Comparison of Fusion Rate and Clinical Outcomes in Minimally Invasive and Conventional Posterior Fusion for Lumbar Degenerative Disease: A Network Meta-Analysis.

BACKGROUND: The fusion rate, clinical efficacy, and complications of minimally invasive fusion surgery and open fusion surgery in the treatment of lumbar degenerative disease are still unclear. METHODS: We conducted a literature search using PubMed, Embase, Cochrane Library, CNKI, and WANFANG databases. RESULTS: This study included 38 retrospective studies involving 3097 patients. Five intervention modalities were considered: unilateral biportal endoscopic-lumbar interbody fusion (UBE-LIF), percutaneous endoscopic-lumbar interbody fusion (PE-LIF), minimally invasive-transforaminal lumbar interbody fusion (MIS-TLIF), transforaminal lumbar interbody fusion (TLIF), and posterior lumbar interbody fusion (PLIF). Quality assessment indicated that each study met acceptable quality standards. PE-LIF demonstrated reduced low back pain (Odds Ratio = 0.50, Confidence Interval: 0.38-0.65) and lower complication rate (Odds Ratio = 0.46, Confidence Interval: 0.25-0.87) compared to PLIF. However, in indirect comparisons, PE-LIF showed the lowest fusion rates, with the ranking as follows: UBE-LIF (83.2%) > MIS-TLIF (59.6%) > TLIF (44.3%) > PLIF (39.8%) > PE-LIF (23.1%). With respect to low back pain relief, PE-LIF yielded the best results, with the order of relief as follows: PE-LIF (96.4%) > MIS-TLIF (64.8%) > UBE-LIF (62.6%) > TLIF (23.0%) > PLIF (3.2%). Global and local consistency tests showed satisfactory results, and heterogeneity tests indicated good stability. CONCLUSIONS: Compared to conventional open surgery, minimally invasive fusion surgery offered better scores for low back pain and Oswestry Disability Index, lower complication rates, reduced bleeding, and shorter hospital stays. However, minimally invasive fusion surgery did not show a significant advantage in terms of fusion rate and had a longer operative time.

Clinical efficacy and complications of MIS-TLIF and TLIF in the treatment of upper lumbar disc herniation: a comparative study.

BACKGROUND: The optimal treatment modality for upper lumbar disc herniation remains unclear. Herein, we compared the clinical efficacy and application value of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and transforaminal lumbar interbody fusion (TLIF) for upper lumbar disc herniation. We aimed to provide new evidence to guide surgical decisions for treating this condition. METHODS: We retrospectively analyzed the clinical data of 81 patients with upper lumbar disc herniation admitted between January 2017 and July 2018, including 41 and 40 patients who underwent MIS-TLIF and TLIF, respectively. Demographic characteristics, preoperative functional scores, perioperative indicators, and postoperative complications were compared. We performed consecutive comparisons of visual analog scale (VAS) scores of the lumbar and leg regions, Oswestry disability index (ODI), Japanese Orthopaedic Association scores (JOA), and MacNab scores at the final follow-up, to assess clinical outcomes 5 years postoperatively. RESULTS: VAS scores of the back and legs were significantly lower in the MIS-TLIF than the TLIF group at 3 months and 1 year postoperatively (P < 0.05). Intraoperative bleeding and postoperative hospitalization time were significantly lower, and the time to return to work/normal life was shorter in the MIS-TLIF than in the TLIF group (P < 0.05). The differences in JOA scores and ODI scores between the two groups at 3 months, 1 year, and 3 years postoperatively were statistically significant (P < 0.05). CONCLUSION: The early clinical efficacy of MIS-TLIF was superior to that of TLIF, but no differences were found in mid-term clinical efficacy. Further, MIS-TLIF has the advantages of fewer medical injuries, shorter hospitalization times, and faster postoperative functional recovery.

Three-Dimensional-Printed Spherical Hollow Structural Scaffolds for Guiding Critical-Sized Bone Regeneration.

