Abstract Background Chronic low-back pain is a leading cause of global disability, with degenerative disc disease (DDD) recognized as a common structural contributor. While conservative therapies may provide temporary symptom relief, they do not address the underlying degeneration of the intervertebral disc. Surgical interventions, such as spinal fusion or total disc replacement, are invasive procedures that permanently alter the anatomical structure of the vertebral motion segment. Minimally invasive intradiscal therapies have the potential to bridge the treatment gap between non-surgical management and surgery. Intradiscal delivery of nucleus pulposus (NP) allograft is intended to structurally supplement the degenerating disc and restore native disc function. Preliminary studies have suggested that a single intradiscal administration of NP allograft (VIA Disc NP) may improve pain and function in patients with lumbar discogenic pain. Methods This is a randomized, double-blind, sham-controlled, multi-center clinical trial designed to evaluate the safety and efficacy of VIA Disc NP. Eligible participants are 22 to 85 years of age with MRI-confirmed lumbar DDD (modified Pfirrmann grade 3–7), axial low-back pain of at least 6 months’ duration, and functional impairment unresponsive to conservative treatment. Participants are randomized in a 2:1 ratio to receive either a single injection of VIA Disc NP or a sham procedure. The primary efficacy endpoint of this superiority trial is the proportion of participants achieving a ≥ 30% reduction in back pain severity at 12 months. Secondary endpoints include functional improvement (ODI), quality-of-life measures (EQ-5D-5L, PGIC), and opioid reduction. Sham participants who remain symptomatic at 12 months may cross over to receive active treatment. Discussion This trial will provide level-1 evidence of the safety and efficacy of supplemental NP allograft therapy in patients with moderate to severe lumbar discogenic pain. If successful, this approach may offer a minimally invasive, durable, and structure-preserving treatment alternative to spinal fusion or disc arthroplasty in a population with limited therapeutic options. Trial registration This trial is prospectively registered at ClinicalTrials.gov (Identifier: NCT06778447). Registered on January 16, 2025

Morgan P Lorio,1 Jon E Block2 1Orlando College of Osteopathic Medicine, Winter Garden, FL, USA; 2Private Practice, San Francisco, CA, USACorrespondence: Jon E Block, Private Practice, 2210 Jackson Street, Ste. 401, San Francisco, CA, 94115, USA, Tel +1 415 775 7947, Email jb@drjonblock.com

Study design: Prospective randomized controlled trial. Objective: This trial was designed to understand safety and effectiveness outcomes in subjects with three-level cervical degenerative disc disease treated with anterior cervical discectomy and fusion (ACDF) alone or supplemented with a posterior cervical fusion (PCF) performed using an investigational posterior cervical stabilization system (PCSS). Background: ACDF remains the most common surgical treatment for cervical disc disease. Long-segment (3+ disc levels) procedures are associated with increased risk of complications including symptomatic nonunion. Supplementing ACDF with PCF to form a circumferential cervical fusion (CCF) improves biomechanical stability but increases the surgical burden for the patient. Materials and methods: This multicenter study compared outcomes in participants with three-level symptomatic cervical disc degeneration treated with either ACDF or CCF. The CCF procedure incorporated PCF with PCSS. The primary endpoint was 12-month fusion success, defined by bridging bone across the interbody and range of motion <2 degrees across all treated disc levels. The 24-month secondary endpoint was a composite of fusion success, neck disability index (NDI) improvement, neurological status success, and freedom from surgical revision. Results: This protocol-defined interim analysis included 202 participants with 12-month outcomes and 116 participants with 24-month outcomes. Twelve-month fusion success was higher for CCF (61/100, 61%) compared with ACDF (17/102, 17%) ( P <0.001). The 24-month secondary endpoint was also improved with CCF compared with ACDF [51% (30/59) vs. 23% (13/57); P =0.002]. Revision rates were lower for CCF (1/59, 2%) compared with ACDF (13/57, 23%) ( P <0.001), with 11 of 13 ACDF revisions addressing symptomatic nonunion. Adding supplemental PCF with PCSS did not increase the rates of adverse events (ACDF=65%, CCF=46%, P =0.005). Conclusions: This study represents the first randomized controlled trial assessing treatment of three-level cervical disc disease. Long-segment ACDF demonstrated low fusion rates and high rates of revision. Adding supplemental PCF with PCSS improved fusion without increasing the risk of surgical complications.

