OBJECTIVE: To compare the biomechanical properties of four internal fixation methods in a lower cervical spine injury model using the finite element method. METHODS: Cervical CT data of a 28-year-old healthy adult male were utilized to establish a finite element model of the normal cervical spine and a lower cervical spine three-column injury model. Four internal fixation methods were then applied to the three-column injury model, resulting in four groups:Group A, anterior cervical locked-plate(ACLP) fixation system model(anterior approach);Group B, posterior cervical pedicle screw fixation model (posterior approach);Group C, combined anterior and posterior cervical pedicle screw fixation model; Group D, Novel composite anterior cervical internal fixation model. A 75 N axial compressive load and a 1.0 N·m pure moment were applied to the upper surface of the cervical spine model to simulate flexion, extension, rotation, and lateral bending movements. The intervertebral range of motion(ROM) and stress distribution of the internal fixators under different motion conditions were compared across all models. RESULTS: Compared with the normal model, the reductions in overall intervertebral ROM for each group under flexion, extension, rotation, and lateral bending were as follows:Group A, 24.04°, 23.12°, 6.24°, and 9.06°;Group B, 24.42°, 24.34°, 6.48°, and 9.20°;Group C, 25.43°, 25.29°, 7.17°, and 9.57°;Group D, 24.75°, 25.5°, 6.71°, and 9.12°. The peak stress values of the internal fixators in each group were:Group A, 53.9 MPa, 79.9 MPa, 61.4 MPa, and 80.3 MPa;Group B, 218.3 MPa, 105.4 MPa, 206.6 MPa, and 186.8 MPa;Group C, 40.8 MPa, 97.2 MPa, 47.1 MPa, and 39.4 MPa;Group D, 93.0 MPa, 144.0 MPa, 64.8 MPa, and 106.3 MPa. CONCLUSION The biomechanical properties of the novel composite anterior cervical internal fixation method are similar to those of the combined anterior-posterior fixation method, and superior to both the anterior cervical ACLP plate-screw fixation and posterior cervical pedicle screw fixation methods.
Humans ; Finite Element Analysis ; Cervical Vertebrae/physiopathology* ; Male ; Biomechanical Phenomena ; Adult ; Fracture Fixation, Internal/methods* ; Range of Motion, Articular

PURPOSE: To assess the relationship between dislocation and functional outcomes in supination-external rotation (SER) ankle fractures. METHODS: A retrospective case series study was performed on patients with ankle fractures treated surgically at a large trauma center from January 2015 to December 2021. The inclusion criteria were young and middle-aged patients of 18 - 65 years with SER ankle fractures that can be classified by Lauge-Hansen classification and underwent surgery at our trauma center. Exclusion criteria were serious life-threatening diseases, open fractures, fractures delayed for more than 3 weeks, fracture sites ≥ 2, etc. Then patients were divided into dislocation and no-dislocation groups. Patient demographics, injury characteristics, surgery-related outcomes, and postoperative functional outcomes were collected and analyzed. The functional outcomes of SER ankle fractures were assessed postoperatively at 1-year face-to-face follow-up using the foot and ankle outcome score (FAOS) and American Orthopedic Foot and Ankle Society ankle hindfoot score and by 2 experienced orthopedic physicians. Relevant data were analyzed using SPSS version 22.0 by Chi-square or t-test. RESULTS: During the study period, there were 371 ankle fractures. Among them, 190 (51.2%) were SER patterns with 69 (36.3%) combined with dislocations. Compared with the no-dislocation group, the dislocation group showed no statistically significant differences in gender, age composition, fracture type, diabetes, or smoking history, preoperative waiting time, operation time, and length of hospital stay (all p > 0.05), but a significantly higher Lauge-Hansen injury grade (p < 0.001) and syndesmotic screw fixation rate (p = 0.033). Moreover, the functional recovery was poorer, revealing a significantly lower FAOS in the sport/rec scale (p < 0.001). Subgroup analysis showed that among SER IV ankle fracture patients, FAOS was much lower in pain (p = 0.042) and sport/rec scales (p < 0.001) for those with dislocations. American Orthopedic Foot and Ankle Society ankle hindfoot score revealed no significant difference between dislocation and no-dislocation patients. CONCLUSION Dislocation in SER ankle fractures suggests more severe injury and negatively affects functional recovery, mainly manifested as more pain and poorer motor function, especially in SER IV ankle cases.
Humans ; Ankle Fractures/physiopathology* ; Male ; Female ; Retrospective Studies ; Adult ; Middle Aged ; Supination ; Aged ; Young Adult ; Rotation ; Joint Dislocations/surgery* ; Fracture Fixation, Internal/methods* ; Adolescent ; Recovery of Function ; Treatment Outcome

PURPOSE: Lateral compression (LC) injuries account for more than two-thirds of all pelvic fractures. The goal of surgical treatment is to provide adequate stability and early mobilization. The consensus on posterior fixation of such injuries is strong in the literature; however, the necessity of anterior ring fixation is not clear. Therefore, this study was formulated to determine the practicability of posterior-only fixation in LC injuries. METHODS: Between March 2015 and May 2020, all patients with LC type pelvic ring fractures who were admitted and operated upon in a single level 1 trauma center were included in this cross-sectional observational study. Demographic data, co-morbidities, treatment, types of surgical fixation, concomitant injuries and surgeries, surgical complications, length of hospital stay, injury to weight bearing duration, and follow-up period were documented. Functional outcome and quality of life were assessed using Majeed score and SF-36 questionnaire. Non-normally distributed data were presented as median (Q₁, Q₃) and normally distributed data were presented as mean ± standard deviation (SD). Spearman's rank correlation coefficient was used for correlation analysis. RESULTS: A total of 25 patients were included, with a mean age of 29.8 years. All patients were managed operatively with posterior-only fixation. The median Majeed score was 90 (76, 95). The median physical component summary score was 69.37 (38.75, 85.62). The median mental component summary score was 63.95 (39.25, 87.87). There was no significant difference compared to population norms of both physical component summary and mental component summary. Injury to weight bearing time correlated significantly (p = 0.002) with Majeed score as well as SF-36 score (p = 0.044). No other variable had a significant association with outcomes. CONCLUSION Posterior-only fixation is sufficient for fixing LC injuries with up to 80% of cases having good to excellent functional outcomes. However, comparative studies with larger sample sizes are needed for further validation.
Humans ; Male ; Female ; Adult ; Cross-Sectional Studies ; Pelvic Bones/surgery* ; Fractures, Bone/surgery* ; Fracture Fixation, Internal/methods* ; Middle Aged ; Young Adult ; Quality of Life ; Adolescent ; Length of Stay

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: 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

OBJECTIVES: To assess the biomechanical performance of a novel bridging plate for treating Rockwood III acromioclavicular joint dislocation. METHODS: A novel bridging plate structure was designed based on CT data from a patient with Rockwood type III acromioclavicular joint dislocation, and a finite element model of the bridging plate-acromioclavicular joint interaction was constructed. The stress and deformation characteristics and biomechanical compatibility of the plate under post-reduction, normal loading, and impact loading conditions were analyzed to evaluate its fixation mechanism and clinical advantages. RESULTS: The stiffness of the bridging system was 27.78 N/mm, close to that of acromioclavicular joint ligaments (26.05 N/mm) and meeting the requirements for flexible deformation. Under normal loading, the maximum stress in the bridging system was 88.29 MPa to sustain physiological activities; under impact loading, the maximum stress reached 480 MPa, and the cable underwent plastic deformation to dissipate energy and effectively buffer local stress concentrations, thereby reducing the risk of rigid bone fractures. The high-stress regions in the bone primarily occurred at the edges of the C1-C4 screw holes. The maximum bone stress was 0.762 MPa under normal loading and 5.963 MPa under impact loading, accounting for 2.86% and 1.66% of the corresponding bolt stresses, respectively. CONCLUSIONS The novel bridging plate is better adapted to biomechanical characteristics of the acromioclavicular joint compared to traditional internal fixation. This fixation system provides sufficient stability while allowing physiological micromotion to facilitate postoperative rehabilitation. Significant flexible deformation can occur at the connection between the fixation ring and the cable, and brittle materials should not be used in this region. The issue of stress concentration at the C1-C4 screw holes requires special attention in its clinical application.
Acromioclavicular Joint/surgery* ; Humans ; Bone Plates ; Biomechanical Phenomena ; Finite Element Analysis ; Joint Dislocations/surgery* ; Fracture Fixation, Internal/methods*

