The Measurement of the Oxidative Index of Polyethylene Obtained during Revision Hip Arthroplasty and Assessment of Its Variability Depending on the Degree of Osteolysis, Implantation Time, as Well as the Size and Material of the Utilized Head.

Background/Objectives: Aseptic loosening is the leading cause of late revision in total hip arthroplasty, primarily due to degenerative oxidation of polyethylene components, leading to wear particle formation and periacetabular osteolysis. This study aimed to analyze the oxidation levels in polyethylene liners and cemented cups retrieved from revision surgeries using Fourier-transform infrared spectroscopy (FTIR) and to explore the correlation between oxidation levels and factors such as head size, head material, fixation method, and implant survival time. Methods: Polyethylene liners and cups were analyzed post-revision surgery to assess oxidation levels, which were then compared to periacetabular bone loss measured by the Paprosky classification. This study evaluated the impact of head size (28 mm vs. 32 mm), head material (ceramic vs. metal), and fixation methods on oxidation. The relationship between the mean oxidation index (OI) and implant survival time was also investigated. Results: There was a significant positive correlation between the mean oxidation index of the polyethylene components and the severity of periacetabular osteolysis according to the Paprosky scale. While the mean OI for samples articulating with ceramic heads was lower than for those with metal heads, and the mean OI for samples with a 32 mm head size was lower than for those with a 28 mm size, these differences were not statistically significant. Furthermore, the fixation method did not affect the oxidation index, and no correlation was found between OI and the survival time of the implants. Conclusions: This study confirms a direct correlation between polyethylene oxidation and periacetabular osteolysis in hip replacements, highlighting the importance of material choice and design in potentially reducing the risk of aseptic loosening. Despite the lack of significant differences in oxidation levels based on head material and size, these factors may still play a role in the long-term outcome of hip arthroplasty, warranting further investigation.

An Attempt to Assess the Indications for Reverse Total Shoulder Arthroplasty Based on Biomechanical Analysis.

BACKGROUND: Starting from the 1950s, shoulder arthroplasty has been developing, one consequence of which has been the concept of reverse shoulder arthroplasty (RSA). Initially, it was supposed to be used only in patients with irreversible rotator cuff damage, but it quickly gained more and more indications for use. The aim of the present study was to assess biomechanical, objective indications for RSA in patients with shoulder osteoarthritis (OA) based on an inertial measurement system with electromyography. MATERIAL AND METHODS: 20 patients were qualified to this prospective study, 10 each in a control and experimental group. The study was conducted between August 2020 and October 2021. The experimental group consisted of 9 women and 1 man aged 55 to 85 years old, with osteoarthritis of the shoulder associated with rotator cuff damage. The study utilised the myoMotion inertial sensor system (Noraxon, USA) synchronized with the surface electromyography system Myotrace 400 (Noraxon, USA). RESULTS: Movement phase diagrams were used to assess the movement patterns. To examine the movement pattern in the shoulder, three motor tests can be proposed: flexion-extension, flexion in the scapular plane and abduction-adduction. The observation of trends for the operated limb showed the highest absolute improvement in the group with the greatest impairment of the movement pattern in the initial test. However, on final evaluation, these results were still twice as low as those obtained in the group with the least impairment. CONCLUSIONS: 1. Early qualification of patients with shoulder OA for RSA could mean a greater likelihood of functional and quality-of-life improvement. 2. Movement patterns after RSA may improve, but will probably not return to physiological values.

Chronic, Neglected Medial Subtalar Dislocation with Associated Talar and Calcaneal Fractures. A Case Report.

