Using a developed co-culture device to evaluate the proliferation of bone marrow stem cells by stimulation with platelet-rich plasma and electromagnetic field.

BACKGROUNDS: Bone marrow stem cell can differentiate to osteoblast by growth factors, pulsed low-intensity ultrasound and electric magnetic field. In the research, bone marrow stem cells were cultured; bone marrow stem cells in culture can be stimulated by platelet-rich plasma and electric field. METHODS: The culture well of the co-cultivation device has a radius of 7.5 mm and a depth of 7 mm. It is divided into two sub-chambers separated by a 3 mm high and 1 mm wide barrier. The bone marrow stem cells were seeded at a density of 2 × 104 cells and the medium volume was 120µl. Platelet-rich plasma (PRP) or platelet-poor plasma (PPP) was added to the other sub-chamber at a volume of 10µl. The bone marrow stem cells were subjected to different electric fields (0 ~ 1 V/cm) at a frequency of 70 kHz for 60 min. RESULTS: The highest osteogenic capacity of bone marrow stem cells was achieved by addition of PRP to electric field stimulation (0.25 V/cm) resulted in a proliferation rate of 599.78%. In electric field stimulation (0.75 V/cm) with PPP, the proliferation rate was only 10.46%. CONCLUSIONS: Bone marrow stem cell with PRP in the co-culture device combined with electric field at 0.25 V/cm strength significantly promoted the growth of bone marrow stem cells.

Cement augmentation for treatment of high to mid-thoracic osteoporotic compression fractures, high-viscosity cement percutaneous vertebroplasty versus balloon kyphoplasty.

Whilst the majority of the literature suggests that balloon kyphoplasty (BKP) can relieve pain associated with vertebral compression fractures (VCFs), evidence of high-viscosity cement (HVC) vertebroplasty (VP) or low viscosity cement (LVC) BKP for the treatment of VCFs at the levels of high and mid-thoracic vertebrae remains limited. The purpose of this study was to identify the different outcomes between HVC VP and LVC BKP used to repair high (T4-6) and mid (T7-9)-thoracic VCFs. A total of 114 patients with painful collapsed single-level vertebrae at high to mid-thoracic level who had undergone HVC VP or LVC BKP at a single tertiary medical center was reviewed retrospectively. All patients were divided into the HVC VP group (n = 72) and the LVC BKP group (n = 42). Clinical outcomes including demographic data and visual analogue scale (VAS) were compared. Radiographic data were collected preoperatively, postoperatively, and at final follow-up. More volume (ml) of cement injection was seen in the LVC BKP group (4.40 vs. 3.66, p < 0.001). The operation time (minutes) of the HVC VP group was significantly less than that of the LVC BKP group (33.34 vs. 39.05, p = 0.011). Leakage rate of cement was also fewer in the HVC VP group (26/72 vs. 27/42, p = 0.004). Compared with preoperative data, the VAS was improved after surgery in both groups. The LVC BKP group corrected more middle vertebral body height and local kyphosis angle than the HVC VP group. The outcomes of LVC BKP were not superior to that of HVC VP. HVC VP might be a good alternative to LVC BKP in the treatment of osteoporotic VCFs in high to mid-thoracic spine.

Percutaneous Endoscopic Interbody Debridement and Fusion (PEIDF) Decreases Risk of Sepsis and Mortality in Treating Infectious Spondylodiscitis for Patients with Poor Physical Status, a Retrospective Cohort Study.

Background: Postoperative immunosuppression is associated with blood loss and surgical trauma during surgery and subsequently predisposes patients to increased morbidity. Spine endoscopic surgery has been accepted as an effective surgical technique with less surgical trauma and less blood loss for the complication of infectious spondylodiscitis. Therefore, the aim of this study was to investigate whether PEIDF could reduce the morbidity rates for patients with infectious spondylodiscitis. Methods: We launched a retrospective cohort study on the comparison of the perioperative prognosis between PEIDF and conventional open surgery for single-level lumbar infectious spondylodiscitis in patients with poor physical health (ASA ≥ 4) from 2014 to 2019. Results: Forty-four patients were included in this study. Fifteen of them underwent PEIDF, and the rest of the 29 patients were treated with open surgery. Less surgical blood loss (p < 0.001) and intraoperative transfusions (p < 0.001) with a better decline of CRP (p = 0.017) were statistically significant in patients receiving PEIDF. Patients undergoing conventional open surgery encountered more postoperative sepsis (p = 0.030), a higher qSOFA score (p = 0.044), and prolonged-time for CRP normalization (p = 0.001). Conclusions: PEIDF minimizes a poor postoperative outcome due to less surgical trauma, intraoperative blood loss, and the need for a blood transfusion.

