Head Prosthesis Research Articles

Enhancing the Tribological Properties of Bearing Surfaces in Hip Arthroplasty by Shot-Peening the Metal Surface

Total hip arthroplasty (THA) is a surgical procedure for patients with pain and difficulty walking due to hip osteoarthritis. In primary THA, the acetabulum and femoral head are replaced by a prosthesis where the modular femoral head and inner liner of the acetabulum form the bearing surface. The most popular bearing surface used in the United States, metal-on-polyethylene, consists of a cobalt–chromium molybdenum (CoCrMo) alloy femoral head that articulates with a polyethylene acetabular liner, typically made of highly cross-linked polyethylene. While successful in most cases, THA sometimes fails, commonly from aseptic loosening due to the wear debris of polyethylene. Fine-particle shot peening (FPSP) is a simple method for enhancing the mechanical properties and surface properties of metal, including reducing friction and enhancing the lubrication properties of the metal surface. In this study, we applied FPSP to the CoCr in the femoral head of a hip prosthesis to improve its surface properties and conducted experiments with pin-on-disc tribometers using CoCr as a pin and highly cross-linked polyethylene as a disc to mimic the THA implant. The results show that FPSP significantly enhances the tribological properties of the CoCr surface, including lubrication; decreases the friction coefficient; and decreases the polyethylene wear volume.

Is Heterotopic Ossification Removal From Alloplastic Temporomandibular Joint Prosthesis Using Er,Cr:YSGG Laser Superior to Conventional Methods?

Heterotopic ossification (HO) formed over the major components and fixation screw heads of an alloplastic temporomandibular joint replacement (TMJR) prosthesis can result in decreased quality of life, limited function, prosthesis failure, and hinder prosthesis revision, replacement, or removal. This study simulated HO removal from the major components and fixation screw heads of alloplastic TMJR prostheses using an erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser and compared the results to conventional methods of HO removal. The surface morphology and chemical structure of the exposed components were analyzed. The investigators hypothesize that HO removal with an Er,Cr:YSGG laser causes less damage to TMJR prosthesis components compared to conventional HO removal methods. This multiple test descriptive analysis simulated HO removal from TMJR prostheses mounted to stereolithic models. Simulated HO removal was completed using a novel Er,Cr:YSGG laser method and conventional methods which utilized a fissure carbide bur in a high-speed rotary instrument, a standard osteotome, and an ultrasonic aspirator. Surfaces exposed on the TMJR prostheses were analyzed for morphological or chemical change using scanning electron microscopy, energy dispersive X-ray spectroscopy, and Raman spectroscopy. The Er,Cr:YSGG laser did not adversely affect the titanium screws or titanium components of the TMJR prostheses, while conventional methods of HO removal did. HO removal using the Er,Cr:YSGG laser and conventional methods both inflicted surface damage to the fossa ultrahigh molecular weight polyethylene component of the TMJR prostheses. Damage inflicted to titanium alloy or commercially pure titanium components of TMJR prostheses by conventional HO removal methods can be avoided by instead removing HO with an Er,Cr:YSGG laser. However, long exposure of the Er,Cr:YSGG laser to ultrahigh molecular weight polyethylene surfaces should be avoided. Additional research to expand on applications to other procedures and in other surgical fields is encouraged.

Is Heterotopic Ossification Removal from Alloplastic Temporomandibular Joint Prosthesis Using Er,Cr:YSGG Laser Superior to Conventional Methods?

Heterotopic ossification (HO) formed over the major components and fixation screw heads of an alloplastic temporomandibular joint replacement (TMJR) prosthesis can result in decreased quality of life, limited function, prosthesis failure, and hinder prosthesis revision, replacement, or removal. This study simulated HO removal from the major components and fixation screw heads of alloplastic TMJR prostheses using conventional methods versus HO ablation with an erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG) laser.

Is There Any Difference Between a Spherical Marker and a Simple Coin for Hip Replacement Digital Planning?

