This study included eight inpatients diagnosed with SIAVA in our hospital from January 2020 to May 2024. Mycobacterium tuberculosis was identified in three patients, and Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus constellatus, Peptostreptococcus micros, and Pseudomonas aeruginosa were each detected in one patient. The diagnosis of SIAVA relied on clinical manifestations, etiological evidence, and imaging findings, including low back pain, limited mobility, a history of PKP/PVP surgery, bone destruction and soft tissue abscess identified on computed tomography (CT)/magnetic resonance imaging (MRI), and pathogen detection.

We conducted this study in compliance with the principles of the Declaration of Helsinki. This study was approved by the Ethics Committee of the Second Affiliated Hospital of Chongqing Medical Universi (No., 2025-15; on March 18, 2025), and all patients provided informed consent for surgical treatment and signed relevant documents.

Demographic data, including age, gender, body mass index, Charlson comorbidity index (CCI), and comorbidities were collected from electronic medical records. Perioperative data included neurological deficits, VA segment and type, interval between initial surgery and readmission, pathogenic identification, type of etiological testing, interval between SIAVA diagnosis and revision surgery, segments and implants used in revision surgery, intraoperative complications, and outcomes at the last follow-up.

We measured the Visual Analog Scale (VAS) scores for back pain and the Oswestry Disability Index (ODI) preoperatively, 1 day postoperatively, at discharge, and during the last follow-up. Radiographic parameters included (Fig. 1): (1) segmental Cobb angles (between the superior and inferior endplates of the involved vertebra) and their correction values (the postoperative segmental Cobb angle minus the preoperative angle); (2) thoracic kyphosis (TK), (from the superior endplate of T4 to the inferior endplate of T12); (3) lumbar lordosis (LL) angle, (from the superior endplate of L1 to inferior endplate of L5); (4) thoracolumbar kyphosis (TLK) angle, (from the superior endplate of T10 to the inferior endplate of L2); (5) correction values of TK, TLK, and LL (postoperative angles minus preoperative angles); (6) proximal junctional angle (PJA), (from the inferior endplate of the uppermost instrumented vertebra [UIV] to the superior endplate of the UIV+2); and (7) segmental vertebral height (distance from the midpoint of the lower endplate of the adjacent upper vertebra to the midpoint of the upper endplate of the adjacent lower vertebra), and the height change (postoperative minus preoperative). Laboratory tests included white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and plasma procalcitonin measured preoperatively, postoperatively, at discharge, and during the last follow-up.

IBM SPSS for Windows ver. 27.0 (IBM Corp., Armonk, NY, USA) software was used for data analysis. Data are expressed as mean±standard deviation. The independent or paired-sample t-test was used for normally distributed data, and the independent or paired-sample Mann-Whitney U test was used for data that did not conform to a normal distribution. A p-value <0.05 was considered statistically significant.

A 70-year-old woman presented with progressive back pain and limited mobility 7 months after T12–L1 VA surgery, managed by prolonged bed rest. Needle biopsy and metagenomic next-generation sequencing (mNGS) confirmed the diagnosis of T12–L1 pyogenic spondylitis caused by oral streptococci (Fig. 5, Table 1). The preoperative ODI and VAS scores were 8/10 and 88.7, respectively. Surgical debridement and corpectomy via the spinal canal’s lateral wall approach were performed. At the last follow-up, the patient’s ODI and VAS scores improved to 5/10 and 53/100, respectively, with normal ambulation and no recurrence.

Eight patients who underwent PDC-SCLWA from January 2020 to May 2024 were included, with an average follow-up of 13 months (range, 7–29 months) (Table 1). The group comprised six females and two males, with an average age of 73.5±4.9 years. All patients underwent VA at other hospitals and were diagnosed with severe osteoporosis. The mean interval from augmentation to SIAVA diagnosis was 371±447 days (range, 7–1,400 days). At admission, five patients exhibited neurological deficits, including limb numbness, limb motor impairment, and limb pain, and the remaining three patients only experienced severe pain. Seven patients had comorbidities, including hypertension, diabetes, cerebral infarction, chronic bronchitis, pulmonary tuberculosis, and cancer, with an average CCI of 3.9±1.25. Preoperative inflammatory parameters included mean WBC 7.9±1.4×10⁹/L, CRP 35.2±18.8 mg/L, and ESR 70.8±23.2 mm/1st hr. The mean preoperative ODI was 7.6±0.9, and the mean VAS was 71.7±19.4.

All patients were diagnosed based on combined clinical manifestations, MRI, and CT, with pathogenic microorganism detection as the gold standard. Seven patients underwent mNGS of tissue fluids. M. tuberculosis was the most common pathogen, accounting for 37.5% (3/8) of positive cultures. In six patients, X-rays revealed varying degrees of bone cement leakage involving the spinal canal, intervertebral discs, and paravertebral soft tissues. The mean interval from SIAVA diagnosis to revision surgery was 8±5 days. The mean surgical duration was 290.6±63.3 minutes, and the average estimated blood loss was 775.0±388.1 mL (range, 400–1,600 mL). Intraoperative dural laceration occurred in two patients who subsequently experienced dizziness or headaches, but these symptoms improved after dural repair and postoperative rehydration. Postoperative ODI averaged 7.1±1.2, which decreased significantly to 4.3±0.9 at discharge after analgesic treatment (p<0.05).

