OBJECTIVES: This study aims to analyze the biomechanics of three kinds of rigid internal fixation methods for condylar head fractures. METHODS: A three dimensional finite element model of the normal mandible was constructed. It was then used to prepare condylar head fracture finite element model and three kinds of rigid internal fixation finite element model (unilateral tension screw, bilateral tension screw, tension screw+titanium plate). The mechanical characteristics and changes of the mandible condyle under the same mechanical conditions were compared among the three different rigid internal fixation methods. RESULTS: The maximum equivalent stress and displacement of the non-free end of condyle under the rigid internal fixation method of unilateral tension screw were 71.03 MPa and 4.72 mm, respectively. The maximum equivalent stress and displacement of the free end of condyle were 78.45 MPa and 4.50 mm, respectively. The maximum stress of fracture suture was 3.27 MPa. The maximum equivalent stress and displacement of the non-free end of condyle under the rigid internal fixation method of bilateral tension screw were 70.52 MPa and 4.00 mm, respectively. The maximum equivalent stress and displacement of the free end of condyle were 72.49 MPa and 3.85 mm, respectively. The maximum stress of fracture suture was 2.33 MPa. The maximum equivalent stress and maximum displacement of the non-free end of condyle under the rigid internal fixation method of tension screw+titanium plate were 67.26 MPa and 2.66 mm, respectively. The maximum equivalent stress and maximum displacement of the free end of condyle were 69.66 MPa and 2.50 mm, respectively. The maximum stress of fracture suture was 2.18 MPa. CONCLUSIONS The tension screw+titanium plate rigid internal fixation method is the most conducive to biomechanical distribution for condylar head fractures.
Fracture Fixation, Internal/instrumentation* ; Mandibular Condyle/surgery* ; Biomechanical Phenomena ; Bone Screws ; Finite Element Analysis ; Humans ; Mandibular Fractures/surgery* ; Bone Plates ; Titanium ; Stress, Mechanical

OBJECTIVES: This study investigates independent risk factors for postoperative internal fixation device infection in patients with maxillofacial fractures and proposes an early warning model based on the synthetic minority over-sampling technique (SMOTE) algorithm. METHODS: A total of 1 104 patients who underwent surgical treatment for maxillofacial fractures at Oral and Maxillofacial Surgery Department, Affiliated Hospital of Nantong University from January 2021 to December 2024 were retrospectively analyzed. The patients were divided into two groups based on the presence of postoperative internal fixation device infection: the infection group (27 cases) and non-infection group (1 077 cases). Clinical data from both groups were collected and subjected to statistical analysis. Univariate and binary Logistic regression analysis were used to identify risk factors for postoperative internal fixation device infection in maxillofacial fractures. Subsequently, a Logistic regression model was established, and the dataset was improved based on the SMOTE algorithm to construct an early warning model with the improved dataset. The prediction performance of the models was compared and validated. RESULTS: Among the 1 104 patients who underwent surgical treatment for maxillofacial fractures, 27 cases of postoperative internal fixation device infections were identified, corresponding to an infection rate of 2.45% (27/1 104). Age, diabetes history, fracture severity, and oral hygiene status were all identified as risk factors for postoperative internal fixation device infections in maxillofacial fractures (all P<0.05). The prediction model based on the original data (P1). The prediction model based on the SMOTE algorithm (P2). Receiver operating characteristic (ROC) curve analysis shows that the area under curve (AUC) for the P2 model was 0.882, the P1 model was 0.861, indicating the superior predictive performance of the P2 model. The DeLong test results show that the difference in AUC between the two models was statistically significant (P<0.05). CONCLUSIONS Age, diabetes history, postoperative fracture severity, and oral hygiene status are all risk factors for infections associated with internal fixation devices after maxillofacial fracture surgery. The proposed early warning model demonstrated good predictive performance. Medical professionals can utilize this model to effectively intervene and anticipate infections related to internal fixation devices after maxillofacial fracture surgery.
