Displaced fractures of the neck of femur are routinely treated in the elderly by either cemented hemiarthoplasty, in the fit, or uncemented hemiarthroplasty, in the less fit. In Scotland the Scottish Intercollegiate Guidelines Network (SIGN) guidelines are followed to identify which patients should have a cemented prosthesis. This is based on cardiovascular status, and the age and fragility of the patient. An uncemented prosthesis should be a final operation. A peri-prosthetic fracture is considered a failure of treatment as the patient then has to undergo an operation with a far greater surgical insult. We looked at all neck of femur fractures over a period of Jan 2007 to June 2010. The number of the peri-prosthetic fractures for uncemented hip hemiarthroplasties was established, and a case note review was carried out. There was 1397 neck of femur fractures. 546 hemiarthroplasties were carried out, of which 183 were cemented, and 363 uncemented. 15 patients (4% of uncemented hemiarthoplasties) had peri-prosthetic fractures. There were no peri-prosthetic fractures in the cemented group, p = 0.004 using Fisher's exact test. The case notes of these patients were analysed. We found there was a common link of significant cardiovascular risk, lack of falls assessment (only 14% of the patients had a completed falls assessment and 21% sustained their fracture during an admission to hospital) and confusion (50% had a degree of dementia that caused significant confusion). Cemented implants should be considered in all patients, especially those who are cognitively impaired or have failed falls assessments; even if the cardiovascular risk is significant. This decision should be made in conjunction with a senior anaesthetist. This is being implemented in our unit and a prospective audit is being carried out over the same time period (July 2010 to Dec 2013) to assess the benefit

Displaced fractures of the neck of femur are routinely treated in the elderly by either cemented hemiarthoplasty, in the fit, or uncemented hemiarthroplasty, in the less fit. In Scotland the Scottish Intercollegiate Guidelines Network (SIGN) guidelines are followed to identify which patients should have a cemented prosthesis. This is based on cardiovascular status, and the age and fragility of the patient. An uncemeted prosthesis should be a final operation. A peri-prosthetic fracture is considered a failure of treatment as the patient then has to undergo an operation with a far greater surgical insult. We looked at all neck of femur fractures over a period of Jan 2007 to June 2010. The number of the peri-prosthetic fractures for uncemented hip hemiarthroplasties was established and a case note review carried out. There were 397 neck of femur fractures. 546 hemiarthroplasties were carried out, of which 183 were cemented, and 363 uncemented. 14 patients (4% of uncemented arthoplasties) had peri-prosthetic fractures. The case notes of these patients were analysed. There was a common link of significant cardiovascular risk, lack of falls assessment, and confusion. Cemented implants should be considered in those who have failed falls assessment, or are confused; even if the cardiovascular risk is significant. This decision should be made in conjunction with a senior anaethetist. This is being implemented in our unit and a prospective audit is being carried out over the same time period (July 2010 to Dec 2013) to assess the benefit

We present a novel use for an adult proximal humeral locking plate. In our case an 18-year-old female with cerebral palsy sustained a peri-prosthetic fracture of a blade plate previously inserted for a femoral osteotomy. Treatment was revision using a long proximal humeral locking plate. She had a successful outcome. We present the history and operative management. The female had a history of quadriplegic cerebral palsy, asthma, diabetes mellitus and congenital heart disease. She had a gastrostomy tube for enteral feeding. She was on nutritional supplements, baclofen, Omeprazole and movicol. She is looked after by her parents and requires a wheelchair for mobility. She is unable to communicate. Surgical History: Right adductor tenotomy, aged 11. Femoral Derotation Osteotomy & Dega Acetabular Osteotomy, aged 13. Right distal hamstring and knee capsule release, aged 14. Admitted to A&E (aged 18); unwitnessed fall. Painful, swollen, deformed thigh with crepitus. Xrays demonstrated peri- prosthetic fracture below blade plate. No specific equipment available to revise. Decision made to use PHILOS (Synthes, UK). GA, antibiotics, supine on table. Lateral approach. Plate removed after excising overgrown bone. Reduced and held. 10hole PHILOS applied. Near anatomical reduction. Secure fixation with locking screws proximally away from blade plate defect. Blood loss 800ml. 5 days in hospital. Sequential fracture clinic review. Wound healed well. Fracture healed on Xray at 11 months and discharged. To our knowledge this is the first reported use of a PHILOS plate for this specific fracture. The complexity of this case and underlying neurological disorder deemed long blade plate revision unsuitable. Fracture rates after femoral derotation osteotomies rare. 5/157 and 1/58 in the two largest studies to date. Conservative measures were the main recommendation. We have demonstrated a straightforward method for revision fixation with an excellent outcome. It would be recommended as an alternative to other surgeons in this position

Infection remains among the first reasons for failure of joint prosthesis. Currently, the golden standard for treating prosthetic joint infections (PJIs) is two-stage revision. However, two-stage procedures have been reported to be associated with higher costs and possible higher morbidity and mortality, compared to one-stage. Furthermore, recent studies showed the ability of a fast-resorbable, antibacterial-loaded hydrogel coating to reduce surgical site infections after joint replacement, by preventing bacterial colonization of implants. Aim of this study was then to compare the infection recurrence rate after a one-stage, cemenless exchange, performed with an antibacterial coated implant versus a standardized two-stage revision procedure.