VAS and ODI showed significant improvement from preoperative to the final follow-up assessments (Fig. 6). All patients reported varying degrees of symptom relief. The mean final follow-up ODI and VAS scores decreased significantly to 2.4±1.7 and 30.6±11.2, respectively (p<0.001). Seven patients achieved independent ambulation. One patient, preoperatively bedridden for years, could mobilize with a wheelchair.

Inflammatory markers displayed a downward trend from the preoperative to postoperative periods and the last follow-up (Fig. 6). Following appropriate antibiotic therapy, the levels of these markers approached normal. The mean WBC decreased significantly from 7.79±1.39×10⁹/L preoperatively to 5.55±1.45×10⁹/L at the last follow-up (p<0.05). Mean CRP decreased from 35.23±18.80 mg/L preoperatively to 12.24±11.66 mg/L (p<0.05), and ESR decreased from 70.75±23.22 mm/1st hr preoperatively to 38.00±29.76 mm/1st hr (p<0.05). No patient experienced recurrent infection at the final follow-up.

Radiological parameters showed significant postoperative improvement. The average preoperative segmental Cobb angle of six patients with thoracic infection was 30.8°±14.3°, with postoperative correction to 8.3°±3.9° (p<0.05). For two patients with lumbar infection, preoperative segmental Cobb angles improved from −5.9°±3.4° to −16.4°±2.9° (p<0.05), with a mean correction of 22.6°±10.5°. Infection sites involved thoracic, lumbar, and thoracolumbar (T11–L2) regions at rates of 12.5%, 75.0%, and 12.5%, respectively. TK, TLK, and LL showed improvement to varying extents (Table 2). There was no significant difference in the intervertebral height pre- and postoperatively. At the final follow-up, CT scans showed intervertebral fusion in seven patients, with one patient exhibiting fusion at the upper intervertebral space and posterolateral lamina but lacking fusion at the lower space. The overall intervertebral fusion rate was 87.5% (7/8), with 100% (7/7) posterolateral lamina fusion. The average preoperative PJA was 7.32°±5.06°, compared with 7.86°±6.86° at the last follow-up. One patient experienced a significant increase in PJA from 4.16° to 18.73° and was diagnosed with proximal junctional kyphosis (PJK) with a proximal junctional fracture. The remaining seven patients did not develop PJK.

SIAVA is a postoperative complication that is rare but destructive. Severe pain, neurological deficits, paralysis, and even death are common outcomes reported in an early case series. Abdelrahman et al. [15] described nine patients, including three fatalities and three with paralysis. Although consensus on managing SIAVA is lacking, spinal surgeons increasingly prefer revision and debridement surgery, which improves patient outcomes. Yuan et al. [9] reported a series of 33 patients, of whom 27 underwent surgical treatment and showed significant improvement in ambulatory function. In our study, eight patients treated with PDC-SCLWA experienced varying degrees of pain relief and functional improvement, and most (7/8) returned to normal activities. Some patients achieved better clinical outcomes than had existed before surgery. These findings emphasize the value of surgical treatment in improving the prognosis of patients with SIAVA.

Most studies have suggested that the combined anterior-posterior approach is preferred. Liao et al. [16] performed the combined approach in 10 of 18 patients, aiming for extensive debridement, adequate decompression, and reconstruction. A study by Yuan et al. [9] reported an average blood loss of 1,830 mL for the combined approach, indicating significant blood loss as a drawback. Additionally, prolonged operative time posed challenges for patients with SIAVA. Zhang et al. [17] reported a single posterior approach with a mean blood loss of 465.6±166.0 mL and mean operative duration of 175.0±16.8 minutes, both lower than those in combined approaches. Preliminary observations of PDC-SCLWA, with an average blood loss of 775.0±388.1 mL and surgical duration of 290.6±63.3 minutes, indicate advantages over combined approaches. Compared with the single posterior approach, PDC-SCLWA causes less trauma and preserves more anatomical structures. Zhang et al. [18] employed piezosurgery utilizing a single posterior approach for SIAVA to achieve adequate lesion removal with less tissue damage. In PDC-SCLWA, piezosurgery is routinely used, improving surgical precision, facilitating lesion removal, and minimizing damage to nerve roots or segmental arteries.

Restoration of spinal stability is the primary goal of surgical treatment. In patients with SIAVA, vertebral lesions alter stability and spinal curvature, including local Cobb angle, TK, TLK, and LL. Double titanium meshes were implanted into the vertebral space and posterior column structures were preserved to correct deformity and restore stability. In our study, the segmental Cobb angle improved significantly from 24.59°±15.74° preoperatively to 10.28°±2.89° postoperatively, with a mean correction of 22.6°±10.5°. Furthermore, based on different lesion segments, physiological angles, including TK, TLK, and LL, showed meaningful improvement. No significant angle loss was observed at the last follow-up. Due to posterior column support, the vertebral height was also maintained after vertebrectomy.

