SSR1 and CKAP4 as potential biomarkers for intervertebral disc degeneration based on integrated bioinformatics analysis.

Background: Intervertebral disc degeneration (IDD) is a significant cause of low back pain and poses a significant public health concern. Genetic factors play a crucial role in IDD, highlighting the need for a better understanding of the underlying mechanisms. Aim: The aim of this study was to identify potential IDD-related biomarkers using a comprehensive bioinformatics approach and validate them in vitro. Materials and Methods: In this study, we employed several analytical approaches to identify the key genes involved in IDD. We utilized weighted gene coexpression network analysis (WGCNA), MCODE, LASSO algorithms, and ROC curves to identify the key genes. Additionally, immune infiltrating analysis and a single-cell sequencing dataset were utilized to further explore the characteristics of the key genes. Finally, we conducted in vitro experiments on human disc tissues to validate the significance of these key genes in IDD. Results: we obtained gene expression profiles from the GEO database (GSE23130 and GSE15227) and identified 1015 DEGs associated with IDD. Using WGCNA, we identified the blue module as significantly related to IDD. Among the DEGs, we identified 47 hub genes that overlapped with the genes in the blue module, based on criteria of |logFC| ≥ 2.0 and p.adj <0.05. Further analysis using both MCODE and LASSO algorithms enabled us to identify five key genes, of which CKAP4 and SSR1 were validated by GSE70362, demonstrating significant diagnostic value for IDD. Additionally, immune infiltrating analysis revealed that monocytes were significantly correlated with the two key genes. We also analyzed a single-cell sequencing dataset, GSE199866, which showed that both CKAP4 and SSR1 were highly expressed in fibrocartilage chondrocytes. Finally, we validated our findings in vitro by performing real time polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) on 30 human disc samples. Our results showed that CKAP4 and SSR1 were upregulated in degenerated disc samples. Taken together, our findings suggest that CKAP4 and SSR1 have the potential to serve as disease biomarkers for IDD.

Ex vivo evaluation of a percutaneous thread-transecting technique for desmotomy of normal palmar/plantar annular ligaments in horses.

OBJECTIVE: To develop and describe a minimally invasive, ultrasound-guided, percutaneous technique for the desmotomy of equine palmar/plantar annular ligaments (PALs) using a transecting thread. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Twenty-one normal equine distal limb specimens. METHODS: Under ultrasonographic guidance, a surgical thread was percutaneously placed around the PAL through 2 skin punctures (proximal and distal) using a 18 gauge spinal needle in equine limbs (11 forelimbs, 10 hindlimbs) with normal PALs. The ligament was transected by a back-and-forth motion of the thread until the loop emerged from the proximal skin puncture site. Each specimen was dissected and assessed for completeness of transection and iatrogenic damage under direct visualization. Descriptive statistics were reported. RESULTS: The PAL was completely transected in 17/21 limbs. The mean duration of the procedure was 16 minutes. Superficial needle puncture or subtle abrasion of the superficial digital flexor tendon was noticed in 4 limbs. No iatrogenic injury to other intrathecal structures was identified. After PAL division, the needle entry and exit points had a mean diameter of 1.2 and 1 mm, respectively. CONCLUSION: Desmotomy of normal PALs in equine limb specimens was performed effectively using the percutaneous thread-transecting technique with minimal iatrogenic damage to adjacent structures. CLINICAL SIGNIFICANCE: Information from this study will allow refinement of the technique for use in equine clinical cases either in standing or anesthetized horses.

Long-Term Outcomes of Peripheral Pulmonary Cement Embolism in Patients with Polymethylmethacrylate Augmentation: A Case Series with a Minimum Follow-Up of Five Years.

