Artificial intelligence assisted preoperative planning and 3D-printing guiding frame for percutaneous screw reconstruction in periacetabular metastatic cancer patients.

Background: The percutaneous screw reconstruction technique, known as the "Tripod Technique," has demonstrated favorable clinical outcomes in the management of metastatic periacetabular lesions, as evidenced by our prior investigations and corroborated by independent studies. Nevertheless, there is a steep learning curve in handling this technique, with possible complications such as intraarticular screw placement. Methods: Preoperative pelvic CT scans were acquired before surgery and utilized for the guiding frame design. A convolutional neural network model was trained with annotated data to identify the starting point and trajectory of each potential screw. A model boundary intersection detection technology was used to determine the optimal diameter and length of each screw. A non-rigid registration technology was matched with a prefabricated model of the body surface to design personalized anchoring skin pads. Finally, a polylactic acid-based guiding frame for intraoperative was custom-made with a 3D printer. Results: 12 patients underwent a guiding frame-assisted Tripod procedure for treatment of periacetabular metastatic lesions. An intraoperative CT scan was performed in all cases to confirm screw trajectories. Among 36 screws that were implanted, 26 screws were implanted as designed. The remaining ten screws drifted, but all remained within the intra-osseous conduit without any complications. The mean surgical time was 1.22 h with the guiding frame compared with 2.3 h without the guiding frame. Following the surgical procedure, a noteworthy enhancement in pain management, as evidenced by a reduction in scores on the visual analog scale (p < 0.01), and an improvement in functional status, as assessed through the Eastern Cooperative Oncology Group score (p < 0.01), were observed when compared to the patient's pre-operative condition. Conclusion: This proof-of-concept investigation demonstrates that the amalgamation of AI-assisted surgical planning and additive manufacturing can improve surgical accuracy and shorten surgical duration. While access to this technology is currently constrained during its early stages of development, it is anticipated that these limitations will diminish as the potential of AI and additive manufacturing in facilitating complex orthopedic procedures becomes more evident, leading to a surge in interest and adoption of this approach.

Novel candidate metastasis-associated genes for synovial sarcoma.

Synovial sarcoma (SS) is an aggressive soft tissue sarcoma with poor prognosis due to late recurrence and metastasis. Metastasis is an important prognostic factor of SS. This study aimed to identify the core genes and mechanisms associated with SS metastasis. Microarray data for GSE40021 and GSE40018 were obtained from the Gene Expression Omnibus database. 186 differentially expressed genes (DEGs) were identified. The biological functions and signalling pathways closely associated with SS metastasis included extracellular matrix (ECM) organization and ECM-receptor interaction. Gene set enrichment analysis showed that the terms cell cycle, DNA replication, homologous recombination and mismatch repair were significantly enriched in the metastasis group. Weighted gene co-expression network analysis identified the most relevant module and 133 hub genes, and 31 crossover genes were identified by combining DEGs. Subsequently, four characteristic genes, EXO1, NCAPG, POLQ and UHRF1, were identified as potential biomarkers associated with SS metastasis using the least absolute shrinkage and selection operator algorithm and validation dataset verification analysis. Immunohistochemistry results from our cohort of 49 patients revealed visible differences in the expression of characteristic genes between the non-metastatic and metastatic groups. Survival analysis indicated that high expression of characteristic genes predicted poor prognosis. Our data revealed that primary SS samples from patients who developed metastasis showed activated homologous recombination and mismatch repair compared to samples from patients without metastasis. Furthermore, EXO1, NCAPG, POLQ and UHRF1 were identified as potential candidate metastasis-associated genes. This study provides further research insights and helps explore the mechanisms of SS metastasis.

The clinical effectiveness and safety of Zone III REBOA for resection of sacropelvic tumors in patients older than 70 years.

BACKGROUND: REBOA is a method used to manage bleeding during surgery involving sacropelvic tumors. Nevertheless, studies on the use of REBOA among elderly people are lacking. The aim of this research was to investigate the efficacy and safety of Zone III REBOA in patients aged more than 70 years. METHODS: A comparative study was conducted using case-control methods. A group of patients, referred to as Group A, who were younger than 70 years was identified and paired with a comparable group of patients, known as Group B, who were older than 70 years. Continuous monitoring of physiological parameters was conducted, and blood samples were collected at consistent intervals. RESULTS: Totally, 188 participants were enrolled and received REBOA. Among the 188 patients, seventeen were aged more than 70 years. By implementing REBOA, the average amount of blood loss was only 1427 ml. Experiments were also conducted to compare Group A and Group B. No notable differences were observed in terms of demographic variables, systolic blood pressure (SBP), arterial pH, lactate levels, blood creatinine levels, potassium levels, or calcium levels at baseline. Additionally, after the deflation of the REBOA, laboratory test results, which included arterial pH, lactate, potassium concentration, calcium concentration, and blood creatinine concentration, were not significantly different (P > 0.05). CONCLUSION: This study indicated that in selected patients aged more than 70 years can achieve satisfactory hemodynamic and metabolic stability with Zone III REBOA. LEVEL OF EVIDENCE: Therapeutic study, Level III.

