Surgery combined with anlotinib for local control of patients with resectable extremity desmoid fibromatosis: a retrospective study.

Background: Desmoid fibromatosis (DF) is a pathological intermediate fibroblastoma that is difficult to control locally due to its invasive nature, especially in the extremities. Although anlotinib demonstrated efficacy in treating DF with tolerable safety, the impact of surgical intervention in conjunction with anlotinib administration on local control in patients with extremity DF remains undetermined. Methods: We conducted a retrospective examination of the clinical medical documentation belonging to patients with resectable DF of the extremities who were treated with surgery between January 2010 and June 2022. The patients were divided into two cohorts: surgery alone cohort and surgery combined with anlotinib group (surgery plus anlotinib cohort), crossover to surgery plus anlotinib cohort was admissible for patients in the surgery alone cohort who experienced disease recurrence postoperatively. Clinical data such as basic information, tumor location, anlotinib toxicity, time to recurrence, surgical complications, follow-up time, visual analogue scale (VAS) score and Musculoskeletal Tumor Society (MSTS) score at the last follow-up were collected. Results: In total, 48 consecutive patients (19 males and 29 females) with resectable DF of the extremities, including 25 patients in the surgery alone cohort, 23 patients in the surgery plus anlotinib cohort, and 10 patients who were transferred from the surgery alone cohort to the surgery plus anlotinib cohort. The VAS score at the last follow-up was 5 (IQR, 3-6) in the surgery alone cohort and 2 (IQR, 1-3) in the surgery plus anlotinib cohort, respectively; the MSTS score at the last follow-up was 19 (IQR, 16.5-24) in the surgery alone cohort and 27 (IQR, 25-28) in the surgery plus anlotinib cohort, respectively; these characteristics were statistically different between the two cohorts. The 3-year recurrence-free survival (RFS) of the surgery alone cohort and the surgery plus anlotinib cohort were 37.7% and 72.6%, respectively, and the difference was statistically significant (p = 0.022). Conclusion: Surgery combined with anlotinib appears to be effective in controlling local recurrence in patients with resectable DF of the extremities, and the side effects were acceptable.

Comparative study of gait parameters of patients undergoing distal femoral resections with non-operated and healthy limbs: a meta-analysis study.

Introduction: Gait analysis is one of the most important components of functional outcome evaluation in patients with lower-extremity tumors. Disparities between operated limbs when compared with non-operated limbs and healthy populations based on gait parameters have rarely been studied. In the present study, we attempted to analyze the gait difference and its impacts on daily life. Methods: The gait parameters of distal femoral tumor-resected patients were collected from PubMed, CNKI, MEDLINE, Embase, Cochrane, and Google Scholar till September 30, 2022, by strictly following the inclusion and exclusion criteria. Differences between gait parameters in the operated and non-operated limbs or healthy limbs of distal femoral tumor patients were analyzed based on stance phase, swing phase, cadence, and velocity. The fixed-effects and random-effects models were used to conduct a meta-analysis. Results: Six studies were included according to the selection criteria. There were 224 patients in total in these studies. Standard mean differences were calculated for all of our outcomes. Our results showed that there was a minimal difference in the standard mean difference of gait parameters between operated and non-operated limbs and healthy limbs. Conclusion: Distal femoral tumor resections have been associated with deficient muscle function and strength and impaired gait parameters. Minimal differences in the gait parameters highlighted the advantage of distal femoral resection when replaced with a prosthesis.

Preserving the rectus femoris and improving limb function after total femoral prosthesis replacement following resection of femoral malignant tumors.

Background: Current research is focused on the factors that influence the maintenance of limb function after total femoral replacement. This retrospective study investigated the difference in functional outcomes in patients with invasion of the rectus femoris vs. an intact rectus femoris that underwent total femoral replacement with a modular total femur prosthesis. Methods: The medical records of patients who underwent total femoral replacement with a modular total femur prosthesis between July 2010 and March 2017 at our institute were retrospectively reviewed. The patients were divided into two groups: group A had invasion of the rectus femoris and group B had an intact rectus femoris. Functional status was assessed using the Musculoskeletal Tumor Society Rating Scale (MSTS) and the Harris Hip Score (HHS). Complications were assessed using the International Society of Limb Salvage classification that was published in 2011 and modified in 2014. Results: The mean total MSTS score (23.0 ± 4.8 vs. 17.6 ± 3.1; P = 0.02) and the mean total HHS score (80.17 ± 6.24 vs. 55.38 ± 13.30; P = 0.001) were significantly higher in patients with intact rectus femoris compared with patients with invasion of the rectus femoris. Patients with an intact rectus femoris achieved significantly better limb function (support and gait) and active range of motion (P < 0.05). The overall complication rate was 35.7%. Conclusions: Functional outcomes after total femoral replacement were significantly better in patients with an intact rectus femoris compared with patients with invasion of the rectus femoris, possibly because more muscle mass can be preserved around the femur in patients with an intact rectus femoris.

