Feasibility Analysis of 3D Printing-Assisted Pedicle Screw Correction Surgery for Degenerative Scoliosis.

Objective: To explore the feasibility of 3D printing-assisted pedicle screw correction surgery for degenerative scoliosis. Methods: From January 1, 2015 to January 31, 2020, patients with degenerative scoliosis who received corrective surgery in our hospital were retrospectively analyzed. Patients were grouped based on the fixation methods. Patients in the control group received traditional pedicle screw internal fixation, while those in the study group received 3D printing-assisted pedicle screw fixation. The therapeutic effects were compared. Results: There were 78 cases in the control group and 82 cases in the study group. There were no significant differences in scoliotic Cobb's angle, pelvic incidence-lumbar lordosis (PI-LL), VAS score, JOA score, social function, physical function, role function, or cognitive function between the study group and the control group before the surgery, but there were differences in the above parameters between the two groups after surgery. The incidence of postoperative complications in the study group was also significantly lower in the study group. Conclusion: 3D printing-assisted pedicle screw correction surgery provides a strong 3D correction force with reliable effect and fewer complications, and is a good treatment choice for degenerative scoliosis.

Full-endoscopic foraminoplasty for highly down-migrated lumbar disc herniation.

BACKGROUND AND STUDY AIMS: Multiple surgical approaches have been studied and accepted for the removal of highly downward migrated lumbar disc herniation (LDH). Here, we investigated the efficacy and safety of full-endoscopic foraminoplasty for highly downward migrated LDH. PATIENTS AND METHODS: Thirty-seven patients with highly down-migrated LDH treated by the full-endoscopic foraminoplasty between January 2018 and January 2020 were retrospectively investigated. Clinical parameters were evaluated preoperatively and 1, 6, and 12 months postoperatively, using pre- and post-operative Oswestry Disability Index (ODI) scores for functional improvement, visual analog scale (VAS) for leg and back pain, and modified MacNab criteria for patients satisfactory. RESULTS: Thirty-seven patients with highly downward migrated LDH were successfully removed via the transforaminal full-endoscopic discectomy. The average VAS back and leg pain scores were significantly reduced from 7.41 ± 1.17 and 8.68 ± 1.06 before operation to 3.14 ± 0.89 and 2.70 ± 0.46 at postoperative 1 month, and 1.76 ± 0.59 and 0.92 ± 0.28 at postoperative 12 months, respectively (P < 0.05). The average ODI scores were reduced from 92.86 ± 6.41 to 15.30 ± 4.43 at postoperative 1 month, and 9.81 ± 3.24 at postoperative 12 months (P < 0.05). Based on the modifed MacNab criteria, 36 out of 37 patients (97.30%) were rated as excellent or good outcomes. CONCLUSION: The full-endoscopic foraminoplasty can be used successfully for surgical removal of high grade down-migrated LDH, and it could serve as an efficient alternative technique for patients with highly downward migrated LDH.

An experimental study on the safe placement of sacroiliac screws using a 3D printing navigation module.

BACKGROUND: In this experimental study, we evaluated the use of digital 3D navigation printing in minimizing complications arising from sacroiliac screw misplacement. METHODS: A total of 13 adult pelvic specimens were studied using 3D navigation printing. Mimics software was used for preoperative planning and for obtaining sacrum median sagittal resection and long axis resection of the S1 pedicle center by 3D segmentation. The ideal screw path had its origin at the post-median part of the auricular surface of the sacroiliac joint, the midpoint at the mid-position of the lateral recess and outlet of the anterior sacral foramina; and the endpoint at the S1 sagittal resection. A sacroiliac screw fixed the pelvic specimens with the assistance of the navigation module. The distance between the start point (ilium surface) and endpoint (sacral median sagittal resection) of the screw path was measured after the pre- and postoperative 3D pelvis module was 3D-registered according to the standard precision range. The origin/endpoint qualified rates of the postoperative (n/26) and preoperative (26/26) screw paths were analyzed by the chi-square test. RESULTS: No screw misplacement occurred in the screw paths of any of the 13 pelvic specimens. The mean distance between the preoperative and postoperative origin of the screw path was 1.5415±0.6806 mm, and the mean distance between the preoperative and postoperative endpoint was 2.2809±0.4855 mm. The qualified rate of origin was 23/26 when the precision grade was 2.4 mm (P>0.05, χ2=1.41), while the qualified rate of endpoint was 21/26 when the precision grade was 2.7 mm (P>0.05, χ2=3.54). CONCLUSIONS: In this experimental study, using a 3D printing navigation module helped attain an accurate and safe sacroiliac screw implantation.

