Journal of spine surgery最新文献

Background: There is a lack of standardization in spine surgery in particular, as relates to postoperative care for the most common spine procedures such as cervical and lumbar fusions. The goal of this study was to develop a standardized postoperative treatment protocol for common spine procedures such as cervical and lumbar fusion to reduce unnecessary visits, imaging studies, and create a standard for all spine surgeons to adhere while maintaining quality.

Methods: We developed a best practices protocol (BPP) for postoperative spine care for anterior cervical diskectomy and fusion (ACDF) and posterior lumbar interbody fusion (PLIF). We compared outcome to retrospective controls (pre-BPP) and a national database [Quality Outcomes Database (QOD)/American Spine Registry (ASR)].

Results: Pre-BPP retrospective controls (n=1,010) were compared to patients enrolled in BPP (n=750). BPP reduced postoperative visits (POV) from 2,201 to 1,061 (52%). Total additional imaging studies computed tomography (CT) and magnetic resonance imaging (MRI) beyond standard X-ray were reduced from 192 studies to 57 (70%); 53% for lumbar fusion and 67% for cervical fusion. Comparing pre-BPP to BPP groups for complications, the number of adverse events was reduced by 52% overall; 45% for lumbar fusion, and 62% for cervical fusion. A subset of BPP patients (n=450) with available data were compared to a national registry QOD and ASR where lumbar and cervical fusion patients showed comparable less lengths of stay, lower 3-month complication rates and lower readmission rates.

Conclusions: This is one of the first studies to standardize postoperative spine care as a first step towards creating uniformly accepted models for value-based care (VBC) in spine surgery.

Background: The use of plate-cage systems in anterior cervical discectomy and fusion (ACDF) has been shown to produce fusion and good clinical outcomes though it has been associated with complications such as dysphagia at higher rates than stand-alone implant devices. This study aimed to assess the incidence of dysphagia and radiographic outcomes in adult patients who have undergone ACDF with interbody spacer with integrated anchor fixation (ISa).

Methods: Patients who underwent index ACDF with a commercially available ISa by a fellowship-trained spine surgeon between January 2018 and December 2021 were retrospectively included. Patients with less than 90-days follow-up or those who underwent ACDF for trauma, infection, or tumor were excluded. Demographic data, perioperative data, radiographic data and perioperative complications were collected.

Results: Forty-five patients were included for study. Eight patients (17.8%) experienced dysphagia immediately following surgery, which resolved by 6 months post-op, barring 1 patient. Preoperative global and segmental lordosis were 10.4°±9.3° and 6.9°±7.3° respectively. At three months postoperatively, global and segmental lordosis were 8.9°±7.9° (P=0.50) and 7.0°±5.9° (P=0.56) respectively. Fusion rate at six months was 78.3% (18/23) and 100% (18/18) at 1 year.

Conclusions: ACDF with ISa is a viable alternative to traditional plate-cage systems. ISa shows lower rates of immediate, 3-month and 6-month dysphagia than traditional plate-cage systems described in the literature. More controlled studies on larger populations will help formulate a concrete conclusion on the advantages of ISa spacers.

Background: Acute kidney injury (AKI) after spinal fusion is a significant morbidity that can lead to poor post-surgical outcomes. Identifying AKI risk factors and developing a risk model can raise surgeons' awareness and allow them to take actions to mitigate the risks. The objective of the current study is to develop machine learning (ML) models to assess patient risk factors predisposing to AKI after posterior spinal instrumented fusion.

Methods: Data was collected from the IBM MarketScan Database (2009-2021) for patients >18 years old who underwent spinal fusion with posterior instrumentation (3-6 levels). AKI incidence (defined by the International Classification of Diseases codes) was recorded 90-day post-surgery. Risk factors for AKI were investigated and compared through several ML models including logistic regression, linear support vector machine (LSVM), random forest, extreme gradient boosting (XGBoost), and neural networks.

Results: Among the 141,697 patients who underwent fusion with posterior instrumentation (3-6 levels), the overall rate of 90-day AKI was 2.96%. We discovered that the logistic regression model and LSVM demonstrated the best predictions with area under the curve (AUC) values of 0.75. The most important AKI prediction features included chronic renal disease, hypertension, diabetes mellitus ± complications, older age (>50 years old), and congestive heart failure. Patients who did not have these five key risk factors had a 90-day AKI rate of 0.29%. Patients who had an increasing number of key risk factors subsequently had higher risks of postoperative AKI.

Conclusions: The analysis of the data with different ML models identified 5 key variables that are most closely associated with AKI: chronic renal disease, hypertension, diabetes mellitus ± complications, older age (>50 years old), and congestive heart failure. These variables constitute a simple risk calculator with additive odds ratio ranging from 3.38 (1 risk factor) to 91.10 (5 risk factors) over 90 days after posterior spinal fusion surgery. These findings can help surgeons risk-stratify their patients for AKI risk, and potentially guide post-operative monitoring and medical management.

