Objective:To compare the clinical efficacy and analyze the surgical approach differences using CT parameters between mini-open transforaminal lumbar interbody fusion (MO-TLIF) and minimally invasive surgery of transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of degenerative lumbar diseases.Methods:A total of 68 consecutive patients with degenerative lumbar diseases undergoing surgery at the Second Affiliated Hospital of Soochow University from January 2022 to January 2023 were randomized into the MO-TLIF group (34 cases, percutaneous screw-assisted posterior midline MO-TLIF) and the MIS-TLIF group (34 cases, Wiltse approach MIS-TLIF using the Quadrant channel). Perioperative indicators (operative time, incision length, intraoperative blood loss, fluoroscopy frequency, postoperative bedrest duration, and hospital stay) and complications were compared. Visual analogue scale (VAS) and Oswestry disability index (ODI) were assessed preoperatively and at 3 days, 3 months, and 1 year postoperatively. Effective cross-sectional area (eCSA) of paraspinal muscles was evaluated on MRI preoperatively and 1 year postoperatively. CT parameters of surgical approaches, including spinous process-midline distance (SM), Wiltse-midline distance (WM), surgical approach angle, depth, and multifidus muscle displacement were compared. Pearson correlation and multivariate linear regression analyses were performed to explore associations between CT parameters, operative time, blood loss, and eCSA atrophy.Results:Baseline characteristics showed no significant differences between groups ( P>0.05). The MO-TLIF group exhibited shorter operative time (109.85±7.82 min vs. 133.82±20.22 min), reduced blood loss (77.21±21.83 ml vs. 141.18±31.44 ml), smaller incision length (6.09±0.22 cm vs. 7.00±0.43 cm), shorter bedrest duration (1.59±0.49 d vs. 2.38±0.50 d), and shorter hospital stay (8.93±1.44 d vs. 10.35±1.45 d), but higher fluoroscopy frequency (19.53±1.92 times vs. 16.29±1.78 times) compared to the MIS-TLIF group ( P<0.05). Complications included fat liquefaction (5 cases) and dural tears (2 cases). Both groups showed improved VAS and ODI postoperatively ( P<0.05). At 3 d postoperatively, the MO-TLIF group had lower VAS (2.74±0.47 points vs. 3.35±0.48 points) and ODI (27.46%±2.16% vs. 30.42%±2.52%) than the MIS-TLIF group ( P<0.05). Postoperative eCSA decreased significantly in the MIS-TLIF group ( P<0.05) but remained stable in the MO-TLIF group ( P>0.05). The MO-TLIF group demonstrated smaller SM (8.43±1.81 mm vs. 31.15±6.53 mm), approach angle, depth, and muscle displacement ( P<0.05). CT parameters in the MO-TLIF group showed no correlation with operative time, blood loss, or eCSA atrophy ( r<0.3, P>0.05), whereas parameters in the MIS-TLIF group correlated positively with these outcomes (0.3< r<0.6, P<0.05). Multivariate regression revealed a significant association between CT parameters and eCSA atrophy in the MIS-TLIF group ( R 2=0.474, P<0.05). Conclusion:Compared to MIS-TLIF, MO-TLIF reduces intraoperative blood loss, accelerates recovery, and minimizes paraspinal muscle trauma.

