Lordosis In Patients Research Articles

Is multilevel MIS-TLIF with bilateral facetectomy a lordosing procedure? A retrospective cohort of 3-level MIS-TLIF.

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a common surgery that has been extensively reported. However, publications on 3-level MIS-TLIF are sparse, and the effects of multilevel MIS-TLIF on sagittal balance remain controversial. This study aimed to analyze the outcomes and variables involved in the correction of sagittal imbalance by multilevel MIS-TLIF. Consecutive patients who underwent 3-level MIS-TLIF were retrospectively analyzed. Demographics and clinical outcomes were evaluated. Standard radiological and spinopelvic parameters were measured pre- and postoperatively, and at the last follow-up. A linear regression model was used to examine the correlation between preoperative segmental lordosis (SL) and the degree of sagittal correction. An optimal cutoff of preoperative SL to predict the change in sagittal correction was determined by receiver operating characteristic (ROC) analysis. Forty-seven patients (mean follow-up 24.63 ± 12.69 months) were included. Postoperatively, all patients showed clinical improvements, demonstrated by the Oswestry Disability Index and visual analog scale. The overall SL at the last follow-up was slightly nonsignificantly increased (1.23°, p = 0.267), while the other spinopelvic parameters, including lumbar lordosis (p = 0.008), sacral slope (p < 0.001), pelvic tilt (p = 0.002), and pelvic incidence-lumbar lordosis mismatch (p = 0.006), all improved significantly compared with preoperatively. The preoperative SL was negatively correlated with the change in SL at the last follow-up (r2 = 0.2591, p = 0.0003), and the cutoff value was 26.89° (area under the ROC curve = 0.7836, p = 0.0087). The 24 patients who had a less lordotic lumbar spine (i.e., preoperative SL ≤ 27°) demonstrated significant improvement in spinopelvic parameters, whereas the other 23 patients (SL > 27°) had a slight, insignificant decrease of spinopelvic parameters. Multilevel MIS-TLIF improved sagittal balance and SL with satisfactory patient-reported clinical outcomes at 2 years postoperatively. Multilevel MIS-TLIF was more effective in increasing lordosis in patients whose lumbar spine had a smaller preoperative lordotic curve (SL ≤ 27°).

Predicting Immediate Lordosis Restoration After Anterior Lumbar Interbody Fusion and the Effect of Posterior Column Osteotomies

Anterior lumbar interbody fusion (ALIF) can be combined with posterior column osteotomies (PCOs) to maximize lordotic correction. This study compares radiographic changes in regional and segmental lordosis in patients undergoing ALIF with and without PCOs. Patients >18 years old who underwent ALIF at 1 or 2 segments at a single institution (January 2014-July 2020) were included. Preoperative and postoperative radiographic parameters were determined, and a propensity-matched analysis was performed. Ninety-nine patients (53 [54%] men) underwent ALIF at 129 levels (mean [SD], 1.3 [0.46] levels; median [range] age, 61 [32-83] years). PCOs were performed in 13 (13%) patients at 19 (15%) segments. PCOs included 13 Schwab grade 1 and 6 grade 2 osteotomies. All measures, including lumbar lordosis, segmental lordosis, disc angle, and neural foramen height, increased significantly after surgery (p≤0.003). In the propensity-matched analysis, PCO was associated with greater increases in lumbar lordosis (14.9° vs. 8.2°, p=0.02), segmental lordosis (14.0° vs. 9.6°, p=0.03), and disc angle (15.0° vs. 10.2°, p=0.046). The change in disc angle more closely approximated the inherent lordosis of the cage when PCO was performed (94% vs. 62%, p=0.004). Performing PCOs and ALIFs significantly increased the radiographic correction of overall and segmental lordosis in the selected patient cohort. The disc angle achieved with ALIF without PCOs was approximately 60% of the cage lordosis. The addition of PCO allowed for greater segmental compression, enabling the disc angle to reach nearly 100% of the inherent interbody cage lordosis.

Impact of Supine versus Prone Positioning on Segmental Lumbar Lordosis in Patients Undergoing ALIF Followed by PSF: A Comparative Study.