The treatment of bone tissue defects continues to be a complex medical issue. Recently, three-dimensional (3D)-printed scaffold technology for bone tissue engineering (BTE) has emerged as an important therapeutic approach for bone defect repair. Despite the potential of BTE scaffolds to contribute to long-term bone reconstruction, there are certain challenges associated with it including the impediment of bone growth within the scaffolds and vascular infiltration. These difficulties can be resolved by using scaffold structural modification strategies that can effectively guide bone regeneration. This study involved the preparation of biphasic calcium phosphate spherical hollow structural scaffolds (SHSS) with varying pore sizes using 3D printing (photopolymerized via digital light processing). The chemical compositions, microscopic morphologies, mechanical properties, biocompatibilities, osteogenic properties, and impact on repairing critical-sized bone defects of SHSS were assessed through characterization analyses, in vitro cytological assays, and in vivo biological experiments. The results revealed the biomimetic properties of SHSS and their favorable biocompatibility. The scaffolds stimulated cell adhesion, proliferation, differentiation, and migration and facilitated the expression of osteogenic genes and proteins, including Col-1, OCN, and OPN. Furthermore, they could effectively repair a critical-sized bone defect in a rabbit femoral condyle by establishing an osteogenic platform and guiding bone regeneration in the defect region. This innovative strategy presents a novel therapeutic approach for assessing critical-sized bone defects.

A multifunctional biomimetic nanoplatform for image-guideded photothermal-ferroptotic synergistic osteosarcoma therapy.

Much effort has been devoted to improving treatment efficiency for osteosarcoma (OS). However, most current approaches result in poor therapeutic responses, thus indicating the need for the development of other therapeutic options. This study developed a multifunctional nanoparticle, PDA-MOF-E-M, an aggregation of OS targeting, programmed death targeting, and near-infrared (NIR)-aided targeting. At the same time, a multifunctional nanoparticle that utilises Fe-MOFs to create a cellular iron-rich environment and erastin as a ferroptosis inducer while ensuring targeted delivery to OS cells through cell membrane encapsulation is presented. The combination of PDA-MOF-E-M and PTT increased intracellular ROS and LPO levels and induced ferroptosis-related protein expression. A PDA-based PTT combined with erastin showed significant synergistic therapeutic improvement in the anti-tumour efficiency of the nanoparticle in vitro and vivo. The multifunctional nanoparticle efficiently prevents the osteoclasia progression of OS xenograft bone tumors in vivo. Finally, this study provides guidance and a point of reference for clinical approaches to treating OS.

Comparison between oblique lumbar interbody fusion and posterior lumbar interbody fusion for the treatment of lumbar degenerative diseases: a systematic review and meta-analysis.

BACKGROUND: Although oblique lumbar interbody fusion (OLIF) has produced good results for lumbar degenerative diseases (LDDs), its efficacy vis-a-vis posterior lumbar interbody fusion (PLIF) remains controversial. This meta-analysis aimed to compare the clinical efficacy of OLIF and PLIF for the treatment of LDDs. METHODS: A comprehensive assessment of the literature was conducted, and the quality of retrieved studies was assessed using the Newcastle-Ottawa Scale. Clinical parameters included the visual analog scale (VAS), and Oswestry Disability Index (ODI) for pain, disability, and functional levels. Statistical analysis related to operative time, intraoperative bleeding, length of hospital stay, lumbar lordosis angle, postoperative disc height, and complication rates was performed. The PROSPERO number for the present systematic review is CRD42023406695. RESULTS: In total, 574 patients (287 for OLIF, 287 for PLIF) from eight studies were included. The combined mean postoperative difference in ODI and lumbar VAS scores was - 1.22 and - 0.43, respectively. In postoperative disc, height between OLIF and PLIF was 2.05. The combined advantage ratio of the total surgical complication rate and the mean difference in lumbar lordosis angle between OLIF and PLIF were 0.46 and 1.72, respectively. The combined mean difference in intraoperative blood loss and postoperative hospital stay between OLIF and PLIF was - 128.67 and - 2.32, respectively. CONCLUSION: Both the OLIF and PLIF interventions showed good clinical efficacy for LDDs. However, OLIF demonstrated a superior advantage in terms of intraoperative bleeding, hospital stay, degree of postoperative disc height recovery, and postoperative complication rate.

