Comparison of Computer-Assisted Navigation and 3D Printed Patient-Specific Template for the Iliosacral Screw Placement.

BACKGROUND: Iliosacral screw insertion by computer-assisted navigation gradually became the main technique in some hospitals, but the expensive price limited the extensive application. But other techniques such as 3D printed template was used to place iliosacral screw as novel method. This study was to compare the efficiency of percutaneous iliosacral screw placement by using patient-specific template and computer-assisted navigation. METHODS: Total of 58 patients from September 2017 to September 2021 with sacral injury were treated operatively with percutaneous screw technique, which was selected for this retrospective analysis and divided into two groups (template and computer-assisted navigation). There were 31 patients in template group and 27 patients in computer-assisted navigation group. The surgical details (operation time, blood loss, number of screw placements, and number of fluoroscopies), complications, radiographic and clinical results were recorded. The quality of reduction was assessed by the Matta scoring system. T-test and rank-sum test was used in this study. RESULTS: Operation time in template group was less (33.97 ± 16.61 < 60.31 ± 11.46 min, p < 0.01), but the preoperative preparation time was more (6.35 ± 1.60 > 5.41 ± 1.58, p < 0.05). The quality of reduction in both groups was no difference (p = 0.352). A patient was complicated with gluteal vessel injury in operation in navigation group, which was treated with ligation, but the same injury was not observed in template group. The related surgical data of patient with gluteal injury was ignored in statistical analysis. CONCLUSION: Both of the two techniques could improve surgical efficiency, the operation time in template was less than computer-assisted navigation group, but the preoperative preparation time was more.

Bulk RNA-seq and scRNA-seq reveal SLC7A11, a key regulatory molecule of ferroptosis, is a prognostic-related biomarker and highly related to the immune system in lung adenocarcinoma.

Lung adenocarcinoma (LUAD) is the most common pathological subtype of lung cancer. Ferroptosis is an iron-dependent, non-apoptotic cell death mode, highly correlated with the tumorigenesis and progression of multiple cancers. Solute carrier family 7 member 11 (SLC7A11) maintains the anti-porter activity of cysteine and glutamate to regulate ferroptosis. We collected bulk RNA-seq and scRNA-seq from The Cancer Genome Altas and Gene Expression Omnibus databases. Then, we extracted the expression level of SLC7A11 to perform the differential expression analysis between normal tissues and LUAD tissues. Then, we applied survival, univariate, and multivariate Cox regression analyses to investigate the predictive value of SLC7A11 in LUAD. Gene set enrichment analysis was used to explore the underlying molecular mechanisms of SLC7A11 in LUAD. Finally, we analyzed the relationship of SLC7A11 to the immune status and the curative effect of immunotherapy. The expression level of SLC7A11 in LUAD tissues was markedly increased. The survival analysis, univariate and multivariate Cox regression analysis showed that SLC7A11 was a negative factor for the prognosis of LUAD patients. Gene set enrichment analysis revealed that several immune-related pathways were enriched in the low-level group. The lower SLC7A11 level has a better therapeutic effect of immunotherapy and less probability of immune escape and dysfunction. SLC7A11 was a prognostic-related biomarker and closely correlated with the immune status and therapeutic effect of immunotherapy in LUAD, which could be an effective biomarker for evaluating the prognosis and the therapeutic efficacy of immunotherapy.

Both-column Acetabular Fractures with Posterior Wall Involved can be Managed through Single Anterior Approach by Evaluation of Computer-assisted Virtual Surgery Technique.

