This study aims to implement and assess the inter and intra-reliability of a modernised radiolucency assessment system; the Radiolucency In cemented Stemmed Knee (RISK) arthroplasty classification. Furthermore, we assessed the distribution of regions affected by radiolucency in patients undergoing stemmed cemented knee arthroplasty. Stemmed knee arthroplasty cases over 7-year period at a single institution were retrospectively identified and reviewed. The RISK classification system identifies five zones in the femur and five zones in the tibia in both the anteroposterior (AP) and lateral planes. Post-operative and follow-up radiographs were scored for radiolucency by four blinded reviewers at two distinct time points four weeks apart. Reliability was assessed using the kappa statistic. A heat map was generated to demonstrate the reported regions of radiolucency. 29 cases (63 radiographs) of stemmed knee arthroplasty were examined radiographically using the RISK system. Intra-reliability (0.83) and Inter-reliability (0.80) scores were both consistent with a strong level of agreement using the kappa scoring system. Radiolucency was more commonly associated with the tibial component (76.6%) compared to the femoral component (23.3%), and the tibial anterior-posterior (AP) region 1 (medial plateau) was the most affected (14.9%). The RISK classification system is a reliable assessment tool for evaluating radiolucency around stemmed knee arthroplasty using defined zones on both AP and lateral radiographs. Zones of radiolucency identified in this study may be relevant to implant survival and corresponded well with zones of fixation, which may help inform future research

Recently, new metallurgical techniques allowed the creation of 3D metal matrices for cementless acetabular components. Among several different products now available on the market, the Biofoam Dynasty cup (MicroPort Orthopedics® Inc., Arlington, TN, USA) uses an ultraporous Titanium technology but has never been assessed in literature. Coping with this lack of information, our study aims to assess its radiological osteointegration at two years in a primary total hip arthroplasty and compares it to a successful contemporary cementless acetabular cup. This monocentric retrospective study includes 96 Dynasty Biofoam acetabular components implanted between March 2010 and August 2014 with a minimum 2 years radiographic follow-up. Previous acetabular surgery, any septic issue or re-operation for component malposition were exclusion criteria. They were compared to 96 THA using the Trident PSL matched for age, gender, BMI and follow-up. Presence of radiolucencies and sclerotic lines were described on AP pelvis views using the classification of DeLee and Charnley. There was no statistical difference between the two groups concerning demographics and mean follow-up (p> 0.05). Shell's anteversion was similar but inclination was greater in the biofoam group (p=0.006). 27,17% of the Biofoam shells presented radiolucencies in 2 zones or more and 0% of the Trident shells. 11,96% of Biofoam cups showed radiolucencies in the 3 zones of DeLee comparing to 0% of the Trident cups. There was no statistical difference between the Biofoam group (n=54/96) and the Trident PSL group (n=57/96) in pre-operative functional scores for both WOMAC subscales and SF-12. When evaluating last follow-up PROM's, no significant differences were found comparing the entirety of both groups, 56 Biofoam and 51 Trident PSL. No difference was found either when comparing Biofoam patients with ³ 2 zones of radiolucencies (n=15) to the whole Trident group (n=51). This study raises concerns about radiologic evidence of osteointegration of the Biofoam acetabular cup. Nevertheless, these radiological findings do not find any clinical correlation considering clinical scores. Thus, it may question the real meaning of these high-rated radiolucencies, which at first sight reflect a poorer osteointegration. The first possible limitation with this study is an overinterpretation of the radiographs. Nevertheless, both observers were blinded regarding the patients groups and clinical outcomes and there was a strong inter-observer reliability. Although both cohorts were matched on their demographics and were similar on the cup anteversion, we noticed a slightly lower abduction angle in the Biofoam population. It could reduce the bone-implant coverage area and hence hinders the bony integration, but this difference was small and both groups remained in the Lewinneck security zone. Furthermore, even if patients were matched on age, gender, BMI and follow-up, other variables can influence early osteointegration (smoke status, osteoporosis) and have not been controlled even though we have no reasons to think their distribution could differ in the 2 groups. The real clinical meaning of these findings remains unknown but serious concerns are raised about the radiographic osteointegration of the Dynasty Biofoam acetabular components. Concerns are all the more lawful that this implants aim to enhance osteointegration

