Slip Percentage Research Articles

Transforaminal Endoscopic Lumbar Discectomy versus Coblation Nucleoplasty Combined with Collagenase Chemonucleolysis for Lumbar Disc Herniation with Grade I Degenerative Spondylolisthesis.

To investigate the short-term clinical effect of transforaminal endoscopic lumbar discectomy (TELD) versus coblation nucleoplasty (CN) combined with collagenase chemonucleolysis (CCNL) in the treatment of lumbar disc herniation (LDH) with grade I degenerative spondylolisthesis. From January 2019 to December 2020, 60 patients who had LDH with grade I degenerative spondylolisthesis were divided into two groups. Group A adopted TELD while Group B adopted CN combined with CCNL. The surgical efficacy was evaluated according to the visual analogue scale (VAS), oswestry disability index (ODI), quality of recovery-15 (QoR-15), and modified MacNab criteria. Imaging findings including lumbar lordosis (LL), segmental lordosis angle (SL), slip percentage (SP), and disc height (DH) were compared between the two groups pre-operation and at the last follow-up. VAS (back and leg), ODI, and QoR-15 were significantly decreased at each time point after operation in all groups. There were significant differences in VAS (back and leg), ODI, and QoR-15 between the two groups at 3days post-operation (P<0.05), VAS (leg), ODI, and QoR-15 at 3months post-operative (P<0.05), and QoR-15 at 6months post-operative (P<0.05). There was no significant difference in LL, SL, SP, and DH between the two groups at the last follow-up (P>0.05). Both the two operations can relieve the symptoms of lower back and leg pain in patients, and neither of the two operations caused further progress of lumbar spondylolisthesis. Compared with CN combined with CCNL, TELD had more significant improvement in early lower back and leg pain and shorter post-operative duration of hospitalization. The trial was registered on ClinicalTrials.gov (ChiCTR2300076809).

A Study of The Work of The Flap Plow in Silty Loam Soil (Mould Board Plow)

This study was carried out in one of the agricultural fields affiliated to the University of Basra in the year 2022, where the study included the use of the tractor type (Massey Ferguson MF 375) with the rotary cultivator at different speeds, as well as the use of different depths to study the effect of this on silty clay soils. In this experiment, the effect of two factors was studied. They are the plowing depths (0.13, 0.185, 0.235 m) and the plowing speed of the tractor with the tipper plow, which ranged from (0.977, 1.347, 1.805 m/sec) in the studied technical indicators, which included practical productivity, the real efficiency of the symptoms, soil resistance to penetration, and the percentage of slip. The research was carried out according to the randomized complete block design and with four replications using the practical experiment method, where the statistical results and differences tests were analyzed in a manner with the least significant difference at the level of (0.05). To the decrease in the practical productivity and field efficiency of the plows with an increase in soil resistance to penetration and the percentage of slippage, and the plowing depth exceeded 0.15 meters over the plowing depths (0.235, 0.185) meters in achieving the highest rate of practical productivity with the highest field efficiency of the plow, as well as achieving the lowest soil resistance rate For penetration with the lowest anti-overturning ratio, while increasing the practical speed of the plow from 0.997 to 1.347 m/sec and then to 1.805 m/ sec led to an increase in practical productivity with a decrease in the field efficiency of the plow as well as an increase in soil resistance to penetration with an increase in the slip percentage.

Clinical and Radiological Predictors of Slower and Non-Improvement Following Surgical Treatment of L4-5 Degenerative Spondylolisthesis: Preliminary Results.

Retrospective cohort. To identify the predictors of slower and non-improvement following surgical treatment of L4-5 degenerative lumbar spondylolisthesis (DLS). There is limited evidence regarding clinical and radiological predictors of slower and non-improvement following surgery for L4-5 DLS. Patients who underwent minimally invasive decompression or fusion for L4-5 DLS and had a minimum of 1-year follow-up were included. Outcome measures were: (1) minimal clinically important difference (MCID), (2) patient acceptable symptom state (PASS), and (3) global rating change (GRC). Clinical variables analyzed for predictors were age, gender, body mass index (BMI), surgery type, comorbidities, anxiety, depression, smoking, osteoporosis, and preoperative patient reported outcome measures (PROMs) (Oswestry Disability Index, ODI; Visual Analog Scale, VAS back and leg; 12-Item Short Form Survey Physical Component Score, SF-12 PCS). Radiological variables analyzed were slip percentage, translational and angular motion, facet diastasis/cyst/orientation, laterolisthesis, disc height, scoliosis, main and fractional curve Cobb angles, and spinopelvic parameters. 233 patients (37% decompression, 63% fusion) were included. At <3 months, high pelvic tilt (PT) (OR 0.92, P 0.02) and depression (OR 0.28, P 0.02) were predictors of MCID non-achievement and GRC non-betterment, respectively. Neither retained significance at >6 months and hence, were identified as predictors of slower improvement. At >6 months, low preoperative VAS leg (OR 1.26, P 0.01) and high facet orientation (OR 0.95, P 0.03) were predictors of MCID non-achievement, high L4-5 slip percentage (OR 0.86, P 0.03) and L5-S1 angular motion (OR 0.78, P 0.01) were predictors of GRC non-betterment, and high preoperative ODI (OR 0.96, P 0.04) was a predictor of PASS non-achievement. High PT and depression were predictors of slower improvement and low preoperative leg pain, high disability, high facet orientation, high slip percentage, and L5-S1 angular motion were predictors of non-improvement. However, these are preliminary findings and further studies with homogeneous cohorts are required to establish these findings.

