International Journal of Spine Surgery最新文献

Background: Progenitor cells derived from intervertebral disc tissue demonstrated immunomodulatory and regenerative properties in preclinical studies. We report the safety and efficacy results of a US Food and Drug Administration-approved clinical trial of these cells for the treatment of symptomatic degenerative disc disease.

Methods: Sixty patients with symptomatic single-level lumbar degenerative disc disease (mean age 37.9 years, 60% men) were enrolled in a randomized, double-blinded, placebo-controlled Phase I/Phase II study at 13 clinical sites. They were randomized to receive single intradiscal injections of either low-dose cells (N = 20), high-dose cells (N = 20), vehicle alone (N = 10), or placebo (N = 10). The primary endpoint was mean visual analog scale (VAS) pain improvement >30% at 52 weeks. Disc volume was radiologically assessed. Adverse events (AEs), regardless of whether they were related to treatment, were reported. Patients were assessed at baseline and at 4, 12, 26, 52, 78, and 104 weeks posttreatment.

Results: At week 52, the high-dose group had a mean VAS percentage decrease from baseline (-62.8%, P = 0.0005), achieving the endpoint of back pain improvement >30%; the mean change was also significantly greater than the minimal clinically important difference of a 20-point decrease (-42.8, P = 0.001). This clinical improvement was maintained at week 104. The vehicle group had a smaller significant decrease in VAS (-52.8%, P = 0.044), while the low-dose and placebo groups showed nonsignificant improvements. Only the high-dose group had a significant change in disc volume, with mean increases of 249.0 mm³ (P = 0.028) at 52 weeks and 402.1 mm³ (P = 0.028) at 104 weeks. A minority of patients (18.3%) reported AEs that were severe. Overall, 6.7% of patients experienced serious AEs, all in the vehicle (n = 1) or placebo (n = 3) groups, none treatment related.

Conclusions: High-dose allogeneic disc progenitor cells produced statistically significant, clinically meaningful improvements in back pain and disc volume at 1 year following a single intradiscal injection and were safe and well tolerated. These improvements were maintained at 2 years post-injection.

Level of evidence: 1:

Clinical trial registration: NCT03347708-Study to Evaluate the Safety and Preliminary Efficacy of Injectable Disc Cell Therapy, a Treatment for Symptomatic Lumbar Intervertebral Disc Degeneration.

Background: Nowadays, minimally invasive lateral lumbar interbody fusion (LLIF) is used to treat degenerative lumbar spine disease. Many studies have proven that LLIF results in less soft tissue destruction and rapid recovery compared with open posterior lumbar interbody fusion (PLIF). Our recent cost-utility study demonstrated that LLIF was not cost-effective according to the Thai willingness-to-pay threshold, primarily due to the utilization of an expensive bone substitute: bone morphogenetic protein 2. Therefore, this study was designed to use less expensive tricalcium phosphate combined with iliac bone graft (TCP + IBG) as a bone substitute and compare cost-utility analysis and clinical outcomes of PLIF in Thailand.

Methods: All clinical and radiographic outcomes of patients who underwent single-level LLIF using TCP + IBG and PLIF were retrospectively collected. Preoperative and 2-year follow-up quality of life from EuroQol-5 Dimensions-5 Levels and health care cost were reviewed. A cost-utility analysis was conducted using a Markov model with a lifetime horizon and a societal perspective.

Results: All enrolled patients were categorized into an LLIF group (n = 30) and a PLIF group (n = 50). All radiographic results (lumbar lordosis, foraminal height, and disc height) were improved at 2 years of follow-up in both groups (P < 0.001); however, the LLIF group had a dramatic significant improvement in all radiographic parameters compared with the PLIF group (P < 0.05). The fusion rate for LLIF (83.3%) and PLIF (84%) was similar and had no statistical significance. All health-related quality of life (Oswestry Disability Index, utility, and EuroQol Visual Analog Scale) significantly improved compared with preoperative scores (P < 0.001), but there were no significant differences between the LLIF and PLIF groups (P > 0.05). The total lifetime cost of LLIF was less than that of PLIF (15,355 vs 16,500 USD). Compared with PLIF, LLIF was cost-effective according to the Thai willingness-to-pay threshold, with a net monetary benefit of 539.76 USD.

