OBJECTIVE: To investigate short-term effectiveness of using expert adolescent lateral femoral nail (EALFN) in treating femoral shaft fractures in older children and adolescents. METHODS: A retrospective analysis was conducted on the clinical data of 17 patients with femoral shaft fractures who met the inclusion criteria and were admitted between July 2020 and June 2024. All fractures were fixed with EALFN after reduction. There were 11 males and 6 females, with a mean age of 13.3 years (range, 11-16 years). The average body weight was 51.2 kg (range, 40-84 kg), and the average height was 162.1 cm (range, 150-172 cm). The causes of injury included traffic accidents ( n=9), falling from height ( n=1), and simple falls ( n=7). One patient had an open fracture treated with an external fixator and experienced delayed fracture healing. The remaining patients were closed fractures, with an average time from injury to operation of 5.8 days (range, 2-10 days). Operation time and postoperative hospital stay were documented. During follow-up, X-ray films were taken to observe the fracture healing, and the bilateral femoral length, femoral neck-shaft angle, widest femoral neck diameter (FND), and articular trochanteric distance (ATD) were measured at last follow-up. Hip function was assessed using the Harris score. The differences in the all indicators between the healthy and affected sides were compared. RESULTS: The operation time ranged from 65 to 130 minutes (mean, 94.1 minutes). Postoperative hospital stay ranged from 5 to 40 days (mean, 16.7 days). All patients were followed up 7-36 months (mean, 14.4 months). One patient exhibited delayed fracture healing during follow-up. The distal locking nail was removed at 6 months after operation, and partial weight-bearing was initiated following dynamic fracture stabilization. The fracture healing was achieved, and the intramedullary nail was removed at 24 months after operation. The other fractures healed with the healing time of 6-20 months (mean, 9.6 months), and the intramedullary nails were removed. During follow-up, no femoral fracture, abnormal development of the greater trochanter, or ischemic necrosis of the femoral head occurred. At last follow-up, there was no significant difference in femoral length, femoral neck-shaft angle, FND, ATD, or Harris score between the affected and healthy sides ( P>0.05). CONCLUSION For older children and adolescents with femoral neck fractures, the application of EALFN fixation aligns more closely with the principles of intramedullary central fixation and rapid rehabilitation. This approach is associated with fewer complications and superior short-term effectiveness.
Humans ; Male ; Femoral Fractures/surgery* ; Female ; Child ; Adolescent ; Retrospective Studies ; Bone Nails ; Fracture Fixation, Intramedullary/instrumentation* ; Fracture Healing ; Treatment Outcome

OBJECTIVE: To investigate the effectiveness of 5G remote robotic surgery in the treatment of pelvic fractures. METHODS: A retrospective analysis was conducted on the clinical data of 160 patients with pelvic fractures admitted between July 2023 and June 2024 who met the selection criteria. Among these patients, 80 underwent internal fixation surgery with the assistance of 5G remote robotic surgery (5G group), while 80 received local robotic surgical assistance (control group). Baseline characteristics, including gender, age, body mass index, disease duration, cause of injury, and fracture classification, were compared between the two groups, and no significant difference was found ( P>0.05). The incision length, operation time, intraoperative blood loss, hospital stay, accuracy of screw placement, maximum residual displacement postoperatively, quality of fracture reduction, incidence of complications, Majeed pelvic function score and classification at last follow-up were recorded and compared between the two groups. RESULTS: In the 5G group, 180 screws were implanted during surgery, while 213 screws were implanted in the control group. The 5G group demonstrated significantly reduced intraoperative blood loss and shorter incision length compared to the control group ( P<0.05). No significant difference was observed between the two groups in terms of operation time or hospital stay ( P>0.05). Radiographic evaluation revealed excellent and good reduction rates of 98.8% (79/80) in the 5G group and 97.5% (78/80) in the control group, while excellent and good screw placement accuracy rates were 98.3% (177/180) in the 5G group and 95.8% (204/213) in the control group. No significant difference was found between the two groups in maximum residual displacement, reduction quality, or screw placement accuracy ( P>0.05). All patients were followed up 7-16 months (mean, 11.3 months), with no significant difference in follow-up duration between the groups ( P>0.05). No perioperative or follow-up complication, such as wound infection, iatrogenic fractures, iatrogenic neurovascular injury, screw loosening or breakage, or nonunion, were observed in either group. The control group exhibited a worse degree of gait alteration compared to the 5G group ( P<0.05), while no significant difference was found in incidences of squatting limitation or persistent pain ( P>0.05). At last follow-up, no significant difference was observed between the groups in Majeed pelvic function scores or grading ( P>0.05). CONCLUSION Compared with the local surgery group, 5G remote robotic surgery supported by remote expert technical guidance demonstrated smaller incision lengths, less intraoperative blood loss, and fewer postoperative complications, and was shown to be a precise, minimally invasive, safe, and reliable surgical method.
