Safety and efficacy of polyetheretherketone (PEEK) cages in combination with posterior pedicel screw fixation in pyogenic spinal infection

Uniportal endoscopic decompression and debridement for infectious diseases of spine with neurological deficits: a retrospective study in China

STUDY DESIGN

A retrospective study.

PURPOSE

To evaluate the clinical efficacy of uniportal endoscopic decompression and debridement (UEDD) in treating infectious diseases of the spine (IDS) with neurological deficits.

OVERVIEW OF LITERATURE

IDS patients with neurological deficits often require urgent surgical decompression. However, the efficacy of UEDD in this complex patient population is not well-characterized.

METHODS

This retrospective study analyzed 32 consecutive IDS patients who underwent UEDD surgery. Clinical features, laboratory data (erythrocyte sedimentation rate and C-reactive protein), and treatment outcomes were analyzed.

RESULTS

Definite microorganisms were identified in 27 patients (84.3%), with 24 (88.9%) meeting cure criteria. The cure rate was significantly higher in the detected pathogen group compared to the undetected pathogen group (88.9% vs. 80%; χ²=19.36, p<0.0001). Metagenomic next generation sequencing (mNGS) provided faster diagnosis (41.72±6.81 hours) compared to tissue culture (95.74±35.47 hours, p<0.05). The predominant causative pathogen was Mycobacterium tuberculosis, followed by Staphylococcus aureus. Significant improvements were observed in Visual Analog Scale pain scores, from a mean of 7.9 preoperatively to 1.06 at 1 year postoperatively. The Oswestry Disability Index revealed a similar trend, showing significant improvement (p<0.05).

CONCLUSIONS

UEDD is a viable alternative to traditional open surgery for managing IDS in high-risk patients. UEDD offers a dual therapeutic-diagnostic advantage during the initial admission phase, enabling simultaneous debridement, neurological decompression, and targeted biopsy in a single intervention. Compared with traditional tissue culture, mNGS enables rapid microbiological diagnosis and extensive pathogen coverage.

Influence of instrumentation type on outcomes after surgical management of spondylodiscitis: a systematic review and meta-analysis

OBJECTIVE

Spondylodiscitis refers to infection of the intervertebral disk and neighboring structures. Outcomes based on instrumentation type are not well reported in the literature, but are important in establishing guidelines for surgical management of spondylodiscitis. This study aims to clarify the effect of instrumentation material selection on clinical and radiographic outcomes in patients with spondylodiscitis.

METHODS

Studies that evaluated the use of polyetheretherketone (PEEK), titanium, allograft, and/or autologous bone grafts for spondylodiscitis were identified in the literature. Radiographic and clinical data were analyzed using a meta-analysis of proportions, with estimated risk and confidence intervals reported for our primary study outcomes.

RESULTS

Thirty-two retrospective studies totaling 1088 patients undergoing surgical management of spondylodiscitis with PEEK, TTN, allograft, and autologous bone graft instrumentation were included. There were no differences in fusion rates (p-interaction = 0.55) with rates of fusion of 93.4% with TTN, 98.6% with allograft, 84.2% with autologous bone graft, and 93.9% with PEEK. There were no differences in screw loosening (p-interaction = 0.52) with rates of 0.33% with TTN, 0% with allograft, 1.3% with autologous bone graft, and 8.2% with PEEK. There were no differences in reoperation (p-interaction = 0.59) with rates of 2.64% with TTN, 0% with allograft, 1.69% with autologous bone graft, and 3.3% with PEEK.

CONCLUSIONS

This meta-analysis demonstrates that the choice of instrumentation type in the surgical management of spondylodiscitis resulted in no significant differences in rate of radiographic fusion, screw loosening, or reoperation. Future comparative studies to optimize guidelines for the management of spondylodiscitis are needed.

Clinical and surgical outcome in patients with cervical spondylodiscitis-a single-center retrospective case series of 24 patients

OBJECTIVE

Cervical spondylodiscitis is a rare pathology, with an incidence of 0.5-2.5 per 100,000 population, posing significant potential risks. This type of infection can lead to neurological impairment in up to 29% of patients. Radical surgical debridement of the infected segment, fusion, and an intravenous antibiotic regimen remains the gold standard in most spine centers. This study aimed to analyze the surgical outcome in a tertiary spine center based on disease severity.

METHODS

In this study, we retrospectively included all patients diagnosed with cervical spondylodiscitis and treated at the University Hospital Augsburg between January 2017 and May 2022. We collected and analyzed baseline parameters on clinical presentation with symptoms, laboratory parameters, radiological appearance, and surgical parameters such as type of approach and implant, as well as neurological and radiological outcomes. Descriptive statistics were performed using SPSS, and relevant correlations were examined using the t-test for independent samples and the chi-square test.

RESULTS

Twenty-four patients (9%) with cervical spondylodiscitis were identified. Twenty-two (92%) surgically treated patients were subdivided into the complicated discitis group (n = 14, 64%) and the uncomplicated discitis group (n = 8, 36%). Seventeen patients (71%) presented with sepsis on admission, 17 patients (71%) were diagnosed with epidural abscess on primary imaging, and 5 patients (21%) had more than one discitis lesion at a distant spinal segment. The presence of epidural abscess was significantly associated with systemic sepsis (OR = 6.2; p = 0.03) and myelopathy symptoms (OR = 14.4; p = 0.00). The most frequently detected specimen was a multisensitive Staphylococcus aureus (10 patients, 42%). Six patients (25%) died after a median of 20 days despite antibiogram-accurate therapy, five of whom were diagnosed with a complicated type of discitis. The follow-up data of 15 patients (63%) revealed permanent neurological damage in 9 patients (38%). Notably, the surgical approach was a significant factor for revision surgery (p = 0.008), as three out of five (60%) ventrodorsal cases with complicated discitis were revised.

