Measuring the osteochondral connection of the femoral head and neck in patients with impingement femoroacetabulare by determining the angle of two alpha in lateral and anteroposterior hip radiographic images

Background/Aim. Femoroacetabular impingement, a pathophysiological mechanism of small morphological changes of the hip leads to early arthritic changes. The aim of this study was to present a simple method for the quantification of femoral head and neck junction in patients with cam form of femoroacetabular impingement, in standardized anteroposterior and profile DUNN 90 radiograms of the hips. Methods. In standardized anteroposterior and profile DUNN 90 images of the hips we determined the angle of 2 alpha, defined by our own original method. We tested 141 hips in 81 patients without clinical signs of femoroacetabular impingement, and 153 hips in 76 patients with clinically clear signs of femoroacetabular impingement. Results. The value of the angle 2 alpha in anteroposterior hip radiograms was on average 113.7° for the patients with clinical symptoms of impingement, and 84.2° for the control group of patients (p ≤ 0.0001), and in DUNN 90 profile radiography of the hip, the value of 2 alpha angle in the patients group was 97.2°, and 74.6° in the control group (p ≤ 0.0001). The proposed method of determining the angle 2 alpha showed a high level sensitivity (97.8%) and specificity (98.7) and positive predictive value (98.6%). It was false positive in only 1.3%, and false negative in 2.12% of patients. Conclusion. Using standardized anteroposterior and profile radiographs of the hips, and without determination of femoral neck axis in patients with femoroacetabular impingement with the cam effect at the junction of the femoral head and neck, we proposed the method of measuring joint abnormalities of femoral head and neck junction, very capable to predict the disease development in an asymptomatic risk group of patients and high sensitive in the diagnosis of the disease in the group of patients

ANATOMIC AND PHYSIOLOGICAL FEATURES OF DISTAL LOWER LEG AND THEIR INFLUENCE ON THE PROCESS OF OSTEOGENESIS

Osteogenesis is the process of bone tissue forming, i.e. bone or callus regeneration. This process is influenced by many factors, and the degree of bone fragments’ stability and vascularization in the fracture area are the basic local factors which determine the nature of reparative process. Regenerative process of all bone structures increases with increasing of blood supply.The distal lower leg has its specific biomechanical features, and plays an important role in the transfer of body weight to foot. The distal part of tibia has a small diameter, which as a consequence has reduced diameter in medullar cave. Through this anatomic feature, the medullar network in the lower tibia part is also reduced.As for anatomic aspect, vascularization in the lower end of tibia is poor. It primarily depends on periosteal vascularization, because medullar vascularization is reduced. Fasciae, tendons and skin cover the lower part of the leg, and there is no muscle mass. These tissues have poor vascular network and that is why the extraosseous blood circulation in tibia is poor, and does not participate in the osteogenesis process. For these reasons, distal lower leg represents a predelection site for delayed osteogenesis and pseudoarthrosys development.Osteosynthesis causes secondary damage to bone and soft tissue circulation. The screw plate damages the periosteal circulation – in the lower part of tibia it is the main source of vascularization, and for this reason, this method of osteosynthesis should not be applied. The external fixator has a sparing role regarding vascularization, and that is the reason why this method is recommended for fracture stabilization at the level of distal lower leg

Distal tibial pilon fractures (AO/OTA type B, and C) treated with the external skeletal and minimal internal fixation method

Background/Aim. Distal tibial pilon fractures include extra-articular fractures of the tibial metaphysis and the more severe intra-articular tibial pilon fractures. There is no universal method for treating distal tibial pilon fractures. These fractures are treated by means of open reduction, internal fixation (ORIF) and external skeletal fixation. The high rate of soft-tissue complications associated with primary ORIF of pilon fractures led to the use of external skeletal fixation, with limited internal fixation as an alternative technique for definitive management. The aim of this study was to estimate efficacy of distal tibial pilon fratures treatment using the external skeletal and minimal internal fixation method. Methods. We presented a series of 31 operated patients with tibial pilon fractures. The patients were operated on using the method of external skeletal fixation with a minimal internal fixation. According to the AO/OTA classification, 17 patients had type B fracture and 14 patients type C fractures. The rigid external skeletal fixation was transformed into a dynamic external skeletal fixation 6 weeks post-surgery. Results. This retrospective study involved 31 patients with tibial pilon fractures, average age 41.81 (from 21 to 60) years. The average follow-up was 21.86 (from 12 to 48) months. The percentage of union was 90.32%, nonunion 3.22% and malunion 6.45%. The mean to fracture union was 14 (range 12-20) weeks. There were 4 (12.19%) infections around the pins of the external skeletal fixator and one (3.22%) deep infections. The ankle joint arthrosis as a late complication appeared in 4 (12.90%) patients. All arthroses appeared in patients who had type C fractures. The final functional results based on the AOFAS score were excellent in 51.61%, good in 32.25%, average in 12.90% and bad in 3.22% of the patients. Conclusion. External skeletal fixation and minimal internal fixation of distal tibial pilon fractures is a good method for treating all types of inta-articular pilon fractures. In fractures types B and C dynamic external skeletal fixation allows early mobility in the ankle joint. [Projekat Ministarstva nauke Republike Srbije, br. III41017