In this two-center prospective study, 22 patients, candidate to revision surgery for PJI, were enrolled to undergo a one-stage revision surgery with cementless implants, coated intra-operatively with a fast-resorbable, antibiotic-loaded hyaluronan and poly-D,L-lactide based hydrogel coating (“Defensive Antibacterial Coating”, DAC, Novagenit, Italy). DAC was reconstructed according to manufacturer indications and loaded with Vancomycin or Vancomycin + Meropenem, according to cultural examinations, and directly spread onto the implant before insertion. This prospective cohort was compared with a retrospective series of 22 consecutive patients, matched for age, sex, host type, site of surgery, that underwent a two stage procedure, using a preformed, antibiotic-loaded spacer (Tecres, Italy) and a cementless implant. The second surgery, for definitive implant placing, was performed only after CRP normalization and no clinical sign of infection. Clinical, laboratory and radiographic evaluation were performed at 3, 6 and 12 months, and every 6 months thereafter. Infection recurrence was defined by the presence of a sinus tract communicating with the joint, or at least two among the following criteria: clinical signs of infections; elevated CRP and ESR; elevated synovial fluid WBC count; elevated synovial fluid leukocyte esterase; a positive cultural examination from synovial fluid; radiographic signs of stem loosening.

The two groups did not differ significantly for age, sex, host type and site of surgery (18 knees and 4 hips, respectively). The DAC hydrogel was loaded intra-operatively, according to cultural examination, with vancomycin (14 patients) or vancomycin and meropenem (8 cases). At a mean follow-up of 20.2 ± 6.3 months, 2 patients (9.1%) in the DAC group showed an infection recurrence, compared to 3 patients (13.6%) in the two-stage group. No adverse events associated with the use of DAC or radiographic loosening of the stem were observed at the latest follow-up months.

This is the first report on one-stage cementless revision surgery for PJI, performed with a fast-resorbable antibacterial hydrogel coating. Our data, although in a limited series of patients and at a relatively short follow-up, show similar infection recurrence rate after one-stage exchange with cementless, coated implants, compared to two-stage revision. These findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections.

There has been extensive research into neck of femur fractures in the elderly. Fragility non-hip femoral fractures share many of the same challenges [1]. Surgical management is complex, patients are frail and mortality rates have been reported as high as 38% [2]. Despite this, relatively little data is available evaluating the level of MDT care provided to non-hip femoral fractures. This audit aimed to evaluate the standard of MDT care provided for patients with non-hip femoral fractures according to the NHFD key performance indicators. The following fractures were included in the dataset: distal femoral, femoral shaft and peri-prosthetic femoral. Patients under 65 were excluded. Data was retrospectively collected using post-operative and medical documentation. Performance was assessed according to five key performance indicators:. Did orthogeriatrics review the patient within 72-hours?. Was surgery performed within 36-hours?. Was the patient weight bearing post-operatively?. Was a confusion assessment completed?. Was the patient discharged home?. 38 patients met the inclusion criteria. 84% of patients were seen by orthogeriatrics within 72 hours of admission. 32% of patients were operated on within 36-hours of admission, with time to theatre exceeding 36-hours in 92% of peri-prosthetic fractures. 37% of patients were not advised to full weight bear post operatively. 84% of patients received a confusion assessment whilst 61% of patients were discharged to their prior place of living. Our results suggest that non-hip femoral fractures do not receive the same standard of MDT care as neck of femur fractures. Greater prioritisation of resources should be given to this patient subset so that care is equivalent to hip-fracture patients. Time to surgery is a particular area for improvement, particularly in peri-prosthetic fractures, a trend that is mirrored nationally. Greater emphasis should be placed on encouraging full-weight bearing post-operatively to prevent post-surgical complications

