Preoperative Risk Factors for Adjacent Segment Degeneration after Two-Level Floating Posterior Fusion at L3-L5

Diabetes increases risk of lumbar spinal fusion complications: association with altered structure of newly formed bone at the fusion site

Diabetes predisposes to spine degenerative diseases often requiring surgical intervention. However, the statistics on the prevalence of spinal fusion success and clinical indications leading to the revision surgery in diabetes are conflicting. The purpose of the presented retrospective observational study was to determine the link between diabetes and lumbar spinal fusion complications using a database of patients (n = 552, 45% male, age 54 ± 13.7 years) residing in the same community and receiving care at the same health care facility. Outcome measures included clinical indications and calculated risk ratio (RR) for revision surgery in diabetes. Paravertebral tissue recovered from a non-union site of diabetic and nondiabetic patients was analyzed for microstructure of newly formed bone. Diabetes increased the RR for revision surgery due to non-union complications (2.80; 95% CI, 1.12-7.02) and degenerative processes in adjacent spine segments (2.26; 95% CI, 1.45-3.53). In diabetes, a risk of revision surgery exceeded the RR for primary spinal fusion surgery by 44% (2.36 [95% CI, 1.58-3.52] vs 1.64 [95% CI, 1.16-2.31]), which was already 2-fold higher than diabetes prevalence in the studied community. Micro-CT of bony fragments found in the paravertebral tissue harvested during revision surgery revealed structural differences suggesting that newly formed bone in diabetic patients may be of compromised quality, as compared with that in nondiabetic patients. In conclusion, diabetes significantly increases the risk of unsuccessful lumbar spine fusion outcome requiring revision surgery. Diabetes predisposes to the degeneration of adjacent spine segments and pseudoarthrosis at the fusion sites, and affects the structure of newly formed bone needed to stabilize fusion.

Comprehensive comparison of three techniques for the treatment of adjacent segment degeneration after lumbar fusion

Purpose

Adjacent segment degeneration (ASD) following lumbar fusion is technically challenging for spine surgeons. Posterolateral open fusion surgery with pedicle screw fixation is an effective way to treat symptomatic ASD with favorable clinical outcomes; however, it is associated with an increased morbidity rate. Therefore, minimally invasive spine surgery is advocated. This study was designed to compare clinical outcomes among patients with symptomatic ASD who underwent percutaneous transforaminal endoscopic discectomy (PTED) with the transforaminal approach, posterior lumbar interbody fusion (PLIF) with cortical bone trajectory screw fixation (CBT-PLIF), and PLIF with traditional trajectory screw fixation (TT-PLIF).

Methods

A retrospective study was conductedon 46 patients (26 men and 20 women; average age 60.8 ± 6.78 years) with symptomatic ASD. The patients were treated with three approaches. The operation time, incision length, time to return to work, complications, and the like were compared among three groups. Intervertebral disc (IVD) space height, angular motion, and vertebral slippage were obtained to assess spine biomechanical stability following surgery. The visual analog scale (VAS) score and Oswestry disability index were evaluated at preoperation and 1-week, 3-month, and the latest follow-ups. Clinical global outcomes were also estimated using modified MacNab criteria.

Results

The operation time, incision length, intraoperative blood loss, and time to return to work for the PTED group were significantly decreased compared with those for the other two groups (P < 0.05). The radiological indicators in the CBT-PLIF group and TT-PLIF group had better biomechanical stability compared with those in the PTED groups at the latest follow-up (P < 0.05). The back pain VAS score in the CBT-PLIF group was significantly decreased compared with those in the other two groups at the latest follow-up (P < 0.05). The good-to-excellent rate was 82.35% in the PTED group, 88.89% in the CBT-PLIF group, and 85.00% in the TT-PLIF group. No serious complications were encountered. Two patients experienced dysesthesia in the PTED group; screw malposition was found in one patient in the CBT-PLIF group. One case with a dural matter tear was observed in the TT-PLIF group.

Conclusion

All three approaches can treat patients with symptomatic ASD efficiently and safely. Functional recovery was more accelerated in the PTED group compared with the other approaches in the short term; CBT-PLIF and TT-PLIF can provide superior biomechanical stability to the lumbosacral spine following decompression compared with PTED; however, compared with TT-PLIF, CBT-PLIF can significantly reduce back pain caused by iatrogenic muscle injury and improve functional recovery. Therefore, superior clinical outcomes were achieved in the CBT-PLIF group compared with the PTED and TT-PLIF groups in the long term.

Incidence and Characteristics of Clinical L5-S1 Adjacent Segment Degeneration after L5 Floating Lumbar Fusion: A Multicenter Study

STUDY DESIGN

Retrospective study.

PURPOSE

This study aimed to evaluate the incidence, characteristics, and risk factors for clinical L5-S1 adjacent segment degeneration (ASD) after L5 floating lumbar fusion.

OVERVIEW OF LITERATURE

ASD is known to occur after lumbar spine fusion at a certain frequency. Several studies on radiological L5- S1 ASD have been reported. However, there are only a few studies on L5-S1 ASD with clinical symptoms, including back pain and/or radiculopathy.

METHODS

In total, 306 patients who received L5 floating lumbar fusion were included in this study. Clinical L5-S1 ASD was defined as newly developed radiculopathy in relation to the L5-S1 segment. Patients' medical records and imaging data were retrospectively analyzed. The risk factors for clinical ASD were assessed by an inverse probability of treatment weighting-adjusted logistic regression analysis.

RESULTS

Clinical L5-S1 ASD occurred in 17 patients (5.6%). The mean onset time of L5-S1 ASD was 12.9±7.5 months after the primary surgery. Among these patients, 10 (58.8%) presented with clinical L5-S1 ASD within 12 months. Reoperation was performed in three patients (1.0%). The severity of L5-S1 disk degeneration did not affect the occurrence of L5-S1 ASD. Logistic regression analysis showed that the number of fusion levels was a significant risk factor for clinical L5-S1 ASD.

CONCLUSIONS

The incidence and characteristics of clinical L5-S1 ASD after L5 floating lumbar fusion were retrospectively investigated. This study established that the number of fusion levels was a significant candidate factor for clinical L5-S1 ASD. Careful clinical follow-up is deemed necessary after L5 floating lumbar fusion surgery, especially for patients who received multiple-level fusions.

Incidence and Risk Factors for Adjacent Segment Disease After Transforaminal Lumbar Interbody Fusion in Patients with Lumbar Degenerative Diseases

PURPOSE

To explore the incidence and risk factors for adjacent segment disease (ASD) in patients with lumbar degenerative diseases after transforaminal lumbar interbody fusion (TLIF).

PATIENTS AND METHODS

The clinical data of 1258 patients who underwent transforaminal lumbar interbody fusion (TLIF) for lumbar degenerative diseases in our hospital from January 2011 to December 2017 were retrospectively analyzed. Patients were divided into the ASD group and non-ASD (N-ASD) group, and the incidence of ASD was calculated. We compared age, BMI, comorbidities, surgery-related parameters, and imaging parameters before surgery between the two groups and used univariate analysis and logistic regression analysis to explore the risk factors for ASD.

RESULTS

Among the 1258 patients who underwent TLIF due to lumbar degenerative diseases, 65 patients developed ASD and received surgical treatment for it, for an incidence of 5.2%. The average onset time of ASD was 68.3±25.1 (20-123) months. Univariate analysis showed that BMI, hypertension, preoperative adjacent segment disc degeneration and preoperative adjacent intervertebral disc height were significantly different between the ASD and N-ASD groups (P< 0.05). Incorporating the above indicators into the logistic regression model, the results showed that BMI and preoperative adjacent intervertebral disc degeneration were risk factors for ASD after TLIF.

CONCLUSION

The incidence of ASD after TLIF in patients with lumbar degenerative disease is approximately 5.2%. High BMI and preoperative adjacent segment disc degeneration are risk factors for ASD after TLIF.

Risk factors for adjacent segment degeneration after posterior lumbar fusion surgery in treatment for degenerative lumbar disorders: a meta-analysis

STUDY DESIGN

A meta-analysis.

OBJECTIVE

We performed a meta-analysis to explore the incidence and risk factors of adjacent segment degeneration (ASD) after posterior lumbar fusion surgery.

METHODS

An extensive search of the literature was performed in English database of PubMed, Embase, and Cochrane Library, and Chinese database of CNKI and WANFANG (up to May 2020). We collected factors including demographic data, surgical factor, and sagittal parameters. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

RESULTS

Finally, 19 studies were included in the final analysis. In our study, the rate of ASD after posterior lumbar fusion surgery was 18.6% (540 of 2896). Our data also showed that mean age, body mass index (BMI), the history of smoking and hypertension, preoperative adjacent disc degeneration, long-segment fusion, preoperative superior facet violation, high lumbosacral joint angle, pre- and post-operative L1-S1 sagittal vertical axis (SVA), post-operative lumbar lordosis (LL), and preoperative pelvic incidence (PI) were associated with the development of ASD. However, gender, history of diabetes, bone mineral density (BMD), preoperative Oswestry Disability Index (ODI) and Japanese Orthopedic Association (JOA), the type of fusion (PLIF vs TLIF), type of bone graft (auto- vs allograft), fusion to S1(vs non-fusion to S1), diagnose (lumbar disc herniation, lumbar spinal stenosis, lumbar spondylolisthesis), preoperative pelvic tilt (PT), LL and sacral slope (SS), post-operative SS, PT and PI were not associated with the development of ASD.

CONCLUSIONS

In our study, many factors were correlated with the risk of ASD after posterior lumbar fusion surgery. We hope this article can provide a reference for spinal surgeons in treatment for lumbar degenerative diseases.