Do TLIF and PLIF Techniques Differ in Perioperative Complications? - Comparison of Complications Rates of Two High Volume Centers.

STUDY DESIGN: Retrospective bicentric Cohort Study. OBJECTIVE: Posterior (PLIF) and transforaminal lumbar interbody fusion (TLIF) have been clinically proven for the surgical treatment of degenerative spinal disorders. Despite many retrospective studies, the superiority of either technique has not been proven to date. In the literature, the complication rate of the conventional PLIF technique is reported to be significantly higher, but with inconsistent complication recording. In this retrospective bicentric study, a less invasive PLIF technique was compared with the conventional TLIF technique and complications were recorded using the validated SAVES V2 classification system. METHODS: 1142 patients underwent PLIF (702) or TLIF (n = 440) up to 3 levels in two specialized centers. Epidemiological data, intra- and postoperative complications during hospitalization and after discharge were analyzed according to SAVES V2. RESULTS: The overall complication rate was 13.74%. TLIF-patients had slightly significant more complications than PLIF-patients (TLIF = 16.6%/PLIF = 11.9%, P = .0338). Accordingly, complications during revision surgeries were more frequent in the first cohort (TLIF = 20.9%/PLIF = 12.6%; P = .03252). In primary interventions, the surgical technique did not correlate with the complication rate (TLIF = 12.4%/PLIF = 11.7%). There were no significant differences regarding severity of complications. CONCLUSIONS: An important component of this work is the complication recording according to a uniform classification system (SAVES V2). In contrast to previous literature, we could demonstrate that there is not a significant difference between the two surgical techniques.

Could the different surgical goals of fusion and non-fusion also be achieved in combination within the same patient? Clinical and radiological outcome of hybrid cervical spine surgery.

PURPOSE: Hybrid cervical spine surgery (HS) is a novel surgical strategy wherein an artificial disc replacement is done with a cervical fusion nearby with a stand-alone titanium cage to combine the advantages in both procedures. The aim of this study was to evaluate interactions of these devices within the same patient, and to analyze, if the different goal of each implant is accomplished. METHODS: Thirty-six patients were treated surgically within a non-randomized retrospective study framework with HS. Patients were examined preoperatively followed by clinical and radiological examination at least one year postoperative. Clinical outcome was detected with NDI, VAS arm/neck, pain self-assessment questionnaires and subjective patient satisfaction. Radiological assessments included RoM, segmental lordosis, cervical lordosis of C2-C7, subsidence, ap-migration and heterotopic ossifications (HO) at the cTDR levels. RESULTS: Statistically significant improvement of all clinical scores was observed (NDI 37.5 to 5.76; VASarm 6.41 to 0.69; VASneck 6.78 to 1.48). Adequate RoM was achieved at cTDR levels. RoM in the ACDF levels was reduced statistically significant (p < 0.001), and solid fusion (> 2°) was achieved in all evaluated fusion level. Global lordosis (C2-C7) increased statistically significant (2.4° to 8.1°). Subsidence and HO at the cTDR levels did not occur. CONCLUSIONS: HS results in preservation of the segmental motion in the cTDR and fast and solid fusion in the cage cohort simultaneously. Patient safety was proven. In carefully selected cases, HS is a safe and viable treatment option by choosing the right "philosophy" level per level.

Influence of cervical total disc replacement on motion in the target and adjacent segments.