Background: Anterior lumbar interbody fusion (ALIF) and posterior spinal fusion (PSF) play pivotal roles in restoring lumbar lordosis in spinal surgery. There is an ongoing debate between combined single-position surgery and traditional prone-position PSF for optimizing segmental lumbar lordosis. Methods: This retrospective study analyzed 59 patients who underwent ALIF in the supine position followed by PSF in the prone position at a single institution. Cobb angles were measured preoperatively, post-ALIF, and post-PSF using X-ray imaging. One-way repeated measures ANOVA and post-hoc analyses with Bonferroni adjustment were employed to compare mean Cobb angles at different time points. Cohen's d effect sizes were calculated to assess the magnitude of changes. Sample size calculations were performed to ensure statistical power. Results: The mean segmental Cobb angle significantly increased from preoperative (32.2 ± 13.8 degrees) to post-ALIF (42.2 ± 14.3 degrees, Cohen's d: -0.71, p < 0.0001) and post-PSF (43.6 ± 14.6 degrees, Cohen's d: -0.80, p < 0.0001). There was no significant difference between Cobb angles after ALIF and after PSF (Cohen's d: -0.10, p = 0.14). The findings remained consistent when Cobb angles were analyzed separately for single-screw and double-screw ALIF constructs. Conclusions: Both supine ALIF and prone PSF significantly increased segmental lumbar lordosis compared to preoperative measurements. The negligible difference between post-ALIF and post-PSF lordosis suggests that supine ALIF followed by prone PSF can be an effective approach, providing flexibility in surgical positioning without compromising lordosis improvement.

Changes in canal diameter and cervical lordosis in patients who underwent en-bloc laminoplasty for the treatment of cervical spinal stenosis

Objective: Cervical spinal canal-expanding laminoplasty has been recognized as an alternative to cervical laminectomy, especially in multilevel cervical myelopathy due to spinal stenosis. This study aimed to determine the effects of En-block laminoplasty on cervical sagittal balance, cervical spine biomechanics and whether it is sufficient to preserve cervical canal diameter and lordosis and whether it causes additional lordosis or kyphosis in cases of cervical narrow spinal canal. Methods: Thirty-eight cervical narrow canal patients operated on between 2008 and 2020 were retrospectively evaluated and the results of 24 laminoplasty patients were evaluated. Spinal tomography results for the evaluation of canal diameter changes and X-ray results for cervical sagittal balance evaluation were compared with each other in the early postoperative period and 3 years later. For cervical lordosis assessment, Cobb and C2-C7sagital vertical axis measurements were performed using the PACS system. Results: Fifteen patients were male and 9 were female. The mean age was 65.55±11.56 years (min-max: 58-84) and the mean follow-up period was three years. Two patients had one level stenosis, 4 had two levels, 7 had three levels, and 11 had four or more levels. Radiculopathy was present in 17 patients (71.8%) and myelopathy in 7 patients (29.1%). There was no statistically significant difference in the frequency of myelopathy/radiculopathy between genders. When all distances were considered, no statistical difference was observed in the early postoperative period (median ten days) and late postoperative period (median 3 years) in terms of canal diameters. No measurement value could be obtained for any level diagnosed as restenosis or requiring reoperation. Loss of lordosis was measured in only one patient. Otherwise, lordosis was preserved in all cases at late conversion. Conclusions: The results of our study showed that en-block laminoplasty after the cervical narrow spinal canal was sufficient to maintain the cervical canal diameter in the long term with appropriate patient and surgical technique.

Comparative characteristics of cervical sagittal balance parameters and atlantoaxial instability criteria in normal and Down syndrome children

