Alarming wear of the first-generation polyethylene liner of the cementless porous-coated Biomet Universal cup: 107 hips followed for mean 6 years

Life Expectancy After Treatment of Metastatic Bone Disease: An International Trend Analysis

INTRODUCTION

The decision to treat metastatic bone disease (MBD) surgically depends in part on patient life expectancy. We are unaware of an international analysis of how life expectancy among these patients has changed over time. Therefore, we asked (1) how has the life expectancy for patients treated for MBD changed over time, and (2) which, if any, of the common primary cancer types are associated with longer survival after treatment of MBD?

METHODS

We reviewed data collected from 2000 to 2022 in an international MBD database, as well as data used for survival model validation. We included 3,353 adults who underwent surgery and/or radiation. No patients were excluded. Patients were grouped by treatment date into period 1 (2000 to 2009), period 2 (2010 to 2019), and period 3 (2020 to 2022). Cumulative survival was portrayed using Kaplan-Meier curves; log-rank tests were used to determine significance at P < 0.05. Subgroup analyses by primary cancer diagnosis were performed.

RESULTS

Median survival in period 2 was longer than in period 1 ( P < 0.001). Median survival (at which point 50% of patients survived) had not been reached for period 3. Median survival was longer in period 2 for all cancer types ( P < 0.001) except thyroid. Only lung cancer reached median survival in period 3, which was longer compared with periods 1 and 2 ( P < 0.001). Slow-growth, moderate-growth, and rapid-growth tumors all demonstrated longer median survival from period 1 to period 2; only rapid-growth tumors reached median survival for period 3, which was longer compared with periods 1 and 2 ( P < 0.001).

DISCUSSION

Median duration of survival after treatment of MBD has increased, which was a consistent finding in nearly all cancer types. Longer survival is likely attributable to improvements in both medical and surgical treatments. As life expectancy for patients with MBD increases, surgical methods should be selected with this in mind.

LEVEL OF EVIDENCE

VI.

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.

The preoperative machine learning algorithm for extremity metastatic disease can predict 90-day and 1-year survival: An external validation study

BACKGROUND

The prediction of survival is valuable to optimize treatment of metastatic long-bone disease. The Skeletal Oncology Research Group (SORG) machine-learning (ML) algorithm has been previously developed and internally validated. The purpose of this study was to determine if the SORG ML algorithm accurately predicts 90-day and 1-year survival in an external metastatic long-bone disease patient cohort.

METHODS

A retrospective review of 264 patients who underwent surgery for long-bone metastases between 2003 and 2019 was performed. Variables used in the stochastic gradient boosting SORG algorithm were age, sex, primary tumor type, visceral/brain metastases, systemic therapy, and 10 preoperative laboratory values. Model performance was calculated by discrimination, calibration, and overall performance.

RESULTS

The SORG ML algorithms retained good discriminative ability (area under the cure [AUC]: 0.83; 95% confidence interval [CI]: 0.76-0.88 for 90-day mortality and AUC: 0.84; 95% CI: 0.79-0.88 for 1-year mortality), calibration, overall performance, and decision curve analysis.

CONCLUSION

The previously developed ML algorithms demonstrated good performance in the current study, thereby providing external validation. The models were incorporated into an accessible application (https://sorg-apps.shinyapps.io/extremitymetssurvival/) that may be freely utilized by clinicians in helping predict survival for individual patients and assist in informative decision-making discussion before operative management of long bone metastatic lesions.

Machine Learning Algorithm Guiding Local Treatment Decisions to Reduce Pain for Lung Cancer Patients with Bone Metastases, a Prospective Cohort Study

INTRODUCTION

As life expectancy increases for lung cancer patients with bone metastases, the need for personalized local treatment to reduce pain is expanding.

METHODS

Patients were treated by a multidisciplinary team (MDT), and local treatment including surgery, percutaneous osteoplasty, or radiation. Visual analog scale (VAS) and quality of life (QoL) scores were analyzed. VAS at 12 weeks after treatment was the main outcome. We developed and tested machine learning models to predict which patients should receive local treatment. Model discrimination was evaluated by the area under curve (AUC), and the best model was used for prospective decision-making accuracy validation.

RESULTS

Under the direction of MDT, 161 patients in the training set, 32 patients in the test set, and 36 patients in the validation set underwent local treatment. VAS in surgery, percutaneous osteoplasty, and radiation groups decreased significantly to 4.78 ± 1.28, 4.37 ± 1.36, and 5.39 ± 1.31 at 12 weeks, respectively (p < 0.05), with no significant differences among the three datasets, and improved QoL was also observed (p < 0.05). A decision tree (DT) model that included VAS, bone metastases character, Frankel classification, Mirels score, age, driver gene, aldehyde dehydrogenase 2, and enolase 1 expression had a best AUC in predicting whether patients would receive local treatment of 0.92 (95% CI 0.89-0.94) in the training set, 0.85 (95% CI 0.77-0.94) in the test set, and 0.88 (95% CI 0.81-0.96) in the validation set.

CONCLUSION

Local treatment provided significant pain relief and improved QoL. There were no significant differences in reducing pain and improving QoL among training, test, and validation sets. The DT model was best at determining whether patients should receive local treatment. Our machine learning model can help guide clinicians to make local treatment decisions to reduce pain.

TRIAL REGISTRATION

Trial registration number ChiCRT-ROC-16009501.

Evaluating the reoperation rate and hardware durability of three stabilizing implants for 105 malignant pathologic humerus fractures

INTRODUCTION

Many patients sustaining a malignant pathologic humerus fracture (MPHF) elect for surgical stabilization. Complications prompting reoperation can occur, leading to additional quality of life and financial cost. One common event preceding reoperation is a broken implant (BI). The purpose of this study was to identify the rate of reoperation following surgical stabilization of MPHF with three techniques - photodynamic bone stabilization (PBS), intramedullary nail (IMN), and cemented plate fixation (CPF) - and estimate to what extent improved implant durability might prevent reoperation.

MATERIALS AND METHODS

Retrospective data collection was performed, identifying 105 procedures (100 patients) who underwent non-articular MPHF surgery from 2010-2016: 19 PBS, 65 IMN, 21 CPF. All patients were followed for at least two years or until death.

RESULTS

Reoperation rates were similar at one year (10.5%,6.2%,4.8%, p = 737), two years (15.8%,6.2%,9.5%, p = 375), and final evaluation (15.8%,7.7%,14.3%, p = 248). The rate of BI for PBS, IMN, and CPF was 10.5%,0%, and 4.8% (p = 049 PBS/IMN) at one year, 15.8%,0%, and 9.5% (p = 010 PBS/IMN) at two years, and 15.8%,0%, and 14.3% (p = 010 IMN/PBS, p = 013 IMN/CPF) at final evaluation.

CONCLUSIONS

Reoperation rate was not significantly different at any time point. However, IMN surgery resulted in the lowest rate of broken implants (zero), statistically significant versus PBS at all time periods and versus CPF at final follow-up. PBS may eventually offer selected advantages for MPHF management, but current data suggests fragility must be thoughtfully considered.

Is Delayed Time to Surgery Associated with Increased Short-term Complications in Patients with Pathologic Hip Fractures?

BACKGROUND

Delayed time to surgery of at least 2 days after hospital arrival is well known to be associated with increased complications after standard hip fracture surgery; whether this association is present for pathologic hip fractures, however, is unknown.

QUESTIONS/PURPOSES

(1) After controlling for differences in patient characteristics, is delayed time to surgery (at least 2 days) for patients with pathologic hip fractures independently associated with increased complications compared with early surgery (fewer than 2 days)? (2) What preoperative factors are independently associated with major complications and mortality after surgery for pathologic hip fractures?