BACKGROUND CONTEXT: The motion limitation after cervical discectomy and fusion alters the spine´s kinematics. Unphysiological strains may be the result and possible explanation for adjacent segment degeneration. Alterations to cervical kinematics due to cervical total disc replacement (TDR), especially two-level, are still under investigated. PURPOSE: To investigate cervical motion including coupled motions after one-level and two-level TDR in the treated and also the adjacent segments. STUDY DESIGN: An in-vitro study using pure moment loading of human donor spines. METHODS: Seven fresh frozen human cervical spine specimens (C4-T1, median age 46 with range 19-60 years, four female) were included in this study. Specimens were tested in the intact condition first, followed by one-level TDR at C5-6 which was subsequently extended one level further caudal (C5-7). Each specimen was quasistatically loaded with pure moments up to 1.5 Nm in flexion/extension (FE), lateral bending (LB), and axial rotation (AR) in a universal spine tester for 3.5 cycles at 1 °/s. During the tests three dimensional motion tracking was performed for each vertebral body individually. From that, the primary and coupled ROM of each spinal level during the third full cycle of motion were evaluated. Nonparametric statistical analysis was performed using a Friedman-test and post hoc correction with Dunn-Bonferroni-tests (p<.05). Ethics approval was obtained in advance. RESULTS: In FE, one-level TDR (C5-6) moderately increased primary FE in all four segments, but only significantly at the cranial adjacent level C4-5. Additional TDR at C6-7 further increased the ROM at the target segment without much influence on the other levels. Increasing implant height at C6-7 partially counteracted the increased FE. Coupled motions were minimal in all test conditions at all levels. In LB, coupled AR was observed in all test conditions at all levels. One-level TDR decreased primary LB at the target segment C5-6 significantly, without much influence on the other levels. Extending TDR to C6-7 decreased ROM in the target segment but without gaining statistical significance. Increasing implant height at C6-7 further decreased primary LB at the target segment, still without significance. Notably, coupled AR was significantly decreased at the cranial adjacent segment C4-5 compared to the intact condition. In AR, coupled LB was observed in all test conditions at the levels C4-5, C5-6, and C6-7, while the transition level to the thoracic spine C7-T1 showed only little coupled LB. Both one-level and two-level TDR showed little influence on primary AR or coupled motions at any level. Only after increasing implant height at C6-7 was the motion of the caudally adjacent level C7-T1 significantly altered. CONCLUSION: Evaluating primary FE, LB, and AR together with the associated coupled motions revealed widespread influence of cervical TDR not only on the motion of the treated level but also at the adjacent segments. The influence of two-level TDR is more widespread and involves more levels than one-level TDR. CLINICAL SIGNIFICANCE: The prevention of unphysiological strains due to altered kinematics after cervical fusion, which could possibly explain adjacent segment degeneration, were a driving factor in the development of TDR. These experimental findings suggest cervical TDR influences the whole cervical spine, not only the treated segment. The effect becomes more extensive, involving more levels and motion directions, after two-level than after one-level TDR.

Full-endoscopic bilateral over-the-top decompression in lumbar central stenosis: surgical technique and outcomes.

Decompression of spinal stenosis represents one of the most commonly performed procedures in spine surgery. With constantly increasing patient age and changing demographics, reducing the invasiveness of surgical procedures has become increasingly important. Over the past decades, microsurgical decompression has been established as a gold standard technique for the surgical treatment of spinal stenosis. In comparison with open techniques or surgeries that were performed with loop lenses, which required larger skin incisions, and which consecutively raised the access-related collateral damage, the microscope served to significantly reduce the invasiveness of the decompression interventions. Advantages included smaller skin incisions, reduced collateral tissue damage, less blood loss, lower infection rates and wound healing problems, shorter hospital stay, and multiple others, as widely known across various MIS techniques. For the same reasons as outlined above, the introduction of full-endoscopic surgical techniques aims to further reduce the invasiveness of surgical interventions. The present manuscript provides a delineation of the surgical technique of LE-ULBD (Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression), gives an overview on the current state of literature, and aims to put this surgery into context with other currently available decompression techniques.

Computer-assisted simulated workplace-based assessment in surgery: application of the universal framework of intraoperative performance within a mixed-reality simulation.

Objectives: Workplace-based assessment (WBA) is a key requirement of competency-based medical education in postgraduate surgical education. Although simulated workplace-based assessment (SWBA) has been proposed to complement WBA, it is insufficiently adopted in surgical education. In particular, approaches to criterion-referenced and automated assessment of intraoperative surgical competency in contextualized SWBA settings are missing.Main objectives were (1) application of the universal framework of intraoperative performance and exemplary adaptation to spine surgery (vertebroplasty); (2) development of computer-assisted assessment based on criterion-referenced metrics; and (3) implementation in contextualized, team-based operating room (OR) simulation, and evaluation of validity. Design: Multistage development and assessment study: (1) expert-based definition of performance indicators based on framework's performance domains; (2) development of respective assessment metrics based on preoperative planning and intraoperative performance data; (3) implementation in mixed-reality OR simulation and assessment of surgeons operating in a confederate team. Statistical analyses included internal consistency and interdomain associations, correlations with experience, and technical and non-technical performances. Setting: Surgical simulation center. Full surgical team set-up within mixed-reality OR simulation. Participants: Eleven surgeons were recruited from two teaching hospitals. Eligibility criteria included surgical specialists in orthopedic, trauma, or neurosurgery with prior VP or kyphoplasty experience. Main outcome measures: Computer-assisted assessment of surgeons' intraoperative performance. Results: Performance scores were associated with surgeons' experience, observational assessment (Objective Structured Assessment of Technical Skill) scores and overall pass/fail ratings. Results provide strong evidence for validity of our computer-assisted SWBA approach. Diverse indicators of surgeons' technical and non-technical performances could be quantified and captured. Conclusions: This study is the first to investigate computer-assisted assessment based on a competency framework in authentic, contextualized team-based OR simulation. Our approach discriminates surgical competency across the domains of intraoperative performance. It advances previous automated assessment based on the use of current surgical simulators in decontextualized settings. Our findings inform future use of computer-assisted multidomain competency assessments of surgeons using SWBA approaches.

