both tumor and patient characteristics must be taken into account before deciding on the appropriate surgical intervention.

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.

Morbidity and mortality of surgically treated pathologic humerus fractures compared to native humerus fractures

BACKGROUND

Despite an increasing prevalence of patients sustaining pathologic fractures of neoplastic origin, few studies have investigated 30-day postoperative complication profiles after surgical treatment of pathologic humerus fractures. The purposes of this study were to use a large nationally representative database to determine short-term complication profiles after surgical treatment of pathologic humerus fractures and assess how these complications compared with more commonly studied native humerus fractures.

METHODS

Using the National Surgical Quality Improvement Program database, we identified 30,866 patients who underwent surgical treatment for either pathologic (n = 449) or native humerus fractures (n = 30,417) from 2007 to 2017. Thirty-day postoperative complication profiles were ascertained and compared between the 2 groups using χ² analyses. Three logistic regression models were then performed to determine which complications were primarily attributable to the pathologic fracture itself vs. the increased comorbidity burden faced by these patients.

RESULTS

Patients with pathologic humerus fractures experienced significantly higher rates of death (6.0% vs. 0.3%, P < .001), serious adverse events (12.2% vs. 3.7%, P < .001), minor complications (15.8% vs. 4.8%, P < .001), extended postoperative lengths of stay (42.3% vs. 21.3%, P < .001), discharge to facilities (22.3% vs. 13.5%, P < .001), and readmissions (14.8% vs. 3.4%, P < .001) compared with patients with native humerus fractures. With respect to specific complications, patients with pathologic fractures were at significantly higher risk of pulmonary complications (1.3% vs. 0.3%, P < .001), renal complications (0.7% vs. 0.2%, P = .007), thromboembolic complications (1.6% vs. 0.6%, P = .01), and transfusions (15.1% vs. 4.1%, P < .001).

CONCLUSION

After surgical treatment, patients with pathologic humerus fractures had significantly higher complication rates compared with native humerus fractures, suggesting that guidelines and treatment algorithms for native humerus fractures may not be generalizable for those of pathologic origin. These findings have significant implications for preoperative patient counseling and may be used to negotiate higher reimbursement rates for these patients given a significantly higher morbidity and mortality than was previously described in literature. Postoperatively, orthopedic surgeons should closely monitor patients with pathologic humerus fractures for deep vein thrombosis, renal complications, and pulmonary complications, use blood-sparing techniques, and employ a multidisciplinary approach to help manage and prevent a more heterogeneous profile of postsurgical complications.

Fracture Risk of Long Bone Metastases: A Review of Current and New Decision-Making Tools for Prophylactic Surgery

Simple Summary

Long bone metastases are frequently a pivotal point in the oncological history of patients. Weakening of the bone results in pathologic fractures that not only compromise patient function but also their survival. Therefore, the main issue for tumor boards remains timely assessment of the risk of fracture, as this is a key consideration in providing preventive surgery while also avoiding overtreatment. As the Mirels scoring system takes into account both the radiological and the clinical criteria, it has been used worldwide since the 1990s. However, due to increasing concern regarding the lack of accuracy, new thresholds have been defined for the identification of impending fractures that require prophylactic surgery, on the basis of axial cortical involvement and biomechanical models involving quantitative computed tomography. The aim of this review is to establish a state-of-the-art of the risk assessment of long bone metastases fractures, from simple radiologic scores to more complex multidimensional bone models, in order to define new decision-making tools.

Abstract

Long bone pathological fractures very much reflect bone metastases morbidity in many types of cancer. Bearing in mind that they not only compromise patient function but also survival, identifying impending fractures before the actual event is one of the main concerns for tumor boards. Indeed, timely prophylactic surgery has been demonstrated to increase patient quality of life as well as survival. However, early surgery for long bone metastases remains controversial as the current fracture risk assessment tools lack accuracy. This review first focuses on the gold standard Mirels rating system. It then explores other unique imaging thresholds such as axial or circumferential cortical involvement and the merits of nuclear imaging tools. To overcome the lack of specificity, other fracture prediction strategies have focused on biomechanical models based on quantitative computed tomography (CT): computed tomography rigidity analysis (CT-RA) and finite element analysis (CT-FEA). Despite their higher specificities in impending fracture assessment, their limited availability, along with a need for standardization, have limited their use in everyday practice. Currently, the prediction of long bone pathologic fractures is a multifactorial process. In this regard, machine learning could potentially be of value by taking into account clinical survival prediction as well as clinical and improved CT-RA/FEA data.