Proximal junctional fractures after long-segment instrumented fusion: comparisons between upper instrumented vertebrae and upper instrumented vertebrae + 1.

INTRODUCTION: Proximal junctional failure (PJF) is a well-known complication after long-segment (at least 4 vertebral levels) instrumented fusion. The etiologies of PJF include degenerative processes or are fracture induced. The fracture type of PJF includes vertebral fractures developed at the upper instrumented vertebrae (UIV) or UIV + 1. The purpose of this study was to investigate clinical and radiographic features of these two subtypes of PJF and to analyze risk factors in these patients. METHOD: In total, forty-two patients with PJF who underwent revision surgery were included. Twenty patients suffered fractures at the UIV, and the other 22 cases had fractures at UIV + 1. The weighted Charlson Comorbidity Index (CCI) and bone mineral density (BMD) T scores for these patients were recorded. Surgery-related data of index surgery and complications were collected. Radiographic parameters including pelvic tilt (PT), pelvic incidence (PI), sagittal vertical axis (SVA), lumbar lordosis (LL), and PI-LL were recorded in both groups before and after the revision surgery. RESULT: Both groups had severe osteoporosis and comorbidities. The interval between the index surgery and revision surgery was shorter in the UIV group than in the UIV + 1 group (8.2 months vs. 35.9 months; p < 0.001). The analysis for radiographic parameters in UIV and UIV + 1 group demonstrated no significant change before and after the revision surgery. However, the preoperative radiographic analysis showed a larger PT (31.5° vs. 23.2°, p = 0.013), PI (53.7° vs. 45.3°, p = 0.035), and SVA (78.6° vs. 59.4°, p = 0.024) in the UIV group compared to the UIV + 1 group. The postoperative radiographic analysis showed a larger PI-LL (27.8° vs. 18.1°, p = 0.016) in the UIV group compared to the UIV + 1 group. CONCLUSION: PJF in the UIV group tends to occur earlier than in the UIV + 1 group. Moreover, more severe global sagittal imbalances were found in the UIV group than in UIV + 1 group.

Surgery for metastatic epidural spinal cord compression in thoracic spine, anterior or posterior approach?

BACKGROUND: The most commonly encountered tumour of the spine is metastasis, and thoracic spine is the most commonly metastatic spine. Controversy exists regarding the optimal surgical approach for this kind of patient. The author conducted a study to assess the differences between anterior thoracotomy and a posterior approach in patients with malignant epidural cord compression in the thoracic spine. METHODS: Between January 2004 and December 2017, 97 patients with metastatic thoracic lesion were stratified into two groups by approach method to the lesion site: Group A - mean anterior thoracotomy, decompression and fixation; and Group P - represented posterior decompression and fixation. Survival time, neurologic status, each complication by surgery or in hospital, and days in intensive care unit(ICU) were compared. RESULTS: Twenty-five patients were grouped in Group A, and 72 patients belonged to Group P. Lung cancer was the most common primary cancer in both groups. Operation time (213.0 vs. 199.2 min, p = 0.380) and blood loss (912.5 vs. 834.4 ml, p = 0.571) were not statistically significantly different between the two groups. Six patients in Group A (24%) and 6 in Group P (8.3%) developed complications (p = 0.040). Patients in Group A required more days of care in ICUs (2.36 vs. 0.19 days, p < 0.001). The longer survival was seen in Group P (15.4 vs. 11.2 months) but with no significant difference. CONCLUSION: A lower surgical complication rate and fewer days of care in ICU were seen in Group P. The authors would prefer a posterior approach for those with thoracic metastatic tumour.

Self-assisted wound healing using piezoelectric and triboelectric nanogenerators.

The complex process of wound healing depends on the coordinated interaction between various immunological and biological systems, which can be aided by technology. This present review provides a broad overview of the medical applications of piezoelectric and triboelectric nanogenerators, focusing on their role in the development of wound healing technology. Based on the finding that the damaged epithelial layer of the wound generates an endogenous bioelectric field to regulate the wound healing process, development of technological device for providing an exogenous electric field has therefore been paid attention. Authors of this review focus on the design and application of piezoelectric and triboelectric materials to manufacture self-powered nanogenerators, and conclude with an outlook on the current challenges and future potential in meeting medical needs and commercialization.

