Titanium-coated Polyetheretherketone Research Articles

Titanium-Coated Polyetheretherketone Cages Vs Full Titanium Cages for Stand-Alone 1- or 2-Level Anterior Cervical Discectomy and Fusion: A Comparative Study.

Anterior cervical discectomy and fusion (ACDF) for the surgical treatment of cervical degenerative disease often includes an intervertebral cage, which restores disc height and lordosis while promoting fusion . Cage materials include titanium (TTN) or polyetheretherketone (PEEK). Controversy in material selection stems from higher fusion rates with TNN, despite a higher subsidence rate, while PEEK cages demonstrate superior preservation of interspace height. Combining the advantages of both materials, TTN-coated PEEK (TCPEEK) cages were developed, featuring a PEEK core with similar stiffness to the bone, enveloped with a TTN coat, improving osteointegration. However, the potential superiority of TCPEEK over TTN cages has not been investigated. This study aimed to compare clinical and radiographic outcomes following single- or double-level ACDF using either TTN or TCPEEK cages. This retrospective single-center study included patients undergoing single- or double-level ACDF between 2017 and 2019. Clinical outcomes included the Neck Disability Index and revision surgery incidence. Radiographic parameters included cervical and segmental lordosis, C2 to C7 sagittal vertical axis, fusion, subsidence, and adjacent segment degeneration at a minimum 12-month follow-up. A total of 45 patients (16 TTN; 29 TCPEEK) and 58 cervical levels (21 TTN; 37 TCPEEK) were included. Both cages significantly improved Neck Disability Index scores (TTN -10.0; TCPEEK -14.1) without significant differences. Two single-level TCPEEK patients required revision surgery due to non-union. In the radiological assessments, no significant difference was found for subsidence rates (TTN 52.4%; TCPEEK 56.8%), adjacent segment degeneration, cervical and segmental lordosis, and changes in C2 to C7 sagittal vertical axis. Though not statistically significant, fusion rates trended slightly higher with TTN (90.5%) vs TCPEEK cages (86.5%). TTN and TCPEEK cages achieve satisfactory clinical and radiological outcomes in single- or double-level ACDF. This finding suggests that the choice between them can be based on other factors, such as surgeon preference or availability, rather than specific material properties. This study found that the selection of ACDF cage material did not affect clinical outcomes.

The Influence of Titanium-coated Poryetheretherketone Cages in Fusion Status after Posterior Lumbar Interbody Fusion with Cortical Bone Trajectory Screw Fixation

Posterior lumbar interbody fusion (PLIF) with cortical bone trajectory (CBT) screw fixation (CBT-PLIF) shows potential for reducing adjacent segmental disease. Previously, our investigations revealed a relatively lower fusion rate with the use of carbon fiber-reinforced polyetheretherketone (CP) cages in CBT-PLIF compared with traditional pedicle screw fixation (PS-PLIF) using CP cages. This study aims to evaluate whether the implementation of titanium-coated polyetheretherketone (TP) cages can enhance fusion outcomes in CBT-PLIF. A retrospective analysis was conducted on 68 consecutive patients who underwent CBT-PLIF with TP cages (TP group) and 89 patients who underwent CBT-PLIF with CP cages (CP group). Fusion status was assessed using computed tomography at 1 year postoperatively and dynamic plain radiographs at 2 years postoperatively. No statistically significant differences in fusion rates were observed at 1 and 2 years postoperatively between the TP group (86.8% and 89.7%, respectively) and the CP group (77.5% and 88.8%, respectively). Notably, the CP group exhibited a significant improvement in fusion rate from 1 to 2 years postoperatively (P= 0.002), while no significant improvement was observed in the TP group. Examination of temporal changes in fusion rates reveals that only the TP group achieved a peak fusion rate 1 year postoperatively. This implies that TP cages may enhance the fusion process even after CBT-PLIF. Nevertheless, the definitive efficacy of TP cages for CBT-PLIF remains uncertain in the context of overall fusion rates.

Trabecular Bone Remodeling After Posterior Lumbar Interbody Fusion: Comparison of Three-Dimensional Porous Tantalum and Titanium-Coated Polyetheretherketone Interbody Cages.