BACKGROUND: Pulmonary cement embolism (PCE) is a rare but lethal complication. However, few long-term follow-up studies have investigated PCE after polymethylmethacrylate augmentation. This study aimed to investigate both the clinical and imaging outcomes of patients with PCE during a follow-up period of at least 5 years. METHODS: A total of 1460 patients were initially included in this retrospective study. After exclusion, the clinical and imaging data were analyzed for selected patients, including the augmented level, location and length of the PCE, symptoms, therapy, migration and disintegration of the embolism, foreign body reaction, and status at follow-up. RESULTS: Twelve female patients (age range, 56-88 years) with PCE and more than 5 years of follow-up (range, 5-13 years) were eventually included. All emboli were found in subsegment pulmonary arteries and were classified as peripheral PCE. Although 2 patients experienced transient symptoms after surgery, the majority of patients (84.6%) were asymptomatic during follow-up. No other reported emboli were observed during the follow-up period. The imaging data showed that the cement embolus could remain in the initial position throughout the long-term follow-up. In terms of the length of the PCE, there was no statistically significant difference between the values post-operation and at the last follow-up time (P > 0.05). CONCLUSIONS: Patients with peripheral PCE do not develop known late complications. Moreover, polymethylmethacrylate can remain stable and inert in the pulmonary vasculature over the long term. Routine prophylactic anticoagulation may not be necessary for patients with peripheral PCE during follow-up.

Long-term efficacy and safety of bone cement-augmented pedicle screw fixation for stage III Kümmell disease.

This study aimed to evaluate the efficacy and safety of bone cement-augmented pedicle screw fixation for stage III Kümmell disease. Twenty-five patients with stage III Kümmell disease who received bone cement-augmented pedicle screw fixation at the First Affiliated Hospital of Guangzhou University of Chinese Medicine between June 2009 and December 2015 were enrolled. All patients were females with a history of osteoporosis. The vertebral Cobb angle (V-Cobb angle), the fixed segment Cobb Angle (S-Cobb angle), pelvic parameters, visual Analogue Scale (VAS) score, and Oswestry Disability Index (ODI) were assessed preoperatively, postoperatively and at the final follow-up. Complications, loosening rate, operation time, and intraoperative bleeding were recorded. The average lumbar vertebral density T-value was - 3.68 ± 0.71 SD, and the average age was 71.84 ± 5.39. The V-Cobb angle, S-Cobb angle, and Sagittal Vertical Axis (SVA) were significantly smaller postoperatively compared to the preoperative values. The VAS and ODI at 1 month after surgery were 3.60 ± 1.00 and 36.04 ± 6.12%, respectively, which were both significantly lower than before surgery (VAS: 8.56 ± 1.04, ODI: 77.80 ± 6.57%). Bone cement-augmented pedicle screw fixation is a safe and effective treatment for stage III Kümmell disease. It can effectively correct kyphosis, restore and maintain sagittal balance, and maintain spinal stability.

The Modified Ultrasound-Guided Distal-to-Proximal Carpal Tunnel Injection With Median Nerve Hydrodissection: A Retrospective Safety Review of 827 Procedures.

Objective: The aim of this report is to describe a new ultrasound guided technique for carpal tunnel injection and median nerve hydrodissection using distal to proximal approach. Methods: From 2015 to 2019, 827 consecutive injections by distal-to-proximal approach were included using coding information to check for post-procedural skin hypopigmentation, hematoma, seroma, nerve injury, or vascular injury. Results: There were no occurrences of post-procedural skin-hypopigmentation, hematoma or seroma formation, or neurovascular injury. Conclusions: The distal approach carpal tunnel injection is a safe and effective method. It may directly inject the medication into carpal tunnel to avoid skin hypopigmentation from steroid side effect with previous report method, also it may release adhesion of median nerve with surrounding soft tissue by hydrodissection. It helps median nerve compression at outlet of carpal tunnel.

Ultrasound Measurements of the First Extensor Compartment: Determining the Transection Limits for Ultra-minimally Invasive Release of De Quervain Tenosynovitis.

Background: De Quervain syndrome is the second most common compressive tendinopathy. Although the length of the first extensor compartment (FEC) has been studied previously, there is no documented reported comparison study of short-axis and long-axis sonographic measurements. The thread technique, or Guo Technique, has been applied to carpal tunnel syndrome, trigger finger, and superficial peroneal compressive neuropathy. To perform this procedure, it is critically important to accurately identify the boundaries for transection. Methods: Twenty-one fresh frozen cadaver upper extremities were examined under ultrasound to determine the length of the extensor retinaculum (ER) over the FEC. Using the sonographic landmarks, the ERs were measured in short axis and long axis over their proximal to distal margins and from the distal margins to the distal edges of the radial styloids. These sonographic measurements were then compared with gross anatomical measurements. Results: The short-axis sonographic measurement of the ER on average was 22.53 mm (95% confidence interval [CI] = 20.79-24.05 mm). The long-axis sonographic measurement of the ER on average was 15.65 mm (95% CI = 13.70-17.78 mm). The average length of the ER by gross anatomical dissection was 22.40 mm (95% CI = 21.15-23.51 mm). Conclusions: The short axis is not significantly different from the gross anatomical measurement; however, the long axis is significantly lower than the gross anatomical measurement. The results support the idea that the short axis is more accurate than the long axis.