Hierarchical self-recognition and response in CSC and non-CSC micro-niches for cancer therapy.

Cancer stem cells (CSCs) characterized by self-renewal, invasiveness, tumorigenicity and resistance to treatment are regarded as the thorniest issues in refractory tumors. We develop a targeted and hierarchical controlled release nano-therapeutic platform (SEED-NPs) that self-identifies and responds to CSC and non-CSC micro-niches of tumors. In non-CSC micro-niche, reactive oxygen species (ROS) trigger the burst release of the chemotherapeutic drug and photosensitizer to kill tumor cells and reduce tumor volume by combining chemotherapy and photodynamic therapy (PDT). In CSC micro-niche, the preferentially released differentiation drug induces CSC differentiation and transforms CSCs into chemotherapy-sensitive cells. SEED-NPs exhibit an extraordinary capacity for downregulating the stemness of CD44+/CD24- SP (side population) cell population both in vitro and in vivo, and reveal a 4-fold increase of tumor-targeted accumulation. Also, PDT-generated ROS promote the formation of tunneling nanotubes and facilitate the divergent network transport of drugs in deep tumors. Moreover, ROS in turn promotes CSC differentiation and drug release. This positive-feedback-loop strategy enhances the elimination of refractory CSCs. As a result, SEED-NPs achieve excellent therapeutic effects in both 4T1 SP tumor-bearing mice and regular 4T1 tumor-bearing mice without obvious toxicities and eradicate half of mice tumors. SEED-NPs integrate differentiation, chemotherapy and PDT, which proved feasible and valuable, indicating that active targeting and hierarchical release are necessary to enhance antitumor efficacy. These findings provide promising prospects for overcoming barriers in the treatment of CSCs.

Clinical outcomes in patients with neurological disorders following periacetabular tumor removal and endoprosthetic reconstruction of the hemipelvis.

Background: Surgical treatment of musculoskeletal tumors in the periacetabular region present extremely difficult due to the complex anatomy and need for reconstruction. Orthopedic surgeons face more difficulties in patients with neurological conditions, which can cause increased muscle tone, an elevated risk of fractures, and compromised bone quality. There is limited evidence regarding endoprosthetic reconstruction for periacetabular tumors in individuals with neurological disorders. Methods: We conducted a single-center retrospective study to examine the outcomes of patients with preexisting neurological conditions who underwent surgery to remove periacetabular tumors and who underwent endoprosthesis reconstruction. Clinical presentation, detailed neurological conditions, complications, and functional outcomes were studied. Results: Sixteen out of the 838 patients were identified (1.91%), with a mean follow-up time of 33 months. The primary neurological conditions encompassed Parkinson's disease, Alzheimer's disease, dementia, and cerebral ischemic stroke. Every patient was diagnosed with periacetabular lesions that were either primary or oligometastatic. They underwent tumor resection and subsequently received endoprosthetic reconstruction of the hemipelvis. Three patients developed metastasis lesions later, and two patients experienced tumor recurrence. Five cases experienced hip dislocation-one with periprosthetic fracture and one with surgical site infection. The position of the prosthetic rotating center was not correlated with dislocation. The reoperation rate was 31.25%. The cohort of patients all presented with more extended hospital stays and rehabilitation. In 3 patients, the general functional score was good, while in 6 patients, it was fair; in 7 patients, it was regarded as poor. The average MSTS93 score was 49.71%. Conclusion: Endoprosthetic reconstruction after periacetabular tumor resection is an effective way to eliminate tumors and salvage limbs. However, this group of patients has an increased likelihood of secondary surgery, complications, extended hospital stay, and no significant improvement in functional outcomes. Despite the diverse nature of the cohort, it is recommended to consider enhanced soft tissue reconstruction, supervised functional recovery and rehabilitation training.

The outcomes of proximal femur replacement with hemiarthroplasty after tumor resection in individuals with Parkinson's disease.