OBJECTIVE: Posterior wall (PW) fractures were sometimes associated in both-column acetabular fractures. How to evaluate pre-operatively the necessity for the performance of the posterior approach was an issue to be solved. In order to solve this issue, the computer-assisted virtual surgery technique was used to evaluate if the involved PW in both-column acetabular fractures (BACF) should be managed through posterior approach and verify the feasibility of this method. METHODS: Data of a consecutive cohort of 72 patients with both-acetabular fractures from January 2012 to January 2020 was collected for retrospective study, of which 44 patients had concomitant acetabular PW fractures, and patients without PW fractures were labeled as the BCAF group. Computer-assisted virtual surgery technique was performed pre-operatively to evaluate the necessity for performance of posterior approach in 44 patients, and posterior approach was required if more than 3 mm of displacement was still present in the reduced 3D model. The 23 patients without treatment through posterior approach were labeled as the BCAF-PW- group, and the 21 patients with treatment through posterior approach were labeled as the BCAF-PW+ group. Operation-related and post-operative parameters were recorded. The quality of reduction and functional outcomes were assessed by the Matta scoring system and modified Merle d'Aubigné and Postel scoring system. The measurement data were analyzed using the t-test of independent samples and rank-sum test of ranked data between every two groups. Also, the one-way analysis of variance (ANOVA) was used to analyze data between the three groups. RESULTS: Comparing operation-related and post-operative parameters in the three groups, some PW fractures in both-column acetabular fractures could be ignored, and which could be evaluated pre-operatively for necessity of an additional posterior approach. Operative time (271.2 ± 32.8 mins) and intra-operative blood loss (1176.7 ± 211.1 mL) were significantly higher in the BCAF-PW+ group. The excellent/good of reduction (25/28 of the BCAF group, 21/23 of the BCAF-PW- group, 19/21 of the BCAF-PW+ group) and functional outcomes (24/28 of the BCAF group, 18/23 of the BCAF-PW- group, 18/21 of the BCAF-PW+ group) of three groups were similar. The incidence of complications, such as deep vein thrombosis (4/28 of the BCAF group >3/23 of the BCAF-PW- group >1/21 of the BCAF-PW+ group) and injury of lateral femoral cutaneous nerve (3/23 of the BCAF-PW- group >2/28 of the BCAF group >0/21 of the BCAF-PW+ group), was no significant difference. CONCLUSION: The partial both-column acetabular fractures with PW involvement could be managed through a single anterior approach without another posterior approach by evaluation of computer-assisted virtual surgery technique.

Biomechanical study of different fixation constructs for anterior column and posterior hemi-transverse acetabular fractures: a finite element analysis.

BACKGROUND: To compare the biomechanical properties and stability, using a finite element model, of four fixation constructs used for the treatment of anterior column and posterior hemi-transverse (ACPHT) acetabular fractures under two physiological loading conditions (standing and sitting). METHODS: A finite element model simulating ACPHT acetabular fractures was created for four different scenarios: a suprapectineal plate combined with posterior column and infra-acetabular screws (SP-PS-IS); an infrapectineal plate combined with posterior column and infra-acetabular screws (IP-PS-IS); a special infrapectineal quadrilateral surface buttress plate (IQP); and a suprapectineal plate combined with a posterior column plate (SP-PP). Three-dimensional finite element stress analysis was performed on these models with a load of 700 N in standing and sitting positions. Biomechanical stress distributions and fracture displacements were analysed and compared between these fixation techniques. RESULTS: In models simulating the standing position, high displacements and stress distributions were observed at the infra-acetabulum regions. The degree of these fracture displacements was low in the IQP (0.078 mm), as compared to either the IP-PS-IS (0.079 mm) or the SP & PP (0.413 mm) fixation constructs. However, the IP-PS-IS fixation construct had the highest effective stiffness. In models simulating the sitting position, high fracture displacements and stress distributions were observed at the regions of the anterior and posterior columns. The degree of these fracture displacements was low in the SP-PS-IS (0.101 mm), as compared to the IP-PS-IS (0.109 mm) and the SP-PP (0.196 mm) fixation constructs. CONCLUSION: In both standing and sitting positions, the stability and stiffness index were comparable between the IQP, SP-PS-IS, and IP-PS-IS. These 3 fixation constructs had smaller fracture displacements than the SP-PP construct. The stress concentrations at the regions of quadrilateral surface and infra-acetabulum suggest that the buttressing fixation of quadrilateral plate was required for ACPHT fractures.

Finite element analysis of posterior acetabular column plate and posterior acetabular wall prostheses in treating posterior acetabular fractures.

BACKGROUND: The purpose of this study was to investigate the mechanical stability of the posterior acetabular column plate and different posterior acetabular wall prostheses used in treating posterior acetabular fractures with or without comminution. METHODS: The unilateral normal ilium was reconstructed, and a model of posterior acetabular wall fracture was established on this basis. The fracture fragment accounted for approximately 40% of the posterior acetabular wall. The posterior acetabular column plate and different posterior acetabular wall prostheses were also designed. Using static and dynamic analysis methods, we observed and compared the changes in the stress and displacement values of different models at different hip joint flexion angles under external forces. RESULTS: At different hip flexion angles, the stress of each model mainly fluctuated between 37.98 MPa and 1129.00 MPa, and the displacement mainly fluctuated between 0.076 and 6.955 mm. In the dynamic analysis, the nodal stress‒time curves of the models were nonlinear, and the stress changed sharply during the action time. Most of the nodal displacement‒time curves of the models were relatively smooth, with no dramatic changes in displacement during the action time; additionally, most of the curves were relatively consistent in shape. CONCLUSIONS: For simple posterior acetabular wall fractures, we recommend using a posterior acetabular column plate. In the case of comminuted posterior acetabular fractures, we recommend the use of a nonflanked posterior acetabular prosthesis or a biflanked posterior acetabular prosthesis. Regarding the method of acetabular prosthesis design, we propose the concept of "Break up to Make up" as a guide.

