RESUMEN

Hangman's fracture occurs in the elderly following low kinetic energy fall from their height, or in the young during traffic accident. Classically described as bipedicular C2 fracture, Hangman's fracture results from oblique hyperextension-flexion vector forces which can lead to anterior dislocation of C1C2 complex over C3 vertebral body in case of associated damage to C2C3 disc and ligaments. Even though most cases of Hangman's fracture are not displaced (grade 1) and can be managed with orthopaedic treatment using cervical brace, highly displaced cases of Hangman's fractures (some grade 2, all grade 3) require surgical stabilization. Given the limited capabilities of reduction and the odds for mechanical failure of anterior C2C3 discectomy and fusion, we provide a reproducible method using a specific rod persuader on C1 screws aiming to realign and stabilize displaced cases of Hangman fracture using the C1C3 "Harms-Goel" procedure.

Asunto(s)

RESUMEN

During the last decades, effective pain reduction and early mobilization were identified as the central priorities in therapy of insufficiency fractures of the pelvis. For operative treatment minimally-invasive stabilization techniques are favored. While there is consensus on the significance of sufficient dorsal stabilization the role of additional fixation of the anterior fracture component stays under discussion. Within the present study we developed an internal ring fixator system (RingFix) with the question whether an in-itself-closed construct can improve stability of the entire ring structure. RingFix was evaluated on an osteoporotic bone model with a standardized FFP IIIc fracture within an established biomechanical setup regarding its primary stabilization potential. Further, it was compared to transiliac-transsacral screw fixation with and without stabilization of the anterior fracture component. The transiliac-transsacral fixation with separate screw fixation of the anterior fracture showed significantly higher stability than the RingFix and the transiliac-transsacral screw fixation without anterior stabilization. Our results show that stabilization of the anterior fracture component relevantly improves the stability of the entire ring construct. As a bridging stabilizer, RingFix shows biomechanical advantages over an isolated dorsal fracture fixation, but inferior results than direct stabilization of the single fracture components.

Asunto(s)

RESUMEN

This study focuses on evaluating the failure resistance of a previously reduced tibia with internal fixation implants as PLate (PL) or InterMedullary Nail (IMN), subjected later to a tibial lateral trauma. To replicate this type of trauma, which can be caused by a road accident, a three-point bending test is considered using experimental tests and numerical simulations. The withstand evaluation of the tibia-PL and tibia-IMN structures was conducted by following the load transfer through, the bone and the used implants. The analysis, up to tibia failure, required the use of an elasto-plastic behavior law coupled to damage. The model parameters were identified using experimental tests. Il was shown that the tibia-IMN structure provided a bending resistant load up to three-times higher than the tibia-PL. In fact, the used screws for plate fixation induced a high level of stress in the vicinity of threaded region, leading to a crack initiation and a damage propagation. However, in tibia-IMN structure the highest stress was generated in the trapped zone between the loader and the nail, promoting crack formation. From a biomechanical point of view, the structure with IMN is safer than the structure with PL, whose fixation induces earlier damage in bone.

Asunto(s)

RESUMEN

To explore the biomechanical effects of different internal fixation methods on femoral neck fractures under various postoperative conditions, mechanical analyses were conducted, including static and dynamic assessments. Ultimately, a mechanical stability evaluation system was established to determine the weights of each mechanical index and the evaluation scores for each sample. In static analysis, it was found that the mechanical stability of each model met the fixation requirements post-fracture. During the healing process, the maximum stress on the hollow nail slightly increased, and stress distribution shifted from multi-point to a more uniform single-point distribution, which contributes to fracture healing and reduces the risk of stress concentration. In dynamic analysis, resonance points frequently occurred at low frequencies. With increasing walking speed, the maximum stress increased significantly. At slow speeds, the maximum stress approached the material's yield limit. Under cyclic dynamic loading, the number of cycles barely met the requirements of the healing period, and increasing walking speed may lead to fatigue fractures. The evaluation model established in this study comprehensively considers different mechanical performances in static and dynamic analyses. Based on various mechanical analyses and evaluation systems, the applicability of internal fixation treatment plans can be assessed from multiple dimensions, providing the optimal simulated mechanical solution for each case of femoral neck fracture treatment.