Objective To evaluate the accuracy and differences between 2 types of metallic markers, sphere, and coin, for radiographic calibration in the preoperative planning of hip arthroplasty. Methods Four spherical metallic markers and four coins, both 25 mm in diameter, were placed on the greater trochanter, pubic symphysis, between the thighs, and on the table of the exam, for radiographic examination of the hip in 33 patients with hip prosthesis. The prosthesis head was used for calibration and two examiners measured the markers' image diameters, and the results were analyzed statistically. Results In the greater trochanter, the sphere and the coin were not visualized in 19 radiographs (57.6%). Between the thighs, the coin marker was not visualized in 13 radiographs (39.4%). In the greater trochanter, the 25-mm accuracy of the coin and the sphere was, respectively, between 57.1 and 63.3% and between 64.3 and 92.9%. The coin between the thighs reached 25-mm accuracy in between 50 and 60% of cases. Over the exam table, the coin and sphere markers reached, respectively, the mean diameters of 22.91 mm and 23 mm, the lowest coefficient of variation, the lowest confidence interval, and the easiest positioning. There was statistical difference between the evaluations of the markers (coin vs. sphere) in all positions ( p < 0.032), except for the exam table position ( p = 0.083). Conclusions The coin between the thighs is the best marker for radiographic calibration in the preoperative planning of hip arthroplasty, and we suggest the use of another coin on the exam table for comparison, considering the 8% reduction in relation to its real size.

Evaluation of results of fracture head and neck of radius managed by varius methods

Radial head fractures are the most frequent fracture type reported around the elbow. Fractures have been documented to occur in isolation or with other associated osseous and soft tissue injuries. However, despite intensive research into these injuries, controversies still exist regarding the role of further imaging modalities, the use of non-operative management, as well as the indication and technique for operative intervention. To analyses the clinical and functional outcome of patients with head and neck fracture of radius managed by conservative method, open reduction and internal fixation, radial head prosthesis and radial head excision. This study “evaluation of results of fracture head and neck of radius managed by various methods” was carried out in M.K.C.G Medical College, Berhampur from September 2017 to October 2019. Eighty patients of radial head and neck fractures were treated and hereby included in our study. We collected records of the patients by asking the patients history and examining the patients. Essential investigations of all the patients were done. The primary outcome measures were the surgeon reported Mayo Elbow Score (MES) and the patient reported Short Musculoskeletal Function Assessment (SMFA). Current evidence supports open reduction and internal fixation of simple Mason type II fractures. For Mason type III fractures, controversy still exists regarding the optimal treatment. Studies currently show good to excellent results with radial head replacement in the majority of patients with Mason type III fractures with three or more fracture fragments.

Do SiNx coatings bear the potential to reduce the risk of micromotion in modular taper junctions?

Fretting corrosion is one contributor to the clinical failure of modular joint arthroplasty. It is initiated by micromotion in metal junctions exposed to fluids. Omitting metal-on-metal contacts could help to reduce the corrosion risk. The coating of one metal taper partner with a ceramic-based silicon nitride (SiNx) coating might provide this separation. The aim of the study was to identify whether a SiNx coating of the male taper component influences the micromotion within a taper junction. Hip prosthesis heads made of CoCr29Mo6 (Aesculap) and Ti6Al4V (Peter Brehm) were assembled (2000 N) to SiNx-coated and uncoated stem tapers made of Ti6Al4V and CoCr29Mo6 (2×2×2 combinations, each n = 4). Consecutive sinusoidal loading representing three daily activities was applied. Contactless relative motion in six degrees of freedom was measured using six eddy-current sensors. Micromotion in the junction was determined by compensating for the elastic deformation derived from additional monoblock measurements. After pull-off, the taper surfaces were microscopically inspected. Micromotion magnitude reached up to 8.4 ± 0.8 µm during loading that represented stumbling. Ti6Al4V stems showed significantly higher micromotion than those made of CoCr29Mo6, while taper coating had no influence. Statistical differences in pull-off forces were found for none of the taper junctions. Microscopy revealed CoCr29Mo6 abrasion from the head taper surface if combined with coated stem tapers. Higher micromotion of Ti6Al4V tapers was probably caused by the lower Young's modulus. Even in the contact areas, the coating was not damaged during loading. The mechanics of coated tapers was similar to uncoated prostheses. Thus, the separation of the two metal surfaces with the objective to reduce in vivo corrosion appears to be achievable if the coating is able to withstand in vivo conditions. However, the hard ceramic-based stem coating lead to undesirable debris from the CoCr29Mo6 heads during loading.