High viscosity bone cement vertebroplasty versus low viscosity bone cement vertebroplasty in the treatment of mid-high thoracic vertebral compression fractures.

BACKGROUND CONTEXT: As science and technology have advanced, novel bone cements with numerous formulated ingredients have greatly evolved and been commercialized for vertebroplasty. Recently, viscosity has been a focus to achieve better clinical outcomes and fewer complications. Meanwhile, the experience in the treatment of mid (T7-9) to high (T4-6) thoracic vertebral compression fractures is limited. PURPOSE: The objective of this study was to identify the different outcomes between high-viscosity bone cement (HVBC) and low-viscosity bone cement (LVBC) used to repair mid (T7-9)- and high (T4-6)- thoracic vertebral compression fractures. STUDY DESIGN/SETTING: This study was a single-center, retrospective cohort study PATIENT SAMPLE: A consecutive series of 107 patients with a total of 144 vertebrae was included. OUTCOME MEASURES: The anterior vertebral height (AVH), middle vertebral height (MVH), posterior vertebral height (PVH), local kyphotic angle (KA), Cobb angle (CA), and other associated parameters were evaluated radiologically at several time points-preoperative, surgery day 0, postoperative day 1, and 6-month follow-up. Pain evaluation was assessed by using a visual analog scale (VAS) before and 6 months after the procedure. METHODS: The patients were divided into two groups according to the viscosity of the bone cement used, and plain film and magnetic resonance imaging (MRI) of the vertebrae were used to calculate parameters. The patient characteristics; bone cement brand; changes in AVH, MVH, PVH, KA, CA, and VAS; and complications of each patient were recorded and then analyzed. RESULTS: Both groups showed increased vertebral body height, corrected KA, and CA after vertebroplasty. There were no significant differences between the HVBC and LVBC groups (ΔAVH: 2.19±2.60 vs. 2.48±3.09, p=.555; ΔMVH: 1.25±3.15 vs. 1.89±2.58, p=.192; ΔKA: -5.46±4.58 vs -5.37±4.47, p=.908; and ΔCA: -4.22±4.23 vs. -4.56±5.17, p=.679). There were significant preoperative to postoperative and preoperative to follow-up changes in AVH (HVBC, p=.012 and .046, respectively; LVBC, p=.001 and .015, respectively); a significant preoperative to postoperative change in MVH (HVBC, p=.045; LVBC, p=.001); and significant preoperative to postoperative and preoperative to follow-up changes in KA and CA (KA: HVBC, p=0.000 and .003, respectively; LVBC, p=.000 and .000, respectively; CA: HVBC, p=.017 and .047, respectively; LVBC, p=.006 and .034, respectively). The volume of cement injected was significantly higher with HVBC (3.66±1.36 vs. 3.11±1.53, p=.024), and the use of HVBC was associated fewer cases with cement leakage (26 vs. 45, p=.002). Furthermore, there was no difference between the groups in the incidence of adjacent fracture. Both groups showed an improved VAS score at follow-up, with statistically greater improvement in the HVBC group (2.40±1.53 vs. 3.07±1.69, p=.014). Moreover, significantly fewer patients with a VAS score ≥ 3 were found in the HVBC group (22 vs. 39, p=.004) CONCLUSIONS: HVBC and LVBC are safe and effective to treat mid-to-high level thoracic vertebral compression fractures. Compared with LVBC, HVBC shows less cement leakage, a greater injection volume, and better postoperative pain relief.

The Influences of Spinopelvic Parameters and Associated Factors on Development of Proximal Instrumented Fracture After Posterior Instrumentation.

OBJECTIVE: To investigate influences of spinopelvic parameters, such as lumbar lordosis (LL) angles, pelvic incidence, sacral slope, pelvic tilt, and sagittal vertical axis, on development of the proximal junctional failure fracture type after posterior instrumentation. METHODS: This retrospective 1:3 matched case-control cohort study included 24 patients who developed proximal instrumented fracture in the study group and 72 patients without proximal junctional failure in the control group. Weighted Charlson Comorbidity Index and bone mineral density with T-score were recorded. In addition to spinopelvic parameters, proximal local kyphosis (PLK), which refers to a kyphosis angle between the upper end plate of upper instrumented vertebra plus 1 level and the lower end plate of upper instrumented vertebra; pelvic incidence-LL mismatch; and spinopelvic realignment score were calculated. RESULTS: More comorbidities (Charlson Comorbidity Index, P = 0.002) and poorer bone density (T-score, P = 0.001) were noted in the study group. Before surgery, the study group had significantly lower LL (P = 0.046) and sacral slope (P = 0.043) and significantly higher PLK (P < 0.001) and pelvic tilt (P = 0.044) than the control group. Postoperatively, the study group had significantly higher PLK (P < 0.001) and lower LL (P = 0.031) than the control group; the degree of pelvic incidence-LL mismatch (P = 0.007) remained significantly higher in the study group. Preoperative (P = 0.026) and postoperative (P = 0.045) spinopelvic realignment scores was worse in the study group. Multivariate analysis revealed that postoperative PLK was the most significant radiographic factor to predict proximal instrumented fracture (P = 0.002, odds ratio 1.140, 95% confidence interval). CONCLUSIONS: In our experience, appropriate LL and lower PLK should be obtained at surgery to prevent development of instrumented fracture.