Asunto(s)

RESUMEN

BACKGROUND: Recent literature has found a consensus in favor of conservative treatment for type II supracondylar humeral fractures (SCHF). This retrospective observational study compares the short- to medium-term functional outcomes of conservative versus surgical treatment in 31 patients with SCHF (Gartland II and III) to assess the potential superiority of one approach over the other. MATERIALS AND METHODS: Thirty-one pediatric patients treated for SCHF-19 classified as Gartland II and 12 as Gartland III-were assessed in our department. Eight patients underwent closed reduction and cast immobilization, 22 were treated with closed reduction and percutaneous pinning, and one underwent open reduction and internal fixation with plates. Clinical and functional data were collected during follow-up, including elbow and forearm range of motion (ROM), grip strength, carrying angle, Flynn's criteria, and Disabilities of the Arm, Shoulder, and Hand (DASH) score. RESULTS: The average follow-up was 3.3 years (± 1.4 years). All patients demonstrated good functional recovery. According to Flynn's criteria, 85% and 81% of the patients achieved a satisfactory outcome in elbow flexion and carrying angle, respectively. No cases of nerve injuries were reported. Four patients developed cubitus varus in the Gartland II group, which was treated with closed reduction and casting with the initial alignment maintained (without a loss of reduction during the first week). However, compared to this group that was conservatively treated, functional and clinical outcomes were significantly better in the group with SCHF Gartland II treated with reduction and pinning (p < 0.05). CONCLUSIONS: Although some recent studies have demonstrated positive outcomes with conservative treatment for both Gartland IIA and IIB fractures, the short- to medium-term functional results in our study emphasize that superior outcomes were obtained with surgical treatment for Gartland II fractures when compared to those treated conservatively. TRIAL REGISTRATION: This study was performed in line with the principles of the Declaration of Helsinki. Ethics approval was obtained from our institute's ethics committee (registry no. 3511). LEVEL OF EVIDENCE: Therapeutic level III.

Asunto(s)

RESUMEN

PURPOSE: This study aimed to compare the clinical outcomes and differences in biomechanical characteristics between the femoral neck system (FNS) and cannulated cancellous screws (CCSs) in the treatment of femoral neck fractures. METHODS: This study retrospectively analysed a cohort of 38 registered cases of femoral neck fractures treated surgically with either the FNS (n = 17) or CCSs (n = 21) between January 2020 and December 2023. Indicators such as fluoroscopy frequency, length of hospital stay, and fracture healing time were compared between the two groups. Functional status was evaluated via the Harris hip score (HHS) and visual analogue scale (VAS), whereas prognosis was assessed based on changes in the neck shaft angle and femoral neck shortening. Additionally, six sets of femoral neck fracture models were developed based on Pauwels angles of 30°, 40°, 50°, 60°, 70°, and 80°. Two experimental groups, FNS and CCS, were established, and a joint reaction force of 1800 N was applied to the proximal femur. The displacement, stress, and stiffness of the components of interest in the different models were tested and compared. RESULTS: The distributions of all the baseline characteristics were similar between the two groups (p > 0.05). The FNS group presented significantly shorter fluoroscopy frequency, length of hospital stay, and fracture healing time (p < 0.05). Harris and VAS scores were higher in the FNS group than in the CCS group (p < 0.05). Postoperative changes in the neck shaft angle and femoral neck shortening were significantly lower in the FNS group than in the CCS group (p < 0.05). The results of the finite element analysis indicated that the maximum stress on the femoral head and varus angle were generally lower in the FNS group than in the CCS group and that the maximum displacement of the femoral head and FNS was generally lower in the FNS group than in the CCS group. However, the superiority of FNS over CCS decreased with increasing Pauwels angle. Additionally, the effectiveness of FNS in limiting displacement of the femoral neck upper wall was not as favourable as that of CCS. CONCLUSIONS: The treatment of femoral neck fractures with FNS is superior and contributes to improved hip joint function. Biomechanical research has confirmed its structural stability and advantages in resisting femoral head varus. However, challenges to its fixation efficacy persist, particularly at higher Pauwels angles.

