Intraoperative findings, complications, and short-term results after lumbar microdiscectomy with or without implantation of annular closure device

Recent advances in the repair of degenerative intervertebral disc for preclinical applications

The intervertebral disc (IVD) is a load-bearing, avascular tissue that cushions pressure and increases flexibility in the spine. Under the influence of obesity, injury, and reduced nutrient supply, it develops pathological changes such as fibular annulus (AF) injury, disc herniation, and inflammation, eventually leading to intervertebral disc degeneration (IDD). Lower back pain (LBP) caused by IDD is a severe chronic disorder that severely affects patients' quality of life and has a substantial socioeconomic impact. Patients may consider surgical treatment after conservative treatment has failed. However, the broken AF cannot be repaired after surgery, and the incidence of re-protrusion and reoccurring pain is high, possibly leading to a degeneration of the adjacent vertebrae. Therefore, effective treatment strategies must be explored to repair and prevent IDD. This paper systematically reviews recent advances in repairing IVD, describes its advantages and shortcomings, and explores the future direction of repair technology.

The effect of low preoperative platelet count on adverse outcomes following lumbar microdiscectomy

Background

Low preoperative platelet count, or thrombocytopenia, has previously been associated with increased complications in elective spine surgeries. No other study has investigated the effects of abnormal coagulation profiles on postoperative outcomes specific to lumbar microdiscectomy (MLD) using a propensity matched cohort.

Methods

Patient data was retrospectively retrieved from the National Surgical Quality Improvement Program database using Current Procedural Terminology (CPT) code 63030 to isolate patients who solely underwent MLD. Data was collected from 2010 to 2019 and included preoperative, perioperative, and 30-day postoperative variables. Patients were grouped into four platelet categories for ANOVA analysis and pairwise comparisons: Severe Thrombocytopenia (≤100), Thrombocytopenia (101-150), Moderate (151-199), and Normal (200-450). Variables that were significant in the univariate analysis were used in the multivariate analysis to determine the likelihood of experiencing adverse postoperative events – unplanned return to the operating room and surgical site infection. A propensity matched analysis was performed to control for confounding variables.

Results

A total of 64,747 patients were identified within the 10-year period. The results of the multivariate analysis and the propensity matched analysis showed no significant differences in low preoperative platelet count as an independent predictor of experiencing a return to the operating room or surgical site infection. Furthermore, patients who had diabetes, history of smoking, or had emergency cases were associated with a high likelihood of experiencing these negative adverse events.

Conclusion

Thrombocytopenia does not appear to independently predict return to the operating room or postoperative infection following MLD. Proper preoperative management strategies should be implemented to monitor comorbidity burden which would otherwise influence adverse outcomes in patients with thrombocytopenia undergoing MLD.

Effectiveness of an Annular Closure Device to Prevent Recurrent Lumbar Disc Herniation: A Secondary Analysis With 5 Years of Follow-up

IMPORTANCE

Patients with large annular defects following lumbar microdiscectomy for disc herniation are at increased risk for symptomatic recurrence and reoperation.

OBJECTIVE

To determine whether a bone-anchored annular closure device in addition to lumbar microdiscectomy resulted in lower reherniation and reoperation rates vs lumbar microdiscectomy alone.

DESIGN, SETTING, AND PARTICIPANTS

This secondary analysis of a multicenter randomized clinical trial reports 5-year follow-up for enrolled patients between December 2010 and October 2014 at 21 clinical sites. Patients in this study had a large annular defect (6-10 mm width) following lumbar microdiscectomy for treatment of lumbar disc herniation. Statistical analysis was performed from November to December 2020.

INTERVENTIONS

Lumbar microdiscectomy with additional bone-anchored annular closure device (device group) or lumbar microdiscectomy only (control group).

MAIN OUTCOMES AND MEASURES

The incidence of symptomatic reherniation, reoperation, and adverse events as well as changes in leg pain, Oswestry Disability Index, and health-related quality of life when comparing the device and control groups over 5 years of follow-up.

RESULTS

Among 554 randomized participants (mean [SD] age: 43 [11] years; 327 [59%] were men), 550 were included in the modified intent-to-treat efficacy population (device group: n = 272; 270 [99%] were White); control group: n = 278; 273 [98%] were White) and 550 were included in the as-treated safety population (device group: n = 267; control group: n = 283). The risk of symptomatic reherniation (18.8% [SE, 2.5%] vs 31.6% [SE, 2.9%]; P < .001) and reoperation (16.0% [SE, 2.3%] vs 22.6% [SE, 2.6%]; P = .03) was lower in the device group. There were 53 reoperations in 40 patients in the device group and 82 reoperations in 58 patients in the control group. Scores for leg pain severity, Oswestry Disability Index, and health-related quality of life significantly improved over 5 years of follow-up with no clinically relevant differences between groups. The frequency of serious adverse events was comparable between the treatment groups. Serious adverse events associated with the device or procedure were less frequent in the device group (12.0% vs 20.5%; difference, -8.5%; 95% CI, -14.6% to -2.3%; P = .008).

CONCLUSIONS AND RELEVANCE

In patients who are at high risk of recurrent herniation following lumbar microdiscectomy owing to a large defect in the annulus fibrosus, this study's findings suggest that annular closure with a bone-anchored implant lowers the risk of symptomatic recurrence and reoperation over 5 years of follow-up.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01283438.