Subtalar dislocation is a very rare injury that accounts for just approximately 1% of traumatic dislocations. Stan-dard treatment in acute subtalar dislocations is immediate closed reduction and cast immobilization. Early reduction is of key importance and allows avoiding further damage to soft tissues, nerves and blood vessels. Neglected, chronic subtalar dislocations are seen extremely rarely and only a few cases have been reported in the literature to date. Considering the lack of guidelines and very few literature reports relating to the treatment of such injuries, we have decided to present the case of a male patient with a chronic, neglected, closed medial subtalar dislocation of the right foot with associated fractures of the talar and calcaneal bones. The patient was admitted 4 months post trauma to his right ankle joint caused by a fall from a ladder. An open subtalar reduction was performed with arthrodesis of the talocalcaneal joint and the talonavicular joint of the right foot. The treatment was effective and recreated the me-chanical axis of the limb. One year after the surgery, the patient reported no pain and no limitations in everyday functioning, work and activities. At the one-year follow-up, his AOFAS score was 88/100.

Assessment of Microbiological and Clinical Findings of Two-Stage Revision Arthroplasty Performed Due to Prosthetic Joint Infection.

BACKGROUND: Two-stage revision arthroplasty remains the main surgical strategy for the treatment of prosthetic joint infections (PJI). Sonicate fluid culture has improved sensitivity compared to standard periprosthetic tissue culture, but its usefulness is questionable during the second stage of revision arthroplasty. MATERIAL AND METHODS: Twenty-seven patients with prosthetic joint infection were investigated. Tissue and sonicate fluid cultures were examined to detect bacteria on the removed spacer during the second stage of exchange arthroplasty. Microbiological findings were analyzed and patients were assessed within an average of 5 years follow up. RESULTS: Tissue cultures in second-stage revision arthroplasties were positive in 6/27 cases (22.2%) growing CNS in 4 cases (14.8%), Staphylococcus aureus in 1 case (3.7%), and Enterococcus faecalis in 1 case (3.7%). In 3 cases (11.1%) infection was identified as a result of a sonication procedure. Clinical failures at final follow-up were recorded in 4 (14.8%) patients, with reinfection noted in 3 of them. Arthrodesis and spacer exchange followed by suppressive antibiotic therapy were performed in 2 cases. CONCLUSIONS: 1. Tissue cultures remain the gold standard in diagnosis of PIJ although a negative culture does not rule out the presence of bacteria on spacers removed during second stage revision for PJI. 2. Sonication appears to have limited ability to detect persistent infection before reimplantation and was not associated with recurrent infection; however, it can be considered a complementary method that could make it possible to identify new microorganisms and facilitate the selection of appropriate treatment options. 3. The positive results of sonication should be interpreted as the detection of actual pathogens in the light of the clinical, microbiological and histopathological data, especially for patients with immunodeficiency.

Pseudotumor as a Complication of Total Hip Replacement.

Total hip arthroplasty with metal-on-metal bearing is associated with specific complications: local delayed hypersensitivity reaction (ALVAL) to metal particles, osteolysis and the development of pseudotumors. This process results from the low resistance of the metal bearing to abrasion and corrosion, which causes the release of metal ions into the surrounding tissues. This paper presents the case of a 54-year-old man who required revision surgery due to aseptic loosening of the endoprosthesis with a ceramic (TiN)-on-metal bearing. The removed implants were subjected to material analysis. Mean chemical analysis revealed that the main component of the residue samples was titanium, which constituted 65% of the sample weight, followed by calcium (16%), phosphorus (11%) and aluminum (3.8%). The fissures on the insert were a result of trauma caused by the head, with both elements matching in terms of visible damage. More than 50% of the surface of the head had been damaged due to abrasive wear. The transitional area between the normal and completely delaminated TiN coating shows uneven abrasion, a gradual decrease in coating thickness. In conclusion, the use of endoprosthesis heads with TiN ceramic coating involves very low polyethylene wear. The low resistance of TiN ceramic coating to trauma and the fragility of this coating prevent the use of TiN-coated heads in combination with any non-polyethylene hip endoprosthesis inserts.

Reverse Shoulder Arthroplasty in Osteoarthritis Evaluation of the Results.