CONCLUSION

Cervical spondylodiscitis represents a severe infectious disease that is often associated with permanent neurological damage or a fatal outcome, despite adequate surgical and antibiotic treatments. Complicated types of discitis may require a more challenging surgical and clinical course.

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.

The Incidence, Changes and Treatments of Cervical Deformity After Infection and Inflammation

A healthy cervical spine with normal movement is the basis of many daily activities and is essential for maintaining a good quality of life. However, the alignment, fusion, and structure of the cervical spine can change for various reasons, leading to cervical deformity, mainly kyphosis. Approximately 5%‒20% of spinal infections in the cervical spine cause cervical deformity. The deformity can recover early; however, the disease's long-term existence or the continuous action of abnormal stress may lead to intervertebral fusion and abnormal osteophytes. Many gaps and controversies exist regarding infectious cervical deformities, including a lack of clear definitions and an acceptable classification system thereby requiring further research. Moreover, there is no consensus on the indications for postinfectious cervical deformity associated with <i>Mycobacterium tuberculosis</i>, <i>Staphylococcus aureus</i>, and Brucellosis. Therefore, we reviewed and discussed the incidence, clinical manifestations, changes, and treatment of infectious and inflammatory secondary cervical deformities from common to rare to provide a theoretical basis for clinical decision-making.

The one-stop-shop approach: Navigating lumbar 360-degree instrumentation in a single position

Objective

Treatment strategies of patients suffering from pyogenic spondylodiscitis are a controverse topic. Percutaneous dorsal instrumentation followed by surgical debridement and fusion of the infectious vertebral disc spaces is a common approach for surgical treatment. Technical advances enable spinal navigation for dorsal and lateral instrumentation. This report investigates combined navigated dorsal and lateral instrumentation in a single surgery and positioning for lumbar spondylodiscitis in a pilot series.

Methods

Patients diagnosed with 1- or 2-level discitis were prospectively enrolled. To enable posterior navigated pedicle screw placement and lateral interbody fusion (LLIF) patients were positioned semi-prone in 45-degree fashion. For spinal referencing, a registration array was attached to the pelvic or spinal process. 3D scans were acquired intraoperatively for registration and implant control.

Results

27 patients suffering from 1- or 2-level spondylodiscitis with a median ASA of 3 (1–4) and a mean BMI of 27.9 ± 4.9 kg/m2 were included. Mean duration of surgery was 146 ± 49 min. Mean blood loss was 367 ± 307 ml. A median of 4 (4–8) pedicle screws were placed for dorsal percutaneous instrumentation with an intraoperative revision rate of 4.0%. LLIF was performed on 31 levels with an intraoperative cage revision rate of 9.7%.

Conclusions

Navigated lumbar dorsal and lateral instrumentation in a single operation and positioning is feasible and safe. It enables rapid 360-degree instrumentation in these critically ill patients and potentially reduces overall intraoperative radiation exposure for patient and staff. Compared to purely dorsal approaches it allows for optimal discectomy and fusion while overall incisions and wound size are minimized. Compared to prone LLIF procedures, semi-prone in 45-degree positioning allows for a steep learning curve due to minor changes of familiar anatomy.

The Role of Diskectomy in Reducing Infectious Complications after Surgery for Lumbar Spondylodiscitis

BACKGROUND

 Surgery for pyogenic Spondylodiscitis as an adjunct to antibiotic therapy is an established treatment. However, the technique and extent of surgical debridement remains a matter of debate. Some propagate diskectomy in all cases. Others maintain that stand-alone instrumentation is sufficient.

METHODS

 We reviewed charts of patients who underwent instrumentation for pyogenic Spondylodiscitis with a minimum follow-up of 1 year. Patients were stratified according to whether they underwent diskectomy plus instrumentation or posterior instrumentation alone. Outcome measures included the need for surgical revision due to recurrent epidural intraspinal infection, wound revision, and construct failure.

RESULTS

 In all, 257 patients who underwent surgery for pyogenic Spondylodiscitis were identified. Diskectomy and interbody procedure (group A) was performed in 102 patients, while 155 patients underwent instrumentation surgery for Spondylodiscitis without intradiskal debridement (group B). The mean age was 67 ± 12 years, and 102 patients (39.7%) were females. No significant differences were found in the need for epidural abscess recurrence therapy (group A [2.0%] and 5 cases in group B [3%; p = 0.83]) and construct failure (p = 0.575). The need for wound revisions showed a tendency toward higher rates in the posterior instrumentation-only group, which failed to reach significance (p = 0.078).

CONCLUSIONS

 Overall, intraspinal relapse of surgically treated pyogenic diskitis was low in our retrospective series. The choice of surgical technique was not associated with a significant difference. However, a somewhat higher rate of wound infections requiring revision in the group where no diskectomy was performed has to be weighed against a longer duration of surgery in an already ill patient population.