As peri-prosthetic aseptic loosening is one of the main causes of implant failure, inhibiting wear particles induced macrophages inflammation is considered as a promising therapy for AL to expand the lifespan of implant. Here, we aim at exploring the role of p110δ, a member of class IA PI3K family, and Krüppel-like factor 4 (KLF4) in titanium particles (TiPs) induced macrophages-inflammation and osteolysis. Firstly, IC87114, the inhibitor of p110δ and siRNA targeting p110δ were applied and experiments including ELISA and immunofluorescence assay were conducted to explore the role of p110δ. Sequentially, KLF4 was predicted as the transcription factor of p110δ and the relation was confirmed by dual luciferase reporter assay. Next, assays including RT-PCR, western blotting and flow cytometry were performed to ensure the specific role of KLF4. Finally, TiPs-induced mice cranial osteolysis model was established, and micro-CT scanning and immunohistochemistry assay were performed to reveal the role of p110δ and KLF4 in vivo. Here, we found that p110δ was upregulated in TiPs-stimulated macrophages. The inhibition of p110δ or knockdown of p110δ could significantly dampen the TiPs-induced secretion of TNFα and IL-6. Further mechanistic studies confirmed that p110δ was responsible for TNFα and IL-6 trafficking out of Golgi complex without affecting their expression in TiPs-treated macrophages. Additionally, we explored the upstream regulators and confirmed that Krüppel-like factor 4 (KLF4) was the transcription repressor of p110δ. Apart from that, KLF4, targeted by miR-92a, could also attenuate TiPs-induced inflammation by mediating NF-κB pathway and M1/M2 polarization. By the establishment of TiPs-induced mice cranial osteolysis model, we found that KLF4 knockdown exacerbated TiPs-induced osteolysis which was strikingly ameliorated by knockdown of p110δ. In summary, our study suggests the key role of miR-92a/KLF4/p110δ signal in TiPs-induced macrophages inflammation and osteolysis

Cannulated hip screws are frequently used in the management of hip fractures. There have been concerns over the failure rate of the technique and the outcomes of those that subsequently require conversion to total hip replacement (THR). This study utilised a database of over 600 cannulated hip screw (CHS) fixations performed over a 14-year period and followed up for a minimum of one year (1-14). We identified 57 cases where a conversion to THR took place (40 females, 17 males, mean age: 71.2 years). Patient demographics, original mechanism of injury, fracture classification, reason for fixation failure, time until arthroplasty, implant type and post-arthroplasty complications were recorded. Clinical outcomes were measured using the Oxford Hip Score. The failure rate of cannulated screw treatment was 9.4% and the mean time from initial fixation to arthroplasty was 15.4 (16.5) months. Thirty six fractures were initially undisplaced and 21 were displaced. As one might expect the displaced cases tended to be younger but this didn't reach statistical significance [66.5(14.3) vs 72.7(13.1), p=0.1]. The commonest causes of failure were non-union (25 cases, 44%) and avascular necrosis (17 cases, 30%). Complications after THR consisted of one leg length discrepancy and one peri-prosthetic fracture. The mean Oxford score pre-arthroplasty was 12.2 (8.4), improving to 38.4 (11.1) at one-year. Although the pre op Oxford scores tended to be lower in patients with undisplaced fractures and higher ASA scores, the improvement was the same whatever the pre-op situation. The one-year Oxford score and the improvement in score are comparable to those seen in the literature for THR in general. In conclusion, CHS has a high success rate and where salvage arthroplasty is required it can provide good clinical outcomes with low complication rates

