Alexis Shelokov

A multicenter retrospective study of the clinical results of the LINK SB Charité intervertebral prosthesis. The initial European experience.

Methods. independent analysis by chart review included patient demographics, surgical data, end a comparison of presurgical to follow-up data. Data were analysed from 93 patients (average age - 43.0 ± 7.3) in Whom e total of 139 Model III prostheses (Waldemar Link GmbH & Co, Hamburg, Germany) Were implanted. Results. The predominant diagnostic Indication for the disc was degenerative disc disease (52.4%). The L4-L5 and L5-S1 levels comprised 87.1% of all levels implanted. The average follow-up was 11.5 ± 7.4 months, After disc implantation, a significant proportion of the patient sample experienced pain relief (P < 0.05). Improvements were also noted in pain intensity, walking distance, lumbar mobility, and the percentage of patients showing a positive SLR or neurological weakness, No difference in word status after disc implantation could be detected. Device failure, migration, or dislocation occurred in 6 of 93 (6.5%) patients. Conclusions. This study represents the largest multi-center case series of any functional artificial disc implantation. Carefully controlled, prospective studies that compare disc implantation and fusion are warranted.

Pain and disability determine treatment modality for older patients with adult scoliosis, while deformity guides treatment for younger patients.

Study Design. Multi-center, retrospective review. Objective. Identify age associated clinical and radiographic features correlating with AS treatment. Summary of Background Data. Little information exists about factors determining treatment for adult scoliosis (AS). Existing studies have not evaluated age stratified differences. Methods. Multicenter, retrospective review of 290 patients treated for AS. Patients divided into operative (OP) or nonoperative (NON), and age stratified into 3 groups (G1 = <50 years, G2 = 50–65 years, G3 = >65 years). Demographic and spinopelvic radiographic parameters evaluated. Health-related quality of life (HRQL) measures included SRS-22, Oswestry Disability Index (ODI), visual analog pain scale. Results. Treatment groups (OP, n = 137; NON, n = 153) demonstrated similar age (OP = 52.7 years; NON = 55.5 years; P > 0.05) and cormorbidities. OP had larger thoracic curves than NON (OP = 51°, NON = 45°; P < 0.05). OP had worse HRQL scores than NON (SRS = 2.95 vs. 3.12, P < 0.05; ODI = 33.4 vs. 28.7, P < 0.05; visual analog pain scale = 6.9 vs. 5.6, P < 0.05, respectively). Age stratification of OP demonstrated larger curves in G1 and G2 versus G3, progressively worsening sagittal imbalance in older age groups, and worse HRQL scores in G3 versus G1 and G2. Age stratification of NON demonstrated worsening sagittal imbalance with age, however, other radiographic values and HRQL scores were similar between all NON age groups. Treatment stratification of age groups demonstrated G1-OP had greater deformity than G1-NON (mean thoracic curve: G1-OP = 53°, G1-NON = 43°; P < 0.05) but similar HRQL values. Whereas G2 and G3-OP had similar radiographic coronal and sagittal values as G2 and G3-NON, but worse HRQL scores. Conclusion. Counter to previous reports, age, cormorbidities, and sagittal balance did not influence treatment modality for AS. Operative treatment for younger patients was driven by increased coronal plane deformity. Conversely, pain and disability mandated treatment for olderpatients, independent of radiographic measures. These findings suggest that AS patients do not become uniformly disabled with age, and that disability can not be solely predicted by radiographic findings. These data should be considered when considering treatment for AS.

