Feasibility and clinical efficacy of minimally invasive techniques in the treatment of type Ⅱ/Ⅲ brucellar spondylitis.

OBJECTIVE: To explore the clinical feasibility and perioperative superiority of combined minimally invasive techniques in treating type II/III Brucellar Spondylitis (BS), clarify the stratified surgical indications for different minimally invasive procedures and key technical points, provide evidence-based medical evidence for selecting appropriate surgical methods in the clinical treatment of type II/III BS, and provide a reference for formulating clinical norms for minimally invasive techniques in treating BS, thereby promoting the standardized and popularized application of minimally invasive spinal surgery techniques in the treatment of BS. Limitations of the retrospective single-center design and mixed minimally invasive intervention heterogeneity are fully discussed to avoid overgeneralized inference. METHODS: A retrospective controlled study was conducted with stratified subgroup description of different minimally invasive procedures and clear preoperative allocation criteria for surgical approaches to reduce selection bias. Patients diagnosed with type II/III BS and undergoing surgical treatment in our hospital from January 2020 to March 2025 were selected as the research subjects. They were divided into the minimally invasive group and the traditional open surgery group according to standardized preoperative surgical allocation criteria based on abscess scale, vertebral destruction range, spinal instability degree and spinal canal occupation ratio. The minimally invasive group integrated three types of distinct minimally invasive techniques including unilateral biportal endoscopy (UBE), percutaneous spine endoscopy, and CT-guided lesion drainage combined with minimally invasive percutaneous internal fixation; baseline lesion characteristics of patients receiving different minimally invasive modalities were separately described to reflect intervention heterogeneity. The open group underwent conventional anterior or posterior open debridement, bone graft fusion, and pedicle screw internal fixation. Through postoperative follow-up, the clinical baseline data, perioperative core indicators, pain visual analogue scale (VAS) score, Oswestry Disability Index (ODI), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) inflammatory indicators, ASIA neurological function grading, radiological bone fusion rate, postoperative complication occurrence rate and disease recurrence rate of the two groups of patients were systematically compared. Effect size calculation and minimal clinically important difference (MCID) analysis were supplemented for all continuous outcome indicators to distinguish statistical difference from clinical meaningful difference. RESULTS: A total of 72 patients met the inclusion criteria, among which 38 were in the minimally invasive group and 34 were in the open surgery group. There were no statistically significant differences in clinical data such as gender, age, type of BS, affected vertebrae segments, presence of paravertebral abscess, and ASIA classification of neurological function between the two groups (P > 0.05); supplementary stratified comparison of abscess size, vertebral destruction severity and spinal canal occupation ratio between groups was performed to further verify intergroup clinical comparability, indicating good comparability. The minimally invasive group was significantly superior to the open group in perioperative indicators including operation time, intraoperative blood loss, surgical incision length, postoperative bed rest time, and hospital stay (P < 0.05), with medium-to-large effect sizes confirming clinical meaningful gaps. At 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively, the reductions in VAS score, ODI, ESR, and CRP in the minimally invasive group were significantly greater than those in the open group (P < 0.05), and MCID thresholds were reached in most time points, representing clinically meaningful pain relief and inflammatory improvement. The excellent and good rate of neurological function recovery was 90.9% in the minimally invasive group and 75.0% in the open group, with no significant difference between the two groups (P > 0.05). The bone fusion rate was 92.1% in the minimally invasive group and 88.2% in the open group, showing comparable spinal fusion effects (P > 0.05). The postoperative complication rate was 21.05% in the minimally invasive group, significantly lower than 76.47% in the open group (P < 0.05), with large effect size supporting clinical safety advantages. At 12-month follow-up, the disease recurrence rate was 2.6% in the minimally invasive group and 8.8% in the open group, with no significant difference between the two groups (P > 0.05). CONCLUSION: Minimally invasive spine surgery techniques are safe and feasible in the treatment of Type Ⅱ/Ⅲ BS, achieving thorough debridement, reliable infection control reflected by reduced inflammatory markers, and sufficient nerve decompression. They are comparable to conventional open surgery in neurological recovery, clinical efficacy and spinal fusion outcomes, while possessing significant perioperative advantages such as less surgical trauma, less intraoperative bleeding, faster postoperative recovery, and lower complication rate. Considering the retrospective design, mixed minimally invasive intervention heterogeneity and lack of long-term follow-up beyond 12 months, minimally invasive techniques may serve as a preferred alternative surgical option for appropriately selected Type Ⅱ/Ⅲ BS patients who meet strict minimally invasive surgical indications, rather than a universal first-line scheme for all Type Ⅱ/Ⅲ BS cases.