BACKGROUND: Sagittal balance of the spine has received considerable development in recent years. However, most studies focused on the assessment of vertebral–pelvic parameters. The cervical spine has long received insufficient attention from researchers, but this trend has been changing. The study of cervical sagittal balance in children with Down syndrome is beneficial in approaching the preconditions of atlantoaxial instability. AIM: To perform a comparative analysis of cervical sagittal balance parameters and atlantoaxial instability criteria in normal and Down syndrome children. MATERIALS AND METHODS: Radiographs of the cervical spine in the neutral position in lateral projection and postural radiographs of 110 pediatric patients were analyzed retrospectively. The patients were divided into two groups: group 1 (normal), 60 children aged 4–17 years without spinal pathology, and group 2 (Down syndrome), 50 children aged 4–17 years with Down syndrome. The parameters of cervical sagittal balance (Oc-C2, Oc-C7, C1-C2, C2-C7, C2-C7H, C7S, Th1S, TIA, NT) and criteria for atlantoaxial instability (Nakamura angle, ADI, SAC-C1, SAC-C1/SAC-C4) were obtained, and data was statistically analyzed. RESULTS: Significant differences in the parameters C7S, Th1S, and TIA increased in children with Down syndrome. These parameters are involved in cervical lordosis; however, no significant differences in cervical lordosis angles were found. Furthermore, significant differences were noted in the criteria of atlantoaxial instability ADI, SAC-C1, and SAC-C1/SAC-C4 toward their decreasing in children with Down syndrome. CONCLUSION: In patients with Down syndrome, the indices of cervical lordosis are statistically greater than those in normal children. Moreover, the parameters of cervical lordosis in patients with Down syndrome do not differ from those in normal children. Therefore, during flexion, subcompensation of the cervical spine is observed in children with Down syndrome. Given the statistically smaller indicators ADI, SAC-C1, SAC-C1/SAC-C4, low neck muscle tone, and ligamentous hypermobility, these abnormalities can be considered as congenital predisposition factors for atlantoaxial instability in children with Down syndrome.

Modified S1 Pedicle Subtraction Osteotomy.

Surgical technique video. To report a surgical technique to revise patients with previous fusions at L4-S1 leading to an iatrogenic flat back and sagittal imbalance using L5-S1 transforaminal interbody fusion combined with a small S1 corner osteotomy. This is a case of a woman (51 y old) with a history of multiple lumbar surgeries, severe back pain, sagittal imbalance, and loss of lordosis. We describe a feasible revision technique in a complex patient with the goal of attaining optimal distribution of lumbar lordosis and sagittal balance through a modified S1 pedicle subtraction osteotomy, and the use of an interbody cage to enhance the fusion rate and facilitate closure of the 3-column osteotomy. The preoperative patient lordosis angle of 31 degrees at L1-L4 and 16 degrees at L4-S1 became 12 degrees at L1-L4 and 44 degrees at L4-S1 postoperatively. The combination of L5-S1 transforaminal interbody fusion and S1 corner osteotomy is a feasible technique for the restoration of lumbar lordosis in patients with previous fusion and consequent loss of lordosis.

Analysis of Spinopelvic Parameters and Lumbar Lordosis in Patients with Transitional Lumbosacral Vertebrae, with Special Reference to Sacralization and Lumbarization

BackgroundTransitional lumbosacral vertebra (TLSV) presents in two forms based on its origin: sacralization and lumbarization. These patients have two options for sacral endplates (upper and lower) and consequently, two sets of values for spinopelvic parameters and lumbar lordosis (LL). This study aimed to evaluate these parameters in asymptomatic patients with sacralization and lumbarization and compare them with each other and normative values. MethodsSpinopelvic parameters and LL according to upper and lower endplate were measured using abdominal computed tomography in 1420 asymptomatic patients, of which 108 had TLSV. These parameters were compared among patients with lumbarization and sacralization and with normal controls. In addition, correlations between the upper and lower endplate parameters were determined. ResultsAs compared to the control group, upper endplate measurements yielded lower spinopelvic parameters and LL values while lower endplate values yielded higher values. While these values were significantly different from normative values, these parameters were similar in both lumbarization and sacralization groups. Furthermore, most spinopelvic parameters of both upper and lower endplates were strongly correlated, and the differences between the upper and lower PI and LL values are relatively constant (27° and 14°, respectively. ConclusionUpper and lower endplate parameters are comparable in patients with sacralization and lumbarization; therefore, the average spatial position of a sacralized L5 and a lumbarized S1 within the pelvis is similar and either parameter can be used for radiological measurements. Further studies with symptomatic patients are warranted to confirm these results.

Relationship between Cervical Instability in the Course of Rheumatoid Arthritis and Pelvic Parameters of Sagittal Balance.

The aim of the study is to search for a relationship between cervical instability in the course of rheumatoid arthritis (RA) and pelvic parameters of sagittal balance and lumbar lordosis (LL). The study included 47 patients with rheumatoid arthritis with instability of the cervical segment, who were referred for a consultation to assess indications for surgical treatment. The patients underwent a radiological functional examination of the cervical region and postural examination of the entire spine. The basic parameters of the lumbar section and pelvis of these patients were compared with the population values. Then, using statistical methods, the correlation between radiological parameters of various types of instability and lumbar lordosis (LL), pelvic parameters (PI, SS, PT), as well as the patient's age and duration of the disease was assessed. A statistical correlation was found between the instability in the cervical spine C2-C3 level and the value of the PT and PI angles. A statistically significant correlation was discovered between C1-C2 instability and younger patient age. There was no significant difference in the values of the pelvic parameters and lumbar lordosis in patients with rheumatoid arthritis compared to the population values. Preliminary results suggest that there is a relationship between selected pelvic parameters and the development of instability in patients with rheumatoid arthritis. This may be important in planning treatment and assessing disease progression. Further studies on a larger group of patients are needed, as well as studies evaluating the correlation between other sagittal balance parameters and cervical instability in patients with RA.

Assessing Alignment Using GAP Score and Complications for Pedicle Subtraction Osteotomy Revision Surgeries for Sagittal Deformity in Previously Fused Spines Using a Satellite Rod Technique

Pedicle subtraction osteotomy (PSO) is a surgical technique to restore lumbar lordosis in patients with rigid sagittal deformity. Herein, we report on outcomes of a surgical technique utilizing a 4-rod PSO with satellite rods. A retrospective study was performed for a cohort of patients who underwent 4-rod PSO revision surgery for sagittal deformity. Procedures were performed by one surgeon at 2 different academic centers between 2004-2018. Alignment outcomes and complications specifically for revision surgeries in previously fused spines were assessed. 40 patients underwent PSO with the satellite rod technique (n= 29 at L3, 72.5%; n= 7 at L4, 17.5%). Mean PSO angle was 28.7 ± 7.6°. Two patients (5%) had rod fracture necessitating revision surgery at 32 and 34months. Three patients (7.5%) developed proximal junctional kyphosis (PJK), but none required revision. No patients developed pseudoarthrosis. Mean preoperative sagittal vertical axis (SVA) was 13.5 ± 7.3cm, which decreased to 4.8 ± 7.3cm (P= 0.002) postoperatively. Mean preoperative pelvic incidence-lumbar lordosis (PI-LL) mismatch improved from 35.9 ± 16.6° preoperatively to 11.8 ± 14.6° postoperatively (P < 0.001). Mean preoperative pelvic tilt (PT) improved from 34.7 ± 9.8° preoperatively to 30.1 ± 9.0° (P= 0.026) postoperatively. Mean global alignment and proportion (GAP) score improved from 10 ± 2 preoperatively to 8 ± 2 postoperatively (P < 0.001), which was still considered severely disproportioned. Rod failure rate after PSO with the 4-rod satellite configuration was low. SVA, PI-LL mismatch, and PT significantly improved for these previously-fused patients. Mean GAP score also improved, but was still considered severely disproportioned, likely due to the inability of PSO to correct low LL or PT in previously-fused spines.

Preservation of Cervical Lordosis in Patients with Multilevel Cervical Spondylosis: Implantation of Anatomical Cervical Cage

Preservation of Cervical Lordosis in Patients with Multilevel Cervical Spondylosis: Implantation of Anatomical Cervical Cage

Non-Surgical Management of Upper Cervical Instability via Improved Cervical Lordosis: A Case Series of Adult Patients

Injury to the head and neck resulting from whiplash trauma can result in upper cervical instability (UCIS), in which excessive movement at C1 on C2 is observed radiologically. In some cases of UCIS there is also a loss of normal cervical lordosis. We postulate that improvement or restoration of the normal mid to lower cervical lordosis in patients with UCIS can improve the biomechanical function of the upper cervical spine, and thus potentially improve symptoms and radiographic findings associated with UCIS. Nine patients with both radiographically confirmed UCIS and loss of cervical lordosis underwent a chiropractic treatment regimen directed primarily at the restoration of the normal cervical lordotic curve. In all nine cases, significant improvements in radiographic indicators of both cervical lordosis and UCIS were observed, along with symptomatic and functional improvement. Statistical analysis of the radiographic data revealed a significant correlation (R2 = 0.46, p = 0.04) between improved cervical lordosis and reduction in measurable instability, determined by C1 lateral mass overhang on C2 with lateral flexion. These observations suggest that enhancing cervical lordosis can contribute to improvement in signs and symptoms of upper cervical instability secondary to traumatic injury.

