The Cortical Bone Trajectory Screw Technique Assisted by the Mazor Renaissance Robotic System as a Salvage Strategy for Failed Lumbar Spine Surgery: Technical Note and Case Series.

Purpose: The objective of this study was to describe the Mazor Renaissance robotic system-assisted CBT (cortical bone trajectory) screw technique as a salvage strategy for failed lumbar spine surgery. Patients and Methods: Between January 2018 and June 2022, 7 patients underwent salvage surgery with the CBT screw fixation technique assisted by the Mazor Renaissance robot system in our institution. Intraoperative observations were recorded for blood loss, duration of operation, and fluoroscopy time. Complications related to CBT screws were also recorded. The accuracy of CBT screws was recorded in accordance with the modified Gertzbein-Robbins classification. The JOA (Japanese Orthopedic Association) score for low back pain was used to evaluate surgical outcomes. Results: A total of 26 CBT screws were placed in 7 patients, including 4 females and 3 males. Three patients underwent ASD (adjacent segment disease) and four patients underwent lumbar union failure with loose or compromised PSs (pedicle screws). The mean operation time was 129.29 ± 32.97 minutes, the mean blood loss was 180 ± 52.60 mL, and the mean intraoperative fluoroscopy time was 14.29 ± 3.15 s. All screws were clinically acceptable according to the Gertzbein-Robbins classification. There were no complications related to CBT screws in any of the cases. The JOA scores for low back pain of all patients were significantly improved at the final follow-up. Conclusion: The CBT screw fixation technique supplemented the traditional PS fixation technique, which can be performed as a salvage strategy for failed lumbar spine surgery and achieved good clinical results. The spinal robot was very helpful in evaluating pedicle size and determining CBT screw direction, especially in a previously instrumented lumbar pedicle.

Surgical Strategy and Outcomes of Full Endoscopic Lumbar Discectomy for Recurrent Lumbar Disk Herniation Following a Previous Full Endoscopic Lumbar Discectomy.

OBJECTIVE: Recurrent lumbar disc herniation (RLDH) cannot be prevented after full endoscopic lumbar discectomy (FELD), and the optimal surgical treatment for RLDH after FELD remains controversial. The aim of the study was to suggest a surgical strategy for FELD to treat RLDH following a previous FELD and to present surgical outcomes. METHODS: Between February 2015 and March 2022, 68 patients with RLDH were surgically treated with FELD retrospectively. An original approach was suggested for the treatment of early recurrence (24 h-2 weeks). The full endoscopic transforaminal technique (FETD) was considered for patients requiring local anesthesia, and in RLDH with FETD indications or FEID technological difficulties. The full endoscopic interlaminar technique (FEID) was chosen in RLDH with FEID indications. Both FEID and FETD were suitable if no FEID or FETD technological difficulties existed. Clinical efficacy was evaluated using the visual analog scale (VAS) score, Oswestry disability index (ODI), and modified MacNab criteria. Postoperative follow-up data at 24 h, 3 months, and final-follow-up were recorded. Operation time and clinical outcomes were assessed with t test. p-value < 0.05 was considered statistically significant. RESULTS: All 68 patients had an average follow-up time of 23.8 months (range, 6-76 months). In the 13 cases of early recurrence, the operation time (32.30 ± 9.67 vs. 58.00 ± 6.16 min) in the original surgical approach group was shorter than that in the changing surgical approach group (p < 0.05). In the 28 cases of L4/5 FETD recurrence (>2 weeks), the operation time (66.17 ± 12.18 vs. 53.60 ± 5.45 min) in the FETD group was more than that in the FEID group (p < 0.05). In the 22 cases of L5S1 recurrence (>2 weeks), the operation time (55.75 ± 8.79 vs. 79.33 ± 6.65 min) in the FEID group was shorter than in the FETD group (p < 0.05). The postoperative VAS and ODI scores at 24 h, 3 months, and final-follow up were all significantly improved, compared with their preoperative counterparts (p < 0.05). Based on the modified MacNab criteria, 88.23% of patients showed excellent or good results. Re-recurrence occurred in three patients at 3 months. No surgical complications were observed in any of the 68 cases. CONCLUSION: FELD is a safe and effective treatment option for RLDH with previous FELD. For early recurrence, the original approach was suggested. Both FEID and FETD were effective and safe for recurrence (>2 weeks), but FEID seemed more efficient for L4/5 RLDH after previous FETD and for L5S1 RLDH.

Application of the oblique lateral interbody fusion technique in salvage surgery: technical note and case series.

Objective: The oblique lateral interbody fusion (OLIF) technique is a promising interbody fusion technique. This study summarizes the technical aspects of OLIF as a salvage surgery and the preliminary outcomes of a series of cases. Patients and methods: A retrospective review of patients with leg or back pain induced by pseudoarthrosis or adjacent segment disease after posterior lumbar interbody fusion/transforaminal lumbar interbody fusion was done. These patients underwent salvage OLIF surgeries in our institution from January 2021 to March 2022. Variables such as the demographic, clinical, surgical, and radiological characteristics of the enrolled patients were recorded and analyzed. Results: Eight patients (five females and three males; mean age 69.1 ± 5.7 years, range 63-80 years) were enrolled in this study. The mean operative time was 286.25 min (range: 230-440 min), and the estimated blood loss was 90 ml (range: 50-150 ml). Only one of the eight patients experienced a complication of lower limb motor weakness, which disappeared within 5 days after surgery. The latest data showed that the mean intervertebral space height increased from 8.36 mm preoperatively to 12.70 mm and the mean segmentary lordosis increased from 8.92° preoperatively to 15.05°. Bone fusion was achieved in all but one patient, who was followed up for only 3 months. The JOA scores Japanese Orthopaedic Association (JOA) Scores for low back pain of all patients significantly improved at the final follow-up. Conclusion: OLIF provides a safe and effective salvage strategy for patients with failed posterior intervertebral fusion surgery. Patients effectively recovered intervertebral and foraminal height with no additional posterior direct decompression.

