Total Disc Replacement Research Articles

What is the True Cost of Motion Preservation? A Time-Driven Activity-Based Cost Analysis of Anterior Cervical Discectomy and Fusion versus Disc Replacement

Total disc replacement (TDR) has become a viable alternative to anterior cervical discectomy and fusion (ACDF) for select patients. Although most comparative studies have assessed outcomes, cost differences remain largely uninvestigated. This information is critical as we move towards value-based reimbursement. To address this knowledge gap, we used time-driven activity-based costing (TDABC) to compare total intraoperative costs between the two procedures. Total cost was divided into direct (personnel and supply cost) and indirect costs (administrative and overhead costs). Individual costs were determined through direct observation, electronic medical records, and through querying multiple departments (including business operations, sterile processing, plant operations, and pharmacy). Timestamps for all involved personnel and material resources were documented, in conjunction with process mapping of the intraoperative period. Total intraoperative costs were estimated for all ACDFs (n=810) and TDRs (n=54) from 2017 to 2022. Regression analyses were performed to identify factors associated with total cost. A total of 810 and 54 patients underwent one- and two-level ACDFs and TDRs, respectively. The average total intraoperative cost for an ACDF was $6,776 +/- $2,808, compared to $12,026 +/- $4,235 for TDR. Supply cost accounted for the majority of total cost for both procedures ($4,173 +/- $2,225 for ACDF and $9,532 +/- $4,010 for TDR). On multivariable linear regression analysis, TDR was associated with roughly $3,885 of additional cost compared to ACDF (p<0.001), as well as $4,072 in additional supply cost (p<0.001), most of which was driven by the higher cost of implants (p<0.001). TDABC is a highly useful methodology for estimating differences in true costs between procedures and determining cost drivers. TDRs were associated with an additional $3,885 of total intraoperative cost as compared to ACDFs, the majority of which was driven by the cost of implants.

Cervical Lordosis Correction and Segmental Height in Anterior Cervical Surgeries; The Role of Implant Choice

This study aims to compare the impact of 3 surgical techniques-stand-alone cage placement (SAC), anterior cervical plate (ACP) fixation, and total disc replacement (TDR)-on cervical lordosis restoration and segmental height after anterior cervical discectomy at C5-6 level. To eliminate the effect of lordosis between different levels, patients operated on at the same level were included in the study. Restoring cervical lordosis is crucial for improving patient outcomes, including pain reduction and preventing mechanical complications. A retrospective screening of 89 patients who underwent single-level C5-6 surgery between 2011 and 2021 was analyzed. Patients were categorized into 3 groups based on the surgical technique used: SAC, ACP, or TDR. Lordotic angles and segmental heights were measured preoperatively, first-month follow-up, and at the 24-month follow-up. Statistical analysis was conducted using the Wilcoxon Signed Rank test and ANOVA, with a significance threshold set at P < 0.05. All 3 techniques resulted in significant early and late postoperative increases in both global and segmental lordosis. The early postoperative height gain was most pronounced in the ACP group. However, no significant differences in lordosis or height preservation were observed among the groups at the 24-month follow-up. These findings align with previous studies, indicating comparable long-term outcomes across these surgical approaches. SAC placement, ACP fixation, and TDR, all effectively restore cervical lordosis and segmental height after anterior cervical discectomy at the C5-6 level. Despite early differences, the long-term results were similar, suggesting that the choice of technique should be based on individual patient needs and specific surgical considerations.

A comparative study of the effect of facet tropism on the index-level kinematics and biomechanics after artificial cervical disc replacement (ACDR) with Prestige LP, Prodisc-C vivo, and Mobi-C: a finite element study

