Osteosynthesis System Research Articles

Influence of bone tissue regenerate on rigidity of fractures fixation

Based on experimental studies, an analytical method is proposed for an estimation of the influence of a regenerate of a bone fabric on rigidity of the system of osteosynthesis.
 A method for the experimental determination of displacements in the fracture region under the action of loads taking into account the regenerate has been developed and tested.
 A number of experiments were performed in compression, bending and torsion to determine the deformation characteristics of systems without regenerate and in its presence.
 The results of experiments related to the influence of bone regenerate formed during the fusion of fractures on the mechanical characteristics of the system "bone with a fracture - a means of fixation" are described. To assess the impact of bone regeneration, a method for studying the deformation of osteosynthesis systems using the method of modeling bone regeneration with a polymeric material with specified properties was developed and implemented.
 Using the stiffness condition, the expression for the calculation of permissible loads that do not lead to dangerous displacements of fracture points is obtained. The reduced deformations and permissible loads for the systems "bone with a fracture - a means of fixation" at different stages of bone tissue (ВT) regeneration under the action of compression, bending and torsion are calculated. It is established that the formed regenerate significantly increases the rigidity of the system "bone with a fracture - bone regenerate - a means of fixation", which increases the level of allowable loads on the extremities at different stages of treatment.
 Test and calculation data can be used to improve methods of treatment of damaged limbs in the intermediate and final stages of fracture fusion.

PEGASOS - A New Linking Mechanism for Modular Osteosynthesis Plates in Minimally Invasive Acetabular Surgery

Abstract Background: Recently presented minimally invasive endoscopic surgical techniques demonstrated the feasibility of implanting standard osteosynthesis plates for pelvic fractures. The reconstruction and internal fixation of complex acetabular fractures is still challenging. The goal of this study is to introduce a divisible implant, with a positive-locking in situ linking mechanism for plate osteosynthesis, making it possible to stabilize large and complex acetabular fractures with involvement of the quadrilateral surface. Method: Standard implants were used to recreate a base design. Using computer aided design (CAD), a three-dimensional standard implant was divided into two parts, so they could be re-allocated in situ. A critical objective was to reduce the cross-section of each part (clearance gauge). To connect the separated parts in situ, a new linking mechanism (cone in cone) was created. The new construct also features self-stabilization, self-centering, reinforced positional movement and preloading effects. Results: A linking system for plate osteosynthesis was developed entitled PEGASOS ("Percutaneous Endoscopic Guided Acetabulum-Stabilizing Osteosynthesis System"). Endoscopic implantation and in-situ-linking could be performed in a human cadaver. Therefore, we could demonstrate, that buttressing the quadrilateral surface of the acetabulum could be performed minimally invasive using a divisible suprapectineal buttress plate. Conclusion: We created a linking mechanism to couple two plates in situ. This mechanism enables an extremely strong, positive-locking connection, whereas its geometric shape allows for different relative movements during the locking procedure, with a single screw.

FEATURES OF MECHANICAL TESTS OF OSTEOSYNTHESIS SYSTEMS

Various methods of measuring the characteristics of stiffness and strength of systems "bone with a fracture - a means of fixation" are considered. Methods for measuring deformations of osteosynthesis systems are systematized, which take into account the nature of the action of external loads and allow to compare different systems of osteosynthesis. The rational arrangement of drugs at tests taking into account features of a structure of bones and the real loadings arising
 at functioning of musculoskeletal system is recommended. It is proposed to use the stiffness characteristics of the systems "bone - means of fixation" under the action of axial compression, transverse bending and torsion, including in cyclic modes; considered systems of osteosynthesis with the most common methods of fixing fractures to select the optimal in terms of quality methods of fixing fragments in fractures. It is established that the stability indicators of osteosynthesis
 systems, measured in the process of cyclic tests, are more sensitive to the type of fixing means and can be used to rank these systems according to the degree of mechanical reliability. The results of research obtained using these methods are implemented in surgical practice in the selection of optimal designs of fixation devices and the rational location of fixing elements.