Both-Column Acetabular Fractures: Should Pelvic Ring Reduction or Acetabulum be Performed First?

OBJECTIVE: Both-column acetabular fracture is a type that accumulates both the pelvis and acetabulum with complex fracture line alignment and has variant fracture fragments. The selection of different reduction landmarks and sequences produces different qualities of reduction. This study aims to compare the operation-related items, quality of reduction, and hip functional outcome by using different reduction landmarks and sequences for management of both-column acetabular fractures (BCAF). METHODS: A consecutive cohort of 42 patients from January 2013 to January 2019 with BCAF were treated operatively with different reduction landmarks and sequences: pelvic ring fractures reduction first (PRFRF group) and acetabular fractures reduction first (AFRF group). Preoperative computer visual surgical procedures were applied. There were 22 patients in PRFRF group and 20 patients in AFRF group. The surgical details, complications, radiographic and clinical results were recorded. The quality of reduction was assessed by the Matta scoring system. The functional outcome was evaluated by the modified Merle d'Aubigné and Postel scoring system. The measurement data were analyzed using the t-test of independent samples and rank-sum test of ranked data. RESULTS: The real reduction sequence in both groups was almost identical to the preoperative surgical procedures. The excellent/good quality of reduction in PRFRF group (21/22) was better than AFRF group (17/20). Operative time (152.3 ± 16.3 mins) and intra-operative blood loss (639.5 ± 109.9ml) were significantly reduced in PRFRF group (p < 0.05). The incidence of deep vein thrombosis in PRFRF group (2/22) was less than AFRF group (4/20), but without statistical signification. CONCLUSION: Selection of an appropriate reduction landmark and sequence could result in better quality of reduction, operative time, and decreased blood loss during treatment of BCAF.

The novel infra-pectineal buttress plates used for internal fixation of elderly quadrilateral surface involved acetabular fractures.

OBJECTIVES: In geriatric acetabular fractures, the quadrilateral surface (QLS) was frequently involved in acetabular fracture patterns and accompanied by medial displacement. It was important to buttress the medial displaced QLS and reconstruct the congruity of the affected acetabulum. To evaluate the clinical effectiveness of the novel infra-pectineal quadrilateral surface buttress plates for the treatment of geriatric acetabular fractures. METHODS: Twenty-three geriatric patients who were treated for acetabular fractures involving QLS with the novel infra-pectineal buttress plates (NIBP) through a single supra-ilioinguinal approach between January 2015 and June 2019 were retrospectively analyzed; all patients received at least 1 year's follow-up. All patients were aged ≥60 years old and including 18 males and five females. Radiologic and clinical outcomes of patients involved in the study were collated and analyzed according to the Matta scoring system and the Merle D'Aubigné-Postel scoring system. The functional recovery scoring was compared using q-test. RESULTS: All 23 consecutive patients had relatively satisfactory clinical treatment effectiveness. Average ages, length of incision, operation time, and intraoperative blood loss were 69.8 ± 6.1 years, 12.1 ± 2.6 cm, 166.5 ± 43.5 min, and 500 (500,700) ml, respectively. According to the Matta scoring system, 14 cases of reduction were graded as excellent, five as good, and four as fair. At the last follow-up, the clinical outcome evaluation was excellent in 13 cases, good in seven cases, and poor in three cases with the use of the Merle D'Aubigné-Postel scoring system. The difference of modified Merle D'Aubigne-Postel score at 3 months, 6 months and last follow up was statistically significant (F = 21.56, p < 0.05). Postoperative lateral femoral cutaneous nerve injury occurred in three patients and heterotopic ossification occurred in one patient. CONCLUSIONS: For the treatment of geriatric acetabular fractures, the NIBP could provide stable and effective fixation to the QLS involved acetabular fractures, and related satisfactory clinical results with few complications were noted.

Finite element analysis of the Union Plate in treating elderly acetabular fracture patients.