Using artificial neural networks to predict impingement and dislocation in total hip arthroplasty

Dislocation after total hip arthroplasty (THA) remains a major issue and an important post-surgical complication. Impingement and subsequent dislocation are influenced by the design (head size) and position (anteversion and abduction angles) of the acetabulum and different movements of the patient, with external extension and internal flexion the most critical movements. The aim of this study is to develop a computational tool based on a three-dimensional (3D) parametric finite element (FE) model and an artificial neural network (ANN) to assist clinicians in identifying the optimal prosthesis design and position of the acetabular cup to reduce the probability of impingement and dislocation. A 3D parametric model of a THA was used. The model parameters were the femoral head size and the acetabulum abduction and anteversion angles. Simulations run with this parametric model were used to train an ANN, which predicts the range of movement (ROM) before impingement and dislocation. This study recreates different configurations and obtains absolute errors lower than 5.5° between the ROM obtained from the FE simulations and the ANN predictions. The ROM is also predicted for patients who had already suffered dislocation after THA, and the computational predictions confirm the patient’s dislocations. Summarising, the combination of a 3D parametric FE model of a THA and an ANN is a useful computational tool to predict the ROM allowed for different designs of prosthesis heads.

Effect of Coating Materials on the Fatigue Behavior of Hip Implants: A Three-dimensional Finite Element Analysis

This study aims to validate, using finite element analysis (FEA), the design concept by comparing the fatigue behavior of hip implant stems coated with composite (carbon/PEEK) and polymeric (PEEK) coating materials corresponding to different human activities: standing up, normal walking and climbing stairs under dynamic loadings to find out which of all these models have a better performance in the prosthesis-bone systems. A 3D finite element models of hip implants, femur, coating layers with polymeric (PEEK) and composite (carbon/PEEK) coating materials are created for FEA. The cyclic loads are applied on the prosthesis head. Fatigue life durations are calculated based on the Goodman mean-stress fatigue theory. The fatigue safety factor for the coated implant is increased more than 12.73% at least compared to the uncoated implant. The carbon/PEEK composite material with 0, +45, -45, and 90 degrees fiber orientation (configuration I) has the highest fatigue life and fatigue safety factor. The numerical result show that the carbon/PEEK composite material (configuration I) seems to be a good solution to increase the values of fatigue safety factor of coating layers due to highest fatigue life and fatigue safety factor. It distributes the applied load and transfers it to the bone, reducing stress-shielding effects and prolong the bone-prosthesis system life span.

Simulation of the Behavior of a Cracked Head of Shoulder Prosthesis

Simulation of the Behavior of a Cracked Head of Shoulder Prosthesis

Numerical study of stress shielding evaluation of hip implant stems coated with composite (carbon/PEEK) and polymeric (PEEK) coating materials.

The forces applied to the prosthesis during human activity produce dynamic stresses varying in time and may causing stress shielding in prosthesis-bone system. Therefore, it is important to reduce stress shielding effect. This study aimed to investigates, using finite element analysis, how a PEEK and carbon/ PEEK composite coating materials on a titanium alloy hip implant stem could reduce stress shielding effect corresponding to different human activities: standing up, normal walking and climbing stairs under dynamic loadings to find out which of all these models have a better performance. A 3D finite element model of femur, hip implants, coating layers with composite (carbon/PEEK) and polymeric (PEEK) coating materials were constructed for finite element analysis. A time-dependent cycling load was applied on the prosthesis head. The maximum increase in load transfer to the bone was 207% for the prosthesis coated with carbon/PEEK configuration I (fibers orientated with 0, +45, -45, and 90 degrees) in average compared to uncoated one. Numerical result showed that the carbon/PEEK composite material (configuration I) seems to be a good solution to distribute the applied load and transfer it to the bone, thus to reduce stress shielding problems and to prolong lifetime of the prosthesisbone system. It will prevent aseptic loosening and enhance the stability of the system

STAGED SURGICAL RECONSTRUCTION OF MASSIVE PELVIC DEFECT

Purpose of the study — to illustrate on a particular clinical case an option of treatment for patients with severe pelvic defects by a staged surgery: vascularized bone grafting and revision arthroplasty using custom made implant produced by laser sintering based on layered 3D-visualisation. Material and Methods. Female, 61 years old, was admitted to clinic in 2016 with aseptic loosening of acetabular component and polyethylene insert wear following arthroplasty with total cementless prosthesis. Revision arthroplasty was made with hemispherical augment and anti-protrusion ring. On day 7th after the surgery a dislocation of prosthesis head, pubic bone fracture, migration of acetabular component and bone defect with pelvic discontinuity occurred due to trauma. To restore continuity of the pelvic ring and supportability of the lower limb the authors performed a staged multisession procedure: removal of prosthesis, free vascularized bone grafting by costal vascular pedicle graft and plating fixation of the pelvis. 6 months after the first stage a custom made prosthesis was implanted. Such prosthesis was produced based on a 3D pelvis reconstruction model by layered visualization and with evaluation of bone density on the Hounsfield scale and was printed on 3D-printer by laser sintering from LPW-TI64-GD23-TYPE5 titanium. Results. The authors did not observe any septic complications, dislocations and components migration in the early postoperative period. Function was assessed by Harris Hip Score. Scores prior to arthroplasty by a custom made implant was 12 points, one month postoperatively — 30 points, three months postoperatively — 51 points, six months postoperatively — 74 points. Life quality scores by SF-36 were reported as follows: prior to surgery РН — 21.32; МН — 40.92; one month postoperatively РН — 40.66; МН — 55.80; three months postoperatively РН — 52.14; МН — 57.81; six months postoperatively РН — 62.46; МН — 72.08. Conclusion. Vascularized bone autoplasty allows to restore pelvic continuity, and the use of custom made implants — to restore supportability of the lower limb and hip function in case of an extensive pelvic defect.