Humans ; Robotic Surgical Procedures/instrumentation* ; Pelvic Bones/surgery* ; Male ; Retrospective Studies ; Fracture Fixation, Internal/instrumentation* ; Female ; Fractures, Bone/surgery* ; Middle Aged ; Bone Screws ; Adult ; Operative Time ; Treatment Outcome ; Blood Loss, Surgical ; Length of Stay ; Postoperative Complications/epidemiology* ; Aged ; Young Adult

OBJECTIVE: To compare the effectiveness and shoulder function of reverse total shoulder arthroplasty (RTSA) and open reduction and internal fixation (ORIF) in the treatment of Neer three/four-part proximal humeral fractures in the elderly. METHODS: Randomized controlled analysis was conducted on 68 patients over 70 years old with Neer three/four-part proximal humeral fractures treated with RTSA or ORIF between January 2020 and June 2022. The patients were randomly divided into RTSA group ( n=32) and ORIF group ( n=36). There was no significant difference ( P>0.05) in the baseline data such as age, gender, body mass index, injured side, Neer classification, and preoperative Charlson comorbidity index, visual analogue scale (VAS) score, Constant shoulder score, Oxford shoulder score (OSS), and hemoglobin (Hb). The operation time, intraoperative blood loss, reduction of Hb on the 3rd day after operation, hospital stay, total cost of hospitalization, complication incidence, range of motion of shoulder joint at 2 years after operation, VAS score before operation and at 5 days and 1 month after operation, Constant shoulder score and OSS score before operation and at 2 years after operation, and imaging results during follow-up were recorded and compared between the two groups. RESULTS: Compared with the ORIF group, the RTSA group had longer operation time, less intraoperative blood loss, and higher total cost of hospitalization ( P<0.05). There was no significant difference in Hb reduction on the 3rd day after operation between the two groups ( P>0.05). The VAS scores significantly improved in both groups at 5 days and 1 month after operation ( P<0.05), but there was no significant difference between the two groups ( P>0.05). All patients were followed up 26-35 months, with an average of 31.2 months. In the RTSA group, there were 2 cases of poor healing of superficial incision and 1 case of transient nerve injury. There was no complication such as bone resorption around the prosthesis, lucent band, prosthesis loosening, or periprosthetic fracture in all patients. In the ORIF group, there was 1 case of poor healing of superficial incision, 3 cases of nonunion of fracture, 1 case of arthritis secondary to humeral head necrosis, and 1 case of bone absorption of large tuberosity, and no displacement or fracture failure of internal fixation was found in all patients. There was no significant difference in the incidence of complications [9.4% (3/32) vs 16.7% (6/36)] between the two groups [ OR (95% CI): 0.828 (0.171, 4.014), P=0.814]. In the RTSA group, 28 cases were graded 0 and 4 cases were graded 1 at 2 years after operation. Constant and OSS scores of RTSA group were significantly better than those of ORIF group ( P<0.05). The Constant score was significantly better than ORIF group in activity and strength, range of motion, lifting, abduction, and external rotation ( P<0.05), and there was no significant difference in pain, daily function, and internal rotation between the two groups ( P>0.05). The RTSA group had a significantly greater range of motion in lifting, abduction, and external rotation than ORIF group ( P<0.05), but there was no significant difference in internal rotation between the two groups ( P>0.05). CONCLUSION Application of RTSA as the initial treatment of Neer three/four-part proximal humeral fractures in the elderly can achieve better rehabilitation of joint activity and lower risk of early reoperation, and improve the quality of life of elderly fracture patients. However, the difficulty of revision and the high cost of treatment require the surgeon to pay full attention and strictly grasp the indications.
Humans ; Fracture Fixation, Internal/instrumentation* ; Male ; Female ; Shoulder Fractures/surgery* ; Arthroplasty, Replacement, Shoulder/methods* ; Aged ; Bone Plates ; Open Fracture Reduction/methods* ; Range of Motion, Articular ; Treatment Outcome ; Shoulder Joint/physiopathology* ; Aged, 80 and over ; Operative Time ; Postoperative Complications/epidemiology* ; Length of Stay

OBJECTIVE: To investigate the effectiveness of knee arthroscopy with wire anchor nailing composite double pulley technique in the treatment of anterior cruciate ligament (ACL) tibial avulsion fracture involving the anterior root of the lateral meniscus (LM). METHODS: Clinical data of 35 patients with ACL tibial avulsion fracture involving the anterior root of the LM admitted between January 2019 and September 2023 and met the selection criteria were retrospectively analysed. There were 20 males and 15 females; ages ranged from 10 to 57 years, with a mean of 29 years. The time from injury to surgery ranged from 3 to 20 days, with a mean of 9.6 days. Meyers-McKeever classification included 5 cases of type Ⅱ, 12 cases of type Ⅲ, and 18 cases of type Ⅳ. Preoperative anterior knee instability Lachman test and anterior drawer test were positive. The anterior root of the LM as well as the avulsion fracture block were fixed using suture anchor nails compounded with double pulley technique under arthroscopy. Postoperative X-ray films were performed to assess fracture healing; knee stability was assessed using the anterior drawer test and Lachman test, anterior laxity of the knee was measured by KT-2000, and knee function was assessed using the Lysholm score and the International Knee Documentation Committee (IKDC) score; at last follow-up, the recovery of the meniscus was assessed using the McMurry test and knee hyperextension test. RESULTS: All the patients were successfully operated, the operation time ranged from 56 to 78 minutes,with an average of 67.6 minutes, and there was no nerve or blood vessel injury during operation. Thirty-five cases were followed up 12-18 months with an average of 15.1 months. During the follow-up, there was no infection, knee stiffness, loosening of internal fixation, fracture displacement, or re-fracture. The fractures all healed, with a clinical healing time of 8-15 weeks, averaging 10.9 weeks. At last follow-up, 4 patients had weakly positive anterior drawer test and Lachman test, and the rest were negative; McMurry test and knee hyperextension test were negative; no patient complained of knee extension pain or straightening obstacles, and all the patients resumed their normal life or sports and labour; 16 patients with unclosed epiphyses did not have any epiphyseal injuries or growth disorders. Lysholm score, IKDC score, and KT-2000 anterior knee laxity at last follow-up significantly improved when compared with preoperative ones ( P<0.05). CONCLUSION The treatment of ACL tibial avulsion fracture involving the anterior root of the LM with suture anchor composite double pulley technique can effectively fix the anterior root of the LM while fixing the avulsion fracture block, and better restore the function and stability of the knee joint.