BACKGROUND: Elderly acetabular fractures are one of the more difficult types of fractures to resolve. For patients at this age, the more common type of fracture is comminuted. How to better fix this type of fracture has always been an issue of concern. This study was performed to observe the mechanical properties of different internal fixation methods used in treating elderly acetabular fracture patients. METHODS: A model of a comminuted acetabular fracture in osteoporosis was established, consisting of an anterior column-posterior hemitransverse fracture with disruption of the quadrilateral surface. Fixation of the acetabular fracture model using a reconstruction plate and Union Plates was simulated. For the different internal fixation methods, static and transient modal analyses were performed under different loads, with an action time of 0.21 s and an analysis time of 0.7 s. The stress of the model was observed in the static analysis, and the displacement of the nodes and the entire model in the U1 direction was observed in the transient modal analysis. RESULTS: In the static analysis, the stress of the osteoporosis model, the suprapectineal pelvic reconstruction plate model, the infrapectineal quadrilateral surface buttress plate model, and the suprapectineal quadrilateral surface buttress plate model were 42.62 MPa, 37.49 MPa, 44.39 MPa, and 46.15 MPa, respectively. The stress was mainly distributed near the suprapubic branch. The corresponding displacement in the U1 direction was 0.1500 mm, 0.1020 mm, 0.0836 mm, and 0.0990 mm, respectively. In the transient modal analysis, there was a significant difference in displacement between the different models (P < 0.05). When different loads were applied with the same fixation method, there was no significant difference in model displacement (P > 0.05). CONCLUSION: Static and transient modal analyses show that the infrapectineal quadrilateral surface buttress plate or the suprapectineal quadrilateral surface buttress plate has an advantage in maintaining the stability of fracture fragments when fixing comminuted acetabular fractures in elderly individuals. The infrapectineal quadrilateral surface buttress plate also presents better biomechanical results.

Controlled delivery of bone morphogenic protein-2-related peptide from mineralised extracellular matrix-based scaffold induces bone regeneration.

Ideal bone tissue engineering scaffolds composed of extracellular matrix (ECM) require excellent osteoconductive ability to imitate the bone environment. We developed a mineralised tissue-derived ECM-modified true bone ceramic (TBC) scaffold for the delivery of aspartic acid-modified bone morphogenic protein-2 (BMP-2) peptide (P28) and assessed its osteogenic capacity. Decellularized ECM from porcine small intestinal submucosa (SIS) was coated onto the surface of TBC, followed by mineralisation modification (mSIS/TBC). P28 was subsequently immobilised onto the scaffolds in the absence of a crosslinker. The alkaline phosphatase activity and other osteogenic differentiation marker results showed that osteogenesis of the P28/mSIS/TBC scaffolds was significantly greater than that of the TBC and mSIS/TBC groups. In addition, to examine the osteoconductive capability of this system in vivo, we established a rat calvarial bone defect model and evaluated the new bone area and new blood vessel density. Histological observation showed that P28/mSIS/TBC exhibited favourable bone regeneration efficacy. This study proposes the use of mSIS/TBC loaded with P28 as a promising osteogenic scaffold for bone tissue engineering applications.

Internal fixation of anterior acetabular fractures with a limited pararectus approach and the anatomical plates: preliminary results.

BACKGROUND: The surgical treatment of acetabular fracture has adverse outcomes and high risk, and minimally invasive method is a good way to reduce complications and improve hip joint function. This study is to investigate the treatment of certain acetabular fractures primarily involving the anterior column and quadrilateral plate using a limited pararectus approach and the anatomical plates. METHODS: A consecutive cohort of 17 patients with anterior displaced acetabular fractures were managed operatively with a limited approach and the anatomical plates. Ten patients had anterior column fractures, 1 patient had anterior wall fracture, 4 patients had transverse fractures and 2 patients had anterior column with posterior hemi-transverse fractures. The inferior half of the pararectus approach was adopted to open the medial window and to access the anterior column and the quadrilateral plate. The anatomical plates were used for internal fixation. Residual displacements were assessed on the postoperative CT scans using a standardized digital method. The surgical details, hip functional outcomes, and complications were noted. RESULTS: All of the patients were operated using the limited pararectus approach and the anatomical plates successfully. The mean operative time and blood loss were 90.9 min and 334.1 ml, respectively. The average postoperative residual gap and step displacement on CT were 2.9 mm and 0.7 mm, respectively. The radiological outcome was estimated according to the Matta score, ten of the cases were graded anatomical, six were graded imperfect, and one was graded poor. Follow up averaged 15 months. Functional outcomes were excellent for nine, good for six, and fair for two. It was noted that one case of peritoneal injury was repaired intraoperatively. CONCLUSIONS: The limited pararectus approach with the advantages of less trauma, direct exposure to the anterior column and quadrilateral plate. The anatomical plates can fit with the surface of the acetabulum, which saves the time of remodeling plates during operation and facilitate fracture reduction. The combination approach can be a good choice for limited surgery of displaced anterior acetabular fractures especially involving the quadrilateral plate.