METHODS

A retrospective study was conducted using the American College of Surgeons National Surgical Quality Improvement Program database of pathologic hip fractures (including femoral neck, trochanteric, and subtrochanteric fractures) from 2007 to 2017. This database was chosen over other databases given the high-quality preoperative medical history and postoperative complication (including readmissions, reoperations, and mortality) data collected from patient medical records through the thirtieth postoperative day. Patients were identified using Common Procedural Terminology codes for hip fracture treatment (THA, hemiarthroplasty, proximal femur replacement, intramedullary nail, and plate and screw fixation) with associated operative diagnoses for pathologic fractures as identified with International Classification of Diseases codes. A total of 2627 patients with pathologic hip fractures were included in this study; 65% (1714) had surgery within 2 days and 35% (913) had surgery after that time. Patient demographics, hospitalization information, and 30-day postoperative complications were recorded. Differences in characteristics between patients who underwent surgery in the early and delayed time periods were assessed with chi-square tests for categorical variables and t-tests for continuous variables. Delayed-surgery patients were more medically complex at the time of admission than early-surgery patients, including having higher American Society of Anesthesiologists classification (mean ± SD 3.18 ± 0.61 versus 2.94 ± 0.60; p < 0.001) and prevalence of advanced, "disseminated" cancer (53% versus 39%; p < 0.001). Propensity-adjusted multivariable logistic regression analyses were performed to assess the effect of delayed time to surgery alone on the various outcome measures. Additional independent risk factors for major complications and mortality were identified using backwards stepwise regressions.

RESULTS

After controlling for baseline factors, the only outcome associated with delayed surgery was extended postoperative length of stay (odds ratio 1.94 [95% CI 1.62 to 2.33]; p < 0.001). Delayed surgery was not associated with any postoperative complications, including major complications (OR 1.23 [95% CI 0.94 to 1.6]; p = 0.13), pulmonary complications (OR 1.24 [95% CI 0.83 to 1.86]; p = 0.29), and mortality (OR 1.26 [95% CI 0.91 to 1.76]; p = 0.16). Histories of chronic obstructive pulmonary disease (OR 2.48), congestive heart failure (OR 2.64), and disseminated cancer (OR 1.68) were associated with an increased risk of major complications, while dependent functional status (OR 2.27), advanced American Society of Anesthesiologists class (IV+ versus I-II, OR 4.81), and disseminated cancer were associated with an increased risk of mortality (OR 2.2; p ≤ 0.002 for all).

CONCLUSIONS

After controlling for baseline patient factors, delayed time to surgery was not independently associated with increased 30-day complications after surgical treatment of pathologic hip fractures. These results are in contrast to the traditional dogma for standard hip fractures that surgery within 2 days of hospital arrival is associated with reduced complications. Although surgery should not be delayed needlessly, if the surgeon feels that additional time could benefit the patient, the results of this study suggest surgeons should not expedite surgery because of the risk of surgical delay observed for standard hip fractures.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Development and Internal Validation of Machine Learning Algorithms for Preoperative Survival Prediction of Extremity Metastatic Disease

BACKGROUND

A preoperative estimation of survival is critical for deciding on the operative management of metastatic bone disease of the extremities. Several tools have been developed for this purpose, but there is room for improvement. Machine learning is an increasingly popular and flexible method of prediction model building based on a data set. It raises some skepticism, however, because of the complex structure of these models.

QUESTIONS/PURPOSES

The purposes of this study were (1) to develop machine learning algorithms for 90-day and 1-year survival in patients who received surgical treatment for a bone metastasis of the extremity, and (2) to use these algorithms to identify those clinical factors (demographic, treatment related, or surgical) that are most closely associated with survival after surgery in these patients.

METHODS

All 1090 patients who underwent surgical treatment for a long-bone metastasis at two institutions between 1999 and 2017 were included in this retrospective study. The median age of the patients in the cohort was 63 years (interquartile range [IQR] 54 to 72 years), 56% of patients (610 of 1090) were female, and the median BMI was 27 kg/m (IQR 23 to 30 kg/m). The most affected location was the femur (70%), followed by the humerus (22%). The most common primary tumors were breast (24%) and lung (23%). Intramedullary nailing was the most commonly performed type of surgery (58%), followed by endoprosthetic reconstruction (22%), and plate screw fixation (14%). Missing data were imputed using the missForest methods. Features were selected by random forest algorithms, and five different models were developed on the training set (80% of the data): stochastic gradient boosting, random forest, support vector machine, neural network, and penalized logistic regression. These models were chosen as a result of their classification capability in binary datasets. Model performance was assessed on both the training set and the validation set (20% of the data) by discrimination, calibration, and overall performance.

RESULTS

We found no differences among the five models for discrimination, with an area under the curve ranging from 0.86 to 0.87. All models were well calibrated, with intercepts ranging from -0.03 to 0.08 and slopes ranging from 1.03 to 1.12. Brier scores ranged from 0.13 to 0.14. The stochastic gradient boosting model was chosen to be deployed as freely available web-based application and explanations on both a global and an individual level were provided. For 90-day survival, the three most important factors associated with poorer survivorship were lower albumin level, higher neutrophil-to-lymphocyte ratio, and rapid growth primary tumor. For 1-year survival, the three most important factors associated with poorer survivorship were lower albumin level, rapid growth primary tumor, and lower hemoglobin level.

CONCLUSIONS

Although the final models must be externally validated, the algorithms showed good performance on internal validation. The final models have been incorporated into a freely accessible web application that can be found at https://sorg-apps.shinyapps.io/extremitymetssurvival/. Pending external validation, clinicians may use this tool to predict survival for their individual patients to help in shared treatment decision making.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Is routine MRI necessary to exclude pathological fractures in patients with an oncological history?

INTRODUCTION

Magnetic resonance imaging (MRI) is the radiological modality of choice for diagnosing pathological fractures in situations of diagnostic uncertainty. With the increasing availability of MRI, we have observed a disturbing trend in utilising routine MRI scans to exclude pathological fractures in all patients with a history of cancer. The study objective was to determine if routine use of MRI scans in such patients is truly necessary and if other predictive factors can be utilised in lieu of the MRI scan.

MATERIALS AND METHODS

A 3-year retrospective study was conducted reviewing all extremity MRI scans performed for suspected pathological fractures and compared to X-rays. All patients presented with an extremity fracture, a known diagnosis of solid organ cancer and had an MRI to determine if the fracture was pathological. Subjects were followed up with serial X-rays up to 1 year.

RESULTS

84 subjects were recruited. Comparing X-rays alone with MRI scans revealed 92% sensitivity and 98% specificity in detecting pathological fractures. Using X-rays in combination with an absent history of trauma increases the sensitivity to 100% but reduced the specificity to 91%. None of subjects in cancer remission had pathological fractures.

CONCLUSIONS

MRI is an imperative tool for operative planning in pathological fractures; however, we recommend against the routine use of MRI to diagnose pathological fractures in oncological patients. Patients with solid organ cancer remission, a positive history of significant trauma prior to sustaining the fracture, and the absence of pathological features on plain radiographs are strongly predictive against pathological fractures.

What Factors Are Associated With Implant Breakage and Revision After Intramedullary Nailing for Femoral Metastases?

BACKGROUND

Actual and impending pathologic fractures of the femur are commonly treated with intramedullary nails because they provide immediate stabilization with a minimally invasive procedure and enable direct weightbearing. However, complications and revision surgery are prevalent, and despite common use, there is limited evidence identifying those factors that are associated with complications.

QUESTIONS/PURPOSES

Among patients treated with intramedullary nailing for femoral metastases, we asked the following questions: (1) What is the cumulative incidence of local complications? (2) What is the cumulative incidence of implant breakage and what factors are associated with implant breakage? (3) What is the cumulative incidence of revision surgery and what factors are associated with revision surgery?