Surgical Treatment Strategies for Pyogenic Spondylodiscitis of the Thoracolumbar Spine

BACKGROUND

Despite advances, the morbidity and mortality rates of patients with spondylodiscitis remains high, with an increasing incidence worldwide. Although conservative therapy has progressed, several cases require surgical intervention. However, the indication and opportunities for surgical treatment are still disputable.

METHODS

In a joint consensus, the members of the 'Spondylodiscitis' working group of the Spine Section of the German Society for Orthopaedics and Trauma Surgery considered current literature, particularly the newly published S2k guideline of the AWMF, and examined the surgical indications and treatment strategies for thoracolumbar spondylodiscitis.

RESULTS

Surgical intervention for spondylodiscitis is only required in a small percentage of patients. In studies comparing conservative and surgical therapies, most patients benefitted from surgery, regardless of the surgical technique selected. Presently, the standard procedure is a combined dorsoventral approach, in which a monolateral attempt should always be made. The choice of material (PEEK, titanium) for ventral support does not influence the clinical result.

Biodegradable interbody cages for lumbar spine fusion: Current concepts and future directions

Lumbar fusion often remains the last treatment option for various acute and chronic spinal conditions, including infectious and degenerative diseases. Placement of a cage in the intervertebral space has become a routine clinical treatment for spinal fusion surgery to provide sufficient biomechanical stability, which is required to achieve bony ingrowth of the implant. Routinely used cages for clinical application are made of titanium (Ti) or polyetheretherketone (PEEK). Ti has been used since the 1980s; however, its shortcomings, such as impaired radiographical opacity and higher elastic modulus compared to bone, have led to the development of PEEK cages, which are associated with reduced stress shielding as well as no radiographical artefacts. Since PEEK is bioinert, its osteointegration capacity is limited, which in turn enhances fibrotic tissue formation and peri-implant infections. To address shortcomings of both of these biomaterials, interdisciplinary teams have developed biodegradable cages. Rooted in promising preclinical large animal studies, a hollow cylindrical cage (Hydrosorb™) made of 70:30 poly-l-lactide-co-d, l-lactide acid (PLDLLA) was clinically studied. However, reduced bony integration and unfavourable long-term clinical outcomes prohibited its routine clinical application. More recently, scaffold-guided bone regeneration (SGBR) with application of highly porous biodegradable constructs is emerging. Advancements in additive manufacturing technology now allow the cage designs that match requirements, such as stiffness of surrounding tissues, while providing long-term biomechanical stability. A favourable clinical outcome has been observed in the treatment of various bone defects, particularly for 3D-printed composite scaffolds made of medical-grade polycaprolactone (mPCL) in combination with a ceramic filler material. Therefore, advanced cage design made of mPCL and ceramic may also carry initial high spinal forces up to the time of bony fusion and subsequently resorb without clinical side effects. Furthermore, surface modification of implants is an effective approach to simultaneously reduce microbial infection and improve tissue integration. We present a design concept for a scaffold surface which result in osteoconductive and antimicrobial properties that have the potential to achieve higher rates of fusion and less clinical complications. In this review, we explore the preclinical and clinical studies which used bioresorbable cages. Furthermore, we critically discuss the need for a cutting-edge research program that includes comprehensive preclinical in vitro and in vivo studies to enable successful translation from bench to bedside. We develop such a conceptual framework by examining the state-of-the-art literature and posing the questions that will guide this field in the coming years.

Endoscopic treatment of spondylodiscitis: systematic review

BACKGROUND

Spondylodiscitis is a severe condition where standalone antibiotic therapy resolves most cases. In refractory infections, open surgery may aid with infection debulking. However, significant morbidity can occur. Nowadays, endoscopic approaches are emerging as an alternative. However, until now, only small-scale studies exist. Being so, we carried the first systematic review on spondylodiscitis endoscopic debridement indications, technique details, and outcomes.

METHODS

Search for all English written original studies approaching the spondylodiscitis endoscopic treatment was performed using PubMed and EBSCO host. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and a pre-specified protocol was registered at PROSPERO (CRD42020183657).

RESULTS

Fourteen studies involving 342 participants were included for analysis. Data overall quality was fair. Indications for the endoscopic approach were poorly defined. The most consensual indication was refractory infection to conservative treatment. Spinal instability or neurological deficits were common exclusion criteria. All authors described similar techniques, and despite the frequent severe co-morbidities, procedure morbidity was low. Re-interventions were common. Microorganism identification varied from 54.2 to 90.4%. Treatment failure among studies ranged from 0 to 33%. Pain, functional status, and neurological deficits had satisfactory improvement after procedures.

CONCLUSIONS

The endoscopic debridement of spondylodiscitis seems to be an effective and safe approach for refractory spondylodiscitis. A novel approach with initial endoscopic infection debulking and antibiotic therapy could improve the success of spondylodiscitis treatment.

