Seven years follow-up for total lumbar facet joint replacement (TOPS) in the management of lumbar spinal stenosis and degenerative spondylolisthesis

One- and 2-year outcomes of lumbar facet arthroplasty versus spinal fusion in young (<65 years) and old (≥65 years) patients for the treatment of degenerative spondylolisthesis and stenosis

Background

Facet arthroplasty, an alternative to lumbar fusion, offers stabilization and preserves range of motion. This subanalysis of the TOPS IDE trial (FDA #G160168) compared facet arthroplasty, using the TOPS device, with a standard single-level transforaminal lumbar interbody fusion (TLIF) in patients stratified by age (<65 and ≥65 years) with symptomatic grade 1 degenerative spondylolisthesis with moderate to severe spinal stenosis at L2-5.

Methods

Patient-reported outcomes (PROMS), including Oswestry disability index (ODI), visual analog pain scales (VAS), and Zurich claudication questionnaires (ZCQ), were assessed at baseline and multiple postoperative timepoints. Radiographic evaluation of flexion/extension range of motion (ROM) occurred at baseline, 12 months, and 24 months. Data were analyzed following an intention-to-treat model. Significance was defined as p<.05.

Results

About 299 patients were included (TOPS=206, TLIF=93). The groups were similar at baseline. At 2 years, the TOPS group had a greater proportion of patients report ≥15-point improvement for ODI (93.8% versus 77.1%, p=.011) and ≥20-point improvement for VAS back (84.4% versus 61.8%, p=.014). At 1 year, TOPS group had a greater proportion of patients report clinically significant improvements in all ZCQ categories (91.6% versus 78.5%, p=.012). In patients <65 years, the TOPS group had improved PROMS compared to TLIF at 2 years; however, these differences were less pronounced in patients ≥65 years old. The TOPS groups preserved more ROM at 12 (2.8° 95%CI [1.87; 3.74], p<.0001) and 24 (2.99° 95%CI [1.82; 4.15], p<.0001) months compared to TLIF. ROM was similarly preserved in patients aged <65 and ≥65. The rate of adverse events did not differ significantly between treatment groups.

Conclusions

Facet arthroplasty preserves more ROM in all ages and leads to improved PROMS compared to TLIF, particularly in younger patients.

Treatment of Lumbar Degenerative Disease with a Novel Interlaminar Screw Elastic Spacer Technique: A Finite Element Analysis

A novel interlaminar elastic screw spacer technique was designed to maintain lumbar mobility in treating lumbar degenerative diseases. A validated finite element model of L4/5 was used to establish an ISES-1/2 model and an ISES-1/3 model based on different insertion points, a unilateral fixation model and a bilateral fixed model based on different fixation methods, and a Coflex-F model based on different implants. The elastic rods were used to fix screws. Under the same mechanical conditions, we compared the biomechanical characteristics to investigate the optimal entry point for ISES technology, demonstrate the effectiveness of unilateral fixation, and validate the feasibility of the ISES technique. Compared to ISES-1/3, the ISES-1/2 model had lower intradiscal pressure, facet cartilage stress, and posterior structural stress. Compared to the ISES-BF model, the ISES-UF model had lower intervertebral pressure, larger mobility, and smaller stress on the posterior structures. The ISES model had a similar intervertebral pressure and limitation of extension as the Coflex-F model. The ISES model retained greater mobility and reduced the stress on the facet cartilage and posterior structure compared with the Coflex-F model. Our study suggests that the ISES technique is a promising treatment of lumbar degenerative diseases, especially those with osteoporosis.

A Prospective Study of Lumbar Facet Arthroplasty in the Treatment of Degenerative Spondylolisthesis and Stenosis: Results from the Total Posterior Spine System (TOPS) IDE Study

STUDY DESIGN

Prospective randomized Food and Drug Administration investigational device exemption clinical trial.

