Objectives  Expandable transforaminal interbody fusion (TLIF) devices have been developed to introduce more segmental lordosis through a narrow operative corridor, but there are concerns about the degree of achievable correction with a small graft footprint. In this report, we describe the technical nuances associated with placing bilateral expandable cages for correction of iatrogenic deformity. Materials and Methods  A 60-year-old female with symptomatic global sagittal malalignment and a severe lumbar kyphotic deformity after five prior lumbar surgeries presented to our institution. We performed multilevel posterior column osteotomies, a L3-4 intradiscal osteotomy, and placed bilateral lordotic expandable TLIF cages at the level of maximum segmental kyphosis. Results  We achieve a 21-degree correction of the patient\'s focal kyphotic deformity and restoration of the patient global sagittal alignment. Conclusion  This case demonstrates both the feasibility and utility of placing bilateral expandable TLIF cages at a single disc space in the setting of severe focal sagittal malalignment. This technique expands the implant footprint and, when coupled with an intradiscal osteotomy, allows for a significant restoration of segmental lordosis.

UNASSIGNED: The aim of the study was to assess the role of kyphoplasty and expandable intravertebral implants in the treatment of traumatic vertebral compression fractures.
UNASSIGNED: This is a systematic review.
UNASSIGNED: A bibliographic search was carried out in the PubMed/MEDLINE database according to PRISMA guidelines regarding kyphoplasty and expandable intravertebral implants in the treatment of traumatic thoracolumbar vertebral fractures.
UNASSIGNED: A total of 611 records were screened. In total, 51 studies were obtained referring to traumatic vertebral fractures treated with kyphoplasty; however, of these, only studies addressing traumatic burst fractures were selected, resulting in 12 studies: 10 about kyphoplasty and 2 regarding armed kyphoplasty. In all studies, there was a statistically significant improvement in clinical and functional parameters, restoration of vertebral height and decreasing of vertebral and segmental kyphosis. Overall, there was only a residual loss of height and a slight increase in kyphosis throughout the follow-up period, while complications consisted essentially of cement leakage, all with no clinical repercussions.
UNASSIGNED: After the discussion, where we address the concepts of direct and indirect reduction, the association of kyphoplasty with pedicle fixation, the potential advantages of expandable intravertebral implants, as well as the vertebral body type of filling in kyphoplasty, it is concluded that kyphoplasty demonstrates favorable outcomes as a method of posterior percutaneous transpedicular access for reconstruction of the anterior column in burst fractures. It allows for the reconstruction of the vertebral body closer to its original anatomy, carried out in a minimally invasive and safe way, which provides a clinical-functional and imaging improvement maintained at the medium-long term.

Oblique lateral interbody fusion (OLIF) surgery is a minimally invasive spinal surgery technique that has become increasingly popular in recent years. The primary objective of the current study was to design a minimally invasive expandable fusion device that can reduce iatrogenic nerve damage and minimize endplate damage during OLIF surgery, while restoring intervertebral height and alignment. The second objective was to use finite element analysis to evaluate the biomechanical stability of the newly designed expandable fusion device after implantation into the intervertebral space.
A new bidirectional expandable cage was designed in this study. A finite element model (FEM) of L3-L5 lumbar segment was modified to simulate decompression and fusion. The modified FEMs were constructed in the following cases: intact model, bidirectional expandable cage (alone, with unilateral pedicle screws [UPSs], and with bilateral pedicle screws [BPSs]) model, conventional OLIF cage (alone, with UPSs, and with BPSs) model. To simulate physiological loadings, the models were subjected to a follower compressive pre-load of 400 N, in addition to 8.0 Nm of flexion, extension, lateral bending, and axial rotation moments.
All modified FEMs exhibited a significant reduction in motion at L3-L5 compared to the intact model. Among the fusion models, the bidirectional expandable cage (BEC) with BPS model displayed the highest stiffness and demonstrated a reduced range of motion (48.5%-75.7%). Additionally, the peak stress on the endplate in the conventional OLIF cage (Conv-OLIF) model was generally lower than that in the BEC models. The cage in the BEC ALONE model exhibited the highest stress (93.87-176.3 MPa) on the endplate in most motion modes, while the cage in the Conv-OLIF+BPS model had the lowest stress (16.67-30.58 MPa) on the endplate in most motion modes. The maximum stress on the fixation in the BEC fusion models was generally lower than that in the Conv-OLIF fusion group under the same loading conditions. The OLIF ALONE model had the lowest stress on the adjacent disc, while the stress level in the BEC ALONE model was very close to it.
The BEC implanted models had higher stiffness, and more proper stress distribution on the posterior fixation was comparable to that of the Conv-OLIF models. However, the endplate stress peaks and cage stress peaks of the BEC models were slightly higher than those of the Conv-OLIF models, though still within a clinically acceptable range. Taking into account both biomechanical and clinical perspectives, BEC-assisted unilateral pedicle screw fixation meet clinical demand and may serve as a viable alternative to Conv-OLIF fusion.