Background: Cortical bone trajectory (CBT) screws can be very reliable anchors if inserted precisely anterior to the vertebral body; however, their trajectory is narrow, and malpositioning of the screw is not rare, especially for surgeons who are not familiar with the CBT screw. Patient-specific template guides are a solution to this problem; however, their accuracy and usefulness in clinical settings remain unclear. The aim of the present study was to evaluate the accuracy of long CBT placement using a patient-specific screw-guide system.

Methods: This research involved a retrospective clinical evaluation of patients who had been enrolled prospectively. One hundred consecutive patients who underwent posterior lumbar spinal fusion using the guide system performed by three experienced spine surgeons were included. Initially, the placement of the CBT screws was mapped out in three dimensions utilizing simulation software. Prior to the surgery, a specific screw guide was designed for each vertebra. Using these guides, a total of 412 screws were placed. To assess any perforation of the pedicle and to compare the discrepancies between the intended and the actual positions of the screws, postoperative computed tomography (CT) scans were utilized.

Results: Overall, 382 screws (92.7%) were fully inside the pedicle (L2-5) and there was no incidence of neurovascular injuries. The mean depth of the screw in the vertebral body (% depth) was 60.9%±8.1% and the mean % depth deviation between planned screws and actual screw was 9.6%±7.1% in total. In all vertebrae, the mean % depth was approximately 10% smaller for the actual screws than the planned screws. The mean sagittal and transverse angular deviations between the planned screws and actual screws were 2.30±1.87° and 1.89±1.26°, respectively. Overall, deviation in the sagittal angle tended to be cranial.

Conclusions: We demonstrated that a patient-specific screw guide is useful for supporting precise long CBT screw insertion into the lumbar spine in a clinical setting. This patient-specific template guide could be a potential solution to accurately insert long CBT screws and reduce complications, even for surgeons who are not experienced in the CBT technique.

The field of spinal robotics has witnessed considerable advances, which have primarily focused on enhancing pedicle screw placement. This article critically evaluates the current direction of spinal robotics development, raising concerns about the disproportionate emphasis on pedicle screw placement when existing techniques already yield commendable results. Discussions on various parameters, including quality, cost-effectiveness, and accessibility, highlight the need for a broader perspective in the development of robotics for spinal surgery. Comparative analyses reveal that navigation systems offer cost-effective and time-efficient alternatives to robotics, with similar accuracy levels. Patient demand for robotic interventions is influenced by perceived superiority, warranting careful consideration of public sentiment. This article also underscores the need for future spine surgeons to maintain proficiency in traditional techniques. The influence of industry and key opinion leaders in steering the focus toward pedicle screw placement is discussed, emphasizing the need for a more holistic approach. Accessibility issues and legal considerations in the evolving field of spinal robotics are addressed, and the potential for robotics to enhance various aspects of surgical procedures beyond pedicle screw placement is explored. In conclusion, we advocate for a shift in focus in spinal robotics, emphasizing the untapped potential to streamline common surgical procedures (such as discectomy, laminectomy, and endoscopy), enhance precision, and improve patient outcomes in areas beyond pedicle screw placement. Future advances in spinal robotics have the potential to transform the surgical landscape, benefitting all stakeholders, including patients, surgeons, and hospitals.

Background: Total joint replacement (TJR) of the lumbar spine is a revolutionary procedure that couples the clinical benefits of neural decompression with preservation of natural motion and sagittal balance at the operative level. The TJR procedure involves reconstruction of the entire motion segment using a posterior bilateral transforaminal approach to access the disc space. The TJR implant (MOTUS, 3Spine, Chattanooga, TN, USA) replaces the function of the intervertebral disc and facet joints, performing biomechanically as a new articulation for the resected, degenerated disc and facets. The implant has been optimized to simulate the kinematic characteristics of the three-joint complex.

Case description: Two male patients, ages 32 and 38 years, underwent the first TJR procedures in 2007 in South Africa. Both patients had imaging evidence of advanced spinal degeneration with unremitting back and leg pain refractory to conservative management. Symptom amelioration was achieved postoperatively with markedly reduced pains scores and improved function at clinical follow-up. Both cases were recently re-examined after 16 years and the patients reported that the procedure significantly changed their lives. Neither believes they have a lingering back condition and they have been able to fully participate in all functions related to work, family and recreation. There was little to no imaging evidence of adjacent segment disease or arthritic changes at this long-term follow-up interval.

Conclusions: After 16 years of clinical follow-up, the implant continues to function normally, without evidence of adjacent segment degeneration and both patients continue to enjoy activities of daily living without back or leg pain or other functional impairments.

Background: "Convex Pedicle Screw Technique" reduces the theoretical risk of neurovascular injury. Our aim is to evaluate the efficacy of this technique in patients with neuromuscular scoliosis (NMS).