Humans ; Male ; Female ; Adult ; Arthroscopy/methods* ; Adolescent ; Retrospective Studies ; Tibial Fractures/surgery* ; Young Adult ; Middle Aged ; Fractures, Avulsion/surgery* ; Fracture Fixation, Internal/instrumentation* ; Anterior Cruciate Ligament Injuries/surgery* ; Child ; Treatment Outcome ; Suture Anchors ; Menisci, Tibial/surgery* ; Tibial Meniscus Injuries/surgery* ; Bone Nails ; Knee Joint/surgery*

OBJECTIVE: To compare the effectiveness of different puncture methods of the flexible bone cement delivery device in unilateral percutaneous curved vertebroplasty for osteoporotic vertebral upper 1/3 compression fractures. METHODS: A retrospective analysis was conducted on the clinical data of 67 patients with osteoporotic vertebral upper 1/3 compression fractures who were admitted and met the selection criteria between January 2023 and April 2024. The patients were divided into two groups based on the puncture method of the flexible bone cement delivery device: the oblique puncture group ( n=37) and the parallel puncture group ( n=30). There was no significant difference ( P>0.05) between the two groups in terms of gender, age, bone mineral density (T value), distribution of fractured vertebrae, time from injury to operation, and preoperative visual analogue scale (VAS) score for pain, Oswestry disability index (ODI), anterior vertebral height of the fractured vertebra, and Cobb angle of the fractured vertebra. The following parameters were compared between the two groups: operation time, incidence of secondary puncture, incidence of bone cement leakage, volume of injected bone cement, bone cement distribution score, as well as VAS score, ODI, anterior vertebral height of the fractured vertebra, and Cobb angle of the fractured vertebra at 1 day after operation and at last follow-up. RESULTS: Two cases in the oblique puncture group and 7 cases in the parallel puncture group underwent secondary puncture during operation, and the difference in the incidence of secondary puncture was significant ( P<0.05). No complications such as bone cement hypersensitivity, bone cement embolism, nerve injury, or epidural hematoma occurred in both groups. There was no significant difference in operation time, volume of injected bone cement, incidence of bone cement leakage, distribution score and rating of bone cement between the two groups ( P>0.05). All patients were followed up 6-18 months (mean, 12.0 months), and there was no significant difference in the follow-up time between the two groups ( P>0.05). No further fracture collapse or compression occurred in the fractured vertebra during follow-up. Both groups exhibited significant improvements in VAS score, ODI, anterior vertebral height, and Cobb angle of the fractured vertebra after operation compared to baseline ( P<0.05). There were also significant differences between the two time points after operation ( P<0.05). However, there was no significant difference in the above indicators between the two groups ( P>0.05). CONCLUSION For osteoporotic vertebral upper 1/3 compression fractures treated with unilateral percutaneous curved vertebroplasty, both oblique and parallel puncture methods of the flexible bone cement delivery device can effectively relieve pain, but the former is more conducive to reducing the incidence of secondary puncture.
Humans ; Bone Cements/therapeutic use* ; Fractures, Compression/surgery* ; Retrospective Studies ; Vertebroplasty/instrumentation* ; Osteoporotic Fractures/surgery* ; Spinal Fractures/surgery* ; Female ; Male ; Aged ; Middle Aged ; Treatment Outcome ; Punctures/methods* ; Aged, 80 and over

OBJECTIVE: To explore the effectiveness of proximal femoral nail antirotation (PFNA) combined with minimally invasive clamp reduction technique by Kocher pincers in the treatment of irreducible intertrochanteric femoral fracture in the elderly. METHODS: The clinical data of 35 elderly patients with irreducible intertrochanteric femoral fractures who were treated with PFNA combined with minimally invasive clamp reduction technique by Kocher pincers between January 2016 and December 2022 were retrospectively analysed. There were 16 males and 19 females, aged from 63 to 95 years (mean, 75.2 years). The causes of injury included traffic accident in 3 cases and falling in 32 cases. The time from injury to operation was 2-11 days (mean, 3.6 days). According to AO/Orthopaedic Trauma Association (AO/OTA) classification system for intertrochanteric fractures, there were 14 cases of type A1, 18 cases of type A2, and 3 cases of type A3. According to the displacement of fracture by intraoperative fluoroscopy, there were 5 cases with only coronal displacement, 17 cases with only sagittal displacement, and 13 cases with both coronal and sagittal displacement. The operation time, intraoperative blood loss, rate of hemoglobin decline at 1 day after operation, length of hospital stay, and fracture healing time were recorded. The reduction quality of fracture during operation was evaluated according to reduction quality criteria proposed by Chang et al. The Harris scoring system was used to evaluate the hip joint function at last follow-up. RESULTS: The operation time was 45-105 minutes (mean, 54.4 minutes); the intraoperative blood loss was 80-300 mL (mean, 116.3 mL). The reduction quality of fracture during operation was good in 22 cases (62.9%) and acceptable in 13 cases (37.1%). The rate of hemoglobin decline at 1 day after operation ranged from 6.2% to 18.6% (mean, 10.2%); the length of hospital stay was 5-18 days (mean, 7.2 days). One case died of respiratory failure due to pulmonary infection, 2 cases were lost to follow-up, and the remaining 32 cases were followed up 6-24 months (mean, 10.6 months). All 32 patients achieved bony union and the healing time was 3-9 months (mean, 3.6 months). There was no complication such as incision infection, internal fixation failure, or coxa varus during follow-up. At last follow-up, the Harris score of hip joint was 67-96 (mean, 88.9); among them, 19 cases were excellent, 10 cases were good, 2 cases were fair, and 1 case was poor, with an excellent and good rate of 90.6%. CONCLUSION For the elderly patients with irreducible intertrochanteric femoral fracture, the application of PFNA combined with minimally invasive clamp reduction technique by Kocher pincers can achieve high-quality fracture reduction, which has the advantages of simple reduction operation, less trauma, and can avoid the radiation exposure of operators during maintenance reduction.
