A Novel Implant for Superior Pubic Ramus Fracture Fixation-Development and a Biomechanical Feasibility Study.

Background and Objectives: Pubic ramus fractures are common in compound pelvic injuries known to have an increased rate of morbidity and mortality along with recurrent and chronic pain, impeding a patient's quality of life. The current standard treatment of these fractures is percutaneous screw fixation due to its reduced risk of blood loss and shorter surgery times. However, this is an intricate surgical technique associated with high failure rates of up to 15%, related to implant failure and loss of reduction. Therefore, the aim of this biomechanical feasibility study was to develop and test a novel intramedullary splinting implant for fixation of superior pubic ramus fractures (SPRF), and to evaluate its biomechanical viability in comparison with established fixation methods using conventional partially or fully threaded cannulated screws. Materials and Methods: A type II superior pubic ramus fracture according to the Nakatani classification was created in 18 composite hemi-pelvises via a vertical osteotomy with an additional osteotomy in the inferior pubic ramus to isolate the testing of three SPRF fixation techniques performed in 6 semi-pelvises each using either (1) a novel ramus intramedullary splint, (2) a partially threaded ramus screw, or (3) a fully threaded ramus screw. Results: No significant differences were detected among the fixation techniques in terms of initial construct stiffness and number of cycles to failure, p ≥ 0.213. Conclusion: The novel ramus intramedullary splint can be used as an alternative option for treatment of pubic ramus fractures and has the potential to decrease the rate of implant failures due to its minimally invasive implantation procedure.

The Possibilities of Personalized 3D Printed Implants-A Case Series Study.

Background and Objectives: Following the most recent software and 3D printing developments, the use of personalized 3D printed orthopedic implants for treatment of complicated surgical cases has gained more popularity. Today, orthopedic problems that cannot be solved with standard implants may be effectively addressed using personalized prostheses. The aim of this study is to present the designing, modeling and production stages of four different personalized 3D printed prostheses and their application in clinical cases of patients who underwent treatment in various anatomical locations with a precisely specified indication for implantation. Materials and Methods: Based on computed tomography scanning, personalized 3D printed prostheses were designed, produced and used in four patients within a period of three to five days after injury or admission. Results: Early term follow-ups demonstrated good to excellent results. Conclusions: Personalized 3D printed prostheses offer an opportunity for a treatment of choice and provide good anatomical and functional results, shortened surgical time, less complications, and high satisfaction in patients with appropriate indications. The method should be considered primarily for patients with large bone defects, or such indicated for resection. Personalized 3D printed prostheses have the potential to become more common and beneficial in the future.

Single-Stage Externalized Locked Plating for Treatment of Unstable Meta-Diaphyseal Tibial Fractures.

(1) Background: Unstable meta-diaphyseal tibial fractures represent a heterogeneous group of injuries. Recently, good clinical results have been reported when applying a technique of externalized locked plating in appropriate cases, highlighting its advantage in terms of less additional tissue injury compared with conventional methods of fracture fixation. The aims of this prospective clinical cohort study were, firstly, to investigate the biomechanical and clinical feasibility and, secondly, to evaluate the clinical and functional outcomes of single-stage externalized locked plating for treatment of unstable, proximal (intra- and extra-articular) and distal (extra-articular), meta-diaphyseal tibial fractures. (2) Methods: Patients, who matched the inclusion criteria of sustaining a high-energy unstable meta-diaphyseal tibial fracture, were identified prospectively for single-stage externalized locked plating at a single trauma hospital in the period from April 2013 to December 2022. (3) Results: Eighteen patients were included in the study. Average follow-up was 21.4 ± 12.3 months, with 94% of the fractures healing without complications. The healing time was 21.1 ± 4.6 weeks, being significantly shorter for patients with proximal extra- versus intra-articular meta-diaphyseal tibial fractures, p = 0.04. Good and excellent functional outcomes in terms of HSS and AOFAS scores, and knee and ankle joints range of motion were observed among all patients, with no registered implant breakage, deep infection, and non-union. (4) Conclusions: Single-stage externalized locked plating of unstable meta-diaphyseal tibial fractures provides adequate stability of fixation with promising clinical results and represents an attractive alternative to the conventional methods of external fixation when inclusion criteria and rehabilitation protocol are strictly followed. Further experimental studies and randomized multicentric clinical trials with larger series of patients are necessary to pave the way of its use in clinical practice.

Percutaneous fixation of intraarticular joint-depression calcaneal fractures with different screw configurations - a biomechanical human cadaveric analysis.

PURPOSE: The aim of this study was to assess the biomechanical performance of different screw configurations for fixation of Sanders type II B joint-depression calcaneal fractures. METHODS: Fifteen human cadaveric lower limbs were amputated and Sanders II B fractures were simulated. The specimens were randomized to three groups for fixation with different screw configurations. The calcanei in Group 1 were treated with two parallel longitudinal screws, entering superiorly the Achilles tendon insertion, and two screws fixing the intraarticular posterior facet fracture line. In Group 2 two screws entered the tuberosity inferiorly to the Achilles tendon insertion and two transverse screws fixed the posterior facet. In Group 3 two screws were inserted along the bone axis, one transverse screw fixed the posterior facet and one oblique screw was inserted from the posteroplantar part of the tuberosity supporting the posterolateral part of the posterior facet. All specimens were biomechanically tested to failure under progressively increasing cyclic loading. RESULTS: Initial stiffness did not differ significantly between the groups, P = 0.152. Cycles to 2 mm plantar movement were significantly higher in both Group 1 (15,847 ± 5250) and Group 3 (13,323 ± 4363) compared with Group 2 (4875 ± 3480), P ≤ 0.048. No intraarticular displacement was observed in any group during testing. CONCLUSIONS: From a biomechanical perspective, posterior facet support by means of buttress or superiorly inserted longitudinal screws results in less plantar movement between the calcaneal tuberosity and the anterior fragments. Inferiorly inserted longitudinal screws are associated with bigger interfragmentary movements.