Comparative Study of Proximal Femur Bone Tumor Patients Undergoing Hemiarthroplasty versus Total Hip Arthroplasty: A Meta-Analysis.

Hemiarthroplasty and total hip arthroplasty are routinely performed procedures. A comparison of these procedures in tumor patients can be performed based on complications and functional outcomes. To weigh the advantages and disadvantages of both procedures, a comparative study is indeed required to decide which procedure is more beneficial for primary bone tumor patients. The outcomes of proximal femur tumor-resected patients were collected from research reports from PubMed, MEDLINE, EMBASE, Cochrane, and Google Scholar until 30 December 2022. Differences between these two operative procedures in primary bone tumors patients were analyzed based on dislocation, infection, local recurrence, MSTS, and HHS. Six articles were included according to the selection criteria with a total of 360 patients. Our results showed that there was a significant difference in our primary outcome as hemiarthroplasty participants encountered less dislocation than those with total hip arthroplasty. Moreover, the secondary outcomes of our study were similar. Proximal femur bone tumors, when resected, tend to produce more complications and decrease functional ability due to extensive tumor extension and soft tissue involvement. The lower dislocation rate in hemiarthroplasty participants emphasizes the importance of preserving the acetabular head in hemiarthroplasty as a key to preventing dislocation.

Comparing quality of life in lower extremity tumor patients undergoing limb salvage surgery and amputation: a meta-analysis.

Purpose: Limb salvage surgery and amputation are two commonly performed procedures for lower extremity tumors. When comparing these procedures in tumor patients, it is important to consider their impact on quality of life (QOL) and functional mobility. These patients often experience physical, emotional, and psychological challenges, making these factors crucial in determining the most suitable treatment approach. Method: The outcomes of lower extremity tumors patients for QOL were collected from PubMed, MEDLINE, EMBASE, Cochrane, and Google Scholar until 28 February 2023. The physical function, mental health, role function, social function, emotional function, Toronto Extremity Salvage Score, and Musculoskeletal Tumor Society Score outcomes were analyzed to determine the differences between the two procedures. Results: Five articles were included according to the selection criteria with a total of 245 patients. The standard mean difference (SMD) values of each parameter were slightly higher in limb salvage surgery patients but not higher enough to produce statistically significant results; the SMD values for physical function and mental health were 0.72 and 0.04, respectively. This study did not report any heterogeneity or publication bias. Conclusions: QOL is a large and enhanced term, which carries its importance and is challenging to compare between any procedures. The minimal rise in SMD of different QOL parameters highlighted only a slight advantage of limb salvage surgery over amputation. Therefore, further research is required to explore the impact of this crucial topic.

Case Report: Three-dimensional printed prosthesis reconstruction for patello-femoral large osteochondral defects in a patient with distal femoral giant cell tumour: A case report.

Background: The restoration and reconstruction of patello-femoral large osteochondral defects caused by bone tumours are challenging because of the local recurrence rate and the joint's mechanical complexity. Although three-dimensional (3D)-printed prostheses are commonly adopted for tumour-induced bone defect reconstruction, patello-femoral osteochondral reconstruction with 3D-printed prostheses is rarely reported. Case presentation: A 44-year-old female patient with progressive swelling and pain in the left knee for 6 months was diagnosed with Campanacci Grade II giant cell tumour (GCT). She underwent intralesional curettage combined with autografting and internal fixation, after which complications of deep infection arose. The patient then underwent internal fixation removal and cement packing. Afterwards, the pain of the affected knee persisted for 11 months, and bone cement removal plus 3D-printed modular prosthesis reconstruction was performed. At the last follow-up 27 months after surgery, she was pain free, the Musculoskeletal Tumour Society (MSTS) score improved from 15/30 to 29/30, the Visual Analogue Scale (VAS) score decreased from 7 to 0, and knee flexion increased from 50° to 130°. X-ray images 22 months after surgery showed that the prosthesis and screws were in a stable position, and callus formation was found at the prosthesis-bone interface. Conclusions: A 3D-printed modular prosthesis may be a useful treatment option for the surgical reconstruction of GCT-induced patello-femoral large osteochondral defects. The firm fixation, osseointegration, and favourable congruency of the 3D-printed prosthesis with the adjacent articular surface can achieve long-term knee function and stability.

Comparative study of pelvic sarcoma patients undergoing internal and external hemipelvectomy: A meta-analysis study.

