OBJECTIVE: To investigate the early clinical efficacy of single-position O-arm navigation-assisted oblique lateral interbody fusion(OLIF) combined with minimally invasive percutaneous pedicle screw fixation(PPS) in the treatment of lumbar spondylolisthesis. METHODS: A retrospective analysis was conducted on 22 patients with lumbar spondylolisthesis who underwent OLIF-PPS surgery including 11 males and 11 females with a mean age of (64.6±1.5) years old ranging from 49 to 80 years old between April 2021 and June 2023. All patients presented with lumbosacral pain, lower limb radiating pain, numbness, and had poor responses to conservative treatment. Surgical time, intraoperative blood loss, hospital stay, and postoperative complications were recorded. Clinical outcomes were evaluated using the visual analogue scale(VAS) and Oswestry disability index(ODI) preoperatively at 3 days after operation and the final follow-up. Standing lumbar anteroposterior and lateral X-rays were performed to measure disc height(DH), slippage degree, vertebral reduction rate, pedicle screw accuracy, and cage subsidence. RESULTS: All surgeries were successfully completed with a mean follow-up of (27.1±2.2) months (range 18 to 36 months). The mean surgical time was (76.1±12.2) min (range 60 to 93 min), intraoperative blood loss was (86.3±32.2) ml (range 40 to 113 ml), and hospital stay was (7.1±1.2) days. Postoperative VAS significantly improved from (7.2±0.7) preoperatively to (2.3±0.5) at 3 days after operation and (1.7±0.2) at the final follow-up (P<0.05). ODI decreased from (68.5±7.2)% preoperatively to (30.3±3.1)% at 3 days after operation and (16.6±1.6)% at the final follow-up (P<0.05). DH increased from (8.5±1.7) mm preoperatively to (18.1±1.4) mm at 3 days after operation and (17.2±1.1) mm at the final follow-up (P<0.05). Slippage degree improved from (24.1±4.6)% preoperatively to (10.3±4.2)% at 3 days after operation and (10.1±3.2)% at the final follow-up (P<0.05). A total of 88 pedicle screws were implanted with an excellent rate of 98% (86/88). Complications included transient left hip flexion weakness (2 cases) and left anteromedial thigh pain (1 case), all resolved during follow-up. No incision hematoma, infection, screw loosening, or cage subsidence occurred. CONCLUSION Single-position O-arm navigation-assisted OLIF combined with PPS demonstrates satisfactory early clinical efficacy for lumbar spondylolisthesis, with advantages including minimal invasiveness, significant pain relief, effective vertebral reduction, and low complication rates.
Humans ; Male ; Female ; Spondylolisthesis/diagnostic imaging* ; Middle Aged ; Aged ; Spinal Fusion/methods* ; Lumbar Vertebrae/diagnostic imaging* ; Minimally Invasive Surgical Procedures/methods* ; Pedicle Screws ; Aged, 80 and over ; Retrospective Studies

OBJECTIVE: To investigate the efficacy and safety of oblique lateral interbody fusion(OLIF) channel technique combined with pedicle screw internal fixation in the treatment of single-segment lumbar intervertebral space/vertebral body infection. METHODS: A retrospective analysis was conducted on 23 patients who underwent surgical treatment for lumbar infection from January 2021 to December 2022. The patients were divided into the OLIF channel group and the traditional open surgery group according to the surgical methods. There were 16 cases in the OLIF channel group, including 9 males and 7 females, with an average age of (68.5±12.1) years old;there were 7 cases in the traditional open surgery group, including 4 males and 3 females, with an average age of (75.0±3.2) years old. The operation time, intraoperative blood loss, hospital stay, incision length, visual analogue scale(VAS), activities of daily living (ADL) score, Oswestry disability index (ODI), erythrocyte sedimentation rate(ESR), C-reactive protein(CRP) before and 1 week and 3 months after the operation, and the intervertebral fusion status on the last follow-up CT were compared between the two groups. RESULTS: Compared with the open surgery group, the OLIF channel group had shorter operation time (209.87±31.5) min vs. (246.0±42.7) min, less intraoperative blood loss (225.625±91.1) ml vs. (364.2±74.8) ml, and shorter incision length (6.1±1.2) vs. (14.0±1.4) cm, and the differences were statistically significant(P<0.05). Before and 1 week and 3 months after the operation, the lumbar VAS in the OLIF group were (6.3±0.6), (2.8±0.7), (1.1±0.5), and those in the traditional open surgery group were (6.4±0.6), (3.4±0.5), (1.2±0.3);the ADL scores in the OLIF group were (45.0±4.5), (60.3±4.3), (94.1±4.2), and those in the open group were (46.4±5.6), (60.7±4.5), (92.9±4.9); the ODI scores in the OLIF group were (86.3±2.9)%, (69.5±4.1)%, (23.0±3.2)%, and those in the open group were (87.3±3.8)%, (69.8±4.2)%, (23.8±3.6)%, all of which showed significant improvement(P<0.05). Three months after the operation, CRP, PCT, and ESR were significantly lower than those before the operation, and CRP and PCT returned to normal, while ESR was still slightly elevated in some patients. The last follow-up CT showed that continuous trabecular bone formation was observed between the upper and lower endplates of the surgical segments in all patients, and the fusion time was (8.7±4.5) months. CONCLUSION The OLIF channel technique combined with posterior internal fixation is a minimally invasive and effective treatment method, which can effectively control infection, relieve pain, and improve the quality of life of patients. Compared with traditional open surgery, it has the advantages of minimally invasive, shorter operation time, and less intraoperative blood loss.
Humans ; Male ; Female ; Spinal Fusion/methods* ; Lumbar Vertebrae/microbiology* ; Aged ; Middle Aged ; Retrospective Studies ; Aged, 80 and over ; Pedicle Screws ; Infections/surgery*

OBJECTIVE: To investigate the effect of the sequence of intermediate instrumentation and distraction-reduction of the injured vertebra on the surgical efficacy of short-segment percutaneous pedicle screw fixation for thoracolumbar burst fractures with high rate of spinal canal encroachment. METHODS: From January 2016 to January 2022, 38 patients with thoracolumbar burst fractures with high rate of spinal canal encroachment (spinal canal encroachment rate >40%, complete posterior longitudinal ligament, no flipping bone block in the posterior marginal of the vertebra) without spinal cord injury who were were treated with short-segment percutaneous pedicle screw fixation were retrospectively analyzed. During the operation, 18 cases were used distraction-reduction first and then intermediate instrumentation on injured vertebral and sequential distraction-reduction again(the distraction-reduction first group) including 8 females and 10 males with a mean age of 46.5 (38.5, 50.0) years old, and the other 20 cases were used intermediate instrumentation on injured vertebral first and then direct distraction-reduction(the intermediate instrumentation first group) including 10 males and 10 females with a mean age of 46.0 (35.8, 50.8) years. The anterior height ratio of the injured vertebra, local Cobb's angle of the injured vertebrae, the spinal canal encroachment rate, and the improvement rate of spinal canal encroachment were compared and evaluated. RESULTS: All patients were followed up for more than 1 year, and no complications such as spinal cord and root injury, screw loosening and screw rod fracture were found. The anterior height ratio of the injured vertebra, local Cobb' angle of the injured vertebra in the two groups were significantly improved compared with preoperative data(P<0.05), and those at 3 months and 1 year after operation was lost compared with that at the previous time point(P<0.05). Although the spinal canal encroachment rate of the two groups 1 day and 1 year after operation was improved compared with that before operation(P<0.05), the improvement of spinal canal volume in the distraction-reduction first group was significantly better than that in the intermediate instrumentation first group (P<0.01). CONCLUSION In the treatment of patients with thoracolumbar fractures with high rate of spinal canal encroachment, short-segment percutaneous pedicle screw internal fixation with distraction-reduction first and then intermediate instrumentation and sequential distraction-reduction again can more effectively reduce the bony encroachment in the spinal canal and achieve indirect decompression effect better.
Humans ; Female ; Male ; Adult ; Middle Aged ; Spinal Fractures/surgery* ; Thoracic Vertebrae/surgery* ; Lumbar Vertebrae/surgery* ; Fracture Fixation, Internal/instrumentation* ; Pedicle Screws ; Retrospective Studies ; Spinal Canal/surgery*

OBJECTIVE: To establish a two-segment vertebrectomy model using the finite element method, and to measure and compare the biomechanical properties of the lower cervical anterior transpedicular root screw (ATPRS) plate system, lower cervical anterior pedicle screw (ATPS) plate system, and lower cervical anterior cervical locked-plate (ACLP) system on this model. METHODS: CT data of the cervical spine (C₀-T₁) from a 34-year-old healthy adult male volunteer were collected. A nonlinear complete model of the lower cervical spine (C₃-C₇) was established using Mimics 10.01 software, based on which the ATPRS fixation model, ATPS fixation model, and ACLP fixation model were constructed respectively. An axial pressure of 75 N and a pure couple moment of 1.5 N·m were applied to C3 to make the model perform flexion-extension, left-right lateral bending, and left-right rotation movements. The range of motion (ROM) and stress distribution of each model under different working conditions were compared. RESULTS: The ROM of the C₄-C₇ segments in the ACLP group, ATPS group, and ATPRS group was reduced to 0.65° (-95.2%), 0.58° (-95.7%), and 0.62° (-95.4%) respectively compared with the intact model during flexion-extension movement;during lateral bending movement, it was reduced to 0.58° (-95.2%), 0.51°(-95.8%), and 0.60° (-95.1%) respectively;during rotation movement, it was reduced to 1.17° (-89.6%), 1.26° (-88.8%), and 1.27°(-88.7%) respectively. In terms of the stress on the titanium mesh graft, the ATPS group and ATPRS group had the maximum load during extension and the minimum load during flexion. Compared with the ACLP group, the stress on the titanium mesh graft in ATPS and ATPRS decreased by (-33.7%) and (-15.8%) in flexion, (-29.4%) and (-13.2%) in extension, (-26.2%) and (-23.4%) in lateral bending, and (-18.8%) and (-5.4%) in rotation, respectively. In terms of bone-screw interface stress, the peak bone stress near the C₇ screw in the ACLP group, ATPS group, and ATPRS group increased by 49.2%, 45.0%, and 47.6% respectively compared with the peak bone stress near the C₄ screw during extension. However, during flexion and lateral bending, there was no significant difference in the peak bone stress near the C₄ and C₇ screws. During rotation, the difference between the peak bone stress near the C₄ screw and that near the C₇ screw showed that in the ACLP group, left rotation (37.6%) was similar to right rotation (36.7%), while in the ATPS group and ATPRS group, left rotation was lower than right rotation. CONCLUSION Compared with the ACLP group, the ATPS group and ATPRS group have greater fixation stiffness and more stable fixation. However, in rotational movement, due to the uneven distribution of fixation stiffness, the stress distribution during torsion is uneven, but it is still better than the ACLP group. This indicates that ATPRS, like ATPS, has good primary stability, providing favorable conditions for bone graft fusion.
Humans ; Finite Element Analysis ; Male ; Cervical Vertebrae/physiopathology* ; Adult ; Biomechanical Phenomena ; Bone Plates ; Bone Screws ; Range of Motion, Articular ; Fracture Fixation, Internal

OBJECTIVE: To investigate the accuracy and safety of pedicle screw placement using 3D-printed auxiliary guides in scoliosis correction surgery for adolescents. METHODS: A retrospective analysis was conducted on the clinical data of 51 patients who underwent posterior scoliosis correction surgery from January 2020 to March 2023. Among them, there were 35 cases of adolescent idiopathic scoliosis and 16 cases of congenital scoliosis. The patients were divided into two groups based on the auxiliary tool used:the 3D-printed auxiliary guide screw placement group (3D printing group) and the free-hand screw placement group (free-hand group, without auxiliary tools). The 3D printing group included 32 patients (12 males and 20 females) with an average age of (12.59±2.60) years;the free-hand group included 19 patients (7 males and 12 females) with an average age of (14.58±3.53) years. The two groups were compared in terms of screw placement accuracy and safety, spinal correction rate, intraoperative blood loss, number of intraoperative fluoroscopies, operation time, hospital stay, and preoperative and last follow-up scores of the Scoliosis Research Society-22 (SRS-22) questionnaire. RESULTS: A total of 707 pedicle screws were placed in the two groups, with 441 screws in the 3D printing group and 266 screws in the free-hand group. All patients in both groups successfully completed the surgery. There was a statistically significant difference in operation time between the two groups (P<0.05). The screw placement accuracy rate of the 3D printing group was 95.46% (421/441), among which the Grade A placement rate was 89.34% (394/441);the screw placement accuracy rate of the free-hand group was 86.47% (230/266), with a Grade A placement rate of 73.31% (195/266). There were statistically significant differences in the accuracy of Grade A, B, and C screw placements between the two groups (P<0.05), while no statistically significant differences were observed in intraoperative blood loss, number of fluoroscopies, correction rate, or hospital stay (P>0.05). In the SRS-22 questionnaire scores, the scores of functional status and activity ability, self-image, mental status, and pain of patients in each group at the last follow-up were significantly improved compared with those before surgery (P<0.05), but there were no statistically significant differences in all scores between the two groups (P>0.05). CONCLUSION In scoliosis correction surgery, compared with traditional free-hand screw placement, the use of 3D-printed auxiliary guides for screw placement significantly improves the accuracy and safety of screw placement and shortens the operation time.
Humans ; Male ; Scoliosis/surgery* ; Female ; Adolescent ; Printing, Three-Dimensional ; Retrospective Studies ; Pedicle Screws ; Child

PURPOSE: Hoffa fracture is a femoral condyle fracture in the coronal plane. The lateral condyle is more commonly involved. The diagnosis is often difficult to detect with routine radiographs. Conservative management in this type of fracture resulted in nonunion, malunion, and other complications, such as stiff knee. Therefore, surgical management is mandatory in displaced fractures. Previous studies suggest only application of cancellous screw fixation, but these are not enough to counter vertical shear stress. Therefore, this study will evaluate the clinical outcomes of open reduction and internal fixation of Letenneur type I Hoffa fracture using cancellous screws with posterior buttressing plate. METHOD: This was a prospective cohort study conducted from March 2017 to July 2022 in orthopaedics department of tertiary care center after approval of institutional ethical committee. The study included 36 patients with Letenneur type I fractures treated by open reduction and internal fixation using posterior buttress plate and cancellous screws. Radiographs and clinical outcomes, range of movement (ROM), bone union, and knee society score (KSS) of patients were assessed at the end of 4 and 12 months in the follow-ups. All statistical analysis was done using Epi info version 7.2.1.0. RESULTS: In the 36 patients with Letenneur type I fracture, the majority belong to younger age group between 25 and 54 years with 22 males and 14 females. The modes of injury were road traffic accidents in 25 patients and fall from height in 11 patients. The right knee was involved in 21 cases and left was involved in 15 cases. Lateral condyle involvement was seen in 27 cases and medial condyle in 9 cases. All 36 patients with Letenneur type I Hoffa fracture were evaluated 4 months after surgical intervention. The notable improvements were observed in terms of ROM 120.4° ± 5.0° and KSS 85.0 ± 4.2. At the 12-month follow-up, considerably better outcomes were maintained regarding ROM 128.1° ± 5.2° and KSS 89.3 ± 4.8 with p < 0.05 which was statistically significant. At the final follow-up, all patients had routine fracture healing with a union time of (3.2 ± 3.4) months. CONCLUSIONS Fixation of Letenneur type I Hoffa fracture with cancellous screws and posterior buttress plate is effective, reliable and capable of providing adequate stability. Buttress plate assisted fixation is a valuable enhancement of the conventional technique of lag screw fixation of Hoffa fractures.