Carnosol suppresses RANKL-induced osteoclastogenesis and attenuates titanium particles-induced osteolysis.

Osteolysis is a common medical condition characterized by excessive activity of osteoclasts and bone resorption, leading to severe poor quality of life. It is essential to identify the medications that can effectively suppress the excessive differentiation and function of osteoclasts to prevent and reduce the osteolytic conditions. It has been reported that Carnosol (Car), isolated from rosemary and salvia, has anti-inflammatory, antioxidative, and anticancer effects, but its activity on osteolysis has not been determined. In this study, we found that Car has a strong inhibitory effect on the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation dose-dependently without any observable cytotoxicity. Moreover, Car can inhibit the RANKL-induced osteoclastogenesis and resorptive function via suppressing NFATc1, which is a result of affecting MAPK, NF-κB and Ca2+ signaling pathways. Moreover, the particle-induced osteolysis mouse model confirmed that Car could be effective for the treatment of bone loss in vivo. Taken together, by suppressing the formation and function of RANKL-induced osteoclast, Car, may be a therapeutic supplementary in the prevention or the treatment of osteolysis.

Selective cement augmentation of cranial and caudal pedicle screws provides comparable stability to augmentation on all segments in the osteoporotic spine: a finite element analysis.

BACKGROUND: Cement-augmented pedicle screw instrumentation (CAPSI) has been proven to significantly increase the biomechanical stability in the osteoporotic lumbar spine. However, besides the merits, it is responsible for the inevitable cement leakage growing with more instrumented segments and volumes involved. This study aimed to compare the biomechanical performance of pedicle screws augmented on all segments with those augmented only on the cranial and caudal vertebrae selectively. METHODS: The finite element model of L3-S1 was modeled with the CT data of a healthy volunteer, the solid/fenestrated pedicle screws from micro-CT scans of physical screws, and bone cement from the CT scans of a postoperative patient with CAPSI. Three different augmented strategies for pedicle screws were taken into consideration: augmentation at each pedicle trajectory (Model A), selective augmentation at the cranial and caudal pedicle trajectories (Model B), and pedicle trajectories without augmentation (Model C). A total of six surgical models were constructed: Models A, B, and C were subdivided into double segmental fusion from L4 to S1 (Models A1, B1, and C1) and multi-segment fusion from L3 to S1 (Models A2, B2, and C2). The Range of motion (ROM), stress on the cage, and stress on the fixed segments were compared among the six models. RESULTS: The ROM at the fusion segments decreased in all instrumentation models. The ROMs of Model B and Model A are similar in each direction, while that of Model C is significantly larger. The differences in the ROMs between Model A and Model B were noted to be less than 0.1°. Compared with Models A1 and A2, the peak Von Mise stress on the cage-endplate interface and pedicle screws were slightly higher in Models B1 and B2. In contrast, the stress of Models C1 and C2 increased significantly. The compressive stress was concentrated in the screw head, the cranial and caudal screws, and rods. CONCLUSIONS: The selective augmentation of pedicle screws is capable of providing reliable stability in short-segment posterior fixation (2- or 3-level). It could be a potential optimal procedure to minimize the associated complications of CAPSI.

Biomechanical evaluation of four different posterior instrumentation techniques for single-level transforaminal lumbar interbody fusion: a finite element analysis.

