Spine Surgery and Related Research最新文献

Introduction: Percutaneous vertebral augmentation techniques, such as balloon kyphoplasty (BKP) and vertebral body stenting (VBS), are commonly used for surgical intervention in osteoporotic vertebral fractures (OVFs). However, markedly unstable OVF cases require additional fixation procedures, prompting the exploration of combined percutaneous vertebral augmentation and posterior fixation. A novel surgical approach involving percutaneous vertebral augmentation with upward penetrating endplate screws (PES) and downward PES, complemented by a short fusion of one above one below, was developed. This study aimed to introduce and report the preliminary outcomes of this technique based on a retrospective analysis of 20 consecutive cases in the short and medium term.

Methods: Surgical indications are a vertebral wedge angle difference of 10° or more, vertebral pedicle fractures, posterior wall fractures, and diffuse low-signal changes exceeding 50% on T1-weighted magnetic resonance imaging. The procedure is reserved for highly unstable cases following a comprehensive health assessment. The surgical technique involves prone positioning, fluoroscopy-guided percutaneous vertebral augmentation, and the use of downward PES in the cranial vertebral body and upward PES for the caudal vertebral body by percutaneous technique. The fixation range is one above and one below.

Results: The case series of 20 patients, with an average follow-up period of 146.9 days, demonstrates a mean surgical time of 57 min and minimal complications. The advantages of the technique are as follows: ease of performance, minimal fixation range, and time efficiency. Risks, such as potential screw loosening and the need for prolonged follow-up, are acknowledged.

Discussion: The technique represents a promising surgical approach that balances the requirements of minimally invasive intervention and relatively robust initial fixation for elderly osteoporotic patients with unstable OVFs. While short- and medium-term results are favorable, long-term observations are needed to further assess its efficacy. This novel technique has a potential to be a valuable surgical option for unstable OVFs.

Background: Intradiscal condoliase injection for lumbar disc herniation (LDH) was developed in Japan in 2018. The treatment is intermediate between conservative therapy and surgery, and its frequency is increasing. Condoliase is limited to a single application over a lifetime, rendering it important to understand the indications and predictors of its effectiveness. This review aimed to summarize published studies and provide appropriate indications and limitations for appropriate patient selection based on existing findings.

Methods: While adhering to PRISMA guidelines, we searched the PubMed, Web of Science, and EMBASE databases to identify articles reporting the clinical outcomes of intradiscal condoliase injection for LDH. Data extraction focused on the effective rate, prognostic factors, and posttreatment imaging changes and was used in the meta-analysis.

Results: Nineteen studies met the inclusion criteria. Our meta-analysis revealed 78% total response, 11% posttreatment surgery, and 42% posttreatment Pfirrmann-classification-grade progression rates. Posttreatment intervertebral disc degeneration was potentially associated with an improved response rate and disc regeneration one year posttreatment, especially in young patients. The Regimen for patients aged <20 and >70 years should be carefully selected, including those with a disease duration of >1 year, recurrent LDH, small-sized LDH, vertebral instability, and inadequate duration (<3 months) of conservative therapy.

Conclusions: Although long-term outcomes and imaging changes must be evaluated owing to the heterogeneity of previous studies, intradiscal condoliase injection is a minimally invasive and cost-effective treatment option for patients with LDH. Treatment indications should be determined after carefully evaluating evidence from previous conservative and surgical treatments.

Lumbar interbody fusion (LIF) is a surgical procedure for treating lumbar spinal stenosis and deformities. It removes a spinal disc and insert a cage or bone graft to promote solid fusion. Extensive research on LIF has been supported by numerous animal studies, which are being developed to enhance fusion rates and reduce the complications associated with the procedure. In particular, the anterior approach is significant in LIF research and regenerative medicine studies concerning intervertebral discs, as it utilizes the disc and the entire vertebral body. Several animal models have been used for anterior LIF (ALIF), each with distinct characteristics. However, a comprehensive review of ALIF models in different animals is currently lacking. Medium-sized and large animals, such as dogs and sheep, have been employed as ALIF models because of their suitable spine size for surgery. Conversely, small animals, such as rats, are rarely employed as ALIF models because of anatomical challenges. However, recent advancements in surgical implants and techniques have gradually allowed rats in ALIF models. Ambitious studies utilizing small animal ALIF models will soon be conducted. This review aims to review the advantages and disadvantages of various animal models, commonly used approaches, and bone fusion rate, to provide valuable insights to researchers studying the spine.

Introduction: This study aimed to measure the intraocular pressure (IOP) of patients undergoing open surgery in the supine position (control group) and spine surgery in the prone position (spine group) to clarify IOP range and change by posture, determine the risk factors for increased IOP in the prone position, and reduce visual complications after surgery in the prone position.

Methods: A prospective cohort study was conducted in healthy adults (34-83 years of age) with an American Society of Anesthesiologists classification I/II. The spine group was examined for IOP, anterior chamber angle (ACA), and fundus findings the day prior to surgery. On the day of surgery, IOP measurements were taken at fixed time points: immediately after intubation; at 0.5, 1, and 2 h after intubation; at suture closure; and at the end of surgery in the control group. In the spine group, they were taken immediately after intubation; at 0.5, 1, and 2 h after prone position; at suture closure; and immediately and 5 min after returning to the supine position. The risk factors for increased IOP in the prone position were examined.