Introduction: Malignant and giant pelvic tumors are complex and rare, and hemipelvectomies are complex procedures performed for this malignant lesion. Only a few studies had been conducted on the survival and recurrence of pelvic sarcomas patients undergoing internal or external hemipelvectomy. In the present study, we compared internal with external hemipelvectomy in pelvic sarcomas on clinical outcomes by a meta-analysis. Methods: The survival and recurrence rates of pelvic sarcomas patients were collected from research reports from CNKI, MEDLINE, EMBASE, the Cochrane Database, and Google Scholar until April 2022. The quality of included articles was evaluated by two independent reviewers. Differences between patients undergoing internal and external hemipelvectomy were analyzed based on postoperative survival and recurrence rates. Results: Five articles were included according to selection criteria. There were 183 patients in total from these studies. Our results showed that there was no significant difference between limb salvage surgery and amputation according to survival; however, patients with internal hemipelvectomy had a lower recurrence rate. Conclusions: Internal hemipelvectomy results in a lower recurrence rate and similar survival rate, while not increasing the risk of metastasis and complications. This study provided more pieces of evidence to support internal hemipelvectomy as a favorable treatment of pelvic sarcomas.

Personalized Surgical Planning for Soft Tissue Sarcoma of the Popliteal Fossa with a Novel 3D Imaging Technique.

OBJECTIVE: Soft tissue sarcomas (STSs) arising from the popliteal fossa pose surgical challenges due to their proximity to critical neurovascular structures. This study aimed to investigate whether a novel 3D imaging technique highlighting these key anatomical structures could facilitate preoperative planning and improve surgical outcomes in STS. METHODS: This was a prospective, observational, pilot study. Between November 2019 and December 2020, 27 patients with STS of the popliteal fossa undergoing limb-sparing procedures were enrolled and assigned to either a control or intervention group. Control patients underwent traditional preoperative planning with separate computed tomography angiography, magnetic resonance imaging, and magnetic resonance hydrography. In the intervention group, 3D images were generated from these images, the tumor and skeletomuscular and neurovascular structures were revealed in three dimensions, and this was visualized on the surgeon's smartphone or computer. Primary endpoints were surgical margins and complications. Secondary endpoints included operative time, blood loss, serum C-reactive protein and interleukin-6, length of in-hospital stay, and limb function. Comparisons between groups were made using independent-sample t-tests for continuous data and the Mann-Whitney U and Fisher's exact tests for categorical data. RESULTS: There was a lower but not significantly different inadvertent positive margin rate (1/15 vs. 3/12, P = 0.294), significantly shorter hospital stay (P = 0.049), and less numbers ≥75th percentile of operative time (P = 0.037) and blood loss (P = 0.024) in the intervention group. Differences in surgical complications, operative time, blood loss, C-reactive protein and interleukin-6 levels on the second postoperative day, and limb functional scores were statistically insignificant. CONCLUSIONS: The novel 3D imaging technique facilitates complex preoperative planning and limb-salvage surgical procedures for patients with STS of the popliteal fossa, and this may affect how surgical planning is performed in the future.

Preoperative Planning Using Three-Dimensional Multimodality Imaging for Soft Tissue Sarcoma of the Axilla: A Pilot Study.

Axillary soft tissue sarcoma (STS) is challenging due to its proximity to vital neurovascular bundles. We conducted a prospective observational pilot study to explore whether 3D multimodality imaging (3DMMI) can improve preoperative planning for and surgical outcomes of patients with axillary STS. Twenty-one patients with STS (diameter > 5 cm) of the axilla were allocated, at their discretion, to either a control group undergoing traditional preoperative planning with separate computed tomography angiography, magnetic resonance imaging, and magnetic resonance neurography, or an intervention group where 3DMMI, digitally created based on these images, revealed the tumour and adjacent skeletomuscular and neurovascular structures in three dimensions. Primary outcome measures were surgical margins and surgical complications. Secondary outcomes included operative time, blood loss, serum C-reactive protein and interleukin-6, length of hospital stay, and limb function. The 3DMMI group had a lower, although not significantly different, inadvertent positive margin rate (1/12 vs. 3/9, p = 0.272), a significantly shorter operative time (p = 0.048), reduced blood loss (p = 0.038), and reduced length of hospital stay (p = 0.046). This endorses larger trials to improve complex surgical procedures and study how preoperative planning could be performed in the future.

Epidemiological Evidence for Associations Between Genetic Variants and Osteosarcoma Susceptibility: A Meta-Analysis.