This study aims to investigate the fixation strength of unilateral cortical bone trajectory screw fixation (UCBT) and UCBT with contralateral translaminar facet screw fixation (UCBT-TFS) by repeating the verification of three finite element models. Three healthy female models of the lumbosacral spine were constructed. For each of them, four transforaminal lumbar interbody fusion (TLIF) models with the following instruments were created: bilateral traditional trajectory pedicle screw fixation (TT), bilateral cortical bone trajectory screw fixation (CBT), UCBT, and UCBT-TFS. A 150-N compressive load with 10 N/m moments was applied to simulate flexion, extension, lateral bending, and axial rotation. The range of motion (ROM), the stress of the cages, and the stress of the posterior fixations were compared. TT and UCBT-TFS had a similar low ROM compared to the intact models, and CBT showed a higher ROM in lateral bending. UCBT resulted in the highest ROM under all loading conditions, especially in lateral bending (116% and 170% greater than TT in left bending and right bending). UCBT induced a significant increase in the peak stress of cages and instruments, followed by CBT and UCBT-TFS, and the lowest mean values were observed for TT. Among the four different fixation techniques, TT offered the highest fixation strength and lowest implant stress, followed by UCBT-TFS and CBT, while UCBT was the least stable and resulted in increased stress of the screws and cages. UCBT-TFS improved biomechanical stability and appeared to be a less invasive alternative in well-selected patients with single-level TLIF.

Influence of cement-augmented pedicle screws with different volumes of polymethylmethacrylate in osteoporotic lumbar vertebrae over the adjacent segments: a 3D finite element analysis.

BACKGROUND: Polymethylmethacrylate (PMMA) is commonly used for cement-augmented pedicle screw instrumentation (CAPSI) to improve the fixation stability and reduce the risk of screw loosening in the osteoporotic thoracolumbar spine. Biomechanical researches have shown that various dose of cement (1-3 ml) can be injected to enhance screw stability. To date, there have been no studies on the relationship between adjacent segment degeneration and the volume of PMMA. This study aimed to explore the influence of CAPSI with different volumes of PMMA in osteoporotic lumbar vertebrae over adjacent segments by using finite element analysis. METHODS: Seven different finite element models were reconstructed and simulated under different loading conditions, including (1) an intact model, (2) three single-level CAPSI models with different volumes of PMMA (1, 1.73, and 2.5 ml), and (3) three double-level CAPSI models with different volumes of PMMA (1, 1.73, and 2.5 ml). To improve the accuracy of the finite element analysis, the models of the injectable pedicle screw and bone cement were created by using a three-dimensional scanning machine and the CAPSI patient's CT data, respectively. The range of motion (ROM), the stress of intervertebral discs, and the stress of facet in the adjacent segment were comparatively analyzed among the different models. RESULTS: The ROMs of the different segments were compared with experimental data, with good agreement under the different load conditions (21.3°, 13.55°, 13.99°, and 6.11° in flexion, extension, bending, and rotation at L3-S1 level, respectively). Compared with the intact model, the ROM, disc stresses, and facet stress in adjacent segments were found to be higher in the six operative models. Otherwise, with a larger volume of PMMA injected, the ROM, disc stresses, and facet stress slightly increased at the adjacent segment. However, the differences were insignificant with the biggest difference less than 3.8%. CONCLUSIONS: CAPSI could increase the incidence of disk degeneration in the adjacent segment, while within a certain range, different volumes of PMMA provided an approximate impact over the adjacent segment degeneration.

Pedicle Screw Fixation in Single-Level, Double-Level, or Multilevel Posterior Lumbar Fusion for Osteoporotic Spine: A Retrospective Study with a Minimum 2-Year Follow-Up.

BACKGROUND: Pedicle screw loosening is a common postoperative complication for osteoporotic patients, and several studies have identified the important role of fusion length in internal fixation failure, but the relationship between the number of fusion segments and the potential risks remains unclear. This study aimed to investigate the rate and risk factors of screw loosening in osteoporotic patients with different levels of degenerative lumbar disease. METHODS: The total cohort of 217 patients was divided into 3 groups according to the different fusion levels: single-level (group A; 100 cases), double-level (group B; 73 cases), and multilevel group (group C; 44 cases). Patient baseline demographic characteristics and assessments with a visual analog scale (VAS) and the Oswestry Disability Index (ODI) before operation and at the last follow-up were compared among the 3 groups. RESULTS: Compared with preoperative values, VAS and ODI scores at the last follow-up were significantly improved in all 3 groups. Operative time, blood loss, length of hospital stay, screw loosening rate, fusion rate, and VAS and ODI scores at the last follow-up obviously increased with the increasing number of fusion segments (group C> group B> group A). Of note, all the screw loosening was observed in cranial and caudal vertebra. Furthermore, multivariate logistic regression analysis identified lumbosacral fixation, larger pelvic incidence (PI)-lumbar lordosis (LL) difference (PT-LL), and greater postoperative pelvic tilt (PT) as independent predictors of screw loosening. However, sex, bone mineral density, body mass index, LL, sacral slope, PI, the change in LL, and preoperative PT were not relevant to screw loosening (P > 0.05). CONCLUSIONS: Owing to the high rate of screw loosening in cranial and caudal vertebra, osteoporotic patients with double-level or multilevel pedicle screw fixation benefited less than those with single-level pedicle screw fixation. Larger PI-LL, larger PT, and lumbosacral fixation are other risk factors for screw loosening. An instrument with stronger holding strength at cranial and caudal pedicle screws is recommended for those high-risk patients.

