Allogenic blood is a finite resource, with associated risks. Previous studies have shown intra-operative cell salvage (ICS) can reduce allogenic transfusion rates in orthopaedic surgery. However, recent concerns regarding the efficacy and cost-effectiveness of ICS mean we must continually re-assess its usefulness in current practice. This study was carried out to review the use of ICS, to establish if its use has led to a reduction in patient exposure to post-op allogenic transfusion. All orthopaedic patients who underwent ICS and re-infusion between 2008–2010 in the Southern General Hospital (SGH) were audited. The Haemoglobin (Hb) drop, volume of blood re-infused and post-op allogenic transfusion rates were recorded. The revision hip group was compared to a similar SGH cohort, who underwent surgery by the same surgeons between 2006–2008, and a pre-2005 control group. The Cell Saver (Haemonetics) machine was used. The proportion of patients who received a post-op allogenic transfusion fell by 55% in the 2008–2010 ICS cohort compared with the control, and by 40% compared with the previous ICS study group. In both instances, this was accompanied by a statistically significant (p<0.001) reduction in mean number of units transfused per patient. ICS has been shown to be effective in reducing rates and volume of post-op allogenic transfusion in patients undergoing revision hip surgery at the SGH. ICS has been used with increasing efficiency over time

Summary Statement. Proximal femoral bony deficits present a surgical and biomechanical challenge to implant longevity in revision hip arthroplasty. This work finds comparable primary stability when a distally fixing tapered fluted stem was compared with a conical design in cadaveric tests. Introduction. Proximal bony deficits complicate revision hip surgery and compromise implant survival. Longer distally fixing stems which bypass such defects are therefore required to achieve stability compatible with bony ingrowth and implant longevity. Aims. It is hypothesised that a tapered stem will provide superior rotational stability to a conical design. This work therefore aims to compare the primary stability and biomechanical properties of a new design of tapered fluted modular femoral stem (Redapt®, Smith & Nephew) with that of a conical fluted stem (Restoration®, Stryker). Materials & Methods. 7 Pairs of cadaveric femora were obtained according to strict inclusion/exclusion criteria. Each underwent dual energy x-ray absorptiometry and calibration plain-film radiographs were taken. Digital templating was performed using TraumaCad (Voyant Health, Brainlab) to determine implant sizing. Both stems are fluted, modular and manufactured from titanium. The control stem (Restoration) featured a straight conical design and the investigation stem (Redapt) a straight tapered design. Implantation was performed by a revision arthroplasty surgeon familiar with both systems. Proximal bone deficiency was reproduced using an extended trochanteric osteotomy with removal of metaphyseal bone before reattaching the osteotomy. Primary stability in the axial, sagittal and coronal planes was assessed using micromotion transducers (HBM, Darmstadt, Germany) and also by Radiostereometric Analysis (RSA). RSA employs simultaneous biplanar radiographs to measure relative movement. Two 1mm tantalum beads were mounted on the prosthesis with the centre of the femoral head taken as the third reference point. Beads were placed proximally in the surrounding bone as rigid body markers. Each bone was potted according to the ISO standard for fatigue testing and cyclically loaded at 1Hz for at least 3 increments (750–350N, 1000–350N, 1500–350N) for 1000 cycles. RSA radiographs were taken at baseline and on completion of each cycle. A strain analysis was concurrently performed using a PhotoStress® (Vishay Precision Group, Raleigh, USA) photoelastic coating on the medial femoral cortex. Each bone was loaded intact and then with the prosthesis in-situ at 500N increments until strain fringes were identified. Once testing was completed, the stems were sectioned at the femoral isthmus and data is presented on the cross-sectional fit and fill observed. Results. Both stem designs showed comparable primary stability with all stems achieving clinically acceptable micromotion (<150 μm) when loaded at body weight. A larger proportion of the control stems remained stable as loading increased to x2-3 body weight. Transducer-recorded migration appeared greatest in the axial plane (y axis) with negligible distal movement in the coronal or sagittal planes. Point motion analysis (RSA) indicated most movement to be in the coronal plane (x-axis) whereas segment motion analysis showed rotation about the long axis of the prosthesis to be largest. Photoelastic strain patterns were transferred more distally in both designs, however substantial stress shielding was also observed. Discussion/Conclusion. Both designs achieved adequate distal fixation and primary stability under representative clinical loading conditions. This work supports the continued use of this novel stem design for revision surgery in the presence of extensive proximal bone loss