Treatment of anterior column posterior hemitransverse fracture with supra-ilioinguinal approach.

OBJECTIVE: To report the feasibility and effect of the supra-ilioinguinal approach for treatment of anterior posterior hemitransverse fracture of the acetabulum. METHODS: Nineteen consecutive patients who underwent treatment for an anterior column posterior hemitransverse fracture of the acetabulum from January 2013 to June 2018 were retrospectively analyzed. All patients underwent treatment by the single supra-ilioinguinal approach with at least 1 year of follow-up. RESULTS: The mean time to surgery, operative time, incision length, and blood loss were 10.2 ± 3.8 days, 157 ± 125 minutes, 10.2 ± 0.6 cm, and 876 ± 234 mL, respectively. According to the Matta scoring system, the reduction quality was excellent in 13 patients, good in 6, and poor in 0. According to the Merle d'Aubigné scoring system, the outcome at the last follow-up was excellent in 12 patients, good in 5, fair in 1, and poor in 1. Postoperative complications occurred in three patients (deep vein thrombosis in one, lateral femoral cutaneous nerve injury in one, and both complications in one). CONCLUSIONS: Use of the supra-ilioinguinal approach for treatment of anterior column posterior hemitransverse fracture of the acetabulum produced excellent clinical results because of the direct visualization of the anterior column and quadrilateral plate.

Creation of Bony Microenvironment with Extracellular Matrix Doped-Bioactive Ceramics to Enhance Osteoblast Behavior and Delivery of Aspartic Acid-Modified BMP-2 Peptides.

INTRODUCTION: Decellularized matrix from porcine small intestinal submucosa (SIS) endows scaffolds with an ECM-like surface, which enhances stem cell self-renewal, proliferation, and differentiation. Mesoporous bioactive glass (MBG) is extensively recognized as an excellent bio-ceramic for fabricating bone grafts. MATERIALS AND METHODS: In the current study, SIS was doped on an MBG scaffold (MBG/SIS) using polyurethane foam templating and polydopamine chemistry method. To mimic the bony environment of a natural bone matrix, an ECM-inspired delivery system was constructed by coupling the BMP2-related peptide P28 to a heparinized MBG/SIS scaffold (MBG/SIS-H-P28). The release of P28 from MBG/SIS-H-P28 and its effects on the proliferation, viability, and osteogenic differentiation of bone marrow stromal stem cells were investigated in vitro and in vivo. RESULTS: Our research indicated that the novel tissue-derived ECM scaffold MBG/SIS has a hierarchical and interconnected porous architecture, and superior biomechanical properties. MBG/SIS-H-P28 released P28 in a controlled manner, with the long-term release time of 40 d. The results of in vitro experiments showed improvements in cell proliferation, cell viability, alkaline phosphatase activity, and mRNA expression levels of osteogenesis-related genes (Runx-2, OCN, OPN, and ALP) compared to those of MBG/SIS or MBG/SIS-P28 and MBG/SIS-H-P28. The in vivo results demonstrated that MBG/SIS-H-P28 scaffolds evidently increased bone formation in rat calvarial critical-sized defect compared to that in controls. CONCLUSION: MBG/SIS-H-P28 scaffolds show potential as ideal platforms for delivery of P28 and for providing a bony environment for bone regeneration.

Biomechanical Comparison of Different Fixation Techniques for Typical Acetabular Fractures in the Elderly: The Role of Special Quadrilateral Surface Buttress Plates.