UNASSIGNED: The FlareHawk Interbody Fusion System is a family of lumbar interbody fusion devices (IBFDs) that include FlareHawk7, FlareHawk9, FlareHawk11, TiHawk7, TiHawk9, and TiHawk11. These IBFDs offer a new line of multi-planar expandable interbody devices designed to provide mechanical stability, promote arthrodesis, and allow for restoration of disc height and lordosis through a minimal insertion profile during standard open and minimally invasive posterior lumbar fusion procedures. The two-piece interbody cage design consists of a PEEK outer shell that expands in width, height, and lordosis with the insertion of a titanium shim. Once expanded, the open architecture design allows for ample graft delivery into the disc space.
UNASSIGNED: The design and unique features of the FlareHawk family of expandable fusion cages are described. The indications for their use are discussed. Early clinical and radiographic outcome studies using the FlareHawk Interbody Fusion System are reviewed, and properties of competitor products are outlined.
UNASSIGNED: The FlareHawk multi-planar expandable interbody fusion cage is unique amongst the many lumbar fusion cages currently on the market. The multi-planar expansion, open architecture, and adaptive geometry set it apart from its competitors.

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Background Clinical performance, anterior knee stability, and isokinetic strength after anterior cruciate ligament (ACL) reconstruction with hamstring autografts are mainly influenced by graft selection, femoral tunnel preparation, and type of femoral fixation. Expandable femoral fixation devices are expected to provide a stronger initial fixation with circular graft compression, a blind-ended tunnel in the femur with less enlargement, and a theoretical double-band ACL equivalent through graft rotation. This study aimed to evaluate isokinetic strength and functional capacity after ACL reconstruction with hamstring tendons using two different anatomical femoral fixation techniques (expandable vs fixed-looped button). Methodology A total of 48 male patients with ACL deficient knees were randomized to two different femoral fixation groups, namely, the expandable (AperFix) and the standard cortical (Button) group. The primary outcome measures were isokinetic hamstrings and quadriceps strength capabilities and the hamstrings/quadriceps ratio at 60 degrees/second (°/s) and 180°/s using a Cybex before and at three, six, nine, 12, and 24 months after surgery. Secondary measurements were anteroposterior knee stability at two years (using KT-1000 arthrometer) and the functional outcome using the International Knee Documentation Committee (IKDC 2000) form, the Tegner activity scale, and the Lysholm knee score. Data were compared using a paired t-test and analysis of variance, with a p < 0.05 level of significance. Results Most patients regained the 60°/s quadriceps strength between three and 12 months (62.5% for the Button group vs. 50% for the AperFix group), as well as the 180°/s strength (79.17% vs 70.83%); however, at the 24-month evaluation, seven (29.17%) patients in the Button group and five (20.83%) in the AperFix group had significant deficits. The 60°/s flexor strength was regained in the first six months in 19 (79.17%) patients in the Button group and in 16 (66.7%) patients in the AperFix group, whereas the percentages for the 180°/s strength were 79.17% and 75%, respectively. Beyond the 24-month evaluation, only three (12.5%) patients in the Button group and four (16.67%) in the AperFix group had significant flexor deficits. Regarding the H/Q ratio, at 60°/s, the mean recovery time was six and 7.5 months for the Button and AperFix groups, respectively, whereas 15 and 12 patients, respectively, did not recover during the two-year duration. At 180°/s, a mean recovery time of six months was needed for the button group, and nine patients did not recover two years later. For the AperFix group, nine months were needed, and 12 patients did not recover in two years. Clinical performance and anterior knee stability showed no statistically significant differences between groups. Conclusions Although there were no significant differences in clinical performance, knee stability, and isokinetic strength testing between expandable and cortical button femoral fixation groups, return to play was doubtful at two years postoperatively.

METHODS: Retrospective cohort study.
OBJECTIVE: To compare the radiographic and clinical outcomes of static versus expandable interbody cages in transforaminal lumbar interbody fusion using minimally invasive surgery (MIS-TLIF).
BACKGROUND: Expandable interbody cages may potentially improve radiographic and clinical outcomes following MIS-TLIF compared to static pages, but at a potentially higher cost and increased rates of subsidence.
METHODS: A retrospective chart review of 1- and 2-level MIS-TLIFs performed from 2014 to 2020 was reviewed. Radiographic measurements were obtained preoperatively, 6 weeks postoperatively, and at final follow-up. Patient-reported outcome measures (PROMs) including the Oswestry Disability Index, Visual Analog Scale (VAS) back, and VAS leg were evaluated. Multivariate linear regression analysis determined the effect of cage type on the change in PROMs, controlling for demographic characteristics. Alpha was set at 0.05.
RESULTS: A total of 221 patients underwent MIS-TLIF including 136 static and 85 expandable cages. Expandable cages had significantly greater anterior (static: 11.41 mm vs. expandable: 13.11 mm, p <0.001) and posterior disk heights (static: 7.22 mm vs. expandable: 8.11 mm, p <0.001) at 1-year follow-up. Expandable cages offered similar improvements in segmental lordosis at 6 weeks (static: 1.69° vs. expandable: 2.81°, p =0.243), but segmental lordosis was better maintained with expandable cages leading to significant differences at 1-year follow-up (static: 0.86° vs. expandable: 2.45°, p =0.001). No significant differences were noted in total complication (static: 12.5% vs. expandable: 16.5%, p =0.191) or cage subsidence rates (static: 19.7% vs. expandable: 22.4%, p =0.502) groups at 1-year follow-up.
CONCLUSIONS: Expandable devices provide greater improvements in radiographic measurements including anterior disk height, posterior disk height, and segmental lordosis, but this did not lead to significant improvements in PROMs, complication rates, subsidence rates, or subsidence distance.