METHODS

Between January 2000 and December 2015, 245 patients in five centers were treated with intramedullary nails for actual and impending pathologic fractures of the femur caused by bone metastases. During that period, the general indications for intramedullary nailing of femoral metastases were impending fractures of the trochanter region and shaft and actual fractures of the trochanter region if sufficient bone stock remained; nails were used for lesions of the femoral shaft if they were large or if multiple lesions were present. Of those treated with intramedullary nails, 51% (117) were actual fractures and 49% (111) were impending fractures. A total of 60% (128) of this group were women; the mean age was 65 years (range, 29-93 years). After radiologic followup (at 4-8 weeks) with the orthopaedic surgeon, because of the palliative nature of these treatments, subsequent in-person followup was performed by the primary care provider on an as-needed basis (that is, as desired by the patient, without any scheduled visits with the orthopaedic surgeon) throughout each patient's remaining lifetime. However, there was close collaboration between the primary care providers and the orthopaedic team such that orthopaedic complications would be reported. A total of 67% (142 of 212) of the patients died before 1 year, and followup ranged from 0.1 to 175 months (mean, 14.4 months). Competing risk models were used to estimate the cumulative incidence of local complications (including persisting pain, tumor progression, and implant breakage), implant breakage separately, and revision surgery (defined as any reoperation involving the implant other than débridement with implant retention for infection). A cause-specific multivariate Cox regression model was used to estimate the association of factors (fracture type/preoperative radiotherapy and fracture type/use of cement) with implant breakage and revision, respectively.

RESULTS

Local complications occurred in 12% (28 of 228) of the patients and 6-month cumulative incidence was 8% (95% confidence interval [CI], 4.7-11.9). Implant breakage occurred in 8% (18 of 228) of the patients and 6-month cumulative incidence was 4% (95% CI, 1.4-6.5). Independent factors associated with increased risk of implant breakage were an actual (as opposed to impending) fracture (cause-specific hazard ratio [HR_cs], 3.61; 95% CI, 1.23-10.53, p = 0.019) and previous radiotherapy (HR_cs, 2.97; 95% CI, 1.13-7.82, p = 0.027). Revisions occurred in 5% (12 of 228) of the patients and 6-month cumulative incidence was 2.2% (95% CI, 0.3-4.1). The presence of an actual fracture was independently associated with a higher risk of revision (HR_cs, 4.17; 95% CI, 0.08-0.82, p = 0.022), and use of cement was independently associated with a lower risk of revision (HR_cs, 0.25; 95% CI, 1.20-14.53, p = 0.025).

CONCLUSIONS

The cumulative incidence of local complications, implant breakage, and revisions is low, mostly as a result of the short survival of patients. Based on these results, surgeons should consider use of cement in patients with intramedullary nails with actual fractures and closer followup of patients after actual fractures and preoperative radiotherapy. Future, prospective studies should further analyze the effects of adjuvant therapies and surgery-related factors on the risk of implant breakage and revisions.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Cytotoxic effects of zoledronic acid-loaded hydroxyapatite and bone cement in malignant tumors

Metastatic and primary bone tumors are malignant tumors affecting the skeleton. Although the prognosis of patients with these tumors has improved with the development of effective chemotherapy, the challenges of local recurrence, subsequent osteolysis, degradation of bone strength and unresectable tumors persist. Local control of these tumors is therefore a key strategy to address these limitations. The third-generation bisphosphonate (BP), zoledronic acid (ZOL), has been demonstrated to reduce osteoclasts and exhibited potent antitumor effects in a number of malignancies. Hydroxyapatite (HA) and polymethyl methacrylate (PMMA) bone cement are used in orthopedic surgery as bone graft substitutes, for implant arthroplasty and bone strengthening, and as a sustained-release system for drugs such as antibiotics. At present, the antitumor effects of ZOL-loaded HA in vitro or in vivo or of ZOL-loaded bone cement in vivo have not been described. Therefore, the present study assessed the effects of ZOL-loaded HA and bone cement in malignant tumor cells. The two materials exerted strong antitumor effects against osteosarcoma, fibrosarcoma, synovial sarcoma, renal cancer, prostate cancer and lung cancer cells upon releasing ZOL. The antitumor effects of ZOL-loaded HA were less potent compared with those of ZOL-loaded bone cement, possibly as BPs exhibit higher affinity to HA. ZOL-loaded bone cement also exerted antitumor effects against pulmonary metastases and primary lesions, without exhibiting systemic toxicity in vivo. These results demonstrate that these materials may be beneficial for the treatment of malignant bone tumors, including metastatic bone tumors. In addition, as these materials are already in clinical use, such applications may be easily implemented.

Consensus on Surgical Management of Myeloma Bone Disease

Myeloma bone disease (MBD), the skeletal lesions caused by multiple myeloma, is also known as skeletal related events and includes bone pain, osteoporosis, pathological fractures, osteolytic bone lesions, spinal instability, spinal cord and nerve root compression and extramedullary plasmacytoma. It is now generally accepted that patients with these complications usually require surgical management and that such treatment is safe and effective. The aims of surgical interventions are to alleviate pain, improve quality of life, treat potential or existing pathological fractures, decompress the spinal cord and nerve roots, and reestablish bone continuity. Thus far, there have not been uniform standards for surgical treatment of MBD. The Surgeon's Committee of the Chinese Myeloma Working Group has therefore achieved a consensus with the aim of providing guidance for clinicians and benefitting patients with MBD. This consensus focuses on the treatment of MBD, including its clinical definition and characteristics, diagnosis and surgical management. This expert consensus document was compiled after discussion and revision by experts from several relevant institutions in China. However, it is only an interim guide that cannot be enforced legally. It will be updated with development of new techniques of treatment.

Assessment of wear and periacetabular osteolysis using dual energy computed tomography on a pig cadaver to identify the lowest acceptable radiation dose

Objectives

Computed tomography (CT) plays an important role in evaluating wear and periacetabular osteolysis (PAO) in total hip replacements. One concern with CT is the high radiation exposure since standard pelvic CT provides approximately 3.5 millisieverts (mSv) of radiation exposure, whereas a planar radiographic examination with three projections totals approximately 0.5 mSv. The objective of this study was to evaluate the lowest acceptable radiation dose for dual-energy CT (DECT) images when measuring wear and periacetabular osteolysis in uncemented metal components.

Materials and Methods

A porcine pelvis with bilateral uncemented hip prostheses and with known linear wear and acetabular bone defects was examined in a third-generation multidetector DECT scanner. The examinations were performed with four different radiation levels both with and without iterative reconstruction techniques. From the high and low peak kilo voltage acquisitions, polychrmoatic images were created together with virtual monochromatic images of energies 100 kiloelectron volts (keV) and 150 keV.

Results

We could assess wear and PAO while substantially lowering the effective radiation dose to 0.7 mSv for a total pelvic view with an accuracy of around 0.5 mm for linear wear and 2 mm to 3 mm for PAO.

Conclusion

CT for detection of prosthetic wear and PAO could be used with clinically acceptable accuracy at a radiation exposure level equal to plain radiographic exposures.

Cite this article: B. Sandgren, M. Skorpil, P. Nowik, H. Olivecrona, J. Crafoord, L. Weidenhielm, A. Persson. Assessment of wear and periacetabular osteolysis using dual energy computed tomography on a pig cadaver to identify the lowest acceptable radiation dose. Bone Joint Res 2016;5:307–313. DOI: 10.1302/2046-3758.57.2000566.

Extent of Surgery Does Not Influence 30-Day Mortality in Surgery for Metastatic Bone Disease: An Observational Study of a Historical Cohort

Estimating patient survival has hitherto been the main focus when treating metastatic bone disease (MBD) in the appendicular skeleton. This has been done in an attempt to allocate the patient to a surgical procedure that outlives them. No questions have been addressed as to whether the extent of the surgery and thus the surgical trauma reduces survival in this patient group. We wanted to evaluate if perioperative parameters such as blood loss, extent of bone resection, and duration of surgery were risk factors for 30-day mortality in patients having surgery due to MBD in the appendicular skeleton. We retrospectively identified 270 consecutive patients who underwent joint replacement surgery or intercalary spacing for skeletal metastases in the appendicular skeleton from January 1, 2003 to December 31, 2013. We collected intraoperative (duration of surgery, extent of bone resection, and blood loss), demographic (age, gender, American Society of Anesthesiologist score [ASA score], and Karnofsky score), and disease-specific (primary cancer) variables. An association with 30-day mortality was addressed using univariate and multivariable analyses and calculation of odds ratio (OR). All patients were included in the analysis. ASA score 3 + 4 (OR 4.16 [95% confidence interval, CI, 1.80-10.85], P = 0.002) and Karnofsky performance status below 70 (OR 7.34 [95% CI 3.16-19.20], P < 0.001) were associated with increased 30-day mortality in univariate analysis. This did not change in multivariable analysis. No parameters describing the extent of the surgical trauma were found to be associated with 30-day mortality. The 30-day mortality in patients undergoing surgery for MBD is highly dependent on the general health status of the patients as measured by the ASA score and the Karnofsky performance status. The extent of surgery, measured as duration of surgery, blood loss, and degree of bone resection were not associated with 30-day mortality.

The investigation and management of suspected malignant pathological fractures: a review for the general orthopaedic surgeon

The management of malignant pathological fractures necessitates careful diagnostic work-up, pre-operative investigation, planning and multidisciplinary input from specialists in the fields of radiology, pathology, oncology, trauma and orthopaedics. Malignant and non-malignant conditions including metabolic disorders, benign tumours and pharmacological therapies can be implicated. The majority of patients who present with suspected pathological fractures will be managed by general orthopaedic and trauma surgeons rather than specialists in orthopaedic oncology. Skeletal metastases can result in considerable morbidity and predispose to pathological fractures. With advances in the medical management of malignancy, life expectancy in cancer patients is increasing, leading to an increasing risk of skeletal metastasis and the potential for pathological fractures. Conventional modes of trauma fixation for pathological fractures may not be appropriate. The aim of this review is to outline diagnostic and management strategies for patients who present with a long bone fracture that is potentially pathological in nature.

Side effects of analgesia may significantly reduce quality of life in symptomatic multiple myeloma: a cross-sectional prevalence study

BACKGROUND

Pain is a common symptom in patients with multiple myeloma (MM). Many patients are dependent on analgesics and in particular opioids, but there is limited information on the impact of these drugs and their side effects on health-related quality of life (HRQoL).

METHOD

In a cross-sectional study, semi-structured interviews were performed in 21 patients attending the hospital with symptomatic MM on pain medications. HRQoL was measured using items 29 and 30 of the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30.

RESULTS

Patients were able to recall a median of two (range 0-4) analgesics. They spontaneously identified a median of two (range 1-5) side effects attributable to their analgesic medications. Patients' assessment of HRQoL based on the EORTC QLQ-C30 questions 29/30 was mean 48.3 (95 % CI; 38.7-57.9) out of 100. Patients' assessment of their HRQoL in the hypothetical situation, in which they would not experience any side effects from analgesics, was significantly higher: 62.6 (53.5-71.7) (t test, p = 0.001).

CONCLUSION

This study provides, for the first time, evidence that side effects of analgesics are common in symptomatic MM and may result in a statistically and clinically significant reduction of self-reported HRQoL.

The outcome of surgical treatment for peri-acetabular metastases

We reviewed the outcome of patients who had been treated operatively for symptomatic peri-acetabular metastases and present an algorithm to guide treatment. The records of 81 patients who had been treated operatively for symptomatic peri-acetabular metastases between 1987 and 2010 were identified. There were 27 men and 54 women with a mean age of 61 years (15 to 87). The diagnosis, size of lesion, degree of pelvic continuity, type of reconstruction, World Health Organization performance status, survival time, pain, mobility and complications including implant failure were recorded in each case. The overall patient survivorship at five years was 5%. The longest lived patient survived 16 years from the date of diagnosis. The mean survival was 23 months (< 1 to 16 years) and the median was 15 months. At follow-up 14 patients remained alive. Two cementoplasties failed because of local disease progression. Three Harrington rods broke: one patient needed a subsequent Girdlestone procedure. One 'ice-cream cone' prosthesis dislocated and was subsequently revised without further problems. We recommend the 'ice-cream cone' for pelvic discontinuity and Harrington rod reconstruction for severe bone loss. Smaller defects can be safely managed using standard revision hip techniques.

Accelerated polyethylene wear and early failure of the uncemented Reflection acetabular component: a ten to fifteen-year follow-up study

PURPOSE

The Reflection® second-generation uncemented acetabular component was designed to address increased rates of failure observed with the early acetabular designs. However, the reported survivorship of this acetabular component has been conflicting. The aim of this study was to describe the ten to 15-year survivorship and polyethylene wear rate for the uncemented Reflection® acetabular component performed as part of a primary total hip replacement.

METHODS

One hundred and four consecutive Reflection® uncemented acetabular components in 97 patients were identified from a prospective arthroplasty database with a minimum of ten years of follow-up. No patient was lost to follow-up. Mean cohort age was 59.1 years.

RESULTS

There were 24 revisions of the acetabular component. The all-cause survival rate at ten years was 77.2% [95% confidence interval (CI) 73.9-80.5]. Mean linear wear was 0.20 mm [standard deviation (SD) 0.08] per year and the volumetric wear was 106.2 mm(3) per year. At final follow-up, more than half the patients had osteolysis identified around the femoral component. The mean Oxford Hip Score was 35.6 (SD 9.8) at a mean follow-up of 11.9 years, with six (11.1%) excellent, 26 (48.1%) good, 17 (31.5%) fair and five (9.3%) poor outcomes. Despite the fact that more than a third had a fair or poor outcome, only four (7.4%) were not satisfied with their hip.

CONCLUSIONS

Due to the high rate of relatively asymptomatic polyethylene wear and osteolysis associated with this acetabular component, in our department, we now review all surviving patients both clinically and radiographically on an annual basis.

International Myeloma Working Group recommendations for the treatment of multiple myeloma-related bone disease

PURPOSE

The aim of the International Myeloma Working Group was to develop practice recommendations for the management of multiple myeloma (MM) -related bone disease.

METHODOLOGY

An interdisciplinary panel of clinical experts on MM and myeloma bone disease developed recommendations based on published data through August 2012. Expert consensus was used to propose additional recommendations in situations where there were insufficient published data. Levels of evidence and grades of recommendations were assigned and approved by panel members.

RECOMMENDATIONS

Bisphosphonates (BPs) should be considered in all patients with MM receiving first-line antimyeloma therapy, regardless of presence of osteolytic bone lesions on conventional radiography. However, it is unknown if BPs offer any advantage in patients with no bone disease assessed by magnetic resonance imaging or positron emission tomography/computed tomography. Intravenous (IV) zoledronic acid (ZOL) or pamidronate (PAM) is recommended for preventing skeletal-related events in patients with MM. ZOL is preferred over oral clodronate in newly diagnosed patients with MM because of its potential antimyeloma effects and survival benefits. BPs should be administered every 3 to 4 weeks IV during initial therapy. ZOL or PAM should be continued in patients with active disease and should be resumed after disease relapse, if discontinued in patients achieving complete or very good partial response. BPs are well tolerated, but preventive strategies must be instituted to avoid renal toxicity or osteonecrosis of the jaw. Kyphoplasty should be considered for symptomatic vertebral compression fractures. Low-dose radiation therapy can be used for palliation of uncontrolled pain, impending pathologic fracture, or spinal cord compression. Orthopedic consultation should be sought for long-bone fractures, spinal cord compression, and vertebral column instability.