Asunto(s)

RESUMEN

BACKGROUND: Acromioclavicular joint (ACJ) disruptions are corrected by surgery either with an endobutton or a hook plate. The results in the long term were found to be similar in many randomized controlled trials. This study aims to conduct a meta-analysis to evaluate the functional outcome and complications of double endo button versus clavicular hook plate (CHP) for ACJ disruption (Rockwood types III-VI). MATERIALS AND METHODS: Two authors independently searched related articles from electronic databases (PubMed, Google Scholar, MEDLINE, SCOPUS, and Web of Science) till January 26, 2022. The data were extracted from the related articles and analyzed by Stata software. For bias calculation of each study, the Newcastle-Ottawa scale and the RevMan 5.4 software were used. RESULTS: 14 cohort studies, 2 randomized control trial studies, and 1 case-control study including patients were selected in this meta-analysis. The results of our study showed a significantly higher Constant-Murley Score (WMD 5.79, 95% confidence interval [CI] 2.23-9.36), Visual Analog Scale (WMD- 0.63, 95% CI [-0.79, -0.46]) and University of California at Los Angeles shoulder score (UCLA) scale (WMD 3.32, 95% CI [2.87, 3.77]) for double endobutton group. At the same time, some complications like implant failure were more common in the double endobutton group. CONCLUSION: This meta-analysis shows better functional and clinical outcomes of shoulder joint for the treatment of acromioclavicular joint (ACJ) disruption cases (Rockwood types III-VI) with no need for secondary operation, unlike the CHP. Complications like subacromial erosion, ACJ arthrodesis, and infection rate are higher in the CHP group, whereas the chance of implant failure is higher in the double endobutton group.

RésuméLes perturbations de l'articulation acromio-claviculaire (ACJ) sont corrigées par chirurgie soit avec un endobouton, soit avec une plaque à crochets. Les résultats à long terme se sont révélés similaires dans de nombreux essais contrôlés randomisés. Cette étude vise à mener une méta-analyse pour évaluer les résultats fonctionnels et les complications du double endobouton par rapport à la plaque à crochet claviculaire (CHP) pour la perturbation de l'ACJ (Rockwood types III ­ VI).Matériels et méthodes:Deux auteurs ont recherché indépendamment des articles connexes dans des bases de données électroniques (PubMed, Google Scholar, MEDLINE, SCOPUS et Web of Science) jusqu'au 26 janvier 2022. Les données ont été extraites des articles connexes et analysées par le logiciel Stata. Pour le calcul du biais de chaque étude, l'échelle de Newcastle-Ottawa et le logiciel RevMan 5.4 ont été utilisés.Résultats:14 études de cohorte, 2 études d'essais contrôlés randomisés et 1 étude cas-témoins incluant des patients ont été sélectionnées dans cette méta-analyse. Les résultats de notre étude ont montré un score de Constant-Murley significativement plus élevé (WMD 5,79, intervalle de confiance [IC] à 95 % 2,23­9,36), une échelle visuelle analogique (WMD− 0,63, IC à 95 % [−0,79, −0,46]) et un score universitaire. de Californie sur l'échelle de score d'épaule de Los Angeles (UCLA) (WMD 3,32, IC à 95 % [2,87, 3,77]) pour le groupe à double endobouton. Dans le même temps, certaines complications comme l'échec de l'implant étaient plus fréquentes dans le groupe à double endobouton.Conclusion:Cette méta-analyse montre de meilleurs résultats fonctionnels et cliniques de l'articulation de l'épaule pour le traitement des cas de rupture de l'articulation acromio-claviculaire (ACJ) (types Rockwood III à VI) sans nécessité d'opération secondaire, contrairement à la CHP. Les complications telles que l'érosion sous-acromiale, l'arthrodèse de l'ACJ et le taux d'infection sont plus élevées dans le groupe CHP, alors que le risque d'échec de l'implant est plus élevé dans le groupe à double endobouton.

Asunto(s)