Lateral lumbar interbody fusion (LLIF) has paved a way for minimally invasive surgical treatment of a wide variety of spine pathologies. Interbody devices are used to stabilize painful disc levels, provide indirect decompression of neural elements, correct deformity, restore lordosis, and provide a sound durable fusion. Through the years, new static and expandable interbody devices have been developed in an attempt to improve radiographic and clinical outcomes in lumbar spine surgery. The purpose of this article is to explore the advantages and disadvantages between static and expandable interbody devices when used in LLIF. Specifically, this article addresses the differences in subsidence, indirect decompression, restoration of lumbar lordosis, complications, patient-reported outcomes, and cost between static and expandable interbody devices.

UNASSIGNED: Vertebral body replacement (VBR) cages are commonly implanted to reconstruct the cervical vertebrae in cases of tumour, trauma, spondylodiscitis, and degeneration. Expandable cages have been widely used for this purpose; however, the lacking congruence at the implant-bone interface and consequent implant displacement were considered as a serious drawback of such systems. Aim of this study is to evaluate the early clinical and radiological outcome of a modern in situ not only expandable but also angulable cervical corpectomy cage system.
UNASSIGNED: A total of 42 patients who underwent a single or multilevel cervical VBR procedure were included and retrospectively evaluated in this single-centre case series. The neurological status was assessed using American Spinal Injury Association (ASIA) score. Complications were categorized into surgical (including implant-associated) and general medical. Radiographic parameters included regional angulation, segmental height, and coronal alignment.
UNASSIGNED: Mean age was 59.5 ± 20.6 years. The recorded ASIA score improved postoperatively by 10 points (p  0.0001). Surgical including implant-associated complication rates were 19.05%. Radiographic evaluation showed a height gain of 11.2 mm (p < 0.0001), lordotic correction of 7° (p < 0.0001), and coronal alignment of 3° (p < 0.0001). At the last follow-up, loss of angulation correction of 1.9° (p  0.0002), subsidence of 1.92 mm (p  0.0006), and fusion rates of 68.42% were observed.
UNASSIGNED: The use of an in situ angulable and expandable cage system in cervical VBR seems to offer better results compared to conventional static or expandable cages regarding segmental height gain, lordotic correction, and clinical improvement as well as low complication and revision rates. Significant height gain in multilevel surgeries is associated with higher rates of implant-associated complications.

BACKGROUND: Static interbody spacers are standard of care for minimally invasive lateral lumbar interbody fusion (MIS LLIF). However, placement of large static interbody spacers typically requires multiple trialing, endplate preparation, and forceful impaction. A lateral expandable interbody spacer with adjustable lordosis can be inserted at a reduced height, to optimize the endplate-to-endplate fit. This study describes radiographic and clinical outcomes in patients treated using lateral titanium expandable interbody spacers with adjustable lordosis using MIS LLIF.
METHODS: This is a single-surgeon, retrospective, institutional review board-exempt chart review of 24 consecutive patients who underwent MIS LLIF at 1-2 contiguous level(s) using expandable spacers with adjustable lordosis. Radiographic and clinical functional outcomes were collected and compared at preoperative and postoperative time points up to 24 months. Parametric and nonparametric tests were used when appropriate. Statistical results were significant if P < .05.
RESULTS: Twenty-four consecutive patients were evaluated with an average age of 57.8 ± 12.6 years; 45.8% were female. Visual analog scale for back pain improved by 7.3 ± 1.0 points, whereas Oswestry Disability Index scores improved by a mean of 67.5 ± 11.3 points at 24 months (P < .001). Lumbar lordosis improved by a mean of 6.3 ± 10.1° at 24 months (P < .001). There were 29 spinal levels, with 41.4% at L4-5 and 34.5% at L3-4. Anterior, middle, and posterior disc height significantly increased at 24 months by means of 4.5 ± 2.9 mm, 4.0 ± 2.8 mm, and 2.6 ± 1.9 mm, respectively (P < .001). Neuroforaminal height significantly improved by 3.3 ± 3.9 mm at 24 months (P < .001). Segmental lordosis improved by 3.6 ± 3.0° at 24 months.
CONCLUSIONS: This study showed significant positive clinical and radiographic outcomes for patients who underwent MIS LLIF using expandable interbody spacers with adjustable lordosis. Correction of sagittal alignment was achieved and maintained up to 2-year follow-up. The use of expandable spacers with adjustable lordosis was shown to be safe and effective in this cohort.
METHODS: 3.