A long femoral stem is not always required in hip arthroplasty for patients with proximal femur metastases

BACKGROUND

During hip arthroplasties for treating proximal femur metastases, a long femoral stem frequently is used, presumably protecting the entire femur against progression of the existing lesions or development of new lesions. However, it is unclear whether a long stem is really required.

QUESTIONS/PURPOSES

We therefore determined in patients with proximal femur metastases (1) the reoperation rate related to different stem lengths after hip arthroplasty, (2) the risk of tumor progression in the same femur (the progression of preexisting lesions and the development of new distal femur lesions), and (3) complications.

METHODS

We retrospectively reviewed 203 patients (206 femurs) with proximal femur metastases treated with hip arthroplasty. These femurs were divided into three groups based on femoral stem length: short stem (SS), 12 to 14 cm; medium stem (MS), 20 to 24 cm; and long stem (LS), 25 to 35 cm. We reviewed reoperations, disease progression in the same femur, and complications. Minimum followup was 2 days (median, 487 days; range, 2-4853 days), with most patients followed to their death.

RESULTS

Only three femurs were revised owing to tumor progression, with no difference among the SS, MS, and LS groups. Two SS prostheses were revised for nononcologic reasons. Tumor progression in the same femur was uncommon during the patient's survival, with 11 femurs showing progression of the proximal lesion and five femurs showing new distal lesions. The complication rate was higher in the LS group (28%) than the combined rate in the MS and SS groups (16%), especially acute cardiopulmonary complications (18% versus 7.5%).

CONCLUSIONS

Reoperation after hip arthroplasty for proximal femur metastases is uncommon and not correlated with femoral stem length. Considering the high complication rate associated with a LS hip prosthesis, we do not believe its routine use is justified.

Prophylactic stabilization for bone metastases, myeloma, or lymphoma: do we need to protect the entire bone?

BACKGROUND

The current operative standard of care for disseminated malignant bone disease suggests stabilizing the entire bone to avoid the need for subsequent operative intervention but risks of doing so include complications related to embolic phenomena.

QUESTIONS/PURPOSES

We questioned whether progression and reoperation occur with enough frequency to justify additional risks of longer intramedullary devices.

METHODS

A retrospective chart review was done for 96 patients with metastases, myeloma, or lymphoma who had undergone stabilization or arthroplasty of impending or actual femoral or humeral pathologic fractures using an approach favoring intramedullary fixation devices and long-stem arthroplasty. Incidence of progressive bone disease, reoperation, and complications associated with fixation and arthroplasty devices in instrumented femurs or humeri was determined.

RESULTS

At minimum 0 months followup (mean, 11 months; range, 0-72 months), 80% of patients had died. Eleven of 96 patients (12%) experienced local bony disease progression; eight had local progression at the original site, two had progression at originally recognized discretely separate lesions, and one had a new lesion develop in the bone that originally was surgically treated. Six subjects (6.3%) required repeat operative intervention for symptomatic failure. Twelve (12.5%) patients experienced physiologic nonfatal complications potentially attributable to embolic phenomena from long intramedullary implants.

CONCLUSIONS

Because most patients in this series were treated with the intent to protect the bone with long intramedullary implants when possible, the reoperation rate may be lower than if the entire bone had not been protected. However, the low incidence of disease progression apart from originally identified lesions (one of 96) was considerably lower than the physiologic complication rate (12 of 96) potentially attributable to long intramedullary implants.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

External validation of the Bayesian Estimated Tools for Survival (BETS) models in patients with surgically treated skeletal metastases

Background

We recently developed two Bayesian networks, referred to as the Bayesian-Estimated Tools for Survival (BETS) models, capable of estimating the likelihood of survival at 3 and 12 months following surgery for patients with operable skeletal metastases (BETS-3 and BETS-12, respectively). In this study, we attempted to externally validate the BETS-3 and BETS-12 models using an independent, international dataset.

Methods

Data were collected from the Scandinavian Skeletal Metastasis Registry for patients with extremity skeletal metastases surgically treated at eight major Scandinavian referral centers between 1999 and 2009. These data were applied to the BETS-3 and BETS-12 models, which generated a probability of survival at 3 and 12 months for each patient. Model robustness was assessed using the area under the receiver-operating characteristic curve (AUC). An analysis of incorrect estimations was also performed.

Results

Our dataset contained 815 records with adequate follow-up information to establish survival at 12 months. All records were missing data including the surgeon’s estimate of survival, which was previously shown to be a first-degree associate of survival in both models. The AUCs for the BETS-3 and BETS-12 models were 0.79 and 0.76, respectively. Incorrect estimations by both models were more commonly optimistic than pessimistic.

Conclusions

The BETS-3 and BETS-12 models were successfully validated using an independent dataset containing missing data. These models are the first validated tools for accurately estimating postoperative survival in patients with operable skeletal metastases of the extremities and can provide the surgeon with valuable information to support clinical decisions in this patient population.

Evidence for orthopaedic surgery in the treatment of metastatic bone disease of the extremities: a review article

BACKGROUND

The decision to offer orthopaedic surgery to patients with metastatic bone disease is often difficult and requires an understanding of the underlying disease, the patient's needs or wishes, the expected outcomes and the principles of surgery.

AIM

We aimed to look at the literature to support the role of orthopaedic surgery for skeletal metastasis in improving key outcomes such as pain, quality of life and physical functioning.

DESIGN

Review article.

DATA SOURCES

The 'Dialog Datastar' database was used to access Medline and other resources from 1951 to December 2009 using keywords 'Metasta$' AND 'Bone or Skeletal' AND 'Results Or Outcome Or Surg$ Or Management'.

RESULTS

The majority of the studies that have looked at these key outcomes are limited by their design and their use of non-validated outcome measures. This study has detailed the measures to assess outcome, predict survival, predict fracture and how to arrive at key decisions, such as when to operate and when not to operate on these patients.

CONCLUSION

Timely and appropriate surgical intervention reliably alleviates pain and improves quality of life and can be undertaken with few complications in most patients. Although most procedures can be undertaken by non-specialists, consultation with other members of the multidisciplinary team is mandatory, and in complex cases, referral to a specialist orthopaedic oncology centre can be helpful.

No improvement in long-term wear and revision rates with the second-generation Biomet cup (RingLoc) in young patients: 141 hips followed for median 12 years

BACKGROUND

A number of excellent results with the cementless titanium femoral component of the Mallory Head Total Hip Replacement have been published. Unfortunately, these excellent results have been counteracted by the poor performance of the cementless titanium acetabular components. In 1994, the HexLoc acetabular component was replaced with a second-generation design, the RingLoc. We hypothesized that the new generation would have improved the results.

METHODS

We retrospectively studied 111 consecutive patients (150 hips) younger than 55 years. Median follow-up time was 14 (6-18) years for the HexLoc and 10 (1-14) years for the RingLoc. 7 patients were lost to follow-up and 7 patients died. The 10-year survival rate, radiographic liner wear, and radiographic signs of prosthesis failure were compared between the 2 acetabular components.

RESULTS

The Kaplan-Meier survival estimate with revision for any reason as the endpoint showed a 10-year survival of 89% (95% CI: 81-97) for the HexLoc and 92% (CI: 85-98) for the RingLoc. The mean annual wear rate for the HexLoc was 0.16 (SD 0.16) mm and it was 0.15 (0.1) mm for the RingLoc (p = 0.3). The radiographic signs of failure were equally distributed between the 2 groups.

INTERPRETATION

Compared to the HexLoc type, the RingLoc system did not improve the mean percentage survival at 10 years; nor did it reduce the liner wear. Despite correction of the known design flaws in the HexLoc design, the RingLoc system did not show a clinically relevant improvement compared to its predecessor.

