Introduction: Avascular necrosis or osteonecrosis of the femoral head is defined as a pathological process that results in a critical reduction in the blood supply to the hip head with increased intraosseous pressure. Avascular necrosis is a multifactorial disease. The treatment used so far consists of transosseous decompression of the femoral head and is the most commonly used method in the early stages of osteonecrosis. Aim: The aim of this study was to evaluate the results after application of bone marrow stem cells obtained from the pelvic ridge, which was applied to the necrotic zone after previous decompression. Material and methods. The study is of prospective character and included 30 patients with first, second, and third degrees of AVN according to the Ficat classification, determined with X-ray. The range of motion in the hip was examined preoperatively by using a goniometer, a radiological evaluation of the degree of AVN was performed, according to the Ficat classification, and the VAS scale and the Harris Hip Score were examined preoperatively and postoperatively. Results: The average value for the Harris Hip Score (HHS) preoperatively was: for Ficat I -66.32±5.1, for Ficat II - 49.19±3.4 and for Ficat III - 33.71±2.1. At the 3-month postoperative follow-up, the average HHS values were: 87.92±4.3 for Ficat I, 78.64±6.6 for Ficat II and 76.48±2.6 for Ficat III. The same values for HHS were obtained in the control examinations at the 6th and 12th month postoperatively, indicating the fact that good bone regeneration was achieved and the progression of the condition was prevented. A decrease in the HHS value was observed at the control examination at 1 year after the surgical treatment, in 3 patients according to the Ficat classification of grade III, in whom a total hip replacement surgery was performed. Conclusion: The use of stem cells in the treatment of avascular necrosis of the femoral head has achieved good functional results and reduced pain in operated patients. Radiographically, good bone regeneration was achieved and the progression of necrosis to a higher degree was prevented.

Total hip arthroplasty (THA) is now the gold standard for the surgical treatment of coxarthrosis. The appearance of bone loss after implantation of the hip endoprosthesis over time reduces the primary stability of the implant and leads to progressive looseningof the implant, or periprosthetic fracture, which are considered to be the most common causes of hip revision. The aim of this study is to evaluate the value of alendronate application in reducing periprosthetic osteolysis reduction after implantation of total cementless hip endoprosthesis. The study analyzed 50 patients operated on with implantation of a cementless total hip arthroplasty (THA). The first group of 25 patients recieved oral alendronate, calcium and vitamin D3 postoperatively. The second group of 25 patients were examined and followed postoperatively without any therapy. Patients were examined by RTG and DXA methods at 6, 12 and 18 months. The study showed a difference in the values of bone mineral density (BMD) and bone mineral content (BMC) in the interval of 6,12 and 18 months, using the DXA method. Alendronate therapy after total hip implantation reduces periprosthetic bone loss, maintains  bone mineralization and strengthens the implant

Introduction: Revision knee arthroplasty is not a routine procedure and almost always it is a technically demanding operation. The paradigm in revision total knee arthroplasty is to achieve correct alignment of the components, maintenance of the joint space and ligament balance by providing a stable bone -implant fusion. Metaphyseal bone loss is a crucial problem in revision total knee arthroplasty. The bone loss is due to primary arthroplasty technical errors and design, or problematic removal of the implants.Aim: The aim of this article is to present our experience on total knee revision surgery using tantalum metal cones as a structural bone graft substitute in total arthroplasty failure with gross metaphyseal bone loss categorized by the AORI classification, performed by a specific surgical technique and evaluated by the Knee Society Score (KSS). Material and methods:From 2013 to 2016 at the University Clinic for Orthopedic Surgery in Skopje 21 patient has been treated with revision total knee arthroplasty. Twelve patients had type 1/type 2 bone defects according to AORI, and nine had type 3 bone defect. We used trabecular metal bone graft in type 3 bone defects. A special emphasis is placed on preoperative planning according to the classification system for ligament and soft tissue damage as well as the AORI classification in order to determine the quantity, location and extent of the bone loss. In our series in patients with type 3 deformities, trabecular metal augments were used. This material resembles the human trabecular bone by its cellular structure and elastic characteristics.Results: Preoperatively, all the patients had Knee Society Score below 60, most of them were housebound, experiencing great pain and disability. After six months 95% were rated excellent, and on one year follow up, 89% were rated good or excellent (KSS score above 82, mean score 81.5), 1 patient was marked as poor with a complication -dislocation of the prosthesis. In the follow up period there was no infection. Conclusion:Our results of revision knee arthroplasty by using the trabecular metal augments with at least a year of follow up are excellent according to the KSS compared to the other studies. The disadvantages of the study are mentioned and the need for further investigation is stressed.

Background: Radiographic examination of extremities in surgical lengthening and/or correction of deformities is of crucial importance for the assessment of new bone formation. The purpose of this study is to confirm the diagnostic value of radiography in precise detection of bone parameters in various lengthening or correction stages in patients treated by limb-lengthening and deformity correction.Patients and Methods: 50 patients were treated by the Ilizarov method of limb lengthening or deformity correction at the University Orthopaedic Surgery Clinic in Skopje, and analysed over the period from 2006 to 2012. The patients were divided into two groups. The first group consisted of 27 patients with limb-lengthening because of congenital shortening. The second group consisted of 23 patients treated for acquired limb deformities. The results in both groups were received in three stages of new bone formation and were based on the appearance of 3 radiographic parameters at the distraction/compression site.Results: The differences between the presence of all radiographic bone parameters in different stages of new bone formation were statistically signficant in both groups, especially the presence of the cortical margin in the first group (Cochran Q = 34.43, df = 2, p = 0.00000). The comparative analysis between the two groups showed a statistically significant difference in the presence of initial bone elements and cystic formations only in the first stage.Discussion and Conclusions: Almost no statistical significance in the differences between both groups of patients with regard to 3 radiographic parameters in 3 stages of new bone formation, indicates a minor influence of the etiopathogenetic background on the new bone formation in patients treated by gradual lengthening or correction of limb deformities.

Background: The aim of this study is to affirm the importance of operative treatment of severe dysplastic coxarthrosis through analysis of the results of implantation of total cementless endo-prothesis in patients with DDH Crowe types III and IV. Patients and methods: This retrospective study involved 28 patients (30 hips) with dysplastic coxart-hrosis, in whom an implantation of cementless total hip endoprothesis was performed at the University Clinic for Orthopaedic Surgery in Skopje. In 26 of the patients the involvement was unilateral and in two patients it was bilateral. The inclusion criterion was radiographically proved severe hip dysplasia Crowe types III and IV. Twenty-one of the patients were female and 7 male, and age distribution was in an interval from 30 to 65 years. The ingrowth of the implant was evaluated using the clinical method, native radiographs and radioisotopic examination with Tc99m. The follow-up period lasted 5 years, and the results were evaluated using the Harris hip score system. Results: 19 of the patients presented an excellent result of the operative treatment, there were 8 good results with persistent local pain 6 months postoperatively, in one case a surgical revision and reimplantation of the acetabular cup was performed, while one patient underwent a surgical revision and reimplantation of the femoral stem and in another patient there was nonunion at the place of the subtrochanteric osteotomy. Full weight-bearing without the use of crutches was achieved 3 months postoperatively, and no serious early postoperative complications were registered in our patients. Discussion and conclusions: In the majority of cases in whom a total hip replacement with cemen-tless endoprothesis is performed because of dysplastic coxarthrosis, a sufficient primary fixation both of the acetabular and the femoral component is achieved, unless one-third of the acetabular cup is left uncovered with bone stock. The problems of decreased muscle strength and limping are usually solved by means of physical therapy in a time period of 45 months.