Tag: polyetheretherketone

Posted on

Which interbody device minimized nonunion, subsidence, and reoperation after anterior cervical discectomy and fusion?

J Neurosurg Spine 43:453–463, 2024

This meta-analysis found that allograft spacers in anterior cervical discectomy and fusion (ACDF) result in lower nonunion and revision rates compared to PEEK cages, with no significant difference in subsidence risk. Allograft offers enhanced fusion and minimizes revision without increasing subsidence.

• Allograft and PEEK cages are the most commonly used interbody spacers in anterior cervical discectomy and fusion (ACDF), replacing autograft due to lower donor site morbidity.

• This meta-analysis included 10 studies with 1462 patients comparing allograft and PEEK cages for ACDF, analyzing nonunion, subsidence, and reoperation rates.

• Allograft showed a significantly lower rate of nonunion than PEEK cages (OR 0.33, p = 0.01), indicating better fusion outcomes.

• Reoperation due to nonunion was significantly higher with PEEK cages compared to allograft (OR 0.28, p < 0.01), but overall reoperation rates for any cause were not significantly different.

• No significant difference was found in the incidence or amount of subsidence between allograft and PEEK cages.

• Allograft’s osteoconductive properties likely contribute to its higher fusion rate, while PEEK cages may lead to fibrous interface formation, reducing solid fusion.

• Meta-regression showed no significant effect of smoking, age, or number of fused levels on nonunion rates.

• Conclusion: Allograft is advantageous over PEEK cages in ACDF due to higher fusion rates and lower revision risk, without increasing subsidence

Posted on

Predictors of subsidence after lateral lumbar interbody fusion

J Neurosurg Spine 37:183–187, 2022

Lateral lumbar interbody fusion (LLIF) facilitates the restoration of disc height and the indirect decompression of neural elements. However, these benefits are lost when the graft subsides into the adjacent endplates. The factors leading to subsidence after LLIF are poorly understood. This article presents a case series of patients who underwent LLIF and reports factors correlating with subsidence.

METHODS A retrospective review of a consecutive, prospectively collected, single-institution database of patients who underwent LLIF over a 29-month period was performed. The degree of subsidence was measured on the basis of postoperative imaging. The timing of postoperative subsidence was determined, and intraoperative fluoroscopic images were reviewed to determine whether subsidence occurred as a result of endplate violation. The association of subsidence with age, sex, cage size and type, bone density, and posterior instrumentation was investigated.

RESULTS One hundred thirty-one patients underwent LLIF at a total of 204 levels. Subsidence was observed at 23 (11.3%) operated levels. True subsidence, attributable to postoperative cage settling, occurred for 12 (5.9%) of the levels; for the remaining 11 (5.4%) levels, subsidence was associated with intraoperative endplate violation noted on fluoroscopy during cage placement. All subsidence occurred within 12 weeks of surgery. Univariate analysis showed that the prevalence of true subsidence was significantly lower among patients with titanium implants (0 of 55; 0%) than among patients with polyetheretherketone cages (12 of 149; 8.1%) (p = 0.04). In addition, the mean ratio of graft area to inferior endplate area was significantly lower among the subsidence levels (0.34) than among the nonsubsidence levels (0.42) (p < 0.01). Finally, subsidence among levels with posterior fixation (4.4% [6/135]) was not significantly different than among those without posterior fixation (8.7% [6/69]) (p = 0.23). Multivariate analysis results showed that the ratio of cage to inferior endplate area was the only significant predictor of subsidence in this study (p < 0.01); increasing ratios were associated with a decreased likelihood of subsidence.

CONCLUSIONS Overall, the prevalence of subsidence after LLIF was low in this clinical series. Titanium cages were associated with a lower prevalence of observed subsidence on univariate analysis; however, multivariate analysis demonstrated that this effect may be attributable to the increased surface area of these cages relative to the inferior endplate area.