Retrospective cohort study. The criteria for determining completion of intervertebral stability after posterior lumbar interbody fusion (PLIF) remain controversial. Several new radiological indicators of bone growth and osteointegration have been established. We compared computed tomography (CT) findings related to osteointegration after PLIF with interbody cages of two different materials and designs. We retrospectively analyzed data from 103 patients who underwent PLIF with three-dimensional porous tantalum (Tn) cages or titanium-coated polyetheretherketone (TiP) cages. CT images obtained 3months and 1year after surgery were examined for trabecular bone remodeling (TBR), cancellous condensation (CC), and vertebral endplate cyst (VEC) formation. The incidences of each finding were compared by cage type, and rates of instrument failure and pseudarthrosis were determined. Three months postoperatively, 87% of the levels with Tn cages exhibited TBR, whereas 96% of those with TiP cages did not (P < .001). Most levels with Tn cages levels exhibited TBR and no CC 3months (81%) and 1 year (94%) after surgery. Although 78% of levels with TiP cages exhibited CC and no TBR 3months after surgery, 59% exhibited both CC and TBR 1 year after surgery. Significantly fewer VECs formed around the Tn cages than around the TiP cages both 3months (P = .002) and 1year (P < .001) after surgery. Implant-related problems occurred at levels that exhibited neither TBR nor CC. The porous tantalum cage may enable intervertebral stability that is comparable to bony fusion soon after surgery.

A Comparison of Polyetheretherketone and Titanium-Coated Polyetheretherketone in Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Randomized Clinical Trial

To compare patient-reported outcomes and radiographic outcomes between using polyetheretherketone (PEEK) and titanium-coated PEEK (TiPEEK) as an interbody cage in patients who underwent minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Eighty-Six patients who underwent 1-2 levels of MIS-TLIF were randomly allocated to receive a TiPEEK or PEEK cage. Patient-reported outcomes were recorded using visual analog scale, Oswestry Disability Index, and EuroQoL-5D-5L. Postoperative radiographs and computed tomography were assessed for spinal fusion and cage subsidence. The eligible 82 patients (41 patients, 49 operated levels in TiPEEK group and 41 patients, 50 operated levels in PEEK group) were included in the final analysis. Over total follow-up, the mean difference in visual analog scale back and leg pain scores between TiPEEK versusPEEK group was-0.04 (95% confidence interval [CI],-0.5 to 0.4; P= 0.85) and-0.12 (95% CI,-0.6 to 0.3; P= 0.62), respectively. The mean difference in Oswestry Disability Index scores was-0.71 (95% CI,-3.8 to 2.4; P= 0.65), and the mean difference in EQ-5D-5L was 0.03 (95% CI,-0.01 to 0.06; P= 0.11) in TiPEEK group versus PEEK group as a reference. TiPEEK showed significantly higher fusion rates than PEEK at 6-month (91.8% vs. 76%; P= 0.03), but no difference at 12-month postoperation. There was no significant difference in cage subsidence rates between the 2 groups. The patient-reported outcomes showed significant improvements at 6- and 12-month postoperation following MIS-TLIF; the differences in those with TiPEEK versus PEEK cages were minimal with tight CIs. Fusion rates in both groups were ≥90%, with TiPEEK cages showing higher fusion rates at 6months after the procedure.

Titanium-coated PEEK Versus Uncoated PEEK Cages in Lumbar Interbody Fusion: A Systematic Review and Meta-analysis of Randomized Controlled Trial.

Systematic review and meta-analysis. This study was performed to compare the fusion and subsidence rate of titanium-coated polyetheretherketone (Ti-PEEK) versus polyetheretherketone (PEEK) cages after lumbar fusion and to investigate the clinical effect on patient-reported outcomes (PROMs). Ti-PEEK cages have been developed to combine the advantages of both titanium alloy and PEEK, but whether they are superior to uncoated PEEK cages in bone fusion is still inconclusive. PubMed, EMBASE, ISI Web of Science, CENTRAL, and CNKI were searched to identify randomized controlled trials that compared the efficacy of Ti-PEEK and PEEK cages in lumbar fusion. Difference in fusion rate and subsidence rate was indicated by risk ratio and its associated 95% confidence interval (95% confidence interval). Mean difference was calculated for Oswestry Disability Index and visual analogue scale for low back pain. Subgroup analysis was performed by time course after the surgery. The Grading of Recommendations, Assessment, Development and Evaluation approach was used to evaluate the certainty of evidence. Four randomized controlled trials involving 325 patients (160 patients in Ti-PEEK group and 165 patients in PEEK group) that underwent lumbar fusion were included by our current study. Low to moderate evidence suggested that Ti-PEEK and PEEK cages exhibited equivalent fusion rate and subsidence rate at any follow-up time. Low to moderate evidence suggested that there was no difference in PROMs except for visual analogue scale measured at 6 months (mean difference: -0.57, 95% confidence interval -0.94, -0.21; P =0.002) but the difference was not clinically relevant according to the minimal clinically important difference. Low to moderate evidence showed that Ti-PEEK and PEEK had equivalent effect in bone fusion and cages subsidence at any follow-up time after lumbar fusion surgeries. Low to moderate evidence showed no clinically important difference in PROMs.