Comparison of Midline Splitting versus Unilateral Open Door Laminoplasty and Its Impact on Patient Outcomes.

Laminoplasty is a common and effective surgery for decompression of the spinal cord in multilevel cervical myelopathy. The midline splitting technique (MST) and the unilateral open door technique (UODT) are the two most commonly performed laminoplasty techniques with continuous debate on which is preferable. This study aimed to add light to the matter by comparing and exploring the possible causes of different outcomes. A total of 101 patients who underwent laminoplasty for degenerative cervical myelopathy were included in this study. Radiographic measurements including C2-7 Cobb angle, C2-7 range of motion (ROM), Pavlov ratio of the most compressed level, and canal area with diameter were compared. Modified Japanese Orthopedic Association (mJOA) score and complications including C5 palsy, axial neck pain, hinge fractures, and spacer displacement were also compared. Statistical analysis was performed using independent samples t-test, chi-square test, Fisher's exact test, and linear mixed model. C2-7 ROM, canal diameter, Pavlov ratio, and mJOA score did not demonstrate differences between the two techniques. The UODT group had greater postoperative canal expansion but had more loss of C2-7 lordosis than did the MST group. Of the complications, hinge fractures were more common in the UODT group, with more loss of C2-7 lordosis in patients with hinge fractures. On the other hand, spacer displacement occurred only in the MST group, with lesser canal expansion in patients with spacer displacement. The two laminoplasty techniques both demonstrated effectiveness in treating patients with multilevel cervical myelopathy. However, care should be given to avoid hinge fractures and spacer displacement since both can possibly lead to unfavorable outcomes.

The Reliability of the Projection Area Per Length Squared for Measuring Lumbar Lordosis on Lateral Radiographs: A Comparison with Cobb Method

Objective: The assessment of the degree of lumbar lordosis in patients with spinal disorders is essential to determine disease progression and the effectiveness of treatment. The aim of this study was to examine the reliability of the projection area per length squared (PAL) for measuring lumbar lordosis on lateral radiographs and to compare it with the Cobb method. Methods: Two independent investigators measured lumbar lordosis twice on 100 lateral radiographs using PAL and Cobb methods. Intra- and interobserver agreements of each radiological method were evaluated using intraclass correlation coefficients (ICC) and Bland–Altman plots. Correlations between the PAL estimations and Cobb angle measurements were tested using the Spearman rank correlation coefficient. Results: Intra- and interobserver agreements for PAL and Cobb methods were excellent with all ICC values&gt;0.976. The Bland–Altman plots indicated strong intra-observer and interobserver concordance in the measurement of the lumbar lordosis using the PAL method. A strong correlation was determined between the PAL and Cobb angle values in the first and second measurements (r=0.825; p&lt;0.001 and r=0.815; p&lt;0.001, respectively). Conclusion: The PAL technique is easy to apply on digital images and provides quantitative information independent of the vertebral surface pathologies of the end vertebrae. It could be used as an alternative and potent diagnostic criterion for evaluating lumbar lordosis.

Radiographic Outcomes Following ACDF With Hyperlordotic Implants to Achieve Cervical Anterior Column Realignment

Degenerative disc disease and progressive sagittal malalignment can both contribute to degenerative cervical myelopathy and radiculopathy. For patients with symptoms refractory to conservative management, anterior cervical discectomy and fusion (ACDF) is a thoroughly vetted intervention shown to improve pain and disability measures. Hyperlordotic implants can also help restore cervical sagittal balance through anterior column realignment (ACR). A consecutive bi-institutional series of patients who underwent ACDF with hyperlordotic polyetheretherketone (PEEK) implants between 2014 and 2016 was reviewed. All included patients underwent ACDF between C3 and C7 inclusive of a hyperlordotic PEEK cervical implant (>10° lordosis), and had ≥12 months of radiographic follow-up. Lateral radiographs were analyzed to compare pre- and postoperative cervical parameters. Forty-six patients were included (mean age, 58.0 years; male, 35%). Mean body mass index was 28.3kg/m2, and mean radiographic follow-up 14.4 months. Overall, cervical lordosis increased from -7.8° preoperatively to-14.8° postoperatively and to -15.7° at last follow-up (P<0.001). Additionally, the mean segmental lordosis of ACR levels treated increased from -0.2° preoperatively to -4.8° postoperatively (P < 0.001), but no significant change was observed at last follow-up. Lastly, improvement in segmental lordosis was seen at both postoperative time points at the C3-C4 (P= 0.002 and P= 0.005, respectively), C4-C5 (P < 0.001 and P < 0.001, respectively), and C5-C6 levels (P < 0.001 and P < 0.001, respectively). Our study demonstrates that hyperlordotic PEEK implants used for ACR effectively contribute to restoration of cervical lordosis in patients undergoing ACDF, potentially reducing the need for additional posterior surgery.

Postoperative spinal alignment comparison of lateral versus supine patient position L5-S1 anterior lumbar interbody fusion.

Over the past decade, alternative patient positions for the treatment of the anterior lumbar spine have been explored in an effort to maximize the benefits of direct anterior column access while minimizing the inefficiencies of single or multiple intraoperative patient repositionings. The lateral technique allows for access from L1 to L5 through a retroperitoneal, muscle-splitting, transpsoas approach with placement of a large intervertebral spacer than can reliably improve segmental lordosis, though its inability to be used at L5-S1 limits its overall adoption, as L5-S1 is one of the most common levels treated and where high levels of lordosis are optimal. Recent developments in instrumentation and techniques for lateral-position treatment of the L5-S1 level with a modified anterior lumbar interbody fusion (ALIF) approach have expanded the lateral position to L5-S1, though the positional effect on L5-S1 lordosis is heretofore unreported. The purpose of this study was to compare local and regional alignment differences between ALIFs performed with the patient in the lateral (L-ALIF) versus supine position (S-ALIF). Retrospective, multi-center data and radiographs were collected from 476 consecutive patients who underwent L5-S1 L-ALIF (n = 316) or S-ALIF (n = 160) for degenerative lumbar conditions. Patients treated at L4-5 and above with other single-position interbody fusion and posterior fixation techniques were included in the analysis. Baseline patient characteristics were similar between the groups, though L-ALIF patients were slightly older (58 vs. 54years), with a greater preoperative mean L5-S1 disk height (7.8 vs. 5.8mm), and with less preoperative slip (6.6 vs. 8.5mm), respectively. 262 patients were treated with only L-ALIF or S-ALIF at L5-S1 while the remaining 214 patients were treated with either L-ALIF or S-ALIF at L5-S1 along with fusions at other thoracolumbar levels. Lumbar lordosis (LL), L5-S1 segmental lordosis, L5-S1 disk space height, and slip reduction in L5-S1 spondylolisthesis were measured on preoperative and postoperative lateral X-ray images. LL was only compared between single-level ALIFs, given the variability of other procedures performed at the levels above L5-S1. Mean pre- to postoperative L5-S1 segmental lordosis improved 39% (6.6°) and 31% (4.9°) in the L-ALIF and S-ALIF groups, respectively (p = 0.063). Mean L5-S1 disk height increased by 6.5mm (89%) in the L-ALIF and 6.4mm (110%) in the S-ALIF cohorts, (p = 0.650). Spondylolisthesis, in those patients with a preoperative slip, average reduction in the L-ALIF group was 1.5mm and 2.2mm in the S-ALIF group (p = 0.175). In patients treated only at L5-S1 with ALIF, mean segmental alignment improved significantly more in the L-ALIF compared to the S-ALIF cohort (7.8 vs. 5.4°, p = 0.035), while lumbar lordosis increased 4.1° and 3.6° in the respective groups (p = 0.648). Use of the lateral patient position for L5-S1 ALIF, compared to traditional supine L5-S1 ALIF, resulted in at least equivalent alignment and radiographic outcomes, with significantly greater improvement in segmental lordosis in patients treated only at L5-S1. These data, from the largest lateral ALIF dataset reported to date, suggest that-radiographically-the lateral patient position can be considered as an alternative to traditional ALIF positional techniques.

How Does Gravity Influence the Distribution of Lordosis in Patients With Sagittal Malalignment?

