Debridement and Interbody Graft Using Titanium Mesh Cage, Posterior Monosegmental Instrumentation, and Fusion in the Surgical Treatment of Monosegmental Lumbar or Lumbosacral Pyogenic Vertebral Osteomyelitis via a Posterior-Only Approach

Pedicle screw insertion into infected vertebrae reduces operative time and range of fixation in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis: a multicenter retrospective cohort study

BACKGROUND

Minimally invasive posterior fixation surgery for pyogenic spondylitis is known to reduce invasiveness and complication rates; however, the outcomes of concomitant insertion of pedicle screws (PS) into the infected vertebrae via the posterior approach are undetermined. This study aimed to assess the safety and efficacy of PS insertion into infected vertebrae in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis.

METHODS

This multicenter retrospective cohort study included 70 patients undergoing minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis across nine institutions. Patients were categorized into insertion and skip groups based on PS insertion into infected vertebrae, and surgical data and postoperative outcomes, particularly unplanned reoperations due to complications, were compared.

RESULTS

The mean age of the 70 patients was 72.8 years. The insertion group (n = 36) had shorter operative times (146 versus 195 min, p = 0.032) and a reduced range of fixation (5.4 versus 6.9 vertebrae, p = 0.0009) compared to the skip group (n = 34). Unplanned reoperations occurred in 24% (n = 17) due to surgical site infections (SSI) or implant failure; the incidence was comparable between the groups. Poor infection control necessitating additional anterior surgery was reported in four patients in the skip group.

CONCLUSIONS

PS insertion into infected vertebrae during minimally invasive posterior fixation reduces the operative time and range of fixation without increasing the occurrence of unplanned reoperations due to SSI or implant failure. Judicious PS insertion in patients with minimal bone destruction in thoracolumbar pyogenic spondylitis can minimize surgical invasiveness.

Comparison of Long-term Follow-Up of n-HA PA66 Cage and PEEK Cage of Lumbar Interbody Fusion in Multi-level Degenerative Lumbar Diseases: A Stepwise Propensity Score Matching Analysis

OBJECTIVE

Previous studies have confirmed that the nanohydroxyapatite/polyamide-66 (n-HA/PA66) cage is an ideal alternative material for degenerative lumbar disease (DLD) comparable to the polyether ether ketone (PEEK) cage due to its similar radiographic fusion, subsidence rate, and clinical results. However, these studies were restricted to one-level surgery. The aim of this study was to analyze the long-term clinical and radiologic outcomes between n-HA PA66 cage and PEEK cage for patients with multi-level degenerative lumbar diseases (DLDs).

METHODS

We retrospectively reviewed all patients who underwent multi-level transforaminal lumbar interbody fusion (TLIF) from June 2010 to December 2016 with a minimum 6-year follow-up. Matched-pair analysis was performed using a 1-to-1 closest neighbor approach to match patients who received an n-HA PA66 cage with those who received a PEEK cage. Clinical outcomes and radiographic evaluations were compared between the two groups. The independent student's t-test and χ2 -test were applied to compare the differences between groups.

RESULTS

At the end of the propensity score matching (PSM) analysis, 48 patients from n-HA/PA66 group were matched to 48 patients in the PEEK group. No significant difference was observed in cage subsidence and bony fusion except for adjacent segment degeneration (ASD). The occurrence of ASD was 14.58% (7/48) in the n-HA/PA 66 group, which was significantly less than that in the PEEK group (33.33% [16/48]) (p = 0.031). Although the intervertebral space height (IH), segmental angle (SA) and lumbar lordosis (LL) significantly increased after surgery in both groups, there was no significant difference at any time point after surgery (p > 0.05). The visual analogue scale (VAS) and Oswestry disability index (ODI) scores significantly improved in both groups at 3m postoperative, 1y postoperative and at final follow-up. However, there were no significant differences in the VAS and ODI score at any time point (p > 0.05). The total complications and re-admission rate were not different between the two groups.

CONCLUSION

Overall, our data suggest that the outcomes of n-HA/PA66 cage group are comparable to those of the PEEK cage group, with a similar high fusion rate and low cage subsidence rate as PEEK cages, except its lower rate of ASD occurrence.

Surgical strategies for spinal infections: A narrative review

The successful operative management of spinal infections necessitates a thoughtful approach. Ideal treatment combines the universal goals of any spine operation, which are decompression of the neural elements and stabilization of instability, with source control and eradication of infection. Techniques to treat infection have evolved independently and alongside advances in implant technology and surgical techniques. This review will seek to outline current thinking on approaches to both primary and secondary spinal infections.

Safety and Efficacy of Polyetheretherketone (PEEK) Cages and Cadaveric Allografts in Transforaminal Lumbar Interbody Fusion (TLIF) for Treating Lumbar Pyogenic Spondylodiscitis

Purpose

There have been many studies in the operative management of pyogenic spondylodiscitis with foreign materials. However, it still remains an issue of debate on whether the allografts may be used in pyogenic spondylodiscitis. This study sought to evaluate the safety and effectiveness of PEEK cages and the cadaveric allograft in transforaminal lumbar interbody fusion (TLIF) for treating lumbar pyogenic spondylodiscitis.

Methods

From January 2012 to December 2019, 56 patients underwent surgery for lumbar pyogenic spondylodiscitis. The posterior debridement of all patients and their fusion with allografts, local bone grafts, and bone chip cages were performed before posterior pedicle screw fusion. An assessment of the residual pain, the grade of neurological injury, and the resolution of infection was conducted on 39 patients. The clinical outcome was evaluated using a visual analog scale (VAS) and the Oswestry Disability Index (ODI), and neurological outcomes were appraised based on Frankel grades. The radiological outcomes were evaluated via focal lordosis, lumbar lordosis, and the state of the fusion.

