Cross-cultural adaptation, reliability, and validity of the Russian version of the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0).

OBJECTIVE: The most validated health-related quality-of-life (HRQOL) questionnaire specific to the metastatic spine cancer population is the Spine Oncology Study Group Outcomes Questionnaire version 2 (SOSGOQ2.0). The purpose of this study was to translate and validate a Russian version of the SOSGOQ2.0. METHODS: The SOSGOQ2.0 was translated into Russian and cross-culturally adapted. In this study, 64 eligible patients completed the SOSGOQ2.0_RUS along with the EQ-5D 5 Level, SF-36 quality-of-life questionnaires, and visual analog scale for pain assessment scale (VAS). Internal consistency was measured using Cronbach's alpha, in which a score of 0.65 or higher is acceptable. Test-retest reliability was evaluated by examining the intraclass correlation coefficient (ICC). RESULTS: Included in this study were 64 Russian-speaking patients (median age 59 years) with metastatic spine disease. The most common primary tumors were breast, kidney, and prostate cancers. The overall Cronbach's alpha was 0.87, indicating high internal consistency. The overall ICC for the SOSGOQ2.0_RUS was 0.88 (95% CI 0.81-0.93), indicating high reliability and consistency of the measure. The physical function, pain, and mental health domains of the SF-36 moderately correlated with the same domains of the SOSGOQ2.0_RUS, with correlation coefficients ranging from 0.65 to 0.71. CONCLUSIONS: The SOSGOQ2.0_RUS is a reliable and valid questionnaire for assessing the HRQOL in patients with metastatic spinal tumors. The questionnaire showed high internal consistency, test-retest reliability, and good construct validity when compared with other established questionnaires.

Improved functional status in patients undergoing cement and rebar reconstruction with total hip arthroplasty for uncontained metastatic tumors of the acetabulum.

BACKGROUND AND OBJECTIVE: Metastatic cancer of the acetabulum can produce marked pain and disability for patients. Several reconstruction techniques for such lesions have been described, with variable outcomes. The purpose of this study was to determine functional outcomes and complication rate for patients undergoing cement rebar reconstruction using posterior column screws with total hip arthroplasty for large, uncontained lesions of the acetabulum. METHODS: Twenty-two consecutive patients who underwent cement rebar reconstruction with posterior column screws and total hip arthroplasty for metastatic tumors of the acetabulum between 2014 and 2017 were identified. All cases were reviewed for patient demographics, surgical parameters, implant survival, complications, and functional status following these procedures. RESULTS: There was a significant increase in the proportion of patients able to ambulate post-surgery (95.5%) compared with presurgery (22.7%) (p < 0.001). Mean musculoskeletal tumor society score postoperatively was 17.9 (60%). Average operative time was 174 min and average estimated blood loss was 689 mL. Seven patients required an intraoperative or postoperative blood transfusion. Three patients had postoperative complications (14%), two of whom required revision (9%). CONCLUSION: Reconstruction using cement rebar with posterior column screws and total hip arthroplasty is a safe, reproducible approach that may greatly improve functional outcomes with a low rate of intraoperative or postoperative complications.

Conditional survival after surgery for metastatic tumors of the spine: does prognosis change over time?

PURPOSE: Conditional survival (CS) provides a dynamic prediction of patient survival by incorporating the time an individual has already survived given their disease specific characteristics. The objective of the current study was to estimate CS among patients after surgery for spinal cord compression or spinal instability, as well as stratify CS according to relevant patient- and disease-related characteristics. METHODS: The clinical outcomes of 361 patients undergoing surgical management of metastatic spinal tumors were retrospectively analyzed. Stratification of this cohort according to disease and surgery-specific characteristics allowed for univariate and multivariate statistical analyses of our study population. Observed overall and conditional survival estimates were calculated by the Kaplan-Meier method. RESULTS: 12-month conditional survival in patients undergoing surgical management of metastatic spine tumors increased from 57% at baseline to 70% at 24 months following spine surgery. Overall survival (OS) was influenced by CCI grade, Katagiri tumor type, presence of lung metastasis, type of spine surgery, presence of postoperative systemic therapy and ambulatory status at follow-up. Analyses of OS and CS by prognostic strata were similar with exception of stratification by surgery type. Differences in survival between strata tend to converge over time. Unfavorable factors for OS appear to be less relevant after a period of 24 months following spine surgery. CONCLUSION: Patients after surgery for metastatic tumors of the spine can expect a positive trend in conditional survival as survivorship increases. Even patients with a more severe disease can be encouraged with gains in conditional survival over time. LEVEL OF EVIDENCE: Level IV (retrospective cohort study).