In vivo biocompatibility and degradability of a Zn–Mg–Fe alloy osteosynthesis system

Zinc is generally considered to be one of the most promising materials to be used in biodegradable implants, and many zinc alloys have been optimized to improve implant biocompatibility, degradation, and mechanical properties. However, long-term degradation leads to the prolonged presence of degradation products, which risks foreign body reactions. Herein, we investigated the in vivo biocompatibility and degradation of a biodegradable Zn–Mg–Fe alloy osteosynthesis system in the frontal bone, mandible, and femur in beagles for 1 year. Results of the routine blood, biochemical, trace element, and histological analyses of multiple organs, peripheral blood CD4/CD8a levels, and serum interleukin 2 and 4 levels showed good biocompatibility of the Zn–Mg–Fe alloy. Zinc content analysis revealed zinc accumulation in adjacent bone tissue, but not in the liver, kidney, and spleen, which was related to the degradation of the Zn–Mg–Fe alloy. The alloy demonstrated a uniform slowing degradation rate in vivo. No degradation differences in the frontal bone, mandible, and femur were observed. The degradation products included zinc oxide [ZnO], zinc hydroxide [Zn(OH)2], hydrozincite [Zn5(OH)6(CO3)2], and hopeite [Zn3(PO4)2·4H2O]. The good biocompatibility and degradation properties of the Zn–Mg–Fe alloy render it a very attractive osteosynthesis system for clinical applications.

Application of Anatomically Designed 2-Dimensional V Plate in Management of Mandible Fracture: A Pilot Study.

Mandible is the only mobile facial jaw bone and it aides in various functions such as phonation and mastication. Therefore, management of mandible fracture becomes inevitable due to its functional and anatomical importance. Fracture fixation methods and techniques have steadily evolved with various osteosynthesis systems. In this article, we discuss the management of mandible fracture using a newly designed two-dimensional (2D) hybrid V-shaped plate. In this paper, we have evaluated the efficacy of the newly developed 2D V-shaped locking plate in the management of mandibular fractures. We have assessed 12 cases of different mandibular fractures ranging from symphysis, parasymphysis, angle and subcondylar region. Treatment outcome was assessed both clinically and radiologically at regular intervals with various intraoperative and postoperative parameters. Results of this study suggest that fixation of mandible fracture with the 2D hybrid V-shaped plate facilitates anatomic reduction and functional stability and carries a low morbidity and infection rate. The 2D anatomic hybrid V-shaped plate can be a suitable alternative to conventional miniplate and 3D plates as it offers satisfactory anatomic reduction and functional stability. Positioning the plate in relation to the mental nerve and plate adaptation along the angle region are much easier.

Complications of Poly-l-Lactic Acid and Polyglycolic Acid (PLLA/PGA) Osteosynthesis Systems for Maxillofacial Surgery: A Retrospective Clinical Investigation.

Two second-generation PLLA/PGA bioresorbable osteosynthetic plate systems for oral and maxillofacial surgery are available in Japan. The two systems have different PLLA-PGA component ratios (RapidSorb®, 85:15; Lactosorb®, 82:18) and plate and screw shapes. We conducted a retrospective study to compare our clinical evaluation and examine the incidence of postoperative complications between the two plate systems. A retrospective survey was conducted in 148 patients (midfacial fracture/trauma (68.2%) and dentofacial deformity patients (31.8%); males (54.7%); median age, 37.5 years) treated using maxillofacial osteosynthetic plate systems. The complications included plate exposure (7.4%), infection, (2.7%), and plate breakage (0.7%). Multivariate logistic regression analysis showed a significant correlation between sex (female), plate system (Lactosorb®), number of plates, and pyriform aperture and periorbital sites of plate placement (p < 0.05). Additionally, the propensity score-adjusted model showed a significant correlation between Lactosorb® and postoperative complications (odds ratio 1.007 (95% confidence interval, 1.001–1.055), p < 0.01). However, the two plate systems showed a low incidence rate of complications, and the plate integration and survivability were similar using 2.0-mm or 1.5-mm resorbable plate regardless of the plate system. Our findings suggest that female sex and a greater number of plates are risk factors for postoperative complications, whereas pyriform aperture and periorbital plate placements reduce the risk.