Background: Patients with neurological disorders often experience a high incidence of postoperative complications following proximal femur replacement (PFR) surgery. The orthopaedist faces a significant difficulty in treating Parkinson's disease (PD) because of the weakened bone condition, excessive muscle tension, and increased risk of fractures. The objective of this research is to assess the impact of PD on PFR following tumor removal. Methods: A retrospective study was conducted from 2010 to 2020, focusing on a solitary institution, analyzing 9 patients diagnosed with PD who underwent PFR with hemiarthroplasty as a result of tumor removal. The study consists of 2 men and 7 women, with an average age of 71 (SD, 12) years. We assessed the outcomes after surgery in terms of pain management, quality of life, functional ability, occurrence of complications, and survival durations. Results: All nine patients underwent planned surgeries. Intraoperative complications was not observed. The average length of the follow-up period was 24 (SD, 20) months, ranging from 8 to 72 months. Despite the fact that 8 patients passed away due to tumor progression, the endoprostheses were still well at that point. The preoperative VAS score of 7 (SD, 1.87) decreased to a postoperative score of 2 (SD, 1.32). The KPS was improved to73 (SD, 7) from 52 (SD, 14), postoperatively. Post-surgery, there were notable enhancements in both pain levels and the overall quality of life scores. Following the surgical procedure, individuals are able to ambulate steadily, resuming their regular daily routines. Living patients had an average MSTS score of 21 (SD, 2.5), ranging from 17 to 25. In total, there were four (44.4%) patients suffered complications after surgery, comprising of one wound dehiscence, one prosthetic fracture, one hip dislocation, and one local recurrence. Conclusions: Significant improvements in function and pain relief can be achieved through PFR with hemiarthroplasty following tumor removal in patients with PD. The implementation of thorough preparation and carefull nursing results in reduced complications and improved outcomes in PD patients.

Surgical results and quality of life after single-stage posterior transpedicular approach for circumferential epidural decompression in patients with thoracolumbar spine metastasis.

Objective: The primary aim of this study was to evaluate the effect of palliative surgery using posterior transpedicular approach (PTA) with posterior instrumentation on pain response and quality of life (QoL) in patients with metastatic thoracic and lumbar tumors. Methods: From 2018 to 2019, 39 patients with metastatic thoracic and/or lumbar tumors were prospectively enrolled to measure the reduction in pain and the changes in QoL after surgical decompression with posterior instrumentation via PTA. The patient group was composed of 27 men and 12 women with a mean age of 60 years (range, 28 to 92 years). Pain response was measured using the visual analog scale (VAS) and neurologic status was evaluated using Frankel grades. QoL was assessed with use of the EORCT QLQ-BM22 questionnaire before surgery (baseline) and at 1-, 3-, 6-, and 12-month after surgery. The survival times of all the patients were also collected. Results: All patients showed either an improvement or a similar pain level after surgery, which the VAS score decreased from 7.10 ± 2.22 preoperatively to 3.10 ± 2.15 one month postoperatively (P<0.05). 19 patients (48.7%, 19/39) showed neurological function improvement postoperatively. Among the 19 patients, 7 cases improved from Frankel grade C to D, 5 cases from grade C to E, and 7 cases from grade D to E. Another 20 patients still have the same Frankel grade postoperatively, however, most of them improved clinically. The QoL improvement of the patients was also evident after treatment. Paired-samples T-test examination of the postoperative scores showed a significant improvement in terms of pain location, pain severity and performance status (P<0.01). Compared with the preoperative score, the 1-month postoperative score of functional interference was significantly improved (63.6 vs. 34.5, P<0.01). There were no significant changes in social or psychological functioning. Three patients experienced cerebrospinal fluid leakage postoperatively, and they were all successfully managed by lying flat without a pillow. One patient experienced rod breakage, at 10 months after surgery. All the patients were alive at 3 months; however, 7 patients died within 3 to 6 months, and another 9 patients died from the disease within 6 to 12 months. Conclusions: The present feasibility study found that the application of the PTA for decompression and fusion in patients with spinal metastases is beneficial for achieving prompt and sustained pain relief, reducing neurologic deficits and improving functional outcomes, health utilities, and HRQoL.

Indocyanine green fluorescence imaging may detect tumour residuals during surgery for bone and soft-tissue tumours.