Background:There is renewed interest in the intervertebral disc as a target for treatments aimed at ameliorating lumbar discogenic pain by restoring and preserving the natural structure and function of this component of the vertebral motion segment. Methods:Using a modified Delphi methodology involving a panel of 11 experts, we developed a simple, understandable clinical algorithm to serve as a foundation for objective decision making regarding the diagnosis and treatment of lumbar discogenic pain throughout the entire continuum of care. A decision tree approach was utilized with "either/or" choices at each branch or node in the algorithm. Clinical activities in this algorithm were divided into examination procedures and corresponding treatment interventions. Corresponding treatment options were designated based on published degenerative disc disease (DDD)-specific clinical practice guidelines and/or meta-analyses. Results:This algorithm recommends a systematic rule set for discogenic pain diagnostic and treatment options. Initially, the presence of lumbar discogenic pain is confirmed via assessment of a series of clinical signs including axial midline back pain (≥ 4 of 10), pain with flexion, sitting intolerance, positive pain provocation with sustained hip flexion, and absence of motor/sensory/reflex changes. Radiographic severity of DDD is graded by modified Pfirrmann grade (1 to 8). Treatment options are stratified by DDD severity to include conservative management (grades 1 and 2), minimally-invasive intradiscal therapies (grades 3 to 7), and more invasive surgical procedures (grade 8). Recognizing that the management program for patients with lumbar discogenic pain can be highly personalized, the treatment options recommended by this algorithm should be considered general guidance. Conclusion:The proposed algorithm offers an easy-to-use clinical tool for identifying, evaluating and treating patients with lumbar discogenic pain. The successful implementation of this algorithm involves an important interplay between advanced practice providers, interventional pain physicians and spine surgeons.

This historical vignette is a tribute to Professors Frederick P. Dewar and Edward H. Simmons who were pioneers in the evolution of posterior cervical fusion. In response to failures of other wiring techniques, they developed a posterior cervical fusion construct based on sound biomechanical principles. The so-called “Dewar” technique utilized contoured double cortico-cancellous iliac grafts as internal graft-splints fixed to the spine with threaded pins and wire to enhance posterior cervical stability. This technique has since been replaced by lateral mass screw constructs and interfacet fusion techniques which facilitate midline decompression while maintaining stability. This paper provides an historical perspective on the Dewar technique, illustrating its impact with previously unpublished findings from a radiographic case series of patients treated with the Dewar procedure and a comparative group of patients treated with interspinous wiring or triple wiring fusion technique. The Dewar procedure served as an important evolutionary step toward our contemporary approach to fusion of the posterior column that minimizes tissue disruption and maximizes interfacet stabilization.

Prospective randomized controlled trial. This trial was designed to understand safety and effectiveness outcomes in subjects with three-level cervical degenerative disc disease treated with anterior cervical discectomy and fusion (ACDF) alone or supplemented with a posterior cervical fusion (PCF) performed using an investigational posterior cervical stabilization system (PCSS). ACDF remains the most common surgical treatment for cervical disc disease. Long-segment (3+ disc levels) procedures are associated with increased risk of complications including symptomatic nonunion. Supplementing ACDF with PCF to form a circumferential cervical fusion (CCF) improves biomechanical stability but increases the surgical burden for the patient. This multicenter study compared outcomes in participants with three-level symptomatic cervical disc degeneration treated with either ACDF or CCF. The CCF procedure incorporated PCF with PCSS. The primary endpoint was 12-month fusion success, defined by bridging bone across the interbody and range of motion <2° across all treated disc levels. The 24-month secondary endpoint was a composite of fusion success, neck disability index (NDI) improvement, neurological status success, and freedom from surgical revision. This protocol-defined interim analysis included 202 participants with 12-month outcomes and 116 participants with 24-month outcomes. Twelve-month fusion success was higher for CCF (61/100, 61%) compared with ACDF (17/102, 17%) (P<0.001). The 24-month secondary endpoint was also improved with CCF compared with ACDF [51% (30/59) vs. 23% (13/57); P=0.002]. Revision rates were lower for CCF (1/59, 2%) compared with ACDF (13/57, 23%) (P<0.001), with 11 of 13 ACDF revisions addressing symptomatic nonunion. Adding supplemental PCF with PCSS did not increase the rates of adverse events (ACDF=65%, CCF=46%, P=0.005). This study represents the first randomized controlled trial assessing treatment of three-level cervical disc disease. Long-segment ACDF demonstrated low fusion rates and high rates of revision. Adding supplemental PCF with PCSS improved fusion without increasing the risk of surgical complications.