Comparative Study between Intra-medullary Nailing and Minimally Invasive Plate Osteosynthesis (MIPO) in Closed Distal Tibia Fracture in a District Hospital in Bangladesh

Introduction: Tibia fractures are the most common long bone fractures encountered by the orthopedic surgeons and distal tibia fractures have the second highest incidence of all tibia fractures after the middle third of tibia the distal tibial fractures are unique and are considered as most challenging fractures to treat due to its proximity to the ankle joint and its superficial nature. The objective of this study is to compare two osteosynthesis systems developed for surgical treatment of distal tibia fractures: the intramedullary nailing and the MIPO technique.&#x0D; Methods: The study was conducted between Jan 2018 to Dec 2019. 30 patients with extraarticular distal tibia fracture treated with intramedullary nailing and MIPO technique were reviewed retrospectively and clinical outcome was evaluated according to American Orthopaedic Foot and Ankle Score.&#x0D; Results: 15 patients were treated with intramedullary nail and 15 with MIPO technique. Fibular fixation was done in cases where fibular fracture was at or below the level of tibial fractures. We found no difference in terms of time for fracture union, mal-union, non-union, duration of surgery and amount of blood loss. But there was significant difference in terms of infection and duration of hospital stay. Also weight bearing was possible much earlier in intramedullary group as compared to the MIPO group.&#x0D; Conclusion: Thus we conclude that intramedullary nailing is better choice of implant in patients with extra- articular distal tibia fractures and helps in early weight bearing and ambulation of patient with fewer complications.&#x0D; J Shaheed Suhrawardy Med Coll, December 2020, Vol.12(1); 33-37

Photoelastic analysis of conventional and locking system for treatment of mandibular angle fractures with a single plate

BackgroundThis photoelastic analysis evaluated stress distribution in different osteosynthesis systems, conventional and locking, used for treatment of mandibular angle fractures with a single plate. Material and MethodsAngle fractures were simulated in mandibles made of photoelastic resin. Following Champy’s method, plate osteosynthesis was performed. The samples were divided into five groups: Group 1, non-fractured mandible; Group 2, two screws were installed in each segment using a conventional system; Group 3, two screws were installed in each segment using a locking system; Group 4, three screws were installed in the proximal segment and four screws in the distal segment using a conventional plate; Group 5, three screws were installed in the proximal segment and four screws in the distal segment using a locking plate. In an universal testing machine coupled to a polariscope, a load was applied to the first molar 10 times. The 50 images were randomly numbered and analyzed qualitatively and quantitatively by two raters. ResultsThe locking system promoted better stress distribution along the osteosynthesis. The locking system reduced stress magnitude in the distal segment, with a significant between-group difference (P≤ 0.001). ConclusionsThe locking plate/screw system can distribute stress more evenly throughout the osteosynthesis, especially when long seven-hole plates are used. Key words:Internal fracture fixation, osteosynthesis, mandibular fracture, bone plates.

Comparison of the mechanical properties of biodegradable and titanium osteosynthesis systems used in oral and maxillofacial surgery