The aim of this study was to determine the rate of indocyanine green (ICG) staining of bone and soft-tissue tumours, as well as the stability and accuracy of ICG fluorescence imaging in detecting tumour residuals during surgery for bone and soft-tissue tumours. ICG fluorescence imaging was performed during surgery in 34 patients with bone and soft-tissue tumours. ICG was administered intravenously at a dose of 2 mg/kg over a period of 60 minutes on the day prior to surgery. The tumour stain rate and signal-to-background ratio of each tumour were post hoc analyzed. After tumour resection, the tumour bed was scanned to locate sites with fluorescence residuals, which were subsequently inspected and biopsied. The overall tumour stain rate was 88% (30/34 patients), and specific stain rates included 90% for osteosarcomas and 92% for giant cell tumours. For malignant tumours, the overall stain rate was 94%, while it was 82% for benign tumours. The ICG tumour stain was not influenced by different pathologies, such as malignant versus benign pathology, the reception (or lack thereof) of neoadjuvant chemotherapies, the length of time between drug administration and surgery, the number of doses of denosumab for patients with giant cell tumours, or the tumour response to neoadjuvant chemotherapy. The overall accuracy rate of successfully predicting tumour residuals using fluorescence was 49% (23/47 pieces of tissue). The accuracy rate after en bloc resection was significantly lower than that after piecemeal resection (16% vs 71%; p < 0.001). A high percentage of bone and soft-tissue tumours can be stained by ICG and the tumour staining with ICG was stable. This approach can be used in both benign and malignant tumours, regardless of whether neoadjuvant chemotherapy is adopted. The technique is also useful to detect tumour residuals in the wound, especially in patients undergoing piecemeal resection.

Outcomes of Fixed-Hinged Knee Prosthesis for Distal Femoral Osteosarcoma in Skeletally Immature Patients: First Results.

The best surgical choice for distal femur osteosarcoma in skeletally immature patients remains controversial. A fixed hinged knee prosthesis has been designed to preserve the growth plates in the adjacent tibia, expecting tibial growth to be continued. This study aims to report the (1) clinical outcomes after prosthetic replacement, (2) postoperative complications, and (3) length of discrepancy of the operative tibia with the unaffected tibia. Thirty-four skeletally immature patients (averaged 9 years at surgery; range, 5-12 years) with distal femoral osteosarcoma underwent placement of this hinged knee prosthesis between January 2015 and August 2018. Postoperative function and complications were assessed. Length discrepancy was measured using a series of full-length standing anteroposterior radiographs of the bilateral lower extremity. The average follow-up duration was 34 months (2.8 years). In the last follow-up, four patients expired because of pulmonary metastasis. Two patients presented with local recurrence of the soft tissue. Postoperatively, the flexion range of the knee joint range was between 100 and 130 degrees, with an average of 115.2 degrees. The mean functional score of living patients evaluated using the Musculoskeletal Tumor Society scoring system was 89.2% (range, 76.7-100%). Types 1 (three patients), 2 (one patient), 3 (two patients), and 5 (two patients) complications exist. Among them, three patients received revision surgery. The proximal tibial physis still grew after surgery, with an average of 74.3% (range, 30-100%) growth potential compared with the unaffected proximal tibial physis. Moreover, 27 children exhibited tibial length discrepancy compared with the contralateral tibia, and the mean discrepancy in tibial length was 1.1 cm (range, 0.2-3.1 cm). This hinged knee prosthesis can keep the growth potential in the adjacent tibia, provides satisfying functional outcomes, and has a lower postoperative complication rate. Thus, it could serve as an alternative intervention for distal femoral osteosarcoma in skeletally immature patients.

The COPS3-FOXO3 positive feedback loop regulates autophagy to promote cisplatin resistance in osteosarcoma.

Chemotherapy is an important treatment modality for osteosarcoma (OS), but the development of chemoresistance limits the therapeutic efficacy of OS and results in a poor prognosis. Thus, a better understanding of the mechanisms underlying chemoresistance in OS is essential. We previously demonstrated that COPS3/CSN3 (COP9 signalosome subunit 3) functions as an oncogene to promote OS cells lung metastasis, which is closely related to chemoresistance. Here, we showed that COPS3 was significantly upregulated in OS tissues with poor response to preoperative chemotherapy. Moreover, COPS3 depletion made OS cells more sensitive to cisplatin treatment in vitro and in vivo, implicating COPS3 as a driver of cisplatin resistance. Mechanistic investigations showed that COPS3 induced a cytoprotective macroautophagy/autophagy in response to cisplatin. Specifically, we identified FOXO3 as a critical target of COPS3, as high expression of COPS3 enhanced the nuclear abundance of FOXO3 and increased the expression of FOXO3-responsive genes, promoting autophagosome formation and maturation. In turn, FOXO3 regulated COPS3 levels by inhibiting ubiquitin-mediated degradation and attenuating SKP2-mediated COPS3 inhibition, cooperatively maintaining a high level of COPS3. In both COPS3-expressing OS cells and a murine xenograft model, inhibition of autophagy could also overcome resistance to cisplatin. Collectively, our results offer insights into the mechanisms of cisplatin resistance and suggest that targeting COPS3-mediated autophagy is a promising therapeutic strategy for overcoming the cisplatin resistance of OS.Abbreviations: 3-MA: 3-methyladenine; BECN1: beclin 1; ChIP: chromatin immunoprecipitation; CHX: cycloheximide; COPS3/CSN3: COP9 signalosome subunit 3; CQ: chloroquine; DEGs: differentially expressed genes; FOXO3: forkhead box O3; GFP: green fluorescent protein; IC50: 50% inhibitory concentration; LAMP1: lysosomal associated membrane protein 1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MTOR: mechanistic target of rapamycin kinase; mRFP: monomeric red fluorescent protein; OS: osteosarcoma; PBS: phosphate-buffered saline; qRT-PCR: quantitative real-time PCR; RAB7: RAB7, member RAS oncogene family; RPS6KB1/p70S6K1: ribosomal protein S6 kinase B1; SEM: standard error of the mean; shRNA: short hairpin RNA; siRNA: small interfering RNA; SKP2: S-phase kinase associated protein 2; TEM: transmission electron microscopy; UPS: ubiquitin-proteasome system.