Ruling out an infection in one-stage knee and hip revisions for presumed aseptic failure by conventional tissue cultures takes up to 14 days. Multiplex polymerase chain reaction (PCR) is a quick test (4–5 hours) for detecting infections. The purpose of this study was to evaluate the negative predictive value of an automated multiplex PCR for the detection of microorganisms in synovial fluid obtained intraoperatively in unsuspected knee and hip revisions. The NPV of the multiplex PCR U-ITI system of synovial fluid compared to tissue cultures of knee and hip revisions was 95.7% and 92.5%, respectively. Cultures required several days for growth whereas the automated mPCR U-ITI system provided results within five hours. The multiplex PCR U-ITI system is a quick and reliable test in ruling out infection in presumed aseptic knee and hip revisions. With this test the number of unsuspected infected revisions can be lowered and antibiotic overtreatment as well as undertreatment after one-stage revision arthroplasty can be avoided. This directly results in a reduction in length of hospital stay, hospital costs and possible antibiotic resistance development

Revision total hip arthroplasty (THA) presents with increasing challenges, potentially compromising the integrity of a revision. The objective of this study was to assess radiologic outcomes of patients who underwent revision THA with a modular tapered stem (Reclaim, DePuy Synthes). This study retrospectively examined all revision Reclaim THAs between 2012 and 2016. Radiologic assessment compared x-rays at two time points: immediately after surgery and the most recent x-ray available. Leg length discrepancy, subsidence and line-to-line fit was assessed. Significant subsidence was considered ≥10mm. Adequate line-to-line fit was considered ≥30mm of bicortical contact. Descriptive statistics included clinical factors (i.e. age, Paprosky classification). P values <0.05 were considered significant. A total of 81 femoral revisions were completed. There were 42 females and 38 males with a mean age of 71 years (range, 46–89). Of these, 6 were revised (dislocation, fracture or infection), and 7 were lost to follow up. Average follow up time was 18 months (range, 1–46 months). Femoral revisions were classified as Paprosky 3a or 3b. Mean stem subsidence was 4.15mm (range, 0–25.6mm). Subsidence of the femoral stem was <10mm in 88% of patients. A total of 62% of patients had both subsidence <10mm and ≥30mm of bicortical contact. In patients with <10mm subsidence, 70% had ≥30mm of bicortical contact. There was a positive trend between cortical contact and stem stability (OR 2.3). The Reclaim modular femoral system has demonstrated radiographic stability. Inadequate initial fit is a potential determinant of subsidence.

The use of impaction bone grafting during revision arthroplasty of the hip in the presence of cortical defects has a high risk of post-operative fracture. Our laboratory study addressed the effect of extramedullary augmentation and length of femoral stem on the initial stability of the prosthesis and the risk of fracture.

Cortical defects in plastic femora were repaired using either surgical mesh without extramedullary augmentation, mesh with a strut graft or mesh with a plate. After bone impaction, standard or long-stem Exeter prostheses were inserted, which were tested by cyclical loading while measuring defect strain and migration of the stem.

Compared with standard stems without extramedullary augmentation, defect strains were 31% lower with longer stems, 43% lower with a plate and 50% lower with a strut graft. Combining extramedullary augmentation with a long stem showed little additional benefit (p = 0.67). The type of repair did not affect the initial stability. Our results support the use of impaction bone grafting and extramedullary augmentation of diaphyseal defects after mesh containment.