Conclusion: LLIF with TCP + IBG demonstrated excellent radiographic and comparable clinical health-related outcomes compared with PLIF. In economic evaluation, the total lifetime cost was lower in LLIF with TCP + IBG than in PLIF. Furthermore, LLIF with TCP + IBG was cost-effective compared with PLIF according to the context of Thailand.

Clinical relevance: LLIF with less expensive TCP + IBG as bone graft results in better clinical and radiographic outcomes, less lifetime cost, and cost-effectiveness compared with PLIF. This suggests that LLIF with TCP + IBG could be utilized in lower- and middle-income countries for treating patients with degenerative disc disease.

Level of evidence: 3:

Background: Various strategies have been used to reduce pedicle screw loosening following lumbar instrumented fusion, but all strategies have limitations. In this prospective multicenter cohort study, outcomes of elderly patients with reduced bone density who underwent primary or revision fusion surgery using a novel technique of pedicle screw augmentation with demineralized bone fiber (DBF) anchors were evaluated.

Methods: This study included elderly patients (aged >65 years) with dual-energy x-ray absorptiometry-confirmed reduced bone density who required lumbar pedicle screw fixation and were treated with supplemental DBF allograft anchors during primary or revision surgery. The need for DBF anchors was determined by evaluating preoperative computed tomography (CT) scans (for revision surgery) and by the surgeons' tactile feedback intraoperatively during pedicle screw insertion and removal. After determining the pedicle screw void diameter with a sizing instrument, DBF anchors and pedicle screws of the same diameter were placed into the void. CT scans were obtained on postoperative day 2 to assess pedicle breach, pedicle fracture, or anchor material extrusion and at 6 and 12 months postoperatively to assess screw loosening. Thereafter, to minimize radiation exposure, CT scans were only performed for recurrence of pain.

Results: Twenty-three patients (79% women; mean age, 74 years) received 50 lumbosacral pedicle screws augmented with DBF anchors. Most surgeries (n = 18, 78%) were revisions, and most anchors were inserted into revision pedicle screw trajectories (n = 33, 66%). Day-2 CT scans revealed no pedicle breach/fracture or extrusion of anchor material. During a mean follow-up of 15 months (12-20 months), no screw loosening was detected, and no patient required pedicle screw revision surgery. There were no adverse events attributable to DBF allografts.

Conclusions: DBF allograft anchors appear to be safe and effective for augmenting pedicle screws during revision surgeries in female elderly patients with reduced bone density.

Clinical relevance: Clinically, DBF reduced the rate of pedicle screw loosening in patients with reduced bone density. A significant reduction in screw loosening can decrease the need for revision surgeries, which are costly and carry additional risks. Enhanced bone integration from the DBF may promote better healing and long-term stability.

Level of evidence: 3:

Background: Multilevel anterior cervical discectomy and fusion inevitably yields a higher chance of pseudarthrosis or require more reoperations than single-level procedures. Therefore, multilevel cervical disc arthroplasty (CDA) could be an alternative surgery for cervical spondylosis, as it (particularly 3- and 4-level CDA) could preserve more functional motility than single-level disc diseases. This study aimed to investigate the clinical and radiological outcomes of 4-level CDA, a relatively infrequently indicated surgery.

Methods: The medical records of consecutive patients who underwent 4-level CDA were retrospectively reviewed. These highly selected patients typically had multilevel disc herniations with mild spondylosis. The inclusion criteria were symptomatic cervical spondylotic myelopathy, radiculopathy, or both, that were medically refractory. The clinical outcomes were assessed. The radiographic outcomes, including global and individual segmental range of motion (ROM) at C3-7, and any complications were also analyzed.