To guide the selection of osteosynthesis systems, this study compared the mechanical properties of biodegradable and titanium osteosynthesis systems. SonicPins Rx and xG were subjected to pull-out tests. Additionally, 15 biodegradable (Inion CPS 2.0 and 2.5 mm; LactoSorb 2.0 mm; Macropore 2.0 mm; Polymax 2.0 mm; BioSorb FX 2.0 mm; ResorbX 2.1 mm; Osteotrans-MX 2.0 mm with plate thicknesses 1.0 and 1.4 mm; SonicWeld Rxplate/Rxpins, xGplate/Rxpins and xGplate/xGpins 2.1 mm without and with tapping the burr hole) and six titanium (CrossDrive (2006), CrossDrive (2018), MaxDrive; all 1.5 and 2.0 mm) straight, four-hole osteosynthesis systems were evaluated. All systems were subjected to tensile, bending and torsion tests. Pull-out loads of the SonicPins were comparable (P = 0.423). Titanium systems’ tensile loads were higher than biodegradable systems (P < 0.001). CrossDrive (2018) and MaxDrive systems’ tensile and torsional stiffness were lower, accompanied with higher ductility, than corresponding CrossDrive (2006) systems (P < 0.001). Bending stiffness of 1.5 mm titanium systems was comparable to, and of the 2.0 mm systems higher than, all biodegradable systems (P < 0.001). Regarding biodegradable systems, Inion CPS 2.5 mm had highest tensile load and torsional stiffness, SonicWeld 2.1 mm highest tensile stiffness, and BioSorbFX 2.0 mm highest bending stiffness (P < 0.001). On the basis of the results of this study, the CrossDrive (2018) and MaxDrive 1.5 mm titanium systems are recommended for midface fractures (e.g., zygomatic or maxillary fractures) and osteotomies (e.g., Le Fort I osteotomy), and the CrossDrive (2018) and MaxDrive 2.0 mm titanium systems for mandibular fractures and osteotomies when a titanium osteosynthesis system is used. When there is an indication for a biodegradable osteosynthesis system, the SonicWeld 2.1 mm or BioSorbFX 2.0 mm are recommended for midface fractures and osteotomies, and the Inion CPS 2.5 mm biodegradable system for mandibular osteotomies and non-load bearing mandibular fractures, especially when high torsional forces are expected (e.g., mandibular symphysis fractures).

Comparison of the Biomechanical Stiffness of Titanium and Sonic Weld RX Osteofixation Systems for Monoblock Zygomaticomaxillary Complex Fractures.

Resorbable osteosynthesis systems are widely used for the fixation of zygomaticomaxillary complex (ZMC) fractures instead of titanium systems, because they do not have postoperative hardware-related complications. However, the strength of conventional resorbable systems is inferior to that of titanium systems. Recently, ultrasound-aided resorbable osteosynthesis systems, which have higher fixation than conventional resorbable osteosynthesis systems, have become available.The purpose of this study was to compare the mechanical stiffness of the ultrasound-aided resorbable and titanium osteosynthesis systems in a cadaveric monoblock ZMC fracture model. Three human cadaveric monoblock ZMC fracture models (6 zygomas) were created. The fixation materials included the titanium (Level One Fixation; KLS Martin, Germany) and ultrasound-aided resorbable osteofixation systems (SonicWeld RX; KLS Martin). The fixation methods included the 3-point (zygomaticofrontal [ZF], zygomaticomaxillary buttress, and inferior orbital rim [Group I]) and the 2-point (ZF + inferior orbital rim [Group IIa] and ZF + zygomaticomaxillary buttress [Group IIb]) fixations. Each fixation model was mechanically tested with a load of up to 100 N, based on the previously reported postoperative masseter muscle strength, and the stiffness was calculated. Titanium was found to be stiffer than SonicWeld RX, though not significantly different. The fixation points in decreasing order of stiffness were Group I, Group IIa, and Group IIb, though the differences were not significant. In conclusion, the 2-point fixation, including the ZF fixation with SonicWeld RX, can be used as an alternative to the 3-point titanium fixation, which is considered to be stronger and stiffer.

Spatial deformations of osteosynthesis systems. Message 2. Experimental results

Test procedure and a device for the spatial loading of full-scale bone specimens with fractures and fixation means and simultaneous measurement of mutual displacements arising in the fracture region due to the load are presented. The device allows us to apply longitudinal, transverse bending and rotational one-time and long-term cyclic loads to the specimen, simulating the action of loads when walking. The measurement of displacements was carried out by digitally photographing the fracture areas followed by computer image processing.The test results of the “tibia with simulated fracture - fixation plate” systems under spatial loading by three external forces are presented, which cause compression, bending and torsion. As a result of the tests, the values of mutual displacements and the angles of mutual rotation of parts of the fracture were measured.Comparison of test and calculation results using the relationships described in Message 1 shows the suitability of the method, which allows us to quickly and reliably assess the level of displacements in bone fractures under the spatial loading.