Three-Staged Surgical Strategy as a Combined Approach for Multilevel Cervical Pyogenic Spondylodiscitis

Cervical pyogenic spondylodiscitis is rare but can lead to severe clinical problems that often require aggressive surgical treatment for neurological deterioration and life-threatening conditions. Although combined surgical procedures are often utilized to treat multilevel cervical regions, there is a clinical debate regarding the appropriate order and timing of surgeries using the anterior and posterior approaches. Here, we report a case of severe multilevel cervical pyogenic spondylodiscitis treated using a three-staged surgical strategy consisting of cervical laminectomy, posterior fixation, and anterior corpectomy and fusion with an autologous long bone graft; the outcome was quite favorable. Our report demonstrates the safety and usefulness of three-staged surgery in the multilevel cervical region, especially under urgent situations.

PEEK vs Titanium Cage for Anterior Column Reconstruction in Active Spinal Tuberculosis: A Comparative Study

Background

Posterolateral decompression and debridement in patients with TB spine led to defect in the anterior column which makes the spinal column unstable, thus making anterior column reconstruction an important step in surgical management.

Objective

Through the study, authors sought to answer the following questions: 1) What are the differences in clinical outcomes between patients with TB spine undergoing anterior column reconstruction using titanium mesh cage versus PEEK cage? 2) What are the differences in radiological outcomes between these two groups of patients?

Methods

This is a retrospective comparative study including patients with TB spine undergoing surgical management. The included subjects were divided into groups A and B depending on the implantation of PEEK or titanium mesh cage respectively for anterior column reconstruction. Outcome criteria analyzed included clinical criteria like VAS and ODI scores, radiological criteria like kyphosis correction, loss of kyphosis at follow-up, cage subsidence, and bony fusion on a 2D CT scan.

Results

The study population included 14 patients in Group A and 15 patients in Group B. Improvement in VAS and ODI scores was comparable between groups. There was no significant difference in radiological outcome measures between the two groups, however, two patients from group B showed implant-related complications needing revision. All patients showed good bony fusion at the final follow-up.

Conclusion

PEEK and titanium cages have comparable clinico-radiological outcomes for anterior column reconstruction in patients with active TB spine. Its advantages for being radiolucent and its ease of use may make it a choice of implant.

The Surgical Treatment of Pyogenic Spondylodiscitis using Carbon-Fiber-Reinforced Polyether Ether Ketone Implants: Personal Experience of a Series of 81 Consecutive Patients

BACKGROUND

Pyogenic spondylodiscitis (PSD) is a complex disorder that often required postoperative imaging. Carbon-fiber-reinforced polyether ether ketone (CFRP) is radiolucent and offers an optimal assessability of anatomic structures.

METHODS

A retrospective file review of patients who were operated on for PSD using CFRP implants was performed to assess the clinical outcome, implant-associated complications, and revision surgery. A minimum follow-up of 3 months was required for evaluation of clinical and radiographic data, which included computed tomography and magnetic resonance imaging (MRI) assessment, to determine implant stability and assessability of soft tissue and nerve structures using a grading system.

RESULTS

Eighty-one consecutive patients with a mean of 69.5 years were identified. Debridement and stabilization were performed in 8 cervical, 17 thoracic, and 57 lumbar procedures; 72 interbody fusion procedures using cages were performed. Intraoperatively, no implant-associated complication was noted. The mean follow-up was 7 months, at which 52 patients attended. Improved mobility and reduced pain levels were reported by 87%, and MRI assessability was graded ideal. Residual sign of infection was seen in 5 cases, which influenced antibiotic therapy. Asymptomatic radiolucent zones were identified in 13 patients (16%) and screw loosening in 2 (2.4%). In 1 patient, the pedicle screw tip broke and remained within the vertebral body. A repeated procedure because of progressive vertebral body destruction, implant loosening, or subsidence was performed in 5 patients (6.1%).

CONCLUSIONS

The surgical treatment of PSD using CFRP is safe. The repeat procedure rate as a result of implant loosening is 6.1%. Minimal artifacts offer ideal assessability of soft tissue structures on an MRI.

Treatment of single-segment suppurative spondylitis with the transforaminal endoscopic focal cleaning and drainage

Objective: To evaluate the clinical value of the transforaminal endoscopic focal cleaning and drainage for suppurative spondylitis.Design: Retrospective study.Participants: Twenty-one patients with single-segment suppurative spondylitis.Interventions: All patients were treated with the transforaminal endoscopic focal cleaning and drainage.Outcome Measures: The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were measured before and after the operation. Visual analogue scale (VAS) was used to evaluate the relief of pain symptoms. Neurological function American Spinal Injury Association (ASIA) grade was used to evaluate the recovery of neurological function. The postoperative clinical efficacy of the patients was evaluated using the Kirkaldy-Willis functional scoring criteria. The stability of the spine and the recurrence of infection were evaluated by imaging data.Results: Postoperative bacteriological culture results showed positive in 15 cases and no bacteria growth in 6 cases. Besides, 16 cases were pathologically diagnosed. The ESR, CRP, and VAS scores at 2 weeks postoperatively and at the last follow-up were significantly improved compared with those at pre-operation. At the last follow-up, the clinical outcome was excellent in 17 cases, good in 3 cases, and fair in 1 case, according to the Kirkaldy-Willis functional scoring criteria; and the ASIA grade returned to normal. There was no significant difference in the Cobb angle between the last follow-up and the pre-operation. There was no recurrence of infection during the follow-up period.Conclusion: The transforaminal endoscopic focal cleaning and drainage is a minimally invasive, effective and safe surgical procedure for suppurative spondylitis.

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.