Predictive Parameters for Chêneau Brace Efficacy in Patients with Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective consecutive cohort study. OBJECTIVE: For patients with mild to moderate adolescent idiopathic scoliosis (AIS), bracing is the standard therapy to prevent progression of deformity. Still, not all patients benefit from treatment in the same way. Therefore, predictive parameters are needed to determine if patients are likely to benefit from brace therapy. METHODS: Fourty-five AIS patients treated with a Chêneau brace were evaluated retrospectively. Inclusion criteria were based on SRS-criteria. Whole spine X-rays were performed pre-brace, in-brace, and at least 6 months after termination of brace treatment. Gender, age, Risser's sign, vertebral rotation determined by Nash and Moe grading system, in-brace correction and in-brace time per day were parameters evaluated. Treatment success and failure groups were compared to determine possible predictive parameters for successful brace treatment. RESULTS: Chêneau brace treatment was successful preventing curve progression in 69%. We found significant differences between success and failure group concerning age (14 ± .22 vs 12.4 ± .4; P < .001) and Risser's sign (1.71 ± .16 vs .5 ± .17; P < .001) at beginning of brace treatment. Most significantly, initial in-brace curve correction was correlated with successful outcome after brace treatment (r = .64 (P < .001)). CONCLUSIONS: As one of few studies adhering to the criteria defined by the Scoliosis Research Society our study shows reliable predictive parameters for Chêneau brace treatment success in patients with AIS. Data shown in this paper will help to differentiate AIS patients who are likely to benefit from adequate bracing therapy from those who could rather benefit from early surgical treatment.

Radiological and Clinical Outcomes after Anterior Cervical Discectomy and Fusion (ACDF) with an Innovative 3D Printed Cellular Titanium Cage Filled with Vertebral Bone Marrow.

Objectives: To assess the clinical and radiological outcomes after ACDF with 3D printed cellular titanium cages filled with bone marrow and to compare the clinical and radiological results with the current scientific literature. Methods: ACDF was performed monosegmentally under standardized conditions. X-rays were analyzed to determine the range of motion, fusion rates, and subsidence preoperatively and 3 and 12 months postoperatively. Clinical outcome measurements included neck disability index (NDI), visual analogue scale (VAS) for brachialgia and cervicalgia, and patient satisfaction. Results: 18 patients were included in the study. The mean RoM decreased from 7.7° ± 2.6 preoperatively to 1.7° ± 1.1° after 3 months and 1.8° ± 1.2° 12 months after surgery. The fusion rates were at 94.4% after 3 and 12 months. The mean subsidence was 0.9 mm ± 0.5 mm 3 months postoperatively and 1.1 mm ± 0.5 mm 12 months after surgery. The mean NDI improved significantly from preoperatively to 12 months postoperatively (34.6 ± 6.2 and 3.4 ± 4.1, respectively). The VAS-neck also showed a large improvement from 5.8 ± 2.2 before and 1.3 ± 1.4 12 months after surgery, as did the VAS-arm (6.4 ± 1.5 and 0.9 ± 1.6, respectively). Patient satisfaction was high throughout the follow-up period. Conclusion: ACDF with a 3D printed titanium cage resulted in fast fusion without pathological subsidence. In comparison to other cage materials such as PEEK, the 3D printed titanium cage was noninferior in regard to its fusion rate and clinical results.

Differences in the Exposure of the Lumbar Nerve Root Between Experts and Novices: Results From a Realistic Simulation Pilot Study With Force Sensors.

