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Distal radial and ulnar fractures in miniature- and toy-breed dogs are associated with high rates of delayed union, non-union, and refracture. This retrospective observational study evaluated the outcomes of simple distal radial and ulnar fractures treated by open reduction and internal fixation using a locking plate in a non-rigid configuration. Ten fractures in eight dogs weighing less than 5 kg were included. Cases were selected according to predefined biomechanical construct criteria, including a plate bridge ratio > 0.7, plate span ratio > 10, plate working length > 40% of the plate length, and screw density < 0.6. The median radiographic follow-up was 224 days (range, 46–408 days). Radiographic bone healing was achieved in all cases, with a mean time to union of 53 days (range, 28–113 days), and healing occurred faster in skeletally immature dogs. Indirect bone healing with callus formation was observed in 7 of 10 fractures. Minor postoperative complications occurred in three cases and resolved with local treatment. No implant failures or refractures associated with previous screw holes were observed. A reduction in ulnar thickness was identified in evaluable cases, although this finding remained stable during follow-up and did not appear clinically relevant. These findings suggest that locking plate fixation in a non-rigid configuration provides reliable bone healing with a low complication rate in simple distal radial and ulnar fractures of miniature- and toy-breed dogs.

Despite numerous available treatment strategies, the management of complex proximal humeral fractures remains demanding. Impaired bone quality and considerable comorbidities pose special challenges in the growing aging population. Complications after operative treatment are frequent, in particular loss of reduction with varus malalignment and subsequent screw cutout. Locking plate fixation has become a standard in stabilizing these fractures, but surgical revision rates of up to 25% stagnate at high levels. Therefore, it seems of utmost importance to select the right treatment for the right patient. This article provides an overview of available classification systems, indications for operative treatment, important pathoanatomic principles, and latest surgical strategies in locking plate fixation. The importance of correct reduction of the medial cortices, the use of calcar screws, augmentation with bone cement, double-plate fixation, and auxiliary intramedullary bone graft stabilization are discussed in detail.

Objective Calcaneal fracture fixation remains a challenging procedure in orthopedics, with computational tools increasingly aiding in the optimization of preoperative planning. To compare the biomechanical stability of intramedullary fixation and locking plate fixation for Sanders II and III calcaneal fractures by three-dimensional (3D) finite element analysis and to provide a theoretical basis for clinical application. Methods The Computed Tomography (CT) images were segmented using Mimics software (Materialise NV, Belgium) to identify the region of interest based on threshold segmentation. The 3D morphology was reconstructed using Mimics 10.01 software. Subsequently, Geomagic2012 software (3D Systems, USA) was employed to remove noise points, sharp corners, and scattered points, achieving a smooth surface map. This map was saved in Initial Graphics Exchange Specification (IGES) format and imported into Solidworks (Dassault Systèmes, France) for model assembly and volume model construction. A three-dimensional finite element model of Sanders II/III, calcaneal fractures with intramedullary fixation and locking plate fixation, was established and analyzed by linear finite element analysis. The forced displacement, stiffness, and stress distribution of the two fixation methods were calculated. In addition, the three-dimensional model was tested using a compression mechanical experiment. Results Comparing fixation methods for Sander II and III fractures, the force-displacement curve of the intramedullary nail group aligned more closely with standards. Under axial compression, bone stress was highest with the Sanders II locking plate and lowest with the intramedullary nail. Across models, the intramedullary nail consistently exhibited slightly higher stress than the locking plate. The intramedullary nailing group model of the overall stiffness was slightly greater than the locking plate. By comparing the compressive mechanical test performance of the two fixation methods, it was found that the plate fixation group had an abnormal load until 7092.895 N, which was 1.5 times more than the load of the intramedullary nail. Conclusion Both intramedullary fixation and locking plate fixation for Sanders II and III calcaneal fractures have certain biomechanical stability, and locking plate fixation has potential application value in clinical practice.

Background This study investigated the impact of higher interfragmentary compression force (IFCF) on the stability of locking plate fixation in lateral tibial plateau fractures. Methods Biomechanical experiments and finite element analysis (FEA) were employed to compare the performance of the AO cancellous lag screw (AOCLS) and a newly developed combined cancellous lag screw (CCLS). Results The results demonstrated that the CCLS provided a higher IFCF without the risk of over-screwing, significantly improving fixation stability. High IFCF markedly increased the initial axial stiffness, allowing for earlier weight-bearing in patients. Additionally, the FEA showed that increased IFCF reduced the peak von Mises stress on implants and the peak equivalent elastic strain on the lateral fragment, thereby enhancing overall structural stability. Conclusions These findings suggested that the CCLS, with its superior IFCF and reduced risk of over-screwing, was a promising option for improving fixation stability in lateral tibial plateau fractures. This improvement could facilitate early rehabilitation, minimise complications, and provide better clinical outcomes. These results provide strong scientific evidence for the clinical use of CCLS.