First experiences with the Fitmore® hip stem: Early results of the 16-month monitoring

Background/Aim. Fitmore® hip stem belongs to the group of short stem prostheses with the metaphysar stabilization, with its shape and form that protects the bone mass in the greater trochanter region and the distal part of the femur. The aim of this paper was to present the early postoperative results in patients with implanted Fitmore® hip stem and point out some of the advantages. Methods. A series of 10 patients with implanted Fitmore® hip stem, was included in this study. The average age of the patients was 54.5 (48–65) years. There were 5 women and 5 men. The total monitoring time was 16 months. To rate the condition of the hip joint we used The Western Ontario and Mc Master Universities Arthritis Index (WOMAC) score. We also monitored the degree of hip pain, hip flexion, heterotopic ossification and indentation in the stem of the prosthesis. Results. After 12 months of monitoring 9 (90%) of the patients had no pain in the thigh region, and only 1 (10%) experienced mild pain. The hip flexion rose from the average 89° to postoperative 114°. WOMAC score rose as well, from 49 to 94 average points. Indentation in the stem was registered 3 months after the operation in 2 (20%) of the patients – in one of the patients the indentation was 3 mm and in the other patient 5 mm. After the 16-month monitoring, the results were excellent. The monitoring period was short though it should be continued and the results should be presented after 5 and then after 10 years. Conclusion. Early results of the implantation Fitmore stem showed good bone ingrowth with excellent functional result

Surgical treatment of disloced fracture of the scapula column and glenoid: A 22-year follow-up

Introduction. Most scapular fractures are caused by highimpact blunt injuries, often as the result of motor vehicle accidents, fall from height, etc. In 80% to 90% of cases, scapula fractures are associated with multiple injuries (clavicle fracture, rib fractures, humeral fracture, pulmonary injury, brachial plexus injury). Case report. We presented scapular fracture in a 27-years-old male who had sustained a workrelated injury when a ground soil brick machine pressed him. Fracture line was identified on radiotherapy and computed tomography scan from the distal scapular angle enclosing scapular neck. The whole lateral part of the scapula was dislocated laterally from the scapular body. Scapular fracture was treated operatively. The posterior approach was used for reposition, while for fixation after reposition we used two Blunt clamps. We presented functional outcome 22 years after the injury and the surgical treatment. The patient can perform all physical activities, still works, and there is no need to remove the ostheosynthetic material as it causes no discomfort nor problems. The strength of the shoulder muscles is estimated as physician as the grade 5. Conclusion. Displaced intraarticular fractures of the scapula should be treated operatively, with open reduction and internal fixation

Surgical dislocation of the hip in patients with femoroacetabular impingement: Surgical techniques and our experience

Background/Aim. Arthrosis of the hip is the most common cause of a hip joint disorders. The aim of this study was to present our experience in the application of a safe surgical dislocation of the hip in patients with minor morphological changes in the hip joint, which, through the mechanism of femoroacetabular impingement, cause damage to the acetabular labrum and adjacent cartilage as an early sign of the hip arthrosis. Methods. We have operated 51 patients with different morphological bone changes in the hip area and resultant soft tissue damage of the acetabular labrum and its adjacent cartilage. Surgical technique that we applied in this group of patients, was adapted to our needs and capabilities and it was minimaly modified compared to the original procedure. Results. The surgical technique presented in this paper, proved to be a good method of treatment of bone and soft tissue pathomorphological changes of the hip in patients with femoroacetabular impingement. We had no cases with avascular necrosis of the femoral head, and two patients had nonunion of the greater trochanter, 9 patients developed paraarticular ossification, without subjective symptoms, while 3 patients suffered from postoperative pain in the groin during more energetic physical activities. Conclusion. Utilization of our partly modified surgical technique of controlled and safe dislocation of the hip can solve all the bone and soft tissue problems in patients with femoroacetibular impingement to stop already developed osteoarthritis of the hip or to prevent mild form of it

Early clinical results of surgical treatment of patients with femoroacetabular impingement