Comparison of outcomes between indirect decompression of oblique lumbar interbody fusion and MIS-TLIF in one single-level lumbar spondylosis.

Minimal invasive spinal fusion has become popular in the last decade. Oblique lumbar interbody fusion (OLIF) is a relatively new surgical technique and could avoid back muscle stripping and posterior complex destruction as in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Between December 2016 and September 2018, patients with single level degenerative spondylosis were selected to enroll in this retrospective study. A total of 21 patients that underwent OLIF and 41 patients that received MIS-TLIF were enrolled. OLIF showed significantly less blood loss and shorter surgery time compared to MIS-TLIF (p < 0.05). The improvement in segmental lordosis and coronal balance was significantly more in OLIF group than MIS-TLIF group (p < 0.05). When comparing with MIS-TLIF, OLIF was significantly better in Oswestry Disability Index (ODI) and visual analogue scale for back pain improvement at post-operative 6 months (p < 0.05). Both OLIF and MIS-TLIF are becoming mainstream procedures for lumbar degenerative-related disease, especially for spondylolisthesis. However, the indirect decompression of OLIF has shown to have less perioperative blood loss and shorter surgery time than that of MIS-TLIF. In addition, OLIF gives superior outcome in restoring segmental lordosis and coronal imbalance. While both OLIF and MIS-TLIF provide optimal clinical outcomes, upon comparison between the two techniques, the indirect decompression of OLIF seems to be a superior option in modern days.

Instrumented Posterolateral fusion versus instrumented Interbody fusion for degenerative lumbar diseases in uremic patients under hemodialysis.

BACKGROUND: Advances in hemodialysis have facilitated longer lifespan and better quality of life for patients with end stage renal disease (ESRD). Symptomatic degenerative lumbar diseases (DLD) becomes more common in patients with ESRD. Posterior instrumented fusion remains popular for spinal stenosis combining instability. Only a few sporadic studies mentioned about surgical outcomes in patients with ESRD underwent spine surgeries, but no one discussed about which fusion method was optimal for this kind of patients. In this study, we compared the differences between lumbar posterolateral fusion (PLF) and lumbar interbody fusion (IBF) in uremic patients underwent instrumented lumbar surgeries. METHODS: Between January 2005 and December 2017, ESRD patients under maintenance hemodialysis underwent posterior instrumented fusion for DLD were reviewed. A PLF group and an IBF group were identified. The demographic data was collected using their medical records. Clinical outcomes were evaluated by Oswestry Disability Index (ODI) and the visual analogue scale (VAS); radiographic results were assessed using final fusion rates. Any surgical or implant-related complication was documented. RESULTS: A total of 34 patients (22 women and 12 men, mean age of 65.4 years) in PLF group and 45 patients (26 women and 19 men, mean age of 65.1 years) in IBF group were enrolled. Both groups had similar surgical levels. The operation time was longer (200.9 vs 178.3 min, p = 0.029) and the amount of blood loss was higher (780.0 vs 428.4 ml, p = 0.001) in the IBF group. The radiographic fusion rate was better in the PLF group but without significant difference (65.2% vs 58.8%, p = 0.356). Seven in the PLF group and ten in the IBF group developed surgical complications (20.5% vs. 22.2%, p = 0.788); three patients in the PLF group (8.8%) and five patients in the IBF group (11.1%) received revision surgeries because of implant-related or wound complications. Comparing to preoperative ODI and VAS, postoperative ODI and VAS obtained significant improvement in both groups. CONCLUSIONS: Successful fusion rates and clinical improvement (VAS, ODI) were similar in IBF and PLF group. Uremic patients underwent IBF for DLD had longer length of operation and higher operative blood loss than underwent PLF.

