Journal of spine surgery最新文献

Background: Surgical intervention for scoliosis often involves extensive spinal fusions, at times spanning from the cervical spine to the pelvis. Proximal junctional failure is a known complication of C2-pelvis fusions, frequently presenting as fractures of the odontoid process. Managing these fractures is complex due to anatomical constraints and the need for structural stability while minimizing risks. This report presents a nuanced solution for a C2 fracture involving all three columns and C1 displacement in a patient with previous anterior C3-C6 and posterior C2-pelvis fusions.

Case description: A 66-year-old male with extensive spinal fusion history presented with bilateral hand paresthesia, global extremity weakness, and neck pain following a fall. Imaging revealed a comminuted type II odontoid fracture with C2 ventral body and right lateral mass involvement, along with significant spondylolisthesis of C2 secondary to ligamentous injury. Surgery was indicated due to spinal instability. Intraoperative reduction was followed by a new occiput-C7 posterior arthrodesis, including pedicle screws at C6 and C7 with a quad rod construct. C6 and C7 were not instrumented previously, or their instrumentation had been removed at some point during one of the several revisions that the patient underwent. The new rods were purposefully kept longer to connect the occipital plate to the C6 and C7 pedicle screws and then to the original C2-pelvis fusion at upper thoracic levels using side-to-side connectors. This conferred more stability to the new construct.

Conclusions: This case highlights a surgical strategy for stabilizing complex cervical fractures in patients with previous extensive fusions and limited options for fixation while allowing minimal disruption of previous fusion masses and preexisting hardware. By extending the fusion to the occiput, using cervical pedicle screws, and integrating existing hardware, we achieved sound structural stability. This approach offers a potential fusion strategy for similar cases where preserving fusion integrity and spinal stability is critical amidst challenging anatomical constraints.

Background: Pseudoarthrosis is the most common indication for revision in spinal deformity surgery. Parkinson's disease (PD) is associated with postural instability and sagittal and coronal plane deformities. Spinal fusion in PD has a high rate of complications. The risk factors for pseudoarthrosis in PD cases are yet to be elucidated. This study identifies operative and patient factors associated with pseudoarthrosis after thoracolumbar (TL) fusion in patients with PD.

Methods: In this retrospective case-control study, adult PD patients who underwent posterior TL fusion at an academic center between 2017 and 2022 were retrospectively identified. Comorbidities, functional status, PD metrics, bone and muscle quality, indications, and construct-related factors were extracted. Fusion status was assessed via continuous osseous bridging on 1-year postoperative computer-aided tomography (CT) scan. Univariate analysis compared preoperative and intraoperative variables based on fusion status.

Results: Fifty-nine patients were analyzed (27% pseudoarthrosis rate). Pseudoarthrosis was associated with screw loosening (53% vs. 16%, P=0.01) and mortality (90-day: 13% P=0.05; 1-year: 31% P=0.001). Tremor (87% vs. 54%, P=0.049), lower Hounsfield units (HU: 97 vs. 138, P=0.03), wheelchair use (25% vs. 5%, P=0.01), and trauma indications (38% vs. 5%, P=0.003) showed elevated risk of pseudoarthrosis. There were no differences in fusion rates based on PD duration, PD medications, psoas muscle area, non-traumatic indications (spondylolisthesis, deformity), interbody utilization, construct length, and bone morphogenic protein usage (P>0.05).

Conclusions: PD remains a major risk factor for poor outcomes after TL spinal fusion. Wheelchair use, lower HU, essential tremor, and trauma patients increased pseudoarthrosis rate. Pseudoarthrosis was associated with increased mortality.

Background and objective: Orthobiologics play a critical role in contemporary spine surgery. While autologous bone graft remains the gold standard for spinal fusion, its use is limited by donor site pain and morbidity, finite graft volume, and reduced osteoinductive capacity in the mineralized state. A range of orthobiologic materials has been developed to address these limitations. The objective of this narrative review is to summarize the orthobiologic options currently used in spine surgery and outline their key features, advantages, and limitations.

Methods: A nonsystematic review of the literature was performed using electronic databases to identify peer-reviewed articles relevant to the use of orthobiologics in spine surgery. Articles were reviewed in full by the authors. Orthobiologic materials were categorized, and their principal benefits and drawbacks were synthesized for inclusion in this review.