Subsidence following cervical discectomy and implant-to-bone ratio

BackgroundImplant subsidence is an undesirable effect after anterior cervical discectomy and fusion (ACDF). We investigated the relation between the rate of implant subsidence and the ratio of the implant surface area to the surface area of the adjacent bone.MethodsWe operated 170 disc spaces in a group of 104 patients. Two types of implants were used: 1) PEEK (polyetheretherketone) cages and 2) titanium-coated (TC) PEEK cages. Patients were randomised to receive a specific implant using a randomisation table. All implants had a surface area of 1.61 cm2. Based on computed tomography images, bone surface areas were calculated for vertebral bodies immediately adjacent to the interbody implants. The implant-to-bone surface ratio was then calculated for each disc space. Implant subsidence was assessed over 12 months of follow-up, and associations between implant subsidence, the type of implant, and the implant-to-bone surface ratio were investigated.ResultsTwelve months after the surgery, computed tomography was performed on 86 patients (144 disc spaces). Furthermore, in 166 disc spaces and 102 patients, conventional radiographs were obtained.Subsidence was observed in 21% of the examined intervertebral spaces, and it was more frequently associated with higher values of bone surface area and lower values of the implant-to-bone surface ratio. The type of implant (PEEK vs TC-PEEK cages) did not significantly influence the rate of implant subsidence.ConclusionsImplant subsidence was significantly related to the value of a coefficient representing the ratio of the implant's surface area to the bone surface area of the adjacent vertebral bodies, with subsidence occurring significantly more rarely for coefficient values ≥ 0.37.

Concepts, Rationale, and Techniques of the Open Approach in the Surgical Management of Metastatic Spine Disease

Advancements in medical therapy have led to the increased incidence of metastatic spine tumor surgery (MSTS) owing to the increased survivability of cancer patients. Over the years, surgical techniques have evolved from simple laminectomy to advanced radical surgery with reconstruction. Surgery with radiotherapy (RT) and chemotherapy have been established as key paradigms for the management of metastatic spine disease (MSD). In general, surgical treatment is split into two categories, open and minimally invasive. Decompression and stabilization form the basis of the common surgical techniques for managing MSD. Pedicle screw-rod instrumentation forms the basis of fixation, whereas decompression can be achieved through techniques such as laminectomy, separation surgery, partial corpectomy, near piecemeal corpectomy, or en bloc corpectomy. However, complications such as infection, wound dehiscence, and instrument failure remain the challenges of MSTS. This gives the need for auxiliary techniques and advancements to improve the efficacy of MSTS and reduce complications. Recent advancements such as intraoperative cell salvage in MSTS have reduced the need for allogenic blood transfusion, thus reducing the risk of infection and other complications. Additionally, implant materials such as carbon-fiber-reinforced polyether–ether-ketone (PEEK) and titanium-coated PEEK with better biocompatibility, imaging, and RT compatibility have been explored for use in MSTS. Current trends in MSTS are shifting toward minimally invasive surgery (MIS); however, open surgery remains the “gold standard.” Open surgery is preferred in cases with compromised visibility, i.e., hypervascular tumor secondaries and in regions of spinal column with limited access where the MIS approach is likely to be dangerous. We recommend that all spine surgeons be familiar with the concepts and techniques of open surgery for MSD.