Association between intraoperative fluid overload and postoperative debridement in major sacrum tumor resection: A propensity score matching study.

Intra-aortic balloon occlusion (IABO) is used to reduce intraoperative bleeding and facilitate successful sacrum tumor resection. Up to 20% of patients experience postoperative wound healing problems, but the risk factors related to this complication have not been clearly defined. The anesthetic database of Peking University People's Hospital, Beijing, China, was searched for all patients (aged 14-70 years old) who underwent sacrum tumor surgery with the application of IABO from 2014 to 2017. Data from 278 patients with an aortic occlusion duration of 72 ± 33 minutes were collected. Fifty-six patients required postoperative debridement because of wound infection. The independent risk factor identified by logistic regression was fluid excess (calculated as volume infused minus blood loss and urine output divided by body weight [kg]), and decision tree analysis revealed that the cutoff point for fluid excess was 38.5 mL/kg. Then patients were then divided into high fluid excess group (fluid excess > 38.5 mL/kg) and low fluid excess group (fluid excess ≤ 38.5 mL/kg) and 91 pairs of patients were generated through propensity score matching (PSM). Fluid excess was significantly higher in the high fluid excess group (46 vs 30 mL/kg, P < .001), and more patients required postoperative debridement than in the low fluid excess group (24 (26.3%) vs 12 (13.1%), P < .001). In this retrospective PSM study on sacrum tumor resection, fluid overload was related to postoperative debridement and further studies are needed to improve the clinical prognosis.

Molecular subtypes of osteosarcoma classified by cancer stem cell related genes define immunological cell infiltration and patient survival.

Recent studies have shown that tumor stemness has biological significance in tumorigenicity and tumor progression. However, the characteristics of TME immune infiltration in osteosarcoma mediated by the combined effects of multiple cancer stem cell-related genes remain unknown. Methods: In this study, we identified different cancer stem cell-associated subtypes in osteosarcoma based on 25 cancer stem cell-associated genes by consensus clustering analysis, and we comprehensively evaluated the association between these subtypes and immunocytes infiltration in the TME. The cancer stem cell (CSC) score was constructed to quantify the stemness of individual tumors. Results: We performed a comprehensive evaluation of 218 osteosarcoma patients based on 25 cancer stem cell-related genes. Three different cancer stem cells related subtypes were identified, which were related to different biological processes and clinical outcomes. The three subtypes have different TME cells infiltrating characteristics, and CSC Cluster A had a higher level of immunocyte infiltration compared to CSC Cluster B and C. We constructed a scoring system, called the CSC score, to assess the stemness of individual patients. Then we found that the prognosis of patients was predicted by CSC score, and patients with low CSC score had prolonged survival. Further analyses showed that low CSC score was correlated with enhanced immune infiltration. CSC score may predict the effect of immunotherapy, and patients with low CSC score may have better immune response and clinical prognosis. Conclusions: This study demonstrates that there could be three cancer stem cell-associated subtypes in osteosarcoma and that they were associated with different patient prognosis and TME immune infiltration characteristics. CSC score could be used to assess the stemness of individual patients, improve our comprehension of TME characteristics, and direct more effective immune therapy.

Reconstruction With a 3D-Printed Megaprosthesis With Ankle Arthrodesis After Distal Tibial Tumor Resection.

