محمدحسین ابراهیم زاده

For over 50 years, bone cement has been used to strengthen artificial joints like hip, knee, shoulder, and elbow joints. The main purpose of bone cement is to fill the space between the prosthesis and the bone. This absorbs the forces on the joint by creating an elastic area. Besides ensuring the long-term stability of the artificial implant, it also improves the damaged bone. Polymeric bone cement consists of a polymer matrix known as polymethyl methacrylate (PMMA) and a liquid monomer called methyl methacrylate (MMA). When these two components are mixed, a free radical polymerization reaction occurs, leading to the cement's hardening at the place of use. The properties of bone cement, such as mechanical strength, biocompatibility, and handling characteristics, can be adjusted by combining the effective polymerization parameters. However, there are some challenges, such as heat generation during polymerization.
Ceramic bone cement is a composite material of ceramic particles dispersed in a polymer matrix, including calcium phosphate and calcium sulfate. The ceramic particles provide strength and bioactivity, while the polymer matrix enhances the transport properties of the cement. This combination results in a mechanically stable, bone-conductive, and biocompatible cement. Moreover, ceramic bone cement can be engineered to release therapeutic agents, such as antibiotics or growth factors, to prevent infection and foster bone regeneration. Ceramic bone cement is a promising alternative material for bone cement in joint replacement. However, more research and development are required to optimize the properties of bone cement and overcome the challenges associated with its use. With continued advancements in biomaterials, ceramic and polymer bone cement could revolutionize the field of orthopedic surgery and improve patient outcomes. Recent research has focused on developing new bone cement with improved properties like bioactivity, antibacterial activity, and drug delivery capabilities. These developments aim to enhance the performance of bone cement and remove the current limitations in orthopedic applications. In this review study, we will focus on the types of bone cement, their mechanical, biological, and structural properties, and how to optimize them.

The external fixators (pins) have many applications in orthopedic surgeries in the field of trauma. The success of clinical applications of external fixators has decreased due to their infection after orthopedic surgery. Meanwhile, the loosening of the pin embedded in the bone occurs due to the presence of bacteria and the formation of biofilm on the pin, and this infection will progress to the joint surface of the bone and the pin. Among the different techniques to improve the bone-pin interface in external fixation, coating the pins with antibacterial materials proved to be the most effective. Accordingly, the present study has focused on synthesis by sol gel method, structural, and antibacterial evaluations of Ag-FHA structure. The FESEM images and Mapping analysis confirmed the nano-scale size and homogeneous dispersion of particles in the Ag-FHA structure, respectively. In addition, the FTIR results indicated the hydroxyapatite formation in obtained structure. The XRD analysis has shown that the conversion of the amorphous phase to the crystalline phase occurred in all structures at a temperature of about 300 to 350 ° C , and the formation of the HA phase is increased and completed at 600 ° C. The antibacterial study was done by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determination. The obtained results showed that the Ag 0.2-FHA could significantly inhibit the growth of Staphylococcus aureus and Escherichia coli.

Fixators are the basic equipment for fractures that are divided into two categories, internal and external. The success of clinical applications of external fixators has decreased due to their infection after orthopedic surgery. Meanwhile, the loosening of the pin embedded in the bone occurs due to the presence of bacteria and the formation of biofilm on the pin, and this infection will progress to the joint surface of the bone and the pin. Natural elements with antibacterial activity attract much attention as a coating on implants surface in orthopedics surgery. This article reviewed common elements with antibacterial activity that can be loaded into the HA structure as a coating for improving their clinical efficiency. Substitution ions such as copper, silver, magnesium, strontium, zinc, silicon, and fluoride in an appetite network can stimulate bone formation at the fracture site. In this article, common antibacterial ions in the form of loading -HA have been investigated as coating orthopedic fixators. good strength and antibacterial activity presented for silver, and corrosion resistance and high porosity are advantages of copper. Also, magnesium with favorable biocompatibility and biodegradability, zinc with high strength, and silicon and fluorine with high flexibility, favorable mechanical properties, and corrosion resistance are introduced. Among the mentioned elements, silver and fluoride, due to having more favorable antibacterial activity and excellent bone regeneration, can be more suitable candidates for loading in the HA structure with the application of the coating on the orthopedic surface.

To improve the education of orthopaedic residents and enhance patient care in the Iran's healthcare system, it is necessary to gather information about the current status of scientific, practical, and research-based education for residents.

The research project initially focused on examining the executive curriculum in 14 centers affiliated with 6 different medical universities. Subsequently, an investigation was conducted into human resources, infrastructure, operating room facilities, educational and research outcomes, as well as the regular implementation of practical examinations to evaluate the performance of residents during their residency years. All the aforementioned aspects were covered using a comprehensive questionnaire, which was distributed via the "Formafzar.com" website as a link to the heads of departments in these centers by the Iranian Orthopaedic Association. The relationship between facilities and equipment and passing the future specialized orthopaedic board examination was also evaluated.