The relationship between paraspinal muscle atrophy and degenerative lumbar spondylolisthesis at the L4/5 level

BACKGROUND/CONTEXTDegenerative lumbar spondylolisthesis (DLS) is a prevalent spinal condition that can result in significant disability. DLS is thought to result from a combination of disc and facet joint degeneration, as well as various biological, biomechanical, and behavioral factors. One hypothesis is the progressive degeneration of segmental stabilizers, notably the paraspinal muscles, contributes to a vicious cycle of increasing slippage. PURPOSETo examine the correlation between paraspinal muscle status on MRI and severity of slippage in patients with symptomatic DLS. STUDY DESIGN/SETTINGRetrospective cross-sectional study at an academic tertiary care center. PATIENT SAMPLEPatients who underwent surgery for DLS at the L4/5 level between 2016–2018 were included. Those with multilevel DLS or insufficient imaging were excluded. OUTCOME MEASURESThe percentage of relative slippage (RS) at the L4/5 level evaluated on standing lateral radiographs. Muscle morphology measurements including functional cross-sectional area (fCSA), body height normalized functional cross-sectional area (HI) of Psoas, erector spinae (ES) and multifidus muscle (MF) and fatty infiltration (FI) of ES and MF were measured on axial MR. Disc degeneration and facet joint arthritis were classified according to Pfirrmann and Weishaupt, respectively. METHODSDescriptive and comparative statistics, univariable and multivariable linear regression models were utilized to examine the associations between RS and muscle parameters, adjusting for confounders sex, age, BMI, segmental degeneration, and back pain severity and symptom duration. RESULTSThe study analyzed 138 out of 183 patients screened for eligibility. The median age of all patients was 69.5 years (IQR 62 to 73), average BMI was 29.1 (SD±5.1) and average preoperative ODI was 46.4 (SD±16.3). Patients with Meyerding-Grade 2 (M2, N=25) exhibited higher Pfirrmann scores, lower MFfCSA and MFHI, and lower BMI, but significantly more fatty infiltration in the MF and ES muscles compared to those with Meyerding Grade 1 (M1). Univariable linear regression showed that each cm2 decrease in MFfCSA was associated with a 0.9%-point increase in RS (95% CI -1.4 to - 0.4, p<.001), and each cm2/m2 decrease in MFHI was associated with an increase in slippage by 2.2%-points (95% CI -3.7 to -0.7, p=.004). Each 1%-point rise in ESFI and MFFI corresponded to 0.17%- (95% CI 0.05–0.3, p=.01) and 0.20%-point (95% CI 0.1–0.3 p<.001) increases in relative slippage, respectively. Notably, after adjusting for confounders, each cm2 increase in PsoasfCSA and cm2/m2 in PsoasHI was associated with an increase in relative slippage by 0.3% (95% CI 0.1–0.6, p=.004) and 1.1%-points (95% CI 0.4–1.7, p=.001). While MFfCSA tended to be negatively associated with slippage, this did not reach statistical significance (p=.105). However, each 1%-point increase in MFFI and ESFI corresponded to increases of 0.15% points (95% CI 0.05–0.24, p=.002) and 0.14% points (95% CI 0.01–0.27, p=.03) in relative slippage, respectively. CONCLUSIONThis study found a significant association between paraspinal muscle status and severity of slippage in DLS. Whereas higher degeneration of the ES and MF correlate with a higher degree of slippage, the opposite was found for the psoas. These findings suggest that progressive muscular imbalance between posterior and anterior paraspinal muscles could contribute to the progression of slippage in DLS.

Clinical Efficacy of Unilateral Dual-channel Endoscopic Lumbar Interbody Fusion for Lumbar Spondylolisthesis with Spinal Scoliosis.