Abstract. Objective. Short-stem total hip arthroplasty (THA) aims to preserve the proximal bone stock for future revisions, so that the first revision should resemble a primary intervention rather than a revision. This study aimed to compare the clinical and radiological outcomes in revision THA after failed short stem versus after failed conventional stem THA. Methods. This study included forty-five patients with revision THA divided into three groups (15 each); group A: revision after short stem, group B: revision after conventional cementless stem and group C revision after conventional cemented stem. The studied groups were compared regarding 31 variables including demographic data, details of the primary and revision procedures, postoperative radiological subsidence, hospital stay, time for full weight bearing (FWB), preoperative and postoperative clinical scores. Results. Early stem subsidence (40%) was the main indication of revision in group A compared to peri-prosthetic femoral fractures (PFFs) (73.3%) and aseptic loosening (53.3%) in group B and C respectively (P=0.021). The mean time to revision was significantly shorter in group A (15 months) compared to 95.33 and 189.40 months in group B and C respectively. (P=0.005). Sixty % (9 patients) in group A were revised in the first year. The mean operative time, blood loss, postoperative blood transfusion and hospital stay were significantly lower in group A compared to group B and C (P<0.001, <0.001, 0.002 and 0.001 respectively). Revisions in group A were performed using either short stems (13.3%) or conventional stems (86.7%) whilst 80% of patients needed long stems and 20% of patients needed conventional stems in group B and C (P<0.001). The mean postoperative Harris Hip Score (HHS) at the latest follow up was 87.07, 87.53 and 85.47 in group A, B and C respectively. All PFFS had excellent results according to Beal's and Tower's criteria; all fractures healed and the implants were stable. Conclusion. The most common cause of failure of short stems is early stem subsidence. Short stem THA has specific indications and patient selection is very crucial. Preoperative templating for short stems and a detailed analysis of the individual patient anatomy in anteroposterior and lateral views are mandatory to predict the correct implant size more accurately. The use of intraoperative imaging can verify the sizing, implant position, and sufficient contact with the lateral cortex. Revision of short stem THA resembled the primary THA. If a standard implant can be used in a surgical revision instead of a longer revision stem, this can be considered as an advantage for the hip arthroplasty treatment concept. However, this only applies if the longevity of the first treatment with a short stem is comparable with that of a standard stem. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction and Objective. Evidence in literature is contradicting regarding outcomes of total knee arthroplasty (TKA) in post-traumatic osteoarthritis (PTOA) and whether they are inferior to TKA in primary osteoarthritis (OA). The aim of this review was to find out if any difference exists in the results of TKA between the two indications. Materials and Methods. The electronic databases MEDLINE, EMBASE, The Cochrane Collaboration, and PubMed were searched and screened in duplicate for relevant studies. The selected studies were further subjected to quality assessment using the modified Coleman method. The primary outcome measure was patient reported outcome, and secondary outcome measures were infection, revision, stiffness, and patella tendon rupture. Results. A total of 18 studies involved 1129 patients with a mean age of 60.6 years (range 45.7–69) and follow up of 6.3 years. The time interval from index injury to TKA was 9.1 years. Knee Society Score (KSS) in PTOA reported in 12/18 studies showed functional improvement from 42.5 to 70 post-TKA exceeding minimally clinically important difference. In TKA for primary OA vs PTOA, deep peri-prosthetic joint infection (PJI) was reported in 1.9% vs 5.4% of patients, whilst revision of prosthesis at an average of 6 years post-operatively was performed in 2.6 vs 9.7% of patients. Conclusions. TKA is a successful treatment option for PTOA. However, the risk of significant complications like PJI and implant failure requiring revision is higher than primary OA cases. Patients should be counselled about those risks. Further well-designed comparative cohort-matched studies are needed to compare outcomes between the two populations

Patients ≤ 55 years have a high primary TKA revision rate compared to patients >55 years. Guided motion knee devices are commonly used in younger patients yet outcomes remain unknown. In this sub-group analysis of a large multicenter study, 254 TKAs with a second-generation guided motion knee implant were performed between 2011–2017 in 202 patients ≤ 55 years at seven US and three European sites. Revision rates were compared with Australian Joint Registry (AOANJRR) 2017 data. Average age 49.7 (range 18–54); 56.4% females; average BMI 34 kg/m2; 67.1% obese; patellae resurfaced in 98.4%. Average follow-up 4.2 years; longest follow-up six years; 27.5% followed-up for ≥ five years. Of eight revisions: total revision (one), tibial plate replacements (three), tibial insert exchanges (four). One tibial plate revision re-revised to total revision. Revision indications were mechanical loosening (n=2), infection (n=3), peri-prosthetic fracture (n=1), and instability (n=2). The Kaplan-Meier revision estimate was 3.4% (95% C.I. 1.7% to 6.7%) at five years compared to AOANJRR rate of 6.9%. There was no differential risk by sex. The revision rate of the second-generation guided motion knee system is lower in younger patients compared to registry controls

Neck of femur fractures are a common presentation and certain patients can be managed with a total hip replacement. To receive a total hip replacement the pelvic X-rays should be templated as per AO guidelines and a common way this is performed is by including a calibration marker on the X-ray. The aim of this study is to assess and improve upon the use of the calibration marker. Details of patients admitted with a neck of femur fracture from January 1st 2018 until December 31st 2018 were gathered and used to review each initial X-ray and determine if a calibration marker was included. 376 patients were admitted with a neck of femur fracture over the one year period. 36% of patients did not have a calibration marker on their initial pelvic X-ray and 11% did not have a chest X ray. 215 patients had an intracapsular fracture and 39 went on to have a total hip replacement. 12 patients were lacking a calibration marker on their original X ray and required a repeat X ray. After a poster was placed in the radiographer booth acting as a visual aid, the use of a calibration marker improved from 62% to 70%. Calibration markers are useful tools which can aid the pre-operative planning for hip replacement surgeries shortening operative time, increase precision and reduce prosthetic loosening, lowers the risk of peri-prosthetic fractures, reduce leg length discrepancy and ensure the required implants are available. If a marker is not included on the initial X-rays, and a patient has a neck of femur fracture which requires a joint replacement, they may have to have additional X-rays performed as was the case for 12 patients in this study. This process leads to possible delays in surgery, additional radiation and increased healthcare costs

With increasing numbers of total joint arthroplasties being performed, peri-prosthetic fracture incidence is rising, and operative management remains the gold standard. Short-term survivorship up to 12 months has been well-documented but medium to long-term is almost unknown. We present survivorship review from a district general hospital, undertaking 800 primary hip and knee arthroplasties per year. Patients with peri-prosthetic fractures and background total knee replacements were identified using our computer database between 2006–2011. All patients were operated on our site; methods used include open reduction, internal fixation (ORIF) using Axsos (Stryker Newbury) locking plates (28), intra-medullary nailing (1) or complex revision (6) depending on fracture and patient factors and surgeon's preference. Mortality was assessed at 30 days, 12 months and 5 years. Thirty-four patients were identified with a 7:1 female to male ratio and mean age of 76. 75% of patients had their primary arthrodesis at our hospital. There was only 1 plate failure noted requiring revision plating. Mortality at 30 days, 12 months and 5 years were 3.2, 12.5% and 50% respectively. When compared to the literature our time interval from index surgery to fracture is considerably longer (115 vs 42 months). Further multi-centre reviews are required to further asses this unexpected finding. Overall mortality is better than our hip fracture cohort, suggesting that good results can be achieved in District Hospital. The longer-term results are encouraging and can act as a guide for patients with this injury. We recommend that patients are managed in consultant-led, multi-disciplinary teams

Total knee arthroplasty (TKA) is a common orthopaedic procedure with over 1,500 done in 2016 in Ireland alone. 96% of all TKAs are due to pain in the knee associated with osteoarthritis. According to the UK National Joint Registry (NJR), there is a 0.47%, 1.81%, 2.63% and 4.34% probability risk of undergoing a revision TKA within one, three, five and ten years respectively post-index surgery. A variety of reasons for failure of TKA have been described in the literature including infection, aseptic loosening, pain, instability, implant wear, mal-alignment, osteolysis, dislocation, peri-prosthetic fracture and implant fracture. The NexGen Posterior Stabilised Fixed has NJR revision rates of 0.44%, 1.61% and 2.54% at years one, three and five respectively. A retrospective review was carried out of 350 NexGen TKAs that were performed directly by, or under the supervision of, a fellowship trained arthroplasty surgeon in a dedicated orthopaedic hospital between April 2013 and December 2015. 26 (7.4%) of these were revised as of 31 December 2017. Three were for septic arthritis with the remaining 23 (6.6%) for aseptic loosening. Patients typically started to experience symptoms of medial tibial pain with supra-patellar swelling from a combination of effusion and synovial thickening at 12–24 months. Inflammatory markers were normal in all cases. Radiographs of symptomatic knee replacements showed bone loss on the medial tibia with a tilt of the tibial component into a varus alignment. The high number of revisions of this particular prosthetic has led to its use being discontinued at this centre

Femoral shaft fractures are potentially devastating injuries. Despite this, clinical studies of the biomechanics of this injury are lacking. We aimed to clinically evaluate bone behaviour under high and low energy trauma in paediatric, adult and older patients. Single-centre retrospective study identifying all diaphyseal femoral fractures between Feb 2015-Feb 2017. Peri-prosthetic and pathological fractures were excluded. Patients were subdivided into groups 1 (paediatric, <16yo), 2 (adult, 17–55yo) and 3 (older, >55yo) to reflect immature, peak bone age and osteoporotic bone respectively. Chi-Squared analysis assessed significance of bone age to degree of comminution and fracture pattern. A p-value <0.05 was significant. A total 4130 radiographs were analysed with 206 femoral shaft fractures identified. Forty-three patients were excluded with 163 remaining. Group 1, 2 and 3 included 38, 37 and 88 patients respectively. Mean age 50.8 (SD 32.8) with male-to-female ratio of 1:1.2. Groups 1 and 3 included majority simple fractures (35/38 and 62/88 respectively). Group 2 included more comminuted injuries (33/37). Bone age to degree of comminution proved significant (p<0.05) with a bimodal distribution of simple fractures noted in groups 1 and 3. Energy to fracture was significant in group 2, where a high energy injury was associated with comminution (p<0.05). This study is the first to demonstrate an association between fracture comminution and age. Simple femoral shaft fractures showed a bimodal age distribution in paediatric and older patients regardless of mechanism energy. High energy mechanism trauma was directly related to fracture comminution at peak bone age

Background. There is a paucity of long term data concerning the pre and postoperative patient reported function of total knee replacement. The aim of this study was to determine the mortality, implant survivorship, patient reported function and satisfaction in a cohort of 114 patients, from a single centre, who received a Kinemax total knee replacement more than 15 years ago. Methods. Patients completed a questionnaire incorporating validated disease- and joint-specific scores, patient satisfaction and overall health preoperatively, at 3 months, 1 year, 2 years and a minimum of 15 years following surgery. NHS National Strategic Tracing Service, hospital and primary care records were used to establish mortality and for implant survivorship in deceased patients. Results. 45 patients were alive at final follow up. The survivorship of the cohort with revision of the TKR as the endpoint was 84%. Four cases were revised for wear, three for loosening and one for peri-prosthetic fracture. There was a significant improvement in WOMAC Pain, Function and Stiffness Scores, Oxford Knee Score and Self-Administered Patient Satisfaction Scale between pre-operative and all post-operative time points, although patient satisfaction had decreased significantly by the time of final follow up. Conclusion. In this cohort, the Kinemax TKR showed satisfactory long term survivorship with functional scores demonstrating a high level of patient satisfaction at all follow up time points. Level of Evidence. 2

Total Hip Arthroplasty (THA) is a well-established, cost-effective treatment for improving function and alleviating pain in patients who have disabling hip disease with excellent long-term results. Based on the excellent results, there is an ongoing trend for THA to be performed in younger and more active patients, having higher physical demands on their new total joints. Polyethylene (PE) wear and its biological consequences are one of the main causes of implant failure in THA. Macrophages phagocytise PE wear particles and this will result in osteolysis and loss of periprosthetic bone. The risk of these complications can be estimated in relation to the amount of volumetric wear based on two assumptions: that the number of PE particles dispersed in the peri-prosthetic tissues is controlled by the amount of PE wear; and that the development of osteolysis and the resulting aseptic loosening is triggered by these PE particles. Based on these assumptions, a model was developed to estimate the osteolysis-free life of a THA, depending on the Linear Wear Rate (LWR) and femoral head size of the PE bearing. A review of the literature was conducted to provide an estimate of the radiologic osteolysis threshold based on the volumetric wear of the PE bearing. This review demonstrates that this radiologic osteolysis threshold is approximated 670 mm3 for conventional PE. The osteolysis-free life of the THA was estimated by simply dividing this threshold volume by the annual Volumetric Wear Rate (VWR) of the bearing. The annual VWR is basically controlled by two parameters: (1) annual LWR and (2) head size, and was calculated by using published formulae. For 28 mm heads, following osteolysis-free life was determined in function of the annual LWR. LWR: 10 µm/y => 116.6 years / LWR: 25 µm/y => 46.6 years / LWR: 50 µm/y => 23.3 years / LWR: 100 µm/y => 11.6 years. For 40 mm heads, following osteolysis-free life was determined in function of the annual LWR. LWR: 10 µm/y => 57.1 years / LWR: 25 µm/y => 22.9 years / LWR: 50 µm/y => 11.4 years / LWR: 100 µm/y => 5.7 years. The osteolysis-free life determined by this model is in good agreement with the clinical results of PE bearings having a 28 mm head size and demonstrates that extreme low LWRs are mandatory to assure a descent osteolysis-free life for THA (PE bearings) using large heads, such as 40 mm. For such head sizes, small variations of the LWR may have large impacts on the osteolysis-free life of the THA

Aims. Osteoporosis and abnormal bone metabolism may prove to be significant factors influencing the outcome of arthroplasty surgery, predisposing to complications of aseptic loosening and peri-prosthetic fracture. We aimed to investigate baseline bone mineral density (BMD) and bone turnover in patients about to undergo arthroplasty of the hip and knee. Methods. We prospectively measured bone mineral density of the hip and lumbar spine using dual-energy X-ray absorptiometry (DEXA) scans in a cohort of 194 patients awaiting hip or knee arthroplasty. We also assessed bone turnover using urinary deoxypyridinoline (DPD), a type I collagen crosslink, normalised to creatinine. Results. The prevalence of DEXA proven hip osteoporosis (T-score ≤ -2.5) among hip and knee arthroplasty patients was found to be low at 2.8% (4 of 143). Spinal osteoporosis prevalence was higher at 6.9% (12 of 175). Sixty patients (42% (60 of 143)) had osteopenia or osteoporosis of either the hip or spine. The mean T-score for the hip was -0.34 (. sd. 1.23), which is within normal limits, and the mean hip Z-score was positive at 0.87 (. sd. 1.17), signifying higher-than-average BMD for age. The median urinary DPD/creatinine was raised in both female patients at 8.1 (interquartile range (IQR) 6.6 to 9.9) and male patients at 6.2 (IQR 4.8 to 7.5). Conclusions. Our results indicate hip and knee arthroplasty patients have higher BMD of the hip and spine compared with an age-matched general population, and a lower prevalence of osteoporosis. However, untreated osteoporotic patients are undergoing arthroplasty, which may negatively impact their outcome. Raised DPD levels suggest abnormal bone turnover, requiring further investigation. Cite this article: Bone Joint Res 2014;3:14–19