BACKGROUND: Reconstruction after en bloc resection of the distal tibia has remained an unsettled issue despite many attempts with bone grafts or prostheses in the past. Failures of the previous methods have been attributed to inadequate mechanical strength, poor articular stability, failed osseointegration, and poor soft tissue coverage. To overcome these shortcomings, we designed and applied a 3D-printed megaprosthesis with ankle arthrodesis. METHODS: A total of 13 patients underwent resection of a distal tibial tumor and reconstruction with a 3D-printed distal tibial megaprosthesis between January 2017 and November 2020. Mean age was 14.9±6.5 years. Diagnoses included 11 cases of osteosarcoma and 1 case each of low-grade phosphaturic mesenchymal tumor and rhabdomyosarcoma. Baseline characteristics, operative data, complication profiles, and oncologic, and functional outcomes were reviewed and analyzed. RESULTS: All 13 cases attained a wide or marginal resection. During a mean follow-up of 26.8±10.6 months, 1 patient experienced local recurrence and distant metastasis, whereas 3 other patients only developed distant metastasis. Periprosthetic infection subsequent to paronychia occurred in 1 patient 24 months after the operation. No other complications were observed. By the last follow-up, the mean MSTS-93 score was 28.0±1.5. CONCLUSION: In this relatively small cohort with short-term follow-up, reconstruction with the 3D-printed megaprosthesis with ankle arthrodesis was found to be a safe and efficacious method after resection of a distal tibial malignancy.

Catastrophic Periprosthetic Osteolysis in Total Hip Arthroplasty at 20 Years: A Case Report and Literature Review.

BACKGROUND: Periprosthetic osteolysis is a serious complication following total hip arthroplasty (THA). However, most orthopedic surgeons only focus on bone loss and hip reconstruction. Thus, it was required to understand the treatment algorithm for periprosthetic osteolysis integrally. CASE PRESENTATION: A 52-year-old Asian male presented with chronic hip pain. A mass appeared on the medial side of the proximal left thigh at more than 20 years after bilateral THA. Radiographs revealed catastrophic periprosthetic osteolysis, especially on the acetabular side. Large amounts of necrotic tissue and bloody fluids were thoroughly debrided during revision THA. A modular hemipelvic prosthesis was used for revision of the left hip. Four years later, the patient presented with right hip pain, where a mass appeared on the medial side of the proximal right thigh. A primary acetabular implant with augment was used for revision of the right hip. Laboratory evaluation of bloody fluid retrieved from surgery revealed elevated levels of inflammatory markers. CONCLUSION: Inflammatory responses to polyethylene wear debris can lead to severe bone resorption and aseptic loosening in the long-term following THA. Therefore, in spite of revision THA, interrupting the cascade inflammatory might be the treatment principle for periprosthetic osteolysis.

Efficacy and safety of a 3D-printed arthrodesis prosthesis for reconstruction after resection of the proximal humerus: preliminary outcomes with a minimum 2-year follow-up.

BACKGROUND: The purpose of this study was to investigate the feasibility of using a three-dimensional (3D)-printed arthrodesis prosthesis for reconstruction of the proximal humeral defect after tumor resection. METHODS: A novel proximal humeral prosthesis was designed to restore bone continuity and shoulder arthrodesis and was fabricated via 3D printing technology. Ten patients with primary malignancies in the proximal humerus underwent intra-articular resection and replacement with this prosthesis from 2017 to 2019. Baseline and operative data, oncological and prosthetic survival, and functional status were summarized. RESULTS: This cohort consisted of 9 males and 1 female with a mean age of 32.1 ± 16.1 years. Diagnoses included 5 cases of osteosarcoma, 3 cases of chondrosarcoma and 1 each case of undifferentiated pleomorphic sarcoma and malignant myoepithelioma. The mean operative duration, intraoperative hemorrhage and postoperative length of hospitalization were 151.5 ± 61.0 min, 410.0 ± 353.4 ml and 5.3 ± 1.9 d, respectively. The mean follow-up duration was 29.3 ± 6.4 months, with a minimum of 24 months for the surviving patients. Two patients experienced local recurrence, and four patients developed distant metastases. Detachment of the taper occurred in two patients. One was managed conservatively, and the other received amputation due to concurrent tumor recurrence. The mean MSTS-93 and ASES scores and ranges of forwards flexion and abduction were 24.9 ± 3.1, 79.4 ± 8.3, 71.3 ± 19.4°, and 61.3 ± 16.4°, respectively. The functional outcomes were independent of the preservation of the axillary nerve. Histological study of the glenoid component showed evidence of bone ingrowth at the bone-prosthesis porous interface. CONCLUSION: Application of the 3D-printed arthrodesis prosthesis might be a safe and efficacious method for functional reconstruction in patients who underwent resection of the proximal humerus, especially for those without preservation of the axillary nerve.

