Impact of Supine versus Prone Positioning on Segmental Lumbar Lordosis in Patients Undergoing ALIF Followed by PSF: A Comparative Study
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SUBMITTER: Sadeghzadeh S
PROVIDER: S-EPMC11204788 | biostudies-literature | 2024 Jun
REPOSITORIES: biostudies-literature
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Project description:PurposeTo report the results of a prospective study that compares small bowel doses during prone and supine pelvic intensity modulated radiation therapy.Methods and materialsTen patients receiving pelvic radiation therapy each had 2 intensity modulated radiation therapy plans generated: supine and prone on a belly board (PBB). Computed tomography on rails was performed weekly throughout treatment in both positions (10 scans per patient). After image fusion, doses to small bowel (SB) loops and clinical target volume were calculated for each scan. Changes between the planned and received doses were analyzed and compared between positions. The impact of bladder filling on SB dose was also assessed.ResultsProne treatment was associated with significantly lower volumes of SB receiving ≥20 Gy. On average, prone on a belly board positioning reduced the volume of SB receiving a given dose of radiation by 28% compared with supine positioning. Target coverage throughout the treatment course was similar in both positions with an average minimum clinical target volume dose of 88% of the prescribed prone dose and 89% of the supine (P = .54). For supine treatment, SB dose was inversely correlated with bladder filling (P = .001-.013; P > .15 for prone). For 96% of treatments, the volume of SB that received a given dose deviated >10% from the plan. The deviation between the planned and delivered doses to SB did not differ significantly between the positions.ConclusionsProne positioning on a belly board during pelvic IMRT consistently reduces the volume of SB that receives a broad range of radiation doses. Prone IMRT is associated with interfraction dose variation to SB that is similar to that of supine positioning. These findings suggest that prone positioning with daily image guided radiation therapy is an effective method for maximizing SB sparing during pelvic IMRT.
| S-EPMC5514253 | biostudies-literature
Project description:Standing radiographs play an important role in the characterization of spinal sagittal alignment, as they depict the spine under physiologic loading conditions. However, there is no commonly available method to apply the lumbar lordosis of standing radiographs to supine CT-based virtual 3D models of the lumbar spine. We aimed to develop a method for the sagittal rigid-body registration of vertebrae to standing radiographs, using the exact geometry reconstructed from CT-data. In a cohort of 50 patients with monosegmental spinal degeneration, segmentation and registration of the lumbar vertebrae and sacrum were performed by two independent investigators. Intersegmental angles and lumbar lordosis were measured both in CT scans and radiographs. Vertebrae were registered using the X-ray module of Materialise Mimics software. Postregistrational midsagittal sections were constructed of the sagittal midplane sections of the registered 3D lumbar spine geometries. Mean Hausdorff distance was measured between corresponding registered vertebral geometries. The registration process minimized the difference between the X-rays' and postregistrational midsagittal sections' lordoses. Intra- and inter-rater reliability was excellent based on angle and mean Hausdorff distance measurements. We propose an accessible, accurate, and reproducible method for creating patient-specific 3D geometries of the lumbar spine that accurately represent spinal sagittal alignment in the standing position.
| S-EPMC9701766 | biostudies-literature
Project description:BackgroundControversy exists regarding the ability of posterior (transforaminal) lumbar interbody fusion (PLIF/TLIF) to achieve lordosis. We hypothesized that an interbody device (IBD) designed for positioning in the anterior disc space produces greater lordosis than IBDs designed for straight-in positioning. The purpose of this study is to determine if using either an anterior-position or straight-in position IBD design were associated with successful achievement of postoperative lordosis.MethodsA consecutive series of patients undergoing a undergoing a single-level, posterior open midline (transforaminal) lumbar interbody fusion procedure for degenerative spine conditions during a time period when the two types of interbody devices were being used at surgeon discretion were identified from a multi-surgeon academic training center. Patient demographics and radiographic measures including surgical level lordosis (SLL), anterior disc height, middle disc height, posterior disc height, IBD height, and IBD insertion depth were measured on preop, immediate postop, and one-year postop standing radiographs using PACS. Group comparison and regression analysis were performed using SPSS.ResultsSixty-one patients were included (n=37 anterior, n=34 straight-in). Mean age was 59.8±8.7 years, 32 (52%) were female. There was no difference between IBD type (anterior vs. straight-in) for mean Pre-op SLL (19±7° vs. 20±6°, p=0.7), Post-op SLL (21±5° vs 21±6°, p=0.5), or Change in SLL (2±4° vs. 1±5°, p=0.2). Regression analysis showed that Pre-op SLL was the only variable associated with Change in SLL (Beta = negative 0.48, p=0.000). While the mean Change in SLL could be considered clinically insignificant, there was wide variability: from a loss of 9° to a gain of 13°. Gain of lordosis >5° only occurred when Pre-op SLL was <21°, and loss of lordosis >5° only occurred when Pre-op SLL was >21°.ConclusionsWhile group averages showed an insignificant change in segmental lordosis following a posterior (transforaminal) interbody fusion regardless of interbody device type, pre-operative lordosis was correlated with a clinically significant change in segmental lordosis. Preoperative hypolordotic discs were more likely to gain significant lordosis, while preoperative hyperlordotic discs were more likely to lose significant lordosis. Surgeon awareness of this tendency can help guide surgical planning and technique.
