Early clinical effects of the Dynesys system plus transfacet decompression through the Wiltse approach for the treatment of lumbar degenerative diseases

Clinical Effect of Minimally Invasive Microendoscopic-Assisted Transforaminal Lumbar Interbody Fusion for Single-Level Lumbar Disc Herniation

OBJECTIVE

This retrospective study aimed to compare the clinical and radiological outcomes of transforaminal lumbar interbody fusion (TLIF) through the Wiltse approach (W-TLIF) vs minimally invasive microendoscopy-assisted transforaminal lumbar interbody fusion (ME-TLIF) in single-segment lumbar disc herniation (LDH).

METHODS

A retrospective study was conducted to study the differences in specific clinical outcomes between single-segment LDH patients receiving W-TLIF and ME-TLIF. Single-segment LDH patients admitted to the Fujian Medical University Union Hospital from March 2015 to June 2018 were included. All the participants were divided into the ME-TLIF group or the W-TLIF group according to their TLIF surgery types. Demographic characteristics, the visual analog score (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) scale, blood loss volume, postoperative drainage, ambulated time, initial postoperative back pain, hospitalization duration, expenses, and improvement rates of patients in the two groups were collected for analysis. Radiographic fusion was ultimately assessed via the Bridwell interbody fusion grading system. All selected patients with TLIF were followed up for 1 year.

RESULTS

Fifty-seven patients were selected, with 26 in the ME-TLIF group and 31 in the W-TLIF group, both of whom were followed up for 1 year. The mean age of the included patients was 53.75 ± 9.313 years, and the sex ratio was indiscrimination. There was no significant difference in demographic data or operating time between the two groups prior to surgery. The blood loss volume (ME-TLIF: 228.5 vs W-TLIF: 681.3), postoperative drainage (ME-TLIF:82.1 ± 23.5 vs W-TLIF: 345.8 ± 65.2), initial postoperative back pain (ME-TLIF: VAS_3 days: 1.96 ± 0.60 VAS_7 days: 1.73 ± 0.53, W-TLIF: VAS_3 days: 2.48 ± 0.51 VAS_7 days: 1.87 ± 0.43), and hospitalization duration (ME-TLIF: 9.04 vs. W-TLIF: 11.29) were all significantly lower in the ME-TILF group (p < 0.05). However, there were no statistical differences between the two groups in VAS, ODI, and JOA at 1 month, 3 months, 6 months, and 1 year postoperatively (p > 0.05). The fusion rates of the two groups showed no notable difference (p > 0.05), while the X-ray exposure time in the ME-TLIF group was significantly longer than in the W-TLIF group (p < 0.05).

CONCLUSIONS

ME-TLIF surgery was an effective and satisfactory surgical technique to manage LDH. Although ME-TLIF increased the operation time and intraoperative fluoroscopic irradiation volume, it could effectively relieve low back pain from early postoperative onset and promote early postoperative recovery compared with W-TLIF.

Preoperative facet joint arthropathy does not impact long-term clinical outcomes after lumbar-stability-preserving decompression and dynesys fixation

To evaluate the impact of the preoperative severity of facet joint arthropathy on long-term functional outcomes and spinopelvic parameters in patients undergoing lumbar-stability-preserving decompression and Dynesys fixation. In this retrospective study, 88 patients undergoing combined surgery at our hospital from 2008 to 2015 were included. The patients were divided into two groups, the less and more than mean degeneration groups, based on preoperative facet joint arthropathy of the index level(s). The clinical outcomes were the Visual Analogue Scale (VAS) score, the Oswestry Disability Index (ODI) score and spinopelvic parameters. The mean follow-up durations for the less and more than mean degeneration groups were 84.83 ± 27.58 and 92.83 ± 20.45 months, respectively. The combined surgery significantly improved VAS and ODI scores, and increased sacral slope (SS) regardless of preoperative arthropathy severity. In addition, facet joint arthropathy at adjacent levels continued to worsen after surgery in both arthropathy severity groups. Preoperative facet joint arthropathy did not influence most long-term clinical outcomes in patients undergoing lumbar-stability-preserving decompression and Dynesys fixation. This combined surgery may be suitable for patients with facet joint arthropathy regardless of disease severity.

Long-Term Outcome of Dynesys Dynamic Stabilization for Lumbar Spinal Stenosis

Background:

Many clinical studies over the past decade have indicated positive outcomes for patients treated with Dynesys dynamic stabilization for lumbar degenerative disease. However, long-term outcomes of Dynesys for lumbar spinal stenosis are rarely reported. The aim of this study was to analyze the long-term clinical and radiologic outcomes for patients with lumbar spinal stenosis treated with Dynesys stabilization.