OBJECTIVE: To explore effectiveness of TiRobot-assisted screw implantation in the treatment of coracoid process fractures of the scapula. METHODS: A retrospective analysis was conducted on the clinical data from 24 patients with coracoid process fractures of the scapula admitted between September 2019 and January 2024 and met selection criteria. Among them, 12 patients underwent TiRobot-assisted screw implantation (robot group) and 12 underwent manual screw implantation (control group) during internal fixation. There was no significant difference ( P>0.05) in baseline data such as gender, age, body mass index, disease duration, cause of injury, coracoid process fracture classification, and proportion of patients with associated injuries between the two groups. The incision length, operation time, intraoperative blood loss, hospital stay, accuracy of screw placement, coracoid process fracture healing time, and complications were recorded and compared, as well as pain visual analogue scale (VAS) score, and Constant-Murley score at last follow-up. RESULTS: The intraoperative blood loss and incision length in the robot group were significantly lower than those in the control group ( P<0.05); however, there was no significant difference in operation time and hospital stay between the two groups ( P>0.05). All patients were followed up 8-27 months (mean, 17.5 months), and the difference in follow-up time between the two groups was not significant ( P>0.05). At last follow-up, the VAS score for shoulder pain in the robot group was signifncatly lower compared to the control group, and the Constant-Murley score was significantly higher ( P<0.05). In the robot group, 16 screws were implanted intraoperatively, while 13 screws were implanted in the control group. Radiographic re-evaluation showed that the excellent and good rate of screw implantation was higher in the robot group (93.8%, 15/16) than in the control group (61.5%, 8/13), but the difference in the precision of screw implantation between the two groups was not significant ( P>0.05). Four patients in the robot group and 1 in the control group achieved double screws fixation; however, the difference in achieving double screws fixation between the two groups was not significant ( P>0.05). All fractures healed in both groups with 1 case of malunion in the control group. There was no significant difference in healing time between the two groups ( P>0.05). During follow-up, 1 patient in the control group experienced screw loosening and displacement. There was no significant difference in the incidence of screw loosening and fracture malunion between the two groups ( P>0.05). CONCLUSION Compared with manual screw implantation, TiRobot-assisted minimally invasive treatment of coracoid process fractures of the scapula can reduce intraoperative blood loss, shorten incision length, alleviate pain, and obtain better promote shoulder joint functional recovery.
Humans ; Male ; Female ; Retrospective Studies ; Fracture Fixation, Internal/instrumentation* ; Minimally Invasive Surgical Procedures/instrumentation* ; Adult ; Middle Aged ; Fractures, Bone/surgery* ; Bone Screws ; Coracoid Process/surgery* ; Robotic Surgical Procedures/methods* ; Scapula/surgery* ; Treatment Outcome ; Operative Time ; Young Adult ; Length of Stay ; Blood Loss, Surgical