Does vertebral level of pedicle subtraction osteotomy correlate with degree of spinopelvic parameter correction?: Clinical article

OBJECT Pedicle subtraction osteotomy (PSO) is a spinal realignment technique that may be used to correct sagittal spinal imbalance. Theoretically, the level and degree of resection via a PSO should impact the degree of sagittal plane correction in the setting of deformity. However, the quantitative effect of PSO level and focal angular change on postoperative spinopelvic parameters has not been well described. The purpose of this study is to analyze the relationship between the level/degree of PSO and changes in global sagittal balance and spinopelvic parameters. METHODS In this multicenter retrospective study, 70 patients (54 women and 16 men) underwent lumbar PSO surgery for spinal imbalance. Preoperative and postoperative free-standing sagittal radiographs were obtained and analyzed by regional curves (lumbar, thoracic, and thoracolumbar), pelvic parameters (pelvic incidence and pelvic tilt [PT]) and global balance (sagittal vertical axis [SVA] and T-1 spinopelvic inclination). Correlations between PSO parameters (level and degree of change in angle between the 2 adjacent vertebrae) and spinopelvic measurements were analyzed. RESULTS Pedicle subtraction osteotomy distribution by level and degree of correction was as follows: L-1 (6 patients, 24°), L-2 (15 patients, 24°), L-3 (29 patients, 25°), and L-4 (20 patients, 22°). There was no significant difference in the focal correction achieved by PSO by level. All patients demonstrated changes in preoperative to postoperative parameters including increased lumbar lordosis (from 20° to 49°, p < 0.001), increased thoracic kyphosis (from 30° to 38°, p < 0.001), decreased SVA and T-1 spinopelvic inclination (from 122 to 34 mm, p < 0.001 and from +3° to -4°, p < 0.001, respectively), and decreased PT (from 31° to 23°, p < 0.001). More caudal PSO was correlated with greater PT reduction (r = -0.410, p < 0.05). No correlation was found between SVA correction and PSO location. The PSO degree was correlated with change in thoracic kyphosis (r = -0.474, p < 0.001), lumbar lordosis (r = 0.667, p < 0.001), sacral slope (r = 0.426, p < 0.001), and PT (r = -0.358, p < 0.005). CONCLUSIONS The degree of PSO resection correlates more with spinopelvic parameters (lumbar lordosis, thoracic kyphosis, PT, and sacral slope) than PSO level. More importantly, PSO level impacts postoperative PT correction but not SVA.

Complications of Cervical discography : Findings in a large series

The use of cervical discography remains controversial. Recently in a small patient group, a high complication rate was reported. The purpose of this study was to determine the incidence of complications associated with cervical discography. Data from 161 cervical discography procedures, involving 269 disc injections, were recorded. There were four complications; thus the complication rate was 2.48% based on the number of procedures and 1.49% based on the number of disc injections. The complications were two cases of discitis, one postinjection hematoma, and one patient developed significant headache pain after the disc injection. Reports of high complication rates associated with cervical discography and serious outcomes from them should serve as a warning that the procedure does have associated risks, and great care is warranted. However, based on the results of our study, discography is not an inherently unsafe procedure. It can be accomplished with few complications when performed in sterile conditions by those well experienced with cervical disc injections.

Biomechanical comparison of anterior instrumentation for the cervical spine.

Metal fixation has been advocated to achieve immediate local stabilization during anterior cervical fusion surgery. Screw loosening, screw backout, and breakage of screws or plates remain clinical complications that warrant concern. This study examined the biomechanical characteristics of a prototype anterior cervical plating system with unique screw and plate geometries in comparison to a fixation system currently used clinically. Compared with a standard screw design, a taper screw design resulted in increased ultimate strength and fatigue life. The addition of a locking pin hole in the tapered screw made the screws fatigue life comparable to the standard design. Pullout strength was comparable in all screw designs. The prototype fixation system had higher strength in pure compression and compression with bending than the comparative system, while also demonstrating improved fatigue characteristics. The tensile bending stiffness of the prototype was double that of the comparative system and within the anatomical range of cervical vertebrae, the bending moment was greater. Torsional yield strength was greater than the reported breaking strength of cervical disc in situ for both systems. The unique designs of the screw and plate geometry resulted in an anterior cervical plate fixation system that is stronger with decreased risk of fatigue failure than a currently used system. Clinical evaluation in patients requiring immediate stabilization is warranted.