Transforaminal Fusion Using Physiologically Integrated Titanium Cages with a Novel Design in Patients with Degenerative Spinal Disorders: A Pilot Study

More contemporary options have been presented in the last few years as surgical methods and materials have improved in patients with degenerative spine illnesses. The use of biologically integrated titanium cages of a unique design based on computer 3D modeling for the surgical treatment of patients with degenerative illnesses of the spine’s intervertebral discs has been proposed and experimentally tested. The goal of this study is to compare the radiographic and clinical outcomes of lumbar posterior interbody fusion with a 3D porous titanium alloy cage versus a titanium-coated polyetheretherketone (PEEK) cage, including fusion quality, time to fusion, preoperative and postoperative patient assessments, and the presence, severity, and other side effect characteristics. (1) Methods: According to the preceding technique, patients who were operated on with physiologically integrated titanium cages of a unique design based on 3D computer modeling were included in the study group. This post-surveillance study was conducted as a randomized, prospective, interventional, single-blind, center study to look at the difference in infusion rates and the difference compared to PEEK cages. The patients were evaluated using CT scans, Oswestry questionnaires (every 3, 6, and 12 months), and VAS scales. (2) Results: Six months following surgery, the symptoms of fusion and the degree of cage deflation in the group utilizing the porous titanium 3D cage were considerably lower than in the group using the PEEK cage (spinal fusion sign, p = 0.044; cage subsidence, p = 0.043). The control group had one case of cage migration into the spinal canal with screw instability, one case of screw instability without migration but with pseudoarthrosis formation and two surrounding segment syndromes with surgical revisions compared with the 3D porous titanium alloy cage group. (3) Conclusions: The technique for treating patients with degenerative disorders or lumbar spine instability with aspects of neural compression utilizing biologically integrated titanium cages of a unique design based on computer 3D printing from CT scans has been proven. This allows a new approach of spinal fusion to be used in practice, restoring the local sagittal equilibrium of the spinal motion segment and lowering the risk of pseudarthrosis and revision surgery.

PEEK versus titanium-coated PEEK cervical cages: fusion rate.

Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed procedures for degenerative cervical disease. The evaluation of fusion status is still not fully standardized, and a variety of measurement methods are used. This study presents our own evaluation of fusion by comparing two types of implants. A total of 170 disc spaces were operated on in 104 patients using PEEK (polyetheretherketone) cages and titanium-coated (TC) PEEK cages. Patients were assigned to a specific implant using a randomisation table. Fusion status was evaluated based on functional radiographs and CT scans obtained at 12months post-surgery. Multivariate mixed-effects logistic regression models were performed to assess the association of type of implant with different fusion rates. At 12months post-surgery, CT scans were performed in 86 patients (a total of 144 disc spaces) and conventional radiographs were obtained in 102 (a total of 166 disc spaces). Complete fusion was demonstrated in 101 cases (71.1%), partial fusion in 43 cases (29.9%). There were no cases of absence of fusion. A total of 85 PEEK cages (59%) and 59 TC-PEEK cages (41%) were implanted. For PEEK cages, complete fusion was seen in 75 (88.2%) disc spaces, compared to 26 (44.1%) achieved with TC-PEEK cages. A significantly higher proportion of complete fusions (B = 15.58; P < 0.0001) after 12months was observed with PEEK implants compared to TC-PEEK implants. Complete fusion was noted at 12months post-surgery significantly more frequently with PEEK implants compared to TC-PEEK implants.

Surgical outcomes after posterior lumbar interbody fusion using traditional trajectory screw fixation or cortical bone trajectory screw fixation: A comparative study between the polyetheretherketone cage and the same shape titanium-coated polyetheretherketone cage

ObjectiveTo investigate whether or not the fusion rate after posterior lumbar interbody fusion with cortical bone trajectory screw fixation (CBT-PLIF) is lower than after PLIF using traditional trajectory screw fixation (TT-PLIF) and whether or not the titanium-coated polyetheretherketone (PEEK) cage (TiP cage) improves fusion status compared to the same shape uncoated PEEK cage (P cage). MethodsThe subjects were 37 patients undergoing TT-PLIF using P cages (P-TT group), 24 patients undergoing CBT-PLIF using P cages (P-CBT group), 32 patients undergoing TT-PLIF using TiP cages (TiP-TT group), and 20 patients undergoing CBT-PLIF using TiP cages (TiP-CBT group). All patients from the 4 groups underwent our unified PLIF procedure (total facetectomy, subtotal discectomy, and the same bone graft technique using the same shape cages) except for the screw trajectories and the surface materials of the cages. Clinical symptoms were assessed using the Japanese Orthopedic Association (JOA) score before surgery and at 2-year postoperatively. None of age at the time of surgery, gender, fused segment and preoperative JOA score showed significant differences among the 4 groups. On multiplanar reconstruction computed tomography (MPR-CT) at 6months after surgery, vertebral end plate cysts were evaluated and classified into local or diffuse cysts. Fusion status was assessed using both dynamic plain radiographs and MPR-CT at postoperative 2-year. ResultsNeither the mean JOA score nor the mean recovery rate of the JOA score at 2-year after surgery showed significant differences among the 4 groups. The incidence of the diffuse cyst (a known predictor of non-union) was 27.0% in the P-TT group, 29.2% in the P-CBT group, 25.0% in the TiP-TT group and 25.0% in the TiP-CBT group (P > 0.05). The fusion rate was 89.2% in the P-TT group, 91.7% in the P-CBT group, 90.6% in the TiP-TT group and 90.0% in the TiP-CBT group (P > 0.05). ConclusionsAfter our unified PLIF procedure except for the screw trajectories and the surface materials of the cages, CBT-PLIF resulted in the equivalent fusion rate to TT-PLIF and the TiP cage did not lead to the improved fusion rate compared to the same shape P cage.