OBJECTIVE

The purpose of the present study is to report the 1-year clinical and radiographic outcomes and safety profile of patients who underwent lumbar facet arthroplasty through implantation of the Total Posterior Spine System (TOPS) device.

SUMMARY OF BACKGROUND DATA

Lumbar facet arthroplasty is one proposed method of dynamic stabilization to treat grade-1 spondylolisthesis with stenosis; however, there are currently no Food and Drug Administration-approved devices for facet arthroplasty.

METHODS

Standard demographic information was collected for each patient. Radiographic parameters and patient-reported outcome measures were assessed preoperatively and at regular postoperative intervals. Complication and reoperation data were also collected for each patient.

RESULTS

At the time of this study, 153 patients had undergone implantation of the TOPS device. The mean surgical time was 187.8 minutes and the mean estimated blood loss was 205.7cc. The mean length of hospital stay was 3.0 days. Mean Oswestry Disability Index, Visual Analog Score leg and back, and Zurich Claudication Questionnaire scores improved significantly at all postoperative time points ( P >0.001). There were no clinically significant changes in radiographic parameters, and all operative segments remained mobile at 1-year follow-up. Postoperative complications occurred in 11 patients out of the 153 patients (7.2%) who underwent implantation of the TOPS device. Nine patients (5.9%) underwent a total of 13 reoperations, 1 (0.6%) of which was for device-related failure owing to bilateral L5 pedicle screw loosening.

CONCLUSIONS

Lumbar facet arthroplasty with the TOPS device demonstrated a statistically significant improvement in all patient-reported outcome measures and the ability to maintain motion at the index level while limiting sagittal translation with a low complication rate.

Prospective, randomized controlled multicenter study of posterior lumbar facet arthroplasty for the treatment of spondylolisthesis

OBJECTIVE

The purpose of this study was to evaluate the safety and efficacy of a posterior facet replacement device, the Total Posterior Spine (TOPS) System, for the treatment of one-level symptomatic lumbar stenosis with grade I degenerative spondylolisthesis. Posterior lumbar arthroplasty with facet replacement is a motion-preserving alternative to lumbar decompression and fusion. The authors report the preliminary results from the TOPS FDA investigational device exemption (IDE) trial.

METHODS

The study was a prospective, randomized controlled FDA IDE trial comparing the investigational TOPS device with transforaminal lumbar interbody fusion (TLIF) and pedicle screw fixation. The minimum follow-up duration was 24 months. Validated patient-reported outcome measures included the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain. The primary outcome was a composite measure of clinical success: 1) no reoperations, 2) no device breakage, 3) ODI reduction of ≥ 15 points, and 4) no new or worsening neurological deficit. Patients were considered a clinical success only if they met all four measures. Radiographic assessments were made by an independent core laboratory.

RESULTS

A total of 249 patients were evaluated (n = 170 in the TOPS group and n = 79 in the TLIF group). There were no statistically significant differences between implanted levels (L4-5: TOPS, 95% and TLIF, 95%) or blood loss. The overall composite measure for clinical success was statistically significantly higher in the TOPS group (85%) compared with the TLIF group (64%) (p = 0.0138). The percentage of patients reporting a minimum 15-point improvement in ODI showed a statistically significant difference (p = 0.037) favoring TOPS (93%) over TLIF (81%). There was no statistically significant difference between groups in the percentage of patients reporting a minimum 20-point improvement on VAS back pain (TOPS, 87%; TLIF, 64%) and leg pain (TOPS, 90%; TLIF, 88%) scores. The rate of surgical reintervention for facet replacement in the TOPS group (5.9%) was lower than the TLIF group (8.8%). The TOPS cohort demonstrated maintenance of flexion/extension range of motion from preoperatively (3.85°) to 24 months (3.86°).

CONCLUSIONS

This study demonstrates that posterior lumbar decompression and dynamic stabilization with the TOPS device is safe and efficacious in the treatment of lumbar stenosis with degenerative spondylolisthesis. Additionally, decompression and dynamic stabilization with the TOPS device maintains segmental motion.