BACKGROUND: The aging structure of society results in a growing need for treatment of shoulder osteoarthritis. Reverse shoulder arthroplasty (RSA) has been developed to improve the motor function and strength of the shoulder joint without increasing the risk of dislocation. The aim of the study was to assess the change in quality of life and functional assessment of the shoulder joint after RSA in patients with osteoarthritis, based on the Oxford Shoulder Score (OSS) and an assessment of joint mobility parameters. MATERIAL AND METHODS: A total of 10 patients were admitted to our centre for shoulder arthroplasty between August 2020 and October 2021. The assessment of the degenerative changes was based on the Walch classification and the Samelson & Prieto classification. The OSS questionnaire was used to assess function of the affected shoulder joint and pain in each patient. The range of motion in the shoulder joint was assessed in the pre- and postoperative period. A follow-up examination was performed approximately 6 months after surgery. RESULTS: Analysis of the OSS scores revealed a mean value of 46 points preoperatively and 25 points postoperatively. The OSS scores six months after the procedure were an average of 20.5 points lower. A statistically significant improvement was noted in shoulder flexion (mean 37), abduction (42), external rotation (34), and internal rotation (5)(p<0.05). CONCLUSION: Each patient reported reduced pain and demonstrated an increased range of motion in the affected shoulder joint and functional improvement.

The electromyographic activity characteristics of the gluteus medius muscle before and after total hip arthroplasty.

PURPOSE: The clinical outcomes of total hip arthroplasty are influenced by the correct muscle function that determines good, longterm and proper function of the artificial joint. The aim of the study was to analyze the electromyographic activity of the gluteus medius muscle in patients with hip osteoarthritis and after arthroplasty in various static weight bearing conditions, both on the affected and contralateral side. METHODS: The prospective study involved 70 patients qualified for hip replacement. Patients underwent a surface electromyography of the gluteus medius muscle which involved the Trendelenburg test. The normalized results were obtained for both hips, preoperatively and 6 months after arthroplasty. RESULTS: The only muscle activity differences were found at a full load condition of lower limb. In the preoperative assessment, the activity of the gluteus medius muscle was greater on the side qualified for surgery. After arthroplasty and the rehabilitation period, the muscle activity on the operated side decreased and significantly increased on the contralateral side. Detailed analysis of the contralateral side revealed relationship with osteoarthritis. Previous hip arthroplasty of that side resulted in lower muscle activity, similar to fully functional joints. CONCLUSION: The activity characteristics of the gluteus medius muscle vary depending on the condition of the joint, and the characteristics change as a result of the surgical procedure performed on both the operated and contralateral sides. These dependencies should be taken into account in the rehabilitation process, especially at the side opposite to the operated one.

Differences between sexes in the standard and advanced dimensioning of lateral meniscal allografts.

BACKGROUND: There are many different methods of meniscal allograft measurements, which depend on individual tissue bank procedures. Due to the lack of a standardised method of dimensioning, measurement results may vary between individual cases. Consequently, allograft may be mismatched to the patient's knee anatomy. The purpose of this study was to measure four meniscal dimensions - two standard and two specific - and then compare them between sexes. METHODS: Fourteen cadaveric lateral menisci (seven male and seven female) were scanned using a microtomography scanner. The obtained three-dimensional (3-D) models of each meniscus were analysed, taking into account four dimensions: circumference, width, central meniscal concavity, and total meniscal volume. The computer researcher was not informed of the original data of the meniscal samples until the calculations were completed. RESULTS: No statistical between-sex differences were found in the standard dimensions. The specific dimensions, in turn, presented statistically significant between-sex differences (P>0.05). The mean difference between male and female total volume of the meniscus was equal to 36.59%, and the mean difference between male and female central meniscal concavity surface was equal to 31.22%. CONCLUSION: This study found that sex should be taken into account as an important factor during a matching procedure performed by tissue bank staff.