Early Fusion Status After Posterior Lumbar Interbody Fusion With Cortical Bone Trajectory Screw Fixation or Traditional Trajectory Screw Fixation: A Comparison Between the Titanium-coated Polyetheretherketone Cage and the Same Shape Polyetheretherketone Cage.

A retrospective analysis of prospectively collected data. The aim was to examine whether posterior lumbar interbody fusion with cortical bone trajectory screw fixation (CBT-PLIF) is inferior to PLIF using traditional trajectory screw fixation (TT-PLIF) regarding early fusion status and whether the titanium-coated polyetheretherketone (PEEK) cage (TP cage) improves early fusion status compared with the same shape pure PEEK cage (P cage). We recently reported that the fusion rate was relatively lower after CBT-PLIF than after TT-PLIF, although no significant difference was found and that compared with the carbon PEEK cage, the TP cage significantly reduced the incidence of vertebral endplate cysts (cyst signs) and slightly improved the early fusion rate at 1 year after CBT-PLIF. The subjects were 37 patients undergoing TT-PLIF using P cages (TT-P group), 24 patients undergoing CBT-PLIF using P cages (CBT-P group), 32 patients undergoing TT-PLIF using TP cages (TT-TP group), and 20 patients undergoing CBT-PLIF using TP cages (CBT-TP group). On multiplanar reconstruction computed tomography at 6 months after surgery, cyst signs were evaluated and classified into diffuse or local cysts. Early fusion status was assessed using both dynamic plain radiographs and multiplanar reconstruction computed tomography at 1-year postoperatively. The incidence of the diffuse cyst was 27.0% in the TT-P group, 29.2% in the CBT-P group, 25.0% in the TT-TP group and 25.0% in the CBT-TP group (P>0.05). The early fusion rate was 75.7% in the TT-P group, 75.0% in the CBT-P group, 71.9% in the TT-TP group and 75.0% in the CBT-TP group (P>0.05). These results indicate that CBT-PLIF resulted in the equivalent early fusion status to TT-PLIF and that compared with the same shape P cage, the TP cage did not improve early fusion status after both TT-PLIF and CBT-PLIF.

Risk factors for polyetheretherketone cage subsidence following minimally invasive transforaminal lumbar interbody fusion.

Interbody cage subsidence is a postoperative complication leading to poor outcomes after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). This study aimed to identify risk factors of cage subsidence in lumbar spinal diseases after MIS-TLIF using polyetheretherketone (PEEK) cage. In this retrospective cohort study, plain radiographs and three-dimensional computed tomography (3D-CT) performed 12months after MIS-TLIF were evaluated, and the risk of cage subsidence was calculated with odds ratio (OR), confidence interval (CI), and logistic regression analysis. A total of 114 patients (mean age, 65years) and 135 levels were included in this study: 80 (59.3%) with and 55 (40.7%) without cage subsidence. Multifidus atrophy showed the strongest association with PEEK cage subsidence (p < 0.001). Compared to those with normal mass, the odds of PEEK cage subsidence were 76.0 (95% CI: 3.9-1472.9) for severe atrophy. The factors significantly associated with cage subsistence were posterior cage position (OR = 4.2; p = 0.005), cage height ≥ 12mm (OR = 7.6; p = 0.008), use of an autograft mixed with demineralized bone matrix (DBM) (OR = 5.8; p = 0.002), body mass index (BMI) > 27.5kg/m2 (OR = 4.2; p = 0.03), and titanium-coated PEEK (Ti-PEEK) cage-type (OR = 38.4, p = 0.02). In MIS-TLIF with a PEEK cage, the factors associated with an increased risk of cage subsidence were higher BMI, increased severity of multifidus muscle atrophy, Ti-coated PEEK cage-type, cage height ≥ 12mm, use of DBM mixed autograft, and posterior cage position.