The Ringloc liner compared with the Hexloc liner in total hip arthroplasty

The aim of this study was to compare the 10-year survival rate, pelvic osteolysis frequency and linear head penetration rate of the Hexloc and Ringloc liners used together with a partially threaded porous and hydroxyapatite coated cup and the Bi-Metric uncemented femoral stem. The 15-year results for the cup with the Hexloc liner are also reported. We included 332 consecutive hips (166 Hexloc and 166 Ringloc) on 281 patients in the study. Revisions of prosthesis components were recorded and pelvic osteolytic lesions were assessed using radiographs and computed tomography. The linear head penetration rate was measured using the Martell method. The 10-year survival rate of the liner with revision due to liner wear and/or osteolysis as endpoint was 88% for the Hexloc liner and 98% for the Ringloc liner. The 15-year survival rate of the Hexloc liner was 67%. Pelvic osteolysis was found in 27% of the Hexloc and 19% of the Ringloc hips. After 15 years, 53% of the Hexloc hips had developed an osteolytic lesion. The linear head penetration rate was 0.16 mm/year for the Hexloc liner and 0.12 mm/year for the Ringloc liner. This paper is the first to describe the rapidly deteriorating survival up to 15 years with the old generation gamma-in-air sterilized polyethylene used in Hexloc liners. The newer Ringloc liner with the ArCom™ polyethylene has superior clinical results but a linear wear rate and frequency of osteolytic lesions that is higher than expected.

Estimating survival in patients with operable skeletal metastases: an application of a bayesian belief network

Background

Accurate estimations of life expectancy are important in the management of patients with metastatic cancer affecting the extremities, and help set patient, family, and physician expectations. Clinically, the decision whether to operate on patients with skeletal metastases, as well as the choice of surgical procedure, are predicated on an individual patient's estimated survival. Currently, there are no reliable methods for estimating survival in this patient population. Bayesian classification, which includes Bayesian belief network (BBN) modeling, is a statistical method that explores conditional, probabilistic relationships between variables to estimate the likelihood of an outcome using observed data. Thus, BBN models are being used with increasing frequency in a variety of diagnoses to codify complex clinical data into prognostic models. The purpose of this study was to determine the feasibility of developing Bayesian classifiers to estimate survival in patients undergoing surgery for metastases of the axial and appendicular skeleton.

Methods

We searched an institution-owned patient management database for all patients who underwent surgery for skeletal metastases between 1999 and 2003. We then developed and trained a machine-learned BBN model to estimate survival in months using candidate features based on historical data. Ten-fold cross-validation and receiver operating characteristic (ROC) curve analysis were performed to evaluate the BNN model's accuracy and robustness.

Results

A total of 189 consecutive patients were included. First-degree predictors of survival differed between the 3-month and 12-month models. Following cross validation, the area under the ROC curve was 0.85 (95% CI: 0.80–0.93) for 3-month probability of survival and 0.83 (95% CI: 0.77–0.90) for 12-month probability of survival.

Conclusions

A robust, accurate, probabilistic naïve BBN model was successfully developed using observed clinical data to estimate individualized survival in patients with operable skeletal metastases. This method warrants further development and must be externally validated in other patient populations.

Intramedullary nails for long bone metastases: why do they fail?

Metastatic disease to long bones is common and often requires stabilization to treat or prevent fracture. Intramedullary fixation is used in many metaphyseal and diaphyseal lesions. The goal of this study was to investigate the causes of and risk factors for reconstructive failure in intramedullary fixation of metastatic disease. We performed a retrospective review of 112 consecutive reconstructions for metastatic disease treated with an isolated intramedullary nail. There were 81 reconstructions in the femur, 25 in the humerus, and 6 in the tibia. All included patients were followed until death or reconstructive failure. All surviving patients had a minimum 2-year follow-up.Ten failures required construct revision. Median time to revision was 17.9 months (range, 3-93 months). The causes of failure included surgeon error, tumor progression, nonunion, and hardware failure. Patients with short survival times (P<.001) or a diagnosis of lung cancer (P=.029) were unlikely to fail. Revision was required in 6 solitary lesions (P=.012), 3 cases of lymphoma (P=.002), 3 cases of progressive renal cell carcinoma (P=.040), and 2 radiation-associated fractures (P=.007).Intramedullary stabilization is a successful operation for appropriate lesions. Failures may be minimized with proper implant selection and surgical technique, resection or curettage of renal cell carcinoma, avoidance of radiation-associated fractures, and overestimating patient survival.

Acetabular UHMWPE survival and wear changes with different manufacturing techniques

BACKGROUND

Polyethylene wear may be affected by the type of polyethylene resin, manufacturing technique, degree of thermal stabilization, and sterilization technique.

QUESTIONS/PURPOSES

We therefore compared femoral head penetration into the PE and cup survival using the same cup system with different PE resins, manufacturing, and sterilization techniques.

METHODS

Our study group consisted of 1912 THAs performed using the same uncemented cup and identical 28-mm cobalt-chrome heads. The polyethylene varied as follows: Group 1 (94 cups), GUR 4150 resin, ram-extruded, sterilized in air, no barrier packaging; Group 2 (74 cups), same as Group 1 but sterilized in argon; Group 3 (75 cups), Himont 1900 resin, compression-molded bar stock, sterilized in argon, no barrier packaging; Group 4 (620 cups), same as Group 3 except with barrier packing; Group 5 (711 cups), GUR 1050 resin, compression-molded bar stock, sterilized in argon gas with barrier packaging; and Group 6 (338 cups), GUR 1050 resin, compression-molded bar stock, sterilized in argon with barrier packaging, irradiated with 50 kGy, heated below melting temperature, machined, and finally placed in nonbarrier packaging with gas plasma sterilization. Minimum followup was 2 years (average, 7 years; range, 2-17 years).

RESULTS

Femoral head penetration averaged 0.05 mm per year for Groups 5 and 6 and was substantially lower than for Groups 1 to 4. Cup survival was higher at seven years in Groups 3, 4, and 5, and at 10 years in group 4 when compared to groups 1, 2, and 3.

CONCLUSIONS

We observed lower FHP rates and higher cup survival with polyethylene machined from direct compression-molded bar stock, sterilized in argon gas, with barrier packaging.

LEVEL OF EVIDENCE

Level III Therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Therapeutic options in the management of myeloma bone disease

Advanced multiple myeloma is typically accompanied by osteolytic bone lesions resulting from heightened osteolytic activity of osteoclasts and decreased rates of osteogenesis by osteoblasts. Therefore, patients with myeloma bone disease are at increased risk for skeletal-related events (SREs) such as pathologic fracture, the need for radiotherapy or surgery to bone, spinal cord compression, and hypercalcemia of malignancy. Each of these can reduce patients' functional independence, quality of life, and survival. Radiotherapy and surgery are often used to palliate bone pain and to stabilize, repair, or prevent bone fractures. Bisphosphonates (BPs) may reduce the risk of SREs. In particular, clodronate, pamidronate, and zoledronic acid (ZOL) have demonstrated efficacy for delaying the onset of potentially life-threatening SREs. Overall, BPs have a well established tolerability profile. The introduction of BPs for multiple myeloma was practice-changing, and patients now experience far fewer serious fractures and hypercalcemia of malignancy. Ongoing studies will help further refine and optimize the timing and duration of BP therapy in patients with myeloma bone disease.

Cementless total hip arthroplasty for primary osteoarthritis in patients aged 55 years and older

BACKGROUND

Cemented total hip arthroplasty has been the treatment of choice for elderly patients with osteoarthritis. We analyzed survival rates of the most common cementless designs used in this age group in Finland.

PATIENTS AND METHODS

Inclusion criteria permitted 10,310 replacements (8 designs) performed in patients aged 55 years or older to be selected for evaluation. The risk of revision of each of the 8 implants was compared with that of a group comprising 3 cemented designs as the reference (9,549 replacements). Survival analyses were performed overall and separately for 3 age cohorts: 55-64 years (6,781 replacements), 65-74 years (8,821 replacements), and 75 years or older (4,257 replacements).