Objective. We aimed to analyse the clinical outcomes and survivorship of anatomic total shoulder arthroplasty using a stemless humeral component with cemented pegged polyethylene glenoid performed with the technique of eccentric reaming to partially correct retroversion. These results were then compared with TSA using the same implant for end-stage shoulder arthritis with a normal version of the native glenoid. Design and methods. A retrospective case series was performed using a prospectively collected database of anatomic TSA patients operated at Woodend General Hospital, Aberdeen, UK. Between 2010 and 2019, 107 total shoulder arthroplasties (TSA) were done using standard anatomic stemless TSA implants (Affinis Short, Mathys Ltd, Bettlach, Switzerland) in 98 patients. Standardized preoperative and postoperative shoulder radiological imaging for glenoid retroversion was collected. Depending on the angle of native glenoid version, patients were divided into retroverted and non-retroverted glenoid as per the Walch Classification. To assess the radiological outcome at the final follow-up, radiolucency was assessed on the glenoid and humeral side using the Lazarus grading. The final clinical and radiologic outcome from the retroverted group was compared with the population with a non-retroverted glenoid. Five TSAs were excluded from the analysis as they did not have satisfactory postoperative radiographs. Hence, a total of 102 shoulders were available for analysis. Results. The mean follow-up was 3.48 years (2-10.2 years) in the retroverted group (n=44) and 3.9 years (2-8.9 years) in the non-retroverted group (n=58). The mean pre-operative retroversion of the glenoid in the retroverted group was 20.18, and the post-operative retroversion was 15.87, with a mean correction of 4.31. There was no significant difference between the two groups in the percentage of radiological loosening. The mean Oxford shoulder score was 41.4 (16-48) in the retroverted group, while it was 42.1 (20-48) in the non-retroverted group. Three patients in the retroverted group required revision surgery for rotator cuff failure. There were no revisions for aseptic loosening or instability. Conclusion. The degree of severity of retroversion of the glenoid was not associated with poor clinical outcomes, revisions, or failure in stemless TSA. At medium-term follow-up, partial correction of retroversion seems to provide comparable outcomes compared to a non-retroverted glenoid

The use of cementless acetabular components is currently the gold standard for treatment in total hip arthroplasty (THA). Porous coated cups have a low modulus of elasticity that enhances press-fit and a surface that promotes osseointegration. Monoblock acetabular cups represent a subtype of uncemented cup with the liner moulded into the metal shell, minimizing potential backside wear and eliminating the chance of mal-seating. The aim of this study was to compare the short-term clinical and radiographic performances of a modular cup with that of a monoblock cup, with particular interest in the advent of lucent lines and their correlation with clinical outcomes. In this multi-surgeon, prospective, randomized, controlled trial, 86 patients undergoing unilateral THA were recruited. Participants were randomized to either a porous-coated, modular metal-on-polyethylene (MoP) acetabular component (n=46) or a hydroxyapatite (HA)- and titanium-coated monoblock shell with ceramic-on-ceramic (CoC) bearing (n=42). The porous-coated cup had an average pore size of 250 microns with an average volume porosity of 45%, whereas the monoblock shell had an average pore size of 300 microns with an average volume porosity of 48% and a HA coating thickness of 80 nm. There were no baseline demographic differences between both groups regarding sex, age, body mass index (BMI), or American Society of Anaesthesia (ASA) class (p>0.05). All of the sockets were under-reamed by 1 mm. Radiographs and patient-reported outcome measures (PROMs), including modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Arthritis Index (WOMAC) and University of California at Los Angeles (UCLA) Hip Score, were available for evaluation at a minimum of 2 years of follow-up. A radiolucent distance between the cup and acetabulum of ≥0.5 mm was defined as gap if it was diagnosed from outset or as radiolucency if it had sclerotic edges and was found on progressive x-ray analyses. Thirty-two gaps (69%) were found in the modular cup group and 28 (6%) in the monoblock one (p=0.001). Of the former, 17 filled the gaps whereas 15 turned into a radiolucency at final assessment. Of the latter, only 1 of the gaps turned into a radiolucency at final follow-up (p 0.05) in both groups. Only the porous-coated cup was an independent predictor of lucent lines (OR:0.052, p=0.007). No case underwent revision surgery due to acetabular loosening during the study period. Only 2 cases of squeaking were reported in the CoC monoblock shell. Both porous-coated modular and hydroxyapatite-coated monoblock cups showed successful clinical results at short-term follow-up, however, the former evidenced a significantly higher rate of radiolucent line occurrence, without any association with PROMs. Since these lines indicate the possibility of future cup loosening, longer follow-up and assessment are necessary

Abstract. Background. Although tantalum is a well recognised implant material used for revision arthroplasty, little is known regarding the use of the same in primary total hip arthroplasty. Methods. A literature search was performed to find all relevant clinical studies until March 2020, which then underwent a further selection criteria. The inclusion criteria was set as follows: Reporting on human patients undergoing primary total hip arthroplasty; Direct comparison between tantalum acetabular cups with conventional acetabular cups. for use in primary total hip arthroplasty; Radiological evaluation (cup migration, osteointegration); Clinical (functional scores, need for subsequent revision, patient-reported outcomes; Post-operative complications; Reporting findings in the English Language. After a thorough search a total of six studies were included in the review. The primary outcome. measures were clinical outcomes, implant migration, change in bone mineral density and rate of revision and infection. Results. Tantalum was found superior to titanium with regards to fewer radiolucencies, survivorship, osteointegration, decreased osteolysis and mechanical loosening. No significant difference in radioisometric analysis, bone mineral density or Harris Hip Score was found. Revision and infection rates were found to be significantly lower in tantalum group at 10 years from pooled data of national joint registry. Conclusion. The use of tantalum can be reserved for cases of high risk of failure or mechanical loosening, where failure of a contralateral joint occurred as it carries lower risk of failure and infection. Further studies with longer follow-up would be useful in drawing further conclusions

Introduction. Various 2D and 3D surfaces are available for cementless fixation of acetabular cups. The goal of these surface modifications is to improve fixation between the metallic cups and surrounding bone. Radiographs have historically been used to evaluate the implant-to-bone fixation around the acetabular cups. In general, a well fixed cup shows no gaps or radiolucency around the cup's outer diameter. In post-operative radiographs, the presence of progressive radiolucent zones of 2mm or more around the implant in the three radiographic zones is indicative of aseptic loosening, as described by DeLee and Charnley [1]. In this cadaveric study, we investigated the X-ray image characteristics of two different types of acetabular shell surfaces (2D and 3D) to evaluate the implant-to-bone interface in the two designs. Methods. Six human cadavers were bilaterally implanted with acetabular cups by an orthopaedic surgeon. 2D surface cups (Trident, Stryker, Mahwah, NJ) and 3D surface cups (Tritanium, Stryker, Mahwah, NJ) were randomized between the left and right acetabula. The surgeon used his regular surgical technique (1 mm under reaming) to implant the acetabular cups. The cadavers were sent for X-ray imaging after the operation, Figure 1A. Following the X-ray imaging, the acetabular cups were carefully resected from the cadavers. Enough bone around the cups was retained for analysis of the implant-to-bone interface by contact X-ray. The acetabular cups with the surrounding bone were fixed in 70% isopropyl alcohol for about a week and subsequently embedded in polymethyl methacrylate. The embedded cups were sectioned at 30° intervals using a diamond saw in the coronal plane, as recommended by Engh et al [2], Figure 1B. The sectioning of the samples produced 6 slices of each cup where the implant-bone interface could easily be visualized for evaluation with contact X-ray. Results. The AP X-rays of the cadavers demonstrated radiolucent lines, as well as gap defects in some cases. The same phenomenon was observed on the contact X-rays of the embedded implant sections as well, where one could easily identify the gap between the metal cup and the surrounding bone. The most striking finding was that, in a few cases, the contact X-rays showed radiolucency around the metal cup whereas the physical section did not seem to have any gaps. This phenomenon is illustrated in Figure 2. Conclusions. The physical gap or radiolucent lines around the acetabular cups have been reported in literature; however, they seem to fill up with time as biological fixation progresses between the surrounding bone and the implant. In our study we found radiolucency that was not associated with the presence of a physical gap. In contrast, we found gaps on physical sections that were not correlated with radiolucencies. This phenomenon may be attributed to the interaction of X-rays with the cup surface modifications. The contact X-ray images demonstrated that radiolucency around cups may not always correlate with physical gaps. Further analysis is required to understand the implications of these findings

Introduction. Cementless fixation is the current preferred method for acetabular reconstruction in total hip arthroplasty (THA). Despite promising long-term results among several designs, theoretic concerns regarding the high modulus of elasticity, low friction against bone and low volumetric porosity of contemporary cementless cups have spurred the introduction of novel porous surfaces that are designed to improve osseointegration and decrease aseptic loosening. Although several novel surfaces have been introduced into clinical use over the past decade, very little literature regarding their clinical and radiographic performance exists. The current study investigates the performance of one such novel surface, Tritanium (Stryker, Mahwah, NJ). Methods. We prospectively evaluated 121 consecutive THAs performed in 94 patients by a single arthroplasty surgeon using the Tritanium Primary Acetabular Component (Stryker, Mahwah, NJ). 109 hips (90.1%) had adequate clinical and radiological follow-up for analysis. Clinical parameters recorded included implant survivorship, Harris Hip Scores, WOMAC and SF-12. Furthermore, radiographs at the 6-week, 1 year and most recent clinical visit were evaluated by two blinded observers for implant position, evidence of radiolucency, sclerosis and component migration. Results. At an average of 3.88+1.71 years, implant survivorship was 98.1% with two hips requiring revision for aseptic loosening. Radiographs revealed that at one year postoperatively, 35.5% of hips demonstrated radiolucencies and sclerotic changes in two or more DeLee zones, with half of these (17.3%) involving all three zones. These proportions subsequently increased (37.2% and 18.4% respectively) on radiographs taken at a minimum of two years postoperatively. Hips with radiolucencies in three zones exhibited significantly lower Harris Hip Scores at two years compared to non-radiolucent hips (p=0.016). Age, gender, BMI, preoperative function and cup position did not differ between patients with and without radiolucencies. Observable bone-implant gaps on six-week radiographs were not found to be correlated with the later presence of radiolucencies. Conclusion. Despite adequate implant survivorship, we found that over one third of hips implanted with a Tritanium coated primary shell exhibit radiographic signs of fibrous ingrowth that appear to increase in prevalence over time and lead to poorer clinical function. We advocate that patients that have received this implant be followed closely for evidence of clinical deterioration and component loosening