Single-Level Cervical Disc Replacement Using a PEEK-on-Ceramic Implant: Results of a Multicenter FDA IDE Trial With 24-Month Follow-up.

Many early cervical total disc replacements (TDRs) produced motion through a ball-and-socket action, with metal endplates articulating with a plastic core. Polyetheretherketone (PEEK) is used increasingly for spinal implants due to its mechanical properties and lack of artifacts on imaging. A TDR was designed with titanium-coated PEEK endplates and a ceramic core. The purpose of this study was to compare this TDR with anterior cervical discectomy and fusion (ACDF) to treat single-level cervical disc degeneration. This was a prospective, nonrandomized, historically controlled, multicenter US Food and Drug Administration (FDA) Investigational Device Exemption (IDE) trial. Patients received the PEEK-on-ceramic Simplify® Cervical Artificial Disc (n = 150). The historic control group included 117 propensity-matched ACDF patients from an earlier IDE trial. The primary outcome was a composite success classification at the 24-month follow-up. Outcome measures included the Neck Disability Index (NDI), neurological status, adverse events, subsequent surgery, a visual analog scale assessing neck and arm pain, and the Dysphagia Handicap Index. Radiographic assessment included flexion/extension range of motion and heterotopic ossification. Facet joints were assessed at 24 months using MRI. The success rate was significantly greater in the TDR group vs the ACDF group (93.0% vs 73.6%; P < .001). Mean NDI, neck pain, and arm pain scores improved significantly in both groups at all follow-up points. Mean NDI scores in the TDR group were significantly lower than ACDF scores at all follow-up points. There were no significant differences in the rates of serious adverse events. The range of motion of the TDR level had increased significantly by 3 months and remained so throughout follow-up. Facet joint assessment by MRI in the TDR group showed little change from preoperation. The TDR had an acceptable safety profile and a significantly greater composite success rate than ACDF. These results support that the PEEK-on-ceramic TDR is a viable alternative to ACDF for single-level symptomatic disc degeneration. This study found that the PEEK-on-ceramic TDR is a viable treatment for symptoms related to cervical disc degeneration and offers similar or superior outcomes compared with fusion. 2.

Comparison of Short-Term Radiographical and Clinical Outcomes After Posterior Lumbar Interbody Fusion With a 3D Porous Titanium Alloy Cage and a Titanium-Coated PEEK Cage.

Study Design:Clinical case series.Objectives:To compare the short-term (≤1 year) radiographical and clinical outcomes between posterior lumbar interbody fusion (PLIF) with a titanium-coated poly-ether-ether-ketone (TCP) cage and PLIF with a three-dimensional porous titanium alloy (PTA) cage.Methods:Overall, 63 patients who had undergone 1- or 2-level PLIF since March 2015 were enrolled (median age, 71 years). The first 34 patients underwent PLIF with TCP cages (until June 2017) and the next 29 patients with PTA cages. Fusion status, vertebral endplate cyst formation (cyst sign: grade 0, none; grade 1, focal; and grade 2, diffuse), cage subsidence (grade 0, <1 mm; grade 1, 1–3 mm; and grade 2, >3 mm), and patient-reported quality of life (QOL) outcomes based on the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were compared at 6 months and 1 year postoperatively between the 2 cage groups.Results:Cyst sign and cage subsidence grades were significantly lower in the PTA cage group than in the TCP cage group at 6 months postoperatively (cyst sign, p = 0.044; cage subsidence, p = 0.043). In contrast, the fusion rate and surgery effectiveness based on JOABPEQ at both 6 months and 1 year postoperatively were not different between the 2 groups.Conclusions:Patient-reported QOL outcomes were similar between the TCP and PTA cage groups until 1 year postoperatively. However, a higher incidence and severity of postoperative vertebral endplate cyst formation in patients with the TCP cage was a noteworthy radiographical finding.

PLIF surgery with titanium-coated PEEK or uncoated PEEK cages: a prospective randomised clinical and radiological study.