Correction to: Atraumatic femoral neck fracture during bisphosphonate treatment: case report and review of the literature.

Correction to: Aging Clin Exp Res https://doi.org/10.1007/s40520-017-0846-0.

The 13-year observation of hip fracture in Poland-worrying trend and prognosis for the future.

INTRODUCTION: Hip fractures are often considered to be one of the most common osteoporotic fractures. In our previous study, we noted the increasing trend in the total number of hip fractures as well as crude and standardized rates, for both women and men. This observation enabled us to delve deeper into the study of osteoporotic fractures. METHODS: Hospital records between 1.01.2002 and 31.12.2014 with ICD-10 codes S72.0. S72.1 and S72.2 (femoral neck. intertrochanteric, subtrochanteric, and inter and subtrochanteric fracture) were analysed. All fractures occurred in citizens who lived in the district Tarnowskie Góry and the city of Piekary Slaskie aged 50 years and more. RESULTS: 1507 fragility hip fractures (400 in men, and 1107 in women) were registered. The rates increase in both sexes was still observed. The tendency to sustain fractures was lower in female (29.3%) than in the male population (63.6%). We observed a lower increase in urban (35.8%) population when compared to rural (40.8%) population. Incidence rate ratios for female gender were 1.89 (95% CI 1.65-2.18). The rates in 2014 were as follows: crude rate of 216.2 (men 140.9; women 276.5) and standardized 183.9 (131.6 and 219.4, respectively). This observation allowed as to project a total crude rate of 467.2 (men 329.6; women 584.7) for the year 2050. CONCLUSIONS: The number of osteoporotic hip fractures in Polish men and women is still relatively low, but the epidemiological situation is getting worse. The over 13 years of follow-up demonstrated that the trend to increase in total number of hip fractures for men and women is still observed. This prognosis is of a major concern.

Notch signaling pathway and gene expression profiles during early in vitro differentiation of liver-derived mesenchymal stromal cells to osteoblasts.

Notch signaling is a key signaling pathway for cell proliferation and differentiation. Therefore, we formulated a working hypothesis that Notch signaling can be used to detect early osteoblastic differentiation of mesenchymal stromal cells. Changes in expression and distribution of Notch 1, 2, 3, and Delta1 in the cytoplasm and nuclei of rat liver-derived mesenchymal stromal cells differentiating into osteoblasts were investigated, together with the displacement of intracellular domains (ICDs) of the receptors. In addition, an oligonucleotide microarray was used to determine the expression of genes known to be linked to selected signaling pathways. Statistically significant changes in the number of cells expressing Notch1, Notch2, and Delta1, but not Notch3, and their activated forms were detected within 24 h of culture under osteogenic conditions. Although the number of cells expressing Notch3 remained unchanged, the number of cells with the activated receptor was significantly elevated. The number of cells positive for Notch3 was higher than that for the other Notch receptors even after 48 h of differentiation; however, a smaller fraction of cells contained activated Notch3. Culture mineralization was detected on day 4 of differentiation, and all analyzed receptors were present in the cells at that time, but only Delta1 was activated in twice as many cells than that before differentiation. Thus, the three analyzed receptors and ligand can serve as markers of very early stages of osteogenesis in stromal cells. These early changes in activation of the Notch signaling pathway were correlated with the transcription of several genes linked to osteogenesis, such as Bmps, Mmps, and Egfr, and with the regulation of cell cycle and apoptosis.

Factors Influencing Treatment of Proximal Femoral Fractures.

BACKGROUND: Orthopaedics and traumatology departments are dominated by patients with proximal femoral fractures, who represent 20-30% of all patients treated there. The aim of this study was identification and evaluation of factors influencing treatment of proximal femoral fractures. MATERIAL AND METHODS: Between 2008 and 2015, we treated 424 femoral neck fractures and 442 trochanteric fractures in patients over 40 y/o. The impact of fracture location (femoral neck/trochanteric), character (non-displaced/displaced) and the patient's general condition (metrical/biological age, health condition) on qualification and treatment used (fixations/hip pro-sthesis/non-operative) was analyzed. RESULTS: The results show a significant impact of factors such as type of fracture and general health condition on treatment method selection (mainly in femoral neck fractures). The distinction between non-displaced and displaced fractures is significant in preoperative qualification. For displaced femoral neck fractures, total hip replacement (non-cemented) was performed in patients between 55 and 65 y/o, while total hip replacement (cemented) and hemiarthroplasty (bipolar/Austin Moore's) in patients between 75 and 90 y/o. In lateral fractures of the femoral neck, mostly total hip replacement and occasionally proximal femoral nail fixation was performed. The importance of qualification factors was much lower in preoperative qualification of trochanteric fractures, where internal fixation remains the primary method of treatment and total hip replacement was only used in patients with co-existing coxarthrosis. CONCLUSIONS: 1. The biggest impact on selection of femoral neck fractures treatment method was exerted by the degree of displacement of bone fragments, age and the patient's pre-injury walking status. 2. Besides general condition, the presence of coxarthrosis was the most important factor influencing trochanteric fracture treatment method.

Identification of Asymptomatic Prosthetic Joint Infection: Microbiologic and Operative Treatment Outcomes.

BACKGROUND: This prospective study investigated the role of mechanical and biological factors in aseptic implant loosening or presumed silent prosthetic joint infection (PJI). METHODS: Thirty-seven patients were investigated. Microbiologic and molecular methods were used to detect bacteria on the surface of the failed implants removed during revision arthroplasty. Histopathologic analysis was performed. The influence of body mass index (BMI) and various co-morbidities on implant failure also was determined. RESULTS: The results of sonicated fluid cultures were positive for bacteria in 29.7% and the results of intra-operative tissue and joint liquid cultures in 18.9% and 16.2%, respectively. Molecular detection with 16S rRNA sequencing revealed a large variety of bacteria. The most frequent organism was coagulase-negative Staphylococcus (CNS). The outcomes of histopathologic tests of peri-prosthetic tissue showed evidence of the infection type in all culture-positive joints and in 41.4% of the cases with negative culture results. Overweight status or obesity was present in 82.8% of the culture-negative patients. CONCLUSIONS: The results of this study proved the presence of micro-organisms on the surface of implants in both aseptic and presumed PJI cases. Inclusion of the sonication procedure in the diagnostic algorithm increased the ability to identify the pathogen. The results of our study suggest the co-existing roles of BMI and the time to implant loosening as well as biological agents in causing prosthesis loosening.

Do we need orthogeriatrics in Poland? Changes in the age structure and location of hip fractures.

BACKGROUND: Patients with hip fractures present a great challenge for surgeons due to multimorbidity, polypharmacy as well as difficulty in communicating. These could be attributed to a recent trend in the aging patient population (80 years and older) as compared to the past. The aim of this study is to analyze age structure and location in male and female patients' population with hip fracture over 50. MATERIALS AND METHODS: Hospital records between 2005 and 2014 with ICD-10 codes S72,0, S72,1 and S72,2 were included in the analysis. All fractures occurred in citizen aged 50 years and over living in the district of Tarnowskie Góry and the city of Piekary Slaskie in Poland. RESULTS: Within the study period, 1258 hip fractures were registered. The mean age of the patients was higher every year, starting from 77.27 ± 9.52 in 2005 to 80.80 ± 9.65 years in 2014 (p < 0.01). The average age also increased in both gender groups from 73.85 ± 8.30 to 77.89 ± 9.52 years in male and from 78.14 ± 9.66 to 81.98 ± 9.49 years in female, respectively. The median age value was changed from 78.00 to 83.00 years in the total population. We noted a significant increase in female with trochanteric fracture; however, the level of neck fracture was almost the same. In men, crude rates for both trochanteric and cervical fractures slightly increased. CONCLUSIONS: As the age of patients increases, fractures were shown to be more complicated. Given the scale of the phenomenon and its determinants, we emphatically conclude orthogeriatrics is needed in Poland.