RESUMEN

BACKGROUND: Displaced femoral neck fractures are associated with a high revision rate. The new femoral neck system(FNS) offers advantages in fixation stability, potentially reducing the need for revision. The purpose of this study was to compare the revision rate of patients with different reduction quality treated with the FNS and cannulated screws (CS). METHODS: This retrospective study included patients with Garden III or IV femoral neck fractures who underwent osteosynthesis in a level 1 trauma center between July 2019 and June 2023. A total of 141 cases met the inclusion criteria and received treatment with either the FNS (N = 65) or CS (N = 76). The quality of fracture reduction, surgical complications (such as femoral neck shortening, avascular necrosis of femoral head, nonunion of fracture, implant failure and withdrawal), revision surgery and the reasons for revision were analyzed. RESULTS: The mean age of the 141 cases was 52.0 years (range 18-65); with sixty-five cases being male (46.1%). Eighty-four fractures (59.6%) were classified as Garden type III. Reduction quality was good in 71 cases (50.4%) and fair in 70 cases. The mean follow-up period was 25.9 months (range 12-46). A total of 26 cases(18.4%) underwent revision surgery. The revision rate in cases with good reduction was 11.3% (8/71 cases), with seven cases (four hardware removal and three arthroplasty) in the CS group and one case (arthroplasty for fracture nonunion and implant failure) in the FNS group, a significant difference was found between the two groups(P = 0.041). Among the 18 cases (25.7%, 18/70) with fair reduction who underwent revision surgery, nine cases (six hardware removal and three arthroplasty) in the CS group, and nine cases (arthroplasty for implant failure and cut-out) in the FNS group, and there was no significant difference between the two groups (P = 0.672). The total revision rate between the FNS group (15.4%, 10/65) and the CS group (21.1%, 16/76) was not significantly different (P = 0.387). CONCLUSIONS: The total revision rate between the FNS and CS group showed no difference. However, in cases with good reduction, the revision rate was lower in the FNS group compared to the CS group.

Asunto(s)

RESUMEN

Objectives: This study aimed to report the complication rate associated with open reduction and internal fixation (ORIF) of mandibular condyle fractures in Oman. Methods: This retrospective cohort study was conducted among patients who underwent ORIF of mandibular condyle fractures at Al-Nahdha Hospital and the Sultan Qaboos University Hospital in Muscat, Oman, from January 2008 to December 2020. Data collected included patient demographics, fracture aetiology, fracture side and type, surgical approach and recorded complications and outcomes. Results: A total of 68 patients (59 males and 9 females; mean age of 30.1 years) with 83 mandibular condyle fractures underwent ORIF during the study period. Subcondylar fractures were the most common type, occurring in 62.7% of patients, while bilateral fractures were observed in 21 (30.8%) patients. The most common surgical approach was retromandibular, used in 42.2% of patients. The overall complication rate was 42.6%, with the most frequently reported complications being transient facial nerve palsy (18.1%), malocclusion (14.7%) and restricted mouth opening (10.3%). Subsequent surgical interventions to correct malocclusion were performed in 6 cases. There was no statistically significant association between the overall complication rate and the patients' clinical characteristics. Conclusion: Although ORIF of mandibular condyle fractures generally offers favourable outcomes, it carries a risk of complications.

Asunto(s)

RESUMEN

BACKGROUND: Distal femoral fractures account for less than 1% of all fractures. The therapy of choice is usually surgical stabilization. Despite advances in implant development over the past few years, complication rate remains comparatively high. The aim of this study is to analyze our results with plate fixation of distal femoral fractures with a focus on complication and fracture healing rates. METHODS: In this retrospective cohort study, patients (> 18 years) with distal femoral fractures treated at an urban level I trauma center between 2015 and 2022 were analyzed. RESULTS: In total, 206 patients (167 female, 39 male) with an average age of 75 (SD 16) years were diagnosed with a fracture of the distal femur. One hundred fourteen of these patients were treated surgically by means of plate osteosynthesis. In 13 cases (11.41%), a revision procedure had to be performed. The indication for surgical revision was mechanical failure in eight cases (7.02%) and septic complication in five cases (4.39%). Periprosthetic fractures were more likely to cause complications overall (19.6% versus 4.76%) and further included all documented septic complications. The analysis of modifiable surgical factors in the context of plate osteosynthesis showed higher complication rates for cerclage in the fracture area compared with plate-only stabilizations (44.44% versus 22.22%). CONCLUSIONS: The data show an increased amount of revisions and a significantly higher number of septic complications in the treatment of periprosthetic fractures of the distal femur compared with non-periprosthetic fractures. The detected combination of plates together with cerclage was associated with higher complication rates. Level of evidence Level III retrospective comparative study.