Revision Surgery for Postoperative Spondylodiscitis at Cage Level after Posterior Instrumented Fusion in the Lumbar Spine-Anterior Approach Is Not Absolutely Indicated.

Spondylodiscitis at the cage level is rare but remains a challenge for spine surgeons. In this study, the safety and efficacy of revision surgery by a posterior approach to spondylodiscitis developed at the cage level were evaluated, and these data were compared to those of patients treated with revision surgeries using the traditional anterior plus posterior approach for their infections. Twenty-eight patients with postoperative spondylodiscitis underwent revision surgeries to salvage their infections, including 15 patients in the study group (posterior only) and 13 patients in the control group (combined anterior and posterior). Staphylococcus aureus was the most common pathogen in both groups. L4-L5 was the most common infection site in both groups. The operation time (229.5 vs. 449.5 min, p < 0.001) and blood loss (427.7 vs. 1106.9 mL, p < 0.001) were the only two data points that were statistically significantly different between the two groups. In conclusion, a single posterior approach with ipsilateral or contralateral transforaminal lumbar interbody debridement and fusion plus extending instrumentation was safe and effective for spondylodiscitis developed at the cage level. This strategy can decrease the operation time and blood loss.

Impact of Osteoporosis on Different Type of Short-Segment Posterior Instrumentation for Thoracolumbar Burst Fracture-A Finite Element Analysis.

OBJECTIVE: In Taiwan (my country), the proportion of people 65 years or older was over 14% in 2018, which is known as entering "aged society." More and more thoracolumbar burst fractures in the setting of osteoporosis happen nowadays. In this study, a finite element model on thoracolumbar burst fracture was established and 4 types of posterior short-segment fixations were tested under normal bone quality and osteoporotic conditions. METHODS: The intact T11-L1 spine finite element model was created, and one-half of the spongy bone of the T12 vertebra was removed to simulate burst fracture. Four fixation models with posterior fusion devices were established: 1) a link (S-L); 2) intermediate bilateral screws (S-I); 3) a link and calcium sulfate cement (S-L-C); and 4) intermediate bilateral screws and calcium sulfate cement (S-I-C). The Young modulus of the osteoporotic cancellous bone was set at 70 MPa. Range of motion, as well as the maximum value and distribution of the implant stress on T11 and L1, were compared between normal bone and osteoporotic status. RESULTS: The strongest construct was the S-I-C group of both normal bone and osteoporosis condition. In osteoporotic status, the range of motion of construct in 4 types would be increased when comparing with normal bone. The stress on pedicle screws at the T11 and L1 level would also be increased in osteoporosis. The value of the maximal von Mises stress on the superior vertebral body (T11) for all loading conditions was larger than that on the inferior vertebral body (L1) in both normal bone and osteoporosis. CONCLUSIONS: The S-I-C provided the strongest construct even in osteoporosis status. But osteoporosis would result in weakness for spinal construct, which might lead to implant failure.

Surgical outcomes in thoracolumbar fractures with pure conus medullaris syndrome.

BACKGROUND: Pure conus medullaris syndrome is defined as a combination of signs and symptoms of bladder/bowel incontinence and impotence without the presence of lower limbs weakness. The purpose of the study is to assess the recovery of voiding, sexual, and sensory function in patients with isolated conus medullaris syndrome after surgical treatments. METHODS: From January 2005 to December 2012, patients with a single level burst fracture with pure conus medullaris syndrome were assessed. Level of injury, use of steroid, surgical time, surgical approach, preoperative radiographic parameters, and types of neurogenic bladder were recorded. Bladder function was evaluated using urodynamic study; sexual function was assessed by self-report questionnaire. The final outcomes were focused on the recovery of voiding, sexual, and sensory function. RESULTS: Eight patients met the criteria of pure conus medullaris syndrome with thoracolumbar burst fracture. The injury level were all located at L1 vertebra. There were 6 males and 2 females. Four patients had overactive neurogenic bladder, and the other 4 patients had underactive type. At final, five patients regained self-voiding function, and three required intermittent catheterization. Two male patients were sexually active, and four male patients had some sexual dysfunction. Two female patients could have normal sexual intercourse but the frequency decreased. One female patients had prolonged perineum numbness at final follow-up. CONCLUSIONS: Although extremely rare, pure conus medullaris syndrome may occur with L1 burst fracture. Despite surgical treatment, only one half of the patients regained normal bladder and sexual function.

Tuberculous spondylitis after percutaneous vertebroplasty: A case series of 9 cases.