Development of antibacterial surfaces or coatings to prevent bacterial adhesion and hence colonization of implants and biofilm formation is an attractive option, in order to reduce the tremendous impact of implant-related infections associated with modern surgery. To overcome the lack of in vivo and clinical models, able to evaluate the performance of anti-adhesive coatings, we designed an in vitro experimental setting that allows to quantitatively evaluate the ability of a coating to reduce bacterial adhesion on a given surface; this model may efficiently serve as a surrogate endpoint to validate anti-adhesive medical devices and compounds. Here we report the results the evaluation of the anti-adhesive properties of a patented, fast-resorbable hydrogel coating, (“Defensive Antibacterial Coating”, DAC). Sterile sandblasted titanium discs of approximately 5cm. 2. surface area were used as substrates for bacterial adhesion. The gel was prepared as follows: syringes prefilled with 300 mg of DAC powder (Novagenit Srl) were reconstituted with 5 ml of sterile water to obtain a hydrogel with a DAC concentration of 6%. Two experiments were conducted. In the first, 200 mg of hydrogel were homogenously spread on the surface of titanium disc, with the spreading device provided by the manufacturer. Both coated and uncoated substrates (controls) were overlaid with a standardized inoculum (10. 8. CFU/ml) of a wild methicillin-resistant Staphylococcus aureus strain, previously isolated from a peri-prosthetic joint infection, for 15, 30, 60 and 120 minutes. Afterwards, non-adherent bacteria were removed by rinsing with sterile saline. The remaining adhered cells were seeded on agar plates for CFU count. In the second experiment, the discs were first inoculated with bacterial cells followed by a treatment with the hydrogel and bacterial count as described above. Ten discs were used for each condition and each time interval (total 160 discs). The adhesion density of S. aureus on titanium discs pre-treated with DAC was significantly lower than that observed on untreated controls at each time point. In particular, the average number of adherent bacteria at 15, 30, 60 and 120 minutes of incubation, was respectively reduced by 86.8%, 80.4%, 74.6% and 66.7%, compared to controls (p<0.001). DAC treatment of discs with previously adhered S. aureus reduced bacterial adhesion, at 15, 30, 60 and 120 minutes of incubation, by, respectively, 84.0% (p<0.05), 72.8%, 72.3% and 64.3% (p<0.001), compared to untreated controls. Our results shows that DAC, “Defensive Antibacterial Coating”, has anti-adhesive properties that allow to reduce bacterial adhesion on a sanded titanium surface by more than 80%, even in the presence of remarkably high bacterial loads (10. 8. CFU/ml), of multi-resistant bacteria (MRSA) and even in the case of previous contamination. Providing anti-adhesive properties to a surface with a fast-resorbable coating may be a safe option to protect inorganic and organic surfaces and biomaterials. Those observation could be the pre-requisite for its in vivo application

Although cemented fixation provides excellent results in primary total hip replacement (THR), particularly in patients older than 75 years, uncemented implants are most commonly used nowadays. We compare the rate of complications, clinical and radiological results of three different designs over 75-years-old patients. 433 hips implanted in patients over 75 years old were identified from our Local Joint Registry. Group A consisted of 139 tapered cemented hips, group B of 140 tapered grit-blasted uncemented hips and group C of 154 tapered porous-coated uncemented hips. A 28 mm femoral head size on polyethylene was used in all cases. The mean age was greater in group A and the physical activity level according to Devane was lower in this group (p<0.001 for both variables). Primary osteoarthritis was the most frequent diagnoses in all groups. The radiological acetabular shape was similar according to Dorr, however, an osteopenic-cylindrical femur was most frequently observed in group A (p<0.001). The pre- and post-operative clinical results were evaluated according to the Merle-D'Aubigne and Postel scale. Radiological cup position was assessed, including hip rotation centre distance according to Ranawat and cup anteversion according to Widmer. We also evaluated the lever arm and height of the greater trochanter distances and the stem position. Kaplan-Meier analysis was done for revision for any cause and loosening. The hip rotation centre distance was greater and the height of the greater trochanter was lower in group B (p=0.003, p<0.001, respectively). The lever arm distance was lower in group C (p<0.001). A varus stem position was more frequently observed in group B (p<0.001). There were no intra- or post-operative fractures in group A, although there were five intra-operative fractures in the other groups plus two post-operative fractures in group B and four in group C. The rate of dislocation was similar among groups and was the most frequent cause for revision surgery (8 hips for the whole series). The mean post-operative clinical score improved in all groups. The overall survival rate for revision for any cause at 120 months was 88.4% (95% CI 78.8–98), being 97.8% (95% CI 95.2–100) for group A, 81.8% (95% CI 64.8–98.8) for group B and 95.3% (95% CI 91.1–99.6) for group C (log Rank: 0.416). Five hips were revised for loosening. The overall survival rate for loosening at 120 months was 91.9% (95% CI 81.7–100), being 99.2%(95% CI 97.6–100) for group A, 85.5 (95% CI 69.9 −100) for group B and 100% for group C (Log Rank 0.093). Despite a more osteopenic bone in the cemented group, the rate of peri-prosthetic fractures was higher after uncemented THR in patients older than 75 years. Although the overall outcome is good with both types of fixation, the post-operative reconstruction of the hip, which might be more reliable after cemented fixation, may affect the rate of complications in this population

