Effectiveness of an annular closure device in a "real-world" population: stratification of registry data using screening criteria from a randomized controlled trial

Is annular repair technique useful for reducing reherniation and reoperation after limited discectomy?

The annular defect because of the primary lumbar disc herniation (LDH) or surgical procedure is considered a primary reason for recurrent herniation and eventually reoperation. Efforts to close the defect with annular repair devices have been attempted several times, but the results were controversial. The present aims to detect whether the annular repair techniques were useful for reducing the re-herniation and re- operation rate. The Pubmed, Cochrane library, and Embase databases were searched to retrieve relevant studies published before January 1, 2021. Continuous variables were compared by calculating the standard difference of the means (SDM), whereas categorical dichotomous variables were assessed using relative risks (RRs). A random-effects model was used if the heterogeneity statistic was significant; otherwise, a fixed-effects model was used. A total of 10 researches were suitable for the meta-analysis, including four different repair techniques and 1907 participates. Compared with the control group, there was no statistical difference with the ODI, VAS-leg, and VAS-back scales for patients treated with the annular repair. However, using an annular repair device was associated with a significant reduction in the re- herniation (p=0.004) and re-operation (0.004) rates. There was no difference between the groups with perioperative complications. However, much more device-related long-term complications happened in the annual repair group (p=0.031) though it still decreased the overall re-operation rate significantly (p=0.006).Our results demonstrated that using an annular repair device was safe and beneficial for reducing re-herniation and re-operation rates.

Predictors of Treatment Success Following Limited Discectomy With Annular Closure for Lumbar Disc Herniation

Background

Previous studies have demonstrated bone-anchored annular closure to significantly reduce reherniation and reoperation rates after lumbar discectomy in patients with large annular defects. It is important to identify the prognostic factors that may be associated with successful treatment. This study aimed to identify predictors of treatment success in patients with lumbar disc herniation treated with limited microdiscectomy supplemented by a bone-anchored annular closure device (ACD).

Methods

This study was a retrospective analysis of 133 consecutive patients with lumbar disc herniation treated with the ACD. Treatment success was defined as ≥24% improvement in visual analog scale (VAS) for back pain, ≥39% improvement in VAS leg pain, and ≥33% in the Oswestry Disability Index (ODI), with the raw ODI score ≤48. Success was calculated at 3, 6, and 12 months after surgery. Potentially predictive outcomes included patient characteristics, operative data, and imaging outcomes, such as disc, facet, and end plate morphology. Logistic regression was used to determine the significant predictive factors for treatment success.

Results

After 3, 6, and 12 months, 97 of 131 (74%), 104 of 129 (81%), and 112 of 126 (89%) patients, respectively, achieved the success criteria. At 3 months follow-up, a higher proportion of younger (17-40 years) versus older (41-65 years) patients met the success criteria (P = .025). On the basis of logistic regression, the following factors were significantly associated with treatment success at 1 or more of the follow-up time points: sex (male), lower body mass index, higher baseline pain and ODI scores, lower grade preoperative disc degeneration, and the absence of a postoperative complication. The rates of index-level recurrent herniation and reoperation were 1.5% and 3.0%, respectively.

Conclusions

This real-world evidence supports a promising benefit-risk profile for augmenting limited microdiscectomy with a bone-anchored ACD and provides some insights into the patient populations that may have a greater chance of realizing significant improvements in pain and function.

Level of Evidence

2 (Cohort study).

International Society for the Advancement of Spine Surgery Policy 2019-Surgical Treatment of Lumbar Disc Herniation with Radiculopathy

Lumbar disc herniation (LDH) is a frequent cause of low back pain and radiculopathy, disability, and diminution in quality of life. While nonsurgical care remains the mainstay of initial treatment, symptoms that persist for prolonged periods of time are well treated with discectomy surgery. A large body of evidence shows that, in patients with unremitting symptoms despite a reasonable period of nonsurgical treatment, discectomy surgery is safe and efficacious. In patients with symptoms lasting greater than 6 weeks, various forms of discectomy (open, microtubular, and endoscopic) are superior to continued nonsurgical treatment. The small but significant proportion of patients with recurrent disc herniation experience less improvement overall than patients who do not experience reherniation after primary discectomy. Lumbar discectomy patients with large annular defects (≥6 mm wide) are at a higher risk for recurrent herniation and revision surgery. Annular closure via a bone-anchored device has been shown to decrease the rate of recurrent disc herniation and associated reoperation in these high-risk patients. After a detailed review of the literature, current clinical evidence supports discectomy (open, microtubular, or endoscopic discectomy) as a medically necessary procedure for the treatment of LDH with radiculopathy in indicated patients. Furthermore, there is new scientific evidence that supports the use of bone-anchored annular closure in patients with large annular defects, who are at greater risk for recurrent disc herniation.

Two-year real-world results of lumbar discectomy with bone-anchored annular closure in patients at high risk of reherniation

PURPOSE

To determine the safety and effectiveness of limited lumbar discectomy with additional implantation of an annular closure device (ACD) among patients at high risk of herniation recurrence treated in routine clinical practice.

