Search Results (24)

Background: Facial asymmetry affecting the mandibular contour may significantly impact facial harmony even in patients with stable occlusion. Although orthognathic surgery remains the standard for skeletal correction, it carries substantial morbidity. In selected cases, contour-focused approaches can achieve meaningful esthetic improvement with reduced surgical burden. Objective: To describe the virtual surgical planning (VSP) workflow and clinical outcome of a unilateral Wing osteotomy for mandibular contour asymmetry. Case presentation: A 24-year-old woman presented with left-sided mandibular contour deficiency and facial asymmetry, despite stable Class I occlusion and preserved function. VSP with contralateral mirroring guided the design of the osteotomy and fabrication of a stereolithographic model and patient-specific cutting guide. Surgery was performed through a tunnelized mandibular approach using a 702 bur and reciprocating saw. Fixation was achieved with pre-bent 2.0 plates adapted to the 3D model, and Bio-Oss Collagen was interposed within the osteotomy gap. Occlusion and mental nerve function were preserved. Results: Postoperatively, the patient demonstrated improved facial symmetry, uneventful healing, preserved long-term neurosensory function, and high esthetic satisfaction. Conclusions: Unilateral Wing osteotomy guided by VSP and patient-specific instrumentation is a predictable, minimally invasive alternative to bimaxillary orthognathic surgery with genioplasty in selected patients presenting contour-focused asymmetry and stable occlusion. This case highlights a rare, underreported application of the technique. Full article

A six-year-old, neutered male Pomeranian weighing 4.25 kg was presented with a two-year history of non-weight-bearing lameness of the left thoracic limb following an untreated traumatic olecranon fracture. Orthopedic examination revealed markedly reduced elbow joint range of motion and muscle atrophy. Radiographs demonstrated a distinct fracture line with proximolateral displacement of the olecranon fragment. Preoperative computed tomography (CT) and three-dimensional (3D) reconstruction were used to establish the surgical plan and to pre-contour a locking plate. Surgical treatment was performed in sequential steps, including removal of scar tissue, reopening of the bone marrow channel, and internal fixation. Considering the compromised biological environment of a chronic non-union, a bioactive graft composed of porous leaf-stacked structure (LSS) polycaprolactone particles incorporating recombinant human bone morphogenetic protein-2 (rhBMP-2) and mesenchymal stem cells (MSCs) was applied in combination with plate-screw fixation. The patient showed progressive improvement after surgery, achieving full weight-bearing and restoration of elbow joint motion comparable to the contralateral side. Follow-up radiographs and CT confirmed fracture union, and the radiolucency of the LSS scaffold enabled precise monitoring of bone healing. This case highlights the potential utility of combining patient-specific surgical planning with sustained delivery of rhBMP-2 and MSCs using LSS particles for the management of chronic non-union fractures in small animals. Full article

Objectives: Operative fixation of displaced midshaft clavicle fractures has become increasingly the more acceptable choice of care in recent years, based on evidence supporting its effectiveness. However, this practice presents challenges due to the complex S-shaped morphology of the clavicle and its subcutaneous location. Despite the introduction of anatomically pre-contoured plates, achieving optimal implant-to-bone fit remains difficult, prompting the development of newer plate generations. The aim of this study was to compare the hardware removal rates of second-generation 2.7 mm thinner plates (SGPs) with those of first-generation 3.5 mm plates (FGPs). Methods: A retrospective comparative cohort study was conducted at a level one trauma center. A total of 187 patients received FGPs, and 67 received SGPs, both positioned on the superior bone surface. All surgeries were performed by fellowship-trained surgeons, and patients were followed for at least one year. Data were extracted from medical records and the PACS system. Results: The patients’ demographics (age: 32.86 vs. 33.14 years; gender: 16.85% vs. 14.92% female) and fracture type (AO/OTA) were similar between the two groups. The rate of implant removal (20.1% vs. 20.9%) did not differ significantly between groups. Complications included nonunion (1.6% vs. 1.7%, statistically not significant) and infection (three cases in the FGP group, none in the SGP group). Conclusions: Despite the high success rate of clavicle fixation procedures, the superior clavicular plate removal rate remains significant, regardless of the implant design. Full article