Kinematic gait parameters changes in patients after total knee arthroplasty. Comparison between cruciate-retaining and posterior-substituting design.

PURPOSE: The patients expect optimal knee function after Total Knee Arthroplasty. It is necessary to apply appropriate surgical technique and supervised physical therapy. The optimal management of posterior cruciate ligament remains controversial. Both implant designs, i.e., cruciate retaining and posterior substituting, allow the orthopedic surgeon to achieve excellent clinical outcomes, as measured by commonly used questionnaires. Such methods of assessment may poorly reflect the functional status of patients. Therefore, three-dimensional gait analysis is recommended to evaluate the outcomes of surgical intervention. This study sought to determine differences in kinematic gait parameters and Knee Society Score between cruciate-retaining and posterior-substituting patients. METHODS: 23 individuals after cruciate-retaining total knee arthroplasty and 19 individuals after posterior-substituting total knee arthroplasty were subjected to gait analysis using three-dimensional motion capture system BTS Smart DX 7000. In addition, gait was assessed in 21 patients with knee osteoarthritis and in 30 healthy individuals. RESULTS: The study did not reveal differences between cruciate-retaining and posterior-substituting groups, both in terms of Knee Society Score and kinematic gait parameters. There were also no differences in kinematic gait parameters between patients from the knee osteoarthritis group and total knee arthroplasty groups. The analyzed parameters in all of the groups differed significantly from those found in healthy individuals. CONCLUSIONS: Surgical technique and implant design do not affect values of kinematic gait parameters evaluated under natural walking speed. Several months after surgery the patients still demonstrated alterations in gait pattern, similar to those recorded in patients with knee osteoarthritis.

Comparison of cultures and 16S rRNA sequencing for identification of bacteria in two-stage revision arthroplasties: preliminary report.

BACKGROUND: The use of a prefabricated spacer in two-stage revision arthroplasty remains one of the few surgery strategies for infected-joint arthroplasty treatment, despite the many unidentified microorganisms in the infected joint replacements reported in some recent studies. The aim of this prospective survey was to investigate if the sonication followed by polymerase chain reaction (PCR) can improve bacterial identification on the surfaces of prefabricated spacers and if the systemic laboratory mediators of infection and positive microbiological results can take a role of predictive factors of infection and clinical failures in 2-years follow-up. METHODS: Thirteen patients with prosthetic joint infection were investigated. Bacterial culture and deoxyribonucleic acid (DNA) sequencing were used to detect bacteria on the surface of prefabricated spacers removed during the second stage of revision arthroplasty. The results of pre- and intraoperative culture and DNA sequencing were compared. Minimum follow-up was 2 years. RESULTS: The result of tissue cultures in second-stage revision arthroplasties revealed positive results in 15 % of patients with Coagulase-negative Staphylococci (CNS) growth. Bacterial DNA was found in over 90 % of patients with negative synovial fluid culture. Positive PCR results revealed potential pathogenic bacteria and species of human and environmental microflora with low virulence. Clinical failures at final follow-up were recorded in 2 (16.6 %) patients. CONCLUSION: The lack of clinical signs of infection, negative culture of preoperative joint aspirate, and intraoperative specimens do not exclude the presence of bacteria on the surfaces of spacers. The positive results of sonication and molecular tests should be interpreted as real pathogenicity factors in the light of the clinical and laboratory data, especially for patients with immunodeficiency. We confirmed our previous results that sonication followed by PCR and sequencing improved bacterial identification.

Variation in the Posterior Condylar Angle.