Application of photocrosslinkable hydrogels based on photolithography 3D bioprinting technology in bone tissue engineering.

Bone tissue engineering (BTE) has been proven to be an effective method for the treatment of bone defects caused by different musculoskeletal disorders. Photocrosslinkable hydrogels (PCHs) with good biocompatibility and biodegradability can significantly promote the migration, proliferation and differentiation of cells and have been widely used in BTE. Moreover, photolithography 3D bioprinting technology can notably help PCHs-based scaffolds possess a biomimetic structure of natural bone, meeting the structural requirements of bone regeneration. Nanomaterials, cells, drugs and cytokines added into bioinks can enable different functionalization strategies for scaffolds to achieve the desired properties required for BTE. In this review, we demonstrate a brief introduction of the advantages of PCHs and photolithography-based 3D bioprinting technology and summarize their applications in BTE. Finally, the challenges and potential future approaches for bone defects are outlined.

Biomechanical studies of different numbers and positions of cage implantation on minimally invasive transforaminal interbody fusion: A finite element analysis.

Background: The position and number of cages in minimally invasive transforaminal interbody fusion (MIS-TLIF) are mainly determined by surgeons based on their individual experience. Therefore, it is important to investigate the optimal number and position of cages in MIS-TLIF. Methods: The lumbar model was created based on a 24-year-old volunteer's computed tomography data and then tested using three different cage implantation methods: single transverse cage implantation (model A), single oblique 45° cage implantation (model B), and double vertical cage implantation (model C). A preload of 500 N and a moment of 10 Nm were applied to the models to simulate lumbar motion, and the models' range of motion (ROM), ROM ratio, peak stress of the internal fixation system, and cage were assessed. Results: The ROM ratios of models A, B, and C were significantly reduced by >71% compared with the intact model under all motions. Although there were subtle differences in the ROM ratio for models A, B, and C, the trends were similar. The peak stress of the internal fixation system appeared in model B of 136.05 MPa (right lateral bending), which was 2.07 times that of model A and 1.62 times that of model C under the same condition. Model C had the lowest cage stress, which was superior to that of the single-cage model. Conclusion: In MIS-TLIF, single long-cage transversal implantation is a promising standard implantation method, and double short-cage implantation is recommended for patients with severe osteoporosis.

The Characteristic and Distribution of Shale Micro-Brittleness Based on Nanoindentation.

Shale is a special kind of rock mass and it is particularly important to evaluate its brittleness for the extraction of gas and oil from nanoporous shale. The current brittleness studies are mostly macro-evaluation methods, and there is a lack of a micro-brittleness index that is based on nanoindentation tests. In this paper, nanoindentation tests are carried out on the surface of shale to obtain mechanical property, and then a novel micro-brittleness index is proposed. Drawing a heat map by meshing indentation, the distribution characteristics of the brittleness index for the surface of shale and the variation laws between the mineral and brittleness index are explored. The results showed that the dimensionless brittleness index involved parameters including indentation irreversible deformation, elastic modulus, hardness and fracture toughness. The micro-brittleness index of the shale ranged from 7.46 to 65.69, and the average brittleness index was 25.837. The brittleness index exhibited an obvious bimodal distribution and there was great heterogeneity on the surface of shale. The crack propagation channels were formed by connecting many indentation points on the shale surface with high brittleness. The total brittleness index of quartz minerals was high, but the cementation effect with different minerals was various. Although the general brittleness of clay was low, the high brittleness index phenomenon was also exhibited. Studying the micro-brittleness of shale provides a more detailed evaluation for the shale friability, which is used to determine the optimal shale oil and gas recovery regime.

Feasibility Study of a Novel Magnetic Bone Cement for the Treatment of Bone Metastases.

Bone cement is a crucial material to treat bone metastases defects, and can fill the bone defect and provide mechanical support simultaneously, but the antitumor effect is very limited. Magnetic bone cement not only supports bone metastasis defects but can also achieve magnetic hyperthermia to eliminate tumor cells around the bone defect. However, the physicochemical properties of the bone cement matrix will change if the weight ratio of the magnetic nanoparticles in the cement is too high. We mixed 1 weight percent Zn0.3Fe2.7O4 with good biocompatibility and high heating efficiency into a polymethyl methacrylate matrix to prepare magnetic bone cement, which minimized the affection for physicochemical properties and satisfied the hyperthermia requirement of the alternating magnetic field.