IntroductionArtificial cervical disc replacement (ACDR) is a widely accepted surgical procedure in the treatment of cervical radiculopathy and myelopathy. However, some research suggests that ACDR may redistribute more load onto the facet joints, potentially leading to postoperative axial pain in certain patients. Earlier studies have indicated that facet tropism is prevalent in the lower cervical spine and can significantly increase facet joint pressure. The present study aims to investigate the changes in the biomechanical environment of the cervical spine after ACDR using different prosthese when facet tropism is present.MethodsA C2-C7 cervical spine finite element model was created. Symmetrical, moderate asymmetrical (7 degrees tropism), and severe asymmetrical (14 degrees tropism) models were created at the C5/C6 level by adjusting the left-side facet. C5/C6 ACDR with Prestige LP, Prodisc-C vivo, and Mobi-C were simulated in all models. A 75 N follower load and 1 N⋅m moment was applied to initiate flexion, extension, lateral bending, and axial rotation, and the range of motions (ROMs), facet contact forces(FCFs), and facet capsule stress were recorded.ResultsIn the presence of facet tropism, all ACDR models exhibited significantly higher FCFs and facet capsule stress compared to the intact model. In the asymmetric model, FCFs on the right side were significantly increased in neutral position, extension, left bending and right rotation, and on both sides in right bending and left rotation compared to the symmetric model. All ACDR model in the presence of facet tropism, exhibited significantly higher facet capsule stresses at all positions compared to the symmetric model. The stress distribution on the facet surface and the capsule ligament in the asymmetrical models was different from that in the symmetrical model.ConclusionsThe existence of facet tropism could considerably increase FCFs and facet capsule stress after ACDR with Prestige-LP, Prodisc-C Vivo, and Mobi-C. None of the three different designs of implants were able to effectively protect the facet joints in the presence of facet tropism. Research into designing new implants may be needed to improve this situation. Clinical trials are needed to validate the impact of facet tropism.

Fiber‐Dependent 3D Anisotropic Stiffness‐Tunable Biomimetic Intervertebral Disc via Multi‐Material Additive Manufacturing

AbstractLumbar intervertebral disc degeneration is a global musculoskeletal disorder. Total disc replacement is an effective treatment for symptomatic degeneration unresponsive to conservative care. However, current artificial discs, with their joint‐like structural design and homogeneous materials, fail to replicate the 3D anisotropic stiffness of natural discs. Inspired by the intricate structure and material gradient of the natural disc, a biomimetic intervertebral disc is designed and fabricated using multi‐material additive manufacturing. The biomimetic disc exhibits 3D anisotropic stiffness similar to natural discs. By adjusting the hardness, diameter, and arrangement of fibers in annulus fibrosus, the biomimetic disc closely matches the 3D anisotropic stiffness of the natural lumbar disc, exceeding 90% similarity and outperforming existing artificial discs. This highlights the crucial role of fiber properties in disc stiffness regulation and enhances the understanding of biomechanical functions of structures and materials in the annulus fibrosus of human discs. These insights may inspire high‐performance artificial disc designs.

Combined effect of artificial cervical disc replacement and facet tropism on the index-level facet joints: a finite element study

BackgroundArtificial Cervical Disc Replacement (ACDR) is an effective treatment for cervical degenerative disc diseases. However, clinical information regarding the facet joint alterations after ACDR was limited. Facet tropism is common in the sub-axial cervical spine. Our previous research indicated that facet tropism could lead to increased pressure on the cervical facet joints. This study aimed to assess the impact of facet tropism on the facet contact force and facet capsule stress after ACDR.MethodsA C2–T1 cervical finite element model was constructed from computed tomography (CT) scans of a 28-year-old male volunteer. Symmetrical, moderate asymmetrical (7 degrees tropism), and severe asymmetrical (14 degrees tropism) models were created at the C5/C6 level by altering the facet orientation at the C5-C6 level. The C5/C6 ACDR was simulated in the intact, moderate asymmetrical and severe asymmetrical models. A 75-N follower load with 1.0-Nm moments was applied to the top of C2 vertebra in the models to simulate flexion, extension, lateral bending, and axial rotation with the T1 vertebra fixed. The range of motions (ROMs) under all moments, facet contact forces (FCFs) and facet capsule strains were tested.ResultsIn the asymmetrical model, the right FCFs considerably increased under flexion, extension, right bending, left rotation, especially under right bending the right sided FCF of the severe asymmetrical model was about 5.44 times of the neutral position, and 3.14 times of the symmetrical model. and concentrated on the cephalad part of the facets. The facet capsule stresses on both sides remarkably increased under extension, lateral bending and right rotation. In the moderate and severe asymmetrical models, the capsule strain was greater on both sides of each position than in the symmetric model.ConclusionsThe face tropism increased facet contact force and facet capsule strain after ACDR, especially under extension, lateral bending, and rotation, and also could result in abnormal stress distribution on the facet joint surface and facet joint capsule. The results suggest that face tropism might be a risk factor for post-operative facet joint degeneration progression after ACDR. Facet tropism may be noteworthy when ACDR is considered as a surgical option.

