Etiology, Evaluation, and Treatment of Failed Back Surgery Syndrome

The study aimed to review the etiology of failed back surgery syndrome (FBSS) and to propose a treatment algorithm based on a systematic review of the current literature and individual experience. FBSS is a term that groups the conditions with recurring low back pain after spine surgery with or without a radicular component. Since the information on FBSS incidence is limited, data needs to be retrieved from old studies. It is generally accepted that its incidence ranges between 10% and 40% after lumbar laminectomy with or without fusion. Although the etiology of FBSS is not completely understood, it is possibly multifactorial, and the causative factors may be categorized into preoperative, operative, and postoperative factors. The evaluation of patients with FBSS symptoms should ideally initiate with reviewing the patients’ clinical history (observing “red flags”), followed by a detailed clinical examination and imaging (whole-body X-ray, magnetic resonance imaging, and computed tomography). FBSS is a complex and difficult pathology, and its accurate diagnosis is of utmost importance. Its management should be multidisciplinary, and special attention should be provided to cases of recurrent disc herniation and postoperative spinal imbalance

Vertebral Augmentation: State of the Art

Osteoporotic vertebral compression fractures (OVF) are an increasing public health problem. Cement augmentation (vertebroplasty of kyphoplasty) helps stabilize painful OVF refractory to medical treatment. This stabilization is thought to improve pain and functional outcome. Vertebroplasty consists of injecting cement into a fractured vertebra using a percutaneous transpedicular approach. Balloon kyphoplasty uses an inflatable balloon prior to injecting the cement. Although kyphoplasty is associated with significant improvement of local kyphosis and less cement leakage, this does not result in long-term clinical and functional improvement. Moreover, vertebroplasty is favored by some due to the high cost of kyphoplasty. The injection of cement increases the stiffness of the fracture vertebrae. This can lead, in theory, to adjacent OVF. However, many studies found no increase of subsequent fracture when comparing medical treatment to cement augmentation. Kyphoplasty can have a protective effect due to restoration of sagittal balance

Roussouly's sagittal spino-pelvic morphotypes as determinants of gait in asymptomatic adult subjects.

Sagittal alignment is known to greatly vary between asymptomatic adult subjects; however, there are no studies on the possible effect of these differences on gait. The aim of this study is to investigate whether asymptomatic adults with different Roussouly sagittal alignment morphotypes walk differently. Ninety-one asymptomatic young adults (46M & 45W), aged 21.6±2.2years underwent 3D gait analysis and full body biplanar X-rays with three-dimensional (3D) reconstructions of their spines and pelvises and generation of sagittal alignment parameters. Subjects were divided according to Roussouly's sagittal alignment classification. Sagittal alignment and kinematic parameters were compared between Roussouly types. 17 subjects were classified as type 2, 47 as type 3, 26 as type 4 but only 1 as type 1. Type 2 subjects had significantly more mean pelvic retroversion (less mean pelvic tilt) during gait compared to type 3 and 4 subjects (type 2: 8.2°; type 3:11.2°, type 4: 11.3°) and significantly larger ROM pelvic obliquity compared to type 4 subjects (type 2: 11.0°; type 4: 9.1°). Type 2 subjects also had significantly larger maximal hip extension during stance compared to subjects of types 3 and 4 (type 2: -11.9°; type 3: -8.8°; type 4: -7.9°) and a larger ROM of ankle plantar/dorsiflexion compared to type 4 subjects (type 2: 31.1°; type 4: 27.9°). Subjects with type 2 sagittal alignment were shown to have a gait pattern involving both increased hip extension and pelvic retroversion which could predispose to posterior femoroacetabular impingement and consequently osteoarthritis.This study was supported by the research council of the University of Saint-Joseph (grant number: FM189). The study sponsors were involved in neither the study design, collection, analysis and interpretation of data nor in the writing of the manuscript; nor in the decision to submit the manuscript for publication