MANAGEMENT AND OUTCOME ANALYSIS OF PROXIMAL HUMERUS FRACTURES BY PHILOS - A PROSPECTIVE STUDY

Introduction: Proximal humerus fracture is considered as one of the commonest fractures in clinical practice. Most of these fractures occur as a result of osteoporosis. Proximal humerus fractures are often nondisplaced or minimally displaced fractures with two parts, which can be managed conservatively. Surgical interventions include closed reduction and percutaneous pinning (CRPP). It also involves trans-osseous suture fixation, Open Reduction Internal Fixation (ORIF) with either conventional or Proximal Humerus Interlocking Osteosynthesis System (PHILOS) or hemiarthroplasty. Good clinical outcomes have been achieved by the PHILOS as they stabilize the proximal humeral fractures with steady fixation in osteoporotic bone and assisted aged patients in early functional exercises which resulted in early recovery. &#x0D; Aim: To analyse the functional results and complications associated with management of proximal humerus fractures treated with PHILOS.&#x0D; Materials and Methods: This is a prospective study conducted at Department of Orthopaedics, Prathima Institute Of Medical Sciences, Nagunur, Karimnagar, from July 2017 to January 2019. 58 patients were taken into study with two-part, three-part, four-part fracture of the proximal humerus in adults &gt;18 years of age. In all patients PHILOS plating was done and surgical events and surgical difficulties faced, post-surgery local or systemic complications, time needed for fracture union and time taken to return to pre-fracture activity were documented. They were followed up till there were signs of union on radiographs or for at least a period of 1 year.&#x0D; Results: The results were assessed with Constant Murley Score at 6 months post-surgery and Visual Analogue Scale at 6 weekly intervals. The mean Constant score for two-part fractures was 88.1, for Three-part 82.5, for Four-part 72.7. The patients with two-part and three-part fractures had a significantly better VAS than patients with four-part fractures till 18 months of surgery. After 18 months the VAS was similar for all 3 groups. 6.9% developed shoulder stiffness, 2 patients from four-part fracture group developed Varus angulation.&#x0D; Conclusion: we conclude that the PHILOS is safe, effective and provides stable fixation for proximal humerus fractures and in patients with indigent bone quality. &#x0D; Keywords: PHILOS, Proximal Humerus Fracture

Mechanical properties of the bone-implant systems in conditions of the stable functional osteosynthesis

Fractures of the diaphysis of leg bones make up 45% of all long bone fractures, they are one the most common injuries to the bones of the limb segments, the treatment of which is accompanied by a large number of complications, therefore the problem of improving the treatment of patients with this injury is still relevant for present traumatology and orthopedics. The use of compression distraction systems, intramedullary and extramedullary osteosynthesis systems allows a stable functional osteosynthesis and eliminates the need for additional gypsum immobilization of a segment or limb in the postoperative period. Biomechanical relations in the bone-implant system in conditions of a stable functional osteosynthesis constitute an important factor allowing to objectify the mode of motion rehabilitation in the early postoperative period. This work studies the results of the comparative bench tests of groups of cadaver tibia in experimental injuries of type 42 A 1.1. (according to the Association for Study of Internal Fixation (AO/ASIF)) synthesized with different types of implants, such as Fixion expanding system of fixation, external fixation devices, Limited Contact Dynamic Compression Plate (LC-DCP) and blocked intramedullary osteosynthesis system (BIOS)). Each system was axially compressed using INSTRON 1185. Resistance to axial compression has been analyzed. It is noted that all these types of fixations increase the strength of the systems in the range of 22–81% compared to the intact specimens. Intraosseous fixation systems demonstrated the highest strength, which has the most optimal biomechanical relations in the bone-implant system, allowing to objectify the regime of motion rehabilitation.

Distribution of bone thickness in the human mandibular ramus \u2013 a CBCT-based study