This study aimed to compare clinical results and fusion rates of uncoated polyetheretherketone (PEEK) cages with titanium-coated PEEK cages in posterior lumbar interbody fusion (PLIF) surgery. A prospective randomised study including 60 patients with one- or two-segment lumbar degenerative diseases. Patients received either titanium-coated PEEK cages (group A) or uncoated PEEK cages (group B). Fusion rates were evaluated on plain X-rays and CT scans after 6 and 12months. Clinical follow-up (visual analogue scale, VAS; Oswestry Disability Index score, ODI; EQ-5D) was performed for 24months. Fifty-five patients (92%) (36 female, 19 male) had a complete follow-up. There were no statistically significant differences in demographic, peri- or intraoperative data between groups A and B. ODI, VAS and EQ-5D improved significantly (p < 0.001) after surgery without statistically significant differences between the two groups. Overall, 65 operated segments could be evaluated for fusion (group A: 29 segments, group B: 36 segments, p = 0.6). Osseous integration of the cage surface improved significantly (p < 0.001) in both groups between 6 and 12months after surgery. At 12-month follow-up, neither radiolucency nor signs of instability or dislocation were noted. Fusion was present in CT scans as follows: (a) bone growth through cage pores (A: 100%, B: 100%); (b) bone growth outside the cages (A: 48%, B: 61%; p = 0.3). PEEK and titanium-coated PEEK cages for PLIF produce equally favourable clinical and radiological results up to 24months post-surgery. The fusion rate was not different.

Advantages and Disadvantages of the Use of Various Types of Interbody Implants in Cervical Spine Surgery. Critical Review of the Literature.

Most cervical spine procedures in patients with degenerative disc disease involve discectomy and remo-val of osteophytes in posterior vertebral body surfaces followed by interbody stabilisation with an interbody implant. Interbody implants are made of a variety of materials, differing in structural design, shape and surface topography. Considering that fusion between the implant and host bone is crucial for long-term positive outcomes, the choice of an appropriate implant is significantly important clinically and continues to be an important area of study. Relevant published studies indexed by Medline were identified via PubMed and reviewed. The findings were combined with the authors' experiences. The database query was based on keywords related to implants in cervical spine surgery. This article presents the currently most popular types of implants by describing their properties and indicating their strengths and weaknesses as well as differences between different implant types. Currently, the most popular interbody cages in cervical spine surgery are polyetheretherketone (PEEK) im-plants, titanium-coated PEEK implants and titanium implants. Besides the type of material used, the shape and surface structure of an implant appear to be of significant importance for a successful bony fusion. 1. 3D printing and the ability to produce 3-dimensional porous-surfaced implants opens up considerable pro-spects for this technique in the production of modern interbody implants. 2. Implants that facilitate the engagement (interlocking) of greater volumes of bone (e.g. porous implants) offer better implant fixation, with the type of material used being less important.

Follow-up of a new titanium-coated polyetheretherketone cage for the cervical spine

Poly-ether-ether-ketone (PEEK) cages have lower modulus of elasticity when compared with Titanium (TTN) cages. This suggests that PEEK-cages could show a lower rate of subsidence after anterior cervical discectomy-fusion (ACDF) and might lead to a lower loss of correction. We investigated the one to five year-results of standalone PEEK-TTN-porous coated cages in a patient cohort from 2014 to 2017. The patients underwent single-level ACDF for disc herniation and degenerative discopathy. Clinical and radiological outcome were assessed in 50 eligible patients after a mean of 27 months. Results: Solid arthrodesis was found in 84%. Neck disability index (NDI), and visual analogue scale (VAS) of neck and arm show comparable results to the literature. Conclusions: Clinical and radiological outcomes of ACDF with PEEK-body-cages with a porous coated surface show good bony integration. The modulus of elasticity, design, shape, size, cage surface architecture, as well as bone density, endplate preparation, radical microdiscectomy and distraction during surgery should be considered as important factors influencing the clinical results. One main advantage, over titanium cages, is the absence of MRI artifacts, allowing an excellent postoperative follow-up.

The Titanium-coated PEEK Cage Maintains Better Bone Fusion With the Endplate Than the PEEK Cage 6 Months After PLIF Surgery: A Multicenter, Prospective, Randomized Study.