Introduction. The first highly crosslinked and melted polyethylene acetabular component for use in total hip arthroplasty was implanted in 1998 and femoral heads larger than 32mm in diameter introduced 2004. The purpose of this study was to re-assemble a previous multi-center patient cohort in order to evaluate the radiographic and wear analysis of patients receiving this form of highly crosslinked polyethylene articulating against large diameter femoral heads at a minimum of 10 years follow-up. Methods. Two centers contributed patients to this ongoing clinical study. Inclusion criteria for patients was: primary THR; femoral heads greater than 32mm; minimum 10 year follow-up. 69 hips have been enrolled with an average follow-up of 11.2 years (10–15), 32 females (50%). Wear analysis was performed using the Martell Hip Analysis software. Radiographic grading was performed on the longest follow-up AP hip films. The extent of radiolucency in each zone greater than 0.5mm in thickness was recorded along with the presence of sclerotic lines and osteolysis. Results. Wear analysis: Using the average of the slopes of the individual regression lines, the wear rate was 0.004±0.094mm/yr. Using the early to latest film method, the wear rate was 0.035±0.076mm/yr. Radiographic analysis: Acetabular side: the greatest incidence of radiolucency occurred in zone 1 at 27%; sclerotic lines had a less than 2% incidence in any of the 3 zones; there was no identified osteolysis. Femoral side: the highest incidence of radiolucencies was in zones 1 and 3, 7% and 4%; sclerotic lines were rare in any zone, maximum in zone 3, 4%; there was no identified osteolysis. Conclusion. The wear of this form of irradiated and melted highly crosslinked polyethylene remained at levels lower than the detection limit of the software at minimum 10 year follow-up and there was no identified osteolysis

Introduction. The first highly crosslinked and melted polyethylene acetabular component for use in total hip arthroplasty was implanted in 1998. Numerous publications have reported reduced wear rates and a reduction in particle induced peri-prosthetic osteolysis at short to mid-term follow-up. The purpose of this study was to re-assemble a previous multi-center patient cohort in order to evaluate the radiographic and wear analysis of patients receiving this form of highly crosslinked polyethylene articulating against 32mm femoral heads or less at a minimum of 13 years follow-up. Methods. Inclusion criteria for patients was a primary THR with femoral heads 32mm or less and a minimum 13 year follow-up. 139 hips have been enrolled with an average follow-up of 13.7 years (13–16), 80 females (57%). Wear analysis was performed using the Martell Hip Analysis software. Radiographic grading was performed on the longest follow-up AP hip films. The extent of radiolucency in each zone greater than 0.5mm in thickness was recorded along with the presence of sclerotic lines and osteolysis. Results. Wear analysis: Using the average of the slopes of the individual regression lines, the wear rate was 0.006±0.033mm/yr. Using the early to latest film method, the wear rate was 0.003±0.056mm/yr. Radiographic analysis: Acetabular side: the greatest incidence of radiolucency occurred in zone 1 at 21%; sclerotic lines had a less than 2% incidence in any of the 3 zones; there was no identified osteolysis. Femoral side: the incidence of radiolucencies was limited to zone 1, 2%; sclerotic lines were rare in any zone, maximum in zone 3, 4%; there was no identified osteolysis. Conclusion. The wear of this form of irradiated and melted highly crosslinked polyethylene remained at levels lower than the detection limit of the software at minimum 13 year follow-up and there was no identified osteolysis

Unicompartmental Knee Replacement (UKR) is associated with fewer complications, faster recovery and better function than Total Knee Replacement (TKR). However, joint registers demonstrate a higher revision rate, which limit their use. Common reasons for revision include aseptic loosening and pain. Currently most UKRs are cemented; Cementless UKR was introduced to address these problems. In a randomised trial cementless fixation was found to have similar outcome scores but fewer radiolucencies than cemented fixation. It was also quicker and simpler. In a large multicentre cohort study in the hands of experienced surgeons it was found that following cementless UKR the incidence of complications was similar to cemented and there were no additional contra-indications. There were also no complete radiolucencies, which are common after cemented fixation. These studies demonstrate that cementless UKR are safe and effective and achieve better fixation with fewer radiolucencies than cemented UKR. They therefor suggest that cemented fixation should decrease the incidence of revision for aseptic loosening and for pain associated with radiolucency, and as a result the revision rate of UKR in the joint registers should decrease. Preliminary data from the registries demonstrates that this is happening

Twenty total hip arthroplasty were performed with use of a cementless cup in 17 patients and cemented cup in a cage in 3 patients for the treatment of posttraumatic osteoarthritis following acetabular fracture. The average age of the 4 women and 16 men was 49 (range, 26 to 86 years) at the time of the arthroplasty. The median interval between the time of injury and the total hip arthroplasty was 37 months (range, 8 to 144 months). The average operative time was 120 minutes and average intraoperative blood loss was 700 ml. Eight patients had previous open reduction and internal fixation of the acetabular fracture and twelve had been treated nonoperatively. Following total hip replacement, each patient was evaluated clinically and radiographically at six weeks, three months, six months and twelve months, and then yearly following total hip replacement. The average duration of clinical and radiographic follow-up was 40 months (range, 26 to 60 months). At the time of final follow-up, of twenty acetabular components, 10 had no evidence of periacetabular radiolucency, 7 components had a partial radiolucency that was <1 mm wide, 2 had a complete radiolucency <1 mm wide and 1 component was surrounded by a complete radiolucency of >2 mm in width without showing component migration. According to Engh's criteria, 16 (80%) femoral stems had bony ingrowth and 4 (20%) stems had stable fibrous ingrowth. The average preoperative Harris hip score improved from 35 points to 78 points at the time of final followup. Total hip arthroplasty for arthritis following acetabular fractures, technically difficult because of extensive scarring, heterotopic bone, retained internal fixation devices, and residual deformity of the acetabulum

Purpose. Short metaphyseal fitting femoral stems convey stress to proximal femur and have no distal fixation. They have advantages in that there is no thigh pain and no bone loss due to stress shielding, but there is a concern for weakened fixation. So the authors evaluated whether short metaphyseal fitting femoral stems, which have only metaphyseal and no diaphyseal fixation, can acquire sufficient stability. Materials & methods. 39 cases of 36 patients who undervent uncemented total hip arthroplasty with DePuy Proxima. TM. (Johnson & Johnson orthopaedics, New Milton, UK) short metaphyseal fitting femoral stems from August 2009 to September 2011 were retrospectively evaluated. There were 19 male and 20 female cases. The mean follow-up period was 35.8(21.8∼49.2) months. Harris hip scores, WOMAC scores, UCLA scores, and presence of femoral pain were evaluated to assess clinical outcome. Femoral radiolucency in coronal and sagittal views of the hip, femoral stem loosening, and displacement was measured to evaluate radiological outcome. Distance between femoral stem and cortical bone was also measured to assess the relationship with radiolucency and loosening according to degree of contact. Results. Harris hip score before and after operation was 49.8(37–59) and 96.0(71–100) on average. WOMAC score improved from 44.1(31.9–56.3) to 91.8(62.3–100)after operation. UCLA activity score improved from 3.8(2–5) to 7.5(4–9) after operation. When assessed with 1mm as the standard, radiolucent line was shown in 5 cases(12.8%). When the area around the stem was divided into 5 sections, there were 3 cases in which radiolucent line was observed in all 5 sections, 1 case in which radiolucent line was found in only section 4, and 1 case in which radiolucent line was found only in section 5. There was 1 case(2.6%) that required revision THA due to femoral stem loosening. Femoral radiolucency and loosening on coronal and sagittal views increased with greater distance between femoral stem and cortical bone (p=0.002). Conclusion. In uncemented total hip arthroplasty with short metaphyseal fitting femoral stem, it is important to fill the femoral metaphyseal medullary cavity completely with the femoral stem. Therefore, there is severe loss of cancellous bone at proximal femur. Stability varies with differing degree of contact between femoral stem and proximal femoral cortical bone observed on postoperative coronal and sagittal views. When short metaphyseal fitting femoral stems are used, adequate early fixation can be achieved only with understanding of such characteristics as well as sufficient proficiency of the operator

Achieving a primary outcome with revision UKR is possible but it depends on an understanding of the main failure modes and avoiding the obvious pitfalls. The most common failure mode in the long term is lateral compartment progression at 2.5% at 28 years. The most common failure overall is misdiagnosis of a painful radiolucency leading to unnecessary revision. There are a number of potential pitfalls:. Do not revise for unexplained pain. 75% of patients will go on to fail because of continuing pain. A distinction must be made to differentiate between a physiological radiolucency (with a narrow lucency accompanied by a sclerotic margin which is normal) and a pathological radiolucency (with a poorly defined lucency without surrounding sclerotic margin which is indicative of loosening and/or infection). Femoral loosening can present with subtle findings. Flexion/extension views are helpful to diagnose this problem. Wear can be a problem with fixed bearing in the second decade and can present with subtle findings. Infection can present with contralateral compartment joint space narrowing. The approach and exposure is usually straightforward and component removal is generally easy. Tibial resection is undertaken referenced from the normal lateral condyle removing 10mm of bone. Femoral preparation is generally straightforward but care must be taken to dial in correct rotation in the absence of the posterior medial condyle which was resected in the first operation. Generally a CR or PS primary implant is used with 2–4mm extra polyethylene thickness than is used in primary case. Revision for infection and stress fracture led to difficult revisions where revision components are usually required. The results for Revision UKR approach those of a primary procedure in all cases except revision for unexplained pain, infection and a stress fracture