Background Sacroiliac joint (SIJ) dysfunction is a common cause of low back pain and associated gait disturbances that result from aberrant muscle activity and symmetry. This study evaluated the magnitude of improvement in gait characteristics in patients with chronic SIJ pain followed for six months after minimally invasive posterior SIJ fusion. Methods This was a single-arm, prospective, pilot study at two private practice orthopedic pain clinics. Gait characteristics were quantitated using a wireless wearable sensor. Ten patients (mean age: 63 ± 12 years) with abnormal SIJ-associated gait impairment were enrolled and underwent posterior SIJ fusion. Results Average gait velocity improved significantly from 69 ± 28.5 cm/sec at baseline to 99.9 ± 31.5 cm/sec at six months, reflecting an overall average improvement of 30.93 cm/sec or 55.4% (p=0.003). Gait speed, variability, and symmetry impairment parameters also improved with corresponding mean percentage improvements at six months of 27.8% (p=0.02), 19.7% (p=0.17), and 11% (p=0.27). A significant decrease in fall risk and increased timed-up-and-go assessments were noted, with improvements of 32.3% and 24.7%, respectively (p=0.004 for both comparisons). Conclusion These pilot findings demonstrate the first objective assessment of gait characteristics in patients with SIJ dysfunction undergoing minimally invasive posterior SIJ fusion.

INTRODUCTION:The objective of this article is to assess the potential of imaging, robotics, and artificial intelligence (AI) to significantly improve spine care, preoperative planning and surgery. AREAS COVERED:This article describes the development of lumbar total joint replacement (TJR) of the spine (MOTUS, 3Spine, Chattanooga, TN, U.S.A.). We discuss the evolution of intra-operative imaging, robotics, and AI and how these trends can intersect with lumbar TJR to optimize the safety, efficiency, and accessibility of the procedure. EXPERT OPINION:By preserving natural spinal motion, TJR represents a significant leap forward in the treatment of degenerative spinal conditions by providing an alternative to fusion. This transformation has already occurred and is continuing to evolve in the primary synovial joints such as hip, knee, shoulder and ankle where arthroplasty outcomes are now so superior that fusion is considered a salvage procedure. The convergence of imaging, robotics and AI is poised to reshape spine care by enhancing precision and safety, personalizing treatment pathways, lowering production costs, and accelerating adoption. However, the key challenges include ensuring continued collaboration between surgeons, researchers, manufacturers, and regulatory bodies to optimize the potential of TJR.

The implantation of the first motion-preserving artificial disc, the Charité, in the United States in 2000 sparked an enormous amount of enthusiasm among spine surgeons seeking an alternative to lumbar arthrodesis. In fact, the fervor for this new technology was so great that it precipitated the

BACKGROUND:Lumbar fusion eliminates motion at the operative level and is associated with altered load transfer and adjacent segment degeneration. Total joint replacement (TJR) of the lumbar spine is a motion segment reconstruction procedure performed via a bilateral transforaminal approach that allows direct neural decompression and replacement of both disc and facet function. This prospective investigational device exemption clinical trial compared TJR with a concurrent, propensity-score-weighted real-world evidence cohort treated with either instrumented transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody spine fusion (PLIF). METHODS:This multicenter investigational device exemption trial was conducted at 20 US sites. Patient-reported outcomes from 152 TJR subjects implanted with the MOTUS device were compared with 142 propensity score-weighted TLIF/PLIF controls. Lumbar-related disability was measured with the Oswestry Disability Index (ODI) and back and worst leg pain severity by a 100-mm visual analog scale (VAS). Minimal clinically important difference thresholds were ODI ≥ 15 points and VAS ≥ 20 mm; responder analyses were also conducted using ≥30% and substantial clinical benefit (≥50%) thresholds. Effect sizes were calculated using Cohen's d or h. RESULTS:Baseline characteristics were well balanced, and there were no statistically significant differences between study groups. At 12 months, mean ODI decreased by 45 points (71%) with TJR and 37 points (59%) with TLIF/PLIF. The adjusted between-group difference was 8.1 points (95% CI, 2.5-13.7; P = 0.005; Cohen's d = 0.39, small). VAS back and leg pain decreases were similar between groups, with no significant between-group differences. Minimal clinically important difference responder rates were high (>85%) for both procedures; the ≥30% ODI threshold favored TJR (90% vs 80%; P = 0.04). CONCLUSIONS:Substantial decreases in back impairment and pain severity were realized in both study groups. However, longitudinal improvement in ODI significantly favored patients treated with TJR. CLINICAL RELEVANCE:Lumbar TJR combines decompression with motion preservation in a single procedure, potentially offering an alternative to fusion in selected patients. The advantage of utilizing a standard posterior operative approach with TJR is that it allows for direct decompression of the neural elements prior to implant placement. LEVEL OF EVIDENCE:2b.