A multicenter, randomized, open-label, parallel-group trial. To investigate interbody bone fusion rates in titanium-coated polyetheretherketone (TiPEEK) and polyetheretherketone (PEEK) cages after posterior lumbar interbody fusion (PLIF) surgery. Previous clinical studies have not revealed any significant difference in bone fusion rates between TiPEEK and PEEK cages. During one-level PLIF surgery, 149 patients (84 men, 65 women, mean age 67 yr) were randomly allocated to use either a TiPEEK cage (n = 69) or PEEK cage (n = 80). Blinded radiographic evaluations were performed using computed tomography and assessed by modified intention-to-treat analysis in 149 cases and per-protocol analysis in 143 cases who were followed for 12 months. Clinical outcomes were assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and the Oswestry Disability Index. The interbody union rate at 12 months after surgery was 45% owing to a very strict definition of bone fusion. The rates of bone fusion were significantly higher at 4 and 6 months after surgery in the TiPEEK group than in the PEEK group in the unadjusted modified intention-to-treat analysis and were significantly higher at 6 months in the unadjusted per-protocol analysis. Binary logistic regression analysis adjusted for sex, age, body mass index, bone mineral density, and surgical level showed that using a TiPEEK cage (odds ratio, 2.27; 95% confidence interval: 1.09-4.74; P = 0.03) was independently associated with bone fusion at 6 months after surgery. Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and Oswestry Disability Index results improved postoperatively in both groups. Using the TiPEEK cage for PLIF enabled the maintenance of better bone fusion to the endplate than using the PEEK cage at 6 months after the surgery. Our findings suggest the possibility of an earlier return to rigorous work or sports by the use of TiPEEK cage. 1.

Safety of anterior cervical discectomy and fusion using titanium-coated polyetheretherketone stand-alone cages: Multicenter prospective study of incidence of cage subsidence

This multicenter prospective study investigated cage subsidence in anterior cervical discectomy and fusion (ACDF) using titanium-coated polyetheretherketone (PEEK) stand-alone cages. This study recruited patients who underwent 1- or 2-level ACDF using titanium-coated PEEK stand-alone cages for cervical disc disease. Patients with acute trauma or past cervical spine operations were excluded. Sixty-two cages in 42 patients were eligible for analysis. Minimum follow-up was 6 months after ACDF. Significant cage subsidence was recognized in 11 of 62 cages (17.7%). Cage subsidence was predominantly moderate (14.5%), with severe subsidence found in only 2 cages (3.2%). The slowest occurrence of cage subsidence was 6 months after surgery, in 4 of 11 cages. Frequency of cage subsidence did not differ significantly between patients <65 and ≥65 years old. Patients with and without cage subsidence both demonstrated significant improvement of neurological function. Cage subsidence resulted in aggravation of local angle, but finally did not affect C2-7 angle or cervical tilt angle. Severe cage subsidence was found in only 3.2% of patients within 6 months after ACDF. Cage subsidence aggravated local angle, but finally did not affect C2-7 angle or cervical tilt angle. One- or 2-level ACDF using titanium-coated PEEK stand-alone cages appears safe and justified, even in elderly patients.

Enhanced bioactivity of titanium-coated polyetheretherketone implants created by a high-temperature 3D printing process

Polyetheretherketone (PEEK), one of the potential alternatives to metallic materials for implants, necessarily involves high temperature process conditions to be three-dimensionally (3D) printed. We developed a 3D printing setup equipped with thermally stabilized modules of the printing nozzle and building chamber, by which the PEEK implants could be successfully manufactured. Under optimized printing conditions, the maximal mechanical strength of the 3D printed sample attained over 80% of the original bulk property of PEEK. To enhance the interfacial biocompatibility, the as-printed implants were postprocessed with titanium (Ti) sputtering. The Ti-coated surfaces were evaluated through characterization studies of x-ray diffraction spectra, microscopic topographies, and wetting properties. For the in vitro tests, preosteoblasts were cultured on the developed PEEK-Ti structures and evaluated in terms of cell adhesion, proliferation, and osteogenic differentiation. In addition, the bone regeneration capability of the PEEK-Ti implants was confirmed by animal experiments using a rabbit tibia defect model for a period of 12 weeks. In the overall in vitro and in vivo tests, we confirmed the superior bioactivities of the Ti-modified and 3D printed interface by comparisons between the samples of machined and printed samples with or without Ti coating. Taken together, the comprehensive manufacturing approaches that involve 3D printing and biocompatible postprocessing are expected to have universal applicability in a wide range of bone tissue engineering.