Does Recombinant Human Bone Morphogenetic Protein-2 Use in Adult Spinal Deformity Increase Complications and Are Complications Associated With Location of rhbmp-2 Use? A Prospective, Multicenter Study of 279 Consecutive Patients

Study Design. Multicenter, prospective analysis of consecutive patients with adult spinal deformity (ASD). Objective. Evaluate complications associated with recombinant human bone morphogenetic protein-2 (rhBMP-2) use in ASD. Summary of Background Data. Off-label rhBMP-2 use is common; however, underreporting of rhBMP-2 associated complications has been recently scrutinized. Methods. Patients with ASD consecutively enrolled into a prospective, multicenter database were evaluated for type and timing of acute perioperative complications. Inclusion criteria: age 18 years and older, ASD, spinal arthrodesis of more than 4 levels, and 3 or more months of follow-up. Patients were divided into those receiving rhBMP-2 (BMP) or no rhBMP-2 (NOBMP). BMP divided into location of use: posterior (PBMP), interbody (IBMP), and interbody + posterior spine (I + PBMP). Correlations between acute perioperative complications and rhBMP-2 use including total dose, dose/level, and location of use were evaluated. Results. A total of 279 patients (mean age: 57 yr; mean spinal levels fused: 12.0; and mean follow-up: 28.8 mo) met inclusion criteria. BMP (n = 172; average posterior dose = 2.5 mg/level, average interbody dose = 5 mg/level) had similar age, smoking history, previous spine surgery, total spinal levels fused, estimated blood loss, and duration of hospital stay as NOBMP (n = 107; P > 0.05). BMP had greater Charlson Comorbidity Index (1.9 vs. 1.2), greater scoliosis (43° vs. 38°), longer operative time (488.2 vs. 414.6 min), more osteotomies per patient (4.0 vs. 1.6), and greater percentage of anteroposterior fusion (APSF; 20.9% vs. 8.4%) than NOBMP, respectively (P < 0.05). BMP had more total complications per patient (1.4 vs. 0.6) and more minor complications per patient (0.9 vs. 0.2) than NOBMP, respectively (P < 0.05). NOBMP had more complications requiring surgery per patient than BMP (0.3 vs. 0.2; P < 0.05). Major, neurological, wound, and infectious complications were similar for NOBMP, BMP, PBMP, IBMP, and I + PBMP (P > 0.05). Multivariate analysis demonstrated small to nonexistent correlations between rhBMP-2 use and complications. Conclusion. RhBMP-2 use and location of rhBMP-2 use in ASD surgery, at reported doses, do not increase acute major, neurological, or wound complications. Research is needed for higher rhBMP-2 dosing and long-term follow-up. Level of Evidence: 2

Spine care: evaluation of the efficacy and cost of emerging technology.

Over the last decade a number of new technologies have been introduced to the area of spine care. Although this recent explosion of innovation has brought advances to patient care, it has also brought concerns regarding overuse, increasing costs, and safety. A value-based approach to assessing and purchasing new technology depends on a shift toward comparative effectiveness analysis, transparency in pricing and potential conflicts of interest, and an alignment of incentives and goals among purchasers, consumers, and payers. How to assess the effectiveness of new technology in patient care is an unresolved issue for any cost-effectiveness analysis, as models traditionally used to assess medical therapies (ie, quality-adjusted life years) may not be directly applicable to analysis of surgical intervention. Spine surgeons must be involved in multidisciplinary collaborative efforts to develop models of efficacy analysis and to direct outcomes-based research to appropriately evaluate the benefits of surgical interventions and new technologies.

Residual gait abnormalities in surgically treated spondylolisthesis.

The authors retrospectively studied seven patients who had in situ fusion as adolescents for high-grade (IV, V) spondylolisthesis unresponsive to more conservative means. All patients achieved solid bony union; their pain was relieved; and hamstring spasm had resolved. The authors sought to determine whether crouch gait or any other abnormalities could be demonstrated in patients exhibiting clinical parameters of success. Each patient underwent gait analysis, radiographic analysis, and a physical examination. Four of seven patients demonstrated slight degrees of forward trunk lean during varying phases of gait accompanied by increased hip flexion. One patient demonstrated increased trunk extension accompanied by limited hip flexion. Two patients were essentially normal. The authors were unable to quantify residual crouch in these patients with solidly fused high-grade spondylolisthesis.