Objective:To compare the clinical efficacy and analyze the surgical approach differences using CT parameters between mini-open transforaminal lumbar interbody fusion (MO-TLIF) and minimally invasive surgery of transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of degenerative lumbar diseases.Methods:A total of 68 consecutive patients with degenerative lumbar diseases undergoing surgery at the Second Affiliated Hospital of Soochow University from January 2022 to January 2023 were randomized into the MO-TLIF group (34 cases, percutaneous screw-assisted posterior midline MO-TLIF) and the MIS-TLIF group (34 cases, Wiltse approach MIS-TLIF using the Quadrant channel). Perioperative indicators (operative time, incision length, intraoperative blood loss, fluoroscopy frequency, postoperative bedrest duration, and hospital stay) and complications were compared. Visual analogue scale (VAS) and Oswestry disability index (ODI) were assessed preoperatively and at 3 days, 3 months, and 1 year postoperatively. Effective cross-sectional area (eCSA) of paraspinal muscles was evaluated on MRI preoperatively and 1 year postoperatively. CT parameters of surgical approaches, including spinous process-midline distance (SM), Wiltse-midline distance (WM), surgical approach angle, depth, and multifidus muscle displacement were compared. Pearson correlation and multivariate linear regression analyses were performed to explore associations between CT parameters, operative time, blood loss, and eCSA atrophy.Results:Baseline characteristics showed no significant differences between groups ( P>0.05). The MO-TLIF group exhibited shorter operative time (109.85±7.82 min vs. 133.82±20.22 min), reduced blood loss (77.21±21.83 ml vs. 141.18±31.44 ml), smaller incision length (6.09±0.22 cm vs. 7.00±0.43 cm), shorter bedrest duration (1.59±0.49 d vs. 2.38±0.50 d), and shorter hospital stay (8.93±1.44 d vs. 10.35±1.45 d), but higher fluoroscopy frequency (19.53±1.92 times vs. 16.29±1.78 times) compared to the MIS-TLIF group ( P<0.05). Complications included fat liquefaction (5 cases) and dural tears (2 cases). Both groups showed improved VAS and ODI postoperatively ( P<0.05). At 3 d postoperatively, the MO-TLIF group had lower VAS (2.74±0.47 points vs. 3.35±0.48 points) and ODI (27.46%±2.16% vs. 30.42%±2.52%) than the MIS-TLIF group ( P<0.05). Postoperative eCSA decreased significantly in the MIS-TLIF group ( P<0.05) but remained stable in the MO-TLIF group ( P>0.05). The MO-TLIF group demonstrated smaller SM (8.43±1.81 mm vs. 31.15±6.53 mm), approach angle, depth, and muscle displacement ( P<0.05). CT parameters in the MO-TLIF group showed no correlation with operative time, blood loss, or eCSA atrophy ( r<0.3, P>0.05), whereas parameters in the MIS-TLIF group correlated positively with these outcomes (0.3< r<0.6, P<0.05). Multivariate regression revealed a significant association between CT parameters and eCSA atrophy in the MIS-TLIF group ( R 2=0.474, P<0.05). Conclusion:Compared to MIS-TLIF, MO-TLIF reduces intraoperative blood loss, accelerates recovery, and minimizes paraspinal muscle trauma.

Objective:To investigate the related factors of vertebral body height reloss after pedicle screw fixation of thoracolumbar fracture and to determe the optimum prediction point.Methods:A retrospective case control study was made on 215 patients with thoracolumbar fracture admitted to Second Affiliated Hospital of Soochow University from January 2010 to December 2017. There were 155 males and 60 females，aged 21-80 years［（48.6±10.4）years］. According to Denis fracture classification，there were 73 patients with compression fractures（type A in 15 patients，type B in 51，type C in 7），135 burst fractures（type A in 28 patients，type B in 87，type C in 20）and flexion distraction fractures（type A in 4，type B in 2，type C in 1）. All patients were treated by pedicle screw fixation. Follow-up lasted for 12- 48 months［（23.8±8.2）months］. Vertebral body height loss occurred in 86 patients（loss group），but did not in 129 patients（non-loss group）. The two groups were compared concerning sex，age，osteoporosis self-assessment tool for Asians（OSTA），body mass index（BMI），fracture types，number of fractured vertebrae，preoperative sagittal Cobb angle，preoperative degree of vertebral compression，number of screws placed in injured vertebrae，extent of vertebral reset and other related factors. Univariate analysis was used to identify the correlation of those factors with vertebral body height reloss. Multivariate Logistic regression analysis was performed to identify the independent factors for the height reloss with the receiver operating characteristic curve（ROC）and area under the curve（AUC）calculated to evaluate the optimum point in prediction of vertebral height reloss.Results:The two groups showed no significant differences in sex，age，BMI，fracture types，number of injured vertebrae，preoperative sagittal Cobb angle and number of screws placed in injured vertebrae（ P>0.05），but the differences were statistically significant in OSTA，preoperative degree of vertebral compression and extent of vertebral reset（ P<0.05）. According to the univariate analysis，OSTA，preoperative degree of vertebral compression and extent of vertebral reset were significantly correlated with the occurrence of vertebral body height reloss（ P<0.05）. According to the multivariate Logistic regression，OSTA（ OR=1.109，95% CI 0.527-0.685， P<0.05）and preoperative degree of vertebral compression（ OR =0.038，95% CI 0.539-0.689， P<0.05）were significantly related to vertebral body height reloss. The AUC relating OSTA and preoperative degree of vertebral compression to vertebral body height reloss was 0.604 and 0.614，respectively. The optimum prediction point of OSTA and preoperative degree of vertebral compression for vertebral body height reloss was 1.9 and 31.3%，respectively. Conclusions:OSTA and the preoperative degree of vertebral compression are independent risk factors for vertebral body height reloss. OSTA≤1.9 or preoperative degree of vertebral compression ≥31.3% indicates a significantly higher risk of postoperative vertebral body height reloss.