Retrospective cohort study. Compare the supine vs standing radiographs of patients with adult spinal deformity against ideals defined by healthy standing alignment. 56 patients with primary sagittal ASD (SRS-Schwab Type N) and 119 asymptomatic volunteers were included. Standing alignment of asymptomatic volunteers was used to calculate PI-based formulas for normative age-adjusted standing PI-LL, L4-S1, and L1-L4. These formulas were applied to the supine and standing alignment of ASD cohort. Analyses were repeated on a cohort of 25 patients with at least 5 degrees of lumbar flexibility (difference between supine and standing lordosis). The asymptomatic cohort yielded the following PI-based formulas: PI-LL = -38.3 + .41*PI + .21*Age, L4-S1 = 45.3-.18*Age, L1-L4 = -3 + .48*PI). PI-LL improved with supine positioning (mean 8.9 ± 18.7°, P < .001), though not enough to correct to age-matched norms (mean offset 12.2 ± 16.9°). Compared with mean normative alignment at L1-L4 (22.1 ± 6.2°), L1-L4 was flatter on standing (7.2 ± 17.0°, P < .001) and supine imaging (8.5 ± 15.0°, P < .001). L4-S1 lordosis of subjects with L1-S1 flexibility >5° corrected on supine imaging (33.9 ± 11.1°, P = 1.000), but L1-L4 did not (23.0 ± 6.2° norm vs 2.2 ± 14.4° standing, P < .001; vs 7.3 ± 12.9° supine, P < .001). When the effects of gravity are removed, the distal portion of the lumbar spine (i.e., below the apex of lordosis) corrects, suggesting that structural lumbar deformity is primarily proximal.

Contribution of Multilevel Transformainal Lumbar Interbody Fusion Surgery to Restoration of Lumbar Lordosis in Patients with Degenerative Spine: Comparison of Long and Short Level Fusion.

To investigate the effect of multilevel transforaminal lumbar interbody fusion (TLIF) procedures in lumbar degenerative spine conditions on the restoration of lumbar lordosis (LL) in patients with short- and long-level fusion, and to examine the associated radiological results. This retrospective study reviewed patients with degenerative spinal diseases who underwent lumbar fusion using a multilevel TLIF procedure. Patients with three or fewer segments involved in fusion were assigned to the shortlevel fusion group and those with more than three segments involved in fusion were assigned to the long-level fusion group. The anteroposterior and lateral spine radiographs of the patients were used to measure LL, distal lumbar lordosis and radiological parameters. The study included 47 patients who met the inclusion criteria, with a mean age of 60.4 ± 12.2 years. The mean follow-up time of our patients was 18.3 ± 11 months. Thirty-five (74.5%) patients were women and 12 (25.5%) were men. Overall, 12 patients underwent 3-level and 35 patients underwent 2-level TLIF. Long-level fusion was performed in 24 patients and short-level fusion was performed in 23 patients. Multilevel TLIF can be used to correct spinopelvic alignment when applied with the appropriate indications and techniques in patients with degenerative spinal disorders. Multilevel TLIF is associated with substantial improvements in LL, distal lumbar lordosis, and SVA (sagittal vertical axis). It also helps to correct the correlation between PI and LL.

Does change in focal lordosis after spinal fusion affect clinical outcomes in degenerative spondylolisthesis?

ABSTRACTStudy Design:Retrospective cohort study.Objective:The objective of this study is to determine the effect of focal lordosis and global alignment and proportion (GAP) scores on patient reported outcome measures (PROMs) after posterior lumbar fusion for patients with 1- or 2-level lumbar degenerative spondylolisthesis (DS).Summary of Background Data:In patients with DS, improvements in spinopelvic parameters are believed to improve clinical outcomes. However, the effect of changing focal lordosis in patients with 1-or 2-level degenerative lumbar spondylolisthesis is unclear.Materials and Methods:Postoperative spinopelvic parameters and perioperative focal lordosis changes were measured for 162 patients at a single academic center from January 2013 to December 2017. Patients were divided into three groups: >2° (lordotic group), between 2° and −2° (neutral group), and −2°° (kyphotic group). Patients were then reclassified based on GAP scores. Recovery ratios (RR) and the number of patients achieving the minimal clinically important difference (MCID) were calculated for PROMs. Standard descriptive statistics were reported for patient demographics and outcomes data. Multiple linear regression analysis controlled for confounders. Alpha was set at P < 0.05.Results:There was no significant association between change in focal lordosis and surgical complications including adjacent segment disease (P = 0.282), instrumentation failure (P = 0.196), pseudarthrosis (P = 0.623), or revision surgery (P = 0.424). In addition, the only PROM affected by change in focal lordosis was Mental Component Scores (ΔMCS-12) (lordotic = 2.5, neutral = 8.54, and kyphotic = 5.96, P = 0.017) and RR for MCS-12 (lordotic = 0.02, neutral = 0.14, kyphotic 0.10, P = 0.008). Linear regression analysis demonstrated focal lordosis was a predictor of decreased improvement in MCS-12 (β = −6.45 [−11.03- −1.83], P = 0.007). GAP scores suggested patients who were correctly proportioned had worse MCID compared to moderately disproportioned and severely disproportioned patients (P = 0.024).Conclusions:The change in focal lordosis not a significant predictor of change in PROMs for disability, pain, or physical function. Proportioned patients based on the GAP score had worse MCID for Oswestry Disability Index.Level of Evidence:III