BACKGROUND: Percutaneous vertebroplasty has become the treatment of choice for compression fractures. Although the incidence is low, infection after vertebroplasty is a serious complication. The pathogens most often responsible for infection are bacteria. Meanwhile, mycobacterium tuberculosis-induced infection is extremely rare. In this study, we reported our treatment experience with 9 cases of tuberculous spondylitis after vertebroplasty. METHODS: Between January 2001 and December 2015, 5749 patients underwent vertebroplasty or kyphoplasty in our department. Nine cases developed tuberculous spondylitis after vertebroplasty (0.16%). Data on clinical history, laboratory examinations, image, treatment and outcomes were examined. RESULTS: One male and 8 female patients with a mean age of 75.1 years developed tuberculous spondylitis after vertebroplasty. 5 patients had a history of pulmonary tuberculosis (TB). Revision surgeries were performed from 5 days to 1124 days after vertebroplasty. Seven patients underwent anterior debridement and fusion with or without posterior instrumentation, and 2 cases received posterior decompression and instrumentation only. After operation, the diagnosis of tuberculous spondylitis was confirmed by TB polymerase chain reaction (TB-PCR) or mycobacteria culture. Mean follow-up period after revision surgery was 36.8 months. At the end of follow-up, 1 patient with paraplegia had passed away, 2 needed a wheel chair, 4 required a walker and 2 were able to walk unassisted. CONCLUSIONS: Vertebroplasty is a minimally invasive procedure but still retains some possibility of complications, including TB infection. Patients with a history of pulmonary TB or any elevation of infection parameters should be reviewed carefully to avoid infective complications.

The fate of thoracolumbar surgeries in patients with Parkinson's disease, and analysis of risk factors for revision surgeries.

BACKGROUND: Compared to patients without Parkinson's disease (PD), patients with PD who underwent spinal surgeries were reported to have a relatively high complication rate. However, studies that analyze surgical risk factors for these patients are limited. METHODS: From October 2004 to April 2015, patients with PD who underwent spinal surgeries at our department were reviewed. Patients who underwent lumbar or thoracolumbar instrumented surgeries due to degeneration or deformity disease were included. Any reason for revision surgery was recorded. Risk factors including patients' factors, surgical factors, and lumbo-pelvic radiographic parameters were analyzed. Patients' factors included patients' underlying diseases, body mass index (BMI), osteoporotic status, and PD's severity using the modified Hoehn and Yahr staging scale. Surgical factors included surgical levels, extending to thoracic spine or not, corrective osteotomy, with anterior approach or not, and interbody device. Radiographic parameters included lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), coronal Cobb's angles, and score for spino-pelvic realignment achievement. RESULTS: A total of 66 patients were enrolled. The mean age at surgery was 69.0 years old. The mean follow-up time was 51.2 months. Twenty-six revision surgeries were required in 19 patients (29%). Risk factors for revision surgery included modified Hoehn and Yahr stage ≥3 (p <  0.001), cancer history (p = 0.024), osteoporosis (P = 0.012) and underwent corrective osteotomy (p = 0.035). According to binary logistic regression analysis, the modified Hoehn and Yahr stage ≥3 (p <  0.001) was the only independent risk factor. The Kaplan-Meier analysis revealed patients with long instrumentation (surgical levels > 3), T-spine instrumentation, and lower score of spino-pelvic realignment achievement tended to have earlier revision. CONCLUSION: For PD patients planning for elective thoracolumbar surgery, aggressive control status of PD before or after surgery is necessary to prevent surgical complications. Longer surgical levels and corrective osteotomy also tended to have earlier revision. A better score in spino-pelvic realignment achievement after surgery could reduce occurrence of revision.

Positive effect on spinal fusion by the combination of platelet-rich plasma and collagen-mineral scaffold using lumbar posterolateral fusion model in rats.