Humans ; Algorithms ; Retrospective Studies ; Male ; Female ; Fracture Fixation, Internal/instrumentation* ; Risk Factors ; Middle Aged ; Adult ; Logistic Models ; Surgical Wound Infection/epidemiology* ; Aged ; Internal Fixators/adverse effects* ; Maxillofacial Injuries/surgery* ; Adolescent

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 iliac oblique 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 iliac oblique view and iliac tangential view. 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%. CONCLUSION Utilizing a CT-defined safe distance range from the screw trajectory to the greater sciatic notch, and adhering to this range under iliac oblique view combined with iliac tangential view fluoroscopy, enables the accurate and precise placement of LC-Ⅱ screws.
Humans ; Male ; Female ; Middle Aged ; Bone Screws ; Adult ; Tomography, X-Ray Computed/methods* ; Aged ; Ilium/surgery* ; Pelvic Bones/diagnostic imaging* ; Fracture Fixation, Internal/instrumentation* ; Retrospective Studies ; Fluoroscopy ; Fractures, Bone/diagnostic imaging* ; Young Adult

OBJECTIVE: To compare the effectiveness of percutaneous short-segment injured vertebra pedicle screw fixation combined with bone grafting versus percutaneous short-segment injured vertebra pedicle screw fixation alone for the treatment of thoracolumbar fractures. METHODS: The clinical data of 54 patients with single-level thoracolumbar fractures who met the selection criteria between January 2023 and February 2024 were retrospectively analysed. Based on whether bone grafting was performed on the injured vertebra, the patients were divided into a control group (28 cases, percutaneous short-segment injured vertebra pedicle screw fixation alone) and a study group (26 cases, percutaneous short-segment injured vertebra pedicle screw fixation combined with bone grafting using a self-made minimally invasive bone grafting funnel). No significant difference was observed between the two groups ( P>0.05) in baseline data, including age, gender, surgical segment, cause of injury, AO classification, and preoperative anterior-vertebral height compression ratio, mid-vertebral height compression ratio, Cobb angle, visual analogue scale (VAS) score, and Oswestry Disability Index (ODI). The operation time, intraoperative blood loss, fracture healing status, removal time of internal fixator, and complications were recorded and compared between the two groups. Effectiveness was assessed using anterior-vertebral height compression ratio, mid-vertebral height compression ratio, Cobb angle, VAS scores, and ODI taken preoperatively, at 1 week postoperatively, and at last follow-up. RESULTS: All patients in both groups successfully underwent surgery. The operation time and intraoperative blood loss in the control group were significantly less than those in the study group ( P<0.05). No significant difference was observed in the follow-up time between the study group [(14.46±2.00) months] and control group [(14.36±1.83) months] ( P>0.05). The fracture healing time of the study group was significantly shorter than that of the control group ( P<0.05). One patient in the study group was found to have bilateral titanium rod breakage by X-ray reexamination at 8 months after operation, and there was no subsequent vertebral height collapse occurred, and the internal fixator was removed following complete fracture healing. The other patients had no complication such as spinal cord injury, internal fixator loosening and breakage. There was no significant difference in the removal time of internal fixator between the two groups ( P<0.05). The anterior-vertebral height compression ratio, mid-vertebral height compression ratio, Cobb angle, VAS score, and ODI significantly improved in both groups at 1 week after operation and at last follow-up ( P<0.05). Among them, the VAS score, and ODI further improved at last follow-up when compared with at 1 week after operation, Cobb angle lost a little at 1 week after operation, while anterior-vertebral height compression ratio and mid-vertebral height compression ratio slightly increased when compared with 1 week after operation, and the differences were significant ( P<0.05). There was no significant difference between the two groups in Cobb angle at last follow-up, VAS score and ODI at 1 week after operation ( P>0.05), while the other indicators in the study group were significantly better than those in the control group at all time points ( P<0.05). CONCLUSION Compared to percutaneous short-segment injured vertebra pedicle screw fixation alone, the technique combined with intravertebral bone grafting can shorten fracture healing time, effectively restore and maintain vertebral body height, correct kyphotic deformity, and improve clinical outcomes for patients with thoracolumbar fractures.
