International Journal of Spine Surgery最新文献

Background: Lumbar fusion eliminates motion at the operative level and is associated with altered load transfer and adjacent segment degeneration. Total joint replacement (TJR) of the lumbar spine is a motion segment reconstruction procedure performed via a bilateral transforaminal approach that allows direct neural decompression and replacement of both disc and facet function. This prospective investigational device exemption clinical trial compared TJR with a concurrent, propensity-score-weighted real-world evidence cohort treated with either instrumented transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody spine fusion (PLIF).

Methods: This multicenter investigational device exemption trial was conducted at 20 US sites. Patient-reported outcomes from 152 TJR subjects implanted with the MOTUS device were compared with 142 propensity score-weighted TLIF/PLIF controls. Lumbar-related disability was measured with the Oswestry Disability Index (ODI) and back and worst leg pain severity by a 100-mm visual analog scale (VAS). Minimal clinically important difference thresholds were ODI ≥ 15 points and VAS ≥ 20 mm; responder analyses were also conducted using ≥30% and substantial clinical benefit (≥50%) thresholds. Effect sizes were calculated using Cohen's d or h.

Results: Baseline characteristics were well balanced, and there were no statistically significant differences between study groups. At 12 months, mean ODI decreased by 45 points (71%) with TJR and 37 points (59%) with TLIF/PLIF. The adjusted between-group difference was 8.1 points (95% CI, 2.5-13.7; P = 0.005; Cohen's d = 0.39, small). VAS back and leg pain decreases were similar between groups, with no significant between-group differences. Minimal clinically important difference responder rates were high (>85%) for both procedures; the ≥30% ODI threshold favored TJR (90% vs 80%; P = 0.04).

Conclusions: Substantial decreases in back impairment and pain severity were realized in both study groups. However, longitudinal improvement in ODI significantly favored patients treated with TJR.

Clinical relevance: Lumbar TJR combines decompression with motion preservation in a single procedure, potentially offering an alternative to fusion in selected patients. The advantage of utilizing a standard posterior operative approach with TJR is that it allows for direct decompression of the neural elements prior to implant placement.

Level of evidence: 2b.

As the population ages and the incidence of spine surgeries increases, better solutions are needed for the challenges of adequate pain control and lengthy hospital stays, which often result from difficulty with controlling pain, managing complications, or coordinating post-hospitalization care services. Thus, there is an inherent need for ways to improve pain and time to discharge. Minimally invasive techniques aim to minimize tissue disruption and can decrease pain and accelerate recovery. However, these techniques are not indicated for all spine patients, and not all spine surgeons are adequately trained in such techniques, thus limiting generalizability. In contrast, Enhanced Recovery After Surgery (ERAS) has recently been adopted within spine surgery as an alternative management strategy to optimize patient outcomes. Enhanced recovery principles mitigate the surgical stress response through a series of evidence-based, perioperative interventions that have demonstrated success with reducing postoperative pain and complications, increasing ambulation, and shortening length of stay. While still in its infancy within spine surgery, there is ample evidence for the successful implementation of ERAS programs for numerous spine procedures. However, further randomized trials will likely be needed to support the continued application of ERAS within spine surgery.

Background: Excessive stress on the pedicle screws or inadequate load-sharing with surrounding spinal components increases the mechanical demand and the risk of loosening or breakage. The lumbar interfacet cage (FFX device) is designed to prevent spinal instability and facet motion, enhancing facet joint fusion.

Objective: The present study aimed to compare the biomechanical performance of a lumbar interfacet cage when associated with a pedicle screw construct, compared with pedicle screws alone and pedicle screws associated with lumbar interbody cages, using the FE method.The authors hypothesized that implanting additional lumbar interfacet cages would reduce mechanical stress on pedicle screw constructs.

Study design: Comparative biomechanical study by finite element (FE) method.

Methods: A validated FE model for the lumbar spine was used to assess stress variations on pedicle screw constructs and discs in the prefusion stage following surgery. Modeled scenarios included (1) a short pedicle screw construct (L4/L5), with and without bilateral lumbar interfacet cage device placement and with or without interbody fusion cages, and (2) a long pedicle screw construct (L2-S1), with and without lumbar interfacet cage placement at all levels.

Results: Both facet and interbody cage placement in conjunction with short L4/L5 pedicle screw constructs significantly reduced mechanical loading on pedicle screws and rods compared with the pedicle screw construct alone. The placement of lumbar interfacet cages used in combination with pedicle screw constructs in long L2 to S1 constructs also significantly reduced stress loading on pedicle screws and rods, especially at the lower extremity of the construct.

Conclusions: The placement of facet cages in conjunction with pedicle screws can improve the load distribution of the construct, enhancing its stability and durability. This approach may help reduce the rate of pedicle screw loosening and breakage, which are complications commonly associated with long pedicle screw constructs.