Effect and potential risks of using multilevel cement-augmented pedicle screw fixation in osteoporotic spine with lumbar degenerative disease.

BACKGROUND: The increase of augmented level and bone cement dose are accompanied by the rising incidence of cement leakage (CL) of cement-augmented pedicle screw instrumentation (CAPSI). But the effect and potential risks of the application of CAPSI to osteoporotic lumbar degenerative disease (LDD) have not been studied in the case of multilevel fixation. This study aimed to investigate the effectiveness and potential complications of using multilevel CAPSI for patients with osteoporotic LDD. METHODS: A total of 93 patients with multilevel LDD were divided into the CAPSI group (46 subjects) and the conventional pedicle screw (CPS) group (47 subjects), including 75 cases for three levels and 18 cases for four levels. Relevant data were compared between two groups, including baseline data, clinical results, and complications. RESULTS: In the CAPSI group, a total of 336 augmented screws was placed bilaterally. The CL was observed in 116 screws (34.52%). Three cemented screws (0.89%) were found loosened during the follow-up and the overall fusion rate was 93.47%. For perioperative complications, two patients (4.35%) experienced pulmonary cement embolism (PCE), one patient augmented vertebral fracture, and three patients (6.52%) wound infection. And in the CPS group, thirty-three screws (8.46%) suffered loosening in cranial and caudal vertebra with a fusion rate of 91.49%. The operation time and hospital stay of CAPSI group were longer than the CPS group, but CAPSI group has a lower screw loosening percentage (P<0. 05). And in terms of blood loss, perioperative complications, fusion rate, and VAS and ODI scores at the follow-up times, there were no significant differences between the two groups. CONCLUSIONS: Patients with osteoporotic LDD underwent multilevel CPS fixation have a higher rate of screw loosening in the cranial and caudal vertebra. The application of cemented pedicle screws for multilevel LDD can achieve better stability and less screw loosening, but it also accompanied by longer operating time, higher incidence of CL, PCE and wound infections. Selective cement augmentation of cranial and caudal pedicle screws may be a worthy strategy to decrease the complications.

Stability Evaluation of Oblique Lumbar Interbody Fusion Constructs with Various Fixation Options: A Finite Element Analysis Based on Three-Dimensional Scanning Models.

BACKGROUND: Little is known about the biomechanical performance of various fixation constructs after oblique lumbar interbody fusion (OLIF). This study aimed to explore the stability of various fixation options for OLIF by using finite element analysis based on three-dimensional scanning models. METHODS: Six validated finite element models of the L3-L5 segment were reconstructed via computed tomography images, including (1) intact model, (2) stand-alone model with no instrument, (3) lateral rod-screw model, (4) lateral rod-screw plus contralateral translaminar facet screw (LRS-CTLFS) model, (5) unilateral pedicle screw model, and (6) bilateral pedicle screw (BPS) model. Models of the OLIF cage and pedicle screw were created with three-dimensional scanning to improve the accuracy of finite element analysis. Range of motion, stress of the cage, and stress of fixation were evaluated in the different models. RESULTS: Range of motion increased from least to greatest as follows: BPS, LRS-CTLFS, unilateral pedicle screw, lateral rod-screw, stand-alone. Differences in range of motion between BPS and LRS-CTLFS were not significant for all loading cases. Compared with the other 3 models, the stress of the cage was found to be lower in BPS and LRS-CTLFS under all loading conditions, especially in BPS. Stress exerted on the fixation was the greatest in LRS-CTLFS, and the stress experienced by the translaminar facet screw was concentrated in part of the facet joint. CONCLUSIONS: The BPS model provided the best biomechanical stability for OLIF; the stand-alone model could not provide sufficient stability. The LRS-CTLFS procedure increases the approximate stability and reduces stress at the cage-endplate interface; however, it causes an increase in screw stress.

Risk Factor Analysis of the Incidence of Subsequent Adjacent Vertebral Fracture After Lumbar Spinal Fusion Surgery with Instrumentation.

OBJECTIVE: This study aimed to evaluate the risk factors for adjacent vertebral compression fractures after lumbar spinal fusion with instrumentation. METHODS: A total of 669 patients who received lumbar instrumented spinal fusion between January 2012 and December 2015 were divided into 2 groups according to whether the adjacent vertebral body was fractured. The covariates recorded were age, sex, bone mineral density, and the number of fixed segments. The anatomic variables were pelvic incidence angle (PI), preoperative lumbar lordosis angle (Pre-LL), postoperative lumbar lordosis angle (Post-LL), Pre-LL minus Post-LL (Loss of LL), postoperative pelvic tilt (Post-PT), postoperative sacral slope, Pre-PI-LL mismatch (Pre-PI minus Pre-LL), and Post-PI-LL mismatch (Post-PI minus Post-LL). A 1-way analysis of variance (ANOVA) was performed with the aforementioned parameters, and binary logistic regression analysis was used to determine the relative risk factors. RESULTS: The 669 patients were followed-up for a mean of 2.7 ± 1.1 years (range, 2-4 years). Twenty-seven patients demonstrated fractures in the adjacent vertebral body after surgery. Analysis by 1-way ANOVA demonstrated that age, PI, Pre-LL, Post-LL, Loss of LL, Post-PI-LL mismatch, Post-PT, and osteoporosis were potential risk factors (all parameters, P < 0.001). Furthermore, binary logistic regression analysis showed that a large Loss of LL, osteoporosis, and old age were also risk factors for adjacent vertebral compression fractures. CONCLUSIONS: A greater Loss of LL, osteoporosis, and advanced age may be risk factors for fractures in the adjacent vertebral body of the fixed segment after lumbar fusion fixation.

Novel Surgical Strategy for Treating Osteoporotic Vertebral Fractures with Cord Compression.

OBJECTIVES: Treatment for osteoporotic vertebral fracture (OVF) with cord compression is challenging and it usually requires surgical interventions to decompress nerves and restore spinal sequences. To describe a novel surgical strategy for treating OVFs with cord compression. METHODS: This is a single-center retrospective analysis. The inclusion criteria were Frankel grade C-E, single level T10 -L2 . Between January 2008 and December 2016, a total of 56 OVF patients (47 females and nine males, with an average age of 72 years (66-88 years), comprising of eight grade C, 23 grade D, and 25 grade E patients) were enrolled. The treatment algorithm included preoperative evaluation by MRI, extension CT, and radiography to classify the OVFs as type 1.1 (reducible, stable; n = 13), type1.2 (reducible, unstable; n = 16), type 2 (irreducible; n = 19) or type 2M (modifier; n = 8). Vertebroplasty (VP)/kyphoplasty (KP) was applied in type 1.1. VP/KP with posterior fixation and posterolateral fusion was applied in type 1.2. And additional laminectomy/osteotomy was used in type 2, except in a modifier group (2M) where same procedure as applied for type 1.2 was used. VAS, ODI, Cobb angle, Frankel functional grade, and complications were recorded. RESULTS: Thirteen cases were classified as type 1.1, 16 cases as type 1.2, 19 cases as type 2, and eight cases as type 2M. The follow-up period was 38.9 months (range, 24-108 months). All patients were followed-up in at least 24 months, in which time four patients died, two patients were lost at the last follow-up, and 50 patients completed the full study. The total VAS and ODI improved from 8 (7, 9) and 75.5% (67.2%, 80.0%) preoperatively to 2 (1, 3) and 31% (24.0%, 37.0%) on conclusion, respectively (P < 0.01). The local kyphotic angle was corrected from 22.3° (17.1°, 33. 8°) preoperatively to 10.4° (6.4°, 15.3°) on conclusion (P < 0.01). Twenty-three patients had achieved neurological recovery on conclusion (42E, 8D, P < 0.01). Asymptotic cement leakage was observed in 17/56 cases (30.4%), 6/56 in the affected vertebra (10.7%), and 24/330 in the screw trajectory (7.3%). At 2 years postoperatively, 11 new VFs had occurred in nine patients (16.1%), including VFs in nine adjacent segments that all occurred within 1 year after surgery. No cement migration or implant failure was noted. CONCLUSION: The novel surgical strategy for treating OVFs with cord compression consists of the most tailored and least invasive treatment for each patient. The positive mid- and long-term clinical and radiological outcomes observed could represent a step forward in devising the proposed algorithm.