A common location for radius fracture is the proximal radial head. With the arm in neutral position, the fracture usually happens in the anterolateral quadrant (Lacheta et al., 2019). If traditional surgeries are not enough to induce bone stabilization and vascularization, or the fracture can be defined grade III or grade IV (Mason classification), a radial head prosthesis can be the optimal compromise between bone saving and recovering the “terrible triad”. A commercially available design of radial head prosthesis such as Antea (Adler Ortho, Milan, Italy) is characterized by flexibility in selecting the best matching size for patients and induced osteointegration thanks to the Ti-Por. ®. radial stem realized by 3D printing with laser technique (Figure 1). As demonstrated, Ti-Por. ®. push-out resistance increased 45% between 8 −12 weeks after implantation, hence confirming the ideal bone-osteointegration. Additional features of Antea are: bipolarity, modularity, TiN coating, radiolucency, hypoallergenic, 10° self-aligning. The osteointegration is of paramount importance for radius, in fact the literature is unfortunately reporting several clinical cases for which the fracture of the prosthesis happened after bone-resorption. Even if related to an uncommon activity, the combination of mechanical resistance provided by the prosthesis and the stabilization due to the osteointegration should cover also accidental movements. Based upon Lacheta et al. (2019), after axial compression-load until radii failure, all native specimens survived a compression-load of 500N, while the failure happened for a mean compression force of 2560N. The aim of this research study was to test the mechanical resistance of a radial head prosthesis obtained by 3D printing. In detail, a finite element analysis (FEA) was used to understand the mechanical resistance of the core of the prosthesis and the potential bone fracture induced in the radius with simulated bone- resorption (Figure 2a). The critical level was estimated at the height for which the thickness of the core is the minimum (Figure 2b). Considered boundary conditions:. - Full-length prosthesis plus radius out of the cement block equal to 60mm (Figure 2a);. - Bone inside the cement equal to 60mm (Figure 2b);. - Load inclined 10° epiphysiary component (Figure 2c);. - Radius with physiological or osteoporotic bone conditions;. - Load (concentrated in the sphere simulating full transmission from the articulation) of 500N or 1300N or 2560N. Figure 3 shows the results in terms of maximum stress on the core of the prosthesis and the risk of fracture (Schileo et al., 2008). According to the obtained results, the radial head prosthesis shows promising mechanical resistance despite of the simulated bone-resorption for all applied loads except for 2560N. The estimated mechanical limit for the material in use is 200MPa. The risk of fracture is in agreement with the experimental findings (Lacheta et al. (2019)), in fact bone starts to fail for the minimum reported failure load, but only for osteoporotic conditions. The presented FEA aimed at investigating the behavior of a femoral head prostheses made by 3D printing with simulated bone-resorption. The prosthesis shows to be a skilled solution even during accidental loads. For any figures or tables, please contact the authors directly

Short-stem total hip arthroplasty (THA) has primarily been recommended for young and active patients, mainly due to its bone preserving philosophy. Elderly patients, however, may also benefit of a minimally invasive technique due to the short and curved implant design. The purpose of this study was to compare the clinical and radiological outcomes as well as perioperative complications of a calcar-guided short stem between a young (75 years) population. Data were collected in a total of 5 centers, and 400 short stems were included as part of a prospective multicentre observational study between 2010 and 2014 with a mean follow-up of 49.2 months. Clinical and radiological outcomes were assessed in both groups. Secondary outcomes such as perioperative complications, rates and reasons for stem revision were also investigated. No differences were found for the mean visual analogue scale (VAS) values of rest pain, load pain, and satisfaction. Harris Hip Score (HHS) was found to be slightly better in the young group. Comparing both groups, no statistically significant differences ere found in the radiological parameters that were assessed (stress-shielding, cortical hypertrophy, radiolucency, osteolysis). Aseptic loosening was the main cause of implant failure in younger patients whereas in elderly patients, postoperative periprosthetic fractures due to accidental fall was found to be the main cause for stem revision. These short-term results are encouraging towards the use of a cementless short stem in the geriatric population. According to our findings, advanced age and potentially reduced bone quality should not necessarily be considered as contra-indications for calcar-guided short-stem THA but careful and reasonable selection of the patients is mandatory. Longer follow up is necessary in order to draw safer conclusions

Unicompartmental Knee Replacement (UKR) is associated with fewer complications, faster recovery and better function than Total Knee Replacement (TKR). However, joint registries demonstrate a higher revision rate in UKR, limiting its use. Currently most UKRs are cemented and performed using a minimally invasive technique. In joint registries, common reasons for revision include aseptic loosening and pain. These problems could potentially be addressed by using cementless implants, which may provide more reliable fixation. The objectives of this study were to compare the quality of fixation (determined by the incidence and appearance of radiolucencies), and clinical outcomes of cemented and cementless UKR at five years. A randomised controlled trial was established with 63 knees (62 patients) randomised to either cemented (32 patients) or cementless UKR (30 patients). Fixation was assessed with fluoroscopic radiographs aligned to the bone-implant interface at one and five years. Outcome scores were collected pre-operatively and at one, two and five years, including Oxford Knee Score (OKS), American Knee Society Score, objective and functional (AKSS-O/F) and Tegner Activity Scale (TAS), expressed as absolute scores and 0–5 year change (δ) scores. Four patients died during the study period. There were no revisions. Mean operative time was 11 minutes shorter in the cementless group (p=0.029). At five years, there was no significant difference in any outcome measure except AKSS-F and δAKSS-F which were significantly better in the cementless group (both p=0.003). There were no femoral radiolucencies in either group. There were significantly more tibial radiolucencies in the cemented group (20/30 vs 2/27, p< 0.001). There were nine complete radiolucencies in the cemented group and none in the cementless group (p< 0.001). Cementless fixation provides improved fixation at five years compared to cemented fixation in UKR, maintaining equivalent or superior clinical outcomes with a shorter operative time and no increase in complications

Introduction. A modern total knee replacement system was introduced in 2012 in order to improve the mechanics of total knee replacement (TKR). The purpose of this study was to assess the early clinical and radiographic outcomes of patients who have been treated with this modern TKR system at two years postoperatively. Methods. Patients who received this TKR system between June of 2012 and September of 2014 were included in this prospective registry-based follow-up study. Demographics, component, and surgical data were collected. Radiographic outcomes were also assessed. Patient reported outcome measures (PROMs) of all patients with 2-year follow-up data were collected. Reasons for revision and overall survival at 2-years were evaluated. Results. The study population consisted of 290 patients (307 knees). The mean age was 66 years and 61% were women. 250 patients received cruciate retaining and 57 patients posterior stabilized implants. The median tibiofemoral axis was in 4° valgus and the femoral component was in 5° valgus and 2° flexion. The median coronal and sagittal alignment of the tibial component was −1° varus and −5° slope, respectively. Most patients had tibial components that fit the tibial resection. At one year, 7 of 80 knees had a radiolucency in the tibia or femur. At two years, two of 30 knees had a radiolucency in the tibia or femur. Mean PROMs for thirty-six patients at two years were: EQ-5D WHI 0.76 (range 0.31–1.00), EQ-5D VAS 82 (range 48–98), UCLA activity score 5.3 (range 2–10), KOOS pain 70.9 (22–100), symptoms 69 (14–96), ADL 74.2 (18–100), sports 51.4 (0–100), and QoL 59.8 (0–90). Cumulative 2-year implant survival was 97.1%. There were 7 revisions for infection and 2 revisions due to an unsatisfactory clinical outcome. Conclusion. Clinical and radiographic outcomes at two years were good, and overall implant survival was excellent

Introduction. To reduce several disadvantages many surgeons are not using tourniquet in TKA. Here we compared functional outcome along with pain and blood loss in sixty patients. Material and Method. 60 patients who underwent TKA wererandomized into a tourniquet group (n2 = 30) and a non-tourniquet group (n1 = 30). All operations were performed by the samesurgeon and follow-up was for 6 month. Primary outcomes werefunctional and clinical outcomes, as evaluated by KSS and postoperative pain. Secondary outcomes were blood loss, surgical time and visibility, extensor lag and Knee ROM, DVT and radiolucency. Result. Without significant difference in operating time, there was significant less VAS score on post operative day 0, 1 and 3(P-value=0.0,.0.01,0.03 respectively) and significantly greater number of patient were able to achieve straight leg raise on Post operative day 3 with significantly better range of motion in post operative day 3 and 5 in non-tourniquet group. Neither intraoperative blood loss nor drain nor calculated blood loss was significantly different. Functional outcome was similar in both groups on third month and sixth month. Conclusion. There was no difference in functional outcome in two groups till 6 month with no radiolucency seen till 6 month. This study shows use of tourniquet related to increase thigh and limb pain and delay in rehabilitation in early post-operative period with no difference after 5 days has better intra-operative visuality and no risk of DVT and nerve palsy