BackgroundThe bone thickness of the human mandibular ramus is an important parameter in mandibular surgeries. The aim of this study was to systematically measure the bicortical bone thickness, the ramus dimensions and the position of the lingula. The measurements were tested on significant correlations to the patients’ parameters.MethodsBased on CBCT scans 150 rami were reconstructed as 3D polygon surfaces. An anatomical grid was adapted to the ramus surface to mark the bone thickness measurement points and to achieve comparability between the measurements on different mandibles. The bone thickness, ramus height, ramus width and the gonion angle were measured. A cluster analysis was performed with these parameters to identify clinically relevant groups with anatomical similarities.ResultsThe median distribution of the bone thickness was calculated and visualized in a pseudo-colour map. The mean ramus height was 44.78 mm, the mean width was 31.31 mm and the mean gonion angle was 124.8°. The average distance from the lingula to the dorsal tangent was 53% of the total width and its distance to the caudal tangent was 65% of the total height. Significant correlations between the bone thickness and the ramus proportions could be identified. Age and sex had no significant influence on the mean bone thickness. The measured rami could be divided into two groups by cluster analysis.ConclusionThe dimensions of the human mandibular ramus can be determined from 3D reconstructed surface models from CBCT scans. Measurements could be made comparable by applying an anatomically oriented grid. A cluster analysis allowed the differentiation of two groups with different bone thickness distributions and geometries, which can be used for the optimization of osteosynthesis systems and their precision of adaptation to different ramus morphologies.

Supraintercondylar fracture of the proximal phalanx of the hallux

Toe phalanx fractures are prevalent worldwide. The proximal phalanx of the hallux requires different treatment from the other four lateral phalanges. Poor positioning of rotation and angulation is not acceptable for this bone, since it can result in significant functional deficit. Indications for surgical treatment are: joint fractures with deviations greater than 2 mm, metadiaphyseal fractures with rotational and/or angular deviation, open fractures and unstable fractures. The classic medial approach in surgical treatment involves some high-risk neurovascular structures and does not allow the correct positioning of osteosynthesis systems in some cases. The aim of this study is to present an option for the surgical treatment of deviated and unstable supraintercondylar fractures of the proximal phalanx of the hallux by the dorsolateral approach, with a traction screw through the plate and a lateral neutralization plate. Level of Evidence V; Therapeutic Study; Expert Opinion.

Spatial Deformation of Osteosynthesis Systems. Message 1. Criteria of Functional Reliability.

Based on experimental studies, an analytical method is proposed for assessing the functional reliability of osteosynthesis systems. As criteria for the rigidity of osteosynthesis systems, displacements and mutual rotations of parts of bone fractures with fixation tools were used. The characteristics of the “bone with a fracture - fixation system”, necessary for calculations, determined experimentally from individual loads by compression, bending, and torsion of bone samples with simulated fractures and fixation tools.The characteristics of the plates for fixation of tibial fractures are determined, the level of allowable loads is calculated according to the combined action of compression, bending and torsion, and the areas of valid loads are determined.The proposed criteria for functional reliability make it possible, using simple tests and analytical calculations, to determine permissible load levels that do not lead to the occurrence of dangerous movements in the fracture area.

Chest Wall Reconstruction Following Tumor

Plastic surgeons are typically called upon to reconstruct the chest wall in four situations: oncologic resection, infections, trauma and osteoradionecrosis. In this chapter we will discuss post-oncologic reconstruction. Chest wall reconstruction following tumor resection is typically performed at the same setting as the ablative surgery; this results in quicker patient recovery and overall better outcomes. The reconstruction should be planned with the ablative surgeon so that an assessment can be made of the extent of resection and available donor sites for reconstruction. The major components of reconstruction are 1) skeletal support and 2) soft tissue coverage. Skeletal support is indicated if the defect is &gt;5 cm, 4 or more ribs are removed or more than 2/3rd of the sternum is resected. Prosthetic mesh is most commonly used. Soft tissue reconstruction is performed with regional pedicled flaps in the vast majority of cases. Free flaps are used when regional flaps are not sufficient (large defects) or not available. This review contains 11 figures, 3 tables, and 49 references. Keywords: chest wall, tumor, skeletal reconstruction, soft tissue reconstruction, mesh, acellular dermal matrix, titanium osteosynthesis systems, resorbable plates, pedicled flaps, free flaps

Occlusal Instability Results in Increased Complication Rates After Treatment of Mandibular Fractures