Thread common peroneal nerve release-a cadaveric validation study.

OBJECTIVE: To determine if the thread release technique can be applied to common peroneal nerve entrapment at the fibular neck. METHODS: The thread common peroneal nerve release was performed on 15 fresh frozen cadaveric lower extremity specimens. All procedures were performed under ultrasound guidance and immediately underwent post-procedural gross anatomic inspection for completeness of decompression and presence or absence of iatrogenic neurovascular injury. RESULTS: All 15 specimens demonstrated complete transection of the deep fascia of the peroneus longus overlying the common peroneal nerve. The transections extended to the bifurcation of the superficial peroneal and deep peroneal nerves. There was no evidence of any iatrogenic damage to the neurovascular bundle or adjacent tendons. The average operating time was less than 30 min. CONCLUSION: This cadaveric validation study demonstrates the accuracy of the thread common peroneal nerve release. Future pilot studies are warranted to ensure the safety of this procedure in the clinical setting.

Augmented pedicle trajectory applied on the osteoporotic spine with lumbar degenerative disease: mid-term outcome.

PURPOSE: To compare the safety and efficiency of cement-augmented pedicle screw with traditional pedicle screw technique applied on the patients in the osteoporotic spine with lumbar degenerative diseases. METHODS: Fifty-six patients followed up at least 2 years were enrolled in our institute with retrospectively reviewed from January 2009 to June 2014, diagnosed as lumbar spondylolisthesis, or lumbar stenosis, with T score ≤- 2.5 SD of BMD, and received less than three-segment PLIF or TLIF. All patients were divided into 2 groups: 28 (2 males, 26 females) in polymethylmethacrylate-augmented pedicle screw group (PSA) group, the other 28 (3 males, 25 females) in traditional pedicle screw group (TPS). Surgical data including the operation time, intra-operative blood loss, hospitalization day and surgical complications were recorded, as well as the radiological parameters measured from the postoperative X-rays and CT scans containing the rates of fusion, screw loosening, and cage subsidence incidence. In addition, the visual analog scores (VAS) and Oswestry Disability Index (ODI) were evaluated preoperatively and postoperatively. RESULTS: The average follow-up period was 34.32 months (ranging from 24 months to 51 months). Compared with PSA group, operation time and average hospital stay in the TPS group decreased significantly (P < 0.05). While no statistical difference for blood loss between 2 groups (P > 0.05). At 2 years postoperation, from CT-scans, 2/172 screws loosening and 1/56 segment non-union occurred in PSA group, with significantly lower incidence than those in TPS group (8/152 screws loosening and 6/50 segments non-union occurred, P < 0.05). Regarding the cage subsidence, 24 segments found height loss (5.30 ± 1.92 mm) in PSA group without difference compared with that of 19 segments (4.78 ± 1.37 mm) in TPS group (P > 0.05). Besides, the number and the location of cages and the leakage of the cement were found out little related with the subsidence in the PSA group (P > 0.05). After surgeries, VAS and ODI at 1 month, 6 months, 12 months, and last follow-up improved significantly in two groups (P < 0.05). There were no significant differences in VAS and ODI preoperatively and postoperatively between 2 groups (P > 0.05). In addition, eight patients with asymptomatic trajectory PMMA leakages were detected. CONCLUSION: Cement-augmented pedicle screw technique is effective and safe in the osteoporotic spine with lumbar degenerative diseases, with better fusion rates and less screw loosening incidence. There is no difference in the fusion rate and loosening rate between the two groups in the single segment patients; however, there are better fusion rate and lower pedicle screw loosening rate of the PSA group in the double or multiple group patients.

Percutaneous cubital tunnel release with a dissection thread: a cadaveric study.