Posted on

Risk factors for polyetheretherketone cage subsidence following minimally invasive transforaminal lumbar interbody fusion

Acta Neurochirurgica (2021) 163:2557–2565

Interbody cage subsidence is a postoperative complication leading to poor outcomes after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). This study aimed to identify risk factors of cage subsidence in lumbar spinal diseases after MIS-TLIF using polyetheretherketone (PEEK) cage.

Methods In this retrospective cohort study, plain radiographs and three-dimensional computed tomography (3D-CT) performed 12 months after MIS-TLIF were evaluated, and the risk of cage subsidence was calculated with odds ratio (OR), confidence interval (CI), and logistic regression analysis.

Results A total of 114 patients (mean age, 65 years) and 135 levels were included in this study: 80 (59.3%) with and 55 (40.7%) without cage subsidence. Multifidus atrophy showed the strongest association with PEEK cage subsidence (p < 0.001). Compared to those with normal mass, the odds of PEEK cage subsidence were 76.0 (95% CI: 3.9–1472.9) for severe atrophy. The factors significantly associated with cage subsistence were posterior cage position (OR = 4.2; p = 0.005), cage height ≥ 12 mm (OR = 7.6; p = 0.008), use of an autograft mixed with demineralized bone matrix (DBM) (OR = 5.8; p = 0.002), body mass index (BMI) > 27.5 kg/m2 (OR = 4.2; p = 0.03), and titanium-coated PEEK (Ti-PEEK) cage-type (OR = 38.4, p = 0.02).

Conclusions In MIS-TLIF with a PEEK cage, the factors associated with an increased risk of cage subsidence were higher BMI, increased severity of multifidus muscle atrophy, Ti-coated PEEK cage-type, cage height ≥ 12 mm, use of DBM mixed autograft, and posterior cage position.

Posted on

PEEK versus titanium cages in lateral lumbar interbody fusion: a comparative analysis of subsidence

Neurosurg Focus 49 (3):E10, 2020

The authors have provided a review of radiographic subsidence after lateral lumbar interbody fusion (LLIF) as a comparative analysis between titanium and polyetheretherketone (PEEK) cages. Many authors describe a reluctance to use titanium cages in spinal fusion secondary to subsidence concerns due to the increased modulus of elasticity of metal cages. The authors intend for this report to provide observational data regarding the juxtaposition of these two materials in the LLIF domain.

METHODS A retrospective review of a prospectively maintained database identified 113 consecutive patients undergoing lateral fusion for degenerative indications from January to December 2017. The surgeons performing the cage implantations were two orthopedic spine surgeons and two neurosurgeons. Plain standing radiographs were obtained at 1–2 weeks, 8–12 weeks, and 12 months postoperatively. Using a validated grading system, interbody subsidence into the endplates was graded at these time points on a scale of 0 to III. The primary outcome measure was subsidence between the two groups. Secondary outcomes were analyzed as well.

RESULTS Of the 113 patients in the sample, groups receiving PEEK and titanium implants were closely matched at 57 and 56 patients, respectively. Cumulatively, 156 cages were inserted and recombinant human bone morphogenetic protein– 2 (rhBMP-2) was used in 38.1%. The average patient age was 60.4 years and average follow-up was 75.1 weeks. Subsidence in the titanium group in this study was less common than in the PEEK cage group. At early follow-up, groups had similar subsidence outcomes. Statistical significance was reached at the 8- to 12-week and 52-week follow-ups, demonstrating more subsidence in the PEEK cage group than the titanium cage group. rhBMP-2 usage was also highly correlated with higher subsidence rates at all 3 follow-up time points. Age was correlated with higher subsidence rates in univariate and multivariate analysis.

CONCLUSIONS Titanium cages were associated with lower subsidence rates than PEEK cages in this investigation. Usage of rhBMP-2 was also robustly associated with higher endplate subsidence. Each additional year of age correlated with an increased subsidence risk. Subsidence in LLIF is likely a response to a myriad of factors that include but are certainly not limited to cage material. Hence, the avoidance of titanium interbody implants secondary solely to concerns over a modulus of elasticity likely overlooks other variables of equal or greater importance.

Proudly powered by WordPress