Humans ; Thoracic Vertebrae/surgery* ; Pedicle Screws ; Lumbar Vertebrae/surgery* ; Spinal Fractures/surgery* ; Bone Transplantation/methods* ; Fracture Fixation, Internal/instrumentation* ; Male ; Female ; Retrospective Studies ; Adult ; Middle Aged ; Treatment Outcome ; Minimally Invasive Surgical Procedures/methods* ; Operative Time ; Aged

OBJECTIVE: To compare the effectiveness of using a composite loop plate to reconstruct the coracoclavicular ligament around the coracoid process and using a clavicular hook plate for fixation in treatment of Rockwood type Ⅲ acute acromioclavicular joint dislocation. METHODS: A retrospective analysis was conducted on the clinical data of 60 patients with Rockwood type Ⅲ acute acromioclavicular joint dislocation who were admitted between June 2022 and September 2023 and met the selection criteria. Among them, 30 patients were treated with the composite loop plate to reconstruct the coracoclavicular ligament around the coracoid process (loop plate group) and 30 with clavicular hook plate fixation (hook plate group). There was no significant difference in baseline data between the two groups ( P>0.05), including gender, age, injured side, cause of injury, disease duration, preoperative visual analogue scale (VAS) score for pain, and Constant-Murley score. The incision length, operation time, length of hospital stay, and the occurrence of complications during follow-up were recorded. The Constant-Murley score and VAS score were used to evaluate shoulder joint function and pain, and the differences (change values) of the indicators between before operation and at 6 months after operation were calculated for inter-group comparison. In the loop plate group, the coracoclavicular distance (CCD) on the anteroposterior X-ray films of the acromioclavicular joint was measured at 1 day and 6 months after operation to assess the loss of acromioclavicular joint reduction. RESULTS: The incision length of the loop plate group was significantly shorter than that of the hook plate group ( P<0.05). There was no significant difference in the operation time and the length of hospital stay between the two groups ( P>0.05). All incisions healed by first intention after operation. All patients were followed up 12-18 months (mean, 16.3 months). There was no significant difference in the follow-up time between groups ( P>0.05). The Constant-Murley scores and VAS scores of both groups significantly improved at 6 months after operation when compared with those before operation ( P<0.05); the differences in the change values of the two indicators between groups were significant ( P<0.05). The CCD of the loop plate group were (10.40±0.83) mm at 1 day and (10.70±0.68) mm at 6 months and no repositioning loss was observed. Three cases in the hook plate group had residual shoulder joint pain after operation. The difference in the accidence of complications between groups was not significant ( P>0.05). CONCLUSION For Rockwood type Ⅲ acute acromioclavicular joint dislocation, compared with the clavicular hook plate fixation, the composite loop plate for reconstructing the coracoclavicular ligament around the coracoid process has the advantages of simple operation, safety, minimally invasive, good functional recovery, and fewer complications. Moreover, it avoids the need for a second surgery to remove the internal fixation device, and the patient acceptance and satisfaction are higher.