Bacterial adhesion characteristics on implant materials for intervertebral cages: titanium or PEEK for spinal infections?

PURPOSE

Surgical intervention with intercorporal stabilisation in spinal infections is increasingly needed. Our aim was to compare titanium and polyetheretherketon (PEEK) cages according to their adhesion characteristics of different bacteria species in vitro.

METHODS

Plates made from PEEK, polished titanium (Ti), two-surface-titanium (TiMe) (n = 2-3) and original PEEK and porous trabecular structured titanium (TiLi) interbody cages (n = 4) were inoculated in different bacterial solutions, S.aureus (MSSA, MRSA), S.epidermidis and E.coli. Growth characteristics were analysed. Biofilms and bacteria were visualised using confocal- and electron microscopy.

RESULTS

Quantitative adherence of MSSA, MRSA, S.epidermidis and E.coli to Ti, TiMe and PEEK plates were different, with polished titanium being mainly advantageous over PEEK and TiMe with significantly less counts of colony forming units (CFU) for MRSA after 56 h compared to TiMe and at 72 h compared to PEEK (p = 0.04 and p = 0.005). For MSSA, more adherent bacteria were detected on PEEK than on TiMe at 32 h (p = 0.02). For PEEK and TiLi cages, significant differences were found after 8 and 72 h for S.epidermidis (p = 0.02 and p = 0.008) and after 72 h for MSSA (p = 0.002) with higher bacterial counts on PEEK, whereas E.coli showed more CFU on TiLi than PEEK (p = 0.05). Electron microscopy demonstrated enhanced adhesion in transition areas.

CONCLUSION

For S.epidermidis, MSSA and MRSA PEEK cages showed a higher adherence in terms of CFU count, whereas for E.coli PEEK seemed to be advantageous. Electron microscopic visualisation shows that bacteria did not adhere at the titanium mesh structure, but at the border zones of polished material to rougher parts.

Surgical revision strategies for postoperative spinal implant infections (PSII)

Over the last years the number of spine surgeries with instrumentation has grown to an indispensable column in the treatment for different pathologies of the spine. A further increase in the incidence of instrumented spinal surgery is expected throughout the next years. Although the implementation and development of new techniques offer faster and more minimal invasive procedures, shortening surgery time, reducing soft tissue injury and revision due to hardware misplacement, the incidence of postoperative spinal implant infections (PSII) remains high. PSII related complications and revision procedures pose an enormous socioeconomic burden. Therefore, standardized strategies and protocols for treatment of PSII are urgently needed. While in former times hardware exchange or hardware removal was common practise in the field of spine surgery this approach has changed over the last years. Although the evidence from clinical studies in the field of PSII is of limited evidence, critical variables for revision strategies of PSII have been identified. Further, to quickly advance in the field of PSII it is certainly important to extrapolate and learn using data regarding the management from other fields of prosthetic joint infections. This should include clinical as well as experimental work in particular in the context of the biofilm, sonication as well as microbiological concepts. Over the last years, at our institution standardized procedures for diagnostic, surgical as well as antimicrobial treatment have been developed, based on the latest recommendations in peer-reviewed literature and our own data. Here we give an overview about surgical revision strategies for PSII and discuss the key points of our standardized protocol.

Safety and efficacy of polyetheretherketone (PEEK) cages in combination with one-stage posterior debridement and instrumentation in Lumbar Brucella Spondylitis

OBJECTIVE

The aim of this study was to explore the efficacy and safety of surgical treatment of lumbar brucella spondylitis with PEEK cages combined with one-stage posterior debridement and instrumentation.

METHODS

We performed a retrospective study for adult patients with lumbar brucella spondylitis. Medical records, imaging studies and laboratory data were collected, back pain was measured by employing the visual analog scale (VAS) and the neurological status was evaluated by using the American Spinal Injury Association (ASIA) scale.

RESULTS

A total of 61 consecutive patients (42 males and 19 females) were enrolled with the mean age at presentation of 56.33 ± 9.16 years old. L3-4 and L4-5 were the most infected levels with the ratios of 21.31 % and 19.67 % respectively. Moreover, 12 (19.67 %) patients suffered multiple-level infection and 5 (5/12, 41.67 %) of them had non-contiguous spondylitis. In addition, epidural masses were found in 26 (42.62 %) cases and psoas abscesses were found in 14 (22.95 %) cases. The number of operative segment depended on operation indications (failure of conservative measures, instability, kyphosis, intractable pain and/or neurological impairment). VAS scores were significantly improved at 6-weeks and the last follow-up. Among the 23 (37.70 %) patients with neurological deficits, 19 (19/23, 82.61 %) obtained a full recovery and 4 (4/23, 17.39 %) had been improved incompletely during the last follow-up. All patients exhibited satisfactory bone fusion during the last follow-up. Local infection of surgical site was identified in 6 (9.84 %) cases and no other surgery-related complications were found.

CONCLUSION

Use of PEEK cages for interbody fusion is feasible and safe in patients suffering from lumbar brucella spondylitis.

Cervical Epidural Abscess due to Brucella Treated with Decompression and Instrumentation: A Case Report and Review of Literature

Brucella is caused by a Gram-negative bacillus and is a common disease in endemic areas where people are in close contact with animals and dairy products, but brucellar cervical epidural abscess is rare. We describe a rare case of a C5–6 brucellar epidural abscess in a veterinary doctor who was treated with decompression and instrumentation. We also review the cases of cervical brucellar epidural abscess treated with instrumentation in the literature.