Introduction. Surgical treatment is the treatment of choice in patients with symptoms and radiological signs of femoroacetabular impingement. Objective. Our experience and early results of surgical treatment of patients with signs of femoroacetabular impingement and early hip osteoarthritis are reported. Methods. The results of treatment of 21 patients aged 23-54 years with different types of femoroacetabular impingement are presented. Safe open surgical dislocation of the hip was performed in all patients. Before and after surgery, the WOMAC score was performed, clinical and radiographic data of the operated hips were evaluated and t-tests were used for statistical analyzes of data. Results. The WOMAC score improved from 70.5 points ( range 56.3 to 89.8 points) to 90.3 points (range 70.3 to 100 points) at one year of follow-up (p<0.0001), anterior impingement test was negative in all operated cases, average hip internal rotation improved significantly, no complications were found, except trochanteric nonunion at the site of osteotomy, which was reaffixed. Conclusion. Postoperative results have shown that the surgical approach to treating patients with femoroacetabular impingement is the method of choice. Three operated patients, with advanced osteoarthritis of the hip, had to be converted to total hip replacement. [Projekat Ministarstva nauke Republike Srbije, br. III 41017 i br. III 41004

The microstructure and properties of as-cast Sn-Zn-Bi solder alloys

U radu su prikazani rezultati ispitivanja strukturnih i mehaničkih karakteristika bezolovnih lemnih legura u sistemu kalaj-cink-bizmut. Nakon dobijanja legura u indukcionoj peći sa zaštitnom atmosferom, trostrukim pretapanjem odmerene količine čistih metala, izvršena su ispitivanja strukture tako dobijenih uzoraka legura optičkom i skenirajućom electronskom mikroskopijom (SEM). Energetskom disperzivnom spektroskopijom (EDS) određen je hemijski sastav faza prisutnih u strukturi legura. Izvršena su merenja tvrdoće, i zatezne čvrstoće ispitivanih legura. Sva istraživanja su sprovedena sa ciljem boljeg upoznavanja osobina legura u sistemu Sn-Zn-Bi, koji se smatra odgovarajućom zamenom olovnih lemnih legura.Research on the lead-free solders has attracted wide attention, mostly as the result of the implementation of the Directive on the Restriction of the Use of Hazardous Substances in Electrical and Electronic Equipment. The Sn-Zn solder alloys have been considered to be one of the most attractive lead-free solders due to its ability to easily replace Sn-Pb eutectic alloy without increasing the soldering temperature. Furthermore, the mechanical properties are comparable or even superior to those of Sn-Pb solder. However, other problems still persist. The solution to overcoming these drawbacks is to add a small amount of alloying elements (Bi, Ag, Cr, Cu and Sb) to the Sn-Zn alloys. Microstructure, tensile strength, and hardness of the selected Sn-Zn-Bi ternary alloys have been investigated in this study. The SEM-EDS was used for the identification of co-existing phases in the samples. The specimens' microstructures are composed of three phases: Sn-rich solid solution as the matrix, Bi-phase and Zn-rich phase. The Bi precipitates are formed around the Sn-dendrit grains as well as around the Zn-rich phase. The amount of Bi segregation increases with the increase of Bi content. The Sn-Zn-Bi alloys exhibit the high tensile strength and hardness, but the values of these mechanical properties decrease with the increase of Bi content, as well as the reduction of Zn content. The results presented in this paper may offer further knowledge of the effects various parameters have on the properties of lead-free Sn-Zn-Bi solders

The microstructure and properties of as-cast Sn-Zn-Bi solder alloys

Research on the lead-free solders has attracted wide attention, mostly as the result of the implementation of the Directive on the Restriction of the Use of Hazardous Substances in Electrical and Electronic Equipment. The Sn-Zn solder alloys have been considered to be one of the most attractive lead-free solders due to its ability to easily replace Sn-Pb eutectic alloy without increasing the soldering temperature. Furthermore, the mechanical properties are comparable or even superior to those of Sn-Pb solder. However, other problems still persist. The solution to overcoming these drawbacks is to add a small amount of alloying elements (Bi, Ag, Cr, Cu, and Sb) to the Sn-Zn alloys. Microstructure, tensile strength, and hardness of the selected Sn-Zn-Bi ternary alloys have been investigated in this study. The SEM-EDS was used for the identification of co-existing phases in the samples. The specimens’ microstructures are composed of three phases: Sn-rich solid solution as the matrix, Bi-phase and Zn-rich phase. The Bi precipitates are formed around the Sn-dendrit grains as well as around the Zn-rich phase. The amount of Bi segregation increases with the increase of Bi content. The Sn-Zn-Bi alloys exhibit the high tensile strength and hardness, but the values of these mechanical properties decrease with the increase of Bi content, as well as the reduction of Zn content. The results presented in this paper may offer further knowledge of the effects various parameters have on the properties of lead-free Sn-Zn-Bi solders