Asunto(s)

RESUMEN

BACKGROUND: The Wiltse approach has been extensively employed in thoracolumbar surgeries due to its minimal muscle damage. However, in the middle and lower thoracic spine, the conventional Wiltse approach necessitates the severance of the latissimus dorsi and trapezius muscles, potentially leading to muscular injury. Consequently, we propose a modified Wiltse approach for the middle and lower thoracic vertebrae, which may further mitigate muscular damage. METHODS: From May 2018 to April 2022, 60 patients with spinal fractures in the middle and lower thoracic vertebrae (T5-12) were enrolled in this study. Thirty patients underwent surgery using the modified Wiltse approach (Group A), while the remaining 30 patients received traditional posterior surgery (Group B). The observation indices included operation time, intraoperative blood loss, incision length, number of C-arm exposures, postoperative drainage, postoperative ambulation time, discharge time, as well as preoperative and postoperative Cobb's angle, percentage of anterior vertebral body height (PAVBH), visual analog scale (VAS) Score, and Oswestry disability index (ODI). RESULTS: Compared to the traditional posterior approach, the modified Wiltse approach demonstrated significant advantages in operation time, intraoperative blood loss, length of incision, postoperative ambulation time, postoperative drainage, and discharge time, as well as postoperative VAS and ODI scores. No significant differences were observed between the two groups in terms of number of C-arm exposures, postoperative Cobb's angle, or postoperative PAVBH. CONCLUSION: We propose a modification of the Wiltse approach for the middle and lower thoracic vertebral regions, which may further minimize muscular damage and facilitate the recovery of patients who have undergone surgery in the middle and lower thoracic vertebrae.

Asunto(s)

RESUMEN

In this article, we attempted to identify risk factors affecting the loss of vertebral height and kyphosis correction on type A thoracolumbar fractures. Patients with type A thoracolumbar fractures who underwent short segments with intermediate screws at the fracture level management between 2017 and 2022 were included in this study. Clinical factors including patients' demographic characteristics (age, sex), history (smoking, hypertension and/or diabetes), value of height/kyphosis correction, the thoracolumbar injury classification and severity score (TLICS), the load sharing classification (LSC) scores and bone mineral density were collected. Correlation coefficient, simple linear regression analysis and multivariate regression analysis were performed to identify the clinical factors associated with the loss of vertebral height/kyphosis correction. Finally, 166 patients were included in this study. The mean height and kyphosis correction were 21.8% ±â€…7.5% and 9.9°â€…±â€…3.8°, respectively, the values of the loss were 6.5% ±â€…4.0% and 3.9°â€…±â€…1.9°, respectively. Simple linear regression analysis and multivariate regression analysis showed that age, value of height correction, LSC scores and bone mineral density were significantly associated with the loss of vertebral height and kyphosis correction (P < .01) We could draw the conclusion that patients with older age, lower bone mineral density, higher LSC scores and diabetes are at higher risk of vertebral height and kyphosis correction loss increase. For these patients, appropriate clinical measures such as long segment fixation, control of blood glucose, and increase of bone density must be taken to reduce the loss of correction.

Asunto(s)

RESUMEN

BACKGROUND: Ogden type V tibial tubercle avulsion fracture is an unusual type of physial injury. Thus, little is known about its mechanism of injury and treatment. The type of osteosynthesis is variable and depends on the experience of the surgeon. We commonly used cancellous screws fixation combined with tension band wiring for displaced fracture of the anterior tibial tuberosity. CASE PRESENTATION: The present manuscript describes a case of a Han nationality 13-year-old boy who presented with severe pain of the left knee, which began after landing following a high jump. He had no significant past medical history apart from a high body mass index of 30.3. Radiographs revealed that he had an unusual Ogden type V tibial tubercle avulsion fracture. He was treated by open reduction and combined fixation with cannulated screws and tension-band wiring. After 3 months, the fracture healed without any complications or knee symptoms with full range of motion. He underwent reoperation for symptomatic hardware, which was removed at 5 months after initial surgery, and returned to his prior level of sporting activity at 1 year follow-up. CONCLUSION: Our case suggests that excellent functional outcome could be achievable by open reduction with the combination of internal fixation and tension-band wiring for Ogden type V tibial tubercle avulsion fracture. This type of osteosynthesis could not only achieve anatomical reduction and stable fixation for such fractures, but also avoid further damage to the proximal tibial epiphysis, which prevents serious complications, such difference in leg length.