Results: Data from a total of 20 patients (mean age: 56 ± 8 years) with an average follow-up of 34 ± 20 months were analyzed. All patients reported improved clinical outcomes compared with that of preoperation, and the ROMs at C3-7 were not only preserved but also trended toward an increase (35 ± 8 vs 37 ± 10 degrees, pre- vs postoperation, P = 0.271) after the 4-level CDA. However, global cervical alignment remained unchanged. There was one permanent C5 radiculopathy, but no other neurological deteriorations or any reoperations occurred.

Conclusion: For these rare but unique indications, 4-level CDA yielded clinical improvement and preserved segmental motility with low rates of complications. Four-level CDA is a safe and effective surgery, maintaining the ROM in patients with primarily disc herniations and mild spondylosis.

Clinical relevance: For patients with mild spondylosis, whose degeneration at the cervical spine is not so severe, CDA is more suitable.

Level of evidence: 4:

Background: There is a lack of consensus on the use of postoperative bracing for lumbar degenerative conditions. Spine surgeons typically determine whether to apply postoperative braces based primarily on clinical experience rather than robust, evidence-based medical data. Thus, the present study sought to assess the impact of postoperative bracing on clinical outcomes, complications, and fusion rates following lumbar fusion surgery in patients with degenerative spinal conditions.

Methods: Only randomized controlled studies published between January 1990 and 20 October 2023 were included in this meta-analysis. The primary outcome measures consisted of pre- and postoperative assessments of the Oswestry Disability Index (ODI) and visual analog scale (VAS) scores. Improvements in VAS and ODI scores were analyzed in the early postoperative period (1 month after operation) and at final follow-up, respectively. The analysis also encompassed fusion rates and complications.

Results: Five studies with 362 patients were included in the present meta-analysis. In the early postoperative period, the brace group showed a relatively better improvement in ODI scores compared with the no-brace group (19.47 vs 18.18), although this difference was not statistically significant (P = 0.34). Similarly, during the late postoperative period, the brace group demonstrated a slightly greater improvement in VAS scores in comparison to the no-brace group (4.05 vs 3.84), but this difference did not reach statistical significance (P = 0.30). The complication rate was relatively lower in the brace group compared with the no-brace group (14.9% vs 17.4%), although there was no statistical difference between the 2 groups (P = 0.83). Importantly, there were no substantial differences in fusion rates between patients with or without braces.

Conclusion: The present meta-analysis revealed that the implementation of a brace following lumbar fusion surgery did not yield substantial differences in terms of postoperative pain relief, functional recovery, complication rates, or fusion rates when compared with cases where no brace was employed.

Clinical relevance: This meta-analysis provides valuable insights into the clinical impact of postoperative bracing following lumbar fusion surgery for degenerative spinal conditions.

Level of evidence: 1:

Background: Atlantoaxial transarticular fixation, also called the Magerl technique, is said to be the most robust biomechanical method of fixation of the atlantoaxial vertebrae. However, the procedure carries a risk of spinal cord and vertebral artery injury during the insertion process, especially in patients with a high-riding vertebral artery. In this study, a computed tomography (CT)-based navigation system was used for preoperative planning and insertion. This investigation sought to determine the rate and direction of screw perforation as well as the incidence of screw loosening in computer-assisted atlantoaxial transarticular fixation.

Methods: Sixty patients (31 men and 29 women; mean ± SD age: 65.3 ± 19.6 years) who received atlantoaxial transarticular screw insertion with preoperative CT navigation were analyzed. We investigated screw position and loosening by CT at the final follow-up.

Results: Of the 108 screws inserted, the rate of Grade 2 or higher perforation was 4.6% (5/108). Nine of 81 (11.1%) screws inserted into the 44 patients who were followed for at least 6 months showed loosening. Logistic regression analysis revealed that unilateral insertion (odds ratio: 8.50, 95% confidence interval: 1.53-47.2, P = 0.014) was significantly associated with the incidence of screw loosening.