Humans ; Bone Plates ; Male ; Female ; Fracture Fixation, Internal/instrumentation* ; Adult ; Prospective Studies ; Middle Aged ; Femoral Fractures/surgery* ; Bone Screws ; Range of Motion, Articular ; Young Adult ; Aged ; Hoffa Fracture

PURPOSE: Percutaneous ilio-sacral screw (ISS) insertion using conventional C-arm fluoroscopy has been a widely employed technique for pelvic posterior ring fixation, particularly in developing regions. However, this approach presents technical challenges, leading to a high malposition rate. We introduced a new method for ISS insertion without additional equipment or software and suggested whether it could reduce the malposition rate and operating time. METHODS: This is a retrospective cohort study. The study included all patients who underwent percutaneous ISS fixation between January 2020 and December 2022. Patients treated with open reduction or other types of implants were excluded. The patients were divided into 2 groups based on the screw insertion method: Group A utilized the traditional dual-plane adjustment method, while Group B received the newly introduced method. In all cases, conventional C-arm fluoroscopy was the sole guidance during the surgical procedure. Malposition rate, radiation exposure, and operating time were compared between groups. Post-operative CT scans were used to assess screw accuracy using the Smith grading method. The Student's t-test or the Mann-Whitney U test was chosen for comparing the quantitative variables based on the normality test results. The Chi-squared test was utilized for comparing qualitative variables. RESULTS: A total of 72 patients with pelvic posterior ring disruption treated with percutaneous ISS under conventional fluoroscopy guidance were included in this study. Among them, 32 patients were in Group A and 40 patients were in Group B. In Group B, the average operation duration per screw was 33 min with 29 fluoroscopy applications, which was significantly lower than that in Group A (44 min, p < 0.001, 38 times, p < 0.001, respectively). Furthermore, the post-operative CT scan revealed that only 10.7% (6/56) of screws in Group B were inappropriately positioned according to the Smith criteria. CONCLUSION The novel method introduced in this study demonstrated a reduction in both malposition rates and operating time compared to the traditional dual-plane adjustment method. Precise pre-operative CT planning in conjunction with conventional fluoroscopy could establish this method as a widely applicable technique for percutaneous ISS fixation.
Humans ; Fluoroscopy/methods* ; Retrospective Studies ; Bone Screws ; Female ; Male ; Tomography, X-Ray Computed/methods* ; Sacrum/diagnostic imaging* ; Middle Aged ; Operative Time ; Adult ; Fracture Fixation, Internal/methods* ; Ilium/diagnostic imaging* ; Aged

PURPOSE: Bone cement-reinforced fenestrated pedicle screws (FPSs) have been widely used in the internal fixation and repair of the spine with osteoporosis in recent years and show significant improvement in fixation strength and stability. However, compared with conventional reinforcement methods, the advantages of bone cement-reinforced FPSs remain undetermined. This article compares the effects of fenestrated and conventional pedicle screws (CPSs) combined with bone cement in the treatment of osteoporosis. METHODS: A clinical control study of FPSs and CPSs combined with bone cement reinforcement in osteoporotic vertebral internal fixation was performed using the database PubMed, Embase, Cochrane Library, CNKI, the Wanfang, and the China Biomedical Literature Service System. Two evaluators screened the relevant literature in strict accordance with the inclusion criteria (diagnosis of participants, type of clinical study, treatment with FPS and CPS, and outcome indicators) and exclusion criteria (duplicate literature and missing or incorrect data) and independently conducted data extraction and quality evaluation. Clinical control studies of direct comparison between FPS and CPS combined with bone cement reinforcement in patients who were definitively diagnosed with thoracolumbar fractures or spinal degenerative diseases were included. Quality evaluation was conducted using the Cochrane risk bias evaluation tool for randomized controlled studies and using the Newcastle-Ottawa scale for retrospective case-control studies. RevMan software (version 5.3) was used for the meta-analysis to compare the clinical efficacy, radiological results, and related complications of the 2 methods. RESULTS: A total of 13 articles were included, including 7 randomized controlled studies and 6 retrospective case-control studies. There were 909 patients in these studies, 451 in the FPS and polymethyl methacrylate (FPS & PMMA) group and 458 in the CPS and polymethyl methacrylate (CPS & PMMA) group. The results of the meta-analysis showed that there was no significant difference between the 2 groups in operation time, hospital stay, visual analogue score, Japanese orthopaedic association score, Oswestry disability index score, Cobb angle, vertebral body deformation index and fusion rate (p > 0.05). The mean difference of intraoperative bleeding volume was -10.45, (95% confidence intervals (CI) (-16.92, -3.98), p = 0.002), the mean difference of loss height of the anterior edge of the vertebral body after surgery was -0.69 (95% CI (-0.93, -0.44), p < 0.001), and the relative risk (RR) of overall complication rate was 0.43 (95% CI (0.27, 0.68), p < 0.001), including the RR of bone cement leakage rate was 0.57 (95% CI (0.39, 0.85), p = 0.005). The screw loosening rate (RR = 0.26, 95% CI (0.13, 0.54), p < 0.001) of the FPS group was significantly lower than that of the CPS group. CONCLUSION The existing clinical evidence shows that compared with the CPS combined with bone cement, the use of FPS repair in the internal fixation of an osteoporotic vertebral body can reduce the amount of intraoperative bleeding, be more conducive to maintaining the height of the vertebral body, and significantly reduce the incidence of postoperative complications such as bone cement leakage and screw loosening.
Humans ; Pedicle Screws ; Bone Cements ; Spinal Fractures/surgery* ; Osteoporotic Fractures/surgery* ; Fracture Fixation, Internal/instrumentation*

PURPOSE: The fixation method commonly employed worldwide for treating unstable fractures of the posterior pelvic ring is the percutaneous iliosacral screw technique. However, prolonged operation time and frequent fluoroscopies result in surgical risks. This study aimed to investigate whether a new triangulation method could reduce operative and fluoroscopy times and increase the accuracy of screw placement. METHODS: This study is a real-world retrospective cohort analysis that examined a patient cohort who underwent percutaneous iliosacral screw fixation between January 1, 2019 and December 31, 2022. Inclusion criteria were patients (1) diagnosed with posterior pelvic ring instability who underwent pelvic fracture closed reduction and percutaneous S1 transverse-penetrating iliosacral screw placement and (2) aged >18 years. Exclusion criteria were: (1) combined proximal femoral fractures, (2) severe soft tissue injury in the surgical area, (3) incomplete imaging data, and (4) declining to provide written informed consent by the patient. The patients were divided into 2 groups according to the screw insertion method: conventional and triangulation methods. Screw placement and fluoroscopy times recorded by the C-arm were compared between the 2 methods. The accuracy of screw placement was evaluated by Smith grading on postoperative CT. Normality tests were conducted to assess the distribution of the quantitative variables and the Chi-square test was used to compare the qualitative variables. RESULTS: The study included a total of 94 patients diagnosed with posterior pelvic ring instability, who underwent percutaneous iliosacral screw placement. The patients were divided into 2 groups: 46 patients treated with the conventional surgical method and 48 patients received the triangulation method. The operation time (61.13±9.69 vs. 35.77±6.27) min and fluoroscopy frequency times (52.15±9.29 vs. 24.40±4.04) of the triangulation method were significantly reduced (p<0.001). CONCLUSIONS The use of a triangular positioning technique for the surface positioning of percutaneous iliosacral screws could reduce the operative time and fluoroscopy frequency. And the screw placement accuracy using this new method was comparable to that using other conventional methods.
Humans ; Retrospective Studies ; Bone Screws ; Pelvic Bones/surgery* ; Male ; Female ; Fracture Fixation, Internal/methods* ; Fractures, Bone/surgery* ; Adult ; Middle Aged ; Fluoroscopy ; Aged ; Sacrum/surgery* ; Operative Time

This article aims to compare and analyze the biomechanical differences between wing-shaped titanium plates and traditional titanium plates in fixing acetabular anterior column and posterior hemi-transverse (ACPHT) fracture under multiple working conditions using the finite element method. Firstly, four sets of internal fixation models for acetabular ACPHT fractures were established, and the hip joint stress under standing, sitting, forward extension, and abduction conditions was calculated through analysis software. Then, the stress of screws and titanium plates, as well as the stress and displacement of the fracture end face, were analyzed. Research has found that when using wing-shaped titanium plates to fix acetabular ACPHT fractures, the peak stress of screws decreases under all working conditions, while the peak stress of wing-shaped titanium plates decreases under standing and sitting conditions and increases under forward and outward extension conditions. The relative displacement and mean stress of the fracture end face decrease under all working conditions, but the values are higher under forward and outward extension conditions. Wing-shaped titanium plates can reduce the probability of screw fatigue failure when fixing acetabular ACPHT fractures and can bear greater loads under forward and outward extension conditions, improving the mechanical stability of the pelvis. Moreover, the stress on the fracture end surface is more conducive to stimulating fracture healing and promoting bone tissue growth. However, premature forward and outward extension rehabilitation exercises should not be performed.
Titanium ; Bone Plates ; Humans ; Acetabulum/surgery* ; Fracture Fixation, Internal/methods* ; Biomechanical Phenomena ; Finite Element Analysis ; Bone Screws ; Fractures, Bone/surgery* ; Stress, Mechanical ; Working Conditions