STUDY DESIGN: Nonrandomized prospective trial. OBJECTIVE: Several studies could demonstrate "learning curves" in almost every single surgical procedure for unexperienced surgeons. This is in sharp contrast to the rising quality requirements in public health care to provide surgical training at patients "expense." The aim of this study was to visualize, measure, and set a baseline of the pressure load on the spinal nerve root during a simulated microdiscectomy on a standardized and validated model (RealSpine) under the influence of the level of surgical experience and individual skills. METHODS: Five highly experienced spine surgeons and 5 trainees without considerable surgical experience were selected to perform a standardized microsurgical discectomy on a validated RealSpine simulator. Force-torque sensors were integrated in this simulator to measure the load on the nerve root. The forces were recorded every 125 ms. RESULTS: We could identify cumulative for the total intervention as well as for defined single surgical steps of this procedure and as well in between the single subjects a significant higher tension and contusion forces on the nerve for the trainee group (Δp contusion 83-765 Ncs and Δp tension 159-1131 Ncs for the trainees. Δp contusion 16-171 Ncs and Δp tension 27-146 Ncs for the experts). CONCLUSION: We could measure a difference between unexperienced and experienced surgeons regarding the manipulations of the nerve root during a standardized simulated microdiscectomy. This possibility could be the starting point for a new and innovative surgical education to improve outcome without negative side effects of "learning curves."

[The mono- and multisegmental ventral minimally invasive approach to the lumbar spine (OLIF) in lumbar deformities]. / Mono- und mehrsegmentaler ventraler minimalinvasiver Zugang zur Lendenwirbelsäule (OLIF) zur Korrektur von Deformitäten.

OBJECTIVE: Minimally invasive anterolateral approach to the lumbar spine (oblique lateral interbody fusion, OLIF) to correct lumbar deformities. INDICATIONS: Ventral release in degenerative lumbar scoliosis or segmental kyphosis and intervertebral spondylodesis. CONTRAINDICATIONS: No absolute contraindications. Relative contraindications are previous (left-sided) retroperitoneal interventions or status after peritonitis with pronounced retroperitoneal scarring. Vascular anomalies with extremely lateral common iliac vein (especially with segmentation disorders in the penultimate mobile segment). SURGICAL TECHNIQUE: Through a small skin incision in the left abdominal wall and alternating incision technique through the abdominal wall muscles retroperitoneal approach to the lateral anterior lumbar spine monosegmental or from L1-L5 multisegmental if needed. Retraction of the psoas muscle and removal of the intervertebral disc space, if necessary with resection of the anterior longitudinal ligament. Intervertebral release and interposition of an implant for ventral spondylodesis. POSTOPERATIVE MANAGEMENT: Early mobilisation after dorsal instrumentation under thrombosis prophylaxis. Light meals until the first bowel movement. Wearing a trunk stabilizing brace for up to 12 weeks, depending on the type and extent of the procedure. No limitations regarding walking distance, standing and sitting immediately postoperatively. RESULTS: In all, 15 patients with degenerative lumbar scoliosis were treated with ventrodorsal fusion surgery. The surgical anterior treatment included 1-4 segments. The access-specific complications and pre- and postoperative radiological parameters were recorded. None of the 15 left-sided retroperitoneal ventral accesses showed intraoperative or postoperative access-specific complications. A significant reduction of the anteroposterior Cobb angle from 16°â€¯± 6° preoperatively to 3°â€¯± 2° postoperatively (p < 0.001) was achieved in the entire patient population.

[The Facet Wedge: a minimally invasive technique for posterior segmental intra-articular fusion]. / Facet Wedge: eine minimalinvasive Technik zur dorsalen segmentalen intraartikulären Fusion.