This cadaveric study tested the feasibility of decompressing the ulnar nerve across the elbow percutaneously with a commercially available surgical dissection thread, a guiding needle, hydrodissection and ultrasound guidance. We performed the procedure in 19 fresh-frozen cadaveric upper extremities. Subsequently, we did an anatomical dissection of the specimens to visualize the extent of ulnar nerve decompression and the extent of damage to surrounding structures. The cubital tunnel and deep across the medial elbow were completely transected leaving the ulnar nerve fully decompressed in all cases. There was no evidence of direct injury to the ulnar nerve or adjacent neurovascular structures. A prerequisite knowledge of sonographic anatomy and experience with interventional ultrasound is essential. Future clinical studies should evaluate this technique's safety and efficacy compared with conventional ones.

A cadaveric study using the ultra-minimally invasive thread transection technique to decompress the superficial peroneal nerve in the lower leg.

BACKGROUND: After successful applications of the ultra-minimally invasive thread transecting technique (Guo Technique) for both thread carpal tunnel release and thread trigger finger release, we hypothesized that this technique could be used for superficial peroneal nerve release in the lower leg by selective crural fasciectomy. This study is aimed at testing the operative feasibility of performing the thread superficial peroneal nerve release (TSPNR) procedure in cadavers. METHODS: The TSPNR procedure was performed on 15 fresh frozen cadaveric lower-extremity specimens under ultrasound guidance. All cadaveric specimens were dissected and visually assessed immediately after the procedures. RESULTS: All 15 legs demonstrated a complete transection of the crural fasciae along the course of the superficial peroneal nerve (SPN) including where it penetrated and traversed the crural fascia. There was no evidence of any iatrogenic damage to the neurovascular bundle or adjacent tendons. The average operating time was less than 20 min. CONCLUSION: This cadaveric study demonstrated that the technique of TSPNR was accurate, reliable, and feasible while causing no injury to adjacent neurovascular structures and avoiding having to make a skin incision. Further studies are warranted to verify the results of this study before implementing this new technique in the clinical setting.

The cement leakage in cement-augmented pedicle screw instrumentation in degenerative lumbosacral diseases: a retrospective analysis of 202 cases and 950 augmented pedicle screws.

PURPOSE: To evaluate the incidence, type and risk factors of cement leakage (CL) with cement-augmented pedicle screw instrumentation (CAPSI) in degenerative lumbosacral disease. METHODS: Two hundred and two patients using a total of 950 cement-augmented screws were enrolled. CL was classified into three types: type S: leakage via segmental veins; type B: leakage via basivertebral veins; and type I: leakage via pedicle screw instrumentation to paravertebral soft tissue. The age, gender, operation stage (primary or later stage), body mass index, bone mineral density, the number and type of augmented screw, the position of the tip of screw (lateral or internal part of vertebral body), the position of screw (left or right side), the volume of bone cement, location of the augmented vertebra (lumbar or sacrum), the type of CL and complications were recorded. Binary logistic regression correlation was used to analyze risk factors of veins leakage (type S and type B). RESULTS: The CL was observed in 165 patients (81.68%) and 335 screws (35.26%), leakage types of S, B and I were seen in 255 (76.12%), 77 (22.99%), and 30 (8.96%) of screws, respectively. Besides, double or multiple routes of leakage were seen in 27 screws. Number of augmented screw was a risk factor for vein leakage (OR 0.58; 95% CI 0.44-0.77; P = 0.000). Furthermore, the doses of cement (OR 0.79; 95% CI 0.61-0.99; P = 0.038) and the position of screw (OR 0.39; 95% CI 0.29-0.53; P = 0.000) were identified as risk factors for type S, and the doses of bone cement (OR 0.37; 95% CI 0.25-0.54; P = 0.000) and the position of the tip of screw (OR 0.07; 95% CI 0.04-0.13; P = 0.000) were risk factors for type B. CONCLUSIONS: CAPSI bears a high risk of asymptomatic CL, with a higher rate of leakage into segmental veins and basivertebral veins. As is known, more augmented screws and larger doses of cement are risk factors for veins leakage (type S and type B), while the tip of screw approaching to the midline of the vertebral body is another risk factor to type B. Thus, the CL could be reduced by the amelioration of operative techniques and procedures. These slides can be retrieved under Electronic Supplementary Material.