Scoliosis associated with spondylolisthesis is a common phenomenon. Recent research has reported that scoliosis can spontaneously disappear after lumbar spinal fusion surgery. Researchers have advocated that, for scoliosis associated with vertebral slippage, surgery for the latter may be the only necessary intervention, while unnecessary surgery for scoliosis should be avoided. So we propose that minimally invasive techniques can achieve treatment effects similar to those of open surgery. Therefore, in this study, we aimed to investigate the clinical efficacy of unilateral dual-channel endoscopic lumbar interbody fusion (ULIF) for treating lumbar spondylolisthesis with spinal scoliosis. This study retrospectively analyzed patients with lumbar spondylolisthesis and spinal scoliosis who underwent ULIF between September 2021 and September 2023. Measurements of the Cobb angle, lumbar lordosis (LL) angle, sacral slope (SS), slip percentage (SP), slip angle (SA), L1 plumb line-S1 distance (LASD), and average intervertebral height (AIH) were taken preoperatively, immediately following surgery, 3 months after surgery, and at the final follow-up. The visual analogue scale (VAS), Oswestry disability index (ODI), and Japanese Orthopaedic Association (JOA) scoring systems were used to assess clinical results. The surgical efficacy was evaluated by comparing these parameters before and after surgery. Comparison of indicators within the same group was conducted using one-way repeated-measures analysis of variance or paired sample t-tests, whereas between-group differences were compared using an independent t-test. This study included 31 individuals who underwent surgery and completed follow-up. The follow-up period did not show a significant loss of corrective angles. Furthermore, the Cobb angle, SP, SA, and LASD significantly decreased after surgery, whereas the LL angle, SS, and AIH significantly increased (all p < 0.05). SP did not differ between the immediate postoperative period and the 3-month and final follow-up periods (p > 0.05). However, other parameters significantly improved during the follow-up period at all time points, except from 3 months to the final follow-up period (p > 0.05). Throughout the follow-up period, the lower back and leg pain VAS, ODI, and JOA scores considerably improved compared with the preoperative levels (p < 0.05). ULIF effectively treated lumbar spondylolisthesis with scoliosis, thereby reducing the degree of slip and scoliosis. By performing surgical reduction, fusion, and fixation only on the slipped segment, ULIF also had a corrective effect on the spinal lateral curvature, thereby avoiding the need for unnecessary scoliosis surgery. Moreover, the short-term efficacy was satisfactory, but the long-term efficacy requires further study.

Clinical and Radiological Outcomes of Full-Endoscopic Decompression for Lumbar Spinal Stenosis With Grade I Degenerative Spondylolisthesis: A Retrospective Study With a Minimum 1-Year Follow-up

BACKGROUND AND OBJECTIVES: Decompression without fusion is a surgical option for the treatment of lumbar spinal stenosis (LSS) with grade I degenerative spondylolisthesis (DS). However, the outcomes of full-endoscopic decompression remain unknown. This study aimed to investigate the clinical and radiological outcomes of lumbar full-endoscopic decompression for spinal stenosis with grade I DS. METHODS: A total 43 patients with LSS with grade I DS who underwent lumbar full-endoscopic unilateral laminotomy for bilateral decompression and were followed up for a minimum of 1 year were retrospectively reviewed. Data on demographic characteristics, operative details, radiological images, clinical outcomes, and complications were analyzed. RESULTS: Pain, evaluated using the visual analog scale, was significantly reduced in patients undergoing full-endoscopic decompression in both the leg and back; the Oswestry Disability Index scores also improved (P &lt; .001). MacNab's outcome classification was excellent or good in 95% of patients. One patient eventually needed the fusion surgery, and two patients required further diskectomy surgery because of recurrent symptoms. During follow-up, an increase in the vertebral slip was observed in 46.5% of the patients, but it was not statistically significant (P = .46). The progression of DS, defined as percentage of slip &gt;5%, was observed only in 7% of the patients. An increase in vertebral slip was not associated with the clinical outcomes. There was no difference in radiological outcomes, such as angular motion (P = .36) and translation (P = .13), compared with the preoperative state. The operation did not exacerbate spinal instability. Rather, fewer patients had spinal instability postoperatively. CONCLUSION: Endoscopic decompression alone has comparably good clinical outcomes with those of other surgical techniques in patients with LSS and DS. Few postoperative spinal instability occurred. Rather, the number of patients with instability decreased postoperatively. Full-endoscopic decompression may be a treatment option for patients with grade 1 DS.

Differences in the surgical management of degenerative lumbar spondylolisthesis based on self-reported sex: analysis of the CSORN prospective DLS study.