IMPACT OF VARIOUS FACTORS ON THE POLYETHYLENE WEAR RATE IN TOTAL HIP ARTHROPLASTY

Purpose of the study — to determine the rate of polyethylene wear in hip arthroplasty depending on various factors and to evaluate a correlation of wear rate and motor activity of the patient.Material and methods. 467 patients with coxarthrosis were included in the study with gender distribution of 322 (35.8%) women and 145 (31.0%) men. Mean age of patients was 55.0 years without statistically significant variances in women and men (р = 0,743). Daily motor activity of 167 patients (35.8%) was assessed using pedometer. The authors evaluated prosthesis head displacement in relation to the center of acetabulum and calculated the rate of polyethylene wear in MediCad. Modified Harris Hip Score and VAS parameters were evaluated for all patients. All data was analyzed and statistical processed.Results. Average level of motor activity was more than 1.9 million steps per year. The overall rate of polyethylene wear depended on the follow up period, the Pearson correlation coefficient r = 0.297 (р0,001). Mean wear rate was 0,16 mm/year (95% CI 0.15–0.17). At the same time wear rate significantly differed in the groups of standard and cross-link polyethylene, namely 0.18 mm/year (95% CI 0.17–0.19) and 0.11 mm/year (95% CI 0.1–0.11) (р0.001). The authors identified the following additional factors affecting wear rate in the present study: cup inclination angle, r = 0.241 (р = 0.002), and the level of motor activity, r = 0.574 (р0.001). No evident correlation of wear rate to age, r = 0.14 (р = 0.859), and to BMI, r = -0.094 (р = 0.226), was identified, which apparently is due to a strong impact of mixing factors. Patients’ satisfaction with treatment outcomes was assessed by VAS score and in average was 91,1 points (95% CI 90.3–91.9). Harris Hip Score parameters improved in average from 36.5 (95% CI 35.1–37.9) up to 91.6 points (95% CI 91.1–92.0).Conclusion. Out of the multiple factors affecting the polyethylene wear rate only the inclination angle of acetabular component and a higher level of patient motor activity have proven to be statistically significant.

Enhanced lubricant film formation through micro-dimpled hard-on-hard artificial hip joint: An in-situ observation of dimple shape effects.

This study evaluates the impact of dimple shapes on lubricant film formation in artificial hip joints. Micro-dimples with 20-50 µm lateral size and 1 ± 0.2 µm depths were fabricated on CrCoMo hip joint femoral heads using a picosecond laser. Tribological studies were performed using a pendulum hip joint simulator to apply continuous swing flexion-extension motions. The results revealed a significantly enhanced lubricant film thickness (≥ 500 nm) with micro-dimpled prosthesis heads at equilibrium position after the lubricant film has fully developed. The average lubricant film thickness of dimpled prostheses with square- and triangular-shaped dimple arrays over time is about 3.5 that of the non-dimpled prosthesis (204 nm). Remarkably, the prosthesis with square-shaped dimple arrays showed a very fast lubricant film formation reaching their peak values within 0.5 s of pendulum movement, followed by prosthesis with triangular-shaped dimple arrays with a transition period of 42.4 s. The fully developed lubricant film thicknesses (≥ 700 nm) are significantly higher than the surface roughness (≈ 25 nm) demonstrating a hydrodynamic lubrication. Hardly any scratches appeared on the post-experimental prosthesis with square-shaped dimple array and only a few scratches were found on the post-experimental prosthesis with triangular-shaped dimple arrays. Thus, prostheses with square-shaped dimple arrays could be a potential solution for durable artificial hip joints.