METHODS

This was a prospective, single-center study of lumbar discectomy for sciatica caused by intervertebral disc herniation with adjunctive ACD implantation to reduce herniation recurrence risk among high-risk patients with large annular defects. Patients returned for follow-up visits at 6 weeks, 12 weeks, 26 weeks, 1 year, and 2 years. Main outcomes included reoperation, herniation recurrence, back pain severity, leg pain severity, and Oswestry Disability Index (ODI). The minimum important difference was defined as ≥ 20 mm decrease relative to baseline for leg pain severity, ≥ 20 mm decrease for back pain severity, and ≥ 15-point decrease for ODI.

RESULTS

Among 75 high-risk patients (mean age 45 years, 59% female), the cumulative event incidence through 2 years was 4.0% for reoperation and 1.4% for herniation recurrence. Mean leg pain severity decreased from 73 to 6 (p < 0.001), back pain severity decreased from 51 to 13 (p < 0.001), and ODI decreased from 49 to 7 (p < 0.001). The percentage of patients achieving the minimum important difference was 91% for leg pain, 65% for back pain, and 94% for ODI.

CONCLUSION

In patients at high risk of herniation recurrence following limited lumbar discectomy in routine clinical practice, additional implantation of an ACD was safe and reherniation recurrence rates were low at 2-year follow-up, which is favorably compared to reported rates in high-risk patients.

Clinical performance of a bone-anchored annular closure device in older adults

Background: Lumbar discectomy is a common surgical procedure in middle-aged adults. However, outcomes of lumbar discectomy among older adults are unclear. Methods: Lumbar discectomy patients with an annular defect ≥6 mm width were randomized to receive additional implantation with a bone-anchored annular closure device (ACD, n=272) or no additional implantation (controls, n=278). Over 3 years follow-up, main outcomes were symptomatic reherniation, reoperation, and the percentage of patients who achieved the minimum clinically important difference (MCID) without a reoperation for leg pain, Oswestry Disability Index (ODI), SF-36 Physical Component Summary (PCS) score, and SF-36 Mental Component Summary (MCS) score. Results were compared between older (≥60 years) and younger (<60 years) patients. We additionally analyzed data from two postmarket ACD registries to determine consistency of outcomes between the randomized trial and postmarket, real-world results. Results: Among all patients, older patients suffered from crippling or bed-bound preoperative disability more frequently than younger patients (57.9% vs 39.1%, p=0.03). Among controls, female sex, higher preoperative ODI, and current smoking status, but not age, were associated with greater risk of reherniation and reoperation. Compared to controls, the ACD group had lower risk of symptomatic reherniation (HR=0.45, p<0.001) and reoperation (HR=0.54, p=0.008), with risk reductions comparable in older vs younger patients. The percentage of patients achieving the MCID without a reoperation was higher in the ACD group for leg pain (81% vs 72%, p=0.04), ODI (82% vs 73%, p=0.03), PCS (85% vs 75%, p=0.01), and MCS (59% vs 46%, p=0.007), and this benefit was comparable in older versus younger patients. Comparable benefits in older patients were observed in the postmarket ACD registries. Conclusion: Outcomes with lumbar discectomy and additional bone-anchored ACD are superior to lumbar discectomy alone. Older patients derived similar benefits with additional bone-anchored ACD implantation as younger patients.

Closing the Treatment Gap for Lumbar Disc Herniation Patients with Large Annular Defects: A Systematic Review of Techniques and Outcomes in this High-risk Population

Lumbar disc herniation (LDH) is one of the most common spinal pathologies and can be associated with debilitating pain and neurological dysfunction. Discectomy is the primary surgical intervention for LDH and is typically successful. Yet, some patients experience recurrent LDH (RLDH) after discectomy, which is associated with worse clinical outcomes and greater socioeconomic burden. Large defects in the annulus fibrosis are a significant risk factor for RLDH and present a critical treatment challenge. It is essential to identify reliable and cost-effective treatments for this at-risk population. A systematic review of the PubMed and Embase databases was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies describing the treatment of LDH patients with large annular defects. The incidence of large annular defects, measurement technique, RLDH rate, and reoperation rate were compiled and stratified by surgical technique. The risk of bias was scored for each study and for the identification of RLDH and reoperation. Study heterogeneity and pooled estimates were calculated from the included articles. Fifteen unique studies describing 2,768 subjects were included. The pooled incidence of patients with a large annular defect was 44%. The pooled incidence of RLDH and reoperation following conventional limited discectomy in this population was 10.6% and 6.0%, respectively. A more aggressive technique, subtotal discectomy, tended to have lower rates of RLDH (5.8%) and reoperation (3.8%). However, patients treated with subtotal discectomy reported greater back and leg pain associated with disc degeneration. The quality of evidence was low for subtotal discectomy as an alternative to limited discectomy. Each report had a high risk of bias and treatments were never randomized. A recent randomized controlled trial with 550 subjects examined an annular closure device (ACD) and observed significant reductions in RLDH and reoperation rates (>50% reduction). Based on the available evidence, current discectomy techniques are inadequate for patients with large annular defects, leaving a treatment gap for this high-risk population. Currently, the strongest evidence indicates that augmenting limited discectomy with an ACD can reduce RLDH and revision rates in patients with large annular defects, with a low risk of device complications.