Conclusions: The screw perforation rate of Grade 2 or higher in computer-assisted atlantoaxial transarticular screw fixation was 4.6%, with comparable frequencies of perforation direction. Unilateral insertion was a significant independent factor associated with screw loosening, which occurred in 11.1% of insertions.

Clinical relevance: Spine surgeons should follow up with patients with caution because screws with unilateral insertion are prone to loosening.

Level of evidence: 4:

Background: Rigid stabilization and fusion surgery are widely used for the correction of spinal sagittal and coronal imbalance (SCI). However, instrument failure, pseudoarthrosis, and adjacent segment disease are frequent complications of rigid stabilization and fusion surgery in elderly patients. In this study, we present the results of dynamic stabilization and 2-stage dynamic stabilization surgery for the treatment of spinal SCI. The advantages and disadvantages are discussed, especially as an alternative to fusion surgery.

Methods: In our study, spinal, sagittal, and coronal deformities were corrected with dynamic stabilization performed in a single session in patients with good bone quality (without osteopenia and osteoporosis), while 2-stage surgery was performed in patients with poor bone quality (first stage: percutaneous placement of screws; second stage: placement of dynamic rods and correction of spinal SCI 4-6 months after the first stage). One-stage dynamic spinal instrumentation was applied to 20 of 25 patients with spinal SCI, and 2-stage dynamic spinal instrumentation was applied to the remaining 5 patients.

Results: Spinal SCI was corrected with these stabilization systems. At 2-year follow-up, no significant loss was observed in the instrumentation system, while no significant loss of correction was observed in sagittal and coronal deformities.

Conclusion: In adult patients with spinal SCI, single or 2-stage dynamic stabilization is a viable alternative to fusion surgery due to the very low rate of instrument failure.

Clinical relevance: This study questions the use of dynamic stabilization systems for the treatment of adult degenerative deformities.

Level of evidence: 4:

Background: With the growing prevalence of lumbar spinal stenosis, endoscopic surgery, which incorporates techniques such as transforaminal, interlaminar, and unilateral biportal (UBE) endoscopy, is increasingly considered. However, the patient selection criteria are debated among spine surgeons.

Objective: This study used a polytomous Rasch analysis to evaluate the factors influencing surgeon decision-making in selecting patients for endoscopic surgical treatment of lumbar spinal stenosis.

Methods: A comprehensive survey was distributed to a representative sample of 296 spine surgeons. Questions encompassed various patient-related and clinical factors, and responses were captured on a logit scale graphically displaying person-item maps and category probability curves for each test item. Using a Rasch analysis, the data were subsequently analyzed to determine the latent traits influencing decision-making.

Results: The Rasch analysis revealed that surgeons' preferences for transforaminal, interlaminar, and UBE techniques were easily influenced by comfort level and experience with the endoscopic procedure and patient-related factors. Harder-to-agree items included technological aspects, favorable clinical outcomes, and postoperative functional recovery and rehabilitation. Descriptive statistics suggested interlaminar as the best endoscopic spinal stenosis decompression technique. However, logit person-item analysis integral to the Rasch methodology showed highest intensity for transforaminal followed by interlaminar endoscopic lumbar stenosis decompression. The UBE technique was the hardest to agree on with a disordered person-item analysis and thresholds in category probability curve plots.

Conclusion: Surgeon decision-making in selecting patients for endoscopic surgery for lumbar spinal stenosis is multifaceted. While the framework of clinical guidelines remains paramount, on-the-ground experience-based factors significantly influence surgeons' selection of patients for endoscopic lumbar spinal stenosis surgeries. The Rasch methodology allows for a more granular psychometric evaluation of surgeon decision-making and accounts better for years-long experience that may be lost in standardized clinical guideline development. This new approach to assessing spine surgeons' thought processes may improve the implementation of evidence-based protocol change dictated by technological advances was endorsed by the Interamerican Society for Minimally Invasive Spine Surgery (SICCMI), the International Society for Minimal Intervention in Spinal Surgery (ISMISS), the Mexican Spine Society (AMCICO), the Brazilian Spine Society (SBC), the Society for Minimally Invasive Spine Surgery (SMISS), the Korean Minimally Invasive Spine Society (KOMISS), and the International Society for the Advancement of Spine Surgery (ISASS).