Design, application, and evaluation of a novel method for determining optimal trajectory of thoracic pedicle screws.

BACKGROUND: This is an experimental study performed on 15 adult cadavers. In this cadaveric study, we designed and evaluated a novel methodology for determining the optimal trajectory for the placement of thoracic pedicle screws. The accuracy of thoracic pedicle screw placement is critical to the spinal surgery. The concept, implement method, and significance of the optimal thoracic pedicle trajectory have not been reported. METHODS: The experimental study was performed on 15 adult cadavers. The Mimics software was used to design optimal trajectory through the pedicle central axis. Using three-dimensional (3D) printing, a navigation module with a locating facet and a stabilizing facet was developed. The thoracic pedicle screws were inserted with the help of the navigation module. The three-dimensional coordinates for the entry and the exit points of the screws were compared between the planned trajectories and the postoperative trajectories. The differences in coordinates were analyzed to evaluate the precision of the screw placement. RESULTS: The trajectories through the pedicle central axis showed an excellent symmetry between the single segments and for all thoracic vertebrae. Out of a total of 358 screws that were inserted, 15 (4.2%) screws breached the pedicle cortex with a breach distance of <2 mm. The qualifying rate was 98.6% (353/358) for the entry point precision of ≥3.2 mm, and 98.9% (354/358) for the exit point precision of ≥6.4 mm. In comparison to the designed qualified rate of 100% (358/358), the χ2 was 3.22 and 2.26, respectively (P>0.05). CONCLUSIONS: The optimal trajectory was obtained through the pedicle central axis, which significantly reduced the risk of cortex breach. A high degree of precision was obtained for the entry and the exit points of the screws when the postoperative trajectory was compared with the designed trajectory.

The construction of the scoliosis 3D finite element model and the biomechanical analysis of PVCR orthopaedy.

OBJECTIVE: The objective is to investigate the biomechanical conditions of the Posterior Vertebral Column Resection (PVCR) of the constructed scoliosis 3D finite element model. METHODS: A patient with scoliosis was selected; before the PVCR orthopaedy, the patient was submitted to the radiography of normal and lateral full-length vertebral column scans and the total magnetic resonance imaging (MRI) scans; then, the idiopathic scoliosis model was constructed by the 3D finite element method, and the 3D finite element software utilized in the process of model construction included Mimics software, Geomagic Studio 12 software, and Unigraphic 8.0 (UG 8.0) software; in addition, PVCR orthopaedy was utilized to correct the scoliosis of the patient, and the biomechanical parameters, such as orthodontic force, vertebral body displacement, orthopedic rod stress, stress on the pin-bone interface of the vertebral body surface, and the stress on the intervertebral disc, were studied. RESULTS: The 3D effective finite element model of scoliosis was successfully constructed by the Mimics software, the Geomagic Studio 12 software, and the UG 8.0 software, and the effectiveness was tested. PVCR orthopaedy could effectively solve the problem of scoliosis. The magnitude of the orthodontic force that a patient needed depended on the physical conditions and the personal orthodontic requirements of the patient. The maximum vertebral body displacement on the X-axis was the vertebral body L1, the maximum displacement on the Y-axis was the vertebral body T3, the maximum displacement on the Z-axis was the vertebral body T1, and the rang of orthopedic rod stress was 0.0050214e7 MPa to 0.045217e7 MPa, in which the maximum stress of 2 vertebral bodies in, above, and below the osteotomy area reached 0.045217e7 MPa, the stress on the pin-bone interface of the T10 vertebral body surface reached 11.83 MPa, and the stress of T8/T9 intervertebral disc reached 13.84 MPa. CONCLUSION: The 3D finite element model based on 3D finite element software was highly efficient, and its numerical simulation was accurate, which was important for the subsequent biomechanical analysis of PVCR orthopaedy. In addition, the vertebral stress of PVCR orthopaedy was different in each body part, which was mainly affected by the applied orthodontic force and the sites of the orthodontic area.