Current concepts of spondylosis and posterior spinal motion preservation for radiologists

Spinal fusion is performed to eliminate motion at a degenerated or unstable segment. However, this is associated with loss of motion at the fused levels and increased stress on adjacent levels. Motion-preserving implants have been designed in effort to mitigate the limitations of fusion. This review will focus on posterior spinal motion-preserving technologies. In the cervical spine, laminoplasty is a posterior motion-preserving procedure used in the management of myelopathy/cord compression. In the lumbar spine, motion-sparing systems include interspinous process devices (also referred to as interspinous process spacers or distraction devices), posterior dynamic stabilization devices (also referred to as pedicle screw/rod fixation-based systems), and posterior element replacement systems (also referred to as total facet replacement devices). Knowledge of the intended physiologic purpose, hardware utilized, and complications is important in the assessment of imaging in those who have undergone posterior motion preservation procedures.

Posterior Lumbar Facet Replacement and Arthroplasty

There is an ongoing desire for the development of motion-preserving facet replacement devices as an alternative to rigid fixation in hopes of better preserving the natural kinematics of the lumbar spine. Theoretically, such a construct would simultaneously address pain associated with spinal instability and prevent abnormal load distribution and adjacent segment degeneration. Several such devices have been developed including the Anatomic Facet Replacement System, the Total Facet Arthroplasty System, and the Total Posterior Arthroplasty System. Of these devices, none have yet proven to be more efficacious than rigid fixation for lumbar spinal stenosis, and studies are ongoing.

Mean 5-Year Follow-Up Results of a Facet Replacement Device in the Treatment of Lumbar Spinal Stenosis and Degenerative Spondylolisthesis

OBJECTIVE

Flexible stabilization has been utilized to maintain spinal mobility in patients with early-stage lumbar spinal stenosis (LSS). Previous literature has not yet established any nonfusion solution as a viable treatment option for patients with severe posterior degeneration of the lumbar spine. This feasibility study evaluates the mean 5-year outcomes of patients treated with the Total Posterior Spine System (TOPS) facet replacement system in the surgical management of lumbar spinal stenosis and degenerative spondylolisthesis.

METHODS

Ten patients (2 men, 8 women, mean age: 59.6 years) were enrolled into a non-randomized prospective clinical study. Patients were evaluated with standing anteroposterior, lateral, flexion and extension radiographs and magnetic resonance imaging scans, back and leg pain visual analog scale scores, Oswestry Disability Index, Zurich Claudication Questionnaire and the SF-36 questionnaires, preoperatively, 6 months, 1 year, 2 years, and latest follow-up at a mean of 5 years postoperatively (range: 55-74 months). Flexion and extension standing lumbar spine radiographs were obtained at 2 years to assess range of motion at the stabilized segment.

RESULTS

The clinical outcome scores for the cohort improved significantly across all scoring systems. Radiographs at 2 years did not reveal any loss of position or loosening of metal work. There were 2 incidental durotomies and no failures at 5 years, with no patient requiring revision surgery.

CONCLUSIONS

The TOPS implant maintains clinical improvement and motion in the surgical management of LSS and spondylolisthesis, suggesting that it can be considered an option for these indications.

Intervertebral disc degeneration and regeneration: a motion segment perspective

Back and neck pain have become primary reasons for disability and healthcare spending globally. While the causes of back pain are multifactorial, intervertebral disc degeneration is frequently cited as a primary source of pain. The annulus fibrosus (AF) and nucleus pulposus (NP) subcomponents of the disc are common targets for regenerative therapeutics. However, disc degeneration is also associated with degenerative changes to adjacent spinal tissues, and successful regenerative therapies will likely need to consider and address the pathology of adjacent spinal structures beyond solely the disc subcomponents. This review summarises the current state of knowledge in the field regarding associations between back pain, disc degeneration, and degeneration of the cartilaginous and bony endplates, the AF-vertebral body interface, the facet joints and spinal muscles, in addition to a discussion of regenerative strategies for treating pain and degeneration from a whole motion segment perspective.