Consensus on Implants in Infections After Spine Surgery

In July of 2018, the Second International Consensus Meeting (ICM) on Musculoskeletal Infection convened in Philadelphia, PA was held to discuss issues regarding infection in orthopedic patients and to provide consensus recommendations on these issues to practicing orthopedic surgeons. During this meeting, attending delegates divided into subspecialty groups to discuss topics specifics to their respective fields, which included the spine. At the spine subspecialty group meeting, delegates discussed and voted upon the recommendations for 63 questions regarding the prevention, diagnosis, and treatment of infection in spinal surgery. Of the 63 questions, 9 focused on implants questions in spine surgery, for which this article provides the recommendations, voting results, and rationales.

Application of polyetheretherketone cages through minimally invasive oblique retroperitoneal approach for the treatment of lumbar polymicrobial spondylodiscitis: A STROBE-compliant retrospective study with 7 cases

Despite the plethora of evidence in support of the use of structural osseous autograft in lumbar spondylodiscitis, attention has recently been turned to the addition of synthetic materials such as polyetheretherketone (PEEK) to restore anterior vertebral column support.From January 2015 to April 2017, 7 patients with lumbar polymicrobial spondylodiscitis were surgically treated with a minimally invasive oblique retroperitoneal approach to the infected focus. The patients underwent a standard lateral minimally invasive oblique retroperitoneal approach using direct lateral interbody fusion system. The PEEK cages were loaded with autologous bone graft. All the patients underwent posterior fixation with percutaneous pedicle screw instrumentation. Lumbar function was measured using Oswestry Disability Index, and pain was measured with visual analog scale. Fusion and subsidence were also recorded.The study included 5 female and 2 male patients. The median age was 58.9 years. The duration of follow-up was 31.8 ± 6.1 months (range: 24-47). All patients recovered from the infection without relapse within 24-month follow-up. Visual analog scale significantly declined from 7.57 ± 0.53 before surgery to 1.57 ± 0.53 at 12-month follow-up. Mean Oswestry Disability Index decreased from 72.14 ± 6.82 before surgery to 22.28 ± 2.13 after surgery. All patients had solid fusion at 2-year follow-up. Fusion occurred at 6 to 15 months (mean 9.8 months).The specific use of PEEK cages in lumbar polymicrobial spondylodiscitis suggests reliable outcome in terms of clinical and imaging outcomes in our limited cases.

Treatment considerations for cervical and cervicothoracic spondylodiscitis associated with esophageal fistula due to cancer history or accidental injury: a 9-patient case series

BACKGROUND

The combination of cervical spondylodiscitis and esophageal fistula is rare but life-threatening. Due to both the rarity of these conditions' coincidence and the complexity and heterogeneity of individual cases, there is no optimal treatment or management approach. The aims of this study are to obtain an overview of patients' outcomes and to discuss treatment options.

METHOD

This study is a retrospective analysis of patients who presented with cervical spondylodiscitis and associated esophageal fistula between January 2010 and November 2018. We examined reports of 59 patients who suffered from cervical spondylodiscitis and included nine patients (15.25%) who had an esophageal fistula as the underlying cause. We assessed clinical findings, treatment, and outcome.

RESULTS

Three of the nine patients were female, and the mean age of the sample was 64.56 years. Six of the patients had a history of esophagopharyngeal cancer and had undergone tumor resection followed by radiotherapy. Two of the remaining patients' fistulas were caused by an iatrogenic injury during cervical spine surgery and a swallowed toothpick; in the final case, the origin remained unclear. Five patients presented with tetraparesis or tetraplegia, and the other four patients were neurologically intact. In seven cases, dorsal instrumentation was initially performed. Three patients secondarily received a ventral approach for debridement, and one received explantation of the ventral implants. Two patients died during the hospital stay, and three were transferred to a palliative care unit. Thus, the spondylodiscitis and esophageal fistula were cured in only four patients. At discharge, two patients were neurologically intact, two others remained in tetraparesis.

CONCLUSIONS

Cervical spondylodiscitis in association with an esophageal fistula carries high morbidity and high mortality. Because patients whose infections are not cured have high morbidity, we recommend using interdisciplinary and individual management, including definite surgical treatment of the discitis and fistula, in every case.

Transforaminal Lumbar Interbody Fusion with Antibiotics Delivered by CaSO4 Drug Carrier System for Pyogenic Spondylodiscitis

BACKGROUND

Spondylodiscitis is a challenging spinal disorder that requires surgical treatment only as a last resort. The use of various procedures and instruments remains controversial. In this retrospective study, we reported the safety and efficacy of a CaSO₄ drug carrier system for the transforaminal lumbar interbody fusion (TLIF) procedure for lumbar pyogenic spondylodiscitis.

METHODS

Thirty-four patients with lumbar spondylodiscitis underwent TLIF. CaSO₄ beads carrying vancomycin and gentamycin were implanted in the trajectory of screws and disc spaces. We measured markers of inflammation, scores of neurologic recovery, and quality of life. The fusion status was assessed at final follow-up and the correction of local and total lordotic angle was calculated.