Methods:

Thirty-eight patients with lumbar spinal stenosis were treated with Dynesys stabilization from July 2008 to March 2010. The minimal duration of follow-up was 72 months. The patients were divided into stenosis and spondylolisthesis groups according to degenerative spondylolisthesis. Clinical outcomes were evaluated using the Oswestry Disability Index (ODI) and visual analog scale (VAS). Radiographic evaluations included range of motion (ROM) and the disc heights of stabilized segments and the upper adjacent segments. We also evaluated the occurrence of radiographic and symptomatic adjacent segment degeneration (ASD).

Results:

There were 23 patients in stenosis group and 15 patients in spondylolisthesis group. The ODI scores were significantly improved at the final follow-up evaluation, as compared to the baseline values (16.1 ± 5.7 vs. 57. 2 ± 14.2, t = 61.41, P < 0.01). The VAS scores for back and leg pain were significantly improved from 4.82 ± 0.89 and 4.04 ± 0.82 preoperatively to 0.93 ± 0.61 and 0.54 ± 0.51 postoperatively (t = 6.59, P < 0.01, and t = 5.91, P < 0.01, respectively). There were no differences between the two groups with respect to VAS and ODI scores. The ROM of stabilized segments decreased significantly from 7.8° ± 2.4° to 4.5° ± 1.5° (t = 7.18, P < 0.05), while the upper adjacent segments increased significantly from 8.3° ± 2.4° to 10.4° ± 2.4° (t = 2.87, P = 0.01). The change in disc height of stabilized segments was not significant (11.9 ± 2.1 preoperatively vs. 12.5 ± 1.5 postoperatively, t = 1.43, P = 0.15), whereas the decrease in disc height of the upper adjacent segments was significant (12.5 ± 2.0 preoperatively vs. 11.0 ± 1.7 postoperatively, t = 2.94, P = 0.01). The occurrence of radiographic and symptomatic ASD was 16% (6/38) and 3% (1/38), respectively.

Conclusions:

Decompression and Dynesys stabilization for lumbar stenosis with or without spondylolisthesis showed good long-term clinical and radiographic results. Lumbar stenosis with or without Grade I spondylolisthesis, particularly in patients <60 years of age with mild-to-moderate lumbar disc degeneration, would be one of the main indications for the Dynesys system.

Short-term effects of minimally invasive dynamic neutralization system for the treatment of lumbar spinal stenosis: An observational study

The aim of the study was to evaluate the safety and short-term effects of dynamic stabilization via minimally invasive system for degenerative lumbar spinal stenosis. Patients with degenerative lumbar spinal stenosis and treated with Transforaminal Lumbar Interbody Fusion via minimally invasive minimally system (mis-TLIF) were served as the control group.From April 2011 to March 2015, 47 patients (29 male, 18 female; mean age 47.6 [range, 26-52] years) with lumbar spinal stenosis were treated with decompression and excision of herniated disk via the minimally invasive system combined with the dynamic fixation technique, and 42 patients as control group with mis-TLIF. Minimally invasive surgeries were performed via the posterior incision approach. The clinical outcomes were evaluated by comparing the Visual Analog Scale (VAS) score, Oswestry Disability Index (ODI) scores, and the ROMs of the adjacent segment before and after surgery. The postoperative complications related to the implants were identified.A total of 83 patients (43 of Dynesys group and 40 of mis-TLIF group) were followed for an average duration of >35 months. Dynesys stabilization resulted in significantly higher preservation of motion at the index level (P < .05), and significantly less hypermobility at the adjacent segments. VAS for the back and leg pain and ODI improved significantly (P < .05) in 2 groups; however, there is no significant difference between the groups. In Dynesys group, 3 cases suffered skin flay necrosis, 1 of them had a wound infection that was treated with washing and drainage combined with antibiotic therapy. Skin flay necrosis were also observed in 2 cases of mis-TLIF group. Reoperation was performed in one case of Dynesys group for rupture of the internal fixation. No rupture of internal fixation was observed in mis-TLIF group.The nonfusion fixation system Dynesys may be used to treat degenerative spinal stenosis without posterior element damage. This surgical technique is safe and effective. However, utilizing higher preservation of motion may lead to the failure of internal fixation.

Comparison of pedicle screw–based dynamic stabilization and fusion surgery in the treatment of radiographic adjacent-segment degeneration: a retrospective analysis of single L5–S1 degenerative spondylosis covering 4 years

OBJECTIVE

Pedicle screw–based dynamic spinal stabilization systems (PDSs) were devised to decrease, theoretically, the risk of long-term complications such as adjacent-segment degeneration (ASD) after lumbar fusion surgery. However, to date, there have been few studies that fully proved that a PDS can reduce the risk of ASD. The purpose of this study was to examine whether a PDS can influence the incidence of ASD and to discuss the surgical coping strategy for L5–S1 segmental spondylosis with preexisting L4–5 degeneration with no related symptoms or signs.