A clinical study of the hemodynamic and metabolic effects of Zone 3 REBOA for sacral and pelvic tumor resections.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a key procedure in sacral and pelvic tumor resection that provides hemorrhage control. However, few studies have been performed to capture the effects of REBOA in a nonshock condition and provide a detailed description of the changes occurring with prolonged occlusion time. This study aimed to examine the hemodynamic and metabolic effects of Zone 3 REBOA for sacral and pelvic tumor resections following different periods of REBOA. METHODS: In total, 121 patients who underwent surgical tumor resections of the pelvis and/or the sacrum with the use of aortic balloon occlusion were prospectively enrolled from October 2020 to December 2021. All cases were divided into Group A (occlusion time ≤ 60 min, n = 57) and Group B (occlusion time ≥ 90 min, n = 64). Physiologic parameters were continuously recorded, and laboratory specimens were obtained at regular intervals. RESULTS: Balloon inflation resulted in a significant increase in SBP from 106 to 120 mmHg and decreased to 96 mmHg immediately following balloon deflation. With the application of REBOA, the median blood loss was only 1200 ml (range, 400-7900). When deflating the REBOA, the arterial pH was lower than baseline (7.36 vs. 7.41, p < 0.01), the arterial lactate concentration increased from 0.9 to 1.4 mmol/L (p < 0.01), serum potassium measurements increased from 3.99 to 4.12 mmol/L, serum calcium measurements decreased from 2.31 to 2.04 mmol/L, and blood creatinine decreased from 64 to 60 µmol/L. The operating time of Group B was longer than that of patients in Group A, and the patients in Group B needed more blood units to be transfused. Although laboratory measurements, including pH, potassium, calcium, and blood creatinine, were at the same level in two groups comparison, the lactate was significantly higher in Group B after deflation (p = 0.01). CONCLUSIONS: The results of this study showed that acceptable hemodynamic and metabolic stability can be attained when the occlusion time of REBOA is more than 90 min, although the long duration of occlusion caused relatively higher lactate levels.

Factors associated with spinal fixation mechanical failure after tumor resection: a systematic review and meta-analysis.

BACKGROUND: No available meta-analysis has been published that systematically assessed spinal fixation mechanical failure after tumor resection based on largely pooled data. This systematic review and meta-analysis aimed to investigate the spinal fixation failure rate and potential risk factors for hardware failure. METHODS: Electronic articles published between January 1, 1979, and January 30, 2021, were searched and critically evaluated. The authors independently reviewed the abstracts and extracted data on the spinal fixation failure rate and potential risk factors. RESULTS: Thirty-eight studies were finally included in the meta-analysis. The pooled spinal fixation mechanical failure rate was 10%. The significant risk factors for hardware failure included tumor level and cage subsidence. Radiotherapy was a potential risk factor. CONCLUSION: The spinal fixation mechanical failure rate was 10%. Spinal fixation failure is mainly associated with tumor level, cage subsidence and radiotherapy. Durable reconstruction is needed for patients with these risk factors.

Analysis for clinical feature and outcome of chondroblastoma after surgical treatment: A single center experience of 92 cases.

BACKGROUND: Chondroblastoma is a rare, benign, cartilaginous bone tumor derived from epiphyseal chondrocytes. Although the clinical characteristics and experience of surgical treatment of the smaller number of patients has been reported in the literature, it is difficult to draw conclusions about the clinical and radiographic features and the outcome for surgical treatment of this disease due to the rarity of chondroblastoma. This study was aiming to review the epidemiologic characteristics and outcome of surgical management for patients with chondroblastoma. METHODS: We performed a retrospective analysis of 92 patients with chondroblastoma. Clinical data, radiographic images, surgical treatment and outcome were analyzed. Eighty-two patients received the extensive intralesional curettage and ten cases had the En-block resection. RESULTS: The most common site of disease was proximal femur (20.7%, 19/92), followed by distal femur (18.5%, 17/92) and proximal tibia (16.3%, 15/92). The secondary aneurysmal bone cyst component was most common for chondroblastoma of the small irregular bones, such as patella and foot. Four (4.3%, 4/92) cases receiving the extensive intralesional curettage developed the local recurrence, respectively two at the proximal tibia, one at the pelvis and one at the calcaneus. Time to local recurrence were respectively 14.5, 8.8, 27.0 and 5.6 months, with the average 14 months. Kaplan-Meier estimated survivorship curve of local recurrence-free survival rates of one, two and five years were respectively 97.7%, 96.2% and 93.9%. The mean Musculoskeletal Tumor Society (MSTS) score was 29.4. At the last follow-up, no one had the pulmonary metastasis and death associated with the disease. CONCLUSION: Intralesional curettage plus local adjuvants can obtain satisfactory outcome for chondroblastoma. LEVEL OF EVIDENCE: Level IV.