Background: In anticipation of Food and Drug Administration (FDA) approval of the Total Posterior Spine (TOPS) system, the International Society for the Advancement of Spine Surgery (ISASS) conducted a study to estimate the work relative value units (RVUs) for facet arthroplasty. The purpose of this study was to establish a valuation of work RVU for Current Procedural Terminology (CPT) Code 0202T in the interim until the Relative Value Scale Update Committee (RUC) can determine an appropriate value. The valuation established from this survey will assist surgeons to establish appropriate procedure reimbursement from third-party payers.

Methods: A survey was created and sent to 52 surgeons who had experience implanting the TOPS system during the investigational device exemption clinical trial. The survey included a patient vignette, a description of CPT Code 0202T along with a video of the TOPS system, and a confirmation question about the illustration's effectiveness. Respondents were asked to compare the work involved in CPT Code 0202T to 8 lumbar spine procedures. A Rasch analysis was performed to estimate the relative difficulty of CPT 0202T using the work RVUs of the comparable procedures.

Results: Forty-one surgeons responded to the survey. Of all the procedures, CPT Code 0202T received the most responses for equal work compared with posterior osteotomy (46%) followed by transforaminal lumbar interbody fusion (41%). The results of the regression analysis indicate a work RVU for CPT 0202T of 39.47.

Conclusion: The study found an estimated work RVU of 39.47 for CPT Code 0202T using Rasch analysis. As an alternative to this Rasch methodology, one may consider a crosswalk methodology to the work RVUs for transforaminal lumbar interbody fusion procedurally, not as an alternative code.

Clinical relevance: These recommendations are not a substitute for RUC methodology but serve as a reference for physicians and third-party payers to understand work RVU similarities for charge and payment purposes temporarily until RUC methodology provides accurate RVUs for the procedure.

Level of evidence: 4:

Background: Intraoperative neuromonitoring (IONM) became widely used in spine surgery to reduce the risk of iatrogenic nerve injury. However, the proliferation of IONM has fallen into question based on effectiveness and costs, with a lack of evidence supporting its benefit for specific spine surgery procedures. The purpose of this study was to evaluate the use of IONM and the rate of neurological injury associated with anterior lumbar spinal surgery.

Methods: This was a retrospective study on a consecutive series of 359 patients undergoing lumbar anterior approach surgery for anterior lumbar interbody fusion (ALIF), total disc replacement (TDR), or hybrid (ALIF with TDR) for the treatment of symptomatic disc degeneration. Patients undergoing any posterior spine surgery were excluded. Operative notes were reviewed to identify any changes in IONM and the surgeon's response. Clinic notes were reviewed up to 3 months postoperatively for indications of iatrogenic nerve injury.

Results: There were 3 aberrant results with respect to IONM. Changes in IONM of a lower extremity occurred for 1 patient (0.3%). The surgeon evaluated the situation and there was no observable reason for the IONM change. Upon waking, the patient was found to have no neurological deficit. There were 2 cases of neurologic deficits in this population, which were classified as false-negatives of IONM (0.56%, 95% CI: 0.1% to 1.8%). In both cases, the patients were found to have a foot drop after the anterior approach surgery.

Conclusion: In this study, there was 1 false-positive and 2 false-negative results of IONM. These data suggest that IONM is not beneficial in this population. However, many surgeons may feel obligated to use IONM for medicolegal reasons. There is a need for future studies to delineate cases in which IONM is beneficial and the type of monitoring to use, if any, for specific spine surgery types.

Clinical relevance: This study questions the routine use of IONM in anterior lumbar approach surgery for the treatment of symptomatic disc degeneration. This has significant implications related to the cost of this practice.

Level of evidence: 4: