With the continuous advances in modern medical technology and equipment,minimally invasive surgery (MIS) is widely applied in clinical practice.Ultrasound (US) as a real-time,portable,and radiation-free medical imaging method can be used for the intraoperative guidance in MIS to ensure safe and effective surgery.However,the physical characteristics of conventional US fail to display some tissue structures of the human body due to the existence of gas and bone.US-based navigation can make up for the deficiencies by advanced imaging technologies including spatial orientation,image reconstruction,and multi-modality image fusion,being real-time,accurate,and radiation-free.Therefore,US-guided robots can achieve safe,effective,and minimally invasive operation in MIS.This paper reviews the studies of US-guided robots in MIS and prospects the development of this field.
Humans ; Robotics/methods* ; Minimally Invasive Surgical Procedures/methods* ; Ultrasonography ; Spinal Fusion/methods* ; Ultrasonography, Interventional/methods*

OBJECTIVE: To explore the feasibility and accuracy of ultrasound volume navigation (UVN) combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation through a prospective randomized controlled study. METHODS: Patients with thoracic and lumbar vertebral fractures scheduled for percutaneous pedicle screw fixation between January 2022 and January 2023 were enrolled. Among them, 60 patients met the selection criteria and were included in the study. There were 28 males and 32 females, with an average age of 49.5 years (range, 29-60 years). The cause of injury included 20 cases of traffic accidents, 21 cases of falls, 17 cases of slips, and 2 cases of heavy object impact. The interval from injury to hospital admission ranged from 1 to 5 days (mean, 1.57 days). The fracture located at T ₁₂ in 15 cases, L ₁ in 20 cases, L ₂ in 19 cases, and L ₃ in 6 cases. The study used each patient as their own control, randomly guiding pedicle screw implantation using UVN combined with X-ray fluoroscopy on one side of the vertebral body and the adjacent segment (trial group), while the other side was implanted under X-ray fluoroscopy (control group). A total of 4 screws and 2 rods were implanted in each patient. The implantation time and fluoroscopy frequency during implantation of each screw, angle deviation and distance deviation between actual and preoperative planned trajectory by imaging examination, and the occurrence of zygapophysial joint invasion were recorded. RESULTS: In terms of screw implantation time, fluoroscopy frequency, angle deviation, distance deviation, and incidence of zygapophysial joint invasion, the trial group showed superior results compared to the control group, and the differences were significant ( P<0.05). CONCLUSION UVN combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation can yreduce screw implantation time, adjust dynamically, reduce operational difficulty, and reduce radiation damage.
Male ; Female ; Humans ; Middle Aged ; Pedicle Screws ; Prospective Studies ; X-Rays ; Surgery, Computer-Assisted/methods* ; Spinal Fusion/methods* ; Fluoroscopy/methods* ; Lumbar Vertebrae/injuries*

OBJECTIVE: To evaluate the feasibility of S₂ alar iliac screw insertion in Chinese children using computerized three-dimension reconstruction and simulated screw placement technique, and to optimize the measurement of screw parameters. METHODS: A total of 83 pelvic CT data of children who underwent pelvic CT scan December 2018 to December 2020 were retrospectively analyzed, excluding fractures, deformities, and tumors. There were 44 boys and 39 girls, with an average age of (10.66±3.52) years, and were divided into 4 groups based on age (group A:5 to 7 years old;group B:8 to 10 years old;group C:11-13 years old;group D:14 to 16 years old). The original CT data obtained were imported into Mimics software, and the bony structure of the pelvis was reconstructed, and the maximum and minimum cranial angles of the screws were simulated in the three-dimensional view with the placement of 6.5 mm diameter S2 alar iliac screws. Subsequently, the coronal angle, sagittal angle, transverse angle, total length of the screw, length of the screw in the sacrum, width of the iliac, and distance of the entry point from the skin were measured in 3-Matic software at the maximum and minimum head tilt angles, respectively. The differences among the screw parameters of S₂ alar iliac screws in children of different ages