Patients with symptomatic lumbar disc herniation with radiculopathy where there is a large residual annular defect following discectomy are at greater risk of reherniation with symptom recurrence and revision surgery. These patients may benefit from primary annular repair. In 2019, the International Society for the Advancement of Spine Surgery published clinical guidelines supporting the use of bone-anchored annular closure in patients with large annular defects who are at greater risk for recurrent disc herniation. This 2025 update is provided to (1) summarize the current, increased clinical evidence for bone-anchored annular closure with greater follow-up durations and (2) update guidance for coding in light of new diagnostic and upcoming current procedural terminology codes. Based on accumulating clinical evidence, the International Society for the Advancement of Spine Surgery reiterates its position that in patients with symptomatic lumbar disc herniation with radiculopathy undergoing primary discectomy with large (≥6 mm wide) annular defects, bone-anchored annular closure may be used to sustain the treatment benefits of discectomy.

Background: A growing body of clinical evidence has demonstrated that intraosseous minimally invasive basivertebral nerve (BVN) ablation results in significant and durable improvements in vertebrogenic back pain. Thus, it is important to develop, refine and validate new and additional devices to accomplish this procedure. Methods: Using reconstructions of 31 patient computed tomography (CT) scans of the lumbosacral spine (L1-S1), the primary objective was to simulate the intravertebral placement of a novel multitined expandable electrode in bipolar configuration at the targeted ablation site and determine if the proper trajectories could be achieved in order for the device tips to be in the correct position for lesion formation at the BVN plexus. Successful device deployment required that the distance between tips was between 10 mm and 20 mm. Results: The mean distances between device tips ranged from 11.35 mm (L5) to 11.87 mm (L3), and there were no statistically significance differences across the six vertebral levels (F = 0.72, p = 0.61). The percentage of successful intraosseous device placements within the tip distance acceptable range (>= 10 mm to <= 20 mm) was 90% (162 of 180), with no tip-to-tip distances > 20 mm. There was a notable association between decreasing vertebral level and mean degree of angulation between contralateral devices ranging from 50.90 degrees at L1 to 91.51 degrees at S1, and the difference between across the six vertebral levels was significant (F = 89.5, p < 0.01). Conclusion: Feasibility evidence is provided from real world CT imaging data that validates using the multitined electrode for proper intraosseous placement within the vertebral body to effectively ablate the BVN plexus.

While achieving premarket approval from the US Food and Drug Administration represents a significant milestone in the development and commercialization of a Class III medical device, the aftermath endeavor of gaining market access can be daunting. This article provides a case study of the Barricaid annular closure device (Barricaid), a reherniation reduction device, which has been demonstrated to decrease the risk of suffering a recurrent lumbar intervertebral disc herniation. Following Food and Drug Administration approval, clinical adoption has been slow due to barriers to market access, including the perception of low-quality clinical evidence, questionable significance of the medical necessity of the procedure, and imaging evidence of increased likelihood of vertebral endplate changes. The aim of this article is to provide appropriate examination, rationale, and rebuttal of these concerns. Weighing the compendium of evidence, we offer a definition of a separate and unique current procedural terminology code to delineate this procedure. Adoption of this code will help to streamline the processing of claims and support the conduct of research, the evaluation of health care utilization, and the development of appropriate medical guidelines.