Oral vs intravenous tranexamic acid in total-knee arthroplasty and total hip arthroplasty: A systematic review and meta-analysis.

BACKGROUND: This study aimed to compare the efficacy and safety of oral tranexamic acid (TXA) with intravenous (IV) TXA in reducing perioperative blood loss in total-knee arthroplasty (TKA) and total-hip arthroplasty (THA). METHODS: PubMed, Web of Science, Embase, and Cochrane Library were fully searched for relevant studies. Studies comparing the efficacy and safety of oral TXA with IV TXA in TKA and THA were included in this research. Odds ratio (OR) or risk difference (RD) was applied to compare dichotomous variables, while mean difference (MD) was used to compare continues variables. RESULTS: A total of 7 studies (5 randomized controlled trials and 2 retrospective studies) were included into this study. As for patients undergoing TKA or THA, there were no obvious differences between oral TXA group and IV TXA group in hemoglobin (Hb) drop (MD = 0.06, 95% confidence interval [CI] = -0.01 to 0.13, P = .09), transfusion rate (OR = 0.78, 95% CI = 0.54-1.13, P = .19), total blood loss (MD = 16.31, 95% CI = -69.85 to 102.46, P = .71), total Hb loss (MD = 5.18, 95% CI = -12.65 to 23.02, P = .57), length of hospital stay (MD = -0.06, 95% CI = -0.30 to 0.18, P = .63), drain out (MD = 21.04, 95% CI = -15.81 to 57.88, P = .26), incidence of deep vein deep vein thrombosis (RD = 0.00, 95% CI = -0.01 to 0.01, P = .82) or pulmonary embolism (RD = 0.00, 95% CI = -0.01 to 0.01, P = .91). The sample size of this study was small and several included studies were with relatively low quality. CONCLUSION: Oral TXA is equivalent to IV TXA in reducing perioperative blood loss and should be recommended in TKA and THA. More high-quality studies are needed to elucidate this issue.

cPLA2a correlates with metastasis and poor prognosis of osteosarcoma by facilitating epithelial-mesenchymal transition.

BACKGROUND: Osteosarcoma (OS) patients with metastasis have very dismal prognoses, and lack effective target therapies. Overexpression of cytosolic phospholipase A2 (cPLA2) has been shown to promote progression in several types of cancers, but its functions in OS have not been investigated. MATERIALS AND METHODS: In our study, the expression of cPLA2a was detected with immunohistochemistry in 102 cases of OS. The clinical significance of cPLA2a was evaluated by analyzing its correlation with clinicopathological factors. The prognostic significance of cPLA2a was estimated by univariate and multivariate analysis. The oncogenic functions of cPLA2a on cell proliferation and invasion were investigated by MTT assay and tranwell assay respectively. Western blotting was applied to detect the markers of epithelial-mesenchymal transition (EMT) after silencing cPLA2a expression or inhibiting its activity by a specific antagonist. RESULTS: In our study, high expression of cPLA2a was significantly associated with metastasis and advanced Enneking stage. High cPLA2a expression was significantly associated with poor prognosis and it was an independent prognostic biomarker of OS. By silencing cPLA2a or inhibiting its activity by a specific antagonist, we demonstrated that cPLA2a promoted cell invasion of OS cells via inducing the EMT process. CONCLUSIONS: High cPLA2a expression was an independent prognostic biomarker of OS, and cPLA2a could promote OS cell invasion via inducing the EMT process, indicating that cPLA2a was an independent prognostic biomarker and may be an effective drug target for OS.

Searching for perturbed biological pathways and genes through analyzing the expression profile changes in osteoclasts after treatment by bisphosphonates.