BACKGROUND: Anterior column-posterior hemitransverse fractures are prevalent in the elderly and are often associated with quadrilateral surface (QLS) comminution. Several special QLS buttress plates have been introduced, but evidence of their comparability with traditional fixation devices is lacking. This biomechanical study aimed to compare special QLS buttress plates with traditional fixation devices. METHODS: Anterior column-posterior hemitransverse fractures with an isolated QLS fragment were created on 24 composite hemipelves and were allocated to 4 fixation groups: (1) infrapectineal QLS buttress plate, (2) suprapectineal QLS buttress plate, (3) suprapectineal reconstruction plate with 3 periarticular long screws, and (4) infrapectineal reconstruction plate with 3 periarticular long screws. Specimens were loaded to simulate partial weight-bearing (35 to 350 N) or full weight-bearing (75 to 750 N). A testing machine was synchronized with a 3-dimensional video tracking system to optically track displacement at the points of interest and to calculate construct stiffness. The fixation systems were compared using the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The experimental results of the partial and full weight-bearing simulations were surprisingly similar. During 40 loading cycles, the maximum displacement on the 6 predetermined points did not exceed 1.1 mm. Multiple-group comparisons of relative displacements of each predetermined measurement point did not differ significantly (p > 0.05). The suprapectineal reconstruction plate with 3 periarticular long screws demonstrated the greatest construct stiffness and significantly greater stiffness than the infrapectineal plate with long screws (p < 0.017). However, no significant difference (p > 0.017) in stiffness was identified between the infrapectineal QLS buttress plate and the suprapectineal reconstruction plate with long screws. CONCLUSIONS: The suprapectineal pelvic brim plate with 3 periarticular long screws remains the gold standard to treat anterior column-posterior hemitransverse fractures. The special infrapectineal QLS buttress plate provides stiffness and stability comparable with those of standard fixation. However, moving the pelvic brim plate from the suprapectineal border to the infrapectineal border is not recommended for anterior column-posterior hemitransverse fractures because it significantly decreases fixation stiffness. CLINICAL RELEVANCE: Special QLS buttress plates may be an alternative fixation method for anterior column-posterior hemitransverse acetabular fractures in the elderly, especially when a less invasive anterior intrapelvic approach is selected.

Supra-ilioinguinal versus modified Stoppa approach in the treatment of acetabular fractures: reduction quality and early clinical results of a retrospective study.

BACKGROUND: To compare the efficacy of the operative techniques, complications, reduction quality and hip functional recovery by using the supra-ilioinguinal approach and the modified Stoppa approach for the management of acetabular fractures. METHODS: A consecutive cohort of 60 patients from September 2014 to October 2017 with displaced acetabular fractures involving the quadrilateral plate were treated operatively with supra-ilioinguinal approach (group A) and modified Stoppa approach (group B), respectively. There were 36 patients in group A and 24 patients in group B. The surgical details, complications, radiographic and clinical results were recorded. The quality of reduction was assessed by measuring the residual step and gap displacement of postoperative CT with a standardized digital method. RESULTS: The complications, reduction quality (gaps and steps) and hip function recovery had no significant statistical difference in approaches. The mean operative time was shorter and the mean intraoperative haemorrhage was less in group A. There were statistical differences in the operative time (P = 0.025) and intraoperative haemorrhage (P = 0.003) between the supra-ilioinguinal approach and the modified Stoppa approach. CONCLUSION: Compared to the modified Stoppa approach, the supra-ilioinguinal approach provides a closer visualization to the quadrilateral plate, the operative time was shorter and the intraoperative haemorrhage was clearly less. It is at least equal to or could be a better choice to deal with complicated acetabular fractures especially involving the quadrilateral plate and the anterior one third of the iliac bone.

Minimally Invasive Screw Fixation of Unstable Pelvic Fractures Using the "Blunt End" Kirschner Wire Technique Assisted by 3D Printed External Template.

OBJECTIVE: This study aimed to determine the accuracy and safety of the "blunt end" Kirschner wire (KW) technique for the minimally invasive treatment of unstable pelvic fractures with the assistance of a 3D printed external template. METHODS: Clinical data of 28 patients with unstable pelvic fractures between January 2016 and January 2018 were retrospectively analyzed. There were 6 cases of B1, 10 of B2, 8 of C1, and 4 of C2 fractures, all of which received surgical treatment. The "blunt end" KW technique with a 3D template was adopted for the minimally invasive placement of the iliosacral (IS) or superior ramus screws. The number of intraoperative fluoroscopies, surgical time, and complications were recorded. Postoperative reduction was assessed using the Matta criteria, and the Majeed score system was used to evaluate postoperative functional recovery. RESULTS: The average number of fluoroscopies was 35 per patient, and the average surgical time was 85.2 min. A total of 19 S1 and 28 S2 IS screws were inserted. Eleven antegrade superior ramus screws and 4 retrograde screws were placed in 11 patients, and anterior subcutaneous internal fixation (INFIX) was used to fix the anterior pelvic ring in 17 patients. All patients were followed up for an average of 18 months. Postoperative reduction was evaluated by Matta's criteria: excellent in 16 cases, good in 9 cases, and fair in 3 cases. The Majeed score was used in the last follow-up to evaluate functional recovery: excellent in 13 cases, good in 10 cases, fair in 4 cases, and poor in 1 case. There were no cases of operative vascular injury. CONCLUSION: The "blunt end" KW technique with a 3D printed external template is a safe and effective method for the placement of IS and superior ramus screws in unstable pelvic fractures with minimized surgical duration and radiation exposure.