Surgical treatment of degenerative lumbar spondylolisthesis (DLS) reliably improves patient-reported quality of life; however, patient population heterogeneity, in addition to other factors, ensures ongoing equipoise in choosing the ideal surgical treatment. Surgeon preference for fusion or decompression alone influences surgical treatment decision-making. Meanwhile, at presentation, patient-reported outcome measures (PROMs) differ considerably between females and males. The aims of this study were to determine whether there exists a difference in the rates of decompression and fusion versus decompression alone based on patient-reported sex, and to determine if widely accepted indications for fusion justify any observed differences or if surgeon preference plays a role. This study is a retrospective cohort analysis of patients enrolled in the Canadian Spine Outcomes Research Network (CSORN) DLS study, a multicentered Canadian prospective study, investigating the surgical management and outcome of DLS. Decompression and fusion rates, patient characteristics, preoperative PROMs, and radiographic measures were compared between males and females before and after propensity score matching. In the unmatched cohort, female patients were more likely to undergo decompression and fusion than male patients. Females were more likely to have the recognized indications for fusion, including kyphotic disc angle, higher spondylolisthesis grade and slip percentage, and patient-reported back pain. Other radiographic findings associated with the decision to fuse, including facet effusion, facet distraction, or facet angle, were not more prevalent in females. After propensity score matching for demographic and radiographic characteristics, similar proportions of male and female patients underwent decompression and fusion and decompression alone. Although it remains unclear who should or should not undergo fusion, in addition to surgical decompression of DLS, female patients undergo fusion at a higher rate than their male counterparts. After matching baseline radiographic factors indicating fusion, this analysis showed that the decision to fuse was not biased by sex differences. Rather, the higher proportion of females undergoing fusion is largely explained by the radiographic and clinical indications for fusion, suggesting that specific clinical and anatomical features of this condition are indeed different between sexes.

Comparative Analysis of Three Posterior-Only Surgical Techniques for Isthmic L5-S1 Spondylolisthesis.

To compare adults with isthmic L5-S1 spondylolisthesis who were treated with three different surgical techniques: PS-only, TS, and transforaminal lumbar interbody fusion/posterior lumbar interbody fusion (TLIF/PLIF). This is a retrospective analysis of adults with L5-S1 isthmic spondylolisthesis (grade ≥2) who underwent primary all-posterior operations with pedicle screws. Patients were excluded if they had <1 year follow-up, anterior approaches, and trans-sacral fibular grafts. Patient demographics and surgical, radiographic, and clinical data were compared between groups based on the method of anterior column support: none (PS-only), TS, and TLIF/PLIF. Sixty patients met inclusion criteria (male patients 21, female patients 39, average age 47 ± 15 years, PS-only 16; TS 20; TLIF/PLIF 24). TS patients more commonly had high-grade slips and markedly greater slip percentage, lumbosacral kyphosis, and pelvic incidence. The three groups were similar for smoking status, visual analog scores/Oswestry Disability Index scores (VAS/ODI), surgical data, and average follow-up (40.1 ± 31.2 months). All groups had similarly notable improvements in Meyerding grade and lumbosacral angle. Slip reduction percentage was similar between groups. While there was a markedly higher overall complication rate for PS-only constructs, all groups had similarly notable improvements in ODI and VAS back scores. All-posterior techniques for L5-S1 isthmic spondylolisthesis resulted in excellent improvement in preoperative symptoms and HRQoL scores and similar radiographic alignment. Trans-sacral screws were more commonly used for high-grade slips. The use of anterior column support resulted in fewer overall complications than posterior-only instrumentation.

Percutaneous transforaminal endoscopic decompression with removal of the posterosuperior region underneath the slipping vertebral body for lumbar spinal stenosis with degenerative lumbar spondylolisthesis: a retrospective study

BackgroundPercutaneous transforaminal endoscopic decompression (PTED) is an ideal minimally invasive decompression technique for the treatment of lumbar spinal stenosis (LSS) with degenerative lumbar spondylolisthesis (DLS). The posterosuperior region underneath the slipping vertebral body (PRSVB) formed by DLS is an important factor exacerbating LSS in patients. Therefore, the necessity of removing the PRSVB during ventral decompression remains to be discussed. This study aimed to describe the procedure of PTED combined with the removal of the PRSVB and to evaluate the clinical outcomes.MethodsLSS with DLS was diagnosed in 44 consecutive patients at our institution from January 2019 to July 2021, and they underwent PTED combined with the removal of the PRSVB. All patients were followed up for at least 12 months. The clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry Disability Index (ODI), and modified MacNab criteria.ResultsThe mean age of the patients was 69.5 ± 7.1 years. The mean preoperative ODI score, VAS score of the low back, and VAS score of the leg were 68.3 ± 10.8, 5.8 ± 1.0, and 7.7 ± 1.1, respectively, which improved to 18.8 ± 5.0, 1.4 ± 0.8, and 1.6 ± 0.7, respectively, at 12 months postoperatively. The proportion of patients presenting “good” and “excellent” ratings according to the modified MacNab criteria was 93.2%. The percent slippage in spondylolisthesis preoperatively (16.0% ± 3.3%) and at the end of follow-up (15.8% ± 3.3%) did not differ significantly (p>0.05). One patient had a dural tear, and one patient had postoperative dysesthesia.ConclusionsIncreasing the removal of PRSVB during the PTED process may be a beneficial surgical procedure for alleviating clinical symptoms in patients with LSS and DLS. However, long-term follow-up is needed to study clinical effects.

Is it necessary to extend fusion to L4 when correcting pediatric L5-S1 spondylolisthesis?