Key content and findings: Allografts, including demineralized bone matrix (DBM), provide an osteoconductive scaffold without donor site morbidity, thought heir osteoinductive capacity is variable and they lack intrinsic osteogenic potential. Growth factors, such as recombinant human bone morphogenic proteins (rhBMPs), act as potent fusion adjuvants by stimulating osteogenesis; however, concerns remain regarding their safety profile and off-label applications. Newer options, such as synthetic peptide-based compounds (e.g., P-15) and cellular-augmented allografts, represent a biomimetic approach designed to replicate natural bone matrix components and enhance fusion rates.

Conclusions: Orthobiologics are a rapidly evolving field of bone graft substitutes and extenders that can augment spinal fusion rates while minimizing the drawbacks of autologous graft harvest. Ongoing research into safety, efficacy, and cost-effectiveness will be critical to optimize their role in spine surgery.

Anterior cervical spine surgery is widely performed to manage degenerative, traumatic, and compressive spinal conditions. Despite its effectiveness, iatrogenic nerve injuries remain a significant concern due to the complex anatomy of the cervical region. This review offers a focused narrative on nerve injuries associated with anterior cervical approaches, including recurrent and superior laryngeal nerve palsy, C5 nerve root palsy, and hypoglossal nerve injury. Less common complications such as Parsonage-Turner syndrome (PTS), C8-T1 radiculopathy, and Horner's syndrome are also addressed. Each injury is discussed in terms of anatomical relevance, incidence, clinical features, diagnosis, and strategies for prevention and management. A structured review of PubMed-indexed literature from the past 25 years was conducted to ensure the inclusion of current evidence. Risk factors such as multilevel surgery, revision procedures, and excessive retraction are highlighted. While many nerve injuries are self-limited, a subset may result in long-term deficits, reinforcing the need for meticulous surgical planning and intraoperative care. By increasing awareness of these complications, this review aims to inform surgical technique and reduce morbidity in anterior cervical spine surgery. This review emphasizes not only the incidence and anatomical relevance of these complications, but also underscores the importance of preventive measures such as careful retraction, intraoperative neuromonitoring, and preoperative planning. By synthesizing data across multiple studies and including rare complications such as Horner's syndrome and PTS, this review provides a practical reference for surgeons aiming to reduce morbidity. Ultimately, the goal is to improve surgical safety and patient quality of life through heightened awareness and refinement of technique.

Background: The vertebral body plays a crucial role in supporting compressive loads and maintaining spinal biomechanics. An ideal biomaterial for total vertebral body replacement should combine biological and mechanical properties, yet no current material fulfills all criteria. This pilot study explores the use of a novel three-dimensional (3D)-printed porous polylactic acid (PLA) implant for total L1 vertebral body replacement.

Methods: This study had four stages: first, design, optimization, and 3D printing of the PLA device; second, in vitro evaluation of biocompatibility and cell growth using indirect cytotoxicity assay, direct cell viability assay, and cytochemical analysis via confocal microscopy; third, in vivo testing in 35 Wistar rats that underwent anterior retroperitoneal abdominal access for total L1 replacement with the PLA device; and finally, sequential histological analysis to assess osseointegration at 2, 4, and 6 months post-implantation. A pixel-based algorithm quantified proportions of PLA material, inflammatory and granulation tissue, fibroblastic and cartilaginous tissue, immature woven bone, and mature trabecular bone. The PLA-posterior wall interface was also examined for continuity and bone bridging.

Results: The PLA device had a parallelepiped shape with pore sizes from 150 to 500 µm, confirmed by scanning electron microscopy (SEM). In vitro tests showed no cytotoxicity and good biocompatibility, with successful growth of pre-osteoblasts on both irradiated and non-irradiated PLA. In vivo results were satisfactory, with no toxicity, a 14.29% mortality rate, and 13.33% neurological deficits. Histology showed the PLA device was mostly present at 2 months (69.55%±8.16%), with significant inflammatory tissue (22.63%±9.45%). By 4 months, woven bone (19.63%±5.81%) and fibrocartilaginous tissue (18.41%±8.87%) predominated. At 6 months, mature trabecular bone was the main tissue (43.12%±9.72%), with only 7.68%±11.24% of PLA remaining. Bone bridging at the PLA-posterior wall interface was continuous in 66.67% of rats at 6 months.