Clinical relevance: Pedicle screw loosening and breakage remain frequent complications in lumbar fusion, especially in long constructs. This finite element analysis demonstrates that adding lumbar interfacet cages to pedicle screw constructs significantly reduces mechanical stress on screws and rods. By improving load distribution in both short and long constructs, the technique may decrease the risk of screw loosening and implant failure before fusion, potentially improving construct durability and reducing reoperation rates.

Level of evidence: 5:

Objective: This study aims to introduce an innovative technique for placing pedicle screws in patients with extremely small lumbar pedicles using an oblique view from a C-arm x-ray machine, achieving a comparable gripping force to conventional implanting for the treatment of thoracolumbar vertebral fractures.

Methods: A retrospective analysis was conducted on 11 patients with extremely small lumbar pedicles and thoracolumbar vertebral body fractures. The height of the vertebral body and Cobb angle were measured on computed tomography radiographs, and comparisons were made between pre- and postoperative values. Scores from the visual analog scale, Oswestry Disability Index, and Short Form-36 were recorded to evaluate the surgical outcomes.

Results: All patients successfully underwent the surgery without intraoperative complications such as pedicle collapse, cerebrospinal fluid leakage, or nerve damage. The height of the anterior margin of the vertebral body and the compression rate of the anterior margin of the injured vertebrae showed significant improvement, as did the Cobb angle, with statistically significant differences (P < 0.05). The patients' visual analog scale, Oswestry Disability Index, and Short Form-36 scores were all significantly reduced compared to preoperative levels (P < 0.05). All cases demonstrated excellent reconstruction and maintenance of spinal stability, with the longest follow-up reaching 2 years postoperatively. No issues such as screw loosening or extraction were observed during this period.

Conclusions: The C-arm x-ray machine oblique radiograph-assisted external pedicle implanting approach offers a simple, accurate, and safe alternative for internal fixation surgery in patients with extremely small lumbar pedicles, without the need for an O-arm navigation system.

Clinical relevance: This retrospective cohort study confirms that the technique is a highly effective modality for managing thoracolumbar vertebral fractures with extremely narrow lumbar pedicles, reliably restoring and maintaining spinal stability, and thus offering a novel therapeutic option for clinicians.

Background: To evaluate the clinical and radiological outcomes of biportal endoscopic lumbar interbody fusion (BE-LIF) using the 30-degree endoscope in patients with lumbar spondylolisthesis and severe disc height loss and to highlight its technical advantages in endplate preparation and contralateral decompression.

Methods: This retrospective study included 21 patients with single-level Meyerding grade II spondylolisthesis and preoperative disc height <5 mm who underwent BE-LIF combined with percutaneous pedicle screw fixation between February 2023 and February 2025. Clinical outcomes were assessed using the visual analog scale for back and leg pain and the Oswestry Disability Index. Radiographic parameters, including vertebral slip, disc height, and foraminal height, were evaluated on standing lateral x-ray images, while fusion status was assessed using Bridwell grading on 6-month postoperative computed tomography scans.

Results: At a mean follow-up of 11.7 ± 2.6 months, all patients demonstrated statistically significant clinical improvement, visual analog scale scores decreased from 7.2 ± 0.6 to 1.5 ± 0.5 for low back pain, from 7.5 ± 0.5 to 1.7 ± 0.6 for leg pain, and the Oswestry Disability Index improved from 42.6 ± 5.7 to 15.7 ± 2.5 (P < 0.001). Radiologically, vertebral slip was reduced from 11.3 ± 1.5 mm to 2.1 ± 0.4 mm. Anterior and posterior disc heights increased from 5.6 ± 0.6 mm and 4.9 ± 0.5 mm to 8.5 ± 1.2 mm and 8.3 ± 1.4 mm, respectively. Foraminal height improved from 9.8 ± 1.7 mm to 14.7 ± 2.8 mm. Fusion was confirmed in all cases (Bridwell grade I: 28.6%, grade II: 71.4%), with no cage subsidence or major complications reported.

Conclusion: The use of the 30-degree endoscope in BE-LIF for spondylolisthesis with severe disc collapse provides enhanced visualization, facilitates safe and effective decompression, and results in favorable clinical and radiological outcomes.

Level of evidence: 3:

Background: Far-out syndrome is considered a rare spinal disorder characterized by L5 radiculopathy due to extraforaminal stenosis at the lumbosacral junction. Despite advancements in surgical techniques, managing far-out syndrome remains a significant challenge owing to the complex anatomical variations usually associated with the condition. This article reports 2 cases of far-out syndrome resulting from anterolateral vertebral osteophyte formation that underwent anterior decompression. A comprehensive review of the literature is also provided.

Case presentation: A 51-year-old man and a 72-year-old woman presented with progressive leg pain and neurogenic claudication associated with hypesthesia over the left L5 dermatome. Radiological findings in both patients revealed entrapment of the L5 nerve root by anterolateral vertebral osteophytes at the anterior exit zone of the foramen. One patient presented with Castellvi Type IV lumbosacral transitional vertebra, and the other patient showed spontaneous facet joint fusion at adjacent segments.