The objective of this study was to investigate whether extending fusion to L4 is imperative in the surgical treatment of pediatric L5-S1 spondylolisthesis. This retrospective analysis encompassed 68 pediatric cases of dysplastic L5-S1 spondylolisthesis who underwent posterior lumbar interbody fusion surgery at two hospitals. Patients were categorized into two groups based on the upper instrumented vertebra (group L4 and group L5). Data were collected from medical records and radiological images obtained preoperatively and at last follow-up. Radiographic parameters including slip percentage (SP), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), Spinal Deformity Study Group dysplastic lumbosacral angle (SDSG-LSA), pelvic tilt (PT), Dubousset's lumbosacral angle (Dub-LSA), sacral slope (SS), and severity index (SI) were measured. Surgery-related data and complication data were also collected. The incidence rates of complications were compared, including those of neurological deficit, adjacent-segment instability (ASI), and other complications. ASI was defined as progression of slippage > 3 mm or posterior opening > 5° in the adjacent segment. Clinical outcomes were assessed with the numeric rating scale (NRS) and the Oswestry Disability Index (ODI) scores. The follow-up period for all patients lasted a minimum of 2 years. Among all 68 patients, group L4 consisted of 15 patients and group L5 comprised 53 patients. The patients included in both groups had comparable baseline demographic characteristics and radiographic parameters. Postoperative SP and SDSG-LSA were significantly lower in group L5 (p < 0.05). No other postoperative radiographic differences were observed between groups. One patient in group L4 and 3 patients in group L5 experienced transient neurological deficits (p > 0.05). There were 13 cases of ASI in group L5 compared with none in group L4 (24.5% vs 0%, p > 0.05). Of the 13 patients with ASI, 4 underwent revision surgery due to L4-5 level instability and clinical symptoms. The remaining individuals exhibited no symptoms, and regular annual follow-up assessments are being conducted for all patients. The NRS and ODI scores at final follow-up did not exhibit any significant differences between the two groups. Fusion to L5 could achieve comparable satisfactory results to fixation to L4, albeit with increased likelihood of ASI. Extension of fusion to L4 may not be necessary for most patients with pediatric L5-S1 spondylolisthesis.

L4/5 Disc Herniation: Not Unusually Accompanied with L5/S1 Low-Grade Spondylolytic Spondylolisthesis.

Isthmic spondylolisthesis (IS) is distinguished by a congenital defect or acquired fracture of the pars interarticularis. Numerous studies on L5 low-grade IS have been carried out; however, there is a paucity of data regarding the condition of L5 IS concomitant with L4/5 disc herniation. This study aimed to identify the incidence rate and to illustrate the possible risk factors for L4/5 disc herniation in L5 low-grade IS patients. A total of 268 consecutive patients diagnosed as L5/S1 low-grade IS between May 2017 and May 2022 were retrospectively enrolled in this study. Depending on the presence of L4/5 disc herniation or not, patients were divided into an L4/5 disc herniation group (L4/5 DH) and an L4/5 non-disc herniation group (L4/5 non-DH). Radiographic parameters were measured, and the ratios of L4-S1 segmental lordosis (SL) to lumbar lordosis (LDI), L4 inferior endplate (IEP) to L5 superior endplate (SEP) (L4 IEP/L5 SEP), and L5 IEP to S1 SEP (L5 IEP/S1 SEP) were compared between groups. The Pfirrmann grade of the L4/5 disc and the L5/S1 disc, and Roussouly classifications of each patient were also recorded. Univariate analysis (including independent-samples t-test and χ2 -test) and multiple logistic regression analysis were performed to analyze the data. There were 40 patients (14.9%) in the L4/5 DH group. The Roussouly classification differed significantly between groups. As demonstrated by the Pfirrmann grade, the L4/5 DH group showed more advanced disc degeneration at L4/5 than the L4/5 non-DH group. In contrast to the L4/5 non-DH group, the L4/5 DH group had a significantly larger L4 IEP, L4 IEP/L5 SEP, S1 SEP, and LDI while smaller L4/5 disc angle, L4/5 disc height, slip percentage, lumbar lordosis, and sacral slope. Multivariate logistic regression analysis revealed that higher L4/5 disc Pfirrmann grade (p = 0.004), decreased L4/5 disc height (p < 0.001), and lower L5 slip percentage (p = 0.022) were significantly associated with the occurrence of L4/5 DH. L4/5 disc herniation is not unusually accompanied by L5/S1 low-grade IS. Advanced L4/5 disc degeneration, decreased L4/5 disc height, and lower L5 slip percentage might be significantly associated with L4/5 disc herniation.

Clinical value of flexion-extension radiographs with bracket support for lumbar stability assessment.

This study proposes a novel standardized technique to evaluate lumbar stability in lumbar lateral flexion-extension radiographs and determine whether the most reliable intraoperative reference level of extension can be attained. A total of 104 patients undergoing surgical treatment for lumbar degenerative disease were included in the study. Radiographs in the conventional extension position (CE) and the extension position with bracket support (CEB) and intraoperative prone fluoroscopic radiographs of patients were included in this study. The slip angle (SA) and slip percentage (SP) were compared for these three radiographic methods. Furthermore, the correlation of differences in the SA and SP were examined among different spinal segments. Among 104 patients (mean age 58 years, 54% women) with a total of 147 operated segments examined, the average SA (10.65°±3.65°) and SP (12.18%±4.91%) with bracket support and SA (10.62°±3.67°) and SP (12.19%±4.90%) during intraoperative muscle relaxation were not significantly different (P=0.54; 0.91). However, the SA and SP in the CEB and intraoperative muscle relaxation conditions were significantly increased compared with the SA (6.46°±3.23°) and SP (7.87%±4.26%) obtained in the CE condition (all P<0.001). Both surgeons demonstrated high reliability, with intraclass correlation coefficient values ranging from 0.8 to 1.0 (P<0.001) for SP and SA measurements. CE radiographs underestimate the degree of displacement of lumbar instability. The CEB position reduces patient back pain and increases the feeling of safety, leading to a greater level of extension. This outcome aligns with the intraoperative muscle relaxation findings.

تأثير زاوية الشفرة والسرعة الأمامية على أداء جزازة العشب MURRAY-15.5hp

A field experiment was conducted to design, implement, and test the effect of blade angle represented by cutting angle and foreword speed on the performance of a MURRAY-15.5hp lawn mower machine. Three types of blades with cutting angles of 20o, 25o, and a straight angle were used, as well as three forward speeds of 2.99, 4.32, and 5.60 km h-1. The slippage percentage, field productivity, material quantity and total costs were studied. The results indicated the following: decreasing the cutting angle from 25o to 20o and then to a straight angle considerably decreases the slippage percentage and a significant decrease in total costs .Also, a significant increase in the field and Material productivity. Increasing the foreword speed resulted in a significant increase in the slippage percentage and a significant increase in in the field and material productivity, and decrease in the total costs. The interaction between the straight blade type and the forward speed 2.99 km h-1 led to the lowest slippage at 8.34%, while the interaction between the straight blade type and forward speed 5.60 km h-1 resulted in the lowest total costs amounted to 12036 dinars*hectare-1 and the highest field productivity 0.360 ha h-1 while the highest material productivity was 121.25 kg h-1.

Radiographic predictors of reaching minimal clinically important difference following lumbar fusion surgery in patients with degenerative lumbar spondylolisthesis.

The present study aimed to (1) compare sagittal alignment between patients with degenerative lumbar spondylolisthesis (DLS) who reached or missed the minimal clinically important difference (MCID) for clinical outcomes following lumbar fusion surgery (LFS) and (2) identify radiographic predictors associated with MCID achievement in DLS patients. A total of 91 single-level DLS patients who underwent LFS and had a minimum of 1-year follow-up were enrolled in this study. The assessed radiographic parameters included thoracic kyphosis, lumbar lordosis (LL), segmental lumbar lordosis (SLL), slip percentage, sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), and sagittal vertical axis. Changes in radiographic parameters were determined by subtracting the preoperative value from the final follow-up measurement. Clinical outcomes were assessed using the Oswestry Disability Index (ODI) and the visual analog scale (VAS) for both back and leg pain. MCID values were set at 10 points for ODI, 2.1 points for VAS back pain, and 2.8 points for VAS leg pain. Patients were assigned to the reached MCID (rMCID) and missed MCID (mMCID) groups based on the postoperative (post-op) recovery of clinical outcomes. At the last follow-up, 68.1% (62/91), 72.5% (66/91), and 76.9% (70/91) of patients reached MCID for ODI, VAS back pain, and VAS leg pain, respectively. Concerning ODI, the rMCID group exhibited higher post-op LL (47.93° vs. 42.95°, P = 0.044), higher post-op SLL (17.08° vs. 14.41°, P = 0.032), higher post-op SS (34.46° vs. 30.63°, P = 0.027), higher ∆LL (5.90° vs. 2.44°, P = 0.017), higher ∆SLL (4.63° vs. - 1.03°, P < 0.001), higher ∆SS (4.76° vs. 1.23°, P = 0.002), lower post-op PT/PI (36.95% vs. 42.01%, P = 0.049), lower ∆PT (- 3.71° vs. 1.05°, P < 0.001), lower ∆PT/PI (- 7.45% vs. 1.97%, P < 0.001), and lower ∆PI-LL (- 5.43° vs. - 3.71°, P = 0.011) than the mMCID group. Regarding VAS back pain, the rMCID group showed higher post-op SLL (17.06° vs. 14.05°, P = 0.021), higher post-op SS (34.34° vs. 30.33°, P = 0.027), higher ∆SLL (3.93° vs. - 0.09°, P < 0.001), and lower ∆PT (- 2.91° vs. - 0.30°, P = 0.039) than the mMCID group. For VAS leg pain, higher ∆SLL (3.55° vs. 0.41°, P = 0.003) was observed in the rMCID group than in the mMCID group. Multivariate logistic regression analysis revealed that higher ∆SLL, higher ∆SS, and higher post-op SS were independent predictors for the achievement of MCID in patients with DLS. DLS patients who reached MCID following LFS demonstrated improved post-op spinopelvic alignment. Higher ∆SLL, higher ∆SS, and higher post-op SS were the critical parameters associated with MCID achievement in patients with DLS.