and the differences between gender and side were compared and analyzed. RESULTS: In all 83 children, 6.5 mm diameter S₂ iliac screws could be placed. There was no significant difference between the side of each screw placement parameter. The 5 to 7 years old children had a significantly smaller screw coronal angle than other age groups, but in the screw sagittal angle, the difference was more mixed. The 5 to 7 years old children could obtain a larger angle at the maximum head tilt angle of the screw, but at the minimum cranial angle, the larger angle was obtained in the age group of 11 to 13 years old. There were no significant differences among the age groups. The coronal angle and sagittal angle under maximum cephalic angle and minimum cranial angle of 5 to 7 years old male were (40.91±2.91)° and (51.85±3.75)° respectively, which were significantly greater than in female. The coronal angle under minimum cranial angle was significantly greater in girls aged 8-10 years old than in boys. For the remaining screw placement angle parameters, there were no significant differences between gender. The differences in the minimum iliac width, the screw length, and the length of the sacral screws showed an increasing trend with age in all age groups. The distance from the screw entry point to the skin in boys were significantly smaller than that of girls. The minimum width of the iliac in boys at 14 to 16 years of age were significantly wider than that in girls at the same stage. In contrast, in girls aged 5 to 7 years and 11 to 13 years, the screw length was significantly longer than that of boys at the same stage. CONCLUSION The pelvis of children aged 5 to 16 years can safely accommodate the placement of 6.5 mm diameter S₂ alar iliac screws, but the bony structures of the pelvis are developing and growing in children, precise assessment is needed to plan a reasonable screw trajectory and select the appropriate screw length.
Humans ; Male ; Female ; Child ; Adolescent ; Child, Preschool ; Ilium/surgery* ; Retrospective Studies ; Feasibility Studies ; Bone Screws ; Pelvis ; Sacrum/surgery* ; Spinal Fusion/methods*

OBJECTIVE: To explore clinical features, treatment methods and clinical effects of cervical spondylosis with proximal muscular atrophy. METHODS: Eleven patients with proximal-type cervical spondylotic amyotrophy were retrospectively studied from September 2016 to November 2020, including 7 males and 4 females, aged 38 to 68 years old. Clinical symptoms, MRI and neuroelectrophysiological manifestations were analyzed, and patients were treated with conservative treatment or anterior cervical decompression fusion surgery, respectively. The efficacy was evaluated by manual muscle test (MMT) before and after treatment, and patients' satisfaction was followed up at the same time. RESULTS: All patients were followed up for 6 to 19 months. All 11 patients were unilateral, mainly manifested by atrophy of deltoid muscle, supraspinatus muscle and infraspinatus muscle, and may be accompanied by ipsilateral neck and shoulder pain at early stage. MRI showed lesions at C_4,5, C_5,6 segments were more common. Electrophysiological examination showed the affected muscle was denervated, and amplitude of compound muscle action potential (CMAP) of innervated nerve on the affected side was lower than that on the healthy side. All patients were obtained bone fusion. One patient who were underwent anterior cervical corpectomy and fusion (ACCF) occurred developed contralateral C5 nerve root paralysis after operation, which recovered completely after 10 weeks of symptomatic treatment. At 12 months after operation, the efficacy was evaluated according to MMT, 3 patients were treated conservatively, 2 patients excellent and 1 good;in 8 patients treated by operation, 3 patients were excellent, 4 good, and 1 moderate. CONCLUSION The incidence of cervical spondylosis with proximal muscular atrophy is low, which is manifested as unilateral proximal muscle atrophy and may be accompanied by ipsilateral neck and shoulder pain in the early stage. Combined with MRI and neuroelectrophysiological examination, misdiagnosis could be reduced. In the early stage of disease, especially in the case of nucleus pulposus protrusion leading to nerve compression, conservative treatment could be taken. When the conservative treatment is ineffective or the pain cannot be tolerated, anterior decompression surgery is recommended, and the overall effect is satisfactory.
Male ; Female ; Humans ; Adult ; Middle Aged ; Aged ; Retrospective Studies ; Shoulder Pain ; Cervical Vertebrae/pathology* ; Muscular Atrophy/surgery* ; Decompression, Surgical/methods* ; Spondylosis/surgery* ; Treatment Outcome ; Spinal Fusion/adverse effects*

OBJECTIVE: To explore the feasibility and clinical effect of Stand-alone oblique lateral interbody fusion (OLIF) in the treatment of lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis. METHODS: A retrospective analysis was performed on 16 cases with lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis admitted to three medical centers from January 2015 to December 2018. There were 6 males and 10 females, the age ranged from 45 to 67 years old with an average of (55.48±8.07) years old, the medical history ranged from 36 to 240 months with an average of (82.40±47.68) months. The lesion sites included L_2,3 in 2 cases, L_3,4 in 5 cases, and L_4,5 in 9 cases. All patients presented with chronic low back pain with lower limb neurological symptoms in 3 cases. All patients were treated by Stand-alone oblique lateral lumbar interbody fusion. Clinical and radiological findings and complications were observed. RESULTS: There was no vascular injury, endplate injury and vertebral fracture during the operation. The mean incision length, operation time, and intraoperative blood loss were(4.06±0.42) cm, (45.12±5.43) min, (33.40±7.29) ml, respectively. The mean visual analogue scale (VAS) of the incision pain was (1.14±0.47) at 72 hours after operation. There was no incision skin necrosis, poor incision healing or infection in patients. Sympathetic chain injury occurred in 1 case, anterolateral pain and numbness of the left thigh in 2 cases, and weakness of the left iliopsoas muscle in 1 case, all of which were transient injuries with a complication rate of 25%(4/16). All 16 patients were followed up from 12 to 36 months with an average of (20.80±5.46) months. The intervertebral space height was significantly recovered after operation, with slight lost during the follow-up. Coronal and sagittal balance of the lumbar spine showed good improvement at the final follow-up. There was no obvious subsidence or displacement of the cage, and the interbody fusion was obtained. At the final follow-up, Japanese Orthopaedic Association(JOA) score and Oswestry disability index(ODI) were significantly improved. CONCLUSION As long as the selection of case is strict enough and the preoperative examination is sufficients, the use of Stand-alone OLIF in the treatment of lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis has a good results, with obvious clinical advantages and is a better surgical choice.
Male ; Female ; Humans ; Child, Preschool ; Intervertebral Disc Degeneration/surgery* ; Retrospective Studies ; Sclerosis ; Treatment Outcome ; Lumbar Vertebrae/surgery* ; Spinal Fusion/methods*

OBJECTIVE: To assess the clinical effects of percutaneous endoscopic surgery through two different approaches for stable degenerative lumbar spondylolisthesis. METHODS: Sixty-four patients with stable degenerative lumbar spondylolisthesis who underwent percutaneous endoscopic procedures between January 2016 and December 2019 were divided into transforaminal approach group and interlaminar approach group according to surgical approaches, 32 patients in each group. There were 16 males and 16 females in transforaminal approach group, aged from 52 to 84 years old with an average of (66.03±9.60) years, L₂ slippage in 4 cases, L₃ slippage in 5, and L₄ slippage in 23. There were 17 males and 15 females in interlaminar approach group, aged from 46 to 81 years old with an average of (61.38±9.88) years, L₃ slippage in 3 cases, L₄ slippage in 15, and L₅ slippage in 14. Operative time, intraoperative fluoroscopy times, and postoperative bedtime were compared between two groups. Anteroposterior displacement values, interbody opening angles, and the percentage of slippage were measured on preoperative and postoperative 12-month dynamic radiographs. Visual analogue scale (VAS) of low back pain and lower extremity pain, and the Japanese Orthopaedic Association (JOA) score before and after surgery were observed, and clinical effects were evaluated according to the modified MACNAB criteria. RESULTS: All operations were successfully completed, and patients in both groups were followed up for more than 1 year, and without complications during follow-up period. ①There was no significant difference in operation time between two groups(P>0.05). Intraoperative fluoroscopy times were longer in transforaminal approach group than that in intervertebral approach group(P<0.05). Postoperative bedtime was shorter in transforaminal approach group than that in intervertebral approach group (P<0.05).② No lumbar instability was found on dynamic radiography at 12 months postoperatively in both groups. There were no significant differences in anteroposterior displacement values, interbody opening angles, and the percentage of slippage between two groups postoperative 12 months and preoperative 1 day(P>0.05). ③There was no significant difference between two groups in VAS of low back pain at 3 days and 1, 12 months after the operation compared with the preoperative(P>0.05), but the VAS of the lower extremity pain was significantly improved compared with the preoperative(P<0.05). Both of groups showed significant improvement in JOA score at 12 months compared with preoperatively(P<0.05). There was no significant difference in VAS of low back pain, lower extremity pain and JOA scores between two groups during the same period after surgery(P>0.05). According to modified Macnab criteria, excellent, good, fair and poor outcomes were 21, 7, 3 and 1 in transforaminal approach group respectively, and which in intervertebral approach group were 20, 7, 5 and 0, there was no significant difference in clinical effect between the groups(P>0.05). CONCLUSION Intervertebral approach may reduce intraoperative fluoroscopy times and transforaminal approach can shorten postoperative bedtime, both approaches achieve satisfactory results in the treatment of stable degenerative lumbar spondylolisthesis with no progression of short-term slippage.
Male ; Female ; Humans ; Middle Aged ; Aged ; Aged, 80 and over ; Spondylolisthesis/surgery* ; Low Back Pain/surgery* ; Treatment Outcome ; Lumbar Vertebrae/surgery* ; Spinal Fusion/methods* ; Retrospective Studies

OBJECTIVE: To investigate whether 3D-printed artificial vertebral body can reduce prosthesis subsidence rate for patients with cervical chordomas, through comparing the rates of prosthesis subsidence between 3D printing artificial vertebral body and titanium mesh for anterior spinal reconstruction after total spondylectomy. METHODS: This was a retrospective analysis of patients who underwent surgical treatment for cervical chordoma at our hospital from March 2005 to September 2019. There were nine patients in the group of 3D artificial vertebral body (3D group), and 15 patients in the group of titanium mesh cage (Mesh group). The patients' characteristics and treatment data were extracted from the medical records, including age, gender, CT hounsfield unit of cervical vertebra and surgical information, such as the surgical segments, time and blood loss of surgery, frequency and degree of prosthesis subsidence after surgery. Radiographic observations of prosthesis subsidence during the follow-up, including X-rays, CT, and magnetic resonance imaging were also collected. SPSS 22.0 was used to analysis the data. RESULTS: There was no significant difference between the two groups in gender, age, CT hounsfield unit, surgical segments, time of surgery, blood loss of posterior surgery and total blood loss. Blood loss of anterior surgery was 700 (300, 825) mL in 3D group and 1 500 (750, 2 800) mL in Mesh group (P < 0.05). The prosthesis subsidence during the follow-up, 3 months after surgery, there was significant difference between the two groups in mild prosthesis subsidence (P < 0.05). The vertebral height of the 3D group decreased less than 1 mm in eight cases (no prosthesis subsidence) and more than 1 mm in one case (mild prosthesis subsidence). The vertebral height of the Mesh group decreased less than 1 mm in five cases (no prosthesis subsidence), and more than 1 mm in eight cases (mild prosthesis subsidence). Two patients did not have X-rays in 3 months after surgery. There was a statistically significant difference between the two groups in the prosthesis subsidence rate at the end of 12 months (P < 0.01). The vertebral height of eight cases in the 3D group decreased less than 1 mm (no prosthesis subsidence) and one case more than 3 mm (severe prosthesis subsidence). Four of the 15 cases in the Mesh group decreased less than 1 mm (no prosthesis subsidence), two cases more than 1 mm (mild prosthesis subsidence), and nine cases more than 3 mm (severe prosthesis subsidence). There was a statistically significant difference between the two groups in the prosthesis subsidence rate at the end of 24 months (P < 0.01). The vertebral height of seven cases in the 3D group decreased less than 1 mm (no prosthesis subsidence), one case more than 3 mm (severe prosthesis subsidence), and one case died with tumor. One case in the Mesh group decreased less than 1 mm (no prosthesis subsidence), one case more than 1 mm (mild prosthesis subsidence), 11 case more than 3 mm (severe prosthesis subsidence), one case died with tumor and one lost the follow-up. Moreover, at the end of 12 months and 24 months, there was significant difference between the two groups in severe prosthesis subsidence rate (P < 0.01). CONCLUSION 3D-printed artificial vertebral body for anterior spinal reconstruction after total spondylectomy for patients with cervical chordoma can provide reliable spinal stability, and reduce the incidence of prosthesis subsidence after 2-year follow-up.