Criticality pathways and genes related to osteoporosis were identified. We downloaded the expression data of osteoclasts treated with or without bisphosphonates and all human pathways from the public database. Gibbs sampling and Markov chain were performed to identify the disturbed pathways and the hub genes in the disturbed pathways. Pathways and genes with adjusted probability (αadj ) ≥0.75 were considered as the disturbed pathways and hub genes. We identified four disturbed pathways (Maturity onset diabetes of the young, Olfactory transduction, Cyanoamino acid metabolism, Taurine and hypotaurine metabolism) and two hub genes (OR2A4 and NKX2-2) with αadj ≥0.75. The expression levels of these disturbed pathways and hub genes were downregulated in bisphosphonates group. In conclusion, four disturbed pathways and two hub genes related to osteoporosis were identified. These results give us a better understanding of the potential mechanism of bisphosphonate treatment and the pathogenesis of osteoporosis.

Accurate placement of cervical pedicle screws using 3D-printed navigational templates : An improved technique with continuous image registration.

OBJECTIVE: Accurate placement of cervical pedicle screws remains a surgical challenge. This study aimed to test the feasibility of using a novel three-dimensional (3D-)printed navigational template to overcome this challenge. METHODS: Cervical spines were scanned using computed tomography (CT). A 3D model of the cervical spines was created. The screw trajectory was designed to pass through the central axis of the pedicle. Thereafter, a navigational template was designed by removing the soft tissue from the bony surface in the 3D model. A 3D printer was used to print the navigational template. The screws were then placed in the cadavers following CT scanning. The 3D model of the designed trajectory and the placed screws were registered. The coordinates of the entry and exit points of the designed trajectory and the actual trajectory were recorded. The numbers of qualified points that met the different degrees of accuracy were compared using a χ2 test. RESULTS: A total of 158 screws were placed. Five screws breached the pedicle cortex with a distance <2 mm. There was no significant difference between the pre- and postoperative entry points with a degree of accuracy ≥1.7 mm (P = 0.131). Meanwhile, there was no significant difference between the pre- and postoperative exit points with degrees of accuracy ≥6.4 mm (P = 0.071). CONCLUSION: A navigational template can be designed by removing the soft tissue from the bony surface in a CT-generated 3D model. This guiding tool may effectively prevent intraoperative drifting and accurately places cervical pedicle screws.

Application of a novel 3D drill template for cervical pedicle screw tunnel design: a cadaveric study.

PURPOSE: To develop and validate the efficacy and accuracy of a three-dimensional (3D) computed tomography (CT) reconstructive rapid prototyping drill template for cervical pedicle screw placement. METHODS: CT thin-layer scans were obtained from 12 adult cadaveric cervical specimens and reconstructed. The ideal screw channels were chosen by analyzing the cross sections of the reconstructed 3D images. The navigation templates were designed and printed based on the optimal screw channels. The pedicle screws were placed on the cadaver specimens under template guidance, and the cadaver specimens were scanned and reconstructed. The pre- and post-operative models were compared. Entry point and exit point data of these two models were collected and compared using the Chi-square test. RESULTS: A total of 164 cervical pedicle screws were placed; among them, six punctured the cortical bone of the vertebral pedicle reaching an accuracy of 96.3%. Among the outside screws, all of the deviation distances were <2 mm. The Chi-square test results showed that when a deviation of 1.2 mm was used as a standard for the entry point, there was no difference between the two groups (χ 2 = 1.346, p = 0.248); when a deviation of 2.2 mm was used as a standard for the exit point, there was no difference between the two groups (χ 2 = 3.250, p = 0.061). CONCLUSION: The 3D CT reconstructive rapid prototyping drill template combined with the screw tunnel design based on 3D cutting technique can help facilitate accurate cervical pedicle screw insertion.

Accurate fixation of plates and screws for the treatment of acetabular fractures using 3D-printed guiding templates: An experimental study.