The Effect of Tillage Depth on some Machinery Unit Performance Indicators, Soil Physical Properties and Germination Percentage using Combine Equipment

A field experiment was conducted to determine the effect of the locally manufactured agricultural machine on some performance indicators of the mechanical unit and some physical soil properties in a silty clay loamy soil texture in one of the fields of the College of Agricultural Engineering Sciences / University of Baghdad/Al-Jadriya for the spring season of 2023. The experiment used a tractor type (MF-650), and the study included one factor, the plowing depths, with three levels: 15, 20, and 25 cm. The study examined some performance indicators of the mechanical unit, including: pulling force, fuel consumption, slippage percentage, soil bulk density, soil moisture content, total soil porosity, germination percentage, number of dropped seeds, and the percentage of broken or damaged dropped seeds. The experimental design used was a randomized complete block design (RCBD) with three replications, and the least significant difference (LSD) test was used at a significance level of 0.05 to compare the means of the variables. The results indicated that increasing the plowing depth from 15 to 20 and then to 25 cm led to a significant increase in the percentage of slippage, which increased from 4.37% to 7.37% and then to 14.33%, respectively. The pulling force also increased from 5.33 to 9.67 and then to 14.44 kilonewtons, respectively. The fuel consumption increased from 43.32 to 56.84 and then to 66.67 liters per hectare, respectively. The bulk density of the soil increased from 1.06 to 1.08 and then to 1.15 micrograms per cubic meter, respectively. There was an increase in soil moisture content from 14.11 to 15.19 and then to 16.63%, respectively. There was no significant effect of plowing depth on the percentage of germination, the number of dropped seeds, and the percentage of broken seeds.

Assessment of the Performance Efficiency of Eight-Purpose Compound Equipment in One

A field experiment was conducted to assess the performance of a locally developed and assembled eight-purpose compound equipment and determine its effect on some physical soil properties in a silty clay loam soil in one of the fields of the College of Agricultural Engineering Sciences / University of Baghdad / Jadriyah for the growing season 2022-2023. The experiment used two tractors, the (MF-650) MASSEY FERGUSON and the (MF-5640) MASSEY FERGUSON. The study included two factors: the first factor had three seed rates (3, 4, and 5 kg/donum), and the second factor had three tillage depths (15, 20, and 25 cm). Some performance indicators of the machinery unit were studied, including pulling force, fuel consumption, slippage percentage, and bulk density of the soil. The experiment was conducted using a randomized complete block design (RCBD) with split-plot arrangement and three replications. Seed rates allocated to the main plot, while the tillage depth treatments allocated to the sub-plot. The least significant difference (LSD) at a significance level of 0.05 was used to compare the means of the variables. The results showed significant differences in the performance indicators of the machinery unit due to the tillage depth and seed rate. The depth of 15 cm showed the lowest pulling force, which was 5 kilo Newtons, the lowest slippage percentage of 4.26%, and the lowest fuel consumption of 42.58 L ha-1. The results also confirmed the absence of significant differences in the performance indicators of the machinery unit due to the seed rate and the absence of significant differences in the performance indicators due to the interaction between tillage depth and seed rate.

Two-year results of single-level fixation with lateral mass screws for cervical degenerative spondylolisthesis: patient series.

In surgery for cervical spondylotic myelopathy (CSM) with spondylolisthesis, there is no consensus on the correction and fixation for spondylolisthesis. The authors retrospectively studied whether the correction of single-level fixation with lateral mass screws (LMSs) could be maintained. The records of patients with CSM with spondylolisthesis who had been treated with posterior decompression and single-level fusion with LMSs from 2017 to 2021 were retrospectively reviewed. Radiographic measurements included cervical parameters such as C2-7 lordosis, T1 slope, and the degree of spondylolisthesis (percent slippage) before surgery, immediately after surgery, and at the final observation. Ten cases (mean age 72.8 ± 7.8 years) were included in the final analysis, and four cases (40%) were on hemodialysis. The median observation period was 26.5 months (interquartile range, 12-35.75). The mean percent slippage was 16.8% ± 4.7% before surgery, 5.3% ± 4.0% immediately after surgery, and 6.5% ± 4.7% at the final observation. Spearman's rank correlation showed a moderate correlation between preoperative slippage magnitude and correction loss (r = 0.659; p = 0.038). Other parameters showed no correlation with correction loss. For CSM with spondylolisthesis, single-level fixation with LMSs achieved and maintained successful correction in the 2-year observation.