RESULTS

In all patients aged 55 years or more, the Bi-Metric stem had a higher survival rate for aseptic loosening at 15 years than the cemented reference group: 96% (95% CI: 94-98) vs. 91% (CI: 90-92). However, the 15-year survival rates of the Bi-Metric/Press-Fit Universal (71% (CI: 67-75)) and the Anatomic Mesh/Harris-Galante II (72% (CI: 67-78)) total hip replacements were lower than that of the reference group (86% (CI: 84-87)). Information was scarce for patients aged 75 years or more.

INTERPRETATION

Cementless proximal porous-coated stems are a good option for elderly patients. Even though biological fixation is a reliable fixation method in THA, polyethylene wear and osteolysis remain a serious problem for cementless cup designs with unplugged screw holes and low-quality liners.

The management of spinal metastases from renal cell carcinoma

INTRODUCTION

Osseous metastases occur in 50% of patients with renal cell carcinoma; of these, 15% occur in the spine. The treatment options for spinal metastases secondary to renal cell carcinoma are limited. This paper considers the current management options available for spinal metastases secondary to renal cell carcinoma.

PATIENTS AND METHODS

A review of four patients with spinal metastases secondary to renal cell carcinoma.

RESULTS

The presentation of four cases highlighting the current management options for spinal metastases secondary to renal cell carcinoma.

CONCLUSIONS

Historically, spinal metastases from renal cell carcinoma have been poorly managed; however, as the treatment of the primary disease improves, better treatment of the secondary disease is needed. Cement augmentation, used alone for prophylactic stabilisation or in conjunction with a posterior decompression and fixation, provides a useful addition in the management of these patients optimising their chance to remain ambulant, continent, and pain-free.

Cementless total hip arthroplasty in patients with severely dysplastic hips and a previous Schanz osteotomy of the femur: techniques, pitfalls, and long-term outcome

BACKGROUND AND PURPOSE

Historically, a Schanz osteotomy of the femur has been used to reduce limp in patients with severely dysplastic hips. In such hips, total hip arthroplasty is a technically demanding operation. We report the long-term results of cementless total hip arthroplasty in a group of patients who had all undergone a Schanz osteotomy earlier.

PATIENTS AND METHODS

From 1988 through 1995, 68 total hip replacements were performed in 59 consecutive patients previously treated with a Schanz osteotomy. With the cup placed at the level of the true acetabulum, a shortening osteotomy of the proximal part of the femur and distal advancement of the greater trochanter were performed in 56 hips. At a mean of 13 (9-18) years postoperatively, we evaluated these patients clinically and radiographically.

RESULTS

The mean Harris hip score had increased from 51 points preoperatively to 93 points. Trendelenburg sign was negative and there was good or slightly reduced abduction strength in 23 of 25 hips that had not been revised. There were 12 perioperative complications. Only 1 cementless press-fit porous-coated cup was revised for aseptic loosening. However, the 12-year survival rate of these cups was only 64%, as 18 cups underwent revision for excessive wear of the polyethylene liner and/or osteolysis. 6 CDH femoral components had to be revised due to technical errors.

INTERPRETATION

Our results suggest that cementless total hip arthroplasty combined with a shortening osteotomy of the femur and distal advancement of the greater trochanter can be recommended for most patients with a previous Schanz osteotomy of the femur. Because of the high incidence of liner wear and osteolysis of modular cementless cups in this series, nowadays we use hard-on-hard articulations in these patients.

Prosthetic joint replacement for long bone metastases: analysis of 154 cases

INTRODUCTION

Metastatic bone disease is the most common cause of malignancies to the skeleton in adults. The treatment of bone metastases is frequently palliative aiming to achieve a satisfactory control of pain and to prevent or to treat pathological fractures. In selected cases the resection of a single bone metastasis may improve the survival of the patients. Our experience with bone metastases located in the appendicular skeleton, between 1992 and 2004, is retrospectively reviewed here.

MATERIALS AND METHODS

We report a series of 154 patients (95 females and 59 males) treated with prosthesis for metastatic bone disease. Lower limb localization was more frequent with 117 cases, while upper limb was affected in 37 cases. Metastatic breast and renal carcinoma predominated and accounted for 66% of the lesions. Indications to surgery were reported, oncologic outcome was evaluated and functional results were obtained by the Musculoskeletal Tumor Society scoring system.

RESULTS

Follow up ranged from 6 months to 12 years (median 26 months). One-year survival was 69.5%, 2-years survival was 44.8%, 5-years survival was 19.5%; and 5 (3.2%) died in the early post surgical period. Functional results were good or higher in 73.8% of patients for the proximal femur, in 50% of patients for the knee and 30.6% of patients for the proximal humerus.

CONCLUSION

In this series, satisfactory results were achieved with few complications. We emphasized the importance of giving the patient a definitive treatment and preventing pathological fractures as they determine disability and a spreading of the tumor in the soft tissues, leading to an increased probability of local recurrence. Prosthetic replacement contributes to an improved quality of life and limb functionality and, in selected cases; this radical surgical approach is indicated as it may improve patient's life expectancy.

The Bimetric cementless total hip replacement: 7-18 year follow-up assessing the influence of acetabular design on survivorship

The purpose of this study was to evaluate the mid- to long-term survivorship of Bimetric cementless total hip replacement and assess how it is affected by the acetabular design. This was a retrospective analysis of 127 Bimetric cementless total hip replacements in 110 patients with a follow-up of 7-18 years. A single design stem and three different cementless metal-backed acetabular designs were used. Patients were assessed clinically using the Harris hip score and radiologically by independent review of current hip radiographs. There was only one case of aseptic loosening of the femoral stem. The earliest acetabular design showed a high failure rate whilst the latter two designs showed a 96% survivorship at a mean of 9.5 years. We conclude that a combination of the bimetric stem with either of the latter acetabular cup designs has a good mid- to long-term performance.

Proximal femoral endoprosthesis for the treatment of metastatic

Traditional reconstructive options may not always be adequate to treat the extensive bone loss that can occur with metastatic disease of the proximal femur. Another method of treatment is resection of the proximal femur and reconstruction with an endoprosthesis. However, the more extensive surgery raises concern for a higher perioperative complication rate in this potentially medically unstable population. This study reviewed 57 patients with metastatic disease treated with 58 proximal femoral endoprostheses. The only perioperative complications were 2 symptomatic deep venous thromboses. Late complications included 3 dislocations, 2 deep venous thromboses, 1 pulmonary embolism, and 4 infections. Three deaths occurred during the perioperative period, all from underlying cancer. Proximal femoral endoprostheses offer a safe treatment option for patients with extensive metastatic disease.

Modular prostheses in the treatment of proximal humerus metastases: review of 40 cases

Background

The humerus is the second most common site of metastatic bone disease involving long bones. Tumors which have a predilection for dissemination to bone are those of breast, prostate, thyroid, lung and kidney. The rationale for surgical treatment of these lesions is to prevent or treat pathological fractures in order to relieve pain and improve function.

Materials and methods

Forty patients who had resection of the proximal humerus for metastatic bone disease and reconstruction with a modular prosthesis were retrospectively reviewed.

Results

Mean functional outcome was 73.1% (Enneking score) and better results were achieved when a reverse prosthesis was implanted. Overall survival was 70% at 1 year, 42.5% at 2 years and 20% at 5 years. Local recurrence occurred in 4 patients, each of whom had initially been treated for a pathological fracture.

Conclusions

It is important to follow rational guidelines, like those of Capanna and Mirels, in order to prevent pathological fractures and to give the patient a definitive treatment, as the advances in the management of cancer prolong the survival of these patients. In this series, satisfactory results were obtained, giving the patients an acceptable quality of life.

Surgical management of metastatic disease of the proximal femur

PURPOSE

To review the surgical treatment for metastatic disease of the proximal femur.