Conclusions: This pilot study shows promising in vitro and in vivo outcomes of a porous 3D-printed PLA scaffold for total L1 vertebral body replacement. Its microstructural properties, particularly porosity, supported osseointegration and bone repair. The implant presents as a strong candidate for vertebral reconstruction and may achieve enhanced results when combined with bioactive agents.

Background: The coronavirus disease 2019 (COVID-19) pandemic was an unprecedented phenomenon that affected the functioning of healthcare systems globally. At our institution (Changi General Hospital), a specialised workflow was established for emergency spinal surgeries to take place safely during the COVID-19 pandemic. This study aims to determine if time from admission to surgery for thoracic and lumbar vertebrae fractures was affected by the COVID-19 pandemic.

Methods: This was a retrospective cohort study. All patients admitted via the emergency department with thoracic or lumbar Arbeitsgemeinschaft für Osteosynthesefragen (AO) type A fractures and underwent single stage instrumentation from August 2015 to August 2022 at our institution were included in this study. The COVID-19 period was defined as the months from February 2020 to August 2022. The variables of interest included age, gender, date of admission, date of surgery and time from admission to surgery. For categorical variables, analyses were conducted using Chi-squared tests or Fisher's exact tests. After conducting a normality test using the Kolmogorov-Smirnov test, we performed Mann-Whitney U tests to compare continuous variables. A negative binomial regression model was utilised to identify factors associated with time from admission to surgery. A post-hoc power analysis was performed.

Results: From February 2020 to August 2022, 38 patients were identified. From August 2015 to January 2020, 102 patients were identified. The median number of days from admission to surgery was 6 [interquartile range (IQR), 3, 8] for the pre-COVID-19 period and 6 (IQR, 3, 9) for the COVID-19 period (P=0.38). During the COVID-19 period, more surgeries took place over the weekend (42.1% vs. 12.8%, P<0.05). The strength of this study was that all patients were managed within a single tertiary hospital with a standardised workflow. This eliminates potential variations that could compromise the validity of the results. However, this was a retrospective study of administrative data. Patients' clinical records were not assessed for factors that may potentially influence the results. This study also had a small number of patients limited to a specific condition. This limits the power to detect small but clinically relevant differences. The results also cannot be generalised to other institutions.

Conclusions: The median time from admission to surgery was not affected by the pandemic. However, there was a significant increase in the proportion of weekend surgeries being performed during the COVID-19 period.

Minimally invasive transforaminal lumbar interbody fusion (mTLIF) is an effective technique for treating degenerative lumbar spinal disorders that have failed nonoperative interventions and require fusion with or without decompression. mTLIF is technically challenging and requires significant experience with percutaneous instrumentation and microsurgical decompression techniques, which contributes to variability among surgeons and a challenging learning curve. Based on our extensive experience, we present a ten-step technique for performing mTLIF that integrates advanced technologies to enhance safety, efficiency, and reproducibility, and describe minimally invasive extraforaminal lumbar interbody fusion (mELIF), an intertransverse approach that serves as a valuable alternative-particularly in revision surgeries or cases with significant foraminal pathology-by minimizing dural exposure and reducing incidental tears. The objective is to present our experience and provide recommendations through detailed ten-step workflows for performing a total three-dimensional (3D) navigated tubular mTLIF and mELIF using expandable interbody cages and single-step navigated pedicle screws. We retrospectively reviewed our experience with mTLIF and mELIF procedures, based on a total of 350 cases, to develop step-by-step surgical techniques and workflows. These techniques were supplemented by illustrations and operative videos demonstrating the key steps. Our overview documents the key technical details for the reliable and reproducible performance of mTLIF and mELIF. Across 350 patients, complications occurred exclusively in the mTLIF cohort (2.1%), including cerebrospinal fluid (CSF) leak, wound infection, and hardware complications, with no neurological complications reported. Median hospital stay was shorter for mELIF (24 hours) compared to mTLIF (48 hours). Median follow-up time was 2.0 years. We present a comprehensive ten-step workflow for navigated mTLIF and mELIF. This workflow integrates three key features: (I) total 3D navigation, eliminating radiation exposure for the surgical team while minimizing radiation to the patient; (II) the use of expandable cages to enhance segmental lordosis; and (III) single-step navigated pedicle screws designed to streamline the surgical workflow. By providing clear and standardized workflows, we aim to support the education and training of surgeons, enabling consistent and safe outcomes.