Humans ; Acromioclavicular Joint/surgery* ; Bone Plates ; Male ; Retrospective Studies ; Female ; Adult ; Ligaments, Articular/injuries* ; Joint Dislocations/surgery* ; Coracoid Process/injuries* ; Treatment Outcome ; Middle Aged ; Plastic Surgery Procedures/instrumentation* ; Fracture Fixation, Internal/instrumentation* ; Young Adult ; Clavicle/surgery*

OBJECTIVE: To investigate the effectiveness of TiRobot-assisted minimally invasive treatment for fragility fractures of the pelvis (FFP) in elderly patients. METHODS: A retrospective analysis was conducted on the clinical data of 176 patients with FFP who were admitted between July 2018 and July 2024 and met the selection criteria. Among them, 95 patients underwent TiRobot-assisted closed reduction and minimally invasive cannulated screw fixation (robot group), while 81 patients underwent traditional open reduction and plate screw fixation (control group). There was no significant difference in baseline data such as gender, age, fracture classification, disease duration, and preoperative visual analogue scale (VAS) pain scores between the two groups ( P>0.05). The following parameters were recorded and compared between the two groups, including operation time, intraoperative blood loss, intraoperative transfusion rate, volume of intraoperative blood transfusion, maximum incision length, hospital stay, maximum residual displacement, reduction quality, fracture healing time, incidence of complications, VAS scores, Majeed pelvic function scores, and functional grading. RESULTS: All surgeries in both groups successfully completed. The robot group exhibited significantly shorter operation time, reduced intraoperative blood loss, lower intraoperative transfusion rate, smaller volume of intraoperative blood transfusion, shorter maximum incision length, and shorter hospital stay compared to the control group ( P<0.05). In the robot group, a total of 14 INFIX internal fixation frames and 280 cannulated screws were implanted, among which 250 screws were rated as excellent, 17 as good, and 13 as poor, resulting in a screw placement excellent and good rate of 95.36%. Radiological review revealed that the excellent and good rate of reduction quality was in 91.58% (87/95) in the robot group and 81.48% (66/81) in the control group, with no significant difference in postoperative maximum residual fracture displacement or reduction quality between the two groups (P>0.05). All patients in both groups were followed up 12-66 months, with an average of 28.9 months, and there was no significant difference in follow-up time between the two groups ( P>0.05). The fracture healing time in the robot group was significantly shorter than that in the control group ( P<0.05). At last follow-up, both groups showed significant improvement in VAS scores compared to preoperative values ( P<0.05); the change values of VAS scores, Majeed scores, and the excellent and good rate of Majeed pelvic function were significantly higher in the robot group than in the control group ( P<0.05). Regarding postoperative complications, there was no significant difference between the two groups in terms of gait changes, secondary surgeries, heterotopic ossification, incision infections, walking difficulties, internal fixation failure, or mortality rates ( P>0.05); however, the incidence of delayed wound healing was significantly lower in the robot group than in the control group ( P<0.05). CONCLUSION TiRobot-assisted minimally invasive treatment of elderly FFP is superior to traditional open reduction and internal fixation in terms of surgical trauma control, postoperative rehabilitation speed, and functional recovery.
Humans ; Male ; Retrospective Studies ; Female ; Minimally Invasive Surgical Procedures/instrumentation* ; Fracture Fixation, Internal/instrumentation* ; Pelvic Bones/surgery* ; Aged ; Bone Screws ; Bone Plates ; Robotic Surgical Procedures/methods* ; Aged, 80 and over ; Treatment Outcome ; Osteoporotic Fractures/surgery* ; Operative Time ; Blood Loss, Surgical ; Fracture Healing ; Fractures, Bone/surgery*