Early durotomy with duroplasty for severe adult spinal cord injury without radiographic abnormality: a novel concept and method of surgical decompression.

PURPOSE: Treatment options for adult spinal cord injury without radiographic abnormality (ASCIWORA) varied. Compression of ASCIWORA may more likely result from spinal cord lesions such as edema and hemorrhage or contusion. This study aimed to explore the clinical effect of early durotomy with duroplasty decompression in the treatment of severe ASCIWORA. METHODS: Data of 16 patients with ASCIWORA who underwent early ( < 72 h) posterior laminectomy followed by durotomy with duroplasty decompression from June 2015 to January 2017 were retrospectively analyzed. Patients' prognosis was analyzed by American Spinal Injury Association Impairment Scale (AIS) grades and scores. In 3 patients, intraspinal pressure (ISP) was continuously monitored for 1 week. RESULTS: Cervical magnetic resonance imaging (MRI) revealed spinal cord edema in 9 patients and suspected hemorrhage or contusion in 7 cases. Pathological manifestations of spinal cord injury found during the operation were consistent with preoperative MRI findings. Of the 16 cases, AIS grade was improved by 1 grade in 3 cases, 2 grades in 11 cases, and 3 grades in 1 case. The AIS scores at the last follow-up were significantly higher than preoperative scores. There was a high level of ISP after laminectomy, whereas ISP continued to decrease steadily after durotomy. CONCLUSIONS: Durotomy helps thoroughly decompress the spinal cord and improve cerebrospinal fluid circulation in severe ASCIWORA cases. Cervical MRI and pathological investigation of the spinal cord can be used to evaluate and predict the prognosis of ASCIWORA patients. ISP monitoring is an effective method for evaluating intramedullary pressure and decompression. These slides can be retrieved under Electronic Supplementary Material.

Application of computer-assisted virtual surgical procedures and three-dimensional printing of patient-specific pre-contoured plates in bicolumnar acetabular fracture fixation.

INTRODUCTION: With the rapid development of three-dimensional (3D) printing and computer technology, adopting computer-assisted virtual surgical procedures and 3D printing of patient-specific pre-contoured plates can greatly reduce surgical invasiveness and operative time and simplify the procedure. HYPOTHESIS: Use of computer-assisted virtual surgical procedures and 3D printing of patient-specific pre-contoured plates reduce the operative time and blood loss in bicolumnar acetabular fracture fixation. METHODS: A retrospective analysis was performed for 52 bicolumnar acetabular fracture cases treated surgically in our department from January 2013 to January 2017. According to the patients' willingness to accept 3D printing services, 52 patients were divided into groups A and B. In group A (28 patients), computer-assisted virtual surgical procedures and 3D printing of patient-specific pre-contoured plates were adopted. In group B (24 patients), the conventional method was adopted. Fracture type, operative blood loss, surgical time, complications, radiographic quality of reduction, and hip function were compared between groups. All patients were operated by the same surgeon. RESULTS: The real surgical procedure of all patients in group A was almost identical to the preoperative virtual operation. Operative time and intraoperative blood loss were significantly reduced in group A than in group B (p<0.05), while the postoperative fracture reduction quality and hip function obtained slightly higher levels of satisfaction in group A. CONCLUSIONS: Computer-assisted virtual surgical procedures, 3D printing technology and patient-specific pre-contoured plates can reduce the operative time and blood loss with less surgical invasiveness and ensure completely satisfactory clinical outcomes. However, promotion of this technology requires additional work. LEVEL OF EVIDENCE: III, therapeutic study.

Diverse preparation methods for small intestinal submucosa (SIS): Decellularization, components, and structure.