Differentiation of benign versus malignant indistinguishable vertebral compression fractures by different machine learning with MRI-based radiomic features.

OBJECTIVES: To explore an optimal machine learning (ML) model trained on MRI-based radiomic features to differentiate benign from malignant indistinguishable vertebral compression fractures (VCFs). METHODS: This retrospective study included patients within 6 weeks of back pain (non-traumatic) who underwent MRI and were diagnosed with benign and malignant indistinguishable VCFs. The two cohorts were retrospectively recruited from the Affiliated Hospital of Qingdao University (QUH) and Qinghai Red Cross Hospital (QRCH). Three hundred seventy-six participants from QUH were divided into the training (n = 263) and validation (n = 113) cohort based on the date of MRI examination. One hundred three participants from QRCH were used to evaluate the external generalizability of our prediction models. A total of 1045 radiomic features were extracted from each region of interest (ROI) and used to establish the models. The prediction models were established based on 7 different classifiers. RESULTS: These models showed favorable efficacy in differentiating benign from malignant indistinguishable VCFs. However, our Gaussian naïve Bayes (GNB) model attained higher AUC and accuracy (0.86, 87.61%) than the other classifiers in validation cohort. It also remains the high accuracy and sensitivity for the external test cohort. CONCLUSIONS: Our GNB model performed better than the other models in the present study, suggesting that it may be more useful for differentiating indistinguishable benign form malignant VCFs. KEY POINTS: • The differential diagnosis of benign and malignant indistinguishable VCFs based on MRI is rather difficult for spine surgeons or radiologists. • Our ML models facilitate the differential diagnosis of benign and malignant indistinguishable VCFs with improved diagnostic efficacy. • Our GNB model had the high accuracy and sensitivity for clinical application.

Application of electromagnetic navigation in endoscopic transforaminal lumbar interbody fusion: a cohort study.

STUDY DESIGN: Clinical retrospective cohort study. OBJECTIVES: To explore the application of the electromagnetic navigation system in Endo-TLIF. MATERIALS AND METHODS: From May 2019 to March 2020, 76 patients with single-segment lumbar spondylolisthesis treated by electromagnetic navigation-assisted Endo-TLIF (NE group) and conventional Endo-TLIF (CE group) were enrolled in the study. Time of pedicle screw implantation, entire operation time, the number of intraoperative X-ray fluoroscopy exposures, total blood loss, incision length, ambulation time, accuracy of pedicle screws, complications, visual analog scale for back and leg pain, Oswestry Disability Index, Japanese Orthopedic Association score and postoperative fusion rates were recorded, respectively. RESULTS: There were no significant differences in preoperative demographics between the NE and CE groups (P > 0.05). The mean number of intraoperative X-ray fluoroscopy exposures, guidewires insertion, entire operation time, total blood loss and adjustment rate of screws in the NE group were significantly less compared with the CE group (P < 0.05, respectively). There were no significant differences in clinical parameters between the two groups at different time points in the follow-up period (P > 0.05). There was no statistical difference in fusion rates between the two groups. In addition, one case of cage subsidence was observed after surgery in the CE group. CONCLUSION: Electromagnetic navigation systems could be applied throughout the entire surgical course and ameliorate the shortcomings of the conventional Endo-TLIF technique to reduce radiation exposure, improve accuracy, avoid repetitive operations and shorten surgery time and the required learning curve of the procedure. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Nomograms for Predicting Recurrent Herniation in PETD with Preoperative Radiological Factors.

PURPOSE: To investigate the preoperative radiological risk factors for recurrent lumbar disc herniation (rLDH) within 1 year after percutaneous endoscopic transforaminal discectomy (PETD). PATIENTS AND METHODS: A retrospective case-control study was conducted. Between January 2013 and November 2019, a total of 1210 patients with single-level L4/5 LDH who underwent PETD were enrolled in the present study. In total, 62 rLDH patients were diagnosed and collected based on the clinical and radiological manifestations, and 224 non-rLDH controls were selected from the remaining 1148 patients. Preoperative radiological parameters were collected and measured. An age threshold to distinguish patients into subgroups was established using the Youden index. The relationships between the risk factors and rLDH were evaluated by univariate and multivariate analyses in two subgroups. Predictive models were established based on logistic analysis. The area under the curve (AUC) of receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA) were used to assess the predictive models. RESULTS: In the present study, logistic analysis identified six significant predictors associated with rLDH in the young group: superior endplate concave angle (ECA), sacral slope, Modic changes, sagittal range of motion (sROM), extension intervertebral angle (IVA), and lumbar lordosis. Four significant predictors were identified in the elderly group: disc height index (DHI), retrolisthesis (posterior spondylolisthesis), sROM, and extension IVA. Validation of both models demonstrated excellent model discrimination (AUC= 0.940 and 0.946, respectively). DCA also showed excellent clinical utility and benefits. CONCLUSION: The nomograms that we constructed could accurately predict individual patient recurrence risk. Individualized measures should be taken for patients of different ages with the above risk factors, and tailored postoperative surveillance of patients who underwent PETD can be planned.