Nicole L. Levine

Background/Objectives: Locally recurrent osteosarcoma is associated with high patient morbidity and mortality, yet the risk factors for local recurrence remain incompletely understood. Therefore, the objective of this study was to comprehensively assess the impact of tumor histology, patient demographics, surgical resection, and chemotherapy delivery on the risk of local recurrence, development of metastases, and overall patient survival in osteosarcoma. Methods: This single-center retrospective review included 102 patients with skeletal osteosarcoma who underwent primary surgical resection between August 2001 and August 2021. Primary outcomes included the development and timing of local recurrence following primary resection. Data was abstracted from the electronic medical record, and statistical analyses were performed to identify demographic, tumor, or management (surgical and chemotherapy) related factors associated with an increased risk of local recurrence. Results: Locally recurrent osteosarcoma developed in 13.7% (n = 14) of patients after primary resection. Patients with local recurrence were more likely to have the chondroblastic subtype (57.1% versus 19.3% in those without local recurrence, p = 0.005). The chondroblastic subtype was associated with shorter local recurrence-free survival and overall survival than other histologic subtypes (p < 0.001). Resection approach, surgical margin status, histologically assessed response to neoadjuvant chemotherapy, and type and dose intensity of chemotherapy delivered were not statistically associated with risk of local recurrence. Conclusions: Chondroblastic histology is a risk factor for local recurrence in osteosarcoma and is associated with poor overall survival in our patient cohort.

Background: Chondrosarcoma is the second most common bone tumor in adults with an average incidence of 0.1–0.3 individuals per 100,000 per year. These tumors are often resistant to chemotherapy and radiation, and surgical excision is a mainstay of current treatment. However, survival in the setting of metastatic disease is still poor, and research is needed to identify prognostic biomarkers and potential therapeutic targets. Several studies have examined the role of IDH mutations in chondrosarcoma, but the results vary widely. The goal of this analysis was to aggregate individual patient data from these studies and conduct a high-powered analysis of the impact of IDH mutations on survival outcomes in chondrosarcoma. Methods: Chondrosarcoma studies that included data on the IDH mutation status of tumors were queried, and the individual datasets reporting patient and tumor variables were extracted. The data from these studies were added to the internal dataset from the authors’ home institution. Two-sample tests for equality of proportions were used to assess the distribution of sample characteristics between groups. Univariate Kaplan–Meier (KM) curves and multivariate Cox Proportional Hazards (CPH) models were used to assess the relationship between tumor IDH mutations and five and ten-year patient overall survival (OS). Results: The final cohort included 1152 patients sourced from 21 studies and the authors’ internal dataset. IDH mutations were more common in higher grade tumors and were more likely to be found in individuals over 60 years old. Patients with IDH mutant tumors had shorter five-year OS in univariate KM analysis when analyzing all chondrosarcomas combined. However, multivariate CPH models accounting for age and tumor grade, found that the effect of IDH mutation was isolated to patients with dedifferentiated tumors only. Patients with IDH mutant dedifferentiated tumors displayed significantly shorter five-year OS (HR: 1.99, p = 0.02) relative to patients with IDH wild-type (WT) dedifferentiated tumors. The primary predictor of five-year OS in the conventional chondrosarcoma cohort was tumor grade, regardless of IDH mutation status (HR: 2.72, p < 0.005). Discussion: IDH mutations are relatively common in cartilaginous neoplasms (including benign tumors), with the literature reporting rates as high as 50% in chondrosarcomas. Prior studies have investigated the link between IDH1/2 mutation status, tumor grade and overall survival, with mixed results on the effect of IDH mutation on survival. Vuong et al. performed a meta-analysis in 2021 and found that IDH mutation was associated with older patient age, larger tumor size, higher tumor grade, and increased risk of death compared to WT tumors. Our analysis, which builds on the Vuong et al. study, indicates that IDH status itself is not independently predictive of overall survival in conventional chondrosarcoma, however, it does correlate with survival in dedifferentiated tumors. Further analysis is needed to investigate the potential correlation of IDH mutations in higher grade tumors and patients of older age.