The native extracellular matrix (ECM) biomaterial derived from small intestinal submucosa (SIS) is widely applied in tissue engineering for tissue repair and regeneration. SIS ECM is obtained through physical and chemical methods to remove the intrinsic cells, which would otherwise cause adverse immune reactions when the SIS ECM is implanted into the host body. Several research teams have reported diverse SIS decellularization methods. However, there was no consensus on the criteria to be used for the decellularization methods for SIS and further research on the mechanism action of SIS is needed for comprehensive detection of the biological composition. In this present study, we used three reported methods to prepare SIS and compared their effects on decellularization and the remaining biological components, microstructure and cytocompatibility. SIS prepared by the three kinds of decellularization methods all achieved the recommended criteria, had good biocompatibility and retained most active components. Nevertheless, regardless of which decellularization method was used, the microstructure and bioactive components of the prepared SIS were damaged in varying degrees. We recommend that researchers need to select a decellularization method that would be appropriate to use according to their research purposes. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 689-697, 2019.

A novel patient-specific three-dimensional-printed external template to guide iliosacral screw insertion: a retrospective study.

BACKGROUND: Iliosacral screw fixation is a popular method for the management of posterior pelvic ring fractures or dislocations, providing adequate biomechanical stability. Our aim in this study was to describe the use of a new patient-specific external template to guide the insertion of iliosacral screws and to evaluate the efficacy and safety of this technique compared with the conventional fluoroscopy-guided technique. METHODS: This was a retrospective study of patients with incomplete or complete posterior pelvic ring disruptions who required iliosacral screw fixation. For analysis, patients were divided into two groups: the external template group (37 screws in 22 patients) and the conventional group (28 screws in 18 patients). The operative time per screw, radiation exposure time and the rate of screw perforation (accuracy) were compared between groups. In the external template group, the difference between the actual and planned iliosacral screw position was also compared. RESULTS: In the conventional group, the average operative time per screw was 39.7 ± 10.6 min, with an average radiation exposure dose of 1904.0 ± 844.5 cGy/cm2, with 4 cases of screw perforation. In the external template group, the average operative time per screw was 17.9 ± 4.7 min, with an average radiation exposure dose of 742.8 ± 230.6 cGy/cm2 and 1 case of screw perforation. In the template group, the mean deviation distance between the actual and planned screw position was 2.75 ± 1.0 mm at the tip, 1.83 ± 0.67 mm in the nerve root tunnel zone and 1.52 ± 0.48 mm at the entry point, with a mean deviation angle of 1.73 ± 0.80°. CONCLUSIONS: The external template provides an accurate and safe navigation tool for percutaneous iliosacral screw insertion that could decrease the operative time and radiation exposure.

Guided osteoporotic bone regeneration with composite scaffolds of mineralized ECM/heparin membrane loaded with BMP2-related peptide.

INTRODUCTION: At present, the treatment of osteoporotic defects poses a great challenge to clinicians, owing to the lower regeneration capacity of the osteoporotic bone as compared with the normal bone. The guided bone regeneration (GBR) technology provides a promising strategy to cure osteoporotic defects using bioactive membranes. The decellularized matrix from the small intestinal submucosa (SIS) has gained popularity for its natural microenvironment, which induces cell response. MATERIALS AND METHODS: In this study, we developed heparinized mineralized SIS loaded with bone morphogenetic protein 2 (BMP2)-related peptide P28 (mSIS/P28) as a novel GBR membrane for guided osteoporotic bone regeneration. These mSIS/P28 membranes were obtained through the mineralization of SIS (mSIS), followed by P28 loading onto heparinized mSIS. The heparinized mSIS membrane was designed to improve the immobilization efficacy and facilitate controlled release of P28. P28 release from mSIS-heparin-P28 and its effects on the proliferation, viability, and osteogenic differentiation of bone marrow stromal stem cells from ovariectomized rats (rBMSCs-OVX) were investigated in vitro. Furthermore, a critical-sized OVX calvarial defect model was used to assess the bone regeneration capability of mSIS-heparin-P28 in vivo. RESULTS: In vitro results showed that P28 release from mSIS-heparin-P28 occurred in a controlled manner, with a long-term release time of 40 days. Moreover, mSIS-heparin-P28 promoted cell proliferation and viability, alkaline phosphatase activity, and mRNA expression of osteogenesis-related genes in rBMSCs-OVX without the addition of extra osteogenic components. In vivo experiments revealed that mSIS-heparin-P28 dramatically stimulated osteoporotic bone regeneration. CONCLUSION: The heparinized mSIS loaded with P28 may serve as a potential GBR membrane for repairing osteoporotic defects.