OBJECTIVE: To investigate the feasibility of the use of 3D-printed guiding templates for accurate placement of plates and screws for internal fixation of acetabular fractures. METHODS: 3D models of the pelvises of 14 adult cadavers were reconstructed using computed tomography (CT). Twenty-eight acetabular fractures were simulated and placement positions for plates and screw trajectories were designed. Bending module was obtained by 3D cutting; guiding template was manufactured using 3D printing, and the plate was pre-bent according to the bending module. Plates and screws were placed in cadaveric pelvises using the guiding template, and 3D model was reconstructed using CT. The designed and real trajectories were matched using 3D registration including the coordinates (entry and exit points) of designed trajectory. The number of qualified points with different accuracy levels was compared using Chi-squared test. RESULTS: Sixty-four plates and 339 screws were placed with no cortical breach. The absolute difference of the X, Y, and Z coordinates between the designed and real entry points were 0.52±0.45, 0.43±0.36, and 0.53±0.44mm, respectively. The corresponding values for the exit points were 0.83±0.67, 1.22±0.87, and 1.26±0.83mm, respectively. With an accuracy degree ≥1.9mm for the entry points and ≥3.8mm for the exit points, there was no significant difference between the designed and the real trajectories. CONCLUSION: The 3D-printed guiding template helped achieve accurate placement of plates and screws in the pelvis of adult cadavers.

[Effectiveness of distal femoral osteotomy assisted by three-dimensional printing technology for correction of valgus knee with osteoarthritis].

Objective: To evaluate the effectiveness of distal femoral osteotomy aided by three-dimensional (3D) printing cutting block for correction of vaglus knee with osteoarthritis. Methods: Between January 2014 and January 2016, 12 patients (15 knees) with vaglus deformity and lateral osteoarhritis underwent medial closing wedge distal femoral osteotomy. There were 5 males and 7 females, aged 30-60 years (mean, 43.8 years). The mean disease duration was 6.6 years (range, 1-12 years). The unilateral knee was involved in 9 cases and bilateral knees in 3 cases. According to Koshino's staging system, 1 knee was classified as stage I, 9 knees as stage II, and 5 knees as stage III. The X-ray films of bilateral lower extremities showed that the femorotibial angle (FTA) and anatomical lateral distal femoral angle (aLDFA) were (160.40±2.69)° and (64.20±2.11)° respectively. Mimics software was used to design and print the cutting block by 3D printing technique. During operation, the best location of distal femoral osteotomy was determined according to the cutting block. After osteotomy, internal fixation was performed using a steel plate and screws. Results: All incisions healed primarily; no complication of infection or deep vein thrombosis was observed. All patients were followed up 6-18 month (mean, 12.2 months). At 6 months after operation, the hospital for special surgery (HSS) score for knee was significantly improved to 89.07±2.49 when compared with preoperative score (65.27±1.49, t=-28.31, P=0.00); the results were excellent in 10 knees, good in 4 knees, and fair in 1 knee with an excellent and good rate of 93.3%. The bony union time was 2.9-4.8 months (mean, 3.3 months). Bone delayed union occurred in 1 case (1 knee). The postoperative FTA and aLDFA were (174.00±1.41)° and (81.87±1.06)° respectively, showing significant differences when compared with preoperative ones ( t=-18.26， P=0.00; t=-25.19, P=0.00). The percentage of medial tibial plateau in whole tibial plateau was 49.78%±0.59%, showing no significant difference when compared with intraoperative measurement (49.82%±0.77%, t=0.14, P=0.89). Conclusion: 3D printing cutting block can greatly improve the accuracy of distal femoral osteotomy, and ensure better effectiveness for correction of vaglus knee with osteoarthritis.

[Clinical application of accurate placement of lumbar pedicle screws using three-dimensional printing navigational templates under Quadrant system].

