Minimally invasive spine surgery in the treatment of pyogenic spondylodiscitis: an initial retrospective series study

Posterior fixation without debridement for pyogenic spondylodiscitis can promote infection control: initial evaluation of a pyogenic spondylodiscitis posterior fixation rat model

PURPOSE

Pyogenic spondylodiscitis is a significant health concern, particularly in older individuals. Minimally invasive surgical techniques, such as posterior fixation, are promising for infection control; however, their mechanisms remain unclear. This study aimed to clarify how posterior fixation promotes infection control in an animal model.

METHODS

Thirty female Wistar rats were used to create a pyogenic spondylodiscitis model by injecting methicillin-sensitive Staphylococcus aureus into the intervertebral space between the 6th and 7th coccygeal vertebrae. Three days post-injection, rats were divided into fixation and control groups. The fixation group underwent posterior fixation with an external fixator, whereas the control group underwent screw insertion alone. Bone destruction was assessed via microcomputed tomography on postoperative days (POD) 7, 14, and 21. Immunohistochemistry for cathepsin K and receptor activator of nuclear factor-kappa B ligand (RANKL) was performed on POD 7 samples to assess osteoclast activity.

RESULTS

The fixation group showed less bone destruction than the control group at POD 14 (35% vs. 56%, p = 0.0007) and POD 21 (30% vs. 52%, p < 0.0001). The cathepsin K-positive area was significantly reduced in the fixation group (p = 0.027). RANKL expression was localized within the intervertebral disc in the fixation group, whereas RANKL was strongly expressed on the bone surface adjacent to the disc in control. The RANKL-positive area was also reduced in the fixation group (p = 0.041).

CONCLUSIONS

Our combined model of pyogenic spondylodiscitis and posterior fixation supports the theory that posterior fixation stability suppresses RANKL and osteoclast expression, promoting infection control.

Unique characteristics of bone union at the infected vertebrae after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis: a retrospective multicenter cohort study

BACKGROUND

The current study aimed to evaluate the bone union rate between infected vertebrae after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis.

METHODS

This retrospective multicenter cohort study evaluated 75 patients of posterior fixation for thoracolumbar pyogenic spondylitis that have been recorded at six relevant institutions from January 2016 to December 2022. Data on age, sex, location of infected vertebrae, number of infected disks, comorbidity, Pola classification, number of vertebrae fixed according to surgery, implant failure requiring revision surgery, and distance according to the type of infected vertebrae after surgery were evaluated. Further, their association with postoperative bone union was investigated > 12 months postoperatively.

RESULTS

Finally, 40 patients were included in the study. In total, 32 (80%) patients achieved bone union at the infected vertebrae after minimally invasive posterior fixation without bone grafting. The mean duration from surgery to union was 10.7 months. Twenty-six (65%) patients initially achieved bone union at the lateral and/or anterior bridging callus. Patients with multiple-level infected disks (33%, 2/6 patients) had a lower bone union rate than those with a single-level infected disk (88%, 30/34 patients) (p = 0.0095).

CONCLUSIONS

In 80% of patients, bone union at the infected vertebrae was achieved after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis. A total of 65% of the patients achieved initial bone union at the lateral and/or anterior bridging callus. Moreover, patients with multiple-level infected disks had a low bone union rate. Hence, the treatment strategy should be cautiously considered.

TRIAL REGISTRATION

This study was registered retrospectively and all procedures used in this study including the review of patient records were approved by the institutional review board.

Retroperitoneal Continuous Local Antibiotic Perfusion for Refractory Pyogenic Vertebral Osteomyelitis: A Case Report

Pyogenic vertebral osteomyelitis (PVO) is a prevalent infection in the elderly, frequently complicated by iliopsoas and epidural abscesses. Traditional treatments are often ineffective for refractory cases. In this report, a 76-year-old man with PVO, iliopsoas, and epidural abscess was unresponsive to antibiotics, presenting with severe lower back pain and functional impairments. A two-stage surgical intervention was implemented: anterior debridement, autogenous bone graft fixation, and novel application of retroperitoneal continuous local antibiotic perfusion (CLAP), followed by posterior fixation. A contrast test verified correct CLAP perfusion into the iliopsoas abscess and intervertebral disc space. Substantial improvements were noted postoperatively, including a marked reduction in pain, inflammation, and the size of both abscesses. In conclusion, this case demonstrates the feasibility and effectiveness of retroperitoneal CLAP in treating refractory PVO, offering a potential innovative solution for cases resistant to conventional therapies.

A modified minimally invasive surgery for thoracic pyogenic spondylitis: Percutaneous pedicle screw fixation in combination with a vertebral debridement in a separate posterolateral approach-A case report

In this report, we present a successfully treated case of intractable thoracic pyogenic spondylitis using one-step curettage/bone grafting of spinal anterior segment and less-contaminated percutaneous spinal posterior fixation via separated posterior approaches, which was not compatible with conventional spinal instruments.

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.

The Limitation of Endoscopic Surgery Using the Full Endoscopic Discectomy System for the Treatment of Destructive Stage Pyogenic Spondylodiscitis: A Case Series

Introduction

Conservative therapy, including appropriate antibiotics and bracing, is usually adequate for most patients with pyogenic spondylodiscitis. If conservative treatment fails, surgical intervention is needed. However, major spinal surgery comprising anterior debridement and accompanying bone grafting with or without additional instrumentation is often related to undesired postoperative complications. In recent years, with minimally invasive surgery, the diagnostic and therapeutic value of endoscopic lavage and drainage has been proven. This study reports a case series of patients who required open revision surgery after treatment with endoscopic surgery using the full endoscopic discectomy system (FED), indicating the surgical limitations of endoscopic surgery for pyogenic spondylodiscitis.

Methods

We retrospectively investigated the medical records of 4 patients who underwent open debridement and anterior reconstruction with posterior instrumentation following endoscopic surgery for their advanced lumbar infectious spondylitis. They had been receiving conservative treatment with antibiotics for 12–15 days. They also had various comorbidities, including kidney disease, heart failure, and diabetes. Numerical rating scale pain response, perioperative imaging studies, and C-reactive protein (CRP) levels were determined, and causative bacteria were identified. Primarily, the bone destruction stage was classified using computed tomography with reference to Griffiths' scheme.

Results

All patients had severe back pain before surgery with no relief of the pain after FED. Increased pain, including radicular pain after FED, was noted in one case. Causative pathogens from biopsy specimens were identified in 3 (75%) of the 4 cases. In preoperative radiological evaluation, all cases were classified as destructive stage in Griffiths' scheme. The CRP levels of all the patients decreased slightly after endoscopic surgery. Relapse of spinal infection after revision surgery was not noted in any patient during the follow-up period.

Conclusion

The surgical treatment of destructive-stage spondylitis with FED alone can increase low back pain due to aggressive debridement.