Methods: Retrospective study of 12 patients who underwent a Convex Pedicle Screw Technique and were diagnosed with NMS. Patients who had undergone previous spinal surgery were excluded. The minimum follow-up required was 24 months. Demographic data, intraoperative data, neurovascular complications and neurophysiological events requiring implant repositioning, as well as pre- and postoperative radiological variables were collected.

Results: Twelve patients diagnosed with NMS underwent surgery. The median operative time was 217 minutes. Mean blood loss was 3.8±1.1 g/dL hemoglobin (Hb). The median postoperative stay was 8.8±4 days. A reduction of the Cobb angle in primary curve of 49.1% (from 52.8°±18° to 26.5°±12.6°; P<0.001) and in secondary curve of 25.2% (from 27.8°±18.9° to 18.3°±13.3°; P=0.10) was achieved. Coronal balance improved by 69.4% (7.5±46.2 vs. 2.3±20.9 mm; P=0.72) and sagittal balance by 75% (from -14.1±71.8 vs. -3.5±48.6 mm; P=0.50). There were no neurovascular complications. There were no intraoperative neurophysiological events requiring implant repositioning, nor during reduction maneuvers. No infections were reported.

Conclusions: The correction of the deformity from convexity in NMS achieves similar results to other techniques, and a very low complication rate.

Background: Gold standard for determining bone density as a surrogate parameter of bone quality is measurement of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA), most commonly performed on the lumbar spine (L1-L4). Computed tomography (CT) data are often available for surgical planning prior to spine procedures, but currently this information is not standardized for bone quality assessment. Besides, measuring the Hounsfield-Units (HU) is also of great importance in the context of biomechanical studies. This in vitro study aims in comparing BMD from DXA and HU based on diagnostic CT scans. In addition, methods are presented to quantify local density variations within bones.

Methods: One hundred and seventy-six vertebrae (L1-L4) from 44 body donors (age 84.0±8.7 years) were studied. DXA measurements were obtained on the complete vertebrae to determine BMD, as well as axial CT scans with a slice thickness of 1 mm. Using Mimics Innovation Suite image processing software (Materialise NV, Leuven, Belgium), two volumes (whole vertebra vs. spongious bone) were formed for each vertebra, which in turn were divided in their left and right sides. From these total of six volumes, the respective mean HU was determined. HU of the whole vertebra and just spongious HU were compared with the BMD of the corresponding vertebrae. Side specific differences were calculated as relative values.

Results: Whole bone and spongious HU correlated significantly (P>0.001; α=0.01) with BMD. A positive linear correlation was found, which was more pronounced for whole bone HU (R=0.72) than for spongious HU (R=0.62). When comparing the left and right sides within each vertebra, the HU was found to be 10% larger on average on one side compared to the opposite side. In some cases, the difference of left and right spongious bone can be up to 170%. There is a tendency for the side comparison to be larger for the spongious HU than for the whole vertebra.

Conclusions: Determination of HU from clinical CT scans is an important tool for assessing bone quality, primarily by including the cortical portion in the calculation of HU. Unlike BMD, HU can be used to distinguish precisely between individual regions. Some of the very large side-specific gradients of the HU indicate an enormous application potential for preoperative patient-specific planning.

Background: The absence of consensus for prophylaxis of venous thromboembolism (VTE) in spine surgery underscores the importance of identifying patients at risk. This study incorporated machine learning (ML) models to assess key risk factors of VTE in patients who underwent posterior spinal instrumented fusion.

Methods: Data was collected from the IBM MarketScan Database [2009-2021] for patients ≥18 years old who underwent spinal posterior instrumentation (3-6 levels), excluding traumas, malignancies, and infections. VTE incidence (deep vein thrombosis and pulmonary embolism) was recorded 90-day post-surgery. Risk factors for VTE were investigated and compared through several ML models including logistic regression, linear support vector machine (LSVM), random forest, XGBoost, and neural networks.

Results: Among the 141,697 patients who underwent spinal fusion with posterior instrumentation (3-6 levels), the overall 90-day VTE rate was 3.81%. The LSVM model demonstrated the best prediction with an area under the curve (AUC) of 0.68. The most important features for prediction of VTE included remote history of VTE, diagnosis of chronic hypercoagulability, metastatic cancer, hemiplegia, and chronic renal disease. Patients who did not have these five key risk factors had a 90-day VTE rate of 2.95%. Patients who had an increasing number of key risk factors had subsequently higher risks of postoperative VTE.

Conclusions: The analysis of the data with different ML models identified 5 key variables that are most closely associated with VTE. Using these variables, we have developed a simple risk model with additive odds ratio ranging from 2.80 (1 risk factor) to 46.92 (4 risk factors) over 90 days after posterior spinal fusion surgery. These findings can help surgeons risk-stratify their patients for VTE risk, and potentially guide subsequent chemoprophylaxis.