How the type of sagittal alignment defined by Roussouly determines the gait of asymptomatic adult subject

While curvatures of the sagittal spine are known to greatly differ among asymptomatic adult subjects, there are no studies that determine whether this heterogeneous normality affects gait. This study aimed to elucidate the relationships between normal sagittal spine profiles and gait in asymptomatic adult subjects. Ninety-one asymptomatic adult subjects (age = 21.6 ±2.2, 47 M & 44F) with no prior orthopedic treatment underwent full body biplanar X rays with 3D reconstruction of the spine and pelvis. The following sagittal spino-pelvic parameters were generated from the 3D reconstructions: pelvic incidence, sacral slope, pelvic tilt, L1L5 lordosis, L1-S1 lordosis, T1-T12 kyphosis and T4-T2 kyphosis. Lower limb kinematics was assessed using 3D gait analysis. Each subject was classified into one of the 4 types of normal sagittal alignment previously described by Roussouly. Kruskal-Wallis test was used to evaluate the differences in gait and spino-pelvic parameters between the Roussouly types

How do postural parameters vary during walking in asymptomatic adults? A registration technique of subject-specific 3D skeletal reconstruction during gait

Postural skeletal alignment is altered with age due to intervertebral disc and joint degeneration, consequently affecting quality of life (QoL) and activities of daily living, such as gait. Postural alignment parameters of the spine, pelvis, hips and lower limbs, measured on static standing radiographs, have been widely studied in asymptomatic subjects and subjects affected by various pathologies. However, while most of these parameters are positional and could vary during gait, there are currently no studies investigating how they are modified during walking

Influence of Spino-Pelvic and Postural Alignment Parameters on Gait Kinematics

Introduction: Postural alignment is altered with spine deformities that might occur with age. Alteration of spino-pelvic and postural alignment parameters are known to affect daily life activities such as gait. It is still unknown how spino-pelvic and postural alignment parameters are related to gait kinematics. Research question: To assess the relationships between spino-pelvic/postural alignment parameters and gait kinematics in asymptomatic adults. Methods: 134 asymptomatic subjects (aged 18-59 years) underwent 3D gait analysis, from which kinematics of the pelvis and lower limbs were extracted in the 3 planes. Subjects then underwent full-body biplanar X-rays, from which skeletal 3D reconstructions and spino-pelvic and postural alignment parameters were obtained such as sagittal vertical axis (SVA), center of auditory meatus to hip axis plumbline (CAM-HA), thoracic kyphosis (TK) and radiologic pelvic tilt (rPT). In order to assess the influence of spino-pelvic and postural alignment parameters on gait kinematics a univariate followed by a multivariate analysis were performed. Results: SVA was related to knee flexion during loading response (β = 0.268); CAM-HA to ROM pelvic obliquity (β = -0.19); rPT to mean pelvic tilt (β = -0.185) and ROM pelvic obliquity (β = -0.297); TK to ROM hip flexion/extension in stance (β = -0.17), mean foot progression in stance (β = -0.329), walking speed (β = -0.19), foot off (β = 0.223) and step length (β = -0.181). Significance: This study showed that increasing SVA, CAM-HA, TK and rPT, which is known to occur in adults with spinal deformities, could alter gait kinematics. Increases in these parameters, even in asymptomatic subjects, were related to a retroverted pelvis during gait, a reduced pelvic obliquity and hip flexion/extension mobility, an increased knee flexion during loading response as well as an increase in external foot progression angle. This was associated with a decrease in the walking pace: reduced speed, step length and longer stance phase

Toward understanding the underlying mechanisms of pelvic tilt reserve in adult spinal deformity: the role of the 3D hip orientation