Humans ; Chordoma/surgery* ; Retrospective Studies ; Vertebral Body ; Titanium ; Cervical Vertebrae/surgery* ; Printing, Three-Dimensional ; Spinal Fusion/methods* ; Treatment Outcome

To investigate the effects of postoperative fusion implantation on the mesoscopic biomechanical properties of vertebrae and bone tissue osteogenesis in idiopathic scoliosis, a macroscopic finite element model of the postoperative fusion device was developed, and a mesoscopic model of the bone unit was developed using the Saint Venant sub-model approach. To simulate human physiological conditions, the differences in biomechanical properties between macroscopic cortical bone and mesoscopic bone units under the same boundary conditions were studied, and the effects of fusion implantation on bone tissue growth at the mesoscopic scale were analyzed. The results showed that the stresses in the mesoscopic structure of the lumbar spine increased compared to the macroscopic structure, and the mesoscopic stress in this case is 2.606 to 5.958 times of the macroscopic stress; the stresses in the upper bone unit of the fusion device were greater than those in the lower part; the average stresses in the upper vertebral body end surfaces were ranked in the order of right, left, posterior and anterior; the stresses in the lower vertebral body were ranked in the order of left, posterior, right and anterior; and rotation was the condition with the greatest stress value in the bone unit. It is hypothesized that bone tissue osteogenesis is better on the upper face of the fusion than on the lower face, and that bone tissue growth rate on the upper face is in the order of right, left, posterior, and anterior; while on the lower face, it is in the order of left, posterior, right, and anterior; and that patients' constant rotational movements after surgery is conducive to bone growth. The results of the study may provide a theoretical basis for the design of surgical protocols and optimization of fusion devices for idiopathic scoliosis.
Humans ; Scoliosis/surgery* ; Spinal Fusion/methods* ; Lumbar Vertebrae/surgery* ; Osteogenesis ; Biomechanical Phenomena/physiology* ; Finite Element Analysis

OBJECTIVE: To investigate the feasibility of predicting proximal junctional kyphosis (PJK) in adults after spinal deformity surgery based on back-forward Bending CT localization images and related predictive indicators. METHODS: A retrospective analysis was performed for 31 adult patients with spinal deformity who underwent posterior osteotomy and long-segment fusion fixation between March 2017 and March 2020. There were 5 males and 26 females with an average age of 62.5 years (range, 30-77 years). The upper instrumented vertebrae (UIV) located at T ₅ in 1 case, T ₆ in 1 case, T ₉ in 13 cases, T ₁₀ in 12 cases, and T ₁₁ in 4 cases. The lowest instrumented vertebrae (LIV) located at L ₁ in 3 cases, L ₂ in 3 cases, L ₃ in 10 cases, L ₄ in 7 cases, L ₅ in 5 cases, and S ₁ in 3 cases. Based on the full-length lateral X-ray film of the spine in the standing position before and after operation and back-forward Bending CT localization images before operation, the sagittal sequence of the spine was obtained, and the relevant indexes were measured, including thoracic kyphosis (TK), lumbar lordosis (LL), local kyphosis Cobb angle (LKCA) [the difference between the different positions before operation (recovery value) was calculated], kyphosis flexibility, hyperextension sagittal vertical axis (hSVA), T ₂-L ₅ hyperextension C ₇-vertebral sagittal offset (hC ₇-VSO), and pre- and post-operative proximal junctional angle (PJA). At last follow-up, the patients were divided into PJK and non-PJK groups based on PJA to determine whether they had PJK. The gender, age, body mass index (BMI), number of fusion segments, number of cases with coronal plane deformity, bone mineral density (T value), UIV position, LIV position, operation time, intraoperative blood loss, osteotomy grading, and related imaging indicators were compared between the two groups. The hC ₇-VSO of the vertebral body with significant differences between groups was taken, and the receiver operating characteristic curve (ROC) was used to evaluate its accuracy in predicting the occurrence of PJK. RESULTS: All 31 patients were followed up 13-52 months, with an average of 30.0 months. The patient's PJA was 