Spinopelvic Relationship Research Articles

Assessment of spinopelvic relationship among Turkish orthopedic surgeons in total joint replacement: a survey

Assessment of spinopelvic relationship among Turkish orthopedic surgeons in total joint replacement: a survey

A multicentre prospective assessment of the utility of robotic assisted total hip arthroplasty with virtual range of motion on intraoperative implant positioning.

The growing adoption of robotic-assistance during total hip arthroplasty (THA) has provided novel means through which a patient's anatomy and dynamic spinopelvic relationship can be incorporated into surgical planning. However, the impact of enhanced technologies on intraoperative decision-making and changes to component positioning has not yet been described. A multicentre, prospective study included 105 patients (52% women) patients who underwent robotic-assisted THA with the integration of software that incorporates a patient's pelvic tilt (PT) and virtual range-of-motion (VROM) for impingement modeling. The primary outcome of the study was the percentage of patients who underwent changes to the preoperative plan for cup position after incorporating the data from the software. Utilising the intraoperative VROM information, the preoperative plan for cup position was changed from the default (40° inclination and 20° anteversion) in 82/105 (78%) cases. When stratifying by spinopelvic mobility, 64% were considered normal (change ⩾ 10° and ⩽30°), 27% were stiff (change < 10°), and 9% were hypermobile (change > 30°). For all cohorts, the majority of cases (78%) deviated from the 40° inclination and 20° version target. When evaluating the proportion of cases within the Lewinnek and Callanan safe zones based on spinopelvic mobility, 19% of cases within the normal group were planned outside of both zones compared to 39% of stiff cases and 10% of hypermobile cases. Utilising the latest version of robotic-assisted THA software, the preoperative plan for cup position was changed in the vast majority (78%) of patients, causing substantial deviations from traditional, generic cup targets.

An alternative method for measuring patient’s sagittal balance parameters in sitting and standing positions

Introduction The understanding of the biomechanics of movements in the spinopelvic segment plays an important role in the successful treatment of patients with hip-spine syndrome. Analysis of the biomechanical processes occurring in the biokinematic chain of the spine–pelvis–hip during the transition from standing position to sitting position allows us to conclude that the acetabular axis of rotation of the pelvis in space is not the only one. Classical methods for measuring PI, PT, overhang S1 are applicable for patients in a standing position and use the hip joint as a starting point, since it is the point of rotation of the pelvis in space in a standing position. Previously, using mathematical modeling, we described spatial changes in the pelvis during a given change in the body position and showed the presence of a second point of pelvis rotation in space, which appears in a sitting position. We assumed that in a sitting position, it is necessary to use other methods for calculating indicators of spinopelvic relationships for their determination.Purpose of the study was to evaluate the parameters of patients’ sagittal balance using the proposed alternative method in standing and sitting positions.Materials and methods Medical documentation and the results of X-ray examination of 20 patients with unilateral idiopathic coxarthrosis who underwent total hip replacement surgery were analyzed. The radiographic parameters were calculated: PI, PT, overhang S1 in standing and sitting positions, anterior inclination of the acetabular component; parameters PI ischial, PT ischial, deviation of the ischial tuberosities in standing and sitting positions were proposed and calculated.Results The study shows that there is no statistical difference in the values of the angles PI standard for a standing position and PI ischial for a sitting position. It corresponds to objective data and is generally accepted. Examples of changes in radiographic parameters of the sacral slope and the deviation of the ischial tuberosities were shown reflecting the rotation of the pelvis in space through the second, ischial axis, that confirm the biaxial concept of pelvic rotation.Discussion The calculations demonstrated the possibility of using alternative indicators of spinopelvic relationships (PT, distance of overhang of the sacrum (overhang S1), deviation of the ischial tuberosities). They enabled assessment of the spatial transformation of the pelvis and the ability to predict the spatial position of the acetabulum, which is an important factor for successful treatment of patients with combined pathology of the hip joint and spine.Conclusion Our findings complement the biaxial concept of pelvic rotation. An alternative method for measuring sagittal balance parameters in a sitting position has been proposed. Further research is required to assess the practical significance of this method.

Changes in spinopelvic relationships in children with spondylolisthesis after surgical treatment and their correlation with the assessment of quality of life

Objective. To assess sagittal balance parameters in children with spondylolisthesis before and after surgical treatment and to analyze their correlation with quality of life.Material and Methods. A retrospective analysis of postural radiographs of 98 children and adolescents was performed. The patients were divided into 2 groups: Group 1 included 43 patients under 17 years of age (mean age 12.0 ± 2.6 years) without spinal pathology, and Group 2 – 55 patients under 17 years of age (mean age 13.3 ± 2.5 years) with spondylolisthesis before and after surgical treatment. In patients of Group 1, the main spinopelvic parameters (PT, PI, SS, LL, PI-LL, TK) were calculated and studied. In patients of Group 2, parameters characterizing local lumbosacral kyphosis (SA, Dub-LSA, LSJA) were calculated and studied in addition to the main ones. The obtained results were compared with the conditional norm for children. The intensity of pain syndrome and quality of life were assessed using questionnaires and scales (Ped`s QL, ODI, VAS) before surgical treatment, at the time of discharge from the hospital, and after 3 months since surgery. Statistical data analysis was carried out using the statistical programming language and the R environment (version 3.6.1) in RStudio IDE (version 1.2.1335) with representation in the M ± SD format for normally distributed random variables and Me [Q1; Q3] for variables with abnormal distribution. Categorical indicators were presented as an absolute number and a percentage ratio. The null hypothesis in statistical tests was rejected at a significance level of p &lt; 0.05Results. A decrease in the intensity of pain syndrome and an improvement in the quality of life were observed after surgical treatment in all cases. Statistical analysis of the relationship between parameters characterizing local lumbosacral kyphosis (Dub-LSA, SA, LSJA) and the results of using questionnaires and scales (Ped`s QL, ODI, VAS) showed a statistically significant positive correlation (r = 0.57; p = 0.004) of the LSJA score and pain intensity assessed before surgery, as well as a statistically significant negative correlation (r = -0.47; p = 0.004) of the LSJA score before surgery and the results of the PED`s QL questionnaire after surgery. In a comparison group analysis, it was found that after surgical treatment, there was a tendency towards normalization of sagittal parameters, though their complete recovery to normal values was not achieved. Local lumbosacral kyphosis was completely eliminated in all cases.Conclusion. Correction of the angle of lumbosacral kyphosis during surgical treatment of children with spondylolisthesis directly correlates with indicators characterizing the quality of life, which makes its elimination the main purpose of the operation. The degree of correction of the sagittal balance parameters (PT, SS, LL) has no significant impact on the quality of life, and their correction to the target calculated values is not required at an initially high PI value. In cases of decompensation of the sagittal and coronal balances of the trunk with low grades of spondylolisthesis, combined with impaired gait and anterior inclination of the torso (lumbar-femoral rigidity syndrome), the instrumental restoration of segmental lordosis at the level of L5–S1 and decompression of neural structures lead to correction of sagittal balance and normalization of gait.

CORRELATION ANALYSIS OF DIFFERENT PELVIC TILT DEFINITIONS: A PRELIMINARY STUDY

Pelvic tilt (PT) is always described as the pelvic orientation along the transverse axis, yet four PT definitions were established based on different radiographic landmarks: anterior pelvic plane (PTa), the centres of femoral heads and sacral plate (PTm), pelvic outlet (PTh), and sacral slope (SS). These landmarks quantify a similar concept, yet understanding of their relationships is lacking. Some studies referred to the words “pelvic tilt” for horizontal comparisons, but their PT definitions might differ. There is a demand for understanding their correlations and differences for education and research purposes.This study recruited 105 sagittal pelvic radiographs (68 males and 37 females) from a single clinic awaiting their hip surgeries. Hip hardware and spine pathologies were examined for sub-group analysis. Two observers annotated four PTs in a gender-dependent manner and repeated it after six months. The linear regression model and intraclass correlation coefficient (ICC) were applied with a 95% significance interval.The SS showed significant gender differences and the lowest correlations to the other parameters in the male group (−0.3&lt; r &lt;0.2). The correlations of SS in scoliosis (n = 7) and hip implant (female, n = 18) groups were statistically different, yet the sample sizes were too small. PTm demonstrated very strong correlation to PTh (r &gt; 0.9) under the linear model PTm = 0.951 × PTh - 68.284.The PTm and PTh are interchangeable under a simple linear regression model, which enables study comparisons between them. In the male group, SS is more of a personalised spinal landmark independent of the pelvic anatomy. Female patients with hip implant may have more static spinopelvic relationships following a certain pattern, yet a deeper study using a larger dataset is required. The understanding of different PTs improves anatomical education.

Spinopelvic Relationship and Its Impact on Total Hip Arthroplasty

The dynamic, complex interaction among the spine, pelvis, and hip is often underappreciated, yet understanding it is vital for both arthroplasty and spinal surgeons. There is an increasing incidence of degenerative hip and spinal pathologies as a result of the ageing population. Furthermore, hip pathology can cause spine pathology and vice versa through “hip-spine” and “spine-hip syndrome.” Consequently, total hip arthroplasty (THA) and spinal fusion surgery, which both affect spinopelvic mobility, are also on the rise. Alteration in spinopelvic motion can affect the orientation of the acetabulum and, therefore, implant positioning in THA, leading to complications such as dislocation, impingement, aseptic loosening, and wear of components. This makes it imperative to assess spinopelvic motion and pelvic tilt prior to patients undergoing THA. In this paper, we explore how the surgeon should proceed to reduce risk of component malalignment, as well as the role of navigation systems in acetabular cup positioning.

Novel cross LSTM for predicting the changes of complementary pelvic angles between standing and sitting.

Sagittal spino-pelvic balance has been increasingly emphasized in hip surgery. The conversion between standing and sitting, characterized by complementary pelvic angles (pelvic tilt, pt and sacral slope, ss), involves a congruent sagittal spino-pelvic relationship. Hence, the changes of complementary pelvic angles pt, ss between standing and sitting could reflect the mechanism of sagittal spino-pelvic balance, and should be analyzed in evidence-based hip surgery planning. To this end, we propose a novel cross LSTM (C-LSTM) framework embedding the conversion between standing and sitting by cross-mapping, to predict the changes of complementary pelvic pt, ss between standing and sitting. Furthermore, to introduce the prior knowledge of the invariance of pelvic incidence, pi, two dual C-LSTMs are integrated to construct a much more powerful Fused C-LSTM. We have conducted extensive experiments on the sagittal standing-sitting dataset for the comprehensive evaluation of the proposed framework. Even in a small samples, Fused C-LSTM can achieve low prediction errors and high correlation between predicted and actual values. Notably, just based on static standing or sitting X-ray, Fused C-LSTM can obtain the change of complementary pt, ss between standing and sitting to assist in formulating a surgical hip plan that conforms to the sagittal spino-pelvic balance.

The influence of spinopelvic relationships on late dislocation of the prosthetic femoral head after total hip arthroplasty

Objective. To analyze the influence of sagittal balance parameters on the risk of dislocations of the head of the femoral component of the hip joint endoprosthesis.Material and Methods. A retrospective analysis of medical records of 113 patients with idiopathic coxarthrosis who underwent unilateral total hip arthroplasty was performed. The study assessed the parameters characterizing the sagittal balance in patients without prosthetic femoral head dislocation in the postoperative period (Group 1; n = 60) and in patients treated for prosthetic femoral head dislocation (Group 2; n = 53). Comparison of indicators was carried out by non-parametric Mann – Whitney U-test, and identification of dislocation predictors – by building single- and multi-factor logistic regression models. Differences were considered statistically significant at the achieved significance level p &lt; 0.05.Results. In Group 1, the type 3 sagittal balance according to Roussouly prevailed (48 %), in Group 2 – types 1, 2 and 4 (75 %). In patients with types 1 and 2 sagittal balance, the dislocations of the prosthetic femoral head occured 1.84 times more often than in patients with type 3, and that in patients with type 4 – 1.66 times more often.Conclusion. Patients with Roussouly type 3 sagittal balance have significantly lower risks of postoperative dislocation of the prosthetic femoral head, as compared with those with types 1, 2 and 4.

Can Abnormal Spinopelvic Relationships be Identified by Anteroposterior Pelvic Radiographs?

Abnormal spinopelvic relationships may place patients at an increased risk for instability after primary total hip arthroplasty. The purpose of this study was to determine if radiographic markers on a standing anteroposterior (AP) pelvis radiograph could identify patients with sagittal spinopelvic imbalance or spinal stiffness. Patients undergoing primary total hip arthroplasty at a single institution from 2017 to 2020 with standing AP pelvis radiographs and sitting/standing lateral radiographs were identified. AP pelvis radiographs were assessed for the following: lumbosacral hardware, spine osteophytes, disc space narrowing, scoliosis>5°, pelvic obliquity>5°, and overlap of the sacrococcygeal junction/pubic symphysis. Patients with spinopelvic imbalance and/or spinopelvic stiffness were identified. Univariate and multivariate analyses were performed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Four hundred eighty-six patients were included. Prevalence of isolated sagittal spinopelvic imbalance and isolated spinopelvic stiffness was 12% and 21%, respectively; 11% of patients had sagittal imbalance and stiffness. Overlap of the sacrococcygeal junction/pubic symphysis (OR= 10.2, 95% CI= 5.3-19.8) and presence of lumbosacral hardware (OR= 4.4, 95% CI= 2.0-9.4) were markers of an increased risk of combined sagittal imbalance and stiffness. Seventy-nine percent of patients with overlap of the sacrococcygeal junction and pubic symphysis and 82% of patients with lumbosacral hardware had an abnormal spinopelvic relationship. Isolated sagittal imbalance and stiffness were difficult to predict on standing AP pelvis radiographs. Overlap of the sacrococcygeal junction/pubic symphysis and presence of lumbosacral hardware associated with a higher risk of combined sagittal imbalance/stiffness and were present in ≥79% of patients with an abnormal spinopelvic relationship. IV; retrospective cohort study.

Implications of the spinopelvic relationship for total hip arthroplasty

Total hip arthroplasty is one of the most successful procedures in medicine. It aims to replicate the anatomy of the patient's hip joint to allow mobilization and reduce pain. To maintain stability, the changes in pelvic positioning between sitting and standing need to be considered. The spinopelvic relationship normally adjusts the position of the pelvis on sitting to antevert the acetabulum and reduce the amount of flexion at the hip. When this relationship is affected by normal variation or pathological changes, this can have implications for the arthroplasty surgeon. An anteverted or retroverted pelvis can lead to edge loading, wear, impingement and dislocation. Therefore, strategies to identify patients at risk are important to reduce complications. Sitting and standing lateral radiographs, and measurement of the change in sacral slope, can identify those with a stiff spinopelvic junction. Mitigation has mainly focused on adjusting the placement of the acetabular component within safe zones. However, use of dual mobility components, increasing offset and head size, have also been identified as possible methods. To date, there is a lack of prospective evidence or biomechanical studies assessing hip arthroplasty in these patients.

Managing Hip-Spine Concepts in the Direct Anterior Approach With Use of Fluoroscopy

BackgroundThe spinopelvic relationship in regard to total hip arthroplasty has become a topic of increasing interest in recent years. Hip arthritis and a stiff lumbar spine create a situation where the spinopelvic junction has decreased mobility, which in turn increases the risk of instability after total hip arthroplasty as the femoral acetabular joint must undergo increased motion. Regardless of the approach, surgeons should be aware of the risk of instability in patients with a stiff spinopelvic junction and the necessary modifications to component positioning to avoid postoperative instability. As many direct anterior approach surgeons use fluoroscopy for intraoperative navigation, anterior approach surgeons must also understand how to best use this technology to improve component positioning. MethodsIn this article, we address the basic concepts surrounding spinopelvic stiffness, the intraoperative component adjustments necessary for optimizing stability, and how to appropriately use fluoroscopy for navigation in the direct anterior approach. ConclusionsAppropriate use of intraoperative fluoroscopy includes understanding the impact of parallax and distortion, properly recreating the patient’s standing functional pelvic plane intraoperatively and adjusting the cup’s target position based on a preoperative understanding of the patient’s spinopelvic motion.

The Prevalence of Abnormal Spinopelvic Relationships in Patients Presenting for Primary Total Hip Arthroplasty.

BackgroundThe prevalence of an abnormal spinopelvic relationship in patients presenting for primary total hip arthroplasty (THA) is not well known. The purpose of this study was to identify the prevalence of abnormal spinopelvic relationships in patients presenting for primary THA.MethodsA retrospective chart review of 338 consecutive, nonselected patients undergoing primary THA from the practice of 2 fellowship-trained adult reconstruction surgeons was performed (J.E.O. and T.S.B.). Sitting and standing radiographs were measured for lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SSstand), and pelvic tilt; the sacral slope was also measured on sitting radiographs (SSsit). Patients were assessed for the presence of spinopelvic imbalance, defined as PI–LL>10°, and decreased spinopelvic motion, defined as SSstand–SSsit< 10°. Descriptive statistics were reported.ResultsA cohort of 338 patients was identified; 110 were excluded. In total, 228 unique patients underwent measurement. One hundred one of 228 patients (44.3%) in the cohort were female. The mean age of the cohort was 60.0 ± 13 years, with the mean body mass index of 31 ± 7 mg/kg2. Spinopelvic imbalance (PI–LL > 10°) was present in 142 of 228 patients (62.3%). Decreased motion at the spinopelvic junction (SSstand–SSsit < 10°) was present in 78 of 228 patients (34.2%). Fifty (21.9%) patients had both spinopelvic imbalance and decreased spinopelvic motion.ConclusionsIn a cohort of 228 patients presenting for primary THA, the prevalence of spinopelvic imbalance was 62.3%, the prevalence of decreased spinopelvic motion was 34.2%, and the prevalence of both spinopelvic imbalance and decreased spinopelvic motion was 22%. Hip surgeons are likely to encounter patients with abnormal spinopelvic relationships.

Use of dual mobility cups in patients undergoing primary total hip arthroplasty with prior lumbar spine fusion.

Patients undergoing primary total hip arthroplasty (THA) with prior lumbar spine fusion (LSF) are a high-risk group for instability with reported incidence of dislocation as high as 8.3% using fixed bearing femoral heads. Purpose of this study was to determine risk of post-operative instability in patients undergoing primary THA with a history of prior LSF using dual mobility acetabular cups. This was a multicenter retrospective study with 93 patients undergoing primary THA using a dual mobility cup with a prior history of instrumented LSF. There were 56 females and 47 males with an average age of 66years (46-87) and average BMI of 30 with mean follow-up of 2.7years (range 12-124months). Surgical approach included posterior (63), direct lateral (15), anterior (11), and direct superior (4). Forty-four percent had one level lumbar fusion, 29% with two levels, and 15% with three or more levels fused. The primary outcome investigated was instability. There were no cases of instability or prosthetic joint infection in this group of patients with prior lumbar spine fusion undergoing primary THA using a dual mobility cup. There was one intra-operative periprosthetic femur fracture and one case of aseptic acetabular cup loosening. Patients undergoing THA with prior LSF are at increased risk for instability due to loss of normal spinopelvic relationship. The use of dual mobility cups in patients with prior LSF undergoing primary THA appears promising with no cases of instability in this high-risk group of patients.

183. Patient outcomes following short-segment lumbar fusion are not affected by PI-LL mismatch

BACKGROUND CONTEXT Mismatch between pelvic incidence (PI) and lumbar lordosis (LL) has been emphasized as a reason for poor outcomes in deformity surgery and long-segment spinal fusions. However, literature assessing the importance of this spinopelvic relationship on patient outcomes in short segment lumbar fusions for degenerative lumbar disease is scarce. PURPOSE To determine whether patient reported outcomes are affected based on degree of postoperative PI-LL mismatch after 1- and 2-level lumbar fusion for degenerative pathology. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Three hundred and forty-eight patients who underwent a 1-2-level lumbar spine fusion procedure at a high-volume academic center were retrospectively identified. Patients were divided into two groups based on the presence of postoperative PI-LL mismatch ≤ 10° (NM) vs PI-LL mismatch >10° (M). OUTCOME MEASURES Patient reported outcome measures: SF-12 PCS and MCS, ODI, VAS Back, VAS Leg. Spinopelvic measurements: pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), lumbar lordosis (LL). METHODS Preoperative and postoperative radiographic measurements were obtained for all patients. Those with less than one-year follow-up were excluded. Univariate analysis with an independent t-test or Mann-Whitney U test was used to compare differences between groups. Multiple linear regression was used to determine if postoperative PI-LL mismatch was an independent predictor of change in each patient outcome. RESULTS Sixty-seven patients were included in the NM group compared to 281 patients in the M group. There were no baseline differences (p > 0.05) in age, sex, BMI, CCI, smoking status, follow-up, preoperative diagnosis, number of levels decompressed and fused, or number of cases with TLIF or ALIF. On univariate analysis, there was a significant difference pre- and postoperatively in PT, PI, LL and PI-LL between the two groups at baseline and postoperatively (p 0.05). In addition, having a postoperative PI-LL mismatch was not found to be an independent predictor of any health-related outcome score on multiple linear regression analysis. CONCLUSIONS Pelvic incidence minus lumbar lordosis is recognized as an important spinopelvic parameter to normalize in deformity surgery; however, this importance is less clear in short-segment lumbar fusion for degenerative pathology. The results of this study show that even though the M group had a higher degree of mismatch pre- and postoperatively, there was no difference in patient-reported outcomes before or after surgery. This is one of the first studies to report on short-term patient outcomes based on spinopelvic parameters in routine lumbar degenerative cases. Further research is needed to elucidate this important relationship. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Prevalence of Anterior Femoral Neck Osteophyte in a Total Hip Arthroplasty Population: Analysis of Preoperative Surgical Plans.

Despite strongly positive results of total hip arthroplasty (THA), patients remain at risk for complications including dislocation. Spinopelvic motion and the hip-spine relationship have been recognized as important factors in surgical planning and implant positioning in THA. Periarticular osteophytes are one of the hallmark pathoanatomic features of osteoarthritis and may influence implant positioning and joint stability; residual osteophytes at the anterior femoral neck may cause anterior impingement and posterior instability. No studies have been identified which establish the prevalence of anterior femoral neck osteophyte for incorporation into THA planning. 413 consecutive patients scheduled for THA underwent preoperative planning taking into account spinopelvic motion to establish optimal component position. Each surgical plan was reviewed retrospectively by four independent raters who were blinded to other imaging and intraoperative findings. Anterior femoral neck osteophytes were rated as being absent, minor, or extensive for each case. A single outlying rater was excluded. Inter-rater reliability was calculated manually. The patient group comprised 197 male and 216 female hips, with a mean age of 63 years (range 32–91). The presence of anterior femoral neck osteophytes was identified in a mean of 82% of cases (range 78–86%). A significant number of patients were found to have large or extensive osteophytes present in this location (mean 27%; range 23–31%). Inter-rater reliability was 70%. A large majority of our THA patients were found to have anterior femoral neck osteophytes. These must be considered during preoperative planning with respect to the spinopelvic relationship. Failure to identify and address osteophytes intraoperatively may increase the risk of impingement in flexion and/or internal rotation, leading to decreased range of motion, joint instability, and possibly dislocation. Planned future directions include incorporation of an impingement and instability model into preoperative planning for THA.

BIOMECHANICAL MODELING IN SURGICAL TREATMENT OF A PATIENT WITH TRUE LUMBAR SPONDYLOLISTHESIS

Objective. To assess the results of clinical approbation of individual finite-element biomechanical model of a patient’s spino-pelvic complex with subsequent modeling of the best option of surgical treatment. Material and Methods. A biomechanical modeling of changes in the sagittal profile of a patient with degenerative disease of the lumbosacral spine, bilateral spondylolysis, and unstable grade 2 spondylolisthesis of the L4 vertebra was performed. The developed biomechanical model made it possible to assess the characteristics of the stress-strain state of the spinal motion segments aroused due to development of the disease. Within the built biomechanical model of the patient’s spino-pelvic complex, a corrective operation was further modeled that assumed a preservation of harmonious profile of sagittal spino-pelvic relationships. Post-correction characteristics of the stress-strain state of spinal motion segments were studied and compared with preoperative parameters of the biomechanical model. Results. Using methods of biomechanics and computer modeling allowed to calculate the stress-strain state of the lumbosacral spine under static load for two options of fixation and intervertebral cage implantation at the L4–L5 level: four transpedicular screws (L4–L5 vertebrae) and six transpedicular screws (L3–L4–L5 vertebrae). The simulation results showed that neither metal implants, nor elements of the lumbosacral spine experienced critical stresses and deformations that could lead to the destruction and instability of the implant. Conclusion. The developed individual biomechanical finite-element solid model of the spine and pelvis allowed for biomechanical justification of prerequisites for the formation and further progression of degenerative changes in spinal motion segments associated with violations of the sagittal profile due to grade 2 spondylolisthesis of the L4 vertebra. The model built on the results of radiological examination biomechanically substantiated the best option of corrective spine surgery allowing to minimize stresses and deformations by choosing reasonable magnitude of correction of sagittal spino-pelvic parameters and configuration of transpedicular system.