Purpose: To explore 3D hip orientation in standing position in subjects with adult spinal deformity (ASD) presenting with different levels of compensatory mechanisms. Methods: Subjects with ASD (n = 159) and controls (n = 68) underwent full-body biplanar X-rays with the calculation of 3D spinopelvic, postural and hip parameters. ASD subjects were grouped as ASD with knee flexion (ASD-KF) if they compensated by flexing their knees (knee flexion ≥ 5°), and ASD with knee extension (ASD-KE) otherwise (knee flexion < 5°). Spinopelvic, postural and hip parameters were compared between the three groups. Univariate and multivariate analyses were then computed between spinopelvic and hip parameters. Results: ASD-KF had higher SVA (67 ± 66 mm vs. 2 ± 33 mm and 11 ± 21 mm), PT (27 ± 14° vs. 18 ± 9° and 11 ± 7°) and PI-LL mismatch (20 ± 26° vs − 1 ± 18° and − 13 ± 10°) when compared to ASD-KE and controls (all p < 0.05). ASD-KF also had a more tilted (34 ± 11° vs. 28 ± 9° and 26 ± 7°), anteverted (24 ± 6° vs. 20 ± 5° and 18 ± 4°) and abducted (59 ± 6° vs. 57 ± 4° and 56 ± 4°) acetabulum, with a higher posterior coverage (100 ± 6° vs. 97 ± 7° for ASD-KE) when compared to ASD-KE and controls (all p < 0.05). The main determinants of acetabular tilt, acetabular abduction and anterior acetabular coverage were PT, SVA and LL (adjusted R² [0.12; 0.5]). Conclusions: ASD subjects compensating with knee flexion have altered hip orientation, characterized by increased posterior coverage (acetabular anteversion, tilt and posterior coverage) and decreased anterior coverage which can together lead to posterior femoro-acetabular impingement, thus limiting pelvic retroversion. This underlying mechanism could be potentially involved in the hip-spine syndrome

Gait kinematic alterations in subjects with adult spinal deformity and their radiological determinants

Background: Adults with spinal deformity (ASD) are known to have postural malalignment affecting their quality of life. Classical evaluation and follow-up are usually based on full-body static radiographs and health related quality of life questionnaires. Despite being an essential daily life activity, formal gait assessment lacks in clinical practice. Research Question: What are the main alterations in gait kinematics of ASD and their radiological determinants? Methods: 52 ASD and 63 control subjects underwent full-body 3D gait analysis with calculation of joint kinematics and full-body biplanar X-rays with calculation of 3D postural parameters. Kinematics and postural parameters were compared between groups. Determinants of gait alterations among postural radiographic parameters were explored. Results: ASD had increased sagittal vertical axis (SVA:34 ± 59 vs −5 ± 20 mm), pelvic tilt (PT:19 ± 13 vs 11 ± 6°) and frontal Cobb (25 ± 21 vs 4 ± 6°) compared to controls (all p < 0.001). ASD displayed decrease walking speed (0.9 ± 0.3 vs 1.2 ± 0.2 m/s), step length (0.58 ± 0.11 vs 0.64 ± 0.07 m) and increased single support (0.45 ± 0.05 vs 0.42 ± 0.04 s). ASD walked with decreased hip extension in stance (−3 ± 10 vs −7 ± 8°), increased knee flexion at initial contact and in stance (10 ± 11 vs 5 ± 10° and 19 ± 7 vs 16 ± 8° respectively), and decreased knee flexion/extension ROM (55 ± 9 vs 59 ± 7°). ASD had increased trunk flexion (12 ± 12 vs 6 ± 11°) and reduced dynamic lumbar lordosis (−11 ± 12 vs −15 ± 7°, all p < 0.001). Sagittal knee ROM, walking speed and step length were negatively determined by SVA; lack of lumbar lordosis during gait was negatively determined by radiological lumbar lordosis. Significance: Static compensations in ASD persist during gait, where they exhibit a flexed attitude at the trunk, hips and knees, reduced hip and knee mobility and loss of dynamic lordosis. ASD walked at a slower pace with increased single and double support times that might contribute to their gait stability. These dynamic discrepancies were strongly related to static sagittal malalignment

Five-year outcomes of the First Distal Uninstrumented Vertebra after posterior fusion for Adolescent Idiopathic Scoliosis Lenke 1 or 2

BACKGROUND: Tilt of the First Distal Uninstrumented Vertebra (FDUV) reflects changes in the main curve and compensatory lumbar curve after posterior fusion to treat thoracic Adolescent Idiopathic Scoliosis (AIS). HYPOTHESIS: FDUV tilt 5 years or more post-fusion depends chiefly on reduction of the main curve and on other factors such as selection of the last instrumented vertebra. MATERIAL AND METHOD: A multicenter retrospective cohort of 182 patients with Lenke 1 or 2 AIS treated with posterior instrumentation and followed up for a mean of 8 years and a minimum of 5 years was studied. The patients were divided into two groups based on whether tilt of the upper endplate of the FDUV was ≤5° or >5°at last follow-up. Variables associated with tilt were identified by multiple logistic regression. RESULTS: Six variables were significantly associated with FDUVtilt: percentage of correction at last follow-up, correction loss, lumbar modifier B, number of instrumented vertebrae, inclusion within the instrumentation of the distal neutral vertebra, and inclusion within the instrumentation of the lowest vertebra intersected by the central sacral vertical line. DISCUSSION AND CONCLUSION: The main variables associated with FDUVtilt ≤5° were a final correction percentage ≥60% and absence of correction loss between the postoperative period and last follow-up. Given the stable reduction provided by contemporary instrumentations, we recommend selective thoracic fusion of Lenke 1 or 2 AIS with lumbar modifiers A, B, and C. The lowest instrumented vertebra should be either the neutral vertebra or the vertebra intersected by the central sacral vertical line if it is distal to the neutral vertebra. LEVEL OF EVIDENCE IV: Retrospective multicenter study

How the type of sagittal alignment dfined by Roussouly determines the gait of asymptomatic adult subject

International audienceWhile curvatures of the sagittal spine are known to greatly differ among asymptomatic adult subjects, there are no studies that determine whether this heterogeneous normality affects gait. This study aimed to elucidate the relationships between normal sagittal spine profiles and gait in symptomatic adult subjects. Ninety-one asymptomatic adult subjects (age = 21.6 ±2.2, 47 M & 44F) with no prior orthopedic treatment underwent full body biplanar X rays with 3D reconstruction of the spine and pelvis. The following sagittal spino-pelvic parameters were generated from the 3D reconstructions: pelvic incidence, sacral slope, pelvic tilt, L1L5 lordosis, L1-S1 lordosis, T1-T12 kyphosis and T4-T2 kyphosis. Lower limb kinematics was assessed using 3D gait analysis. Each subject was classified into one of the 4 types of normal sagittal alignment previously described by Roussouly. Kruskal-Wallis test was used to evaluate the differences in gait and spino-pelvic parameters between the Roussouly types.While curvatures of the sagittal spine are known to greatly differ among asymptomatic adult subjects, there are no studies that determine whether this heterogeneous normality affects gait. This study aimed to elucidate the relationships between normal sagittal spine profiles and gait in asymptomatic adult subjects. Ninety-one asymptomatic adult subjects (age = 21.6 ±2.2, 47 M & 44F) with no prior orthopedic treatment underwent full body biplanar X rays with 3D reconstruction of the spine and pelvis. The following sagittal spino-pelvic parameters were generated from the 3D reconstructions: pelvic incidence, sacral slope, pelvic tilt, L1L5 lordosis, L1-S1 lordosis, T1-T12 kyphosis and T4-T2 kyphosis. Lower limb kinematics was assessed using 3D gait analysis. Each subject was classified into one of the 4 types of normal sagittal alignment previously described by Roussouly. Kruskal-Wallis test was used to evaluate the differences in gait and spino-pelvic parameters between the Roussouly types