Intact posterior column structures are critical for maintaining spinal stability, according to previous biomechanical studies. Patients with SIAVA typically have severe osteoporosis, leading to a screw loosening rate of up to 60% after surgery. Screw loosening can subsequently cause PJK [19]. Hu et al. [20] reported two asymptomatic screw loosening cases following revision surgery. The PDC-SCLWA procedure preserves posterior anatomical structures, minimizes changes in the distribution of primary load, and prevents fractures at fixation segments [21]. Conversely, insufficient anterior support may increase localized stress at bone-screw interfaces, thereby promoting loosening [22]. Traditional posterior approaches involving posterior structure resection during debridement can compromise stability and increase the risk of postoperative screw breakage. Because the elastic modulus of pedicle screws significantly exceeds that of bone, the internal fixation system continues to bear most of the load even after fusion, potentially causing fatigue fractures. In this approach, the preservation of posterior structures shares load stress, reducing the likelihood of screw loosening or breakage.

The supraspinous ligament, part of the posterior ligamentous complex and defined posterior structures in this procedure, plays a key biomechanical role in the posterior ligamentous complex. Wu et al. [23] performed finite element analyses on the posterior ligamentous complex and showed that resection of the supraspinous ligament significantly increased the local range of motion during flexion and extension, shifting the instantaneous axis of rotation anteriorly (0.39 mm in flexion) and posteriorly (0.65 mm in extension). This indicates the supraspinous ligament’s importance in maintaining spinal stability. Similarly, Liu et al. [24] compared three fixation methods for thoracolumbar tuberculosis and found that posterior screw fixation, which preserves intact posterior structures, reduces stress on the internal fixation system (49.9 MPa during extension) and minimal bone stress around screws (28.7 MPa during rotation). Preserving posterior column structures thus distributes load more evenly, decreasing fixation failure, bone resorption, and screw loosening risks. Chen et al. [25] showed that total laminectomy significantly increased stress on adjacent discs (90% increase) during flexion compared with intact spines, whereas hemilaminectomy, which preserves partial lamina and ligaments, increased disc stress by only 21%. Preservation of the supraspinous and interspinous ligaments reduces the risk of adjacent segment degeneration.

In our study, the mean PJA was 7.32°±5.06° preoperatively and 7.86°±6.86° at the final follow-up, demonstrating no significant increase (p>0.05). One patient developed PJK 3 months postoperatively, with PJA increasing from 4.16° to 18.73°, and a proximal junctional fracture. Treatment with teriparatide, calcium supplements, and antiosteoporotic medication stabilized PJA. A meta-analysis confirmed teriparatide’s effectiveness in improving fusion rates, reducing screw loosening, and enhancing bone density in spinal fusion, leading to improved radiographic outcomes [26]. Additionally, the preserved lamina provides an ideal graft bed, which increases the fusion surface and enables multilevel anterior-posterior fusion. Kawaguchi et al. [27] reported that posterior interlaminar bone grafting effectively maintains sagittal balance. In our study, seven patients undergoing posterior laminar grafting achieved 100% fusion (7/7) by 3 months postoperatively. In one patient with incomplete anterior fusion, posterior interlaminar fusion was successful. Thus, PDC-SCLWA significantly benefits SIAVA treatment in osteoporotic patients, reducing PJK risk and enhancing fusion outcomes through posterior grafting.

Traditional posterior laminectomy can lead to the formation of epidural scars, causing nerve root irritation [28]. Preserving lamina and partial facet joints reduces scar tissue formation, preventing nerve deficit recurrence after revision surgery. No recurrence of pain or increase in VAS occurred during follow-up in our study. Furthermore, retaining posterior structures facilitates subsequent revision surgery by preserving essential anatomical landmarks, potentially reducing the incidence of intraoperative dural tears (previously reported as 15.9% [29]).

To the best of our knowledge, this is the first study to report the use of PDC-SCLWA in SIAVA, highlighting advantages such as reduced blood loss, shorter operative duration, effective debridement, and excellent surgical stability. However, this preliminary study has limitations, including a small sample size and a short follow-up period. Future studies with more extensive follow-up and additional patients are required to validate the long-term outcomes of this study. Additionally, the complexity of this procedure demands surgeons experienced in open spinal surgery and piezosurgery.

In conclusion, most patients undergoing VA are elderly and have multiple comorbidities. SIAVA significantly threatens their health and life, posing perioperative management challenges. PDC-SCLWA offers advantages by preserving posterior structures, minimizing spinal cord disruption, maintaining mechanical stability, and optimizing the bone graft bed for fusion. No severe intraoperative complications or recurrence occurred in our study. Therefore, PDC-SCLWA is a potentially safe and effective surgical alternative for the treatment of SIAVA.