Background: Previous studies have showed that single nucleotide polymorphisms (SNPs) might be implicated in the pathogenesis of osteosarcoma (OS). Numerous studies involving SNPs with OS risk have been reported; these results, however, remain controversial and no comprehensive research synopsis has been performed till now. Objective: This study seeks to clarify the relationships between SNPs and OS risk using a comprehensive meta-analysis, and assess epidemiological evidence of significant associations. Methods: The PubMed, Web of Science, and Medline were used to screen for articles that evaluated the association between SNP and OS susceptibility in humans before 24 December 2021. Furthermore, we used Venice Criteria and a false positive report probability (FPRP) test to assess the grades of epidemiological evidence for the statistical relationships. Results: We extracted useful data based on 43 articles, including 10,255 cases and 13,733 controls. Our results presented that 25 SNPs in 17 genes were significantly associated with OS risk. Finally, we graded strong evidence for 17 SNPs in 14 genes with OS risk (APE1 rs1760944, BCAS1 rs3787547, CTLA4 rs231775, ERCC3 rs4150506, HOTAIR rs7958904, IL6 rs1800795, IL8 rs4073, MTAP rs7023329 and rs7027989, PRKCG rs454006, RECQL5 rs820196, TP53 rs1042522, VEGF rs3025039, rs699947 and rs2010963, VMP1 rs1295925, XRCC3 rs861539), moderate for 14 SNPs in 12 genes and weak for 14 SNPs in 11 genes. Conclusion: In summary, this study offered a comprehensive meta-analysis between SNPs and OS susceptibility, then evaluated the credibility of statistical relationships, and provided useful information to identify the appropriate candidate SNPs and design future studies to evaluate SNP factors for OS risk.

Correlation analysis of the puncture-side bone cement/vertebral body volume ratio and bone cement leakage in the paravertebral vein in vertebroplasty.

OBJECTIVES: To explore the influencing factors of bone cement leakage in the paravertebral vein after vertebroplasty for the treatment of osteoporotic vertebral compression fractures (OVCFs) and to determine the correlation between the puncture-side bone cement/vertebral body volume ratio and bone cement leakage in the paravertebral vein. METHODS: This was a retrospective analysis of 495 patients (585 vertebral bodies) with OVCFs treated from August 2018 to May 2021 in our hospital. The patients' postoperative CT data were imported into Mimics software, and the three-dimensional(3D) reconstruction function was used to calculate the bone cement volume (BCV), puncture-side bone cement volume (PSBCV), and vertebral body volume (VBV); the bone cement/vertebral body volume ratio (BCV/VCV%) and puncture-side bone cement/vertebral body volume ratio (PSBCV/VCV%) were additionally calculated. Sex, Age, Body mass index(BMI), Bone density, BCV, PSBCV, VBV, BCV/VCV%, and PSBCV/VCV were compared between the leakage group and the non-leakage group. Logistic regression analysis was used to assess the correlations between the factors that statistically significantly differed between the two groups and the presence of leakage in the paravertebral veins. A receiver operating characteristic (ROC) curve was used to determine the diagnostic value of the PSBCV/VCV% and to obtain the optional cut-off value. RESULTS: A total of 102 males and 393 females with an average age of 72.89 (52 ~ 93) years were included in our study. There were 57 cases of cement leakage (59 vertebral bodies) in the paravertebral vein. There were 438 patients (526 vertebral bodies) without paravertebral cement leakage. Univariate analysis showed that the differences in sex, bone density, PSBCV, and PSBCV/VCV% between the two groups were statistically significant (P < 0.05). Logistic regression analysis showed that there were correlations between sex, bone density, and PSBCV/VCV% and the presence of paravertebral cement leakage (P < 0.05). The ROC curve showed that the area under the curve of the PSBCV/VCV% for the diagnosis of cement leakage in the paravertebral vein was greater than 0.65, and P < 0.05, indicating a diagnostic value. The best cut-off point for the diagnosis of paravertebral cement leakage with the PSBCV/VCV% was 13.68%, with a sensitivity of 84.7% and specificity of 37.8%. CONCLUSION: Sex, bone density, and PSBCV/VCV% are risk factors for cement leakage in the paravertebral veins after vertebroplasty for the treatment of OVCFs; the PSBCV/VCV% is strongly associated with paravertebral venous leakage, and the optimal PSBCV/VCV% is 13.68%. When the PSBCV/VCV% exceeds the optimal value, the risk of cement leakage in the paravertebral vein becomes significantly increased.

Cervical arthroplasty versus anterior cervical discectomy in the treatment of symptomatic cervical spondylosis: A protocol.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) are both the effective techniques in treatment of cervical spondylosis. The purpose of this present retrospective cohort research was to assess the efficacy and safety of ACDF and CDA in treating the symptomatic cervical spondylosis over the 6-year follow-up. METHODS: From our registry database, we identified retrospectively patients who received CDA or ACDF in our academic institutions from 2012 to 2015. The study was approved by the Institutional Review Board in Zigong No.4 People's Hospital (Z10058072). All the subjects who participated in this trial were informed consent in writing. The inclusion criteria were the degenerative disc diseases between C3-7 resulting in myelopathy or radiculopathy, which was unresponsive to the conservative treatment. The clinical results were determined via Short Form-36, and neck disability index, numerical scoring scales for complications, arm pain and neck pain. The radiographic assessment contained the cervical lordosis, and the motion range of the functional spinal unit and total cervical spine. The routine follow-up was performed to collect the data of radiographic and clinical assessment at 6, 12, 24, 48, and 72 months before and after the surgery. RESULTS: This study had limited inclusion and exclusion criteria and a well-controlled intervention. It was assumed that both techniques could obtain the similar postoperative effects. TRIAL REGISTRATION: This study protocol was registered in Research Registry (researchregistry5878).