The iron and steel industry is a major emitter of carbon. In the context of China’s dual-carbon goals, hydrogen-based reduction ironmaking technology has garnered unprecedented attention. It is considered a crucial approach to reducing carbon dioxide emissions in the steel sector and facilitating the realization of carbon neutrality. This work conducted isothermal thermogravimetric analysis on limonite ore in a N₂/H₂ atmosphere. The influences of reduction temperature, particle size, and hydrogen partial pressure on the hydrogen reduction reaction process of limonite were investigated. Based on the principles of isothermal thermal analysis kinetics and the unreacted core model for flat-plate particles, the mechanism function and kinetic parameters for the reduction of limonite particles were determined. The research results show that the hydrogen reduction process of limonite ore is influenced by multiple factors, including temperature, hydrogen partial pressure, and particle size. Increasing the reduction temperature and hydrogen partial pressure can significantly speed up the reduction reaction rate and enhance the degree of reduction. The kinetic parameters for the hydrogen reduction of limonite particles were obtained as follows: the reaction activation energy was 44.738 kJ·mol⁻¹, the pre-exponential factor was 31.438 m·s⁻¹, and the rate constant for the hydrogen reduction of limonite was $k=31.438\times e^{-{\displaystyle \frac{44.738\times 1000}{RT}}}\mathrm{m}\cdot {\mathrm{s}}^{-1}$. In addition, contour maps were plotted to predict the reaction time and reaction temperature required for a complete reduction of limonite particles of different sizes to iron (Fe) particles under varying hydrogen partial pressures. The research findings can serve as a scientific basis for optimizing hydrogen-based reduction ironmaking technology in the iron and steel industry and achieving carbon neutrality goals. Full article

Monteggia fractures represent complex injuries requiring careful assessment and surgical intervention. This case report presents a rare variation of a Bado type I Monteggia fracture–dislocation that resembles features from the Jupiter subclassification type IID. A 39-year-old male sustained a high-energy injury while riding an all-terrain vehicle, resulting in a proximal segmental ulnar shaft fracture with anterior radial head dislocation. Open reduction and internal fixation (ORIF) of the ulna using a pre-contoured proximal ulna low-contact dynamic compression plate (LC-DCP) successfully restored alignment, leading to spontaneous reduction of the radial head. The postoperative course was uneventful, with satisfactory healing and functional recovery. This case underscores the importance of meticulous ulnar reconstruction in Monteggia fracture–dislocations and contributes to the limited literature on anterior radial head dislocation patterns. Full article

Postoperative ulnar neuropathy is a common complication in patients undergoing surgery for distal humerus fractures, particularly when open reduction and internal fixation (ORIF) is performed. Objectives: This study aims to compare the rates of ulnar nerve neuropathy following classic in situ decompression versus ulnar nerve subcutaneous anterior transposition. Methods: A retrospective study was conducted, including 51 patients treated for distal humerus fractures with precontoured locking plates in our institution between 2009 and 2023, according to specific inclusion and exclusion criteria. Age, sex, ulnar neuropathy, range of motion (ROM), complications, surgical approach, and Mayo Elbow Performance Score (MEPS) were evaluated. Ulnar nerve function was graded according to modified McGowan classification. Results: Ulnar neuropathy was observed in 17 (33.3%) patients, with a higher risk in those who underwent anterior ulnar nerve transposition compared to in situ decompression (58% vs. 26%, p = 0.042). In the modified McGowan classification, 14 patients had grade 1 and 3 had grade 2 neuropathy. The overall complication rate was 49%, and the functional outcomes according to the MEPS scale showed a mean score of 81.6 (SD 17.29). The mean flexion–extension was 100.56°, and 94% of patients retained complete pronosupination. Conclusions: Our results demonstrate that routine intraoperative ulnar nerve transposition should not be performed for these fractures. Full article