Emerging Concepts in the Surgical Management of Peri-Acetabular Metastatic Bone Disease

The pelvis is a common site of metastatic bone disease. Peri-acetabular lesions are particularly challenging and can cause severe pain, disability and pathologic fractures. Surgical management of these lesions has historically consisted of cementoplasty for contained lesions and Harrington reconstructions for larger, more destructive lesions. Due to the limitations of these procedures, a number of novel procedures have been developed to manage this challenging problem. Percutaneous techniques—including acetabular screw fixation and cementoplasty augmented with screws—have been developed to minimize surgical morbidity. Recent literature has demonstrated a reliable reduction in pain and improvement in function in appropriately selected patients. Several adjuncts to the Harrington procedure have been utilized in recent years to reduce complication rates. The use of constrained liners and dual mobility bearings have reduced the historically high dislocation rates. Cage constructs and porous tantalum implants are becoming increasingly common in the management of large bony defects and destructive lesions. With novel and evolving surgical techniques, surgeons are presented with a variety of surgical options to manage this challenging condition. Physicians must take into account the patients’ overall health status, oncologic prognosis and anatomic location and extent of disease when developing an appropriate surgical plan.

Metastatic bone disease: new quality performance indicator development

OBJECTIVES

Patients with metastatic bone disease (MBD) should receive the same standard of care regardless of which centre they are treated in. The aim was to develop and test a set of quality performance indicators (QPIs) to evaluate care for patients with MBD referred to orthopaedics.

METHODS

QPIs were adapted from the literature and ranked on feasibility and necessity during a modified RAND/Delphi consensus process. They were then validated and field tested in a retrospective cohort of 108 patients using indicator-specific targets set during consensus.

RESULTS

2568 articles including six guidelines were reviewed. 43 quality objectives were extracted and 40 proceeded to expert consensus. After two rounds, 18 QPIs for MBD care were generated, with the following generating the highest consensus: 'Patients with high fracture risk should receive urgent assessment' (combined mean 6.7/7, 95% CI 6.5 to 6.8) and 'preoperative workup should include full blood tests including group and save' (combined mean 6.7/7, 95% CI 6.5 to 6.9). In the pilot test, targets were met for 5/18 QPIs (mean 52%, standard deviation 22%). The median deviation from projected target was -14% (interquartile range -11% to -31%, range -74% to 11%). The highest scoring QPI was 'adults with fractures should have surgery within 7 days' (target 80%:actual 92%).

CONCLUSIONS

The published evidence and guidelines were adapted into a set of validated QPIs for MBD care which can be used to evaluate variation in care between centres. These QPIs should be correlated with outcome scores to determine whether they can act as predictors of outcome after surgery.

Surgical treatment of skeletal metastases in proximal tibia: a multicenter case series of 74 patients

Background and purpose - The proximal tibia is a rare site for metastatic bone disease and is a challenging anatomical site to manage due to the proximity to the knee joint and poor soft tissue envelope. We investigated implant survival and complications of different surgical strategies in the treatment of proximal tibia pathological fractures.Patients and methods - The study comprised a 4 medical center, retrospective analysis of 74 patients surgically treated for metastases of the proximal tibia. Patient records were reviewed to identify outcome, incidence, and type of complications as well as contributing factors.Results - Reconstruction techniques comprised cement-augmented osteosynthesis (n = 33), tumor prosthesis (n = 31), and total knee arthroplasty with long cemented stems (n = 10). Overall implant survival was 88% at 6 months and 1 year, and 67% at 3 years. After stratification by technique, the implant survival was 82% and 71% at 1 and 3 years with tumor prosthesis, 100% at 1 and 3 years with total knee arthroplasty, and 91% at 1 year and 47% at 3 years with osteosynthesis. Preoperative radiotherapy decreased implant survival. Complications were observed in 19/74 patients. Treatment complications led to amputation in 5 patients.Interpretation - In this study, the best results were seen with both types of prothesis reconstructions, with good implant survival, when compared with treatment with osteosynthesis. However, patients treated with tumor prosthesis showed an increased incidence of postoperative infection, which resulted in poor implant survival. Osteosynthesis with cement is a good alternative for patients with short expected survival whereas endoprosthetic replacement achieved good medium-term results.