OBJECTIVE: To evaluate the safety and effectiveness of reducing posterior malleolar fractures via the modified Rammelt transfibular approach. METHODS: A retrospective analysis was conducted on 26 patients with ankle fractures who met the selection criteria and were admitted between September 2023 and May 2024. There were 13 males and 13 females, aged from 14 to 59 years (median, 43.5 years). Causes of injury included traffic accident (1 case), falls (7 cases), and sprains (18 cases). Time from injury to operation ranged from 1 to 13 days (mean, 3.9 days). According to the Lauge-Hansen classification, there were 5 supination-external rotation type Ⅲ fractures and 21 supination-external rotation type Ⅳ fractures. According to the Bartoníček classification for posterior malleolar fractures, there were 12 type Ⅱ fractures, 10 type Ⅲ fractures, and 4 type Ⅳ fractures. During operation, the fracture was exposed via the modified Rammelt transfibular approach; then, the fracture reduction was achieved under direct vision using techniques such as towel clip traction, posterolateral compression, and lifting with a posterior transverse periosteal elevator; finally, the fracture was fixed using anteroposterior cannulated screws or Kirschner wires. The incision healing was observed after operation. At 4 months after operation, X-ray film and CT were reviewed to evaluate the quality of fracture reduction. The medial clear space, tibiofibular clear space, and the anterior/posterior tibiofibular syndesmotic distances were measured. At last follow-up, the ankle function was assessed using the American Orthopaedic Foot & Ankle Society (AOFAS) score and the range of motion. RESULTS: The marginal necrosis occurred in 2 lateral malleolar incisions, and superficial infection occurred in 1 lateral malleolar incision; the remaining incisions healed by first intention. All 26 patients were followed up 13-21 months (mean, 15.6 months). X-ray films showed that fractures in 25 patients achieved clinical union within 3-8 months (mean, 5.4 months); 1 case had delayed union of the lateral malleolus. At 4 months after operation, no significant difference was found between the injured and healthy sides in the medial clear space, tibiofibular clear space, or the anterior/posterior tibiofibular syndesmotic distances ( P>0.05). No malreduction of the posterior malleolus or the tibiofibular syndesmosis occurred. At last follow-up, the AOFAS score ranged from 80 to 100 (mean, 91.9). The range of motion ranged from 17° to 22° (mean, 21.0°) in active ankle dorsiflexion and from 40° to 49° (mean, 44.6°) in plantar flexion. Internal fixator was removed in 12 patients at 1 year after operation, with no ankle instability occurring. Ankle joint degeneration was observed in 1 patient at last follow-up. CONCLUSION The modified Rammelt transfibular approach is a safe and reliable technique. It enables precise reduction under direct vision, improves the quality of reduction for the distal tibial articular surface and the tibiofibular syndesmosis, and provides satisfactory ankle functional recovery in short-term follow-up.
Humans ; Male ; Female ; Adult ; Ankle Fractures/diagnostic imaging* ; Middle Aged ; Retrospective Studies ; Fracture Fixation, Internal/instrumentation* ; Adolescent ; Treatment Outcome ; Young Adult ; Bone Screws ; Ankle Joint/surgery* ; Fibula/surgery* ; Range of Motion, Articular

OBJECTIVE: To review the main fixation methods for proximal tibial extra-articular fractures based on clinical and biomechanical results, and to provide evidence for clinical application. METHODS: Extensive related literature at home and abroad was conducted in recent years, and external fixation systems such as external fixation braces and external locking plates, as well as internal fixation systems such as plates and intramedullary nails, were systematically reviewed regarding their application indications, clinical efficacy, and biomechanical results in proximal tibial extra-articular fractures. RESULTS: External fixation systems have advantages in fractures with open or severe soft tissue injury, facilitating wound management and maintaining stability of the fracture site to some extent. However, in proximal tibial extra-articular fractures with good soft tissue conditions, internal fixation systems such as plates and intramedullary nails are still the first choice. Some studies have found that intramedullary nails allow patients to bear weight early, with shorter fracture healing time and higher rate of malunion, while other studies have found that both intramedullary nails and plates have similar clinical efficacy and can achieve satisfactory treatment results. CONCLUSION The choice of fixation method for proximal tibial extra-articular fractures depends not only on the type of fracture, but also on the surgeon's habits and operational skills. Larger-scale studies are still needed to clarify the advantages and disadvantages of intramedullary nails and locking plates in the treatment of proximal tibial extra-articular fractures.