Among the examined centers, only 20% adhered to the criteria of Iran educational curriculum in all aspects of human resources, education, and research.

a regular evaluation of teaching methods used by international centers and the national curriculum is necessary for orthopaedic training centers in Iran. Additionally, regulatory systems should monitor the training process of orthopaedic residents to standardize services, equipment, and educational programs in the country.

Ankle arthrodesis is one of the major surgeries for the treatment of advanced osteoarthritis of the ankle joint. There are various techniques available for ankle arthrodesis and each technique has unique advantages and disadvantages. The aim of the present study was to evaluate the results of ankle arthrodesis with two this different approaches.

The medical records of the patients who were admitted for ankle arthrodesis and treated by a single surgeon from January 2015 to January 2020 were reviewed. The patients were recalled for re-evaluation after a mean follow-up of 19 months. Functional outcomes were assessed using validated AOFAS Ankle-Hind foot score, Manchester-Oxford Foot Questionnaire (MOXFQ) and visual analog scale (VAS) score for pain. The collected data were recorded in a pre-designed checklist and then analyzed using SPSS software.

A total of 32 patients, 18 men and 14 women with a mean age of 46.7 years were included in the study. 67.6% had history of ankle fractures. Anterior approach was used in 24 patients, 75%, and the rest of the patients had surgery with lateral approach (25%). The most common instrument for arthrodesis was concomitant use of plate and screws in 18 patients (56%). Union occurred in 28 patients (87.5%) within 11.1 weeks after the surgery. The AOFAS score increased significantly and MOXFQ and VAS scores decreased significantly following the surgery (p<0.001 for each). Advanced age and intramedullary nail were related to prolonged time to union (p<0.05). Surgical approaches (either anterior or lateral) had no association with AOFAS, MOXFQ, and VAS scores. Non-union was seen in 4 patients (12.5%) and deep infection in 3 patients (9.3%) after ankle arthrodesis.

The study results showed that, this surgery could improve patients’ pain and function with relatively low post-operative complications.

 Pulley is a synovial tissue that attaches the flexor tendons to the dorsal portions of the fibro-osseous tunnel near the tendon attachment. Pulley type A with ring structure is one of the most important pulleys in fingers. Two-stage reconstruction by silicon is the common treatment in damaged tendon which has long recovery time and the tendency of the repaired tendon to adhere to the fibrous-bone tunnel around it. Accordingly, the one-stage reconstruction by synthetic pulley is a promising approach to resolve the mentioned problems.

 In the present research, the polyurethane (PU) nanofiber scaffolds have been designed for synthetic pulley applications, and their mechanical and structural properties have been evaluated.

 The structural properties of nanofiber scaffolds show similar properties to protein and polysaccharide fibers in the extracellular matrix (ECM). The Fourier transform infrared spectroscopy (FTIR) results confirmed the functional groups of PU without any unwanted reactions. The amount of stress (3.19 ± 0.54) and Young's modulus (1.20 ± 0.39) in PU nanofiber scaffolds show similar mechanical properties to natural pulley.

 The obtained results showed that the PU nanofibers scaffolds can be proposed as a suitable candidate for fabrication of synthetic pulley in flexor tendon injuries.

Most third molars eventually need to be extracted, and this tooth has the most varied and unpredictable root position of all teeth. Therefore, considering the importance of accurate diagnosis of the roots of molar teeth before surgery to reduce its surgical complications, the aim of this study was to evaluate the ability of panoramic radiography to diagnose the situation of roots of third molars. the relationship of the roots to each other and the angle of the crown to the root in panoramic and clinical radiographs, respectively, using Romexis viewer and digimizer software were investigated.

In this cross-sectional-analytical study, 104 third molars of 93 patients referred for wisdom tooth extraction were examined clinically for the number of roots, the relationship of roots to each other and the angle of the crown to the root in panoramic radiography using Romexis Viewer  software and clinically after providing photograph and measuring the angle using digimizer software.

In evaluating the roots of third molars, the accuracy of panoramic radiographic interpretation regarding the number of roots was 63.27% and in the presence or absence of root, adhesion was 55.89%. In addition, Pearson correlation analysis showed that there was a significant relationship between the reported angle in radiographic interpretation and the actual angle (r = 0.318 and P value = 0.001).

Therefore, panoramic radiography is a valuable guide for third molar surgery. It is only necessary to consider its high error rate in terms of morphological details such as the number of roots and their relationship to each other.