Characterization and Biomechanical Study of a Novel Magnesium Potassium Phosphate Cement.

Magnesium potassium phosphate cement (MKPC) has attracted considerable attention as a bone regeneration material. However, there are only a few reports on its biomechanical properties. To evaluate the biomechanical properties of MKPC, we compared the mechanical parameters of pedicle screws enhanced with either MKPC or polymethyl methacrylate (PMMA) bone cement. The results show that the maximum pull-out force of the pedicle screws was 417.86 ± 55.57 and 444.43 ± 19.89 N after MKPC cement setting for 30 min and 12 h, respectively, which was better than that of the PMMA cement. In fatigue tests, the maximum pull-out force of the MKPC cement group was 435.20 ± 7.96 N, whereas that of the PMMA cement in the control group was 346.80 ± 7.66 N. Furthermore, the structural characterization analysis of the MKPC cement revealed that its microstructure after solidification was an irregular tightly packed crystal, which improved the mechanical strength of the cement. The maximum exothermic temperature of the MKPC reaction was 45.55 ± 1.35 °C, the coagulation time was 7.89 ± 0.37 min, and the compressive strength was 48.29 ± 4.76 MPa, all of which meet the requirements of clinical application. In addition, the MKPC cement did not significantly inhibit cell proliferation or increase apoptosis, thus indicating good biocompatibility. In summary, MKPC exhibited good biomechanical properties, high initial strength, good biocompatibility, and low exothermic reaction temperature, demonstrating an excellent application potential in the field of orthopedics.

Finite Element Analysis of a Novel Fusion Strategy in Minimally Invasive Transforaminal Lumbar Interbody Fusion.

Purpose: To evaluate the biomechanics of a novel fusion strategy (hybrid internal fixation+horizontal cage position) in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Methods: MIS-TLIF finite element models for three fusion strategies were created based on computed tomography images, namely, Model-A, hybrid internal fixation (ipsilateral pedicle screw and contralateral translaminar facet screw fixation)+horizontal cage position; Model-B, bilateral pedicle screw (BPS) fixation+horizontal cage position; and Model-C, BPS fixation+oblique 45° cage position. A preload of 500 N and a moment of 10 Nm were applied to the models to simulate lumbar motion, and the models' range of motion (ROM), peak stress of the internal fixation system, and cage were assessed. Results: The ROM for Models A, B, and C were not different (P > 0.05) but were significantly lower than the ROM of Model-INT (P < 0.0001). Although there were subtle differences in the ROM ratio for Models A, B, and C, the trend was similar. The peak stress of the internal fixation system was significantly higher in Model-A than that of Models B and C, but only the difference between Models A and B was significant (P < 0.05). The peak stress of the cage in Model-A was significantly lower than that of Models B and C (P < 0.01). Conclusion: Hybrid internal fixation with horizontal single cage implantation can provide the same biomechanical stability as traditional fixation while reducing peak stress on the cage and vertebral endplate.

Rapidly Progressive Paraplegia Resulting from Latent Cervical Dural Arteriovenous Fistula After Lumbar Surgery: A Case Report.

CASE: A 68-year-old woman developed symptoms of acute paraplegia due to an occult cervical dural arteriovenous fistula (DAVF) after a minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). She was subsequently diagnosed by angiography and treated with vascular embolization. A 2-year follow-up showed that the patient's upper limb muscle strength returned to normal, and the lower limb muscle strength partially improved with remnant motor dysfunction. CONCLUSION: For patients with symptoms of nerve injury inconsistent with the spinal surgery site, a possibility of DAVF should be considered, and related investigations should be performed. Once diagnosed, active treatment is required.

[Comparison of minimally invasive transforaminal lumbar interbody fusion between two approaches in treatment of single-segment lumbar spinal stenosis].