Background: Percutaneous tripod fixation of periacetabular lesions is performed at our institution for patients with metastatic bone disease and a need for quick return to systemic therapy. We have begun to use the IlluminOss Photodynamic Bone Stabilization System instead of the metal implants previously described in the literature because of the success of the IlluminOss implant in fixing fragility fractures about the pelvis. Description: At our institution, the procedure is performed in the interventional radiology suite in order to allow for the use of 3D radiographic imaging and vector guidance systems. The patient is positioned prone for the transcolumnar PSIS-to-AIIS implant and posterior column/ischial tuberosity implant or supine for the anterior column/superior pubic ramus implant. Following a small incision, a Jamshidi needle with a trocar is utilized to enter the bone at the chosen start point. A hand drill is utilized to advance the Jamshidi needle according to the planned vector; alternatively, a curved or straight awl can be utilized. The 1.2-mm guidewire is placed and reamed. We place both the transcolumnar and posterior column wires at the same time to ensure that there is no interference. The balloon catheter for the IlluminOss is assembled on the back table and inserted according to the implant technique guide. The balloon is inflated and observed on radiographs in order to ensure that the cavity is filled. Monomer is then cured, and the patient is flipped for the subsequent implant. Following placement of the 3 IlluminOss devices, adjunct treatments such as cement acetabuloplasty or cryoablation can be performed. Alternatives: Alternative treatments include traditional open fixation of impending or nondisplaced acetabular fractures in the operating room, or percutaneous implant placement in the operating room. Implant placement may be performed with the patient in the supine, lateral, or prone position, depending on surgeon preference. Alternative implants include standard metal implants such as plates and screws, or cement augmentation either alone or with percutaneous screws. Finally, ablation alone may be an alternative option, depending on tumor histology. Rationale: Open treatment of acetabular fractures is a more morbid procedure, given the larger incision, increased blood loss, longer time under anesthesia, and increased length of recovery. Percutaneous fixation may be performed in either the operating room or interventional radiology suite, depending on the specific equipment setup at an individual institution. At our institution, we prefer utilizing the interventional radiology suite as it allows for more precise implant placement through the use of an image-based vector guidance system and 3D fluoroscopy to accurately identify safe corridors. The use of percutaneous fixation allows for faster recovery and earlier return to systemic therapy. Because the IlluminOss implant is radiolucent, it allows for better evaluation of disease progression and can better accommodate nonlinear corridors or fill a lytic lesion to provide stability. Expected Outcomes: Postoperatively, we expect the patient to be weight-bearing as tolerated with use of an assistive device. We expect the small incisions to fully heal within 2 weeks. Patients should be able to return to systemic therapy as indicated earlier than with an open procedure. Important Tips: The use of a hand drill with the Jamshidi needle and trocar can help adjust a drilled pathway and allow for close adherence to a planned vector. Vector guidance systems can be useful to fully capture the area at risk for fracture and to provide maximal stability with the expandable implant, but they are not necessary to perform the procedure. Placing both posterior implants at the same time can be helpful to avoid interference. This is accomplished by drilling and placing the guidewire for both implants prior to reaming and placing the balloon implant. Acronyms and Abbreviations: CT = Computed tomography PSIS = posterior superior iliac spine AIIS = anterior inferior iliac spine

Study Design.: We performed a comprehensive search of PubMed, MEDLINE, and EMBASE for all English language studies of all levels of evidence pertaining to Spine Patient Outcomes Research Trial (SPORT), in accordance with Preferred Reported Items for Systematic Reviews and Meta-analyses guidelines. Objective.: We aim to summarize the 10-year clinical outcomes of SPORT and its numerous follow-up studies for degenerative spondylolisthesis. Summary of Background Data.: The SPORT was a landmark randomized control trial including approximately 2500 patients at 13 clinics across the country. SPORT compared surgical and nonoperative management of the three most common spinal pathologies. Methods.: Keywords used in the literature search included SPORT, spine patient outcomes research trial, degenerative spondylolisthesis, and surgical outcomes. Results.: The intent-to-treat analysis failed to show a significant difference between patients treated surgically as compared to those treated nonoperatively. However, as-treated analysis revealed statically greater improvements at 6 weeks, 2 years, and 4 years in patients treated surgically. Secondary outcomes such as low back pain, leg pain, stenosis bothersome scales, overall satisfaction with current symptoms, and self-rated progress were also significantly improved in surgical patients. Regardless of the initial grade of listhesis, disk height, or mobility, patients who had surgical treatment improved more in terms of Oswestry Disability Index, bodily pain, physical function, and low back pain bothersomeness scales. Risk of reoperation increased with age, having two or three moderate or severe stenotic levels, pain predominantly localized to the back, no physical therapy, the absence of neurogenic claudication, and greater leg pain scores. Risk of reoperation was not significantly affected by type of surgery performed, smoking, diabetes, obesity, longer duration of symptoms, or workman's compensation. Conclusion.: Although intent-to-treat analysis failed to show significant differences in patients treated surgically, results of the as-treated analysis determined statically greater improvements in those patients with spondylolisthesis who were treated surgically as compared to those treated nonoperatively. Level of Evidence: 2