Optimizing total hip replacement prosthesis design parameter for mechanical structural safety and mobility

Femoral acetabular impingement after total hip replacement reduces range of motion (ROM), which leads to dislocation or subluxation problems. Decreasing the head and neck diameters of the hip prosthesis largely influences ROM, but reduced neck diameters increases principal stress. The purpose of study was to develop a design optimization framework for neck diameter to maximize range of motion while simultaneously minimizing the stress throughout the neck cross section. A proximal femur with a hip prosthesis model was developed, and the principal stress was calculated. To optimize the neck diameter, a multi-objective function was developed which minimizes principal stress at the neck while maximizing ROM. Stress was calculated using finite element method, and ROM was mathematically calculated. In this study, neck diameters were optimized for head diameters. A linear equation to calculate optimum neck diameter with respect to the head diameter was proposed. The principal stress of the modified model decreased by 33.6% while maintaining acceptable range of motions. Results show that design parameters, including the neck diameter, head diameter, and neck-to-shaft angle, have trade-off relationships between principal stress and ROM. Therefore, careful determination of the neck diameter is needed to provide adequate mechanical safety and mobility in the THR prosthesis.

Optimizing Ossicular Prosthesis Design and Placement.

Middle ear hearing reconstruction is unpredictable. Difficulties arise because of host factors, such as ventilation or scarring, surgical technique factors, such as prosthesis placement and stabilization, and design and mechanical factors influencing the properties of the prosthesis. Often there is a balancing act between choosing optimal stability, and maximizing the mechanical vibrations of the prosthesis. We review our and other investigators' work, in design and ideal placement of middle ear prostheses. Middle ear prostheses need to be rigid enough to deliver acoustic forces without bending. Prosthesis mass has a modest effect at higher frequencies. A key point is that rotational movements of the prosthesis have to be constrained. Prosthesis head size and cartilage interposition, within reason, have little effect on vibration transmission. Reconstruction to the malleus may have some small mechanical advantage; however this is not clearly proven. Similarly, there is no proven advantage in reconstructing to the stapes head instead of the footplate. The most important factor for good long term results is probably the stability of the prosthesis, both to acute inertial forces such as trauma, and to slower term changes such as tympanic membrane position and scarring contractures.

Cuff tear arthropathy shoulder hemiarthroplasty: a radiographic outcome study.

Cuff tear arthropathy (CTA) head prosthesis has recently become an alternative to standard shoulder hemiarthroplasty in patients with severe cuff disease by offering an increased surface area and decreased impingement. The purpose of this study is to evaluate the radiographic outcomes of CTA prosthesis and to correlate them with clinical outcomes. In this retrospective study of CTA hemiarthroplasties over an 11-year period, two radiologists reviewed pre-/postoperative radiographs and clinical data. Radiographic complications were correlated with subsequent surgery using Cox regression models. Rates of surgical revision and radiographic complications over time were estimated using Kaplan-Meier curves. Ninety-seven CTA hemiarthroplasties were identified in 92 patients (5 bilateral) with a mean patient age of 68.7years. Mean radiographic follow-up was 12months with a mean of 3.3 radiographs per prosthesis. Twenty-six arthroplasties (26.8%) experienced at least one radiographic complication, including acromion remodeling (19.5%), anterior-posterior subluxation (5.2%), periprosthetic fracture (4.1%), glenoid remodeling (3.1%), hardware loosening (2.1%), superior subluxation (2.1%), and subsidence (1.0%). Eight cases underwent revision surgery (8.2%). The occurrence of a postoperative radiographic complication was associated with increased risk of surgical revision (hazard ratio 11.5, 95% CI: 2.4-55.7, p = 0.002); 73.5% of radiographic complications occurred by 3months after the initial surgery (complication rate of 23.3%) based on Kaplan-Meier curve analysis. Radiographic complications after CTA head hemiarthroplasty are common with most occurring by 3months after surgery and are highly associated with surgical revision.

Accelerating fully phase-encoded MRI near metal using multiband radiofrequency excitation.