Anatomical conditions and patient-specific locked navigation templates for transverse sacroiliac screw placement: a retrospective study.

OBJECTIVE: To analyse the anatomical conditions of transverse sacroiliac screw (TSS) about the S1 and S2 segments in order to develop and validate a locked navigational template for TSS placement. METHODS: A total of 22 patients with sacral fractures were involved in this study from May 2018 to February 2019. Patients were divided into two groups according to the surgery procedure: locked template group and conventional group. The CT data of 90 normal sacra were analysed. The long axis, short axis and lengths of TSS, cancellous corridors were measured through 3D modelling. A patient-specific locked navigation template based on simulated screws was designed and 3D printed and then used to assist in TSS placement. The operative time and radiation times were recorded. The Matta criteria and grading score were evaluated. The entry point deviation of the actual screw placement relative to the simulated screw placement was measured, and whether the whole screw was in the cancellous corridor was ob`served. RESULTS: S1 screws with a diameter of 7.3 mm could be inserted into 69 pelvises, and S2 screws could be inserted in all pelvises. The S1 cancellous corridor had a long axis of 25.44 ± 3.32 mm in males and 22.91 ± 2.46 mm in females, a short axis of 14.21 ± 2.19 mm in males and 12.15 ± 3.22 mm in females, a corridor length of 153.07 ± 11.99 mm in males and 151.11 ± 8.73 mm in females, and a proportional position of the optimal entry point in the long axis of the cancellous corridor of 35.96 ± 10.31% in males and 33.28 ± 7.2% in females. There were significant differences in the corridor long axis and corridor short axis between sexes (p < 0.05), and there were no significant differences in corridor length and proportional position of the optimal entry point in the long axis of the cancellous corridor between sexes (p > 0.05). The S2 cancellous corridor had a long axis of 17.58 ± 2.36 mm in males and 16 ± 2.64 mm in females, a short axis of 14.21 ± 2.19 mm in males and 13.14 ± 2.2 mm in females, a corridor length of 129.95 ± 0.89 mm in males and 136.5 ± 7.96 mm in females, and a proportional position of the optimal entry point in the long axis of the cancellous corridor of 46.77 ± 9.02% in males and 42.25 ± 11.95% in females. There were significant differences in the long axis, short axis and corridor length (p < 0.05). There was no significant difference in the proportional position of the optimal entry point in the long axis of the cancellous corridor (p > 0.05). A total of 20 transversal sacroiliac screws were successfully implanted into 10 patients with the assistance of locked navigation templates, and a total of 24 transversal sacroiliac screws were successfully implanted into 12 patients under C-arm fluoroscopy. There was a significant difference in surgical time (88 ± 14.76 min vs 102.5 ± 17.12 min, p = 0.048), radiation times (11.5 ± 1.78 vs 54.83 ± 6.59, p < 0.05) and screw grading between two groups (nineteen screws in grade 0, one screw in grade 1 and 0 screws in grade 2 vs fourteen screws in grade 0, 8 screws in grade 1 and 2 screws in grade 2, p = 0.005). All screw entry point deviations were shorter than the short axis of the cancellous corridor, and all screws were located completely within the cancellous corridor. CONCLUSION: Approximately 76% of males and females can accommodate screws with diameters of 7.3 mm in S1, and all persons can accommodate the same screw in S2. From the standard lateral perspective of the sacrum, the optimal entry point of the transverse screw is in the first 1/3 of the cancellous corridor for S1 and the centre of the cancellous corridor for S2. The patient-specific locked navigation template assisted in TSS placement with less operative time, less intraoperative fluoroscopy and higher safety of screw placement compared with traditional surgery.

Percutaneous Pedicle Screw Placement Aided by a New Drill Guide Template Combined with Fluoroscopy: An Accuracy Study.

OBJECTIVE: To evaluate the accuracy of percutaneous pedicle screw (PPS) placement aided by a new drill guide template. METHODS: The patients were divided into guide template group and conventional perspective group. In the conventional perspective group, the screws were placed by hand under fluoroscopy. In the guide template group, the screw placement was aided by a new drill guide template, and the drill guide template is designed according to the patient's ideal pedicle screw, but not based on skin morphology. The accuracy was evaluated by comparing the following parameters between the two groups: pedicle breach level, inclination angle deviation between the left and right screws, sagittal angle deviation between the left and right screws, and position deviation of the left and right screw entry points. The consistency of the postoperative screw angle and the corresponding guide template inclination angle was compared in the guide template group. The operative time, blood loss, and radiation times were compared between the groups. RESULTS: A total of 146 patients (876 screws) were enrolled in our study including 79 (474 screws) in the guide template group and 67 (402 screws) in the conventional perspective group. The pedicle breach level in the guide template group (22/474) was significantly lower than that in the conventional perspective group (47/402) (P < 0.05). The position and direction deviations of the left and right screws in the guide template group (2.06 ± 1.02 mm, 1.23 ± 1.25 mm, 1.83° ± 1.49°) were significantly less than those in the conventional perspective group (5.33 ± 2.99 mm, 4.32 ± 3.25 mm, 2.87° ± 1.56°). The operation time, blood loss, and radiation times were significantly lower in the guide template group (80.49 ± 9.14 min, 50.42 ± 8.9 mL, 11.02 ± 2.44) than those in the conventional perspective group (108.1 ± 21.18 min, 71.7 ± 17.09 mL, 23.53 ± 4.54). There were no significant differences between the postoperative screw angle and the corresponding guide template angle in the guide template group. CONCLUSION: PPS placement aided by a new drill guide template yielded higher screw accuracy and less operative time, blood loss, and radiation exposure than traditional screw placement.

Combined 3D Printed Template to Guide Iliosacral Screw Insertion for Sacral Fracture and Dislocation: A Retrospective Analysis.

OBJECTIVE: To evaluate the accuracy and safety of a combined 3D printed guide template (combined template) to assist iliosacral (IS) screw placement for sacral fracture and dislocation. METHODS: A total of 37 patients, 24 men and 13 women, age from 22 to 68 years old, diagnosed with a sacral fracture and dislocation were involved in this study for retrospective analysis from January 2016 to February 2018. There were 19 patients in the template group (42 screws) and 18 patients in the conventional group (31 screws). In the combined template group, IS screw placement was assisted by a combined 3D printed template; in the conventional group, the IS screws were placed freehand under fluoroscopy. The accuracy of the IS screw placement was evaluated by comparing the screw angle and the location of the screw entry point between the actual and the simulated screw in the combined template group. The safety of the IS screw placement was evaluated by comparing the quality of the reduction, the grading of the screws, the operation time, and radiation exposure times between groups. RESULTS: A total of 73 pedicle screws were placed in 37 patients: 42 screws (30 S1, 12 S2) in the combined template group and 31 screws (23 S1, 8 S2) in the conventional group. In the conventional group, 1 patient developed symptoms of L5 nerve stimulation. In the combined template group, the average operative time of each screw was 25.01 ± 2.90 min, with average radiation exposure times of 12.05 ± 4.00. In the conventional group, the average operative time of each screw was 46.24 ± 9.59 min, with an average radiation exposure time of 56.10 ± 6.75. There were significant differences in operation and radiation exposure times between groups. The rate of screw perforation was lower in the combined template group (2 of 42 screws, 0 at grade III and 2 at grade II) than in the conventional group (5 of 38 screws, 2 at grade III and 3 at grade III). In the combined template group, the mean distance between the entry points of the actual and simulated screws was 1.4 ± 0.9 mm, with a mean angle of deviation of 2.1° ± 1.6°. All patients were followed up once every 3 months and were followed for 3 to 12 months. CONCLUSION: Using the combined template to assist with the insertion of IS screws delivered good accuracy, less fluoroscopy and shorter operation time, and avoided neurovascular injury as a result of screw malposition.

[Effectiveness analysis of three-dimensional printing assisted surgery for unstable pelvic fracture].

OBJECTIVE: To evaluate the effectiveness of three-dimensional (3D) printing assisted internal fixation for unstable pelvic fractures. METHODS: The clinical data of 28 patients with unstable pelvic fractures admitted between March 2015 and December 2017 were retrospectively analyzed. The patients were divided into two groups according to different surgical methods. Eighteen cases in the control group were treated with traditional anterior and posterior open reduction and internal fixation with plate; 10 cases in the observation group were treated with 3D printing technology to make pelvic models and assist in shaping the subcutaneous steel plates of the anterior ring. Sacroiliac screw navigation template was designed and printed to assist posterior ring sacroiliac screw fixation. There was no significant difference between the two groups in gender composition, age, cause of injury, fracture type, and time interval from injury to surgery ( P>0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy times, incision length, waiting time for weight-bearing exercise, and fracture healing time were recorded and compared between the two groups. Majeed score was used to evaluate the function at last follow-up. At immediate after operation, the reduction was evaluated according to Matta imaging scoring criteria, and the success of sacroiliac joint screw implantation in the observation group was evaluated. The deviation of screw entry point and direction between postoperative screws and preoperative simulated screws were compared in the observation group. RESULTS: All the operation was successfully completed, and all patients were followed up 6-18 months (mean, 14.4 months). In the control group, 1 case had wound infection and 2 cases had deep vein thrombosis. No serious complication such as important blood vessels, and nerve injury and pulmonary embolism occurred in other patients in the two groups. No screw pulling out or steel plate breaking occurred. The operation time, intraoperative blood loss, fluoroscopy times, incision length, and waiting time for weight-bearing exercise of the control group were significantly more than those of the observation group ( P<0.05); there was no significant difference in fracture healing time between the two groups ( t=0.12, P=0.90). There was no significant difference in reduction quality between the two groups at immediate after operation ( Z=-1.05, P=0.30); Majeed score of the observation group was significantly better than that of the control group at last follow-up ( Z=-2.42, P=0.02). The success rate of sacroiliac joint screw implantation in the observation group reached category Ⅰ. In the observation group, the deviation angle of the direction of the screw path between the postoperative screw and the preoperative simulated screw implant was (0.09±0.22)°, and the deviation values of the entry points on the X, Y, and Z axes were (0.13±0.63), (0.14±0.58), (0.15±0.53) mm, respectively. There was no significant difference when compared with those before the operation (all values were 0) ( P>0.05). CONCLUSION: Computer design combined with 3D printing technology to make personalized pelvic model and navigation template applied to unstable pelvic fractures, is helpful to accurately place sacroiliac screw, reduce the operation time, intraoperative blood loss, and the fluoroscopy times, has good waiting time for weight-bearing exercise and function, and it is an optional surgical treatment for unstable fractures.

[Accuracy analysis and clinical application of the progressive navigation template system to assist atlas-axial pedicle screw placement].

Objective: To investigate the accuracy of progressive three-dimensional navigation template system (abbreviated as progressive template) to assist atlas-axial pedicle screw placement. Methods: The clinical data of 33 patients with atlas-axial posterior internal fixation surgery between May 2015 and May 2017 were retrospectively analyzed. According to the different methods of auxiliary screw placement, the patients were divided into trial group (19 cases, screw placement assisted by progressive template) and control group (14 cases, screw placement assisted by single navigation template system, abbreviated as initial navigation template). There was no significant difference in gender, age, cause of injury, damage segments, damage types, and preoperative Frankel classification between the two groups ( P>0.05). The operation time and intraoperative blood loss of the two groups were compared. The safety of screw placement was evaluated on postoperative CT by using the method from Kawaguchi et al, the deviation of screw insertion point were calculated, the angular deviation of the nailing on coordinate systems XOZ, XOY, YOZ were calculated according to Peng's method. Results: All patients completed the operation successfully; the operation time and intraoperative blood loss in the trial group were significantly less than those in the control group ( t=-2.360, P=0.022; t=-3.006, P=0.004). All patients were followed up 12-40 months (mean, 25.3 months). There was no significant vascular injury or nerve injury aggravation. Postoperative immediate X-ray film and CT showed the dislocation was corrected. Postoperative immediate CT showed that all 76 screws were of grade 0 in the trial group, and the safety of screw placement was 100%; 51 screws were of grade 0, 3 of gradeⅠ, and 2 of gradeⅡ in the control group, and the safety of screw placement was 91.1%; there was significant difference in safety of screw placement between the two groups ( χ2=7.050, P=0.030). The screw insertion point deviation and angular deviation of the nailing on XOY and YOZ planes in the trial group were significantly less than those in the control group ( P<0.05). There was no significant difference in angular deviation of the nailing on XOZ between the two groups ( t=1.060, P=0.290). Conclusion: Compared with the initial navigation template, the progressive navigation template assisting atlas-axial pedicle screw placement to treat atlas-axial fracture with dislocation, can reduce operation time and intraoperative blood loss, improve the safety of screw placement, and match the preoperative design more accurately.

The establishment and biological assessment of a whole tissue-engineered intervertebral disc with PBST fibers and a chitosan hydrogel in vitro and in vivo.