It is important to understand the factors that can increase the incidence of complications after mandibular fracture (MF) treatment. The objective of the present study was to investigate whether occlusal stability influences the occurrence of postoperative complications in MFs treated with internal rigid fixation. We performed a prospective cohort study of patients treated for MF by osteosynthesis with plate and screw fixation. The primary predictor variable was the occlusal stability (yes vs no). Occlusion was scored as stable (group 1) if the patients had all their teeth and no free ends in either dental arch. Occlusion was coded as unstable (group 2) if the patients were partially edentulous with free ends in either dental arch or had edentulism involving more than 6 dental elements. The primary outcome variable was postoperative complication (yes vs no). The secondary outcome variables were the osteosynthesis system used (2.0 or 2.4mm), local factors, age, and gender. Statistical analysis was performed using the χ2 statistical test at 5% significance. Of 115 patients with 121MFs, 73 (63.48%) had stable occlusion (group 1) and 42 (36.52%) had unstable occlusion (group 2). The mean age was 34.11years, and 71.3% were men. The postoperative complication rate was 8.70% (10 patients). Of the 10 patients with complications, 3 (2.6%) were in group 1 and 7 (6.1%) were in group 2 (P=.021 and P<.05, respectively). The 2.0-mm system was used in 107 cases (93%). All the complications were associated with use of the 2.0-mm osteosynthesis plates, occurring in 3 of 69 patients in group 1 (4.34%) and 7 of 38 patients in group 2 (18.42%; P=.032 and P<.05, respectively). The greatest number of complications was associated with unilateral MF (9 of 109). The occurrence of postoperative complications in angle and symphysis/parasymphysis fracture sites was equal. The results of the present study suggest that unstable occlusion could increase the rate of postoperative complications in MFs treated with plates and screws. Future studies are required with occlusal stability included as a variable.

Surgical correction of recurrent pectus excavatum of an adult patient, case report, and review of literature.

The aim of this paper is to review the literature on recurrent pectus excavatum (PE) and present our surgical approach to a complex case of recurrent PE in an adult patient at a Mexican Hospital. We present the case of an adult patient with severe and symptomatic PE, with history of a failed Nuss procedure 1 year previous our intervention, which consisted of a combination of both classic techniques, by performing an osteochondrectomy of affected cartilages and placing a titanium bar substernal and stabilizing coastal arches with secondary osteosynthesis system (Stratos ™ system, medXpert, Germany). Adequate correction of thoracic silhouette and both cardiac and respiratory disorders in the 1-year follow-up was achieved as indicated by the improvement of the patient's Haller index. Successful surgical correction of pectus excavatum is achieved when the thoracic silhouette is restored, thus improving cardiopulmonary symptoms. As there are many different techniques available, the more minimally invasive ones are reserved for mild cases, but the treatment of complex cases as in our patient requires a combination of multiple techniques and reconstruction materials in order to achieve adequate correction of the thoracic deformity and reduce recurrence rate.

Biodegradable versus titanium osteosynthesis in maxillofacial traumatology: a systematic review with meta-analysis and trial sequential analysis

Titanium osteosynthesis is currently the fixation system of choice in maxillofacial traumatology. Biodegradable osteosynthesis systems have the ability to degrade in the human body. The aim of this study was to conduct a systematic review, with meta- and trial sequential analyses, to assess the efficacy and morbidity of biodegradable versus titanium osteosynthesis after maxillofacial trauma. MEDLINE, Embase, and CENTRAL were searched for randomized controlled trials and prospective and retrospective controlled studies. Five time periods were studied: perioperative, short-term (0–4 weeks), intermediate (6–12 weeks), long-term (>12 weeks), and overall follow-up. After screening 3542 records, 24 were included. All had a high risk of performance and detection bias due to the nature of the interventions. Meta-analysis showed no differences in efficacy or morbidity between biodegradable and titanium osteosynthesis. The risk of perioperative screw breakage was significantly higher (risk ratio 17.13, 95% confidence interval 2.19–34.18) and the symptomatic plate removal rate lower in the biodegradable group (risk ratio 0.11, 95% confidence interval 0.02–0.57), which was confirmed by the trial sequential analysis. The quality of evidence ranged from very low to moderate. Based on the narrative review and meta-analyses, current evidence shows that biodegradable osteosynthesis is a viable alternative to titanium osteosynthesis when applied in the treatment of maxillofacial trauma, with similar efficacy but significantly lower symptomatic plate removal rates. Perioperative screw breakage occurred significantly more often in the biodegradable group compared to the titanium group.