Background: Preventing disc degeneration remains a clinical challenge; patients experiencing chronic lumbar discogenic pain have limited treatment options. Minimally invasive intradiscal procedures such as allogeneic nucleus pulposus (NP) injection have the potential to fill the treatment gap between failed conservative care and spine surgery. Objectives: Our study sought to evaluate the magnitude and durability of improvement in back function in patients with chronic lumbar discogenic pain followed for 6 months after a single intradiscal injection of minimally manipulated, off-the-shelf processed NP allograft (VIA Disc NP (R), VIVEX Biologics, Inc.) at up to 2 vertebral levels. Study Design: Single-arm, prospective, multicenter, pilot study. Setting: Academic and private practice outpatient clinics. Methods: A total of 29 patients with symptomatic lumbar discogenic pain refractory to conservative care who had a back function score of 40-80 points on the Oswestry Disability Index (ODI), >= 6 on an 11-point back pain Numeric Rating Scale (NRS-11) and corresponding imaging evidence of disc degeneration were enrolled. A single dose, intradiscal injection of approximately 100 mg of NP allograft mixed with sterile saline was administered to the affected level or levels. Results: The average ODI and NRS-11 improvements between baseline and 6-months postprocedure were 54.8% (95% CI, 41.3-68.3) and 52.9% (95% CI, 34.7-71.1) respectively (P < 0.001). A minimal clinically important difference of >= 30% improvement over baseline was achieved in 79% (22 of 28) and 68% (19 of 28) of patients for ODI and NRS-11, respectively. At 6-months postprocedure, 64% (18 of 28) of patients had an NRS-11 score <= 3. Limitations: This pilot study did not employ a concurrent control group and the clinical follow-up was limited to 6 months. Conclusions: These pilot findings demonstrate the feasibility of treating patients with symptomatic lumbar disc degeneration with a single intradiscal injection of allogeneic NP to provide significant and durable improvements in back function and pain.

Specific clinical diagnostic criteria have established a consensus for defining patients with lumbar discogenic pain. However, if conservative medical management fails, these patients have few treatment options short of surgery involving discectomy often coupled with fusion or arthroplasty. There is a rapidly-emerging research effort to fill this treatment gap with intradiscal therapies that can be delivered minimally-invasively via fluoroscopically guided injection without altering the normal anatomy of the affected vertebral motion segment. Viable candidate products to date have included mesenchymal stromal cells, platelet-rich plasma, nucleus pulposus structural allograft, and other cell-based compositions. The objective of these products is to repair, supplement, and restore the damaged intervertebral disc as well as retard further degeneration. In doing so, the intervention is meant to eliminate the source of discogenic pain and avoid surgery. Methodologically rigorous studies are rare, however, and based on the best clinical evidence, the safety as well as the magnitude and duration of clinical efficacy remain difficult to estimate. Further, we summarize the US Food and Drug Administration's (FDA) guidance regarding the interpretation of the minimal manipulation and homologous use criteria, which is central to designating these products as a tissue or as a drug/device/biologic. We also provide perspectives on the core evidence and knowledge gaps associated with intradiscal therapies, propose imperatives for evaluating effectiveness of these treatments and highlight several new technologies on the horizon.

PURPOSE:Intraoperative bulbocavernosus reflex neuromonitoring has been utilized to protect bowel, bladder, and sexual function, providing a continuous functional assessment of the somatic sacral nervous system during surgeries where it is at risk. Bulbocavernosus reflex data may also provide additional functional insight, including an evaluation for spinal shock, distinguishing upper versus lower motor neuron injury (conus vs. cauda syndromes) and prognosis for postoperative bowel and bladder function. Continuous intraoperative bulbocavernosus reflex monitoring has been utilized to provide the surgeon with an ongoing functional assessment of the anatomical elements involved in the S2-S4 mediated reflex arc including the conus, cauda equina and pudendal nerves. Intraoperative bulbocavernosus reflex monitoring typically includes the electrical activation of the dorsal nerves of the genitals to initiate the afferent component of the reflex, followed by recording the resulting muscle response using needle electromyography recordings from the external anal sphincter.METHODS:Herein we describe a complementary and novel technique that includes recording electromyography responses from the external urethral sphincter to monitor the external urethral sphincter reflex. Specialized foley catheters embedded with recording electrodes have recently become commercially available that provide the ability to perform intraoperative external urethral sphincter muscle recordings.RESULTS:We describe technical details and the potential utility of incorporating external urethral sphincter reflex recordings into existing sacral neuromonitoring paradigms to provide redundant yet complementary data streams.CONCLUSIONS:We present two illustrative neurosurgical oncology cases to demonstrate the utility of the external urethral sphincter reflex technique in the setting of the necessary surgical sacrifice of sacral nerve roots.