OBJECTIVE: To compare the effectiveness of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with bilateral decompression via unilateral approach and bilateral decompression via bilateral approaches in the treatment of single-segment lumbar spinal stenosis. METHODS: Between February 2015 and January 2017, 70 cases of single-segment lumbar spinal stenosis were treated with MIS-TLIF. The bilateral decompression via unilateral approach (group U) was performed in 36 cases and bilateral decompression via bilateral approaches (group B) in 34 cases. There was no significant difference in age, gender, body mass index, disease duration, distribution of responsibility segments, preoperative visual analogue scale (VAS) score of low back pain and leg pain and Oswestry disability index (ODI) score ( P>0.05). The operation time, intraoperative blood loss, hospitalization stay after operation, complications related to operation, incidence of asymptomatic lateral root symptoms, VAS scores of low back pain and leg pain, and ODI score before and after operation were compared between the two groups. X-ray film and CT scan at 12 months after operation were used to assessted the intervertebral bony fusion. RESULTS: The operation time and intraoperative blood loss in group U were significantly less than those in group B ( P<0.05). There was no significant difference in hospitalization stay after operation between the two groups ( t=-0.311, P=0.757). During the operation, 1 case in group U and 2 cases in group B had dural tear. No screw placement related nerve injury or asymptomatic lateral root symptoms occurred after operation. The patients were followed up 24 to 38 months, with an average of 32.8 months in group U and 35.5 months in group B. The VAS scores of low back pain and leg pain at 2 days, 3, 6, and 12 months after operation were significantly lower than that before operation in the two groups ( P<0.05), and there was no significant difference between the two groups ( P>0.05). The ODI scores at 3, 6 and 12 months after operation were significantly lower than that before operation in the two groups ( P<0.05), and there was no significant difference between the two groups ( P>0.05). Radiographic examination showed interbody fusion at 12 months after operation in the two groups. CONCLUSION: MIS-TLIF is safe and effective in the treatment of single-segment lumbar spinal stenosis with bilateral decompression via unilateral approach and bilateral decompression via bilateral approaches. Bilateral decompression via unilateral approach takes less operation time and has less intraoperative blood loss.

A novel 3D printed cage with microporous structure and in vivo fusion function.

In this study, a novel 3D printed porous titanium cage (3D printed cage) with interconnected pores inside was designed and manufactured. Observations by scanning electron microscopy showed that the inside of the 3D printed cage had an octahedral porous structure, with the pores uniform in size and connected to each other. The mechanical properties analysis found that the Young's modulus and compressive strength of the porous structure were close to those of the bone structure, and the overall stiffness was slightly higher than that of the polyether ether ketone (PEEK) material, but was significantly lower than that of the titanium alloy solid module. Animal experiments indicated that the new 3D printed cage was equivalent to PEEK cage in fusion time. At 3 months, the new bone grew into the cage through the pores of the new 3D printed cage surface, which had a high bone contact rate. These results demonstrate that the 3D printed porous titanium cage has good biocompatibility and osseointegration, and has a potential clinical value as bone implants. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Maximizing Specific Loss Power for Magnetic Hyperthermia by Hard-Soft Mixed Ferrites.

Maximized specific loss power and intrinsic loss power approaching theoretical limits for alternating-current (AC) magnetic-field heating of nanoparticles are reported. This is achieved by engineering the effective magnetic anisotropy barrier of nanoparticles via alloying of hard and soft ferrites. 22 nm Co0.03 Mn0.28 Fe2.7 O4 /SiO2 nanoparticles reach a specific loss power value of 3417 W g-1metal at a field of 33 kA m-1 and 380 kHz. Biocompatible Zn0.3 Fe2.7 O4 /SiO2 nanoparticles achieve specific loss power of 500 W g-1metal and intrinsic loss power of 26.8 nHm2 kg-1 at field parameters of 7 kA m-1 and 380 kHz, below the clinical safety limit. Magnetic bone cement achieves heating adequate for bone tumor hyperthermia, incorporating an ultralow dosage of just 1 wt% of nanoparticles. In cellular hyperthermia experiments, these nanoparticles demonstrate high cell death rate at low field parameters. Zn0.3 Fe2.7 O4 /SiO2 nanoparticles show cell viabilities above 97% at concentrations up to 500 µg mL-1 within 48 h, suggesting toxicity lower than that of magnetite.