Results

Staphylococcus aureus and Staphylococcus epidermidis were the most common causative organisms. The mean preoperative focal lordosis was -1.2° (-11.4° to 5.7°), and the mean postoperative focal lordosis increased to 10.3° (4.3°-17.2°). At the final follow-up, there were five cases with subsidence of the cage, no case of recurrence, and no case with cage and screw loosening or migration. The mean preoperative VAS and ODI scores were 8.9 and 74.6%, respectively, and improvements in VAS and ODI were 6.6 ± 2.2 and 50.4 ± 21.3%, respectively. The Frankel grade D was found in 10 patients and grade C in 7. Following the final follow-up, only one patient improved from Frankel grade C to grade D while the others recovered completely.

Conclusion

The PEEK cage and cadaveric allograft combined with local bone grafts is a safe and effective choice for intervertebral fusion and restoring sagittal alignment without increased incidence of relapse for treating lumbar pyogenic spondylodiscitis.

Unidirectional porous beta-tricalcium phosphate as a potential bone regeneration material for infectious bony cavity without debridement in pyogenic spondylitis

An 81-year-old man was initially diagnosed with T11 osteoporotic vertebral fracture. The fractured vertebral body was filled with unidirectional porous beta-tricalcium phosphate (β-TCP) granules, and posterior spinal fixation was conducted using percutaneous pedicle screws. However, the pain did not improve, the inflammatory response increased, and bone destructive changes extended to T10. The correct diagnosis was pyogenic spondylitis with concomitant T11 fragility vertebral fracture. Revision surgery was conducted 2 weeks after the initial surgery, the T10 and T11 pedicle screws were removed, and refixation was conducted. After the revision surgery, the pain improved and mobilization proceeded. The infection was suppressed by the administration of sensitive antibiotics. One month after surgery, a lateral bone bridge appeared at the T10/11 intervertebral level. This increased in size over time, and synostosis was achieved at 6 months. Resorption of the unidirectional porous β-TCP granules was observed over time and partial replacement with autologous bone was evident from 6 months after the revision surgery. Two years and 6 months after the revision surgery, although there were some residual β-TCP and bony defect in the center of the vertebral body, the bilateral walls have well regenerated. This suggested that given an environment of sensitive antibiotic administration and restricted local instability, unidirectional porous β-TCP implanted into an infected vertebral body may function as a resorbable bone regeneration scaffold without impeding infection control even without debridement of the infected bony cavity.

Minimally invasive spine surgery as treatment for persistent infectious lumbar spondylodiscitis: a systematic review and meta-analysis

BACKGROUND

Antibiotic resistant infectious spondylodiscitis (IS) can cause significant morbidity for patients. Open surgical techniques were previously the only option for patients who failed antibiotic therapy. However, advances in minimally invasive surgical techniques may provide a new alternative for some patients.

METHODS

A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to identify studies that reported inflammatory [erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)] and functional outcomes [visual analog scale (VAS)] for patients with antibiotic resistant IS treated with either minimally invasive or open surgery. Searches were preformed using PubMed, Embase, and Scopus from January 2015 to June 2021. Fourteen articles met inclusion criteria. One study was a Level III evidence study and the other 13 included studies were Level IV.

RESULTS

The minimally invasive surgery group showed significantly lower post-operative CRP and VAS pain scores and significantly higher post-operative ESR levels than the open group. All studies included were measured by the Downs and Black tool for potential bias.

DISCUSSION

This study showed that minimally invasive surgery is efficacious in the treatment of antibiotic resistant IS. These outcomes support minimally invasive surgery (MIS) as an effective alternative to previous open surgery techniques in certain patients after failed trails of antibiotic therapy.

One-stage posterior debridement, autogenous spinous process bone graft and instrumentation for single segment lumbar pyogenic spondylitis

To compare the surgical outcomes of autogenous spinous process with iliac bone graft in managing single segment lumbar pyogenic spondylitis (PS) after posterior debridement and instrumentation. We performed a retrospective study for adult patients with single level lumbar PS. 60 patients with single segment lumbar PS underwent one-stage posterior debridement, autogenous bone graft and instrumentations. The patients were divided into Group A (autogenous iliac bone) and Group B (autogenous spinous process). Preoperative Charlson comorbidity index (CCI) was analyzed to assess the comorbidity. Low back pain was evaluated using the visual analog scale (VAS). Neurological status was assessed with the American Spinal Injury Association (ASIA) scale. Clinical infection index including the C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) was also reviewed. Moreover, fusion and changes of sagittal alignment were investigated radiologically. There was a significantly longer operative time, hospital stay and greater blood loss in group A. The VAS scores improved significantly at each follow-up interval and post-operative VAS score was significantly lower in group B. At the last follow-up, ESR and CRP returned to normal for all patients. There was at least one grade level improvement in ASIA score. No statistical difference in corrected rate, loss of sagittal angle and lumbar lordosis was found between the two groups. There was no significant difference in fusion rate, mean fusion time and complications between the two groups. Compared with iliac bone graft, the autogenous spinous process bone graft can be less invasive and painful for the single segment lumbar PS. One-stage posterior debridement, autogenous spinous process bone graft and instrumentation can provide satisfactory results for appropriate cases.