OBJECTIVE: Minimally invasive posterior segmental instrumentation and intra-articular fusion with the Facet Wedge device. INDICATIONS: All fusion indications in degenerative disc disease without significant translational instability, postnucleotomy syndrome, spondylarthrosis, discitis. CONTRAINDICATIONS: Translatory instabilities, status after decompression with partial facet joint resection, spondylolysis in the affected segment. SURGICAL TECHNIQUE: Through a 3 cm skin incision, blunt transmuscular approach to the corresponding facet joint L1/2 to L5/S1. Opening of the joint capsule and visualisation of the intra-articular space. Cartilage removal and intra-articular implantation of the Facet Wedge device. Fixation of the implant by means of two angle-stable screws inserted in the corresponding facet joint parts. POSTOPERATIVE MANAGEMENT: Early mobilisation under thomboprophylaxis. Wearing a trunk-stabilizing brace for up to 12 weeks, depending on the type and extent of the procedure. No restrictions regarding walking distance, standing and sitting immediately postoperatively after pain. RESULTS: In all, 27 patients (mean age 51.2 years, range 30-76 years) were enrolled in the prospective nonrandomized study from 02/2015 to 9/2017 with a total of 31 treated segments. In 23 cases a ventrodorsal surgical technique was used, in 4 cases a purely dorsal procedure with interposition of an intervertebral cage. Follow-up was 2 years. The Oswestry Score (ODI) improved from an average of 40.6% preoperatively to 16.6% postoperatively. The visual analog scale (VAS) for back pain improved from an average of 6.7 points preoperatively to 2.1 points 2 years postoperatively. During this observation period, 2 implant-specific complications were observed. One Facet Wedge had to be revised due to misplacement with early loosening. In another case, loss of correction occurred in a preoperatively existing first-degree spondylolisthesis with revision to a dorsal screw-rod system.

Revision after failed discectomy.

PURPOSE: Recurrent lumbar disc herniation is the most common complication after discectomy. Due to the altered anatomy with the presence of scar tissue, the surgical revision of already operated patients could be a surgical challenge. METHODS: We describe the microsurgical revision technique step by step with the evaluation of our own clinical results in comparison with primary lumbar disc surgeries. The clinical data are based on a clinical register with 2576 recorded primary surgeries (PD) and 592 cases of revisions (RD) with 12- and 24-month follow-up (FU). The intraoperative dura lesion rates of the surgeries between 2016 and 2018 were recorded retrospectively. Data from 894 primary disc surgeries and 117 revisions were evaluated. RESULTS: The ODI and the VAS for leg and back pain improved in both groups significantly with slightly inferior outcome of the revision group. The ODI improved from 46.3 (PD) and 45.9 (RD), respectively, to 12.6 (PD) and 22.9 (RD) at the 24-month FU. The VAS dropped down as well in both group [VAS back: 47.8 (PD) and 43.9 (RD) to 19.9 and 32.2 at the 24-month FU; VAS leg: 62.9 (PD) and 65.5 (RD) to 15.6 and 26.8 at the 24-month FU]. During the primary interventions, we observed 1.5% (11/894) and during revisions 7.7% (9/117) of dura lesions. CONCLUSIONS: There is no clear guideline for the surgical treatment of recurrent disc herniations. In most cases, a pure re-discectomy is sufficient and can be performed safely and effectively with the help of a microscope. These slides can be retrieved under Electronic Supplementary Material.

Technical and Nontechnical Skills in Surgery: A Simulated Operating Room Environment Study.

STUDY DESIGN: Observational simulation study. OBJECTIVE: The goal of this study was to investigate the relationship between technical and nontechnical skills (NTS) in a simulated surgical procedure. SUMMARY OF BACKGROUND DATA: Although surgeons' technical and NTS during surgery are crucial determinants for clinical outcomes, little literature is available in spine surgery. Moreover, evidence regarding how surgeons' technical and NTS are related is limited. METHODS: A mixed-reality and full-scale simulated operating room environment was employed for the surgical team. Eleven surgeons performed the vertebroplasty procedure (VP). Technical skills (TS) were assessed using Objective Structured Assessment of Technical Skill scores and senior expert-evaluated VP outcome assessment. NTS were assessed with the Observational Teamwork Assessment for Surgery. Kendall-Tau-b tests were performed for correlations. We further controlled the influence of surgeons' experience (based on professional tenure and number of previous VPs performed). RESULT: Surgeons' NTS correlated significantly with their technical performance (τ = 0.63; P = 0.006) and surgical outcome scores (τ = 0.60; P = 0.007). This association was attenuated when controlling for surgeons' experience. CONCLUSION: Our results suggest that spine surgeons with higher levels of TS also apply better communication, leadership, and coordination behaviors during the procedure. Yet, the role of surgeons' experience needs further investigation for improving surgeons' intraoperative performance during spine surgery. LEVEL OF EVIDENCE: 3.

Implant Design and the Anchoring Mechanism Influence the Incidence of Heterotopic Ossification in Cervical Total Disc Replacement at 2-year Follow-up.