Study design: A retrospective case series. Objective: The management of acute complex maxillofacial trauma is challenging. The intricate maxillofacial anatomy coupled with the significant functional and aesthetic repercussions of traumatic facial injuries necessitate meticulous preoperative preparation and operative precision to minimize patient morbidity. The severe displacement of bone fragments, abnormal occlusion, comminution, and the involvement of multiple skeletal subsites further complicate the restoration of premorbid function and appearance. While previously recognized as a valuable tool for managing oncologic defects, orthognathic surgery, and for the correction of secondary deformities following maxillofacial trauma, virtual surgical planning (VSP) has now emerged as a viable tool for treating select patients following acute complex maxillofacial trauma. Methods: A retrospective chart review of all the complex facial trauma patients treated using VSP services over a 21-month period. Results: Multiple VSP services were used in the primary repair of complex facial trauma, with occlusal splints, pre-contoured plates, and 3D printed models being utilized most frequently. Conclusions: Our experience with VSP for primary maxillofacial trauma repair has helped us to identify specific indications for the use of VSP in this setting. Full article

The human clavicle’s unique S-shaped, three-dimensional structure complicates fracture management. This study evaluated the anatomical conformity of pre-contoured anatomical plates using 3D-printed clavicle models. CT scans from 30 patients (15 males and 15 females) were used to create these models. Three brands of distal clavicle plate systems (Acumed, Synthes, and Arthrex) were tested for fit. Measurements included the distance from the distal end of the clavicle to the plate’s lateral end, the gap between the clavicle and the plate, and the overhang distance. Results showed significant differences in clavicle length between sexes, with men having a mean length of 156.1 ± 7.6 mm and women 138.4 ± 4.3 mm, both with normal distribution (p > 0.05). The mean lateral distance was 7.9 ± 1.7 mm, and the mean medial gap was 3.6 ± 3.0 mm, showing no significant differences between products or sexes. The mean overhang distance was 5.8 ± 4.6 mm, with larger values in women for the Acumed (p = 0.037) and Arthrex (p = 0.000) plates. Overall, pre-contoured plates exhibited notable discrepancies, especially in shorter clavicles. Full article

In small-breed dogs with concurrent cranial cruciate ligament rupture (CCLR) and medial patellar luxation (MPL), correcting both disorders is are essential for restoring normal gait. However, the previously described surgical treatment, using two osteotomy technique, poses a high risk of fracture and instability. Addressing CCLR and MPL with a single osteotomy and implant was considered superior to the conventional method. Therefore, a pre-contoured modified tibial plateau leveling osteotomy (PCM–TPLO) plate facilitating medial shifting of the proximal tibia was developed. We compared postoperative alignment and strength between this novel plate group and a conventional tibial plateau leveling osteotomy (TPLO) plate group using eight small-breed dog cadavers each. Additionally, we investigated the potential of the novel plate as an alternative to tibial tuberosity transposition. Postoperative alignment and strength were assessed through radiographs and mechanical testing. Measurements including tibial plateau angle, mechanical medial proximal tibial angle, and number of screws within the joint were also analyzed. There were no significant differences in all measured parameters. For the novel plate, the medial displacement ratio of the proximal tibia was confirmed to be approximately 30%, and the result was thought to be appropriate. These findings suggest that the PCM–TPLO plate could be a promising alternative for treating concurrent CCLR and MPL in small-breed dogs. Full article