Introduction. Acetabular fixation is one of the major factors affecting long-term longevity and durability of total hip arthroplasty (THA). Limited data exist regarding mid-term performance of modern non-cemented rim-fit cups with HA coating. The aim of this study was to assess the minimum 5 year clinical and radiographic performance of PSL cups. Therefore we retrospectively analyzed results of this component in patients that had adequate followup from a prospective institutional database. Materials and Methods. A retrospective analysis of a prospective database was performed to identify patients that underwent non-cemented THA between 2003 and 2007. 223 primary THA (210 patients) were performed by single surgeon via posterolaeral approach using a grit-blasted, HA coated rim-fit design and highly cross-linked polyethylene and were followed with minimum 5 years. The mean age was 62.5 years ± 10.8. The majority of the stems were non-cemented (87%) and the majority of the femoral heads were metal (75%), 22- or 28-mm diameter. 72% of the cups were solid and 28% were multi-hole. Clinical assessment included the Hospital for Special Surgery (HSS) hip score [18] at final follow-up, and Kaplan-Meier survivorship. All patients received pre- and post-operative anteroposterior (AP) weight bearing pelvis radiograph as well as a false profile view of the hip. Cup positioning was analyzed using the EBRA software (Einzel-Bild-Roentgen-Analysis; University of Innsbruck, Innsbruck, Austria) for functional abduction angle, anteversion, and cup migration. Osseointegration was assessed on the DeLee and Charnley's zones on both AP and false profile views. Osseointegration was defined based on the following characteristics:. presence of Stress Induced Reactive Cancellous Bone (SIRCaB), where new bone condensation (not apparent on preoperative radiographs) was present at the load bearing area of the cup (Figure 1). presence of radial trabeculae that project in continuum from the shell into the pelvis, suggesting integration of the trabecular bone onto the metal surface at the load bearing area, (Figure 2). absence of radiolucency. Radiolucency was determined by radiolucent lines that were at least 1–2 mm wide and were seen in sequential radiographs, not apparent on the initial postoperative radiograph. Linear and rotational migration was defined as > 3 mm or > 5°change in the cup position, respectively, as measured on serial radiographs. Any changes in cup position or presence of circumferential radiolucencies were considered as loosening. Results. The average duration of follow-up was 6.2 ± 1.1 years (5 – 10 years). The mean HSS score was 34.8 ± 5.0 (19 – 40). There was an overall revision rate of 3.6% (8 cases) with Kaplan-Meier survivorship for all causes of 96.4% (95% CI: 0.92 – 0.98). There was one periprosthetic femur fracture. One stem was revised for fracture at the truniun/neck junction. There were 2 dislocation (0.9%); in one hip the cup was revised and the other was treated with a constrained liner. In 3 THAs (1.3%), stems were revised for loosening/failure of osseointegration (2 non-cemented stems, 0.9%) and osteolysis (one cemented stem, 0.4%). One THA (0.45%) underwent two stage revision for treatment of periprosthetic infection. There were no revisions for cup loosening or osteolysis or ceramic head fractures. The Kaplan-Meier survivorship for cup revision for any failure was 99% (95% CI: 0.96 – 0.99) and for mechanical failure was 100% (95% CI: 0.97 – 1). In radiographic analysis, the average functional cup abduction angle and anteversion were 41.7° ± 5.2 (range, 30 – 52) and 16.8° ± 6.1 (range, 4 – 30). 96% of the cups were within the safezone of Lewinnek. There were no migration or change in cup position in any cases. Presence of SIRCaB and radial trabeculae in all 3 zones were seen in 47% and 93% of cups, respectively; both were most prevalent in Zone 1. The absence of radiolucent line was observed in 96% of cases. In 161 THAs (72%), no screws were used due to excellent initial stability. Detail radiographic osseointegration assessment in the non-screw fixation group (as compared to the THAs with screw fixation) showed significantly higher incidence of SIRCaB (49% versus 39.7%, p=0.05) and radial trabeculae (97.5% versus 94.7%, p=0.001). There was also significantly less radiolucent lines in the non-screw fixation group (p=0.001). Discussion. No evidence of radiographic failure to osseointegrate was found in this study as evidenced by absence of radiolucency, evidence of radial trabeculae, and a reactive condensation of new bone to the well-fixed acetabular shell. Interestingly, we found that the solid designs had significantly better osseointegration when compared to multi-hole designs. In this single surgeon series with mid-term follow-up reiterates that the HA-coated hemispherical rim-fit acetabular component has excellent radiographic osseointegration, clinical outcomes and high survivorship for mechanical failures

Purpose. To compare and analyze the long term follow up clinical & radiological result after utilization of fixed-type & rotating-type implant for high flex both total knee replacement. Subject & Method. This paper targeted 45 patients, 90 cases that got high flex both total knee replacement with utilization of fixed-type implant(LPS-flex. ®). & rotating-type implant(P.F.C. ®. Sigma RP-F) for 1 patient by 1 operator(C.C.H) in our hospital from 2005.01 to 2006.11. Preoperative diagnoses were degenerative arthritis (43 patients, 86 cases), rheumatic arthritis (2 patients, 4 cases), mean age at the operation was 66.4 years old(54∼78), 3 men, 42 women, mean follow up period was 110.8months(97∼120). We compared and estimated Hospital for Special Surgery(HSS) score and Knee Society Score(KSS), Western Ontario and MacMaster Universities Osteoarthritis(WOMAC) score and mean range of motion of knee joint at pre-operation and last follow up for functional & clinical evaluation. And we compared and estimated change of femorotibial angle and radiolucency through erect AP & lateral x-ray at pre-, post-operation and last follow up using American Knee Society Roentgen Graphic Evaluation for radiological evaluation. Result. On the result of clinical and functional evaluation, it showed improving outcome in both group(fixed-type implant, rotating-type implant), and there was no statistically significant difference. Mean HSS score was increased from 43.0, 37.1(pre-operation) to 93.2, 92.1(last follow-up), mean KSS score was increased from 37.1, 37.2(pre-operation) to 88.8, 87.6(last follow-up), WOMAC score was also increased from 104.8, 104.4(pre-operation) to 126.1, 128.4(last follow-up). Mean joint range of motion was increased from 104.8, 104.4(pre-operation) to 126.1, 128.4(last follow-up), but there was no significant difference between 2 groups. The change of femorotibial angle was corrected from average introversion 8.2°(pre-operation) to extroversion 4.8°(post-operation) in fixed-type implant group, and average introversion 8.3°(pre-operation) to extroversion 4.8°(post-operation) in rotating-type implant group, and there was no significant difference between 2 groups. And in all cases, there was no change of radiolucency, loosening of implant, or osteolysis at the last follow-up. Conclusion. It showed good functional, clinical and radiological result on long term follow-up in both groups that got both total knee replacement with utilization of fixed-type implant and rotating-type implant for 1 patient, and there was no statistically significant difference between 2 groups. As a result, it is considered that the selection of implant will be up to the condition of patient and experience of operator and so on