| S-EPMC9386101 | biostudies-literature
Project description:Study designRetrospective Case-Series.ObjectivesDue to heterogeneity in previous studies, the effect of MI-TLIF on postoperative segmental lordosis (SL) and lumbar lordosis (LL) remains unclear. Therefore, we aim to identify radiographic factors associated with lordosis after surgery in a homogenous series of MI-TLIF patients.MethodsA single-center retrospective review identified consecutive patients who underwent single-level MI-TLIF for grade 1 degenerative spondylolisthesis from 2015-2020. All surgeries underwent unilateral facetectomies and a contralateral facet release with expandable interbody cages. PROs included the ODI and NRS-BP for low-back pain. Radiographic measures included SL, disc height, percent spondylolisthesis, cage positioning, LL, PI-LL mismatch, sacral-slope, and pelvic-tilt. Surgeries were considered "lordosing" if the change in postoperative SL was ≥ +4° and "kyphosing" if ≤ -4°. Predictors of change in SL/LL were evaluated using Pearson's correlation and multivariable regression.ResultsA total of 73 patients with an average follow-up of 22.5 (range 12-61) months were included. Patients experienced significant improvements in ODI (29% ± 22% improvement, P < .001) and NRS-BP (3.3 ± 3 point improvement, P < .001). There was a significant increase in mean SL (Δ3.43° ± 4.37°, P < .001) while LL (Δ0.17° ± 6.98°, P > .05) remained stable. Thirty-eight (52%) patients experienced lordosing MI-TLIFs, compared to 4 (5%) kyphosing and 31 (43%) neutral MI-TLIFs. A lower preoperative SL and more anterior cage placement were associated with the greatest improvement in SL (β = -.45° P = .001, β = 15.06° P < .001, respectively).ConclusionsIn our series, the majority of patients experienced lordosing or neutral MI-TLIFs (n = 69, 95%). Preoperative radiographic alignment and anterior cage placement were significantly associated with target SL following MI-TLIF.
| S-EPMC11877597 | biostudies-literature
Project description:Prone setup has been advocated to improve organ sparing in whole breast radiotherapy without impairing breast coverage. We evaluate the dosimetric advantage of prone setup for the right breast and look for predictors of the gain. Right breast cancer patients treated in 2010-2013 who had a dual supine and prone planning were retrospectively identified. A penalty score was computed from the mean absolute dose deviation to heart, lungs, breasts, and tumor bed for each patient's supine and prone plan. Dosimetric advantage of prone was assessed by the reduction of penalty score from supine to prone. The effect of patients' characteristics on the reduction of penalty was analyzed using robust linear regression. A total of 146 patients with right breast dual plans were identified. Prone compared to supine reduced the penalty score in 119 patients (81.5%). Lung doses were reduced by 70.8%, from 4.8 Gy supine to 1.4 Gy prone. Among patient's characteristics, the only significant predictors were the breast volumes, but no cutoff could identify when prone would be less advantageous than supine. Prone was associated with a dosimetric advantage in most patients. It sets a benchmark of achievable lung dose reduction.Trial registration: ClinicalTrials.gov NCT02237469, HUGProne, September 11, 2014, retrospectively registered.
| S-EPMC8752750 | biostudies-literature
Project description:Study Design Retrospective review. Objective The purpose of this study was to determine the radiographic impact of a transforaminal lumbar interbody fusion (TLIF) versus a cantilever TLIF technique on segmental lordosis, segmental coronal alignment, and disk height. Methods A retrospective review was done of all patients undergoing TLIF procedures from 2006 to 2011 by three spine surgeons. Traditional TLIF versus cantilever TLIF results were compared, and radiographic outcomes were assessed. Results One hundred one patients were included in the study. Patients undergoing the cantilever TLIF procedure had a significantly greater change in segmental lordosis and disk height compared with those who underwent the traditional procedure (p > 0.0001). Conclusions The cantilever TLIF technique can lead to greater change in segmental lordosis based upon radiographic outcomes.
| S-EPMC4836934 | biostudies-other
Project description:This study aimed to clarify the differences in radiotherapy dose characteristics and delivery efficiency between the supine and prone positions in patients with prostate cancer using the CyberKnife. The planning computed tomography (CT) and delineations of the prone position were obtained by rotating the supine CT images with delineations of 180° using image processing software. The optimization parameters for planning target volume (PTV) and organs at risk (OARs) were based on the prone position. The optimization parameters determined for the prone position were applied to the supine position for optimization and dose calculation. The dosimetric characteristics of the PTV and OARs, and delivery efficiency were compared between the two different patient positions. The plans in the prone position resulted in better PTV conformity index (nCI), rectum V90%, V80%, V75%, V50% and bladder V50%. A significant difference was observed in treatment time and depth along the central axis (dCAX) between the two plans. The mean treatment time per fraction and dCAX for the supine and prone positions were 20.9 ± 1.7 min versus 19.8 ± 1.3 min (P = 0.019) and 151.1 ± 33.6 mm versus 233.2 ± 8.8 mm (P < 0.001), respectively. In this study the prone position was found to improve dosimetric characteristics and delivery efficiency compared with the supine position during prostate cancer treatment with the CyberKnife.