(1) Background: Due to the unique structural and functional characteristics of the forelimb in cats, fractures of the radius and ulna are best repaired using internal fixation and stabilization in accordance with AO principles. This study presents the results of reduction of 42 cadaveric comminuted feline radial fractures reduced by minimally invasive plate osteosynthesis (MIPO). (2) Methods: Radius fractures were created on 21 pairs of forelimbs with intact bones. MIPO was then performed using two locking bone plates pre-contoured on 3D-printed bone models of the antebrachium of a male and a female cat. Pre- and postoperative radiographs were taken, and radius length and anatomical lateral distal radial angle (aLDRA) were measured. (3) Results: All fractures were classified as complex diaphyseal fractures of the radius. The radial bone length did not change significantly after surgery (F_1,18 = 0.01, p = 0.933). However, the aLDRA was modified after surgery (F_1,18 = 7.51, p = 0.013), but this change was only observed in females, in whom the aLDRA was significantly reduced (p = 0.035) compared to the value determined by the shape of the plate. In males, the pre- and postoperative aLDRA values were similar (p = 0.824). In 40 cases, alignment, adjacency of bone fragments, and apparatus were judged to be satisfactory. In two cases, the plate was fixed to the proximal radius and distal ulna due to misidentification of the distal radius. In both cases, revision surgery and correct fixation of the radius gave proper alignment, adjacency, and apparatus. (4) Conclusion: A pre-contoured plate on a 3D-printed model of the male and female domestic cat antebrachium was suitable for the reduction and stabilization of comminuted radial fractures in a cohort of domestic cat cadavers without the need to print individual antebrachial bone models for each patient. Full article

(1) Background: Anatomically pre-contoured plates usually require only minimal or even no intraoperative contouring. For complex cases, such plates also assist the surgeon as an anatomical template during fracture reduction. In this study, we present our experience of using a 3D printing technology for the treatment of bicondylar humeral fractures in feline cadavers. (2) Methods: Surgeries were performed on 15 pairs of front limbs amputated at the scapula. The limbs were obtained from 15 adult cats without obvious pathology of the skeleton. After flexion of the elbow and subperiosteal elevation of the anconeus muscle, the humeral Y-T fractures were created using a bone chisel and mallet. A custom-made anatomically pre-contoured interlocking plate was used to reduce and stabilise the medial aspect of the humeral condyle to the humeral diaphysis. After reduction of the humeral condyle, a positional locking screw was then inserted from the medial to the lateral side and a straight 2.4/2.7 interlocking bone plate was used to stabilise the lateral part of the condyle to the humeral diaphysis. (3) Results: The length of the humerus ranged from 98.2 to 107.0 mm and did not differ significantly between the left and right bone. The diameter of the isthmus of the humeral condyle ranged from 5.2 to 5.5 mm and did not differ significantly between the left and right bone. In all 30 limbs, bicondylar fracture was accompanied by epicondylar comminution. In 7/30 limbs (4 left, 3 right) the fracture of the humeral shaft was also present. In the left limbs, the postoperative articular surface defect of the humeral condyle was small (<1 mm) in 11/15 cases, moderate (1–2 mm) in 2/15 cases and large (>2 mm) in 2/15 cases in which the condylar screw was incorrectly inserted. In the right limbs, the postoperative articular surface defect of the humeral condyle was small (<1 mm) in 14/15 cases and moderate (1–2 mm) in 1 case. (4) Conclusions: 3D printing and the technology of metal powder sintering offers a wide range of possibilities for the development of new surgical implants. The anatomically pre-contoured bone plate appears to be a valuable tool in the reduction and stabilisation of Y-T humeral fractures in adult domestic cats weighing 3.0 to 4.5 kg. Full article

We report our experience of preoperative plate contouring for periarticular fractures using three-dimensional printing (3DP) technology and describe its benefits. We enrolled 34 patients, including 11 with humerus midshaft fractures, 12 with tibia plateau fractures, 2 with pilon fractures, and 9 with acetabulum fractures. The entire process of plate contouring over the 3DP model was videotaped and retrospectively analyzed. The total time and number of trials for the intraoperative positioning of precontoured plates and any further intraoperative contouring events were prospectively recorded. The mismatch between the planned and postoperative plate positions was evaluated. The average plate contouring time was 9.2 min for humerus shaft, 13.8 min for tibia plateau fractures, 8.8 min for pilon fractures, and 11.6 min for acetabular fractures. Most precontoured plates (88%, 30/34) could sit on the planned position without mismatch. In addition, only one patient with humerus shaft fracture required additional intraoperative contouring. Preoperative patient specific periarticular plate contouring using a 3DP model is a simple and efficient method that may alleviate the surgical challenges involved in plate contouring and positioning. Full article