BACKGROUND: Platelet-rich plasma (PRP) is autologous in origin and contains a high concentration of platelets which is a source of various growth factors. Previous studies have suggested that PRP has a positive effect in accelerating fusion by an autologous bone graft in a lumbar fusion. The role of PRP on artificial bone grafts in spinal fusion remains controversial. In this study, positive effect on spinal fusion by PRP was hypothesized; in vitro and in vivo studies were designed to test this hypothesis. METHODS: PRP was produced from peripheral blood of Sprague-Dawley (SD) rats. A lumbar posterolateral arthrodesis model was used to test the efficacy of PRP on spinal fusion. Thirty SD rats were divided into three groups by different implants: the PRP group, PRP plus collagen-mineral carrier; the platelet-poor plasma (PPP) group, PPP plus collagen-mineral carrier; and the control group, collagen-mineral only. Spinal fusion was examined using plain radiographs, micro-computed tomography (micro-CT), manual palpation, and histological analysis. The fusion rate by micro-CT and that by manual palpation in groups were compared. RESULTS: In the micro-CT results, 16 fused segments were observed in the PRP group (80%, 16/20), 2 in the PPP group (10%, 2/20), and 2 in the control group (10%, 2/20). The fusion rate, determined by manual palpation, was 60% (6/10) in the PRP group, 0% (0/10) in the PPP group, and 0% (0/10) in the control group. Histology showed that the PRP group had more new bone and matured marrow formation. CONCLUSIONS: The results of this study demonstrated that PRP on an artificial bone carrier had positive effects on lumbar spinal fusion in rats. In the future, this composite could be potentially used as a bone graft in humans.

Short-Segment Instrumentation with Fractured Vertebrae Augmentation by Screws and Bone Substitute for Thoracolumbar Unstable Burst Fractures.

BACKGROUND: For thoracolumbar burst fractures, traditional four-screw (one above and one below) short-segment instrumentation is popular and has a high failure rate. Additional augmentation at the fractured vertebrae is believed to reduce surgical failure. The purpose of this study was to examine the clinical and radiographic results of patients who underwent short-segment posterior instrumentation with augmentation by screws and bone substitutes at the fractured vertebrae and to compare these data to those of patients who underwent long-segment instrumentation for thoracolumbar burst fractures. METHODS: The study group had twenty patients who underwent short-segment instrumentation with additional augmentation by two screws and bone substitutes at the fractured vertebrae. The control group contained twenty-two patients who underwent eight-screw long instrumentation without vertebra augmentation. Local kyphosis and the anterior body height of the fractured vertebrae were measured. The severity of the fractured vertebrae was evaluated with the load sharing classification (LSC). Any implant failure or loss of correction >10° at the final follow-up was defined as surgical failure. RESULTS: Both groups had similar distributions in terms of age, sex, the injured level, and the mechanism of injury before operation. During the operation, the study group had significantly less blood loss (136.0 vs. 363.6 ml, p=0.001) and required shorter operating times (146.8 vs. 157.5 minutes, p=0.112) than the control group. Immediately after surgery, the study group had better correction of the local kyphosis angle (13.4° vs. 11.9°, p=0.212) and restoration of the anterior height (34.7% vs. 31.0%, p=0.326) than the control group. At the final follow-up, no patients in the study group and only one patient in the control group experienced surgical failure. CONCLUSIONS: Patients with thoracolumbar burst fractures who received six-screw short-segment posterior fixators with augmentation at the level of the fractured vertebrae via injectable artificial bone substitute achieved satisfactory clinical and radiographic results, and this method could replace long-segment instrumentation methods used in unstable thoracolumbar burst fractures.

Surgical outcomes of infectious spondylitis after vertebroplasty, and comparisons between pyogenic and tuberculosis.

BACKGROUND: Infection after vertebroplasty (VP) is a rare but serious complication. Previous literatures showed most pathogens for infection after VP were bacteria; tuberculosis (TB) induced infection after VP was extremely rare. We reported our treatment experiences of cases with infectious spondylitis after VP, and compared the differences between developed pyogenic and TB spondylitis. METHODS: From January 2001 to December 2015, 5749 patients had undergone VP at our department were reviewed retrospectively. The causative organisms were obtained from tissue culture of revision surgery. Parameters including type of surgery, the interval between VP and revision surgery, neurologic status, and visual analog scale (VAS) of back pain were recorded. Laboratory data at the time of VP and revision surgery were collected. Charlson comorbidity index (CCI), preoperative bacteremia, urinary tract infection (UTI), pulmonary TB history were also analyzed. RESULTS: Eighteen patients were confirmed with developed infectious spondylitis after VP (0.32%, 18/5749). Two were male and 16 were female. The median age at VP was 73.4 years. Nine patients were TB and the other nine patients were pyogenic. The interval between VP and revision surgery ranged from 7 to 1140 days (mean 123.2 days). The most common type of revision surgery was anterior combined with posterior surgery. Seven patients developed neurologic deficit before revision surgery. Three patients died within 6 months after revision surgery, with a mortality of 16.7%. Finally, VAS of back pain was improved from 7.4 to 3.1. Seven patients could walk normally, the other 8 patients had some degree of disability. Both pyogenic and TB group had similar age, sex, and CCI distribution. The interval between VP and revision surgery was shorter in the patients with pyogenic organisms (75.9 vs 170.6 days). At revision surgery, WBC and CRP were prominently elevated in the pyogenic group. Five in the pyogenic group had UTI and bacteremia; five in TB group had a history of lung TB. CONCLUSIONS: Infection spondylitis after VP required major surgery for salvage with a relevant part of residual disability. Before VP, any bacteremia/UTI or history of pulmonary TB should be reviewed rigorously; any elevation of infection parameters should be scrutinized strictly.