Asunto(s)

RESUMEN

CASE: We present a case of robot-assisted placement of 3 trans-sacral transiliac screws through a single corridor for an unstable U-type sacral fracture in a 95-year-old woman. She had persistent pain and inability to mobilize with physical therapy. At 3-month follow-up, the patient had evidence of interval healing and stable hardware and was able to return to her prior functional baseline. CONCLUSION: We demonstrate successful utilization of robotics to place 3 trans-sacral transiliac screws in a single corridor for fixation of an unstable pelvic ring injury. This technique was used to overcome challenges with visualization and implant placement.

Asunto(s)

RESUMEN

CASE: Fourteen-year-old boy presented with bilateral proximal humerus lesser tuberosity avulsions after swinging between 2 desks. Injuries were not visualized on radiographs but identified on magnetic resonance imaging. He underwent bilateral open reduction and internal fixation of the bony avulsions. Following repair, he returned to full activities, including sports, without limitations. CONCLUSION: Lesser tuberosity avulsions are rare injuries in the pediatric population that can be missed. Our case is a low energy noncontact mechanism resulting in bilateral injury, highlighting the importance of having a high index of suspicion for this diagnosis in adolescent patients with shoulder pain with normal radiographs.

Asunto(s)

RESUMEN

CASE: Odontoid fractures with atlantoaxial dislocations are rare injuries. We report a case of a 41-year-old man with a Type 2 odontoid fracture with locket facet and posterolateral dislocation. He underwent single-stage C1-C4 posterior fixation and fusion, and at 2-year follow-up, he is symptom-free without any residual pain. Follow-up radiograph and CT scan show healed odontoid fracture with posterior fusion. CONCLUSION: This case highlights successful management of a complex odontoid fracture by a single-stage posterior surgery. Closed reduction is usually unsuccessful, and open reduction using posterior approach is preferable.

Asunto(s)

RESUMEN

Plate fixation is a common treatment option for radial head fractures (RHFs). Due to the benefits of less invasiveness and fewer complications of internal fixation, the application of small-diameter headless compression screws (HCSs) to treat RHFs has become a new trend. This study aimed to compare the mechanical stability of four distinct internal fixation protocols for transversely unstable RHFs via finite element analysis. Using computed tomography data from 10 patients, we developed 40 patient-specific FE models of transversely unstable RHFs fixed by parallel, crossed, and tripod HCSs and mini-T plate (MTP). Under simulated physiological loading of the elbow joint, the construct stiffness, displacement, and von Mises stresses were evaluated and verified by a biomechanical experiment. Under shear loading, the MTP group exhibited lower construct stiffness, larger displacement, and higher Von Mises stress than the HCSs group. The stiffness of tripod HCSs was greater than parallel and crossed screw fixation techniques. There was a strong relationship between apparent bone density and construct stiffness (R = 0.98 to 0.99). In the treatment of transversely unstable RHFs, HCSs have superior biomechanical stability than MTP. The tripod technique was also more stable than parallel and crossed fixation.

Asunto(s)

RESUMEN

BACKGROUND: Anatomical reduction and stable fixation of complex tibial plateau fractures remain challenging in clinical practice. This study examines the efficacy of using 3D printing technology combined with customized plates for treating these fractures. METHODS: We retrospectively analyzed 22 patients treated with 3D printing and customized plates at the Orthopedic Department of the Central Hospital affiliated with Shenyang Medical College from September 2020 to January 2023. These patients were matched with 22 patients treated with traditional plates with similar baseline characteristics. Patients were divided into an experimental group (3D-printed models and customized plates) and a control group (traditional plates). The control group underwent traditional surgical methods, while the experimental group had a preoperative 3D model and customized plates for surgical planning. We compared baseline characteristics and recorded various indicators, including preoperative preparation time, surgical time, intraoperative blood loss, number of intraoperative fluoroscopies, hospital stay duration, fracture healing time, complications, knee joint range of motion (ROM), Rasmussen anatomical and functional scores, and HSS scores. RESULTS: All surgeries were successful with effective follow-up. The experimental group had shorter surgical time, less intraoperative blood loss, and fewer intraoperative fluoroscopies (P < 0.05). At 6 months and 1 year postoperatively, the experimental group had better knee joint HSS scores than the control group. Preoperative preparation time and total hospital stay were shorter in the control group (P < 0.05). There were no significant differences in fracture healing time and follow-up duration between groups. The experimental group showed better knee joint flexion angles (P < 0.05). Rasmussen scores showed no statistical difference between groups (P > 0.05). The incidence of complications was slightly lower in the experimental group but not significantly different. CONCLUSION: 3D printing technology combined with customized plates for complex tibial plateau fractures enables precise articular surface reduction, significantly shortens surgical time, and reduces intraoperative blood loss. This method improves knee joint function, offering a more effective treatment option.