Ultra-Short Course of Neo-Adjuvant Denosumab for Nerve-Sparing Surgery for Giant Cell Tumor of Bone in Sacrum.

STUDY DEIGN: This was a retrospective study about sacral giant cell tumor of bone (GCTB). OBJECTIVE: This study aimed to investigate whether ultra-short course of neo-adjuvant denosumab treatment for sacral GCTB could (1) induce radiological and histological response? (2) Facilitate nerve-sparing surgery? (3) Achieve satisfactory oncological and functional outcomes? SUMMARY OF BACKGROUND DATA: Previous reports on long course of neo-adjuvant denosumab treatment for GCTB showed significant tumor response and a relatively high recurrent rate after curettage. METHODS: Sixty-six patients with sacral GCTB treated with neoadjuvant denosumab and nerve-sparing surgery were categorized into ultra-short course group (≤3 doses and operation within D21 since 1st dose, 41 patients) or conventional group (>3 doses or operation after D21 since 1st dose, 25 patients). The radiological and histological response, operative data, oncological and functional outcomes were compared. RESULTS: The ultra-short course group demonstrated fewer doses of neo-adjuvant denosumab (mean: 2.1 vs. 4.8, P  < 0.001) and shorter time to surgery (12.2 days vs. 72.3 days, P < 0.001). Similar patterns of radiological and histological response were observed in the two groups with less fibrosis and ossification in the ultra-short course group. The operative duration (199.9 min vs. 187.8 min, P = 0.364) and estimated blood loss (1552.4 mL vs. 1474.0 mL, P = 0.740) were comparable. Most (94.8%) of the patients received adjuvant denosumab. After a mean follow-up of 29.4 months, three cases (8.8%) and five cases (20.8%) showed local recurrence in each group (P = 0.255). The estimated recurrence-free survival (56.2 vs. 51.2 months, P = 0.210) and the functional status [Motor-Urination-Defecation scores: 25.9 vs. 25.7, P = 0.762] did not differ between the two groups. CONCLUSION: Ultra-short course of neo-adjuvant denosumab for sacral GCTB could elicit radiological and histological responses as conventional course did. The less degree of fibrosis and ossification might facilitate nerve-sparing surgery and help to achieve satisfactory local control and functional status.Level of Evidence: 4.

Surgical treatment of benign osteolytic lesions in the femoral head and neck: a systematic review.

BACKGROUND AND OBJECTIVES: Treatment of benign osteolytic lesions in the femoral head and neck can be extremely challenging, particularly in children with open physis or for aggressive tumors with pathological fracture. There remains the difficult management decision as to whether to perform complete excision of the involved area or only curettage. Moreover, there is no agreed consensus on the optimal approach to lesion access when performing curettage, which included the transcervical, open and direct approach. The current systematic review aims to provide guidance for selection of surgical methods in clinical practice by comparing the advantages and drawbacks of different procedures. METHODS: A comprehensive literature search of PubMed, Embase and Web of Science databases were executed for human studies restricted to the English language. The search was filtered to include studies published from January 1980 to January 2020. RESULTS: A total of 33 articles including 274 patients were enrolled in the final analysis. The most common diagnosis was chondroblastoma (CBT) (104, 38.0%), followed by giant cell tumor (GCT) (56, 20.4%). There were 57 (20.8%) patients with pathological fracture. Intralesional curettage was performed in 257 (93.8%) patients with the local recurrence of 12.5% at the mean follow-up of 51.5 months. The patients who were presented with open physis or curetted via transcervical approach developed higher local recurrence in patients with CBT (P < 0.001). The local recurrence rate of GCT is 33.3% after curettage, while 8 of 9 (88.9%) patients with fracture were treated successfully with joint preservation. Two of 45 (4.4%) patients developed avascular necrosis (AVN) of femoral head after surgical hip dislocation. The reported Musculoskeletal Tumor Society (MSTS) Score was comparable among patients with different approaches to curettage. CONCLUSION: The majority of benign osteolytic lesions in the femoral head and neck can be treated with intralesional curettage with acceptable local tumor control and satisfactory function. The incidence of local recurrence might be decreased dramatically for lesion access under direct visualization. The native joint maintenance could be achieved even in patients with aggressive lesions presenting pathological fracture.