Patient-reported assessment of outcome after surgery for bone metastases

Regardless of prognosis, surgery is often considered in metastatic bone disease (MBD) as a palliative procedure to improve function and quality of life. Traditional focus on objective outcomes such as mortality is inappropriate in this group, and there is a drive to assess outcomes via patient-reported outcome measures (PROMs). This is an overview of current understanding of MBD outcomes and how this should influence future decision-making and research. The objectives of this review were to identify difficulties in measuring PROMs in the MBD patient population and explore alternatives to patientreported outcomes. We also provide an overview of current understanding of outcomes in MBD and how this should influence decision-making and direct research.

MRI-Guided Focused Ultrasound of Osseous Metastases: Treatment Parameters Associated With Successful Pain Reduction

BACKGROUND

A phase 3 multicenter trial demonstrated that magnetic resonance imaging (MRI)-guided focused ultrasound (US) is a safe, noninvasive treatment that alleviated pain from bone metastases. However, outcomes varied among institutions (from 0%-100% treatment success).

PURPOSE

The aim of this study was to identify patient selection, technical treatment, and imaging parameters that predict successful pain relief of osseous metastases after MRI-guided focused US.

MATERIALS AND METHODS

This was a secondary analysis of a phase 3 clinical study that included participants who received MRI-guided focused US treatment for painful osseous metastases. Noncontrast CT was obtained before treatment. T2-weighted and T1-weighted postcontrast MRIs at 1.5 T or 3 T were obtained before, at the time of, and at 3 months after treatment. Numerical Rating Scale pain scores and morphine equivalent daily dose data were obtained over a 3-month follow-up period. At the 3-month endpoint, participants were categorized as pain relief responders or nonresponders based on Numerical Rating Scale and morphine equivalent daily dose data. Demographics, technical parameters, and imaging features associated with pain relief were determined using stepwise univariable and multivariable models. Responder rates between the subgroup of participants with all predictive parameters and that with none of the parameters were compared using Fisher exact test.

RESULTS

The analysis included 99 participants (mean age, 59 ± 14 years; 56 women). The 3 variables that predicted successful pain relief were energy density on the bone surface (EDBS) (P = 0.001), the presence of postprocedural periosteal devascularization (black band, BB+) (P = 0.005), and female sex (P = 0.02). The subgroup of participants with BB+ and EDBS greater than 5 J/mm2 had a larger decrease in mean pain score (5.2; 95% confidence interval, 4.6-5.8) compared with those without (BB-, EDBS ≤ 5 J/mm2) (1.1; 95% confidence interval, 0.8-3.0; P < 0.001). Participants with all 3 predictive variables had a pain relief responder rate of 93% compared with 0% in participants having none of the predictive variables (P < 0.001).

CONCLUSIONS

High EDBS during treatment, postprocedural periosteal devascularization around the tumor site (BB+), and female sex increased the likelihood of pain relief after MRI-guided focused US of osseous metastasis.

Surgical outcomes of metastatic bone tumors in the extremities (Surgical outcomes of bone metastases)

•

Prognostic factors: primary tumor, visceral metastases, and surgical procedure.

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PS, BI, EQ-5D, and NRS improved at 3 months after surgery.

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The improvements of PS, BI, EQ-5D, and NRS were maintained for 6 M after surgery.

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The management of bone metastases must be decided by a multidisciplinary team.

•

The proper management of bone metastasis will reduce postoperative complications.

Background

Skeletal related events due to metastatic bone tumors markedly affect the activities of daily living (ADL) and quality of life (QOL) in cancer patients. We focused on multidisciplinary therapy for metastatic bone tumors. This study aimed to evaluate the outcomes of surgical treatment for metastatic bone tumors in the extremities.

Methods

We retrospectively reviewed 114 patients who underwent surgical treatment for metastatic bone tumors of the extremities between 2008 and 2019 and 69 patients were reassessed for more than 6 months after surgery. The most common primary tumor was renal, followed by lung, thyroid, and breast cancers. We assessed 69 patients’ performance status (PS), Barthel Index (BI) for ADL, EuroQol 5 Dimensions (EQ-5D) for QOL, and numerical rating scale (NRS) for pain and analyzed these postoperative values relative to preoperative values using Friedman’s test. The postoperative overall survival and the prognostic factors were evaluated using the Kaplan-Meier method, the log-rank test and Cox proportional hazards analysis.

Results

The 1-year overall survival rate was 59%, and the median survival time after surgery was 20 months. Primary tumor, visceral metastasis, and surgical procedure were risk factors correlated with overall survival. PS, BI, EQ-5D, and NRS improved at 3 months after surgery and these improvements were maintained for 6 months after surgery regardless of the surgical procedure.