Asunto(s)

RESUMEN

BACKGROUND: In acetabular fracture surgery, understanding the biomechanical behaviour of fractures and implants is beneficial for clinical decision-making about implant selection and postoperative (early) weightbearing protocols. This study outlines a novel approach for creating finite element models (FEA) from actual clinical cases. Our objectives were to (1) create a detailed semi-automatic three-dimensional FEA of a patient with a transverse posterior wall acetabular fracture and (2) biomechanically compare patient-specific implants with manually bent off-the-shelf implants. METHODS: A computational study was performed in which we developed three finite element models. The models were derived from clinical imaging data of a 20-year-old male with a transverse posterior wall acetabular fracture treated with a patient-specific implant. This implant was designed to fit the patient's anatomy and fracture configuration, allowing for optimal placement and predetermined screw trajectories. The three FEA models included an intact hemipelvis for baseline comparison, one with a fracture fixated with a patient-specific implant, and another with a conventional implant. Two loading conditions were investigated: standing up and peak walking forces. Von Mises stress and displacement patterns in bone, implants and screws were analysed to assess the biomechanical behaviour of fracture fixation with either a patient-specific versus a conventional implant. RESULTS: The finite element models demonstrated that for a transverse posterior wall type fracture, a patient-specific implant resulted in lower peak stresses in the bone (30 MPa and 56 MPa) in standing-up and peak walking scenario, respectively, compared to the conventional implant model (46 MPa and 90 MPa). The results suggested that patient-specific implant could safely withstand standing-up and walking after surgery, with maximum von Mises stresses in the implant of 156 MPa and 371 MPa, respectively. The results from the conventional implant indicate a likelihood of implant failure, with von Mises stresses in the implant (499 MPa and 1000 MPa) exceeding the yield stress of stainless steel. CONCLUSION: This study presents a workflow for conducting finite element analysis of real clinical cases in acetabular fracture surgery. This concept of personalized biomechanical fracture and implant assessment can eventually be applied in clinical settings to guide implant selection, compare conventional implants with innovative patient-specific ones, optimizing implant designs (including shape, size, materials, screw positions), and determine whether immediate full weight-bearing can be safely permitted.

Asunto(s)

RESUMEN

OBJECTIVE: To retrospectively analyze and assess the long-term effectiveness of robotic navigation and traditional closed reduction internal fixation in the treatment of Delbet type II femoral neck fracture in children. METHODS: A total of fifty-five patients diagnosed with pediatric Delbet type II femoral neck fracture, who were admitted to Foshan Hospital of Traditional Chinese Medicine between January 2018 and June 2022, were included in this study. Among them, 22 cases of nailing under robotic navigation were set as the observation group, and 33 cases of nailing under fluoroscopy of the C-arm machine were set as the control group. All patients had their femoral neck fractures closed and repositioned first. After confirming the satisfactory fracture repositioning under the fluoroscopic view of the C-arm machine, internal fixation was performed by inserting hollow compression screws in the corresponding surgical way.A comparative analysis was conducted between the two groups to assess the disparity in the amount of X-ray exposure during surgery, the number of guide pins inserted, and the duration of the surgical procedure. The quality of comparative fracture reduction was assessed according to the Haidukewych criteria on the first postoperative hip X-ray, and the parallelism and distribution of the comparative screws were measured. The incidence of hip function and postoperative complications according to the Ratliff criteria were evaluated between each of the subgroups at the final follow-up. RESULTS: Comparison of general information, operation duration, and quality of fracture reduction between the two groups failed to reveal statistically significant results (P > 0.05). The observation group had a lower number of X-ray exposures and guide pin placements compared to the control group, and this difference was statistically significant (P < 0.05).At the last follow-up, the observation group exhibited superior screw parallelism and distribution, as well as hip joint function, compared to the control group, and this difference was statistically significant (P < 0.05). The incidence of complications in the observation group was lower than that in the control group; however, the difference was not statistically significant (P > 0.05). CONCLUSION: Closed reduction and internal fixation under orthopedic robot navigation can achieve better long-term efficacy in treating Delbet type II femoral neck fracture in children.

Asunto(s)