Total Posterior Spinal Arthroplasty Systems for Dynamic Stability

Degenerative disease of the lumbar spine commonly develops with age and can cause debilitating pain or neurologic deficits. When minimally invasive treatments and pain management interventions fail to provide relief, the traditional treatment has consisted of decompression surgery followed by the possible need for lumbar fusion. A mechanical implant device, known as a Total Posterior Spine (TOPS) System, has been introduced as a potential dynamic alternative to fusion surgery following decompression. The device is a dynamic posterior arthroplasty via pedicle screw insertion that maintains mobility, flexibility, and range of motion by providing multiaxial, three-column stabilization. While currently approved for use in Europe, the device is undergoing clinical trials in the United States to determine efficacy and potential complications. This paper provides a comprehensive narrative review of this technique's mechanism, early clinical outcomes, and considerations for patient selection. A review of the literature identified both positive results and adverse effects. While TOPS' use shows excellent potential, additional prospective trials are needed to determine this system's long-term complications.

Facet Joint Replacement: Intermediate- and Long-Term Outcome in a Large Case Series

BACKGROUND

 The long-term outcome of facet joint replacement (FJR) still is to be proven.

METHODS

 We present a prospective case series of 26 (male-to-female ratio of 1:1; mean age: 61 years) patients undergoing FJR with a follow-up of at least 1 year (range: 12-112; mean: 67 months). Visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and the 12-Item Short Form Health Survey (SF-12) were applied pre- and postoperatively (after 3, 6, and 12 months) as well as at the last follow-up (N = 24). Using X-rays of the lumbar spine (N = 20), the range of motion (ROM) and disk height in the indicator and adjacent levels were assessed.

RESULTS

 FJR was performed at L3/L4 (N = 7), L4/L5 (N = 17), and L5/S1 (N = 2). Mean VAS (mm) for back pain decreased from 71 to 18, mean VAS for right leg pain from 61 to 7, and from 51 to 3 for the left leg. Mean ODI dropped from 51 to 22% (for all p < 0.01). Eighty seven percent of patients were satisfied and pretreatment activities were completely regained in 78.3% of patients. Disk height at the indicator and adjacent levels and ROM at the indicator segment and the entire lumbar spine were preserved. No loosening of implants was observed. Explantation of FJR and subsequent fusion had to be performed in four cases (15.4%).

CONCLUSIONS

 In selected cases, long-term results of FJR show good outcome concerning pain, quality of life, preservation of lumbar spine motion, and protection of adjacent level.

Long-term results for total lumbar facet joint replacement in the management of lumbar degenerative spondylolisthesis

OBJECTIVE

The authors evaluated the long-term clinical outcome of a total posterior arthroplasty system in the surgical treatment of lumbar spinal stenosis with degenerative spondylolisthesis.

METHODS

Between June 2006 and July 2007, 10 patients with neurogenic claudication due to spinal stenosis and single-level degenerative spondylolisthesis were enrolled in a nonrandomized prospective clinical study. The patients were evaluated with radiographs and MRI scans, the visual analog scale (VAS) for back and leg pain, the Oswestry Disability Index (ODI), and the SF-36 health survey preoperatively and at 6 weeks, 3 months, 6 months, 1 year, 2 years, 3 years, 7 years, and 11 years postoperatively.