METHODS

Records of 8 patients who underwent endoprosthetic replacement with tumour resection (group 1) and 8 others who underwent intramedullary nailing without tumour resection (group 2) were reviewed. Treatments were based on the disease progression and patient's condition.

RESULTS

In groups 1 and 2, the respective mean survival periods were 16 and 4 months. All patients in group 1 regained preoperative mobility, but only one patient in group 2 was able to walk with crutches.

CONCLUSION

This was a retrospective, rather than comparative study of endoprothetic replacement and intramedullary nailing for metastatic disease of the proximal femur. Both procedures are considered palliative, and not curative. The longer survival period in group 1 was mainly due to selection of patients with better preoperative medical status.

Intramedullary nailing for pathological femoral fractures

PURPOSE

To evaluate whether the operating time correlates with the survival and outcome in patients who underwent intramedullary nailing for metastatic femoral fractures.

METHODS

Records of 10 men and 11 women aged 43 to 86 (mean, 66) years who underwent intramedullary nailing (4 bilaterally) for metastatic femoral fractures between 1999 and 2003 were reviewed. The patients were followed up for at least 2 years or until their death. The main outcome measure was the correlation between operating time and survival. Operating time was categorised into 5 groups from 60 to 210 minutes, with 30-minute increments.

RESULTS

Operating time does not correlate with survival and outcome. The mean survival period was 9.4 months. Pain relief was achieved in 90% of the patients. There was no implant failure, but one loss of reduction.

CONCLUSION

Intramedullary nailing appears safe and effective for treatment of metastatic bone disease, and confers good functional results, pain relief, and mobility.

Metastatic bone disease: a 36-year single centre trend-analysis of patients admitted to a tertiary orthopaedic surgical department

BACKGROUND AND OBJECTIVES

The treatment and outcome of primary malignant bone tumours has changed with the advances in diagnostic and treatment modalities. A trend-analysis on a large cohort of patients with metastatic bone disease was performed.

METHODS

A retrospective chart review of all cases with metastatic bone disease admitted to a single tertiary orthopaedic referral centre, registered with the Vienna Bone and Soft Tissue Tumour Registry between 1968 and 2003 was conducted. For trend-analysis of frequency, survival, primary site, treatment methods, and others, the 36-year study duration was divided into four periods.

RESULTS

The study identified 601 females and 580 males (mean: 60 years) with metastatic bone disease. The most common metastases were secondary to breast cancer (n = 275; 23%) and renal cell carcinoma (n = 242; 21%) and the majority were located in the femur (n = 332; 28%) and spine (n = 348; 29%). Overall, the proportion of patients who underwent surgery decreased. At follow-up, 887 (75%) patients were verified to have died of their disease.

CONCLUSIONS

Over the 36-year period, the frequency of bone metastases has increased at our centre. Although survival increased over time, the difference was not significant; this was most likely attributable to the seriousness of cases referred to our tertiary care centre.

Outcomes of an anatomically based approach to metastatic disease of the acetabulum

Metastatic disease of the acetabulum is a common and challenging surgical problem. We asked whether acetabular reconstruction for metastatic bone disease improves functional outcome with an acceptable risk of surgical morbidity. We also asked if primary tumor type and the presence of visceral metastases predicted patient survival. We analyzed prospectively accumulated records of 62 consecutive patients who underwent 63 hip arthroplasties with acetabular reconstruction. Operative technique was guided by the extent of dome and column involvement. Demographics, functional status in the form of the Eastern Cooperative Oncology Group (ECOG) score, and survival data were analyzed. Functional scores improved from an average of 2.6 preoperatively to 1.1 postoperatively. Four patients had postoperative complications for which we performed further surgery. Mean survival for the patients with breast cancer was longer at 21 months compared to 9 months for the patients with other primary malignancies. Patients who did not present with visceral metastases had longer survival than those with visceral metastases. Despite the moderate risk of operative complications, an anatomically based approach to reconstruction of acetabular defects from metastatic disease improves functional outcome. Breast cancer as the primary malignancy and the absence of visceral metastases predicted longer survival.

Lower limb salvage surgery: modular endoprosthesis in bone tumour treatment

We retrospectively analysed 90 patients who underwent "en bloc" resection and modular endoprosthesis reconstruction in the lower limbs between 1987-2003. After proximal femur resection, reconstruction was performed with a modular endoprosthesis by Howmedica (KFTR, designed by Kotz) and modular revision endoprosthesis by W. Link or Lima-Lto (Revision system, designed by Wagner). The knee joint was reconstructed with a modular endoprosthesis (Howmedica, KFTR designed by Kotz) after distal femur or proximal tibia resection. Malignant bone tumours were present in 58 patients (64.5%), benign tumours in 16 (17.8%), metastases in 8 (8.9%), tumour-like lesions in 4 (4.4 %) and non-tumour-related destruction of the femur in 4 patients (4.4%). High-grade tumours were found in the majority of malignant bone tumours (70.7%). Treatment complications, which occurred in 26 patients, were: local recurrence of the tumour, deep infection, acetabular destruction following hemiarthroplasty, recurrent dislocations of endoprosthesis, periprosthetic fracture and hardware problems. In total, 23 patients (25.6%) died due to tumours. Endoprostheses should be considered as a treatment of choice for bone tumours in the hip and knee joint region. Advances in limb salvage surgery are, and will long continue to be, a great challenge for orthopaedic oncologists of the 21st century.

Surgery for metastatic renal cell cancer

Renal cell carcinoma (RCC) often presents in its metastatic form, or progresses after curative treatment. While the management of metastatic RCC has historically been mainly surgical, contemporary approaches often incorporate systemic immunotherapy. This review examines the current indications and scope of surgical treatment of patients with metastatic RCC. Surgery is sometimes indicated for symptom palliation at either the primary or secondary sites. However, other less invasive therapies may be equally effective, and should be considered carefully. Cytoreductive surgery prior to immunotherapy appears to confer a survival advantage, but only selected patients are suitable for this treatment regimen. Primary immunotherapy followed by surgical removal of the tumour in partial responders is an alternative treatment strategy, which has not yet been evaluated as in randomized trials. As immunotherapy develops further, the precise timing and role of surgery in multimodality treatment will need to be carefully evaluated. Occasionally, the complete surgical excision of metastases, and the primary tumour, if present, is feasible and this may prolong survival. Empirically, it would seem that such patients should also be treated with adjuvant immunotherapy, as eventual relapse is frequent. Surgery with the aim of inducing spontaneous tumour regression is not justifiable, given the rarity of this phenomenon.

Myeloma bone disease: pathophysiology and management

Bone disease is a major feature of multiple myeloma. Myeloma-induced bone destruction is the result of an increased activity of osteoclasts, which is not accompanied by a comparable increase of osteoblast function. Recent studies have revealed that new molecules such as the receptor activator of nuclear factor-kappa B (RANK), its ligand (RANKL), osteoprotegerin (OPG), and macrophage inflammatory protein-1alpha are implicated in osteoclast activation and differentiation, while proteins such as dickkopf-1 inhibit osteoblastic bone formation. These new molecules seem to interfere not only with the biology of myeloma bone destruction but also with tumour growth and survival, creating novel targets for the development of new antimyeloma treatment. Currently, bisphosphonates play a major role in the management of myeloma bone disease. Clodronate, pamidronate and zoledronic acid are the most effective bisphosphonates in symptomatic myeloma patients. Biochemical markers of bone remodeling have been used in an attempt to identify patients more likely to benefit from early treatment with bisphosphonates. Furthermore, using microarray techniques, myeloma patients may be subdivided into molecular subgroups with certain clinical characteristics, such as propensity for lytic lesions that may need early prophylactic treatment. Recent phase I studies with recombinant OPG and monoclonal antibodies to RANKL appear promising.