Humans ; Tibial Fractures/surgery* ; Bone Plates ; Fracture Fixation, Intramedullary/instrumentation* ; Fracture Fixation, Internal/instrumentation* ; Fracture Healing ; External Fixators ; Bone Nails ; Fracture Fixation/instrumentation* ; Treatment Outcome ; Biomechanical Phenomena

OBJECTIVE: To investigate effectiveness of the bridge combined fixation system (BCFS) for Bado typeⅠchronic Monteggia fractures (CMF) in children. METHODS: A clinical data of 8 children with Bado type ⅠCMF, who were treated with the BCFS between November 2023 and February 2025, was retrospectively analyzed. There were 6 boys and 2 girls, with a mean age of 7.0 years (range, 4-12 years). The time from injury to operation ranged from 29 to 370 days (median, 68.5 days). Preoperative elbow range of motion was (111.3±17.9)° in flexion, (13.1±13.9)° in extension, (71.9±14.6)° in pronation, and (75.6±13.5)° in supination. Fracture healing time and postoperative complications were observed, and clinical outcomes were evaluated using the Mayo elbow performance score. RESULTS: All incisions healed by primary intention without infection, non-healing of the incision, or iatrogenic nerve injury. All children were followed up 4-18 months (mean, 10.3 months). At last follow-up, the elbow range of motion significantly improved to (142.5±2.7)° in flexion, (2.5±2.7)° in extension, (87.5±2.7)° in pronation, and (88.8±2.3)° in supination ( P<0.05). According to the postoperative Mayo elbow performance score, all cases were rated as excellent. Radiographic review showed no radial head dislocation, nonunion at the ulnar osteotomy site, or elbow stiffness, and no breakage of the BCFS or screw loosening. The fracture healing time ranged from 3 to 6 months, with a median of 4 months. CONCLUSION The BCFS was confirmed to be effective in the treatment of pediatric Bado type Ⅰ CMF, with good restoration of elbow function and the advantage of avoiding secondary implant removal surgery.
Humans ; Child ; Monteggia's Fracture/surgery* ; Male ; Female ; Child, Preschool ; Range of Motion, Articular ; Retrospective Studies ; Fracture Fixation, Internal/instrumentation* ; Elbow Joint/physiopathology* ; Bone Plates ; Treatment Outcome ; Fracture Healing ; Bone Screws ; Elbow Injuries

OBJECTIVE: To evaluate the effectiveness of suture anchors combined with headless compression screw fixation in treating inferior pole patellar fractures. METHODS: A retrospective analysis was conducted on 36 patients with inferior pole patellar fractures, who were admitted between January 2018 and October 2024 and met the selective criteria. There were 15 males and 21 females with a mean age of 52.3 years (range, 23-81 years). The fracture were reduced and fixed using suture anchors combined with headless compression screws. The operation time, intraoperative blood loss, and the length of hospital stay were recorded. Functional recovery was assessed using knee range of motion (ROM), Hospital for Special Surgery (HSS) knee score, and Böstman patellar fracture efficacy score. RESULTS: The operation time ranged from 10 to 100 minutes, with an average of 57.6 minutes. The intraoperative blood loss was 10 to 120 mL, with an average of 73.3 mL. The length of hospital stay was 5 to 10 days, with an average of 6.3 days. All incisions healed by first intention. All 36 patients were followed up 18-24 months (mean, 20.6 months). Postoperative X-ray films indicated that the fractures had healed; no screw breakage, anchor loosening, or implant foreign body rejection reactions occurred during follow-up. At last follow-up, the ROM of the affected knee joint was (136.0±2.3)°, and there was no significant difference when compared with the healthy side (136.6±2.3)° ( t=-1.944, P=0.060). The HSS score of the affected knee joint was 96-100 (mean, 99.1), and all cases were rated as excellent. The Böstman patellar fracture efficacy score was 27-30 (mean, 29.1), and 35 cases were rated as excellent and 1 as good. CONCLUSION The suture anchors combined with headless compression screws technique provides reliable fixation for inferior pole patellar fractures. This method combines surgical simplicity with excellent functional outcomes.
Humans ; Male ; Female ; Middle Aged ; Bone Screws ; Aged ; Retrospective Studies ; Patella/surgery* ; Fracture Fixation, Internal/instrumentation* ; Adult ; Aged, 80 and over ; Suture Anchors ; Fractures, Bone/surgery* ; Range of Motion, Articular ; Treatment Outcome ; Young Adult ; Operative Time ; Length of Stay