‌ Objective This finite element analysis compared the biomechanical performance of two surgical approaches for Neer Type II distal clavicle fractures: isolated locking plate fixation versus locking plate fixation combined with anatomical double-bundle coracoclavicular ligament reconstruction. Methods A three-dimensional finite element model of the shoulder was developed from the CT scan of a 30-year-old healthy male. Three conditions were simulated: an intact joint (Group A, control), a fractured joint fixed with a locking plate alone (Group B), and a fractured joint fixed with a locking plate plus ligament reconstruction (Group C). Materials were assigned linear elastic properties. Under a simulated 90° arm abduction load, we analyzed the distribution of Von Mises stress, the displacement of the distal clavicular fracture fragment, and the subacromial contact pressure. Results Compared to Group B, Group C exhibited a more favorable biomechanical profile. The combined technique reduced the peak Von Mises stress at the distal clavicle by 37% (44.28 MPa vs. 70.12 MPa). Fragment displacement decreased by 42% in the horizontal plane (4.52 mm vs. 7.76 mm) and by 45% vertically (2.87 mm vs. 5.23 mm). The peak subacromial pressure was also lower in Group C (980 kPa vs. 1520 kPa). Conclusion Within the constraints of this finite element model, augmenting plate fixation with anatomical coracoclavicular ligament reconstruction reduced stress concentration and improved fragment stability in Neer type II fractures, suggesting a biomechanical advantage over plating alone. These computational results support the continued clinical investigation of this combined technique.

BackgroundThe aim of this study was to identify the effect of screw length on predictions of fixation failure in three-part proximal humeral fractures using a finite element-based osteosynthesis modelling toolkit.MethodsA mal-reduced unstable three-part AO/OTA 11-B3.2 fracture with medial comminution was simulated in forty-two digitally processed proximal humeri covering a spectrum of bone densities and fixed with the PHILOS plate using three distal and six proximal locking screws. Four test groups were generated based on the screw tip to joint surface distance (TJD), with all proximal screws being shortened from 4 mm TJD to be 8, 12 or 16 mm TJD. Average bone strains around the screw tips, correlating with biomechanical cyclic cut-out-type failure, were evaluated in three physiological loading protocols representing simple shoulder motions. Six further groups were tested, where five of the proximal screws were inserted to 4 mm TJD and the sixth screw to 8 mm TJD.ResultsExponential increases in the predicted risk of fixation failure were seen with increased tip-to-joint distances (p < 0.001). When one of the proximal screws was placed 8 mm from the joint, with the remaining five at 4 mm distance, significant increases (p < 0.001) were registered in the strains around the screw tips in all except the two superior screws. This effect was maximal around the calcar screws (p < 0.001) and for lower density samples (p < 0.001).ConclusionsThese results suggest that longer screws provide reduced risk of cut-out failure, i.e. distalisation and/or varisation of the head fragment, and thus may decrease failure rates in proximal humeral fractures treated with angular stable plates. These findings require clinical corroboration and further studies to investigate the risk of screw perforation.

IntroductionThe incidence of patella fracture is statistically low (0.5–1.5%) compared to other fractures of the extremities [Patella fractures 76(10):987–997, 2005]. In the latter research, patella fractures if treated surgically present an overall inferior functional outcome. Little is known about the influence of the postoperative patella height on the clinical outcome. Therefore, the aim of our study was to analyse the influence of the patella height on the patients’ functional outcome after surgery.MethodsIn this retrospective study the in-house trauma register of our level I University trauma center was screened for patients suffering patella fractures treated surgically. Patella height of the same patients was evaluated on lateral X-rays using the Insall–Salvati Ratio (ISR). The patients’ X-rays were analyzed at two time points for the ISR, whereas group A presents ISR data right after surgery and group B data at the latest follow up (minimum 6 weeks). The change of mean ISR at both time points was tested for significance. The functional outcome was measured by the “Munich Knee Questionaire” (MKQ). These MKQ results of different patella heights and fracture types were compared.ResultsThe screening of our in-house trauma register revealed 375 patients between the years 2003 and 2016. Out of these 54 patients (34f, 20 m) were enrolled. In detail the follow-up time for ISR between group A and B accounted for a mean of 503.8 ± 655.7 days. The MKQ was assessed at a mean of 1367.0 ± 1042.8 days after surgery. According to the AO-classification 10% AO.34 type B and 90% AO.34 type C fractures were found. Group A showed in 9.1% a patella baja and in 27.3% a patella alta compared to group B presenting 20.0% patella baja and 14.5% patella alta. There was no significant difference in functional outcome referring to the MKQ in patella alta (MKQ 69.0% ± 18.2) or baja (MKQ 67.1% ± 17.9) (p = 0.9). No significant functional difference between AO34.type B (MKQ 74.5% ± 11.0) and AO34.type C fractures (MKQ 64.0% ± 15.0) resulted (p = 0.1).ConclusionOur results demonstrate that different postoperative patella heights apparently do not influence the functional outcome in the short follow-up.