BACKGROUND: Clinical success of TKR depends to a large extent on the correct positioning of the implants. The femur cut is usually made in 3° of external rotation relative to the posterior aspect of the femoral condyles, which is a typical value of the Posterior Condylar Angle (PCA). The aim of this study was to assess variation in the PCA and to identify possible correlations between the value of the PCA and the following parameters: gender, body side, body height and weight (BMI). MATERIAL AND METHODS: The study group comprised 75 patients who underwent an Angio-CT study between 2012 and 2014 due to a suspected vascular disorder. For each knee, we measured the Posterior Condylar Angle and the Posterior Twist Angle. RESULTS: The mean Posterior Condylar Angle was 2.7±2.1°. The differences between males and females were not statistically significant. The angles showed a high degree of symmetry between the contralateral knees. CONCLUSIONS: 1. Positioning of the femoral component of the knee joint endoprosthesis parallel to the transepicondylar line requires resecting the femur at approximately 3° of external rotation relative to the line tangential to the posterior aspect of the femoral condyles. This angle, however, may vary from 3.6° of internal rotation to 9.0° of external rotation which should be taken into consideration by the operating surgeon. 2. The values of the Posterior Condylar Angle do not correlate with gender, age, Body Mass Index and body side (with notable, near-perfect symmetry between the contralateral limbs). 3. In female patients, height and body weight may influence the Posterior Condylar Angle, but these correlations would require further studies of larger groups of patients. In male patients, we were unable to find such correlations.

Osteitis in the Course of Pyodema Gangrenosum. Case Raport.

We present the case of a male patient admitted to the Department of Orthopaedics and Musculoskeletal Traumatology, Medical University of Silesia (MUS) in Katowice, due to a right hindfoot abscess with calcaneal infiltration and pain in the forehead and the back, with evidence of local inflammation. The patient had a history of ulcerative colitis and sclerosing cholangitis was suspected. During the hospital stay, the patient underwent calcaneal CT, surgery (resection of an inflammatory focus) and MRI of the thoracic and lumbosacral spine, which revealed inflamed spinous processes of the Th10, Th11 and Th12 vertebrae. Numerous cultures and histo-pathological examinations were performed. Specialist consultations were obtained. The differential diagnosis included myeloproliferative and lymphoproliferative processes as well as skin and soft tissue neoplasms. The clinical presentation and examination results led to a diagnosis of pyoderma gangrenosum and the patient was referred to the Department of Internal Medicine and Rheumatology of the MUS to undergo further treatment.

Gait analysis in patients after unilateral hip arthroplasty.

BACKGROUND: Osteoarthritis (OA) is the most common joint pathology and the main cause of disability in elderly persons. Arthroplasty still remains the most effective treatment of OA. Routine post-operative patient assessment does not include an objective functional examination leading to conclusions regarding the need of further rehabilitation. This role is played by gait analysis performed in patients after arthroplasty. The aim of the study was to conduct a quantitative and qualitative analysis of selected gait parameters in patients after unilateral cementless hip arthroplasty. MATERIAL AND METHODS: The study involved a group of 16 patients who were examined before and after hip arthroplasty. Gait analysis was conducted before surgery and at least 6 months after the procedure. The Smart DX BTS system for spatial gait analysis was used. RESULTS: The duration of the stance phase on the affected side was 63.8 [% gait cycle] and was significantly shorter (p<0.05) than the phase on the unaffected side, with a duration of 69.4 [% gait cycle]. After surgery, the duration of swing phase on the unaffected side increased (p<0.05) from 30.6 to 35.1 [% gait cycle]. A statistically significant change was also found in the double support phase (the arthrotic limb as the front limb), which was markedly shortened. The average length of a single and double step, cadence, average gait velocity, and the velocity of leg swing in the swing phase increased. The range of hip mobility increased in all planes, especially in the sagittal plane. CONCLUSION: The space and time gait parameters with regard to the operated leg after hip arthroplasty indicate an improvement as compared with the baseline results; however, they do not reach the values found in healthy persons.