Impact of Age on the Occurrence of Vascular Complications in Patients Undergoing Anterior Lumbar Approach Surgery.

Retrospective cohort study. To investigate the impact of age on the incidence of vascular complications in patients undergoing anterior lumbar approach surgery. Anterior approach lumbar spinal surgery may facilitate the use of intervertebral devices with larger endplate coverage and increased lordosis. Despite the advantages of this approach, risks related to vascular injury in older patients have been described in the literature. In total, 751 consecutive patients with degenerative spinal pathology who underwent stand-alone anterior lumbar interbody fusion (ALIF), ALIF combined with posterior fusion and/or instrumentation (360), total disc replacement, or hybrid procedures (ALIF and total disc replacement) were included. Data collected included general patient descriptive data, surgery details, intraoperative vascular injury, and postoperative vascular complications (deep vein thrombosis and/or pulmonary embolism). Rates of vascular complications were compared across age groups. In addition, the mean age of patients was compared between those with versus without vascular complications. Overall mean age was 50.4 years (range: 20-83 yr). The mean estimated blood loss was 91.3mL (range: 10-2800mL). A total of 15 patients, 2.0%, had vascular complications. There were 10 cases (1.3%) of intraoperative injury to iliac arteries or iliolumbar veins (mean blood loss was 721mL, and all were repaired intraoperatively). Postoperatively, 6 patients (0.8%) developed deep vein thrombosis and/or pulmonary embolism (one patient had both). With respect to age, there were no significant differences in rates of intraoperative, postoperative, or combined vascular complication rates across the age group ( P > 0.38). In addition, there were no statistically significant differences in the mean ages of patients with versus those without vascular complications ( P > 0.17). Overall incidence of vascular complications was 2.0%. No relationship between vascular complications and age was demonstrated. These data suggest that increased age may not necessarily be an absolute contraindication for anterior lumbar approach surgery. Level III.

Analysis of factors influencing the development of paravertebral ossification in the distant future after artificial disc replacement for cervical disc herniation

Analysis of factors influencing the development of paravertebral ossification in the distant future after artificial disc replacement for cervical disc herniation

Three dimensional-printed artificial disc replacement for single-level cervical spondylosis: a cohort study.

To compare the clinical efficacy of 3D-printed artificial discs with that of ACDF for treating cervical spondylosis. This was a retrospective analysis of 73 patients with single-level cervical spondylosis who met the inclusion criteria between January 2020 and December 2022 at XX Hospital. The patients were divided: 38 patients in the ACDF group and 35 patients in the CADR group. Patient general information, including operation time and intraoperative blood loss, was collected. The clinical effect of the combination therapy was evaluated by the VAS, JOA, and NDI. The radiological effect was evaluated using the ROM test. Ethics No. 201,606,009. The average follow-up times in the ACDF and CADR groups were 28.24 ± 4.65 and 29.11 ± 5.06 months, respectively (P = 0.443). Clinical symptoms (evaluated by VAS, NDI, and JOA) are significantly improved in both the ACDF and CADR groups with similar efficacy. The preoperative ROM of the ACDF group was 40.03 ± 8.79, while that of the CADR group was 42.11 ± 7.98 (P = 0.293). However, the postoperative ROM in the ACDF group was 35.29 ± 7.23, which was lower than that in the CADR group (40.43 ± 6.98) (P = 0.003). Furthermore, only one patient in the ACDF group experienced mild dysphagia after surgery, and the patient recovered within three days. ASD occurred in nine patients in the ACDF group and in two patients in the CADR group (Χ²=4.597, P = 0.032). Compared with ACDF, 3D-printed artificial discs for treating single-level cervical spondylosis have proven to be clinically effective; it associated with less blood loss and a lower incidence of ASD, and maintain a better cervical ROM.