Humans ; Male ; Female ; Aged ; Minimally Invasive Surgical Procedures/methods* ; Hip Fractures/diagnostic imaging* ; Bone Nails ; Aged, 80 and over ; Retrospective Studies ; Fracture Fixation, Intramedullary/instrumentation* ; Middle Aged ; Treatment Outcome ; Fracture Fixation, Internal/instrumentation* ; Fracture Healing ; Femoral Fractures/surgery*

OBJECTIVE: To compare the effectiveness of posterior axillary edge approach and arthroscopic assisted reduction in the treatment of Ideberg type Ⅰ and Ⅱ glenoid fracture of the scapula. METHODS: The clinical data of 26 patients with fresh Ideberg type Ⅰ and Ⅱ scapular fractures admitted between June 2021 and September 2024 who met the selection criteria were analyzed retrospectively. The patients were divided into two groups according to different treatment methods. Ten cases in the posterior axillary edge group were fixed by open reduction plate through the posterior axillary edge approach, and 16 cases in the arthroscopy group were treated with suture anchor fixation under arthroscopy. There was no significant difference in baseline data between the two groups ( P>0.05), such as gender, age, surgical side, Ideberg type, cause of injury, time from injury to operation, rotator cuff injury, and superior labrum anterior posterior (SLAP) injury, etc. The operation time and fracture healing time were recorded and compared between the two groups, and the shoulder pain was evaluated by visual analogue scale (VAS) score at 1 week, 1 month, and 3 months after operation. At 3 and 6 months after operation, the range of motion of shoulder joint in anteflexion, abduction, external rotation, internal rotation, and backward extension was evaluated, the upper limb dysfunction was evaluated by the Disability Assessment Scale of Arm, Shoulder, and Hand (DASH), and the shoulder joint function was evaluated by the Constant-Murley score. The differences between 6 months and 3 months after operation (changes) were statistically analyzed. RESULTS: Patients in both groups were followed up 11-13 months, with an average of 12.5 months. The operation time and fracture healing time in the posterior axillary edge group were significantly shorter than those in the arthroscopy group ( P<0.05). There was no complication such as wound infection, vascular and nerve injury, loss of reduction, bone nonunion, or glenohumeral instability in both groups. At 1 week after operation, the VAS score in the posterior axillary edge group was significantly higher than that in the arthroscopy group ( P<0.05); there was no significant difference in the VAS score between the two groups at 1 and 3 months after operation ( P>0.05). At 6 months after operation, the changes of shoulder joint in anteflexion, internal rotation range of motion and DASH scores in the posterior axillary edge group were significantly lower than those in the arthroscopy group ( P<0.05), while the changes of abduction, external rotation, backward extension range of motion and Constant-Murley scores were not significantly different between the two groups ( P>0.05). CONCLUSION For Ideberg type Ⅰ and Ⅱ glenoid fracture of the scapula, the posterior axillary edge approach for internal fixation has a short operation time, fast fracture healing, and is beneficial for early functional recovery; arthroscopic assisted reduction has minimal trauma and can handle joint injuries simultaneously. Both surgical procedures are safe and effective, and individualized selection should be made based on soft tissue conditions and combined injuries.