Objective: To explore the feasibility and the effectiveness of the accurate placement of lumbar pedicle screws using three-dimensional (3D) printing navigational templates in Quadrant minimally invasive system. Methods: The L 1-5 spines of 12 adult cadavers were scanned using CT. The 3D models of the lumbar spines were established. The screw trajectory was designed to pass through the central axis of the pedicle by using Mimics software. The navigational template was designed and 3D-printed according to the bony surface where the soft tissues could be removed. The placed screws were scanned using CT to create the 3D model again after operation. The 3D models of the designed trajectory and the placed screws were registered to evaluate the placed screws coincidence rate. Between November 2014 and November 2015, 31 patients with lumbar instability accepted surgery assisted with 3D-printing navigation module under Quadrant minimally invasive system. There were 14 males and 17 females, aged from 42 to 60 years, with an average of 45.2 years. The disease duration was 6-13 months (mean, 8.8 months). Single segment was involved in 15 cases, two segments in 13 cases, and three segments in 3 cases. Preoperative visual analogue scale (VAS) was 7.59±1.04; Oswestry disability index (ODI) was 76.21±5.82; and the Japanese Orthopaedic Association (JOA) score was 9.21±1.64. Results: A total of 120 screws were placed in 12 cadavers specimens. The coincidence rate of placed screw was 100%. A total of 162 screws were implanted in 31 patients. The operation time was 65-147 minutes (mean, 102.23 minutes); the intraoperative blood loss was 50-116 mL (mean, 78.20 mL); and the intraoperative radiation exposure time was 8-54 seconds (mean, 42 seconds). At 3-7 days after operation, CT showed that the coincidence rate of the placed screws was 98.15% (159/162). At 4 weeks after operation, VAS, ODI, and JOA score were 2.24±0.80, 29.17±2.50, and 23.43±1.14 respectively, showing significant differences when compared with preoperative ones ( t=14.842, P=0.006; t=36.927, P=0.002; t=-36.031, P=0.001). Thirty-one patients were followed up 8-24 months (mean, 18.7 months). All incision healed by first intention, and no complication occurred. During the follow-up, X-ray film and CT showed that pedicle screw was accurately placed without loosening or breakage, and with good fusion of intervertebral bone graft. Conclusion: 3D-printing navigational templates in Quadrant minimally invasive system can help lumbar surgery gain minimal invasion, less radiation, and accurate placement.

Discovery of 2-((3-cyanopyridin-2-yl)thio)acetamides as human lactate dehydrogenase A inhibitors to reduce the growth of MG-63 osteosarcoma cells: Virtual screening and biological validation.

Lactate dehydrogenase A (LDHA) has emerged as an attractive target in the oncology field. In this paper, we present the identification of 2-((3-cyanopyridin-2-yl)thio)acetamide-containing compounds as LDHA inhibitors. The in vitro enzymatic assay suggested that inhibitor 9 had good inhibitory potency against LDHA with IC50 value as 1.24µM. Cytotoxicity assay showed that inhibitor 9 strongly inhibited the proliferation of cancer cell MG-63 (EC50=0.98µM). These findings indicated that inhibitor 9 could be employed as a lead for developing more potent LDHA inhibitor with anti-proliferative potency.

[EFFECTIVENESS OF HIGH TIBIAL OSTEOTOMY ASSISTED BY THREE- DIMENSIONAL PRINTING TECHNOLOGY FOR CORRECTION OF VARUS KNEE WITH OSTEOARTHRITIS].

OBJECTIVE: To evaluate the effectiveness of high tibial osteotomy (HTO) assisted by three-dimensional (3-D) printing technology for correction of varus knee with osteoarthritis. METHODS: Between January 2014 and June 2015, 16 patients (20 knees) with varus knee and osteoarthritis underwent HTO assisted by 3-D printing technology; a locking compression plate was used for internal fixation after HTO. There were 6 males and 10 females, aged 30-60 years (mean, 45.5 years). The disease duration was 1-10 years (mean, 6.2 years). The unilateral knee was involved in 12 cases and bilateral knees in 4 cases. According to Koshino's staging system, 3 knees were classified as stage I, 7 knees as stage II, 8 knees as stage III, and 2 knees as stage IV. Preoperative Hospital for Special Surgery (HSS) knee score was 63.8 ± 2.2; the femorotibial angle was (184.8 ± 2.9)°; and Insall-Salvati index was 1.03 ± 0.13. RESULTS: All the wounds healed primarily, and no complication of infection, osteofacial compartment syndrom, or deep vein thrombosis was observed. All patients were followed up 6-18 months (mean, 12.6 months). Personal paralysis was observed in 1 case (1 knee), and was cured after expectant treatment. Bone union time was 2.7-3.4 months (mean, 2.9 months). At 6 months after operation, the femorotibial angle was (173.8 ± 2.0)°, showing significant difference when compared with preoperative one (t = 11.70, P = 0.00); Insall-Salvati index was 1.04 ± 0.12, showing no significant difference when compared with preoperative one (t = -0.20, P = 0.85); and HSS knee score was significantly increased to 88.9 ± 3.1 (t = -25.44, P = 0.00). At last follow-up, the results were excellent in 13 knees, good in 6 knees, fair in 1 knee, and the excellent and good rate was 95%. CONCLUSION: 3-D printing cutting block can greatly improve the accuracy of HTO, avoid repeated X-ray and multiple osteotomy, shorten the operation time, and ensure better effectiveness for correction of varus knee with osteoarthritis.