Hardware Failure in Spinal Tumor Surgery: A Hallmark of Longer Survival?

OBJECTIVE: Instrumentation failure in spine tumor surgery is a common reason for revision operation. Increases in patient survival demand a better understanding of the hardware longevity. The study objective was to investigate risk factors for instrumentation failure requiring revision surgery in patients with spinal tumors. METHODS: A retrospective cohort from a single tertiary care specialty hospital from January 2005 to January 2021, for patients with spinal primary or metastatic tumors who underwent surgical intervention with instrumentation. Demographic and treatment data were collected and analyzed. Kaplan-Meier analysis was performed for overall survival, and separate univariate and multivariate regression analysis was performed. RESULTS: Three hundred fifty-one patients underwent surgical intervention for spinal tumor, of which 23 experienced instrumentation failure requiring revision surgery (6.6%). Multivariate regression analysis identified pelvic fixation (odds ratio [OR], 10.9), spinal metastasis invasiveness index (OR, 1.11), and survival of greater than 5 years (OR, 3.6) as significant risk factors for hardware failure. One- and 5-year survival rates were 57% and 8%, respectively. CONCLUSION: Instrumentation failure after spinal tumor surgery is a common reason for revision surgery. Our study suggests that the use of pelvic fixation, invasiveness of the surgery, and survival greater than 5 years are independent risk factors for instrumentation failure.

Are Skin Fiducials Comparable to Bone Fiducials for Registration When Planning Navigation-assisted Musculoskeletal Tumor Resections in a Cadaveric Simulated Tumor Model?

BACKGROUND: To improve and achieve adequate bony surgical margins, surgeons may consider computer-aided navigation a promising intraoperative tool, currently applied to a relatively few number of patients in whom freehand resections might be challenging. Placing fiducials (markers) in the bone, identifying specific anatomical landmarks, and registering patients for navigated resections are time consuming. To reduce the time both preoperatively and intraoperatively, skin fiducials may offer an efficient and alternative method of navigation registration. QUESTIONS/PURPOSES: (1) Does preoperative navigation using skin fiducials for registration allow the surgeon to achieve margins similar to those from bone fiducial registration in a simulated lower extremity tumor resection model in cadavers? (2) Does the use of preoperative navigation using skin fiducials for registration allow the surgeon to achieve similar bony margins in pelvic resections of simulated tumors as those achieved in long-bone resections using only skin fiducials for navigation in a cadaver model? METHODS: Simulated bone tumor resections were performed in three fresh-frozen cadavers with intact pelvic and lower-extremity anatomy using navigation guidance. We placed 5-cm intraosseous cement simulated bone tumors in the proximal/distal femur (n = 12), and proximal/distal tibia (n = 12) and pelvis (supraacetabular; n = 6). After bone tumor implantation, CT images of the pelvis and lower extremities were obtained. Each planned osseous resection margin was set at 10 mm. Navigation registration was performed for each simulated tumor using bone and skin markers that act as a point of reference (fiducials). The simulated bone tumor was resected based on a resection line that was established with navigation, and the corresponding osseous margins were calculated after resection. These margins were determined by an orthopaedic surgeon who was blinded to resection planning by the removal of cancellous bone around the cement simulated tumor. The shortest distance was measured from the cement to the resection line. Smaller mean differences between planned and postoperative margins were considered accurate. Independent t-tests were conducted to assess measurement differences between planned and postoperative margins at the 95% CI. Bland-Altman analyses were conducted to compare the deviation in margin difference between planned and postoperative margins in skin and bone fiducial registration, respectively. RESULTS: In all, 84 total resection margins were measured with 48 long bone and 20 pelvic obtained with skin fiducials and 16 long bone obtained with bone fiducials. The planned mean margin was 10 mm for all long bone and pelvic resections. We found that skin fiducial and bone fiducial postoperative margins had comparable accuracy when resecting long bones (10 ± 2 mm versus 9 ± 2 mm, mean difference 1 [95% CI 0 to 2]; p = 0.16). Additionally, skin fiducial long bone postoperative margins were comparable in accuracy to pelvic supraacetabular postoperative margins obtained with skin fiducials (10 ± 2 mm versus 11 ± 3 mm, mean difference -1 mm [95% CI -3 to 1]; p = 0.22). When comparing the deviation in margin difference between planned and postoperative margins in skin and bone fiducial registration, 90% (61 of 68) of skin fiducial and 100% (16 of 16) bone fiducial postoperative margins fell within 2 SDs. CONCLUSIONS: In this pilot study, skin fiducial markers were easy to identify on the skin surface of the cadaver model and on CT images used to plan margins. This technique appears to be an accurate way to plan margins in this model, but it needs to be tested thoroughly in patients to determine if it may be a better clinical approach than with bone fiducials. CLINICAL RELEVANCE: The margins obtained using skin fiducials and bone fiducials for registration were similar and comparable in this pilot study with a very small effect size. Boundaries of the simulated tumors were not violated in any resections. Skin fiducials are easier to identify than bone fiducials (anatomic landmarks). If future clinical studies demonstrate that margins obtained using skin fiducials for registration are similar to margins obtained with anatomical landmarks, the use of navigation with skin fiducials instead of bone fiducials may be advantageous. This technique may decrease the surgeon's time used to plan for and localize registration points and offer an alternative registration technique, providing the surgeon with other registration approaches.