RESULTS

The mean VAS score for leg pain dropped from 83.5 before surgery to 13 at 6 weeks and 17 at 11 years after surgery. The mean VAS score for back pain dropped from 56.2 preoperatively to 12.5 at 6 weeks and 14 at 11 years after surgery. The mean ODI score decreased from 49.1 preoperatively to 13.5 at 6 weeks and 16 at 11 years after surgery. MRI at 11 years demonstrated stenosis adjacent to the stabilized segment in one patient. This patient was not symptomatic. The authors did not find evidence of progression of the spondylolisthesis in any of the cases. In one patient, conversion to posterolateral fusion was performed due to an early device malfunction.

CONCLUSIONS

The results of this 11-year follow-up study demonstrate that, in patients with spinal stenosis and degenerative spondylolisthesis, decompression and posterior arthroplasty maintain clinical improvement and radiological stability.

Future Studies and Directions for the Optimization of Outcomes for Lumbar Spondylolisthesis

Randomized prospective studies show clear benefits for operative versus nonoperative management of symptomatic lumbar spondylolisthesis, but there is no universally accepted surgical treatment. This article presents options for surgical management of lumbar spondylolisthesis, reviews the clinical trials delineating the role and type of surgical intervention, and explores the directions of future investigations. The next decade will add further clarity to the surgical management of spondylolisthesis, not by randomized prospective trials, but by surgical registries. The power of "big data" offered by registries will likely become the vehicle best suited to amass data on current and novel therapies.

Facet Joints of the Spine: Structure–Function Relationships, Problems and Treatments, and the Potential for Regeneration

The zygapophysial joint, a diarthrodial joint commonly referred to as the facet joint, plays a pivotal role in back pain, a condition that has been a leading cause of global disability since 1990. Along with the intervertebral disc, the facet joint supports spinal motion and aids in spinal stability. Highly susceptible to early development of osteoarthritis, the facet is responsible for a significant amount of pain in the low-back, mid-back, and neck regions. Current noninvasive treatments cannot offer long-term pain relief, while invasive treatments can relieve pain but fail to preserve joint functionality. This review presents an overview of the facet in terms of its anatomy, functional properties, problems, and current management strategies. Furthermore, this review introduces the potential for regeneration of the facet and particular engineering strategies that could be employed as a long-term treatment.

The segment-dependent changes in lumbar intervertebral space height during flexion-extension motion

Objectives

Many studies have investigated the kinematics of the lumbar spine and the morphological features of the lumbar discs. However, the segment-dependent immediate changes of the lumbar intervertebral space height during flexion-extension motion are still unclear. This study examined the changes of intervertebral space height during flexion-extension motion of lumbar specimens.

Methods

First, we validated the accuracy and repeatability of a custom-made mechanical loading equipment set-up. Eight lumbar specimens underwent CT scanning in flexion, neural, and extension positions by using the equipment set-up. The changes in the disc height and distance between adjacent two pedicle screw entry points (DASEP) of the posterior approach at different lumbar levels (L3/4, L4/5 and L5/S1) were examined on three-dimensional lumbar models, which were reconstructed from the CT images.

Results

All the vertebral motion segments (L3/4, L4/5 and L5/S1) had greater changes in disc height and DASEP from neutral to flexion than from neutral to extension. The change in anterior disc height gradually increased from upper to lower levels, from neutral to flexion. The changes in anterior and posterior disc heights were similar at the L4/5 level from neutral to extension, but the changes in anterior disc height were significantly greater than those in posterior disc height at the L3/4 and L5/S1 levels, from neutral to extension.

Conclusions

The lumbar motion segment showed level-specific changes in disc height and DASEP. The data may be helpful in understanding the physiologic dynamic characteristics of the lumbar spine and in optimising the parameters of lumbar surgical instruments.

Cite this article: M. Fu, Q. Ye, C. Jiang, L. Qian, D. Xu, Y. Wang, P. Sun, J. Ouyang. The segment-dependent changes in lumbar intervertebral space height during flexion-extension motion. Bone Joint Res 2017;6:245–252. DOI: 10.1302/2046-3758.64.BJR-2016-0245.R1.