STUDY DESIGN: A nonrandomized, prospective, and single-center clinical trial. OBJECTIVE: The aim of this study was to determine whether the prosthesis design, and especially changes in the primary anchoring mechanism between the keel-based ProDisc C and the spike-based ProDisc Vivo, affects the frequency of heterotopic ossification (HO) formation over time. SUMMARY OF BACKGROUND DATA: The occurrence of motion-restricting HO as well as underlying risk factors has so far been a widely discussed, but not well understand phenomenon. The anchoring mechanism and the opening of the anterior cortex may be possible causes of this unwanted complication. METHODS: Forty consecutive patients treated with the ProDisc C and 42 consecutive patients treated with the ProDisc Vivo were compared with respect to radiological and clinical outcome, with 2 years of follow-up. Clinical outcome scores included the Neck Disability Index (NDI), Visual Analogue Scale (VAS), and arm and neck pain self-assessment questionnaires. Radiological outcomes included the segmental lordosis and range of motion (ROM) of the index-segment as well as the occurrence of HO. RESULTS: The clinical outcome parameters improved in both groups significantly. [ProDisc C: VAS arm and neck pain from 6.3 and 6.2 preoperatively to 0.7 and 1.3; NDI from 23.0 to 3.7; ProDisc Vivo: VAS arm and neck pain from 6.3 and 4.9 to 1.4 and 1.6, NDI from 34.1 to 8.7; 2-year follow-up (FU)]. The ProDisc Vivo cohort demonstrated a significantly lower incidence of HO than the ProDisc C group at 1-year FU (P = 0.0005) and 2-year FU (P = 0.005). Specifically, high-grade HO occurred in 9% versus 31%. CONCLUSION: These findings demonstrate that prosthesis designs that allow primary anchoring without violation of the cortical surface help to reduce the incidence of severe ossification, possibly affecting the functionality and mobility of the artificial disc device over of time. LEVEL OF EVIDENCE: 3.

Clinical and Radiographic Outcome of Patients With Cervical Spondylotic Myelopathy Undergoing Total Disc Replacement.

STUDY DESIGN: A nonrandomized, prospective, and single-center clinical trial. OBJECTIVE: The aim of this study was to investigate the clinical and radiographic efficacy of ProDisc Vivo cervical total disc replacement (cTDR) in patients with clinical and radiographic documented cervical spondylotic myelopathy (CSM), due to degenerative changes at the index level. SUMMARY OF BACKGROUND DATA: Decompression and fusion is still the gold standard in patients with cervical myelopathy. Very limited data are available regarding the application of cTDR in patients with clinical and radiological documented CSM in context of clinical and radiographic outcomes. METHODS: Clinical outcome scores included the Neck Disability Index (NDI), Visual Analogue Scale (VAS), arm and neck pain self-assessment questionnaires as well as the Nurick grade and the Japanese Orthopaedic Association (JOA) score. The radiological outcome included the range of motion (ROM), the segmental and global (C2-C7) lordosis, and the occurrence of heterotopic ossifications. RESULTS: Eighteen consecutive patients (10 males, 8 females) with documented clinical and radiological signs of myelopathy were included in this investigation. The study population had a mean age of 52.4 years and a follow-up period of 20.3 months in average (range 3-48 months). The mean range ROM of the index level stayed consistent with 6.8° preoperatively and 7.2° (P = 0.578) at the last follow-up; the global lordosis in neutral position changed from 3.5° to 14.2° significantly (P = 0.005) in mean. The JOA score improved from 11.3 to 16.6 (P < 0.001) as well as the NDI 36.7 to 10.3 (P < 0.001) and the VAS score from 5.7/6.1 (arm/neck) to 1.3/2.0 (P < 0.001/P < 0.001). The mean Nurick grade was 1.33 preoperatively and dropped down in all cases to Nurick grade of 0 (P < 0.001). CONCLUSION: cTDR (with ProDisc Vivio) in patients with CSM yielded good clinical and radiographic outcomes and found as a reliable, safe, and motion-preserving surgical treatment option, although its indication is very limited due to numerous exclusion criteria. LEVEL OF EVIDENCE: 4.

Clinical and Radiological Outcome of a New Total Cervical Disc Replacement Design.