| S-EPMC9855311 | biostudies-literature
Project description:Abstract Lumbar lordosis is a key adaptation to bipedal locomotion in the human lineage. Dorsoventral spinal curvatures enable the body's center of mass to be positioned above the hip, knee, and ankle joints, and minimize the muscular effort required for postural control and locomotion. Previous studies have suggested that Neandertals had less lordotic (ventrally convex) lumbar columns than modern humans, which contributed to historical perceptions of postural and locomotor differences between the two groups. Quantifying lower back curvature in extinct hominins is entirely reliant upon bony correlates of overall lordosis, since the latter is significantly influenced by soft tissue structures (e.g. intervertebral discs). Here, we investigate sexual dimorphism, ancestry, and lifestyle effects on lumbar vertebral body wedging and inferior articular facet angulation, two features previously shown to be significantly correlated with overall lordosis in living individuals, in a large sample of modern humans and Neandertals. Our results demonstrate significant differences between postindustrial cadaveric remains and archaeological samples of people that lived preindustrial lifestyles. We suggest these differences are related to activity and other aspects of lifestyle rather than innate population (ancestry) differences. Neandertal bony correlates of lumbar lordosis are significantly different from all human samples except preindustrial males. Therefore, although Neandertals demonstrate more bony kyphotic wedging than most modern humans, we cast doubt on proposed locomotor and postural differences between the two lineages based on inferred lumbar lordosis (or lack thereof), and we recommend future research compare fossils to modern humans from varied populations and not just recent, postindustrial samples.
| S-EPMC9801964 | biostudies-literature
Project description:Single-prone-lateral (PL) positioning is a new technique that allows for simultaneous anterior and posterior lumbar spine surgery. However, there is a concern regarding the risk of lumbar plexus injury in PL positioning. This study compared the risk of lumbar plexus damage and the overall safety profile of a modified PL (mPL) position to the standard PL (sPL) position for lateral lumbar spine fusion surgery. A crossover soft cadaveric study was conducted with two raters examining the comparative outcomes of position A: sPL and position B: mPL. The mPL position differs from the sPL position in that the ipsilateral arm is placed at the side of the body rather than above the head. To assess positive results (no lumbar plexus injury) between positions A and B, a mixed effects logistic regression model was utilized. The odds ratio of a good result between positions B and A was also determined. The odds ratio of the favorable outcome between position B and A was 1.77, indicating significantly higher odds of a favorable outcome in the modified position B than in the control or position A. The mPL positioning outperformed the sPL positioning in terms of safety and efficacy for lateral lumbar spine fusion. The mPL positioning may reduce the risk of lumbar plexus injury by allowing for a more direct approach to the lumbar spine and by avoiding excessive stretching of the lumbar plexus.
| S-EPMC10772666 | biostudies-literature
Project description:Background: Femoral derotation osteotomy (FDO) for correction of internal rotation gait resulting from cerebral palsy (CP) can be performed with the patient in the prone or supine position. It is not known whether patient positioning during FDO affects the change in hip rotation. Purpose/Questions: We sought to compare the change in hip rotation following FDO performed on patients with CP in the prone or supine position through kinematic analysis. Methods: We conducted a consecutive retrospective cohort study of children with CP, ages 3 to 18 years and with Gross Motor Function Classification System (GMFCS) levels I to III, who underwent prone or supine FDO and pre- and postoperative motion analysis. The prone group included 37 patients (68 limbs) between 1990 and 1995. The supine group included 26 patients (47 limbs) between 2005 and 2015. The groups were matched for gender, age, and GMFCS level. The primary outcome was hip rotation in degrees during stance phase. Secondary outcomes included temporal-spatial parameters, hip abduction, hip and knee extension, and hip and knee passive range of motion (ROM). Results: The prone group had more bilateral patients (100%) than the supine group (81%). The supine group underwent more concomitant procedures. There was no difference between the prone and supine groups in postoperative stance hip rotation; both groups had significantly improved stance hip rotation, step width, and hip rotation passive ROM, pre- to postoperatively. Prone patients had improved postoperative hip extension, pelvic tilt, velocity, and cadence. Conclusions: There was no significant different in stance hip rotation between supine and prone FDO groups. Advocates of prone positioning for FDO suggest it allows more accurate assessment of rotation. Supine positioning may be more convenient when additional procedures are required. Based on our findings, either approach can achieve the desired result.
| S-EPMC8753547 | biostudies-literature