[Hybrid stabilization technique with spinal fusion and interlaminar device to reduce the length of fusion and to protect symptomatic adjacent segments : Clinical long-term follow-up]

INTRODUCTION

Determination of the extent of spinal fusion for lumbar degenerative diseases is often difficult due to minor pathologies in the adjacent segment. Although surgical intervention is required, fusion seems to be an overtreatment. Decompression alone may be not enough as this segment is affected by multiple factors such as destabilization, low grade degeneration and an unfavorable biomechanical transition next to a rigid construct. An alternative surgical treatment is a hybrid construct, consisting of fusion and implantation of an interlaminar stabilization device at the adjacent level. The aim of this study was to compare long-term clinical outcome after lumbar fusion with a hybrid construct including an interlaminar stabilization device as "topping-off".

MATERIALS AND METHODS

A retrospective analysis of 25 lumbar spinal fusions from 2003 to 2010 with additional interlaminar stabilization device was performed. Through a matched case controlled procedure 25 congruent patients who received lumbar spinal fusion in one or two levels were included as a control group. At an average follow-up of 43 months pre- and postoperative pain, ODI, SF-36 as well as clinical parameters, such as leg and back pain, walking distance and patient satisfaction were recorded.

RESULTS

Pain relief, ODI improvement and patient satisfaction was significantly higher in the hybrid group compared to the control group. SF-36 scores improved in both groups but was higher in the hybrid group, although without significance. Evaluation of walking distance showed no significant differences.

DISCUSSION

Many outcome parameters present significantly better long-term results in the hybrid group compared to sole spinal fusion. Therefore, in cases with a clear indication for lumbar spinal fusion with the need for decompression at the adjacent level due to spinal stenosis or moderate spondylarthrosis, support of this segment with an interlaminar stabilization device demonstrates a reasonable treatment option with good clinical outcome. Also, the length of the fusion construct can be reduced allowing for a softer and more harmonic transition.

The outcome of decompression alone for lumbar spinal stenosis with degenerative spondylolisthesis

PURPOSE

Lumbar spinal stenosis in the presence of degenerative spondylolisthesis is generally treated by means of surgery. The role of lumbar decompression without fusion is not clear. Therefore, the aim of this study was to assess whether patients who undergo decompression alone have a favourable outcome without the need for a subsequent fusion.

METHODS

This is a prospective cohort study with single blinding of 83 consecutive patients with lumbar stenosis and degenerative spondylolisthesis treated by decompression, without fusion, using a spinous process osteotomy. Blinded observers collected pre- and post-operative Oswestry Disability Index (ODI), EuroQol Five Dimensions (EQ-5D), and visual analogue scale (VAS) for back and leg pain scores prospectively. Failures for this study were those patients who required a subsequent lumbar fusion procedure at the decompressed levels. Statistical analysis was performed using paired t test and Mann-Whitney test.

RESULTS

There were 36 males and 47 females with a mean age of 66 years (range 35-82). The mean follow-up was 36 months (range 19-48 months). The mean pre-operative ODI, EQ-5D, and VAS scores were 52 [standard deviation (SD) 18], 0.25 (SD 0.30), and 61 (SD 22), respectively. All mean scores improved post-operatively to 38 (SD 23), 0.54 (SD 0.34) and 36 (SD 27), respectively. There was a statistically significant improvement in all scores (p ≤ 0.0001). Nine patients (11 %) required a subsequent fusion procedure and five patients (6 %) required revision decompression surgery alone.

CONCLUSION

Our study's results show that a lumbar decompression procedure without arthrodesis in a consecutive cohort of patients with lumbar spinal stenosis with degenerative spondylolisthesis had a significant post-operative improvement in ODI, EQ-5D, and VAS. The rate of post-operative instability and subsequent fusion is not high. Only one in 10 patients in this group ended up needing a subsequent fusion at a mean follow-up of 36 months, indicating that fusion is not always necessary in these patients.