Postoperative Infection in Patients Undergoing Posterior Lumbosacral Spinal Surgery: A Pictorial Guide for Diagnosis and Early Treatment.

Surgical site infections after posterior spinal surgery may lead to spondylodiscitis, pseudarthrosis, correction loss, adverse neurological sequelae, sepsis, and poor outcomes if not treated immediately. Infection rates vary depending on the type and extent of operative procedures, use of instrumentation, and patients' risk factors. Image evaluation is crucial for early diagnosis and should be complementary to clinical routes, laboratory survey, and treatment timing. Magnetic resonance imaging detects early inflammatory infiltration into the vertebrae and soft tissues, including hyperemic changes of edematous marrow, vertebral endplate, and abscess or phlegmon accumulation around the intervertebral disk, epidural, and paravertebral spaces. Aggressive surgical treatment can eradicate infection sources, obtain a stable wound closure, decrease morbidity, and restore spinal integrity. Organ/space infection is defined as any body parts opened to manipulate other than superficial/deep incision. Advanced magnetic resonance imaging evaluating abnormal fluid accumulation, heterogenous contrast enhancement of the endplate erosion due to cage/screw infection is categorized to inform a presumptive diagnosis for early implant salvage. However, patients' defense response, infection severity, bacteriology, treatment timing, spinal stability, and available medical and surgical options must be fully considered. Revision surgery is indicated for pseudarthrosis, implant loosening with correction loss, recalcitrant spondylodiscitis, and adjacent segment diseases for infection control.

Surgical outcomes in the elderly with degenerative spondylolisthesis: comparative study between patients over 80 years of age and under 80 years-a gender-, diagnosis-, and surgical method-matched two-cohort analyses.

BACKGROUND: In Taiwan, the current life expectancy of an 80-year-old man is 88.4 years and that of an 80-year-old is woman is 89.8 years. Surgical candidates older than 80 years usually ask surgeons whether it would be safe for them to undergo surgery. PURPOSE: The objectives of this study were to report the surgical outcomes of patients with degenerative spondylolisthesis who were older than 80 years and underwent instrumented surgeries and to compare these data with the outcomes of patients aged 65-79 years. STUDY DESIGN/SETTING: This is a retrospective study. PATIENT SAMPLE: The study included 76 patients. OUTCOME MEASURES: The preoperative medical condition was reviewed using the weighted Charlson Comorbidity Index (CCI) and the American Society of Anesthesiologists (ASA) physical status classification. Clinical outcomes were evaluated according to the Oswestry Disability Index (ODI) and the visual analog scale (VAS) for leg and back pain. Plain radiographs were used to assess the fusion status, implant-related complications, and the prevalence of osteoporotic compression fractures (OVFx). MATERIALS AND METHODS: The study comprised patients older than 80 years, and the control group comprised patients aged 65-79 years. The two cohorts were matched for gender, main diagnosis, and surgical method. RESULTS: In total, 76 patients were included in the study. The study group had 38 patients with a mean age of 82.4 years (80-93 years); the control group also had 38 patients with a mean age of 70.8 years (65-79 years). The study group had a significantly higher ASA classification (2.94 vs. 2.76, p=.040) and CCI score (1.84 vs. 1.13, p=.012). The study group had a higher prevalence of preoperative OVFx (10.5% vs. 2.6%, p=.116) and incidence of new-onset OVFx (13.2% vs. 2.6%, p=.089). The study group had longer operative times (204.6 vs. 179.1 minutes, p=.052) with more blood loss (606.5 vs. 525.8 mL, p=.512), but this finding was not statistically significant. The mean ODI and VAS scores were similar between the two groups. The bone union rate was superior in the control group (81.6% vs. 89.5%, p=.328). CONCLUSIONS: Patients older than 80 years have a higher osteoporotic status and comorbidities, which may lead to longer operative times and greater blood loss, with poorer radiographic outcomes. However, the clinical results were not affected. With appropriate patient selection, the age of >80 years is not a negative predictive factor for instrumented surgery for degenerative spondylolisthesis.