Analyzing the Significance of T1 Slope minus Cervical Lordosis in Patients with Anterior Cervical Discectomy and Fusion Surgery.

ObjectiveAccurate measurement of T1 slope (a component of T1s minus cervical lordosis [CL]) is often constrained by anatomical limitations. In this situation, efforts should be made to find the exact meaning of T1s-CL and whether there are any alternatives to it. MethodsWe enrolled 117 patients who received two-level anterior cervical discectomy and fusion (ACDF). Occipital slope, C2 slope (C2s), C7 slope (C7s), T1, O-C2 angle (O-C2A), C2-7 angle (C2-7A), O-C7 angle (O-C7A), T1s-CL, C7-T1 angle (C7-T1A), and C2-7 sagittal vertical axis were measured. We determined 16° (T1s-CL) as the reference point for dividing subjects into the mismatch group and the balance group, and a comparative analysis was performed. ResultsThe mean value of C7-T1A was constantly maintained within 2.6° peri-operatively. In addition, C2s and T1s-CL showed the same absolute change (Δ|0.8|°). The mean values of T1s-CL of the mismatch and balance groups were 23.0° and 7.6°, respectively. The five factors with the largest differences between the two groups were as follows : C2s (Δ13.3°), T1s-CL (Δ15.4°), O-C2A (Δ8.7°), C2-7A (Δ14.7°), and segmental angle (Δ7.9°) before surgery. Only four factors showed statistically significant change between the two groups after ACDF : T1s-CL (Δ4.0° vs. Δ0.2°), C2s (Δ3.2° vs. Δ0.7°), O-C2A (Δ2.6° vs. Δ1.3°), C2-7A (Δ6.3° vs. Δ1.3°). A very strong correlation between T1s-CL and C2s was also found (r=|0.88–0.96|). ConclusionC2s itself may be the essential key to represent T1s-CL. The amounts and directions of change of these two factors (T1s-CL and C2s) were also almost identical. The above phenomenon was re-confirmed once again through the correlation analysis.

Lumbar lordosis in patients undergoing non-instrumented spinal stenosis

Objective: To study the behaviour of Lumbar Lordosis (LL) after non-instrumented decompression surgery in patients diagnosed with Lumbar Spinal Stenosis (LSS). Methods and materials: Retrospective analysis of patients undergoing non-lumbar instrumented decompression surgery for lumbar spine stenosis, operated on between January 2011 and December 2017. The variables collected were age, sex, affected segment, and presence or not of degenerative spondylolisthesis (ELS). The Lumbar Lordosis (LL) parameter was analysed using conventional radiology in standing position pre and postoperatively. Results: 64 patients were selected, 17 women and 47 men, with an average age of 68 (35-83). 65% stenosis was located in a single level, and 39.1% had degenerative ELS grade I. The average follow-up was 26 months (6m-104m). A preoperative LL angle of 43.2º (9.8º-70.8º) and 47º (8º-76º) were found at the postoperative follow-up, with an average difference of 3.8º (-15.7º-20.2º). 9.4% (6 patients) of degenerative ELS evolved to grade II, and 8 patients needed reoperation for different reasons. In patients with ELS, we found a greater increase in postoperative LL (5.59º) than in patients without ELS (2.61º) (p = 0.08). No statistically significant relationship was found between the behaviour of the LL with the number of decompressed levels (p = 0.43) and the need for reoperation (p = 0.26). Conclusions: According to our study, the technique of posterior decompression without instrumentation of the lumbar spine stenosis is not associated with a decrease of lumbar lordosis parameter. Conversely, there is a slight tendency for LL to increase in cases where a degenerative ELS is present.