Occurrence of infection is one of the complications of orthopedic surgery, which has bad consequences for the patient and the health care system. Loosing of bone tissue occurs due to the formation of a biological layer on the implant fixator, and it leads to the breaking of the infected implant and subsequently to local inflammation and bone destruction. In this review article, the effect of hydroxyapatite-loaded with antibiotics, due to its effective biological activity and appropriate chemical structure in orthopedic treatments is investigated. Vancomycin, gentamicin and tobramabicin are common antibiotics in orthopedic surgeries. The use of these mentioned antibiotics by injection cannot effectively reduce or treat the infection on the surface of the implant. In this regard, the use of antibiotic coatings on the implant surface can be a more effective method in controlling infection after orthopedic surgeries. Studies show that the implants coated with hydroxyapatite-loaded with antibiotics are a suitable choice for useful applications such as reducing recovery time, reducing pain and simultaneous growth of new bone on the implant. Researchers showed that the antibacterial activity and clinical applications of implants coated with hydroxyapatite along with antibiotics are very effective in orthopedic surgeries. All the examined antibiotics showed favorable results in the treatment of infection, and Vancomycin, due to its longer release time and the lowest level of toxicity compared to other antibiotics, can be used as a medicine. With more successful clinical results, it can be used in hydroxyapatite loading in order to cover the orthopedic schanzes

The aim of this study was to investigate the prevalence of Hepatitis B(HBV),Hepatitis C( HCV),and Human immunodeficiency virus(HIV)in a large trauma center in northeast of Iran.

In a descriptive cross sectional study, 27252 consecutive patients admitted in a trauma hospital in Mashhad, Iran during March 2012 to March 2017 who required surgery for their traumatic injuries were screened for the presence of Hepatitis B surface antigen (HBsAg), anti HCV Ab and anti HIV Ab.

In 926 patients at least one of the serologic tests was positive, showing an incidence of 3.3% seropositivity among study population. HBsAg was positive in 523 patients (1.9%), HCV Ab in 388 (1.4%) and HIV Ab in 15 patients (0.05%) respectively. 19 patients (0.06%) were simultaneously infected by more than one virus.

The results of this study demonstrate that seroprevalence of blood born-pathogens among trauma patients, especially HCV and HIV, are higher than general population and it emphasized that health care workers in trauma centers must adhere to standard precautions to prevent viral transmission.

This study aimed to evaluate the relationship between changes observed in an ultrasonography before and after the surgical release of carpal tunnel syndrome (CTS).

This prospective study was performed on 15 candidates of CTS surgery during 2017-2018 who underwent an ultrasonography before and three months after the surgery. The structural changes in the median nerve and their correlation with the carpal tunnel were analized.

According to ultrasonography results, the findings related to height, diameter and cross-sectional area  of the median nerve decreased in the pisiform region of carpal tunnel while they increased in the area of hamate hook (P=0.002 in pisiform and P=0.001 in hamate hook), which might be due to the elimination of nerve dysfunction in the pisiform and effective decrease of pressure on nerve in hamate hook.

In terms of evaluation of changes in the area of the median nerve, ultrasonography of the median nerve could be an effective and accurate technique to recognize the compression and follow up the nerve status in patients with CTS after surgery.

Femoral head fracture-dislocations are rare، while irreducible cases are even less frequent. Truly irreducible fractures such as the two cases in this report must be differentiated from incomplete reduction due to incarcerated bone or soft tissue interposition. Opinions vary on the surgical approach to be used once the hip is reduced and the fragment of the femoral head yet remains to be stabilized. The smith-peterson approach with the patient in the supine position provides a direct anterior view of the fracture site.

We reported two cases of Brumback-type 4، who were treated with this approach. Postoperatively we allowed weight-bearing after 3 months. After 14 and 10 months they had good results.

It seemed that Smith-Petherson approach was a good choice for this type of injuries.

Biodegradable polycaprolactone/starch composites can be used for bone tissue engineering applications. The effect of the ratio of components on composite properties is of tremendous importance.

Polycaprolactone/starch composite of 80/20 and 70/30 ratios were fabricated by dissolving them in chloroform followed by evaporation of the solvent.

The composites were characterized by fourier transform infrared spectroscopy. Their bioactivity was evaluated by studying the apatite formation ability after immersing the specimens in simulated body fluid. The results of compressive test on samples showed that the composite’s modulus and strength approximated that of human trabecular bone. Mass loss in distilled water and starch degradation rate in PBS was evaluated، which showed that the starch ratio was effective in composite degradation. MTT analysis and alkaline phosphatase levels showed that this composite had no toxicity and could increase G-299 cell line osteoblastic activities.

The increase in cellular osteoblastic activities and the ability for apatite formation on the composite surface، in addition to the polycaprolactone/starch samples'' mechanical properties shows their capability to be used as substitutes for bone. Because this composite degradation rate is controlled by changing the starch ratio، it has the potential for use in bone tissue engineering applications. Samples that have a 70/30 ratio are considered optimal due to their enhanced cellular response and better mechanical properties.

Tissue engineering is a science to generate biological substitutes for regeneration، preservation and better operation of damaged tissues. Main components of tissue engineering are scaffolds، cells and growth factors. Also، bioreactors seem to be one of the fundamental parts. Scaffold is a 3D structure as a framework to support cell growth and extra cellular matrix deposition. Cells penetrate to scaffolds and grow، differentiate، proliferate and migrate according to physical and chemical signals. If the environment is appropriate for cells، they deposit ECM and new tissue will be formed. Tissue engineering science is to fabricate scaffolds which are suitable for cellular homing، to create and retain appropriate environment for cell maintenance and to control all the parameters which is important to generate new tissues.