Background and Objectives: Distal femoral fracture is a severe injury that makes surgery challenging, particularly comminuted fractures in the supracondylar region. This study aimed to evaluate the outcomes of distal femoral fracture treated with the application of an intramedullary fibular allogenic bone strut in open reduction and internal fixation (ORIF) with precontoured locking plates in patients over 50 years of age. Materials and Methods: The study retrospectively enrolled 202 patients over 50 years of age with traumatic comminuted distal femoral fracture (AO/OTA 33-A3, 33-C2 and 33-C3) treated with ORIF with a locking plate from January 2016 to December 2019. The two groups were divided into patients who received an intramedullary allogenic bone strut and those who did not. Patients were followed for at least 1 year, with their function scores and radiographic data recorded. Results: A total of 124 patients were recruited, comprising 60 men and 64 women with an average age of 62.4 ± 8.5 years. The 36 patients who had received an intramedullary allogenic fibular bone strut reported lower postoperative pain scores at 1 month and lower postoperative Knee Society Scores (KSS) at 3 months than the control group. The application of an intramedullary allogenic fibular bone strut appeared to be significantly correlated with better 3-month postoperative KSS. Conclusions: The ORIF of distal femoral comminuted fracture with an intramedullary allogenic fibular bone strut can reduce pain and improve knee function in the early stages of postoperative rehabilitation and may reduce the time to union in patients over 50 years of age. Full article

Background and Objectives: The TomoFix anatomical plate was developed to improve plate position, proximal screw direction, and post-correction tibial contouring. The purpose of this study was to compare postoperative configurations between the TomoFix anatomical plate and the TomoFix conventional plate. It was hypothesized that the new modified plate provides a better fixative coaptation than the conventional plate. Materials and Methods: A total of 116 cases (112 patients) were enrolled in this study from March 2015 to February 2021. Among them, 63 patients underwent surgery using the TomoFix conventional plate, and 53 underwent surgery using the TomoFix anatomical plate. The radiographic outcomes, including the hip–knee–ankle (HKA) angle, medial proximal tibial angle (MPTA), tibial slope, plate angle, proximal screw angles, and plate-to-cortex distance at #1 hole (just below the osteotomy site) were compared between the two groups. Results: Patients with the TomoFix anatomical plate showed similar results in terms of the pre- and postoperative HKA angle, MPTA, and tibial slope. The TomoFix anatomical group showed a significantly greater plate angle (39.2° ± 8.1° vs. 31.7° ± 7.0°, p < 0.001) and less screw angles, indicating that the TomoFix anatomical plates allowed a more posterior plate position than the conventional plate. The plate-to-cortex distance was significantly less in the TomoFix anatomical group than in the TomoFix conventional group (p < 0.001). Conclusion: The TomoFix anatomical plate showed a more posteromedial plating position, better proximal screw direction to the lateral hinge, and improved post-correction tibial contour compared to the TomoFix conventional plate. Full article

Background. Preoperative planning and 3D printing can be used to treat pelvic bone fractures using pre-contoured surgical plates, in particular complex, comminuted fractures involving the acetabulum and quadrilateral plate. The aim of the study was to develop a Fast-Track-Protocol (fast track methodology) for creating 3D anatomical models, that could be used to shape surgical plates, using open-source software and budget 3D printers. Such a ‘low-budget’ approach would allow a hospital-based multidisciplinary team to carry out pre-surgical planning and treat complex pelvic fractures using 3D technology. Methods. The study included 5 patients with comminuted pelvic fractures. For each patient, CT (computed tomography) data were converted into two 3D models of the pelvis-injured side and mirrored model of the contralateral, uninjured hemipelvis. These models were 3D printed and used as templates to shape surgical plates. Results. A Fast-Track-Protocol was established and used to successfully treat 5 patients with complex, comminuted fractures of the pelvis. Conclusion. Using the Fast-Track-Protocol it was possible to prepare 3D printed models and patient-specific pre-contoured plates within 2 days of hospital admittance. Such an approach resulted in better surgical technique and shorter operative times, while incurring relatively low costs. Full article