METHODS

This study retrospectively compared 62 cases of L5–S1 segmental spondylosis in patients who underwent posterior lumbar interbody fusion (n = 31) or K-Rod dynamic stabilization (n = 31) with a minimum of 4 years' follow-up. The authors measured the intervertebral heights and spinopelvic parameters on standing lateral radiographs and evaluated preexisting ASD on preoperative MR images using the modified Pfirrmann grading system. Radiographic ASD was evaluated according to the results of radiography during follow-up.

RESULTS

All 62 patients achieved remission of their neurological symptoms without surgical complications. The Kaplan-Meier curve and Cox proportional-hazards model showed no statistically significant differences between the 2 surgical groups in the incidence of radiographic ASD (p > 0.05). In contrast, the incidence of radiographic ASD was 8.75 times (95% CI 1.955–39.140; p = 0.005) higher in the patients with a preoperative modified Pfirrmann grade higher than 3 than it was in patients with a modified Pfirrmann grade of 3 or lower. In addition, no statistical significance was found for other risk factors such as age, sex, and spinopelvic parameters.

CONCLUSIONS

Pedicle screw–based dynamic spinal stabilization systems were not found to be superior to posterior lumbar interbody fusion in preventing radiographic ASD (L4–5) during the midterm follow-up. Preexisting ASD with a modified Pfirrmann grade higher than 3 was a risk factor for radiographic ASD. In the treatment of degenerative diseases of the lumbosacral spine, the authors found that both of these methods are feasible. Also, the authors believe that no extra treatment, other than observation, is needed for preexisting degeneration in L4–5 without any clinical symptoms or signs.

Complications associated with the Dynesys dynamic stabilization system: a comprehensive review of the literature

The Dynesys dynamic stabilization system is an alternative to rigid instrumentation and fusion for the treatment of lumbar degenerative disease. Although many outcomes studies have shown good results, currently lacking is a comprehensive report on complications associated with this system, especially in terms of how it compares with reported complication rates of fusion. For the present study, the authors reviewed the literature to find all studies involving the Dynesys dynamic stabilization system that reported complications or adverse events. Twenty-one studies were included for a total of 1166 patients with a mean age of 55.5 years (range 39-71 years) and a mean follow-up period of 33.7 months (range 12.0-81.6 months). Analysis of these studies demonstrated a surgical-site infection rate of 4.3%, pedicle screw loosening rate of 11.7%, pedicle screw fracture rate of 1.6%, and adjacent-segment disease (ASD) rate of 7.0%. Of studies reporting revision surgeries, 11.3% of patients underwent a reoperation. Of patients who developed ASD, 40.6% underwent a reoperation for treatment. The Dynesys dynamic stabilization system appears to have a fairly similar complication-rate profile compared with published literature on lumbar fusion, and is associated with a slightly lower incidence of ASD.

Nonfusion Does Not Prevent Adjacent Segment Disease: Dynesys Long-term Outcomes With Minimum Five-year Follow-up

STUDY DESIGN

Case series.

OBJECTIVE

The aim of this study was to determine the relationship between fusion and adjacent segment disease via Dynesys long-term outcomes.

SUMMARY OF BACKGROUND DATA

Dynesys is a dynamic stabilization system meant to improve symptoms by stabilizing the spine without fusion and avoiding the development of adjacent segment disease. However, few studies have evaluated long-term outcomes.

METHODS

All patients were operated on with Dynesys from 2006 to 2009 by a single surgeon at a single institution. We prospectively collected 18 variables among the following categories: patient characteristics, comorbidities, surgical indications, and OR variables. We analyzed two primary endpoints: solid fusion on X-ray and clinical adjacent segment disease (ASD) both at 5 years. Secondary endpoints were time to fusion, time to ASD, reoperation, Oswestry disability index (ODI), and visual analogue scale (VAS) leg pain. We conducted a multivariate analysis via the random forest method. Mann-Whitney U test and Fisher exact test were then used to qualify relationship between variables.

RESULTS

We had 52 patients to review in the database. Eight had preexisting ASD. Mean follow-up was 92 months (median 87 months). Fifteen had ASD (29%) during follow-up at a mean 45 months (Median 35 months). Nine had a solid fusion (17%), 2 of which also had ASD. Mean time to fusion was 65 months (median 71 months). Differences in improvement of ODI (P = 0.005) and VAS leg pain (P = 0.002) were significant favoring patients without ASD. The multivariate analysis revealed four variables associated with ASD: prior ASD (OR 11.3, P = 0.005), neurological deficit (OR 8.5, P = 0.018), revision OR (OR 8.5, P = 0.018), and multilevel degeneration (OR 0.184, P = 0.026). No variable was associated with fusion.

CONCLUSION

Dynesys was associated with a high rate of ASD over long-term follow-up despite maintaining a low fusion rate. Prior ASD was the strongest predictor of progressive ASD.

LEVEL OF EVIDENCE

3.