The spinopelvic relationship made simple: What every hip surgeon needs to know to prevent instability in high-risk patients undergoing total hip arthroplasty

Increasingly the relationship between the hip and spine has become recognized as a risk factor for postoperative instability following total hip arthroplasty. Thorough understanding of the relationship between the spine and pelvis, spinopelvic parameters, and normal and pathologic spinopelvic motion is critical to surgical planning and prevention of instability after total hip arthroplasty. This review details spinopelvic motion and postural changes that predispose patients to instability, guides readers through a preoperative risk assessment tool and our stepwise protocol to classify spinopelvic motion and prevent instability.

Analyse radiographique 3D en position debout : relation entre paramètres radiologiques sagittaux et incapacité fonctionnelle dans la pathologie rachidienne

PurposeTo clarify the relationship between whole body sagittal radiographic parameters and health related quality of life (HRQOL) in patients with spinal disease, and further analyse such relationship based on the pelvic incidence (PI) value. Methods100 patients (mean age: 64.4 years, M/F=50/50) with lumbar degenerative disease or spinal deformity were prospectively investigated. Following Oswestry Disability Index (ODI) and Scoliosis Research Society Score 22 (SRS-22) questionnaire, whole body sagittal X-ray parameters were measured using a slot-scanning 3D X-ray imager (EOS). Correlations between such radiographic parameters and ODI/SRS-22 scores were analysed. Then, patients were divided into three groups based on the PI value (PI≤45°, 45°<PI≤60°, and 60°<PI), and correlations between the significantly correlated parameters and ODI/SRS-22 scores were analysed for each PI group. ResultsC2-7 lordosis, pelvic tilt (PT), pelvic incidence (PI), PI minus lumbar lordosis (PI-LL), sagittal vertical axis (SVA), full balance integrated index (FBI), and knee flexion angle (KneeFlex) had a significant correlation with ODI or SRS-22 scores. Among those parameters, PI and FBI showed a significant correlation with both ODI and SRS-22 scores. High PI (>60°) group showed a strong correlation (R>0.4) with both ODI and SRS-22 scores for PI-LL parameter. ConclusionsPI and FBI showed a significant correlation with both ODI and SRS-22 scores. PI-LL mismatch was strongly correlated with disability in high PI patients. Our study results may indicate that it is important to pay attention to the PI value in addition to the spinopelvic relationship. Level of evidenceII, prospective study.

Влияние локального лордозирующего трансфораминального межтелового спондилодеза на смежные сегменты и позвоночно-тазовые отношения. Рентгенологическое исследование

Влияние локального лордозирующего трансфораминального межтелового спондилодеза на смежные сегменты и позвоночно-тазовые отношения. Рентгенологическое исследование

Relationship Between Lumbar Lordosis and Pelvic Incidence in the Adolescent Patient: Normal Cohort Analysis and Literature Comparison*

Study DesignRetrospective review; literature comparison. ObjectivesTo review the literature on the relationship between lumbar lordosis (LL) and pelvic incidence (PI) and evaluate this relationship in asymptomatic adolescents while testing the validity of previously reported adult correlation models between LL and PI in an adolescent population. Summary of Background DataAccurate understanding of the normal spinopelvic relationship is critical when considering surgical fusion of the lumbar spine. Many studies have reported relationships between pelvic measurements and LL in adult populations, but data in pediatric populations is lacking. MethodsA literature search was performed to identify previously reported relationships between pelvic parameters and LL in adults and pediatric patients. A cohort of 125 asymptomatic adolescent patients evaluated at our institution was evenly split into two cohorts for model development and validation. Linear regression between LL and PI was performed. The resultant regression model was tested in the validation cohort along with previously reported formulae with LL as a function of PI. Mean absolute error (MAE) was calculated and compared between prior models and the newly developed adolescent model using analysis of variance and post-hoc testing. ResultsIn our adolescent cohort (mean age: 13 ± 2), there was a strong correlation between PI and LL (r = 0.53). Regression analysis in the development cohort produced the following predictive model: LL = 0.66(PI) + 24.2. Testing in the validation cohort revealed a good correlation between predicted and actual LL (r = 0.51) and an MAE of 8.3. All but three previously reported models functioned with similar accuracy in the adolescent population, with only two methods having an MAE over 10. ConclusionsThe majority of previously published formulae for predicting LL as a function of PI developed in adults can be extrapolated to adolescent populations. These relationships are important in understanding how to surgically restore the sagittal alignment in adolescents with spinal deformity. Level of EvidenceLevel IV.