Background: Spondylolisthesis affects a considerable portion of the population, yet high-grade spondylolisthesis (HGS) is relatively uncommon and is associated with substantial anatomical distortion, instability, and neurologic risk that complicate surgical management. Posterior transdiscal (PTD) fixation has emerged as a minimally invasive, biomechanically robust strategy that enables circumferential stabilization across the lumbosacral junction while minimizing soft-tissue disruption. The integration of robotic guidance in spine surgery may further enhance pedicle and transdiscal screw placement accuracy, streamline workflow, and improve patient safety by reducing reliance on fluoroscopy and minimizing trajectory deviations.

Case description: We conducted a retrospective case series of five consecutive patients with symptomatic HGS who underwent robotic-assisted PTD fixation at a single tertiary center. Demographic characteristics, operative variables, and perioperative events were recorded. Standardized radiographic metrics (including slip percentage and segmental alignment) and clinical outcomes were collected preoperatively and at routine postoperative intervals. Patient-reported outcomes included visual analog scale (VAS) pain scores and Oswestry Disability Index (ODI). All cases achieved successful screw placement as planned by the robotic workflow without intraoperative revisions. Statistically significant improvements were observed in VAS pain and ODI from baseline to final follow-up. Radiographs demonstrated maintenance of construct integrity and improved alignment parameters. No perioperative complications, neurologic deficits, returns to the operating room (OR), or implant-related adverse events were observed during the study period.

Conclusions: Robotic guidance in PTD fixation for HGS appears to enhance procedural accuracy and safety, facilitating reliable instrumentation in challenging anatomy while potentially reducing operative risk, radiation exposure, and complications. In this preliminary series, patients experienced meaningful reductions in pain and disability with stable radiographic outcomes and an absence of perioperative adverse events. Larger comparative studies with longer follow-up are warranted to confirm durability, quantify radiation and efficiency benefits, and define patient selection criteria for maximal benefit.

Background: Intraoperative bradycardia leading to cardiac arrest is a rare and serious complication during anterior lumbar interbody fusion (ALIF) surgeries. This case report presents a unique and previously undocumented instance of bradycardia progressing to asystole during an ALIF, highlighting the importance of autonomic nervous system involvement and intraoperative vigilance.

Case description: A 64-year-old female with a history of hypertension and morbid obesity was scheduled for an ALIF at L5/S1 due to adjacent segment disease (ASD) and foraminal stenosis at that level. Intraoperatively, after manipulation of the peritoneum and blunt dissection around the aortic bifurcation, her heart rate (HR) suddenly dropped to 50 beats per minute (bpm), followed by a rapid decrease in blood pressure (BP) and cardiac arrest. Immediate cardiopulmonary resuscitation (CPR) and administration of ephedrine successfully restored spontaneous circulation within 30 seconds. The surgical and anesthesia teams promptly decided to abort the operation. Further evaluation revealed no evidence of myocardial infarction, and the patient made a full recovery. This rare event suggests that hyper vagal stimulation from manipulation of the superior hypogastric plexus (SHP) and peritoneum may be a possible mechanism. It underscores the critical importance of vigilant monitoring, prompt intervention, and effective communication between surgical and anesthesia teams to manage acute hemodynamic instability during high-risk spinal surgeries.

Conclusions: This case illustrates a rare but critical intraoperative event likely caused by hyper vagal stimulation during anterior spinal exposure near autonomic plexuses. Surgeons and anesthesiologists must be aware of this potential complication. Prompt recognition and a coordinated team response are essential for favorable outcomes. Consideration of invasive hemodynamic monitoring and collaboration with access surgeons may improve safety in complex ALIF procedures, especially in high-risk patients such as those with morbid obesity.