Changes in the Centers of Rotation in Different Prosthetic Segments Following Continuous Two-Level Cervical Disc Replacement: A Retrospective Study

To observe the short-term to medium-term therapeutic effects and radiological outcomes of adjacent 2-level cervical spondylosis treated with artificial cervical disc replacement (ACDR) using Mobi-C and Bryan discs. To observe changes and discrepancies in the flexion-extension centers of rotation (FE-COR) of different ACDR segments. Twenty-four patients undergoing 2-level (C4/5 and C5/6) ACDR were analyzed retrospectively (11 patients in the Mobi-C group and 13 patients in the Bryan group). Clinical outcomes were assessed using modified Japanese Orthopedic Association score, Neck Disability Index, and visual analog scale. Preoperative and 2years' follow-up radiographs were collected to compare total cervical spine curvature (C2-C7) range of motion (ROM), upper and lower ACDR segmental ROM, and the operated adjacent segmental ROM. The FE-COR of the ACDR segment was measured using the mid-plumb line method. The degree of disc degeneration in the adjacent segment was observed. At the 2years' follow-up, in both group, the modified Japanese Orthopedic Association score increased significantly, and the Neck Disability Index and neck and upper extremity visual analog scale scores decreased significantly compared with preoperative (P<0.05). There were no significant statistical differences in postoperative scores between the 2 groups (P > 0.05). The overall cervical ROM, the upper and lower segmental ROM at the 2years' follow-up showed no significant statistical differences compared with the preoperative period (P > 0.05). There was no statistically significant difference in the adjacent segmental ROMs compared with the preoperative period (P > 0.05). Furthermore, the statistical analysis revealed no significant differences in the measurements of the ROM at each time points between the Mobi-C Group and the Bryan Group (P > 0.05). There was no significant difference in the preoperative FE-COR-X (indicating the horizontal position of the point in the coordinate system) and FE-COR-Y (indicating the vertical position of the point in the coordinate system) of upper or lower ACDR segments between the 2 groups (P > 0.05). At the 2years' follow-up, there were significant differences both in FE-COR-X and FE-COR-Y between the 2 groups (P < 0.05). For the Mobi-C group, in both the upper and lower segment, the FE-COR-X significantly increased compared with preoperative (P < 0.05), while the FE-COR-Y decreased compared with preoperative (P < 0.05). For the Bryan group, no significant changes were observed in the upper or lower segment in both FE-COR-X and FE-COR-Y compared with preoperative (P > 0.05). Fourty-eight adjacent segments (24 superior and 24 inferior segments) were included in the studies of adjacent segment disease. Four segments showed imaging adjacent segment disease (4/48, 8.33%) in 4 patients, of which 2 were mild and 2 were moderate according to the grading criteria. Among them, 2 were from the Mobi-C group and 2 were from the Bryan group. No severe imaging degeneration was observed. In continuous 2-level cervical ACDR surgery, both Mobi-C and Bryan artificial cervical discs achieved satisfactory clinical outcomes in the short to medium term postoperatively. The FE-COR exhibited different trends of change. In the Mobi-C group, the FE-COR for both upper and lower segments shifted anteriorly and inferiorly, whereas in the Bryan group, whether upper or lower, the FE-COR remained closer to the preoperative state. The changes in FE-COR did not significantly affect the short-term to medium-term clinical outcomes postoperatively.

Five-year Follow-up of a Prospective Food and Drug Administration Investigational Device Exemption Trial Evaluating a PEEK-on-Ceramic Cervical Disc Replacement.

Prospective trial comparing the investigation group to propensity matched historic control group. To evaluate 5-year results of single-level PEEK-on-ceramic cervical total disc replacement (TDR) compared to a propensity matched anterior cervical discectomy and fusion (ACDF) control group. Cervical TDR has gained acceptance as treatment for symptomatic disc degeneration. The design and materials used in these devices continue to evolve. Data were collected in the Food and Drug Administration Investigational Device Exemption trial for the PEEK-on-ceramic Simplify(®) Cervical Artificial Disc (n=150) with comparison to a propensity matched ACDF control group (n=117). All patients were treated for single-level cervical disc degeneration with radiculopathy and/or myelopathy. Clinical outcome was based on composite clinical success (CCS), Neck Disability Index (NDI), visual analog scales (VAS) assessing pain, re-operations, and satisfaction. Radiographic measures included segmental range of motion (ROM), disc space height, and heterotopic ossification (HO). Evaluations were performed pre-operatively and post-operatively within 2 and 6 weeks, and 3, 6, 12 months, and annually thereafter. At 5-year follow-up, CCS was significantly greater with TDR than ACDF (91.1% vs. 74.6%; P<0.01). In the TDR group, the mean NDI score was 63.3 pre-operatively, reduced significantly to 23.1 at 6 weeks and remained below 20 throughout 5-year follow-up. In the ACDF group, the mean pre-operative NDI score was 62.4, decreasing to 33.7 at 6 weeks, and ranged from 25.9 to 21.5 throughout follow-up. Mean NDI scores were significantly lower in TDR group at all post-operative points (P<0.05). Mean TDR ROM was 7.3o pre-operatively and 10.1o at 5 years. Bridging HO occurred in 9%. With TDR, there were 6 re-operations (4.0%) vs. 11 (9.4%) with ACDF (P>0.40). PEEK-on-ceramic TDR produced significantly improved outcomes maintained throughout 5-year follow-up, were similar or superior to ACDF, supporting TDR in appropriately selected patients.