OBJECTIVE: To compare the effectiveness of ultrasound-guided closed reduction with Kirschner wire fixation and open reduction with Kirschner wire fixation in the treatment of humeral lateral condyle fracture (HLCF) in children. METHODS: A clinical data of 53 children with HLCF admitted between May 2020 and April 2023 and met selective criteria was retrospectively analyzed. Of these, 25 cases were managed with closed reduction and Kirschner wire fixation under ultrasound guidance (closed group), while 28 cases underwent open reduction and Kirschner wire fixation (open group). There was no significant difference between the two groups in terms of gender, age, cause of injury, fracture side, fracture classification, and time from injury to operation ( P>0.05). The following variables were recorded and compared between the two groups: operation time, intraoperative fluoroscopy frequency, fracture healing time, incidence of complications, and the Flynn elbow function score at last follow-up. RESULTS: In the closed group, the fractures were successfully reduced under ultrasound guidance, with no nerve damage reported in either group. The operation time and intraoperative fluoroscopy frequency were significantly less in the closed group than in the open group ( P<0.05). One case of infection (Kirschner wire irritation) was observed in the closed group, while 3 cases in the open group (2 of Kirschner wire irritation and 1 of incision infection). However, the difference in the incidence of infection between the two groups was not significant ( P>0.05). All patients in both groups were followed up 6-18 months (mean, 10.2 months). X-ray examinations confirmed that fractures had healed in both groups, with no significant difference in healing time ( P>0.05). During follow-up, 5 cases of lateral humeral process formation were observed in the closed group, compared to 12 cases in the open group, although this difference was not significant ( P>0.05). At last follow-up, the excellent and good rate of elbow joint function was evaluated as 96.0% (24/25) in the closed group and 92.9% (26/28) in the open group according to the Flynn scoring criteria, with no significant difference between the two groups ( P>0.05). Both groups showed no occurrence of ossifying myositis or elbow internal/external rotation. CONCLUSION The effectiveness of ultrasound-guided closed reduction and Kirschner wire fixation in the treatment of HLCF in children is comparable to open reduction and Kirschner wire fixation, but the former can reduce operation time and intraoperative fluoroscopy frequency, and obtain lower the incidence of complications.
Humans ; Humeral Fractures/diagnostic imaging* ; Bone Wires ; Male ; Female ; Child ; Retrospective Studies ; Fracture Fixation, Internal/instrumentation* ; Treatment Outcome ; Child, Preschool ; Open Fracture Reduction/methods* ; Fracture Healing ; Elbow Joint/surgery* ; Adolescent ; Closed Fracture Reduction/methods* ; Fluoroscopy ; Operative Time

OBJECTIVE: To investigate the effectiveness of posterior minimally invasive approach in the treatment of posterior wall acetabular fractures. METHODS: The clinical data of 17 patients with posterior wall acetabular fractures treated with posterior minimally invasive approach between March 2019 and June 2023 were retrospectively analyzed. There were 14 males and 3 females with an average age of 41 years ranging from 28 to 57 years. The causes of injury were traffic accident in 12 cases and falling from height in 5 cases. There were 3 cases complicated with posterior hip dislocation and 2 cases complicated with sciatic nerve injury. According to AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 11 cases of type A1.1 and 6 cases of type A1.2. The time from injury to operation was 5-8 days, with an average of 6.2 days. The incision length, intraoperative blood loss, and operation time were recorded. The quality of posterior wall fracture reduction were evaluated by Matta criteria, and hip function were evaluated by modified Merle d'Aubign-Postel score criteria at 6 months after operation and last follow-up. RESULTS: The operation was successfully completed in 17 cases. The length of incision ranged from 7 to 9 cm, with an average of 8.3 cm, and all incisions healed by first intention. The intraoperative blood loss ranged from 200 to 350 mL, with an average of 281 mL. The operation time ranged from 45 to 70 minutes, with an average of 57 minutes. Two patients had sciatic nerve injury before operation, and the sciatic nerve function recovered completely at 3 months after operation; the other 15 patients had no symptoms of sciatic nerve injury after operation. All the 17 patients were followed up 14-27 months, with an average of 19.5 months. At 1 week after operation, according to the Matta criteria, anatomical reduction was achieved in 12 cases and satisfactory reduction in 5 cases, with a satisfaction rate of 100%. According to the modified Merle d'Aubign-Postel scoring system, the hip function score was 13-18 (mean, 16.1) at 6 months after operation. Among them, 5 cases were excellent, 9 were good, and 3 were fair, with an excellent and good rate of 82.4%. At last follow-up, the hip function score was 7-18 (mean, 13.7), of which 3 cases were excellent, 9 were good, 3 were fair, and 2 were poor, with an excellent and good rate of 70.6%. During the follow-up, there was no infection, failure of internal fixation, and femoral head necrosis, and heterotopic ossification occurred in 2 cases. CONCLUSION The posterior minimally invasive approach has the advantages of less trauma, shorter operation time, less blood loss, without cutting off the external rotator muscle. Exposure through the gluteus medius-piriformis space and piriformis-supercilium space can provide sufficient safe exposure for the posterior wall acetabulum fracture, which is a reliable alternative approach for the posterior acetabular fracture.
Humans ; Acetabulum/surgery* ; Male ; Female ; Adult ; Middle Aged ; Minimally Invasive Surgical Procedures/methods* ; Retrospective Studies ; Fracture Fixation, Internal/instrumentation* ; Fractures, Bone/diagnostic imaging* ; Treatment Outcome ; Operative Time