Intervertebral disc (IVD) degeneration (IDD) is the main cause of low back pain in the clinic. In the advanced stage of IDD, both cell transplantation and gene therapy have obvious limitations. At this stage, tissue-engineered IVDs (TE-IVDs) provide new hope for the treatment of this disease. We aimed to construct a TE-IVD with a relatively complete structure. The inner annulus fibrosus (AF) was constructed using poly (butylene succinate-co-terephthalate) copolyester (PBST) electrospun fibers, and the outer AF consisted of solid PBST. The nucleus pulposus (NP) scaffold was constructed using a chitosan hydrogel, as reported in our previous research. The three components were assembled in vitro, and the mechanical properties were analyzed. AF and NP cells were implanted on the corresponding scaffolds. Then, the cell-seeded scaffolds were implanted subcutaneously in nude mice and cultured for 4 weeks; then they were removed and implanted into New Zealand white rabbits. After 4 weeks, their properties were analyzed. The PBST outer AF provided mechanical support for the whole TE-IVD. The electrospun film and chitosan hydrogel simulated the natural structure of the IVD well. Its mechanical property could meet the requirement of the normal IVD. Four weeks later, X-ray and MR imaging examination results suggested that the height of the intervertebral space was retained. The cells on the TE-IVD expressed extracellular matrix, which indicated that the cells maintained their biological function. Therefore, we conclude that the whole TE-IVD has biological and biomechanical properties to some extent, which is a promising candidate for IVD replacement therapies. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2305-2316, 2019.

Novel nano-microspheres containing chitosan, hyaluronic acid, and chondroitin sulfate deliver growth and differentiation factor-5 plasmid for osteoarthritis gene therapy.

OBJECTIVE: To construct a novel non-viral vector loaded with growth and differentiation factor-5 (GDF-5) plasmid using chitosan, hyaluronic acid, and chondroitin sulfate for osteoarthritis (OA) gene therapy. METHODS: Nano-microspheres (NMPs) were prepared by mixing chitosan, hyaluronic acid, and chondroitin sulfate. GDF-5 plasmid was encapsulated in the NMPs through electrostatic adsorption. The basic characteristics of the NMPs were observed, and then they were co-cultured with chondrocytes to observe their effects on extracellular matrix (ECM) protein expression. Finally, NMPs loaded with GDF-5 were injected into the articular cavities of rabbits to observe their therapeutic effects on OA in vivo. RESULTS: NMPs exhibited good physicochemical properties and low cytotoxicity. Their average diameter was (0.61±0.20) µm, and encapsulation efficiency was (38.19±0.36)%. According to Cell Counting Kit-8 (CCK-8) assay, relative cell viability was 75%-99% when the total weight of NMPs was less than 560 µg. Transfection efficiency was (62.0±2.1)% in a liposome group, and (60.0±1.8)% in the NMP group. There was no significant difference between the two groups (P>0.05). Immunohistochemical staining results suggested that NMPs can successfully transfect chondrocytes and stimulate ECM protein expression in vitro. Compared with the control groups, the NMP group significantly promoted the expression of chondrocyte ECM in vivo (P<0.05), as shown by analysis of the biochemical composition of chondrocyte ECM. When NMPs were injected into OA model rabbits, the expression of ECM proteins in chondrocytes was significantly promoted and the progression of OA was slowed down. CONCLUSIONS: Based on these data, we think that these NMPs with excellent physicochemical and biological properties could be promising non-viral vectors for OA gene therapy.

Regenerative Intervertebral Disc Endplate Based on Biomimetic Three-dimensional Scaffolds.

STUDY DESIGN: Fabrication and characterization of a regenerative intervertebral disc (IVD) cartilaginous endplate (CEP) based on tissue culturing on biomimetic scaffolds. OBJECTIVE: To fabricate a regenerative CEP to support nutrients and metabolites exchange between IVD and the milieu interior. SUMMARY OF BACKGROUND DATA: CEP is the only pathway for most cells inside IVD to obtain nutrients and to eliminate metabolites. However, CEP usually fails at the same time when IVD degenerates. Therefore, reconstruction of CEP becomes an inevitable part of IVD regeneration. In this work, a novel regenerative CEP is fabricated to support nutrients and metabolites exchange of IVD. METHODS: Three-dimensional scaffolds were fabricated by crosslinking of hyaluronic acid, chondroitin sulfate, and type II collagen. Then chondrocytes were cultured on the scaffolds. The obtained tissue was then investigated by scanning electron microscope, mechanical tests, and immunohistochemistry tests. In the end, glucose and lactic acid diffusion was carried out to test its nutrients and metabolites exchanging property. RESULTS: Scanning electron microscopy investigations show that the 3-dimensional scaffold has microporous structure. After cell culturing, the inner structure of the obtained product becomes compact. Mechanical tests show that the obtained tissue has strong mechanical property. Immunohistochemistry tests show that the chemical compositions of the fabricated regenerative CEP are the same as its natural counterpart. Moreover, glucose and lactic acid diffuse through the regenerative CEP successfully. CONCLUSION: The fabricated regenerative CEP shows features similar to its natural counterpart. As the most important function, nutrients and metabolites exchange is verified on it as well. This regenerative CEP may play an important role in overall fabrication of regenerative IVD in near future. LEVEL OF EVIDENCE: N/A.