Conclusions

The significant factors affecting survival after surgical treatment for bone metastases included the primary tumor, presence of visceral metastases, and internal fixation without tumor resection or curettage. Surgical treatment for metastatic bone tumors effectively reduced pain and improved PS, ADL, and QOL postoperatively after 3 months.

Harrington rods for periacetabular pathological lesion: is it an option?

Advancement in cancer treatment has prolonged the survival of cancer patients; as a result, there are an increased number of patients with bone metastases and pathological fractures referred to orthopaedic surgeons for surgical intervention for a better quality of life. Metastasis around the hip joint can be painful and intervene with patients' daily activity, and reconstruction of the hip joint with periacetabular metastasis is complex and challenging especially longer cancer survivals might out-live their fixation. Several acetabular reconstruction techniques and implants have been described to overcome this problem; acetabular reconstruction and total hip arthroplasty still remains the standard surgical treatment, to relief pain and to improve function and quality of life. Harrington reconstruction of periacetabular metastatic disease combined with hip arthroplasty is one of the options that can address this clinical scenario safely; it is reproducible and cost-effective. In this review, we present case series of patients treated in our institution using Harrington rod technique for acetabular pathological lesions with good outcome.

A prospective longitudinal study investigating outcomes including patient-reported outcome measures after surgery for metastatic bone disease

Aims

Surgery is often indicated in patients with metastatic bone disease (MBD) to improve pain and maximize function. Few studies are available which report on clinically meaningful outcomes such as quality of life, function, and pain relief after surgery for MBD. This is the published protocol for the Bone Metastasis Audit — Patient Reported Outcomes (BoMA-PRO) multicentre MBD study. The primary objective is to ascertain patient-reported quality of life at three to 24 months post-surgery for MBD.

Methods

This will be a prospective, longitudinal study across six UK orthopaedic centres powered to identify the influence of ten patient variables on quality of life at three months after surgery for MBD. Adult patients managed for bone metastases will be screened by their treating consultant and posted out participant materials. If they opt in to participate, they will receive questionnaire packs at regular intervals from three to 24 months post-surgery and their electronic records will be screened until death or five years from recruitment. The primary outcome is quality of life as measured by the European Organisation for Research and the Treatment of Cancer Quality of Life questionnaire (EORTC-QLQ) C30 questionnaire. The protocol has been approved by the Newcastle & North Tyneside 2 Research Ethics Committee (REC ref 19/NE/0303) and the study is funded by the Royal College of Physicians and Surgeons of Glasgow (RCPSG) and the Association for Cancer Surgery (BASO-ACS).

Discussion

This will be the first powered study internationally to investigate patient-reported outcomes after orthopaedic treatment for bone metastases. We will assess quality of life, function, and pain relief at three to 24 months post-surgery and identify which patient variables are significantly associated with a good outcome after MBD treatment.

Cite this article: Bone Jt Open 2021;2(2):79–85.

Is a single dose of preoperative antibiotic therapy effective for patients treated with megaendoprosthesis after metastatic bone tumour resection?

Purpose The timing and number of doses of antibiotics required for megaendoprosthetic replacement (MPR) in metastatic bone disease (MBD) is a matter of debate. The aim of our study is to present the results of a prospective cohort of MPR for MBD receiving a single dose of antibiotic at induction of anaesthesia.

METHODS

All patients who underwent primary MPR in MBD were included in this prospective study. All penicillin-sensitive patients received one dose of cefuroxime 1.5gm intravenous at induction. In penicillin-allergic patients, teicoplanin 1.2gm and ciprofloxacin 500 mg intravenous was administered. The patients were followed up in the wound clinic and the specialist MBD clinic at 2 weeks, 3 months, 6 months and then annually. Data collected included demographics, primary tumours, surgical procedures, complications and duration of follow-up. All calculations were performed using SPSS^® 25(IBM, USA). A p value ≤ 0.05 was considered to be significant.

RESULTS

There were 51 patients with a mean age of 65.4 years. Procedures included proximal femoral replacement (35), distal femoral replacement (7), proximal humeral replacement (4), distal humeral replacement (3) and total femoral replacement (2). Thirty-seven patients received cefuroxime, and fourteen patients received teicoplanin and ciprofloxacin at induction of anaesthesia. The deep infection rate was 1.9%. Thirty-seven patients died with a median survival of 10 months (1 to 51 months). Mean follow-up was 18.9 months (1 to 70 months).

CONCLUSION

Single dose of preoperative antibiotics at anaesthetic induction seems to be safe and effective for preoperative prophylaxis in orthopaedic oncology.