RESULTS

The patients were followed up for at least 12 months (range, 12-24 months). At 3 months follow-up, C-reactive protein levels and erythrocyte sedimentation rate returned to normal with no relapse. Nineteen patients with American Spinal Injury Association grade D preoperatively returned to American Spinal Injury Association grade E. The improvement on the visual analog scale and Oswestry Disability Index was 66.9% and 84.9%, respectively. At 12 months follow-up, 67.6% of patients achieved definitive union. The corrections of total and local lordotic angle were 10.02° ± 8.77° and 7.7° ± 8.75°, respectively. The rate of achievement of satisfactory Kirkaldy-Willis functional criteria was 85.3%.

CONCLUSIONS

The combined use of single-level TLIF with a CaSO₄ drug delivery system was safe and effective for treatment of pyogenic lumbar spondylodiscitis. The system promoted reduction of inflammation with limited fixed segments without a negative impact on fusion status. This procedure may be considered a novel choice for spondylodiscitis, with more efficacy and less invasion.

Management of Pyogenic Spinal Infection, review of literature

Objective

To evaluate the available evidence for the management of Pyogenic Spinal Infection (PSI).

Methods and results

A comprehensive search for the relevant literature published between 1990 and 2018 to evaluate the management of PSI was conducted.Nonoperative management of carefully selected patients for an adequate duration of antibiotics can result in satisfactory outcomes with low recurrence rate. When there is an indication for surgery, posterior approach, with or without debridement of infected tissue reported to be associated with good outcomes.

Conclusion

Studies with larger sample sizes and longer duration of follow up are recommended to formulate more comprehensive evidence.

Single-approach vertebral osteosynthesis in the treatment of spinal osteolysis by spondylodiscitis

OBJECTIVEBoth spontaneous and iatrogenic spondylodiscitis are becoming ever more frequent, yet there are no definite treatment guidelines. For many years the treatment protocol was conservative medical management or surgical debridement with patients immobilized or bedridden for weeks and often resulting in spinal deformity. The eventual development of spinal deformity can be difficult to treat. Over the last few years, the authors have preferred a single-approach instrumented arthrodesis when spondylolysis that evolves in deformity from somatic wedging occurs.METHODSThe authors retrospectively reviewed the clinical, radiological, and surgical records of 11 patients treated over the past 3 years for spondylodiscitis with osteosynthesis.RESULTSOverall, the authors treated 11 patients: 3 cases with tuberculous spondylodiscitis (1 dorsal, 2 lumbar); 6 cases with Staphylococcus aureus spondylodiscitis (1 cervical, 2 dorsal, 2 lumbar, 1 dorsolumbar); 1 spondylodiscitis with postsurgical lumbar deformity; and in 1 dorsolumbar case the germ was not identified. Surgical approaches were chosen according to spinal level: In 8 dorsolumbar cases a posterior osteosynthesis was achieved. In 1 cervical case an anterior approach was performed with autologous bone graft from iliac crest. In 2 thoracolumbar cases a posterolateral costotransversectomy was needed. In 1 lumbosacral case iliac somatic grafting was used. Ten patients received adequate antibiotic treatment with clinical remission, and 1 case is in initial follow-up. No complications due to instrumentation were recorded. Spinal deformity was prevented in 10 cases, whereas preexisting spinal deformity was partially corrected in 1 case. In all cases, arthrodesis achieved vertebral stability.CONCLUSIONSThis study has the limitations of a retrospective review with a limited number of patients. Instrumentation does not appear to hamper healing from infection. Moreover, spinal stabilization, which is assisted by the infectious process even in the absence of bone graft, allows early mobilization. Instrumented osteosynthesis should be preferred for spondylodiscitis with osteolysis and spinal instability because it allows early mobilization and rehabilitation whenever necessary. It prevents spinal deformity and does not hamper healing of infections.

Pyogenic Spondylodiscitis of the Thoracic Spine: Outcome of 1-Stage Posterior Versus 2-Stage Posterior and Anterior Spinal Reconstruction in Adults

OBJECTIVE

The aim of this study was to compare the clinical, radiologic, and functional outcomes of a 1-stage posterior treatment versus a 2-stage posterior-anterior treatment in patients with pyogenic thoracic spondylodiscitis.

METHODS

A 1-stage posterior debridement, stabilization, and fusion with titanium-coated polyetheretherketone (PEEK) or mesh cage through a dorsolateral approach was performed in group A. A 2-stage procedure with initial posterior stabilization and debridement and second-stage fusion with a PEEK cage or mesh cage was performed with an anterior approach in group B. Clinical outcomes included Oswestry Low Back Pain Disability Questionnaire and visual analog scale score. Radiologic outcomes included fusion rate and kyphotic angle correction. Secondary variables included pathogens, complications, blood loss, and operative time.

RESULTS

One-level spondylodiscitis was treated surgically in the thoracic spine of 47 patients: 25 patients in group A and 22 patients in group B. The most frequent segment was T12-L1 (27%). There was a significantly longer operative time and greater blood loss (P > 0.001) in group B. At last follow-up, sagittal profile reconstruction was significantly better (P > 0.05) in group B. Both groups showed similar radiologic results with fusion in 92% of cases. Improved clinical outcomes, pain, and quality of life were achieved in both groups with no significant differences between the 2 groups.