[Digital design of internal fixation for distal femoral fractures via 3D printing and standard parts database].

OBJECTIVE: To study the method of internal fixation by the navigation embedded plate from standard parts database for the distal femoral fractures based on digital design by Mimics software with 3D printing technology, and to explore its feasibility and accuracy. METHODS: A total of 21 cases with distal femoral fractures admitted into the Department of Orthopedics, Affiliated Hospital of Putian University were included in this study. Dicom format data of lamellar CT scanning was imported into Mimics software for 3D anatomical modeling and virtual fracture reduction. The steel plates was chose from standard parts database for virtual internal fixation, and to design the navigation module with screw. 3D printing skeleton, steel plates, navigation module, internal fixation implants were simulated based on the printed bones model. Locations of steel plates and screws were determined by the navigation module. Then the sticking effects of navigation module, screws position and postoperative appearance were observed. After second CT scan and 3D reconstruction, 3D registration was performed to obtain the data of the three-dimensional coordinate values of screws entrance points and piercing points to analyze the results. RESULTS: A total of 21 plates and 180 screws were placed with the assistance of navigation module. CT scanning and 3D reconstruction was performed in twenty-one cases of postoperative bone model. The position of plates was in high accordance with the digital design by Mimics software. There were no significant differences between spatial location of screw entrance points and piercing points. The real operation was quite consistent with preoperative design. Navigation module and the corresponding distal femur bony structure jointed closely. The sticking effects and stability of navigation module were good, which was able to guide placement of steel plates and screws. CONCLUSION: These methods can enhance the accuracy of internal fixation of the standard parts database steel plate in distal femur fractures, with the assistance of navigation module.

[DIGITAL DESIGN OF STANDARD PARTS DATABASE FOR PROXIMAL TIBIA FRACTURES TREATED WITH PLATING VIA THREE-DIMENSIONAL PRINTING].

OBJECTIVE: To explore the method and feasibility of digital internal fixation for proximal tibia fractures using standard parts database and three-dimensional (3D) printing technology. METHODS: Ten adult lower extremity specimens were selected to take continuously thin-layer scanning. After Dicom image was imported into the Mimics software, the model of Schatzker II-VI types proximal tibia fracture was established, 2 cases each type. The virtual internal fixation was performed with plate and screw from standard parts database. The pilot hole of the navigation module design was printed by 3D printing technique. The plate and screw were inserted by the navigation module. X-ray film and CT were taken postoperatively to observe the position. Thirty patients with proximal tibia fracture underwent digital internal fixation using standard parts database and 3D printing technology (study group), and another 30 patients underwent traditional open reduction and internal fixation (control group). There was no significant difference in sex, age, side, causes, fracture classification, associated injury, and course of disease between 2 groups (P > 0.05). The preparative time, incision length, fracture healing time, operation time, and intraoperative blood loss were recorded. Follow up of imaging evaluation, clinical efficacy was evaluated by MacNab criteria. RESULTS: The navigation models were designed to fit the bony structure of proximal tibia and to guide implant insertion. The parameters of orientation, length, diameter, and angle were consistent with the preoperative plan. No statistically significant difference was found in the preparative times of pre-operation between 2 groups (t = 1.393, P = 0.169). The incision length, wound healing time, blood loss, operation time, and the cost of treatment in study group were significantly less than those in control group (P < 0.05). All patients were followed up 12-16 months (mean, 13.5 months). The fracture healing time of study group was significantly shorter than that of control group (t = 4.070, P = 0.000). At 12 months postoperatively, there was no significant difference in the efficacy based on MacNab criteria between 2 groups (U = 377.000, P = 0.238). CONCLUSION: Digital internal fixation for proximal tibia fractures using standard parts database and 3D printing technology has the advantages of short process, less blood loss, high safety and rapid fracture healing.