Humans ; Arthroscopy/methods* ; Scapula/surgery* ; Male ; Female ; Retrospective Studies ; Adult ; Fracture Fixation, Internal/instrumentation* ; Fractures, Bone/surgery* ; Middle Aged ; Treatment Outcome ; Bone Plates ; Suture Anchors ; Fracture Healing ; Range of Motion, Articular ; Young Adult ; Shoulder Joint/surgery* ; Operative Time

OBJECTIVE: To compare the effectiveness of early versus delayed closed reduction and percutaneous Kirschner wire fixation in the treatment of pediatric supracondylar humerus fractures. METHODS: A retrospective analysis was conducted on 468 children with supracondylar humerus fractures, who were admitted between January 2020 and December 2023 and met the inclusion criteria. Among them, 187 children were treated during 12 hours after injury (early operation group) and 281 were treated after 12 hours (delayed operation group). There was no significant difference between the two groups ( P>0.05) in the gender, age, injury mechanism, fracture side and type, while there was significant difference in interval from injury to operation ( P<0.05). The operative outcomes, including the operation time, intraoperative blood loss, the length of hospital stay, fracture healing time, elbow function assessed by Flynn criteria at 3 months after operation, and complications, were compared. RESULTS: Compared to the delayed operation group, the early operation group demonstrated significantly shorter operation time and less intraoperative blood loss ( P<0.05). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). All children were followed up 3-12 months. The follow-up time was (6.7±2.9) months in the early operation group and (6.9±2.8) months in the delayed operation group, showing no significant difference between the two groups ( P>0.05). There was no significant difference in the fracture healing time between the two groups ( P>0.05). At 3 months after operation, the early operation group exhibited superior Flynn elbow functional outcomes to the delayed operation group ( P<0.05). In the early operation group, there was 1 case of fracture non-union and 3 cases of cubital varus deformity after operation. In the delayed operation group, there was 1 case of nerve injury, 7 cases of fracture non-union, and 12 cases of cubital varus deformity after operation. There was significant difference in the incidence of complications between the two groups ( P<0.05). One case of the early operation group and 10 cases of the delayed operation group underwent secondary operation, showing no significant difference in the incidence of secondary operation between the two groups ( P>0.05). CONCLUSION For pediatric supracondylar humerus fractures, early closed reduction and percutaneous Kirschner wire fixation can reduce operation time, minimize intraoperative blood loss and postoperative complications, and improve the functional recovery compared to delayed operation.
Humans ; Humeral Fractures/surgery* ; Bone Wires ; Retrospective Studies ; Male ; Female ; Child ; Fracture Fixation, Internal/instrumentation* ; Child, Preschool ; Treatment Outcome ; Operative Time ; Fracture Healing ; Length of Stay ; Closed Fracture Reduction/methods* ; Blood Loss, Surgical ; Time Factors ; Time-to-Treatment ; Postoperative Complications/epidemiology*

OBJECTIVE: To compare the biomechanical properties of personalized Y-shaped plates with horizontal plates, vertical plates, and traditional Y-shaped plates in the treatment of distal humeral intra-articular fractures through finite element analysis, and to evaluate their potential for clinical application. METHODS: The study selected a 38-year-old male volunteer and obtained a three-dimensional model of the humerus by scanning his upper limbs using a 64-slice spiral CT. Four types of fracture-internal fixation models were constructed using Mimics 19.0, Geomagic Wrap 2017, Creo 6.0, and other software: horizontal plates, vertical plates, traditional Y-shaped plate, and personalized Y-shaped plate. The models were then meshed using Hypermesh 14.0 software, and material properties and boundary conditions were defined in Abaqus 6.14 software. AnyBody 7.3 software was used to simulate elbow flexion and extension movements, calculate muscle strength, joint forces, and load torques, and compare the peak stress and maximum displacement of the four fixation methods at different motion angles (10°, 30°, 50°, 70°, 90°, 110°, 130°, 150°) during elbow flexion and extension. RESULTS: Under dynamic loading during elbow flexion and extension, the personalized Y-shaped plate exhibits significant biomechanical advantages. During elbow flexion, the peak internal fixation stress of the personalized Y-shaped plate was (28.8±0.9) MPa, which was significantly lower than that of the horizontal plates, vertical plates, and traditional Y-shaped plate ( P<0.05). During elbow extension, the peak internal fixation stress of the personalized Y-shaped plate was (18.1±1.6) MPa, which was lower than those of the other three models, with significant differences when compared with horizontal plates and vertical plates ( P<0.05). Regarding the peak humeral stress, the personalized Y-shaped plate model showed mean values of (10.9±0.8) and (13.1±1.4) MPa during elbow flexion and extension, respectively, which were significantly lower than those of the other three models ( P<0.05). Displacement analysis showed that the maximum displacement of the humerus with the personalized Y-shaped plate during elbow flexion was (2.03±0.08) mm, slightly higher than that of the horizontal plates, but significantly lower than that of the vertical plates, showing significant differences ( P<0.05). During elbow extension, the maximum displacement of the humerus with the personalized Y-shaped plate was (1.93±0.13) mm, which was lower than that of the other three models, with significant differences when compared with vertical plates and traditional Y-shaped plates ( P<0.05). Stress contour analysis showed that the stress of the personalized Y-shaped plate was primarily concentrated at the bifurcation of the Y-shaped structure. Displacement contour analysis showed that the personalized Y-shaped plate effectively controlled the displacement of the distal humerus during both flexion and extension, demonstrating excellent stability. CONCLUSION The personalized Y-shaped plate demonstrates excellent biomechanical performance in the treatment of distal humeral intra-articular fractures, with lower stress and displacement, providing more stable fixation effects.
Humans ; Male ; Adult ; Healthy Volunteers ; Finite Element Analysis ; Tomography, Spiral Computed ; Models, Anatomic ; Biomechanical Phenomena ; Humeral Fractures, Distal/surgery* ; Fracture Fixation, Internal/instrumentation* ; Bone Plates ; Computer Simulation ; Precision Medicine/methods* ; Elbow Joint/surgery* ; Elbow/surgery* ; Humerus/surgery* ; Torque ; Stress, Mechanical ; Intra-Articular Fractures/surgery* ; Prosthesis Design/methods* ; Imaging, Three-Dimensional ; Range of Motion, Articular

OBJECTIVE: To investigate whether adding 1 transverse screw (TS) to the triangular parallel cannulated screw (TPCS) fixation has a mechanical stability advantage for Pauwels type Ⅲ femoral neck fractures by conducting finite element analysis on four internal fixation methods. METHODS: Based on CT data of a healthy adult male volunteer's femur, three Pauwels type Ⅲ femoral neck fracture models (Pauwels angle 70°, Pauwels angle 80°, and Pauwels angle 70° combined with bone defect) were constructed using Mimics 21.0 software and SolidWorks 2017 software. Four different internal fixation models were built at the same time, including TPCS, TPCS+TS, three cross screws (TCS), and TPCS+medial buttress plate (MBP). The mechanical stability of different models under the same load was compared by finite element analysis. RESULTS: The femoral model established in this study exhibited a maximum stress of 28.62 MPa, with relatively higher stress concentrated in the femoral neck. These findings were comparable to previous studies, indicating that the constructed femoral finite element model was correct. The maximum stress of internal fixation in finite element analysis showed that TCS was the lowest and TPCS+MBP was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. The maximum displacement of internal fixation in each fracture model was located at the top of the femoral head, with TCS having the highest maximum displacement of the femur. The maximum stress of fracture surface in finite element analysis showed that TCS was the lowest and TPCS was the highest in the Pauwels angle 70° model, while TPCS+MBP was the lowest and TPCS/TCS were the highest in the Pauwels angle 80° model and the Pauwels angle 70° combined with bone defect model, respectively. The maximum displacement of fracture surfece analysis showed that TPCS+MBP was the lowest and TCS was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. CONCLUSION For Pauwels type Ⅲ femoral neck fractures, the biomechanical stability of TPCS+TS was superior to that of TPCS alone and TCS, but it has not yet reached the level of TPCS+MBP.
Finite Element Analysis ; Humans ; Femoral Neck Fractures/diagnostic imaging* ; Bone Screws ; Fracture Fixation, Internal/instrumentation* ; Male ; Bone Plates ; Stress, Mechanical ; Biomechanical Phenomena ; Tomography, X-Ray Computed ; Adult ; Femur Neck/surgery*