Case management: We performed anterior-extraperitoneal osteophytectomy using an ultrasonic bone dissector to decompress the extraforaminal stenosis, which resulted in successful resolution of the symptoms and improved neurological status. Both patients remained asymptomatic at the 1-year follow-up.

Conclusions: Extraforaminal stenosis at the lumbosacral junction due to anterolateral vertebral osteophytes usually occurs in patients with anatomical abnormalities such as lumbosacral transitional vertebra and adjacent segment fusion. Anterior decompression via extraperitoneal approach is an effective and safe treatment option for far-out syndrome, offering a viable alternative to the conventional posterior approach.

Level of evidence: 5:

Background: Transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) are 2 surgical approaches for achieving arthrodesis and restoring alignment. Novel expandable interbody technology may provide an advantage for TLIF procedures. Limited comparative data exist for LLIF with static interbody cages and TLIF with expandable interbody cages. This study aimed to examine the differences in radiographic and clinical outcomes between these procedures.

Methods: This is a retrospective analysis comparing single-level LLIF with static interbody cages and TLIFs with expandable interbody cages performed at our institution. Demographic, operative, radiographic, and patient-reported data were collected. Upright radiographic images were used to assess pre- and postoperative radiographic parameters. Patient-reported outcomes were assessed using the Oswestry Disability Index and minimal clinically important difference (MCID).

Results: A total of 163 patients, 75 in the TLIF group and 88 in the LLIF group, were included in this study (mean age: 63.3 ± 12.0 years; 54.8% women). Mean follow-up was 306.2 ± 161.4 days for the TLIF group and 502.3 ± 308.0 days for the LLIF group (P = 0.021). Both groups demonstrated significant improvements in lumbar lordosis, neuroforaminal height, and disc angle (P < 0.01). LLIF patients demonstrated a significant correction of segmental lordosis (P < 0.01), whereas TLIF patients did not (P > 0.05). Patients in the LLIF group demonstrated a greater increase in segmental lordosis (P = 0.005) and neuroforaminal height (P < 0.001) in comparison to those in the TLIF group. In addition, a modest but significant advantage was observed in overall lumbar lordosis in LLIF (P = 0.049). A significantly greater proportion of patients who underwent LLIF achieved an MCID (80.6% vs 66.7%, P = 0.041). The LLIF group had significantly fewer cases of radiographic subsidence than TLIF (10.2% vs 44%, P < 0.001). TLIF was the only significant predictor of subsidence (OR = 4.630 [1.493-14.364], P < 0.001).

Conclusions: LLIF resulted in greater restoration of neuroforaminal height and segmental lordosis, as well as a modest advantage in lumbar lordosis. In addition, a significantly greater proportion of patients who underwent LLIF achieved MCID. TLIF was a significant predictor of subsidence when controlling for confounding factors.

Clinical relevance: With the advent of expandable interbodies in TLIF, our findings demonstrate suboptimal radiographic and patient-reported outcomes in comparison to LLIF with static interbody cages. Surgeons should exercise caution regarding utilizing expandable interbody technology during TLIF.

Level of evidence: 3:

Background: Minimally invasive surgical techniques have the potential to decrease the morbidity associated with traditional open surgery. However, surgeons may hesitate to implement minimally invasive techniques in their practice due to limited direct visualization and an arduous learning curve. Minimally invasive spine surgery requires precise docking of tubular or endoscopic retractors, which is difficult because without direct visualization of surrounding structures, surgeons may find themselves unable to orient themselves. Finding consistent and reproducible radiographic landmarks may decrease barriers to adoption of MISS techniques. Abd-El-Barr's point is a novel radiographic landmark that is identified on lateral fluoroscopy to help with docking for both tubular and endoscopic spine procedures. The landmark is hypothesized to correlate closely with the caudal aspect of the lamina and serve as a reliable docking target.

Objective: To validate Abd-El-Barr's point as a radiographic landmark for safe, reliable, and consistent docking in minimally invasive lumbar surgery.

Methods: A cadaveric study design: fluoroscopic localization of Abd-El-Barr's point was performed bilaterally from L1 to S1 using a sharply pointed instrument that was inserted slightly into the lamina to mark it with a hole, followed by dissection to measure the distance between the mark and the caudal lamina.

Results: A total of 5 cadaveric specimen data were analyzed. The mean distance from Abd-El-Barr's point to the caudal aspect of the lamina across all measured levels and sides was 5.3 mm (bilaterally).

Conclusion: Abd-El-Barr's point is a reliable radiographic landmark that provides accurate and safe docking during minimally invasive lumbar decompression. Validated through anatomical dissection, it has the potential to standardize docking, provide efficient surgical workflow, and reduce variability across various surgeon experience levels.

Clinical relevance: Using this landmark as a docking point, it is hoped that surgeons can make mininally invasive spine surgery, whether tubular or endoscopic, safer and more efficient, thus helping patients recover faster.

Level of evidence: 5: