Fueling the debate: Are outcomes better after posterior lumbar interbody fusion (PLIF) or after posterolateral fusion (PLF) in adult patients with low-grade adult isthmic spondylolisthesis?

PLF Versus PLIF and the Fate of L5-S1: Analysis of Operative Nonunion Rates Among 3065 Patients with Lumbar Fusions from a Regional Spine Registry

STUDY DESIGN

A retrospective cohort study with chart review.

OBJECTIVE

The aim of this study was to compare the reoperation rates for symptomatic nonunions (operative nonunion rates) between posterolateral fusions with pedicle screws (PLFs) and posterior interbody fusion with pedicle screws (PLIFs).

SUMMARY OF BACKGROUND DATA

Although radiographic nonunions in PLFs and PLIFs are well documented in the literature, there is no consensus on which technique has lower nonunions. Since some radiographic nonunions may be asymptomatic, a more clinically useful measure is operative nonunions, of which there is minimal research.

METHODS

A retrospective cohort study, using data from the Kaiser Permanente Spine Registry, identified adult patients (≥18 years' old) who had elective single and multilevel PLFs and PLIFs. Descriptive statistics and 2-year incidence rates for operative nonunions were calculated by fusion-level (1-3), fusion type (PLF vs. PLIF), and levels fused (L3 to S1). Time-dependent multivariable Cox-Proportional Hazards regression was used to evaluate nonunion reoperation rates with adjustment for covariates.

RESULTS

The cohort consisted of 3065 patients with PLFs (71.6%) and PLIFs (28.4%). Average age was 65.0 ± 11.7, average follow-up time was 4.8 ± 3.1 years, and average time to operative nonunion was 1.6 (±1.3) years. Single and multilevel incidence rates for nonunions after PLF versus PLIF were similar except for three-level fusions (2.9% [95% confidence interval, CI = 1.0-6.7] vs. 7.1% [95% CI = 0.2-33.9]). In adjusted models, there was no difference in risk of operative nonunions in PLIF compared to PLF (hazard ratio [HR]: 0.8, 95% CI = 0.4-1.6); however, patients with L5-S1 constructs with PLFs had 2.8 times the risk of operative nonunion compared to PLIFs (PLF: HR = 2.8, 95% CI = 1.3-6.2; PLIF: HR = 1.5, 95% CI = 0.4-5.1).

CONCLUSION

In a large cohort of patients with >4 years of follow-up, we found no difference in operative nonunions between PLF and PLIF except for constructs that included L5-S1 in which the risk of nonunion was limited to PLF patients.Level of Evidence: 3.

Different Fusion Approaches for Single-level Lumbar Spondylolysis Have Similar Perioperative Outcomes

STUDY DESIGN

Retrospective cohort study OBJECTIVE.: The aim of this study was to compare perioperative adverse events for patients with lumbar spondylolysis treated with transforaminal lumbar interbody fusion (TLIF), posterior spinal fusion (PSF), combined anterior and posterior fusion (AP fusion), or anterior lumbar interbody fusion (ALIF).

SUMMARY OF BACKGROUND DATA

Previous cohort studies have shown similar long-term outcomes for different surgical approaches for this indication, but potential differences in 30-day perioperative adverse events have not been well characterized.

METHODS

The present study uses data extracted from the American College of Surgeons National Surgical Quality Improvement Database. Patients undergoing fusion with different approaches for lumbar spondylolysis were identified. Propensity score matching was utilized to account for potential differences in demographic and comorbidity factors. Comparisons among perioperative outcomes were then made among the propensity score-matched study groups.

RESULTS

Of 1077 cases of spondylolysis identified, 556 underwent TLIF, 327 underwent PSF, 108 underwent AP fusion, and 86 underwent ALIF. After propensity score matching, there were no differences in the rates of any of the 30-day individual adverse events studied and no differences in the aggregated groupings of any adverse event, serious adverse event, or minor adverse event. There was a significantly increased operative time in the AP fusion group, but there were no differences in hospital length of stay or readmission rates.

CONCLUSION

Because perioperative adverse event rates were similar, even with a slightly longer operative time in the AP fusion group, these findings suggest that surgeon preference and long-term outcomes are better used to determine the recommendation of one surgical approach over another for single level fusions for lumbar spondylolysis.

LEVEL OF EVIDENCE

3.

Comparison of Posterior Lumbar Interbody Fusion Versus Posterolateral Fusion for the Treatment of Isthmic Spondylolisthesis

STUDY DESIGN

Systematic review and meta-analysis.

BACKGROUND

Posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) were widely used in the treatment of lumbar isthmic spondylolisthesis (IS). There was a great controversy over the preferred fusion method.

OBJECTIVE

The purpose of this study is to evaluate the clinical outcomes between PLF and PLIF for the treatment of IS.

MATERIALS AND METHODS

Related studies that compared the clinical effectiveness of PLIF and PLF for the treatment of IS were acquired by a comprehensive search in 4 electronic databases (PubMed, EMBASE, Cochrane Controlled Trial Register, and MEDLINE) from January 1950 through December 2014. Included studies were performed according to eligibility criteria. The main endpoints included: improvement of clinical satisfaction, complication rate, reoperation rate, fusion rate, and reoperation rate.

RESULTS

A total of 9 studies were included in the meta-analysis; 6 were low-quality evidence and 2 were high-quality evidence as indicated by the Jadad scale. Compared with PLIF, PLF patients showed lower fusion rates [P=0.005, odds ratio (OR)=0.29 (0.14, 0.58)] and shorter operation times [P<0.00001, weighted mean difference (WMD)=-0.5(-0.61, -0.39)]. No significant difference was found in the term of postoperative visual analogue scale leg score [P=0.92, WMD=0.02 (-0.39, 0.44)] and visual analogue scale back score [P=0.41, WMD=0.20 (-0.28, 0.68)], blood loss [P=0.39, WMD=121.17 (-152.68, 395.01)], complication rate [P=0.42, OR=1.50 (0.56, 4.03)], postoperative Oswestry Disability Index [P=0.3, WMD=1.09 (-0.97, 3.15)], and postoperative clinical satisfaction [P=0.84, OR=1.06 (0.60, 1.86)].

CONCLUSIONS

In conclusion, our meta-analysis suggested that PLF shows significant lower fusion rate compared with PLIF. Although PLIF had more operation time than PLF, there was no significant difference in global assessment of clinical outcome between the 2 fusion procedures. However, future well-designed, randomized-controlled trials are still needed to further confirm our results.

National Trends in the Surgical Management of Adult Lumbar Isthmic Spondylolisthesis: 1998 to 2011

STUDY DESIGN

A retrospective review.

OBJECTIVE

Isthmic spondylolisthesis (ISY) is a common orthopedic condition. Our objective was to identify trends in the surgical management of adult ISY in the United States and to evaluate trends in the surgical techniques utilized.

SUMMARY OF BACKGROUND DATA

Various surgical approaches have been described for ISY but preferred trends are not known.

METHODS

Using the Nationwide Inpatient Sample (NIS), 47,132 adult patients (≥ 18 years) with ISY undergoing lumbar spine fusion from 1998 to 2011 were identified. Our primary outcome of interest was the national trend in use of anterior (ASF), posterior (PSF), posterior with interbody (P/TLIF), and combined anterior-posterior fusion (A/PSF) surgeries for ISY patients. Poisson regression, modified Wald's test, and linear and logistic regression analysis with P < 0.05 were used for statistical analysis.

RESULTS

The annual rate of fusion surgeries for ISY increased 4.33 times-from 28.31 surgeries in 1998 to 122.69 surgeries per million US adults per year in 2011. Over the study period, annual rates of ASFs increased 2.65 times (P < 0.001), PSFs increased 1.03 times (P = 0.24), P/TLIFs increased 4.33 times (P < 0.001), and A/PSF increased 2.93 times (P < 0.001). In 2010 to 2011, the complication rate was significantly higher for A/PSF (18.86%, P < 0.001). PSFs had a higher complication rate of 3.61% and P/TLIFs (2.58%). The risk of complications was lower for females, elective admissions, and in hospitals in the South. Mean hospitalization charges adjusted to 2011 dollars were significantly higher for A/PSF ($157,560; 95% CI [95% confidence interval]: 14,480-170,360; P <  .001), followed by P/TLIFs ($103,700; 95% CI: 9840-109,030) and PSFs had lower mean hospitalization charges ($87,420; 95% CI: 8210-92,770).

CONCLUSION

Use of fusion for ISY has significantly increased and interbody fusion has become the most preferred approach over the study period. Hospital charges and complications were highest for combined anterior-posterior fusions.

Posterior lumbar interbody fusion and posterolateral fusion: Analogous procedures in decreasing the index of disability in patients with spondylolisthesis

Objective:

The purpose of this study was to evaluate the disability in patients with spondylolisthesis who assigned either to posterolateral fusion (PLF) or posterior lumbar interbody fusion (PLIF) and to compare it between two groups.

Methods:

In a prospective observational study, 102 surgical candidates with low-grade degenerative and isthmic spondylolisthesis enrolled from 2012 to 2014, and randomly assigned into two groups: PLF and PLIF. Evaluation of disability has been done by a questionnaire using Oswestry Disability Index (ODI). The questionnaire was completed by all patients before the surgery, the day after surgery, after 6 months and after 1-year.

Results:

There were no statistically significant differences in terms of age and sex distribution and pre-operation ODI between groups (P > 0.05). Comparison of the mean ODI scores of two groups over the whole study period showed no significant statistical difference (P = 0.074). ODIs also showed no significant differences between two groups the day after surgery, 6^th months and 1-year after surgery (P = 0.385, P = 0.093, P = 0.122 and P = 433) respectively. Analyzing the course of ODI over the study period, showed a significant descending pattern for either of groups (P < 0.0001).

Conclusion:

Both surgical fusion techniques (PLF and PLIF) were efficient to lessen the disability of patients with spondylolisthesis, and none of the fusion techniques were related to a better outcome in terms of disability.

Perioperative outcomes, complications, and costs associated with lumbar spinal fusion in older patients with spinal stenosis and spondylolisthesis

OBJECT

The purpose of this study was to quantify the perioperative outcomes, complications, and costs associated with posterolateral spinal fusion (PSF) among Medicare enrollees with lumbar spinal stenosis (LSS) and/or spondylolisthesis by using a national Medicare claims database.

METHODS

A 5% systematic sample of Medicare claims data (2005-2009) was used to identify outcomes in patients who had undergone PSF for a diagnosis of LSS and/or spondylolisthesis. Patients eligible for study inclusion also required a minimum of 2 years of follow-up and a claim history of at least 12 months prior to surgery.

RESULTS

A final cohort of 1672 patients was eligible for analysis. Approximately half (50.7%) had LSS only, 10.2% had spondylolisthesis only, and 39.1% had both LSS and spondylolisthesis. The average age was 71.4 years, and the average length of stay was 4.6 days. At 3 months and 1 and 2 years postoperatively, the incidence of spine reoperation was 10.9%, 13.3%, and 16.9%, respectively, whereas readmissions for complications occurred in 11.1%, 17.5%, and 24.9% of cases, respectively. At 2 years postoperatively, 36.2% of patients had either undergone spine reoperation and/or received an epidural injection. The average Medicare payment was $36,230 ± $17,020, $46,840 ± $31,350, and $61,610 ± $46,580 at 3 months, 1 year, and 2 years after surgery, respectively.

CONCLUSIONS

The data showed that 1 in 6 elderly patients treated with PSF for LSS or spondylolisthesis underwent reoperation on the spine within 2 years of surgery, and nearly 1 in 4 patients was readmitted for a surgery-related complication. These data highlight several potential areas in which improvements may be made in the effective delivery and cost of surgical care for patients with spinal stenosis and spondylolisthesis.

Fusion techniques for adult isthmic spondylolisthesis: a systematic review

INTRODUCTION

Various fusion techniques have been used to treat lumbar spine isthmic spondylolisthesis (IS) in adults, including anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), posterolateral fusion (PLF), and circumferential fusion. The objective of this study was to evaluate which fusion technique provides the best clinical and radiological outcome for adult lumbar IS.

MATERIALS AND METHODS

A systematic review was performed. MEDLINE databases and reference lists of selected articles were searched. Inclusion criteria stated that the studies had to be controlled and that they compared clinical and radiological outcomes of various fusion techniques for treating adult IS. Exclusion criteria were use of only one treatment and non-English language articles. Two reviewers independently extracted relevant data from each included study. Statistical comparisons were made when appropriate.

RESULTS

Nine studies that compared two surgical approaches to IS were included in this systematic review. Three were prospective studies, and six were retrospective studies. Two studies compared ALIF with instrumented PLF and ALIF with percutaneous pedicle screw fixation, two studies compared ALIF and TLIF, and five studies compared PLIF and PLF. ALIF was superior to other techniques regarding restoration of disc height, segmental lordosis, and whole lumbar lordosis. TLIF had lower complication rates. ALIF combined with PLF showed lower nonfusion rates than other techniques. However, there were no significant differences in clinical outcomes between any two techniques.

CONCLUSION

Compared to other fusion techniques, TLIF shows fewer complications, ALIF shows better sagittal alignment, and circumferential fusion showed better fusion rates. It was difficult to make recommendations about the optimal approach because of the methodological variance in the publications.