C5 Palsy after Cervical Disc Arthroplasty: Two Case Reports and Literature Review

Cervical disc arthroplasty (CDA), also known as cervical artificial disc replacement, has become an alternative for the treatment of cervical spondylosis with radicular or myelopathic symptoms. However, there is limited literature regarding its complications and outcomes. We present two cases that developed C5 nerve palsy (C5P) following two-level CDA. Both patients presented with C5P in a delayed fashion with 2/5 and 1/5 deltoid weakness on MMT, respectively. Postoperative imaging did not demonstrate any spinal cord compression and symptoms resolved (5/5 on MMT) with conservative management in both cases. To our knowledge, these represent the first cases of delayed C5P after cervical arthroplasty reported in the literature. We performed a literature review to further enhance our knowledge regarding CDA. By understanding its pathophysiology and response to treatment, these cases can serve as a guide for spine surgeons and improve their future outcomes.

P106. Disc to Disc: early results of the multicenter, prospective, randomized clinical investigational device exemption trial comparing a novel total disc replacement (TDR) to an approved TDR control at two contiguous levels of the cervical spine

P106. Disc to Disc: early results of the multicenter, prospective, randomized clinical investigational device exemption trial comparing a novel total disc replacement (TDR) to an approved TDR control at two contiguous levels of the cervical spine

P213. Strategies for addressing a series of failed cervical total disc replacements

P213. Strategies for addressing a series of failed cervical total disc replacements

P103. Seven-year outcomes for single-level total disc replacement with a novel viscoelastic artificial cervical disc

P103. Seven-year outcomes for single-level total disc replacement with a novel viscoelastic artificial cervical disc

P105. Clinical analysis of 108 patients with lumbar total disc replacement after prior fusion

P105. Clinical analysis of 108 patients with lumbar total disc replacement after prior fusion

Treatment of failed cervical total disc replacements in a series of 53 cases and description of a management strategy.

To describe modes of failure of cervical TDR, their related treatment strategies, and to describe a management strategy for the treatment of failed cervical TDR. This retrospective study was based on a consecutive series of 53 cervical TDR patients who underwent removal or revision surgery. Chart review was conducted to collect general descriptive data, reasons for TDR removal/revision, duration from index implantation to re-operation, and the subsequent procedure performed. Among 53 patients, 36 underwent TDR removal and fusion, 16 underwent TDR removal and replacement with another TDR, and one patient's TDR was revised by repositioning. The mean duration from index surgery to removal/revision was 40.1months (range: 3days-222months). In all cases, removal/revision surgery was completed without complication. The most common reason for removal was severe osteolysis, often involving C. acnes infection, and was primarily associated with one implant type. TDR removal and fusion were performed for subsidence, device migration, treatment of symptoms arising from posterior anatomy (facet joints, etc.), approach-related complications and pain. TDR replacement was feasible for hypermobility, metal allergy, implant locked in kyphosis, and oversized implant use. In one case of TDR malpositioning, the device was successfully revised into appropriate position. After cervical TDR failure, replacing a TDR with another implant can be feasible. Reasons for revision or removal after cervical TDR surgery include biomechanical failure, implant migration, surgeon or technical error, or biological reasons. The type of failure can help the surgeon create a strategy to address these complications.

Expert consensus on clinical application of cervical artificial disc replacement

Cervical artificial disc replacement preserves the range of motion after the decompression, and this technology has achieved good clinical results. The indications, surgical procedures, and perioperative management of cervical disc arthroplasty are different from traditional anterior cervical decompression and fusion. The Health Management and Enhanced Recovery of Cervical Spine Disorders Committee, Chinese Research Hospital Association has established an expert group to draw up this expert consensus through literature analysis and professional discussions. The purpose of this consensus is to standardize the surgical indications and patient selection of cervical artificial disc replacement, to guide surgical procedures and perioperative management, and to improve the clinical outcomes of cervical artificial disc replacement.