Results: The control group showed no significant changes in IOP within the normal range (<20 mmHg) during surgery. In the spine group, IOP was higher at each time point than immediately after intubation. IOP increased sharply above the normal range within 1 h after changing from the supine to the prone position and continued to gradually increase until suture closure. IOP decreased 5 min after the patient returned to the supine position. ACA, body mass index, blood loss, time in the prone position, and operative time were not risk factors for increased IOP in the prone position.

Conclusions: Patients were constantly exposed to above-normal IOP during prone spinal surgery. However, neither group reported visual impairment. No risk factors were identified for increased IOP in the prone position.

Introduction: This study investigates the outcomes of treating neglected unstable Hangman's fractures through a single-stage Anterior Cervical Discectomy and Fusion (ACDF) procedure with tricortical iliac crest bone grafts.

Methods: Five patients with neglected unstable Hangman's fractures, treated at our institution between March 2012 and March 2017, underwent C2-C3 ACDF. Functional outcomes were assessed using the Visual Analog Scale (VAS) score and Neck Disability Index (NDI), and neurological evaluation was done using the American Spinal Injury Association (ASIA) grading system. The radiological assessment included serial plain radiographs and a computed tomography scan at a 12-month follow-up.

Results: Postoperatively, C2-C3 angulation improved significantly, decreasing from 15° to 4.4°, and sagittal translation improved from 4.2 mm to 2 mm. The VAS score improved from 6.4 to 1.4 at 24 months postsurgery. Concurrently, NDI decreased from 70.4% to 14.8%. Fusion occurred in an average of 5.6 months. Neurologically, one patient improved from ASIA grade D to grade E, while the other four retained their grade E status.

Conclusions: A single-stage ACDF with autologous iliac crest bone grafts is an effective surgical option for neglected type II/IIA Hangman's fractures, yielding satisfactory functional and radiological outcomes. This technique significantly corrects anterior translation and angulation, even in neglected cases, with the aid of intraoperative skull traction and plate reduction.

Introduction: Pedicle screws are commonly used in fixation to treat various spinal disorders. However, screw loosening is a prevalent complication, particularly in patients with osteoporosis. Various biomechanical studies have sought to address this issue, but the optimal depth and trajectory to increase the fixation strength of pedicle screws remain controversial. Therefore, a biomechanical study was conducted using finite element models.

Methods: Three-dimensional finite element models of the L3 vertebrae were developed from the preoperative computed tomography images of nine patients with osteoporosis and nine patients without who underwent spine surgery. Unicortical and bicortical pedicle screws were inserted into the center and into the anterior wall of the vertebrae, respectively, in different trajectories in the sagittal plane: straightforward, cephalad, and caudal. Subsequently, three different external loads were applied to each pedicle screw at the entry point: axial pullout, craniocaudal, and lateromedial loads. Nonlinear analysis was conducted to examine the fixation strength of the pedicle screws.

Results: Irrespective of osteoporosis, the bicortical pedicle screws had greater fixation strength than the unicortical pedicle screws in all trajectories and external loads. The fixation strength of the bicortical pedicle screws was not substantially different among the trajectories against any external loads in the nonosteoporotic vertebrae. However, the fixation strength of the bicortical pedicle screws against craniocaudal load in the cephalad trajectory was considerably greater than those in the caudal (P=0.016) and straightforward (P=0.023) trajectories in the osteoporotic vertebrae. However, this trend was not observed in pullout and lateromedial loads.

Conclusions: Our results indicate that bicortical pedicle screws should be used, regardless of whether the patient has osteoporosis or not. Furthermore, pedicle screws should be inserted in the cephalad trajectory in patients with osteoporosis.

Introduction: Despite that lateral lumbar interbody fusion (LLIF) is a minimally invasive surgery, some patients complain of severe site pain immediately after the surgery. This study aimed to explore the extent of perioperative pain after LLIF, compare the degree of perioperative pain after LLIF with that after other surgical procedures, and evaluate the factors associated with severe pain in the early postoperative period.

Methods: In this study, 93 patients who underwent lumbar spine surgeries for lumbar degenerative diseases were analyzed. The patients were categorized into three groups based on the surgical procedure: Group L, LLIF with percutaneous pedicle screw (PPS); Group P, posterolateral fusion (PLF) or posterior lumbar interbody fusion (PLIF); and Group D, posterior decompression (fenestration). The extent of low back pain was evaluated using the visual analog scale (VAS) preoperatively and from postoperative days 1 to 14.

Results: The VAS score for postoperative pain decreased in a time-dependent manner in all three groups (P<0.01). Repeated measures analysis of variance (ANOVA) showed that the VAS in Group L was significantly higher than that in Group D (P<0.01). Time point analysis revealed that the VAS scores from postoperative days 1 to 9 in Group L were significantly higher than those in Group D (P<0.05). No significant difference was observed in the VAS scores of postoperative pain between Groups L and P on all postoperative days. The VAS score for early postoperative pain in Group L was significantly correlated with the change in disc height index (P<0.05, r=0.43) and tended to be associated with the grade of preoperative disc degeneration and the VAS score of preoperative low back pain (P=0.076-0.19).

Conclusions: This study is the first to evaluate the factors associated with pain during the early postoperative period of LLIF. Although LLIF is a minimally invasive surgery, severe pain may develop in patients with significant preoperative disc degeneration or following spinal correction surgery.