To develop a multiband radiofrequency (RF) excitation strategy for simultaneous excitation of multiple RF offsets to accelerate fully phase-encoded imaging near metallic prostheses. Multiband RF excitation was designed and incorporated into a spectrally resolved fully phase-encoded (SR-FPE) imaging scheme. A triband (-6, 0, 6 kHz) acquisition was compared with three separate single-band acquisitions at the corresponding RF offsets with a phantom containing the head of a hip prosthesis. In vivo multiband data with continuous spectral coverage were acquired in the knee of a healthy volunteer with the head of a hip prosthesis placed posteriorly and in a volunteer with a total knee prosthetic implant. Phantom images acquired with triband excitation were essentially identical to the composite of three single-band excitations, but with an acceleration factor of three. In vivo multiband images of the healthy knee with adjacent metal demonstrated very good depiction of knee anatomy. In vivo images of the total knee replacement were successfully acquired, allowing visualization of native tissue with far less signal dropout than 2D-FSE. FPE imaging with multiband excitation is feasible in the presence of extreme off-resonance. This approach can reduce scan time and/or increase off-resonance coverage, enabling in vivo FPE imaging near metallic prostheses over a broad off-resonance spectrum. Magn Reson Med 77:1223-1230, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Use of Ligament Advanced Reinforcement System tube in stabilization of proximal humeral endoprostheses.

To review outcomes following usage of the Ligament Advanced Reinforcement System (LARS(®)) in shoulder tumors. Medical records of nineteen patients (19 shoulders) that underwent tumor excisional procedure and reconstruction with the LARS synthetic fabric, were retrospectively reviewed. Patients' median age was 58 years old, while the median length of resection was 110 mm (range 60-210 mm). Compared to immediate post-operative radiographs, the prosthesis mean end-point position migrated superiorly at a mean follow up period of 26 mo (P = 0.002). No statistical significant correlations between the prosthesis head size (P = 0.87); the implant stem body length (P = 0.949); and the length of resection (P = 0.125) with the position of the head, were found at last follow up. Two cases of radiological dislocation were noted but only one was clinically symptomatic. A minor superficial wound dehiscence, healed without surgery, occurred. There was no evidence of aseptic loosening either, and no prosthetic failure. LARS(®) use ensured stability of the shoulder following endoprosthetic reconstruction in most patients.

Analysis of Fit of the Ascension® PyroCarbon PIP Total Joint Component Heads

The Ascension pyroCarbon proximal interphalangeal (PIP) total joint is available in 4 different sizes, and ideally, the prosthesis head will be flush with the bone. Fit of the Ascension pyrocarbon PIP joint prosthesis has not yet been investigated. The components of the Ascension pyrocarbon PIP total joint were inserted in 287 phalanges of human cadaver specimens. The distances from the edge of the component head to the edge of the bone were electronically measured radially, ulnarly, dorsally and palmarly on radiographs in posterior-anterior and lateral views. Only one finger had a precise fit of the heads of both, the proximal and corresponding distal component in relation to the bone. Only in 17 (5 proximal, 12 distal) prosthesis components the head did the bone fit on all sides. Overall, the proximal component head tends to be too large, while the distal component head tends to be too small. With occasional exceptions, the proximal and distal component heads of the Ascension pyrocarbon PIP total joint do not accomodate the dimensions of finger phalanges.

Unipolar hip prosthesis with nanocomposite ceramic coated femoral head

Hip arthroplasty in elderly patients is the most progressive method of medical treatment. The method provides rapid recovery and reha­bilitation of musculoskeletal systems at an earlier period. The aim of the present study was to analyze the structural and mechanical properties of unipolar prosthesis head surfaces made of titanium and stainless steel and coated by oxide and oxynitride nanocom­posite for hemiarthroplastic hip replacement as well as clinical approbation of prostheses «BES-T Manufacturing» (Ukraine), for possibility of applying this technology in traumatology. The struc­ture of Al2O3 (MS) and AlN/ Al2O3 (MS) magnetron sputtered films was investigated by means of XPS and XRD methods. The surface topography and roughness was estimated by profilometer Hommel T-2000 measurements and by AFM method. ElvaX spectrometer is modern analytical equipment for high-line non-destructive el­emental analysis. The analysis of the results of treatment patient’s with fractures of the femoral neck under observation period from 12 months to 3 years was presented. The unipolar hip replacement operations were made in urban trauma hospital during the period from 2012 to 2014. The age of patients was in the range from 72 to 86 years. All patients had a history of intra-articular fractures of the femoral neck. The joint femoral head surfaces with nano­composite oxide and oxinitride coatings demonstrate improved biocompatibility due to wettability increasing and fluid friction characteristics advancing. The deep understanding of the tribology of artificial joints is essential for reducing wear and corrosion of modern prostheses. Deposition of ceramic coatings on a surface of metal artificial joint’s head is an effective way to advance the functional characteristics of unipolar and bipolar prosthesis for joint arthroplasty.