1.4°-29.0° at last follow-up, with an average of 10.4°; PJK occurred in 8 cases (25.8%). There was no significant difference in gender, age, BMI, number of fusion segments, number of cases with coronal plane deformity, bone mineral density (T value), UIV position, LIV position, operation time, intraoperative blood loss, and osteotomy grading between the two groups ( P>0.05). Imaging measurements showed that the LL recovery value and T ₈-L ₃ vertebral hC ₇-VSO in the PJK group were significantly higher than those in the non-PJK group ( P>0.05). There was no significant difference in hyperextension TK, hyperextension LL, hyperextension LKCA, TK recovery value, LL recovery value, kyphosis flexibility, hSVA, and T ₂-T ₇, L ₄, L ₅ vertebral hC ₇-VSO ( P>0.05). T ₈-L ₃ vertebral hC ₇-VSO was analyzed for ROC curve, and combined with the area under curve and the comprehensive evaluation of sensitivity and specificity, the best predictive index was hC ₇-L ₂, the cut-off value was 2.54 cm, the sensitivity was 100%, and the specificity was 60.9%. CONCLUSION Preoperative back-forward Bending CT localization image can be used to predict the occurrence of PJK after posterior osteotomy and long-segment fusion fixation in adult spinal deformity. If the patient's T ₈-L ₂ vertebral hC ₇-VSO is too large, it indicates a higher risk of postoperative PJK. The best predictive index is hC ₇-L ₂, and the cut-off value is 2.54 cm.
Male ; Female ; Humans ; Adult ; Middle Aged ; Retrospective Studies ; Blood Loss, Surgical ; Thoracic Vertebrae/surgery* ; Kyphosis/surgery* ; Lordosis/surgery* ; Spinal Fusion/methods* ; Tomography, X-Ray Computed ; Postoperative Complications/diagnostic imaging* ; Lumbar Vertebrae/surgery*

OBJECTIVE: To explore the effectiveness of a new point contact pedicle navigation template (referred to as "new navigation template" for simplicity) in assisting screw implantation in scoliosis correction surgery. METHODS: Twenty-five patients with scoliosis, who met the selection criteria between February 2020 and February 2023, were selected as the trial group. During the scoliosis correction surgery, the three-dimensional printed new navigation template was used to assist in screw implantation. Fifty patients who had undergone screw implantation with traditional free-hand implantation technique between February 2019 and February 2023 were matched according to the inclusion and exclusion criteria as the control group. There was no significant difference between the two groups ( P>0.05) in terms of gender, age, disease duration, Cobb angle on the coronal plane of the main curve, Cobb angle at the Bending position of the main curve, the position of the apical vertebrae of the main curve, and the number of vertebrae with the pedicle diameter lower than 50%/75% of the national average, and the number of patients whose apical vertebrae rotation exceeded 40°. The number of fused vertebrae, the number of pedicle screws, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were compared between the two groups. The occurrence of implant complications was observed. Based on the X-ray films at 2 weeks after operation, the pedicle screw grading was recorded, the accuracy of the implant and the main curvature correction rate were calculated. RESULTS: Both groups successfully completed the surgeries. Among them, the trial group implanted 267 screws and fused 177 vertebrae; the control group implanted 523 screws and fused 358 vertebrae. There was no significant difference between the two groups ( P>0.05) in terms of the number of fused vertebrae, the number of pedicle screws, the pedicle screw grading and accuracy, and the main curvature correction rate. However, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were significantly lower in trial group than in control group ( P<0.05). There was no complications related to screws implantation during or after operation in the two groups. CONCLUSION The new navigation template is suitable for all kinds of deformed vertebral lamina and articular process, which not only improves the accuracy of screw implantation, but also reduces the difficulty of operation, shortens the operation time, and reduces intraoperative bleeding.
Humans ; Orthopedic Procedures ; Pedicle Screws ; Retrospective Studies ; Scoliosis/surgery* ; Spinal Fusion/methods* ; Spine ; Surgery, Computer-Assisted/methods*