Saving Stabilizing Structure Treatment With Bilateral-Contralateral Decompression for Spinal Stenosis in Degenerative Spondylolisthesis Using Unilateral Biportal Endoscopy.

This study aimed to evaluate the treatment of spinal stenosis with spondylolisthesis using bilateral-contralateral unilateral biportal endoscopic (UBE) decompression to minimize facet joint damage. We retrospectively evaluated 42 patients with grade 1 spondylolisthesis who underwent bilateral-contralateral UBE decompression between July 2018 and September 2019. To identify segmental instability, static and dynamic images from preoperative and postoperative procedures and final follow-up radiographs were reviewed. Lateral radiograph slippage ratio, sagittal motion, and facet joint preservation were evaluated. Clinical assessments were conducted using the visual analogue scale (VAS), Oswestry Disability Index (ODI), and modified MacNab criteria. The average final follow-up period was 26.5 ± 1.3 months. The average preoperative slip percentage was 15.70% ± 5.25%, which worsened to 18.80% ± 5.41% at the final follow-up (p < 0.005). The facet joint preservation rate was 95.6% ± 4.1% on the contralateral side. Improvements in the VAS scores (leg pain: from 7.9 ± 2.2 to 3.1 ± 0.7; p < 0.005; back pain: from 7.2 ± 3.0 to 2.8 ± 1.0; p < 0.005) were observed at the final follow-up. The mean preoperative ODI was 26.19 ± 3.42, which improved to 9.6 ± 1.0 (p < 0.005). Thirteen patients exhibited delayed focal segmental instability following decompression. Despite the absence of symptoms or improvement with conservative treatment in the majority of patients with delayed instability, two patients required fusion surgery to address the instability. Additionally, 2 patients developed facet synovial cysts, while 2 experienced spinous process fractures. Bilateral decompression with a contralateral UBE approach could be an effective and alternative treatment method to reduce instability in spinal stenosis with grade 1 spondylolisthesis.

Study Of Evaluating The Performance And Productivity Of A Potato Digger

A field experiment was conducted in one of the fields of the Technical Institute in Shatrah in 2022 to study the evaluation performance and productivity of the locally modified chain carrier potato. Slippage percentage, fuel consumption and machine productivity were studied in this research. The included use of three factors: the forward speed of the tractor at three levels, where it was (2.50,3.20 and 4.00 km / h) respectively, and the second factor was the speed of the chain conveyor at two levels, 43 and 38 m /min, and the third factor is a type of chain conveyor with two levels of iron bars and cloth -coated bars. A complete random design with three replications was used in the research. The results were statistically analyzed, and the averages were tested in a way with the least significant difference at the probability level of 0.05. The results showed that the tractor speed of 2.50 km/hr, recording the lowest slippage percentage, reached 4.20%, while the speed of 4.00 km/hr had the lowest fuel consumption and the highest productivity digger. Keywords: Slippage percentage, fuel consumption, speed chain conveyor type.

One-Bone Forearm Procedure for Severe Recalcitrant Forearm Deformities in Masada IIb Hereditary Multiple Exostoses.

Hereditary multiple exostoses (HME) Masada IIB has traditionally been treated by gradual ulnar lengthening with questionable efficacy in reducing the dislocated head. One-bone forearm (OBF) has been used as a reconstructive procedure in forearm deformities with very scarce literature for HME. The study aims to report short-term results of OBF as a definitive procedure for severe forearm deformities in Masada IIB patients with respect to clinical and radiological parameters. Four patients with HME Masada IIb were included in this retrospective study. All patients complained of forearm and wrist deformity with an abnormal bony protrusion restricting elbow motion. Indications for OBF were ulnar shortening > 3cm, dysplastic proximal radius with convex radial head and restricted prono-supination. All patients were examined pre-operatively and post-operatively clinically and radiographically using the Peterson's outcome score. The average age was 13 years (12-14years). Pre-operative ulnar shortening, carpal slip percentage, and radial articular angle was 3.4 cm, 79.5%, and 47.5°, respectively. All radial heads were dislocated with convex articular surface restricting elbow extension and forearm prono-supination. At the latest follow-up, the mean elbow flexion was 110° with forearm in 10° supination. The mean carpal slip percentage, radial articular angle, and Peterson functional grade was 15%, 22.5°, and 8 points, respectively. The mean follow-up period was 30.25 months with no recurrence. We recommend one bone forearm as a definitive procedure in HME Masada IIB patients with severe forearm deformities with ulnar shortening > 3cm and dysplastic proximal radius with a dislocated radial head, for faster return to function.