Objective To compare the efficacy of K-wire-assisted positioning versus conventional freehand palpation in improving intraoperative efficiency (fluoroscopy frequency, operative time, and blood loss) for PHILOS plate placement in elderly patients with proximal humeral fractures. Methods This retrospective study included 44 patients aged > 60 years with Neer three- or four-part proximal humeral fractures treated with PHILOS plate fixation via deltopectoral approach (January 2021–June 2024). Patients were divided into freehand palpation (n = 21) and K-wire-assisted (n = 23) groups based on intraoperative technique. Primary outcomes included number of intraoperative fluoroscopies, operative time, and blood loss. Secondary outcomes were postoperative complications and Constant-Murley Score (CMS) at 6 months. Results Follow-up was completed in 37 patients (84.1%). The K-wire group required significantly fewer fluoroscopies (10.00 ± 1.41 vs. 14.61 ± 4.74 times, p  = 0.001), shorter operative time (97.55 ± 7.89 vs. 112.25 ± 7.40 min, p  = 0.036), and less blood loss (218.26 ± 40.75 vs. 288.33 ± 46.19 mL, p  = 0.001) than the freehand group. No significant differences were found in complication rates (10.5% vs. 27.8%, p  = 0.181) or 6-month CMS (76.95 ± 7.98 vs. 76.44 ± 8.68, p  = 0.855). Conclusion K-wire-assisted positioning improves intraoperative efficiency by reducing radiation exposure, operative time, and blood loss without compromising functional outcomes or increasing complications. This technique may be particularly valuable for less-experienced surgeons.

Purpose Achieving and maintaining an optimal reduction in partially or fully displaced intra-articular fractures, specifically Type C distal radius fractures, can present challenges. This study aims to retrospectively evaluate and summarize a method utilizing multi-directional temporary Kapandji technique in combination with the volar locking plate fixation for these fractures. Method The study involved 15 patients diagnosed with Type C distal radius fractures who underwent surgery between January 2024 and April 2024. The procedure incorporated a multi-directional temporary Kapandji technique, followed by stable osteosynthesis using a volar locking plate system. The functional outcomes were assessed after 4 (2–6) months of follow-up using the modified Mayo wrist scoring system (MMWS). The MMWS is a rating system used to evaluate wrist function and pain, including pain, motion, grip strength. Results All the patients incision healed within 2 weeks. All the fractures had uneventful union within 8–12 weeks. Based on the modified Mayo wrist scoring (MMWS) system, most patients showed good to excellent functional recovery. Conclusion This reduction method proved to be both simple and replicable, enabling satisfactory alignment with minimal force. The volar locking plate system provided rigid and stable fixation.

Locked plating of proximal humerus fractures (PHF) is associated with high failure rates (15–37%). Secondary screw perforation is a prominent mode of failure for PHF and typically requires reoperation. The anatomical fracture reduction is an essential factor to prevent fixation failure. However, recent studies indicate that the risk of secondary screw perforation may increase if the articular surface is perforated during predrilling of the screw boreholes (overdrilling). This study aimed to determine whether overdrilling increases the risk of secondary screw perforation in unstable PHF. Nine pairs of human cadaveric proximal humeri were osteotomized to simulate a malreduced and highly unstable 3-part fracture (AO/OTA 11 B1.1), followed by their assignment to two study groups for overdrilling or accurate predrilling in paired design, and fixation with a locking plate. Overdrilling was defined by drilling the calcar screw’s boreholes through the articular surface. All humeri were cyclically loaded to screw perforation failure. Number of cycles to initial screw loosening and final perforation failure were analysed. The accurately predrilled group revealed a significantly higher number of cycles to both initial screw loosening (p < 0.01) and final screw perforation failure (p = 0.02), compared to the overdrilled one. This is the first study reporting that drilling to the correct depth significantly increases endurance until screw perforation failure during cyclic loading after locked plating in a highly unstable PHF model. Prevention of overdrilling the boreholes could help reduce failure rates of locked plating. Future work should investigate the prevalence and consequences of overdrilling in clinics.