C-reactive protein and tumour diagnosis predict survival in patients treated surgically for long bone metastases

PURPOSE

Surgical options for long bone metastases include intramedullary nail fixation or prosthetic reconstruction. Patients with a short life expectancy may benefit from less invasive surgery such as intramedullary nail fixation, while patients with a long life expectancy could be treated with more invasive surgery such as prosthetic reconstruction. The purpose of our study was to analyze the survival of patients treated surgically for long bone metastases, determining the prognostic factors affecting survival and analyzing the surgical complications and reoperation rates. Based on our results, we developed a prognostic score that helps to choose the best treatment for these patients. In addition, we compared the performance of our prognostic score with other previous prognostic models.

METHOD

We investigated prospectively potential clinical and laboratory prognostic factors in 159 patients with metastatic bone disease who underwent surgery with intramedullary nail fixation or prosthetic reconstruction. Clinical data were collected, recording the following data: age and sex of patients, primary tumour and time of diagnosis, number (single or multiple) and presentation (synchronous or metachronous) of bone metastases, presence of visceral metastases. The following laboratory data were analyzed: hemoglobin, leukocyte counts, lymphocyte counts, platelets count, alkaline phosphatase, and C-reactive protein.

RESULTS

Our study showed that pathological C-reactive protein and primary tumour diagnosis were significant negative independent prognostic factors at 12-month survival. Based on our results, we created a score using C-reactive protein and primary tumour diagnosis, creating three different prognostic groups: (A) good prognosis primary tumour and physiological CRP with probability of survival at 12 months of 88.9 [80.1-98.5]; (B) bad prognosis primary tumour and physiological CRP or good prognosis primary tumour and pathological CRP with a probability of survival at 12 months of 56.7 [45.4-70.7]; (C) bad prognosis primary tumour and pathological CRP with a probability of survival at 12 months of 12.5 [5.0-28.3]. Using ROC multiple analysis, our score (AUC = 0.816) was the most accurate in predicting a 12-month survival compared to previous prognostic models.

DISCUSSION

Patients treated surgically for long bone metastases with a life expectancy over 12 months should be treated with more durable reconstruction, while patients with a life expectancy less than 12 months should be treated with less invasive surgery. The diagnosis of primary cancer and C-reactive protein are two very simple data which every orthopaedic surgeon in any community hospital can easily rely on for any decision-making in the surgical treatment of a complex patient as with a patient with skeletal metastases.

CONCLUSION

Our prognostic score based on only two simple variables (C-reactive protein and primary tumour diagnosis) was able to predict the 12-month survival of patients treated surgically for long bone metastases and could be helpful in choosing the best treatment for these patients.

Thirty-day Outcomes After Surgery for Metastatic Bone Disease of the Extremities: An Analysis of the NSQIP Database

INTRODUCTION

Metastatic bone disease of the extremities is a notable cause of morbidity and mortality. Surgical management is not curative; therefore, risks and benefits of surgery must be carefully considered. Previous studies of surgical outcomes are limited by small sample sizes because of the rare incidence of these procedures. In this study, we aim to describe the rates of complications and mortality in the first 30 days after surgical treatment of metastatic bone disease of the femur and humerus.

METHODS

A retrospective review of patients in the National Surgical Quality Improvement Program database who underwent surgery between 2005 and 2016 was performed. Demographics, comorbidities, preoperative factors, surgical parameters, and postoperative complications were extracted. The cohort was also partitioned by surgical site and surgical modality.

RESULTS

One thousand one hundred fifty-four patients were identified, 13.1 percent of patients experienced one or more complications within 30 days of surgery. The most common complications were urinary tract infection (2.9%), deep vein thrombosis (2.5%), pneumonia (2.4%), pulmonary embolism (2.0%), and surgical site infections (1.9%). In addition, intraoperative or postoperative bleeding requiring transfusion occurred in 32.9% of cases. The rates of unplanned readmission and unplanned revision surgery were 12.7% and 4.1%, respectively. The 30-day mortality rate was 7.1%. Femur and arthroplasty cases were associated with a higher risk of bleeding requiring transfusion. Prophylactic stabilization was associated with a lower risk of unplanned revision surgery (P = 0.015) and a lower overall complication rate (P < 0.0001).

CONCLUSION

Our study demonstrates a higher 30-day mortality rate than previously reported. In additon, prophylactic stabilization of impending pathologic fractures may be associated with a lower risk of complications and unplanned revision surgery. The National Surgical Quality Improvement Program or other large database reports can help surgeons counsel patients appropriately regarding the risks and benefits of surgery.

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.