STUDY DESIGN: A nonrandomized, prospective, and single-center clinical trial of the ProDisc Vivo prosthesis. OBJECTIVE: The aim of this study was to investigate the clinical and radiological results of a refined total cervical disc replacement (cTDR), the ProDisc Vivo, with two years of follow-up (FU). The incidence of implant-related complications was recorded as a secondary outcome variable. SUMMARY OF BACKGROUND DATA: Previous generations of the ProDisc artificial cervical disc replacement generate high primary stability due to keel-based designs with opening of the anterior cortex during the implantation and subsequent high rates of heterotopic ossifications. METHODS: Clinical outcome scores included the Neck Disability Index (NDI), Visual Analogue Scale (VAS), arm and neck pain self-assessment questionnaires. The radiological outcome included the range of motion (ROM) and the occurrence of heterotopic ossifications. The incidence of implant-related complications with new implant design was recorded as a secondary outcome variable. RESULTS: A total of 55 patients received a single-level treatment with the ProDisc Vivo cTDR between C3/4 and C6/7, with a follow-up rate of 78%. The clinical outcome scores improved in all parameters significantly (P = 0.0001) (NDI: 68.3 → 17.4; VAS arm: 6.3 → 1.4; VAS neck: 4.9 → 1.6). The ROM of the index-segment did not show a significant change (P = 0.26) (7.9° → 9.2°). Heterotopic ossifications at the index segment was found as grade 0 in 58%, grade 1 in 22%, grade 2 in 10%, grade 3 (with functional impairment of the prosthesis) in 7%, and grade 4 in 3% of the cases. We observed three implant-related complications (5.5%), with two implant dislocations anteriorly and one low-grade infect. CONCLUSION: cTDR with ProDisc Vivo demonstrated a significant and sustained improvement of all clinical outcome parameters. A less invasive implantation mechanism with lower primary stability of the cTDR might be a reason for a higher dislocation rate than the keel-based previous generation ProDisc C. LEVEL OF EVIDENCE: 4.

Clinical and radiological outcome at 10 years of follow-up after total cervical disc replacement.

PURPOSE: Previous studies have demonstrated that total cervical disc replacement (cTDR) represents a viable treatment alternative to the 'gold standard' anterior cervical discectomy and fusion for the treatment of well-defined cervical pathologies at short- and mid-term follow-up (FU). However, the implementation and acceptance of a non-fusion philosophy is closely associated with its avoidance of adjacent segment degeneration. Proof of the functional sustainability and clinical improvement of symptoms at long-term FU is still pending. The aim of this ongoing prospective study was to investigate the clinical and radiological results of cTDR at long-term FU. METHODS: 50 patients were treated surgically within a non-randomised prospective study framework with cTDR (ProDisc C™, Synthes, Paoli, PA, USA). Patients were examined preoperatively followed by routine clinical and radiological examinations at 1, 5 and 10 years after surgery, respectively. In addition to the clinical scores, conventional X-ray images of the cervical spine were taken in anteroposterior and lateral view as well as flexion/extension images. Clinical outcome scores included parameters such as the Neck Disability Index (NDI), Visual Analogue Scale (VAS), arm and neck pain self-assessment questionnaires as well as subjective patient satisfaction rates. The radiological outcome variables included the range of motion (ROM) of the implanted prosthesis between maximum flexion and extension images, the occurrence of heterotopic ossifications and radiographic signs of adjacent segment degenerative changes. The reoperation rate following cTDR was recorded as a secondary outcome variable. RESULTS: A significant and maintained clinical improvement of all clinical outcome scores was observed after a mean FU of 10.2 years (VASarm 6.3-2.1; VASneck 6.4-1.9; NDI 21-6; p < 0.05). An increase in the incidence and the extent of heterotopic ossifications was noted during the post-operative course with a significant influence on the function of the prosthesis, which, however, did not reveal any detrimental effect on the patients' clinical symptomatology. Prosthesis mobility declined from 9.0° preoperatively and 9.1° at 1 year FU to 7.7° and 7.6° at the five- and ten-year FU examinations, respectively. Radiological signs of adjacent segment degeneration were detected in 13/38 (35.7%), however, in only 3/38 (7.9%) patients this radiological changes were associated with clinical symptoms requiring conservative treatment. Intraoperative technical failure in two cases required interbody fusion with a cage (2/50). One patient (1/48, 2.1%) treated this motion device had revision surgery at the index level. CONCLUSION: Cervical total disc replacement with ProDisc C demonstrated a significant and maintained improvement of all clinical outcome parameters at a follow-up of ≥10 years. The present long-term data reveal that with an exceptionally low implant-related reoperation rate and low symptomatic adjacent segment degeneration rate, cTDR may be regarded as a safe and viable treatment option.