MRI Identification of the Osseous Extent of Pediatric Bone Sarcomas.

BACKGROUND: The quantitative accuracy of MRI in predicting the intraosseous extent of primary sarcoma of bone has not been definitively confirmed, although MRI is widely accepted as an accurate tool to plan limb salvage resections. Because inaccuracies in MRI determination of tumor extent could affect the ability of a tumor surgeon to achieve negative margins and avoid local recurrence, we thought it important to assess the accuracy of MR-determined tumor extent to the actual extent observed pathologically from resected specimens in pediatric patients treated for primary sarcomas of bone. QUESTIONS/PURPOSES: (1) Does the quantitative pathologic bony margin correlate with that measured on preoperative MRI? (2) Are T1- or T2-weighted MRIs most accurate in determining a margin? (3) Is there a difference in predicting tumor extent between MRI obtained before or after neoadjuvant chemotherapy and which is most accurate? METHODS: We retrospectively studied a population of 211 potentially eligible patients who were treated with limb salvage surgery between August 1999 and July 2015 by a single surgeon at a single institution for primary sarcoma of bone. Of 131 patients (62%) with disease involving the femur or tibia, 107 (51%) were classified with Ewing's sarcoma or osteosarcoma. Records were available for review in our online database for 79 eligible patients (37%). Twenty-six patients (12%) were excluded because of insufficient or unavailable clinical or pathology data and 17 patients (8%) were excluded as a result of inadequate or incomplete MR imaging, leaving 55 eligible participants (26%) in the final cohort. The length of the resected specimen was superimposed on preresection MRI sequences to compare the margin measured by MRI with the margin measured by histopathology. Arithmetic mean differences and Pearson r correlations were used to assess quantitative accuracy (size of the margin). RESULTS: All MR imaging types were positively associated with final histopathologic margin. T1-weighted MRI after neoadjuvant chemotherapy and final histopathologic margin had the strongest positive correlation of all MR imaging and time point comparisons (r = 0.846, p < 0.001). Mean differences existed between the normal marrow margin on T1-weighted MRI before neoadjuvant chemotherapy (t = 8.363; mean, 18.883 mm; 95% confidence interval [CI], 14.327-23.441; p < 0.001), T2-weighted MRI before neoadjuvant chemotherapy (t = 8.194; mean, 17.204 mm; 95% CI, 12.970-21.439; p < 0.001), T1-weighted after neoadjuvant chemotherapy (t = 10.808; mean, 22.178 mm; 95% CI, 18.042-26.313; p < 0.001), T2-weighted after neoadjuvant chemotherapy (t = 10.702; mean, 20.778 mm; 95% CI, 16.865-24.691; p < 0.001), and the final histopathologic margin. T1-weighted MRI after neoadjuvant chemotherapy compared with the final histopathologic margin had the smallest mean difference in MRI-measured versus histopathologic margin size (mean, 5.9 mm; SD = 4.5 mm). CONCLUSIONS: T1 MRI after neoadjuvant chemotherapy exhibited the strongest positive correlation and smallest mean difference compared with histopathologic margin. When planning surgical resections based on MRI obtained after neoadjuvant chemotherapy, for safety, one should account for a potential difference between the apparent margin of a tumor on an MRI and the actual pathologic margin of that tumor of up to 1 cm. LEVEL OF EVIDENCE: Level III, diagnostic study.