Background. Implant stability and is an important factor for adequate bone remodelling and both are crucial in the long-term clinical survival of total hip arthroplasty (THA). Assessment of early bone remodelling on X-rays during the first 2 years post-operatively is mandatory when stepwise introduction of a new implant is performed. Regardless of fixation type (cemented or cementless), early acetabular component migration is usually the weakest link in THA, eventually leading to loosening. Over the past years, a shift towards uncemented cup designs has occurred. Besides the established hydroxyapatite (HA) coated uncemented cups which provide ongrowth of bone, new uncemented implant designs stimulating ingrowth of bone have increased in popularity. These cups initiate ingrowth of bone into the implant by their open metallic structure with peripheral pores, to obtain a mechanical interlock with the surrounding bone, thereby stabilising the prosthesis in an early stage after implantation. This retrospective study assessed bone remodelling, osseointegration and occurrence of radiolucency around a new ingrowth philosophy acetabular implant. Methods. In a retrospectively, single centre cohort study all patients whom underwent primary THA with a Tritanium acetabular component in 2011 were included. Bone remodelling, osseointegration and occurrence of radiolucency were determined by two reviewers from X-ray images that were made at 6 weeks, 3–6-12 and 24 months post-operatively. Bone contact % was calculated based on the original Charnley and DeLee zones. According to Charnley and DeLee the outer surface of an acetabular cup is divided into 3 zones (1-2-3). For our analysis the original 3 zones were further divided into 2 producing 6 zones 1A to 3B. Each of these 6 zones were then further divided into 4 equal sections. We attributed 25 points per section in which complete bone contact without lucency was observed. If lucency was observed no points were attributed to the section. A fully osteointegrated cup in all 24 sections could therefore attain 600 points. The total of each section and zone was subsequently tallied and recalculated to produce the percentage of bone contact on a 1–100% score. Results. In 2011 131 patients; 54 male and 76 female with average age of 60.83 (SD 12.42) and 60.57 (SD 12.11) year respectively underwent primary THA at our institution and all where included in our study cohort. Majority of this cohort underwent primary THA due to osteoarthrosis and most patients were classified ASO I (18%) or ASA II (65%). At two year clinical follow-up two revision were performed. One constituted a femur and acetabulum revision due to leg length difference and a snapping hip phenomenon. Complications included 3 dislocations (all treated policlinic), 4 deep infections (all treated with Genta PMMA beads with prosthesis in situ and healed) and 1 removal of hematoma. In another patient the femoral component was revised due to a peri-prosthetic fracture. Mean bone contact % values for all Charnley and DeLee zones combined were calculated and improved from 68,18% (SD 22,36) at 6 weeks to 73,61% SD (16,26) at 3 months to 84,21% (SD 19,02) at 6 months to 86,90% (SD 16,0) at 1 year to 92,19% (SD 12,74) at two year follow-up. When analysing the bone contact % per individual zone a remarkable difference was found for zones 2A-B. In contrast to zone 1A-B and 3A-B the initial bone contact % was clearly although not significantly lower until two year follow-up. Conclusions. In this study, the bone apposition around Tritanium actebular component was retrospectively assessed until two year clinical. Our results show excellent bone apposition that continues to improve over time (at least until two year clinical follow-up) suggesting that the open trabecular Ti structure of the Tritanium has a positive effect on cup osseointegration. However, some recent reports have shown the development of reactive lines around cups with porous/trabecular metal surfaces, of which the meaning is still unclear. Our analysis indicated that especially acetabular zone 2A-B according to Charnley&DeLee needs time to establish a direct contact of the implant surface and the surrounding bone tissues. Perhaps this might be explained by reaming technique (underreaming vs line to line reaming) resulting in suboptimal seating of the cup. Therefore, careful follow-up of this new implant technology will remain necessary and continued in this study. We aim to improve cohort size and establish results at longer follow-up times. Furthermore we aim to correlate these results to RSA component migration analysis