Background: The traditional open midline posterior cervical spine fusion procedure has several shortcomings. It can cause soft tissue damage, muscle atrophy, compromise of the lateral masses and painful prominent posterior cervical instrumentation or spinous process if there is dehiscence of the fascia. Additionally, patients frequently experience the rapid development of adjacent segment disease, which can result in the reemergence of debilitating pain and functional impairment. Clinical relevance: Tissue-sparing posterior cervical fusion is an alternative method for treating patients with symptomatic cervical degenerative disc disease. However, widespread clinical adoption has been challenged by ambiguity, misunderstandings and misinterpretations regarding appropriate procedural reimbursement coding. Technological advancement: The tissue-sparing posterior cervical fusion procedure was approved by the US Food and Drug Administration (FDA) in 2018 (CORUS™ Spinal System and CAVUX® Facet Fixation System (CORUS/CAVUX); Providence™ Medical Technology). This technique addresses the concerns with traditional spine fusion methods by achieving the stability and outcomes of posterior cervical fusion without the morbidity associated with significant muscle stripping in the traditional approach. This technology uses specialized implants and instrumentation to perform all of the steps required to facilitate bone fusion and provide stability while minimizing tissue disruption. The technique involves extensive bone preparation for fusion and placement of specialized stabilization implants that span the facet joint, promoting natural bone growth and fusion while reducing the need for extensive exposure. This procedure provides an effective, less invasive solution for patients with cervical degenerative disc disease. Reimbursement and coding clarity: The article provides a comprehensive rationale for appropriate reimbursement coding for tissue-sparing posterior cervical fusion. This is a critical aspect for the adoption and accessibility of medical technologies. This information is crucial for practitioners and healthcare administrators, ensuring that innovative procedures are accurately coded and reimbursed. Procedural details and clinical evidence: By detailing the procedural steps, instruments used and the physiological basis for the procedure, this article serves as a valuable educational resource for spine surgeons and payers to appropriately code for this procedure. Conclusions: The description of work for CORUS/CAVUX is equivalent to the current surgical standard of lateral mass screw fixation with decortication and onlay posterior grafting to facilitate posterior fusion. Thus, it is recommended that CPT codes 22600/22840 be used, as they best reflect the surgical approach, instrumentation, decortication, posterior cervical fusion and bone grafting procedures.

Background:Total joint replacement (TJR) of the lumbar spine is a revolutionary procedure that couples the clinical benefits of neural decompression with preservation of natural motion and sagittal balance at the operative level. The TJR procedure involves reconstruction of the entire motion segment using a posterior bilateral transforaminal approach to access the disc space. The TJR implant (MOTUS, 3Spine, Chattanooga, TN, USA) replaces the function of the intervertebral disc and facet joints, performing biomechanically as a new articulation for the resected, degenerated disc and facets. The implant has been optimized to simulate the kinematic characteristics of the three-joint complex. Case Description:Two male patients, ages 32 and 38 years, underwent the first TJR procedures in 2007 in South Africa. Both patients had imaging evidence of advanced spinal degeneration with unremitting back and leg pain refractory to conservative management. Symptom amelioration was achieved postoperatively with markedly reduced pains scores and improved function at clinical follow-up. Both cases were recently re-examined after 16 years and the patients reported that the procedure significantly changed their lives. Neither believes they have a lingering back condition and they have been able to fully participate in all functions related to work, family and recreation. There was little to no imaging evidence of adjacent segment disease or arthritic changes at this long-term follow-up interval. Conclusions:After 16 years of clinical follow-up, the implant continues to function normally, without evidence of adjacent segment degeneration and both patients continue to enjoy activities of daily living without back or leg pain or other functional impairments.