Objective To define a safe distance range from the LC-Ⅱ screw trajectory to the apex of the greater sciatic notch based on pelvic CT measurements, and to clinically assess the feasibility of using this range under obturator outlet view combined with iliac tangential view fluoroscopy to guide screw insertion. Methods CT scans of 104 normal pelvises collected between January 2022 and February 2025 were analyzed. There were 52 males and 52 females, with a median age of 45.8 years (range, 19-76 years). The RadiAnt DICOM Viewer software was used to reconstruct coronal, sagittal, and axial sections of the potential LC-II screw trajectory. The maximum safety distance (Dmax) and the optimal safety distance (Dopt) from this trajectory to the greater sciatic notch were measured on the coronal and sagittal views. A retrospective analysis was conducted on 21 patients with LC-Ⅱ type pelvic fractures treated with the LC-Ⅱ screws fixation. And the screws were placed within the pre-defined safe distance under guidance from the obturator outlet and iliac tangential views. Postoperative CT scans were obtained to evaluate the accuracy of screw placement. Results Radiographic measurements from the 104 cases showed that Dmax ranged from 1.87 to 3.87 cm (mean, 2.79 cm), and Dopt ranged from 1.01 to 2.92 cm (mean, 1.84 cm). Both Dmax and Dopt were significantly greater in the males than in the females (P>0.05). No significant difference was found between the left and right sides within the same gender (P>0.05). All 21 patients successfully underwent fracture reduction and fixation, with a total of 23 LC-Ⅱscrews implanted. According to the Lonstein grading system, the screw placement accuracy was rated as excellent in 16 screws, good in 3, fair in 3, and poor in 1, with an excellent and good rate of 82.6%. ConclusionUtilizing a CT-defined safe distance range from the screw trajectory to the greater sciatic notch, and adhering to this range under obturator outlet view combined with iliac tangential view fluoroscopy, enables the accurate and precise placement of LC-Ⅱ screws.
Objective To investigate the technical key points and effectiveness of ultrasonic bone scalpel-assisted anterior controllable antedisplacement and fusion (ACAF) for treating cervical ossification of the posterior longitudinal ligament (OPLL). Methods Between June 2022 and December 2024, 11 OPLL patients underwent ultrasonic bone scalpel-assisted ACAF. The cohort included 8 males and 3 females, aged 49-74 years (mean, 56.7 years). The OPLL classification included 5 cases of mixed-type, 4 cases of segmental-type, and 2 cases of continuous-type cases. Ossification involved 2-5 spinal segments (mean, 3.2). Disease duration ranged from 2 to 18 months (mean, 6.2 months). The operation time, intraoperative blood loss, and complications were recorded. Pain improvement was assessed using the visual analogue scale (VAS) score, and neurological function was evaluated using Japanese Orthopaedic Association (JOA) score. Postoperative cervical CT and MRI were performed to measure spinal canal encroachment rate, spinal canal area, and spinal cord sagittal diameter. Results All operations were successfully completed. The operation time ranged from 174 to 360 minutes (mean, 255.9 minutes). The intraoperative blood loss ranged from 170 to 530 mL (mean, 345.9 mL). The C5 nerve root palsy occurred in 1 patient. No cerebrospinal fluid leakage, aggravated spinal cord injury, or recurrent/superior laryngeal nerve injuries occurred. All patients were followed 3-12 months (mean, 7.2 months). At last follow-up, VAS scores significantly decreased and JOA scores significantly increased compared to preoperative values (P<0.05). According to the JOA improvement rate, the effectiveness was rated as excellent in 2 cases, good in 8, and fair in 1, with an excellent and good rate of 90.9%. Radiological re-examination revealed no implant loosening, screw breakage, or aggravated spinal stenosis. Postoperative spinal canal encroachment rate significantly decreased, while spinal canal area and spinal cord sagittal diameter significantly increased compared to preoperative measurements (P<0.05). Conclusion For the treatment of cervical OPLL via ACAF, the intraoperative application of ultrasonic bone scalpel-assisted osteotomy enables precise vertebral groove creation and mobilization of the vertebra-ossification complex, thereby enhancing surgical safety and achieving satisfactory short-term effectiveness.
Objective To design the surgical strategy of percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for bilateral lumbar spinal stenosis (LSS) and to evaluate the effectiveness. Methods The percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for bilateral LSS was designed according to the pathological features of LSS. The technique was used to treat 42 patients with LSS between January 2016 and January 2018. There were 18 males and 24 females with an average age of 61.7 years (range, 46-81 years). The duration of symptoms was 1-20 years, with an average of 9.7 years. The surgical segment at L4, 5 were 27 cases, at L5, S1 were 15 cases. The operation time and perioperative complications were recorded. Lumbar X-ray, CT, and MRI examinations were performed at 1 week, 3 months, and 1 year after operation. Visual analogue scale (VAS) score was used to evaluate the low back pain and leg pain, Oswestry disability index (ODI) was used to evaluate the lumbar function, and single continuous walking distance (SCWD) was used to evaluate lower extremity nerve function. The clinical efficacy was evaluated by MacNab criteria at 1 year after operation. Results All patients underwent surgery successfully. The operation time was 68-141 minutes with an average of 98.2 minutes. All 42 patients were followed up 12-24 months with an average of 18.8 months. There were 2 cases of dural tears during operation, and 1 case of transient dysfunction of the lower limbs of the decompression channel after operation. All of them were cured after corresponding treatment. No serious complications such as death, major bleeding, or irreversible nerve injury occurred during follow-up. No segmental instability was found according to postoperative lumbar hyperextension and flexion X-ray films, and postoperative CT and MRI imaging showed that the stenotic lumbar spinal canal was significantly enlarged, and the compression of the nerve root was sufficient. The VAS score of low back pain and leg pain, ODI score, and SCWD at each time point after operation were significantly improved when compared with those before operation (P<0.05); the indexes were significantly improved over time after operation, and the differences were significantly (P<0.05). The clinical efficacy was evaluated by MacNab standard at 1 year after operation, and the results were excellent in 18 cases, good in 20 cases, fair in 3 cases, and poor in 1 case. The excellent and good rate was 90.5%. Conclusion The percutaneous full-endoscopic bilateral decompression via unilateral posterior approach for LSS is a safe and effective procedure. A well-designed surgical strategy and mastery of its technical points are important guarantees for successful operation and satisfactory results.