CONCLUSIONS

Better reconstruction of the sagittal profile was achieved in the posterior-anterior-treated group, but this did not affect the clinical outcome. No significant differences were found in the clinical and functional outcomes between the 2 groups. Posterior-anterior combined treatment should be considered in cases of large anterior defects if a posterior reconstruction is inadequate.

Considerations in computer-aided design for inlay cranioplasty: technical note

Context

Cranioplasty is a frequently performed procedure that uses a variety of reconstruction materials and techniques. In this technical note, we present refinements of computer-aided design–computer-aided manufacturing inlay cranioplasty.

Objective, design, and setting

In an attempt to decrease complications related to polyether-ether-ketone (PEEK) cranioplasty, we gradually made changes to implant design and cranioplasty techniques. These changes include under-contouring of the implant and the use of segmented plates for large defects, microplate fixation for small temporal defects, temporal shell implants to reconstruct the temporalis muscle, and perforations to facilitate the drainage of blood and cerebrospinal fluid and serve as fixation points.

Results

From June 2016 to June 2017, 18 patients underwent cranioplasty, and a total of 31 PEEK and titanium implants were inserted. All implants were successful.

Conclusions

These changes to implant design and cranioplasty techniques facilitate the insertion and fixation of patient-specific cranial implants and improve esthetic outcomes.

Spondylodiscitis revisited

Spondylodiscitis may involve the vertebral bodies, intervertebral discs, paravertebral structures and spinal canal, with potentially high morbidity and mortality rates.

A rise in the susceptible population and improved diagnosis have increased the reported incidence of the disease in recent years.

Blood cultures, appropriate imaging and biopsy are essential for diagnosis and treatment.

Most patients are successfully treated by conservative means; however, some patients may require surgical treatment.

Surgical indications include doubtful diagnosis, progressive neurological deficits, progressive spinal deformity, failure to respond to treatment, and unresolved pain.

Cite this article: EFORT Open Rev 2017;2:447–461. DOI: 10.1302/2058-5241.2.160062

Spontaneous Pyogenic Spondylodiscitis in the Thoracic or Lumbar Spine: A Retrospective Cohort Study Comparing the Safety and Efficacy of Minimally Invasive and Open Surgery Over a Nine-Year Period

PURPOSE

Pyogenic spondylodiscitis is a rare disease, but its incidence is increasing. Over the last decade, spinal surgery has been modified to become minimally invasive. In degenerative spinal disorders, such minimally invasive surgery (MIS) reduces blood loss, muscular trauma, and the hospital stay. However, it is not known whether MIS also confers these benefits to patients with pyogenic spondylodiscitis. This retrospective cohort study compared the safety and efficacy of MIS and the conventional open surgical procedure in patients with pyogenic spondylodiscitis.

METHODS

The study cohort consisted of all consecutive patients who underwent surgery for thoracic or lumbar pyogenic spondylodiscitis that was not caused by previous surgery or tuberculosis in our tertiary-care institution between January 2003 and December 2011.

RESULTS

Of the 148 eligible patients, 75 and 73 underwent MIS and open surgery, respectively. The 2 groups did not differ in terms of age, body mass index, American Society of Anaesthesiologists score, comorbidities, septic disease, or preoperative neurologic deficit. The 2 methods were associated with similar postoperative stays in the intensive care unit, overall hospital stays, complication rates, and postoperative survival. However, MIS was associated with a significantly shorter operating time, a lower perioperative need for blood products, and, as expected, an increased intraoperative fluoroscopy duration.

CONCLUSIONS

Our 9-year experience suggests that MIS is safe and effective for spontaneous pyogenic thoracic and lumbar spondylodiscitis.

First report on treating spontaneous infectious spondylodiscitis of lumbar spine with posterior debridement, posterior instrumentation and an injectable calcium sulfate/hydroxyapatite composite eluting gentamicin: a case report

Background

Spontaneous infectious spondylodiscitis is a rare, but serious disease with the risk of progressive neurological impairment. The surgical approach to spontaneous infectious spondylodiscitis is in most cases an anterior debridement and fusion, often in staged surgeries. Here we report a case of single-stage posterior debridement and posterior instrumented fusion in combination with an injectable calcium sulfate/hydroxyapatite composite eluting gentamicin.

Case presentation

A 59-year-old Caucasian man presented with a 6-week history of lumbar pain without sensory or motor disorders of his lower extremities. A magnetic resonance imaging scan of his lumbar spine in T2-weighted sequences showed a high signal of the intervertebral disc L4/L5 and in T1-weighted sequences an epidural abscess at the posterior wall of L4. Additional computed tomography imaging revealed osteolytic destruction of the base plate of L4 and the upper plate of L5. Antibiotic therapy was started with intravenous ciprofloxacin and clindamycin. We performed a posterior debridement via a minimally invasive approach, a posterior percutaneous stabilization using transpedicular screw-rod instrumentation and filled the intervertebral space with an injectable calcium sulfate/hydroxyapatite composite which elutes a high concentration of gentamicin. The patient’s lower back pain improved quickly after surgery and no recurrence of infection has been noticed during the 1-year follow-up. Computed tomography at 11 months shows complete bony fusion of L4 and L5.

Conclusions

An injectable calcium sulfate/hydroxyapatite composite releasing a high level of gentamicin can support the surgical treatment of spondylodiscitis in combination with posterior debridement and transpedicular screw-rod instrumentation.