The relationship between the g.27450A>T genetic variant of OPG gene and osteoporosis in Chinese postmenopausal women.

The objective of this study is to evaluate the relationship between the g.27450A>T genetic variant of osteoprotegerin (OPG) gene and osteoporosis in Chinese postmenopausal women. A total of 886 subjects were enrolled in this study. The femoral neck hip, lumbar spine (L2-4), and total hip bone mineral density (BMD) were detected by dual-energy X-ray absorptiometry (DEXA). The genotyping of the g.27450A>T genetic variant of OPG gene was investigated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing methods. Significant differences in the femoral neck hip, lumbar spine (L2-4), and total hip BMD among different genotypes were found, and the subjects with AA genotype were significantly higher than those of AT and TT genotypes (P<0.05). The allele-A could be a decreased risk factor for osteoporosis. Results from this study support that the g.27450A>T genetic variant of OPG gene has potential relationship with BMD and osteoporosis in Chinese postmenopausal women.

Detection of urine C2C and trace element level in patients with knee osteoarthritis.

The objective is to determine the relation between severity of knee osteoarthritis (KOA) and levels of Collagen type II metabolite (C2C) and trace elements in the urine. The urine sample and knee joint films (anteroposterior and lateral) from the KOA patients and control subjects were collected. The KOA patients were divided into five groups (controls and grades I-IV) according to the Kellgren-Lawrence radiographic grading standards. Urine levels of C2C and trace elements were detected by enzyme-linked immunosorbent assay and inductively coupled plasma atomic emission spectrometry, respectively. Urine C2C levels in the KOA subjects (261.235 ± 39.944 pg/ml) were higher than those of the control group (218.341 ± 22.270 pg/ml). The Fe content in KOA groups was significantly lower than that of control group (group IV > group III > group II > group I or controls). The contents of Cu and Zn were also significantly higher in the KOA patients than in the control group (p < 0.05). However, Cr, Al, Cd, Ni, and Se levels of KOA patients were not significantly different from those of the controls (p > 0.05). Determination of the urine levels of C2C and trace elements may prove to be informative for an early diagnosis of KOA. It can also assist in the prognosis judgment of the disease and selecting an appropriate therapeutic regimen.

Short-term effect of unilateral pedicle screw fixed intervertebral fusion in treatment of degenerative disc disease via MAST QUADRANT minimally invasive system.

To assess the short-term outcome of unilateral pedicle screw fixed intervertebral fusion surgery for degenerative disc disease via MAST QUADRANT minimally invasive system. Thirty patients with degenerative lumbar disease from September 2009 to September 2011 were enrolled and divided into two groups: (1) unilateral pedicle screw fixed intervertebral fusion via MAST QUADRANT system; and (2) conventional bilateral pedicle fixed intervertebral fusion via open surgery. The perioperative parameters (operation time, intraoperative blood loss, and length of stay) and the follow-up clinical curative effect parameters (VAS and ODI) were compared between two groups. All patients successfully completed surgery and were followed up for more than 1 year. The perioperative parameters of MAST QUADRANT system group were significantly better than the control group (P < 0.05). And the clinical curative effects were similar to conventional surgery (P > 0.05). Unilateral pedicle screw fixed intervertebral fusion via MAST QUADRANT system is a less invasive and safer surgical techniques. It offers a quick recovery and effective surgical option in the treatment of lumbar degenerative diseases.