The Scientific Evidence for Lumbar Total Disk Replacement Surgery

Abstract Lumbar total disk replacement (TDR) has been in use since the 1980s, yet its adoption has not paralleled that of hip or knee arthroplasty or cervical TDR, which was introduced years after lumbar arthroplasty. If the lack of adoption is related to concerns about the safety and/or effectiveness of these implants, these issues have been extensively addressed in the literature. This narrative review aims to concisely report on the evidence published in the peer-reviewed literature related to lumbar TDR. Literature was identified from online databases such as PubMed, Scopus, and ScienceDirect, supplemented by the authors’ institution’s comprehensive database of TDR articles. By the end of 2023, there were at least 816 articles published on lumbar TDR covering all aspects of this technology, including biomechanics, clinical outcome, radiographic outcome, safety as assessed by re-operations and complications, and the cost related to this treatment intervention. Consistently, the evidence indicates that TDR yields outcomes similar or superior to fusion for treating painful disk degeneration unresponsive to non-operative care in appropriately selected patients.

Exosome-mediated Repair of Intervertebral Disc Degeneration: The Potential Role of miRNAs.

Intervertebral disc degeneration (IVDD) is a serious condition that manifests as low back pain, intervertebral disc protrusion, and spinal canal stenosis. At present, the main treatment methods for IVDD are surgical interventions such as discectomy, total disc replacement, and spinal fusion. However, these interventions have shown limitations, such as recurrent lumbar disc herniation after discectomy, lesions in adjacent segments, and failure of fixation. To overcome these shortcomings, researchers have been exploring stem cell transplantation therapy, such as mesenchymal stem cell (MSC) transplantation, but the treatment results are still controversial. Therefore, researchers are in search of new methods that are more efficient and have better outcomes. The exosomes from stem cells contain a variety of bioactive molecules that mediate cell interactions, and these components have been investigated for their potential therapeutic role in the repair of various tissue injuries. Recent studies have shown that MSC-derived miRNAs in exosomes and vesicles have therapeutic effects on nucleus pulposus cells, annulus fibrosus, and cartilage endplate. miRNAs play a role in many cell activities, such as cell proliferation, apoptosis, and cytokine release, by acting on mRNA translation, and they may have immense therapeutic potential, especially when combined with stem cell therapy. This article reviews the current status of research on intervertebral disc repair, especially with regard to the latest research findings on the molecular biological mechanisms of miRNAs in MSC-derived exosomes in intervertebral disc repair.

Lumbar Total Disc Replacement Leads to Increased Subsequent Facet Injections Compared to Anterolateral Lumbar Interbody Fusions

Study Design Retrospective Matched Cohort. Objective Despite known consequences to the facet joints following lumbar total disc replacement (TDR), there is limited data on facet injection usage for persistent postoperative pain. This study uses real-world data to compare the usage of therapeutic lumbar facet injections as a measure of symptomatic facet arthrosis following single-level, stand-alone TDR vs anterolateral lumbar interbody fusion (ALIF/LLIF). Methods The PearlDiver database was queried for patients (2010-2021) with lumbar degenerative disc disease who received either a single-level, stand-alone TDR or ALIF/LLIF. All patients were followed for ≥2 years and excluded if they had a history of facet injections or spinal trauma, fracture, infection, or neoplasm. The two cohorts were matched 1:1 based on age, sex, insurance, year of operation, and medical comorbidities. The primary outcome was the use of therapeutic lumbar facet injections at 1-, 2-, and 5-year follow-up. Secondary outcomes included subsequent lumbar surgeries and surgical complications. Results After 1:1 matching, each cohort had 1203 patients. Lumbar facet injections occurred significantly more frequently in the TDR group at 1-year (6.07% vs 1.66%, P &lt; .0001), 2-year (8.40% vs 3.74%%, P &lt; .0001), and 5-year (11.47% vs 6.40%, P &lt; .0001) follow-up. 5-year injection-free probability curves demonstrated an 87.1% injection-free rate for TDR vs 92.9% for ALIF/LLIF. There was no clinical difference in the incidence of subsequent lumbar surgeries or complications. Conclusion Compared with ALIF/LLIF, patients who underwent TDR received significantly more facet injections, suggesting a greater progression of symptomatic facet arthrosis. TDR was not protective against reoperations compared to ALIF/LLIF.