Prosthetic joint infection (PJI) is an uncommon but serious complication of hip and knee replacement. We investigated the rates of revision surgery for the treatment of PJI following primary and revision hip and knee replacement, explored time trends, and estimated the overall surgical burden created by PJI. We analysed the National Joint Registry for England and Wales for revision hip and knee replacements performed for a diagnosis of PJI and their index procedures from 2003–2014. The index hip replacements consisted of 623,253 primary and 63,222 aseptic revision hip replacements with 7,642 revisions subsequently performed for PJI; for knee replacements the figures were 679,010 primary and 33,920 aseptic revision knee replacements with 8,031 revisions subsequently performed for PJI. Cumulative incidence functions, prevalence rates and the burden of PJI in terms of total procedures performed as a result of PJI were calculated. Revision rates for PJI equated to 43 out of every 10,000 primary hip replacements (2,705/623,253), i.e. 0.43%(95%CI 0.42–0.45), subsequently being revised due to PJI. Around 158 out of every 10,000 aseptic revision hip replacements performed were subsequently revised for PJI (997/63,222), i.e. 1.58%(1.48–1.67). For knees, the respective rates were 0.54%(0.52–0.56) for primary replacements, i.e. 54 out of every 10,000 primary replacements performed (3,659/679,010) and 2.11%(1.96–2.23) for aseptic revision replacements, i.e. 211 out of every 10,000 aseptic revision replacements performed (717/33,920). Between 2005 and 2013, the risk of revision for PJI in the 3 months following primary hip replacement rose by 2.29 fold (1.28–4.08) and after aseptic revision by 3.00 fold (1.06–8.51); for knees, it rose by 2.46 fold (1.15–5.25) after primary replacement and 7.47 fold (1.00–56.12) after aseptic revision. The rates of revision for PJI performed at any time beyond 3 months from the index surgery remained stable or decreased over time. From a patient perspective, after accounting for the competing risk of revision for an aseptic indication and death, the 10-year cumulative incidence of revision hip replacement for PJI was 0.62%(95%CI 0.59–0.65) following primary and 2.25%(2.08–2.43) following aseptic revision; for knees, the figures were 0.75%(0.72–0.78) following primary replacement and 3.13%(2.81–3.49) following aseptic revision. At a health service level, the absolute number of procedures performed as a consequence of hip PJI increased from 387 in 2005 to 1,013 in 2014, i.e. a relative increase of 2.6 fold. While 70% of those revisions were two-stage, the use of single stage revision increased from 17.6% in 2005 to 38.5% in 2014. For knees, the burden of PJI increased by 2.8 fold between 2005 and 2014. Overall, 74% of revisions were two-stage with an increase in use of single stage from 10.0% in 2005 to 29.0% in 2014. Although the risk of revision due to PJI following hip or knee replacement is low, it is rising. Given the burden and costs associated with performing revision joint replacement for prosthetic joint infection and the predicted increased incidence of both primary and revision hip replacement, this has substantial implications for service delivery

Background

Frequency of primary total hip (THA) and total knee (TKA) arthroplasty procedures is increasing, with a subsequent rise in revision procedures. This study aims to describe timing and excess surgical mortality associated with revision THA and TKA compared to those on the waiting list.

250 words max Long polished cemented femoral stems, such as the Exeter Hip Revision stem, are one option available to the revision hip arthroplasty surgeon. When proximal bone stock is compromised, distal fixation is often relied upon for stability of the femoral component. In such circumstances, torsional forces can result in debonding and loosening. This study compared the torsional behaviour of a cemented polished and featureless (plain) stem with cemented, polished stems featuring fins or flutes. Nine torsional tests were carried out on each of these three different stem designs. The finned stem construct was significantly stiffer than the fluted stem (mean 24.5 Nm/deg v 17.5 Nm/deg). The plain stem mean stiffness was less than the featured stems (13 Nm/deg), but wide variability lead to no statistically significant difference. The maximum torque of the finned (30.5 Nm) and fluted stems (29 Nm) was significantly higher than the plain stem (10.5 Nm); with no significance to the difference between the finned and fluted stems. Distal stem features may provide a more reliable and greater resistance to torque in polished, cemented revision hip stems. Finned stem features may also increase the stiffness of the construct. Consideration should thus be given to the incorporation of distal stem features in the design of revision hip stems

Background. Over 96% of primary total hip replacements (THR) recorded in the National Joint Registry (NJR) are performed through a posterior or lateral surgical approach. There is no high quality evidence available to support the use of one approach over the other in primary THR and even less evidence when the outcome of revision THR is considered. Methods. Questionnaires were sent to 267 patients who had revision hip replacements between January 2006 and March 2010 for aseptic loosening. They rated their pain from 0–10, and used the Self-Administered Patient Satisfaction Scale (SAPS), Oxford Hip Score (OHS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Short form-12 (SF-12). Results. We performed 275 revision total hip replacements for aseptic loosening on patients in whom the primary operation details were available. Their mean age was 69 years (SD12) with 43% male and 57% right-sided procedures. 205 patients responded to our questionnaires (209/275 hips, 76%). Unfortunately 19 patients had died, 4 had dementia and 13 declined to participate. We were unable to contact a further 33.Grouping by approach, 20% (43/209) had primary and revision lateral approaches, 20% (43/209) had primary lateral and revision posterior and 60% (123/209) had both primary and revision via posterior approaches. The WOMAC and OHS were significantly better in patients who had a posterior approach for both primary and revision surgery, compared to those that did not (OHS p=0.028, WOMAC p=0.026). We found no significant differences in pain, satisfaction or health-related quality of life between the groups. Conclusions. Registry data may help further explore the relationship between surgical approach and outcome in revision hip surgery. A randomised controlled trial of the posterior versus lateral approach for revision surgery would provide a definitive answer. Level of Evidence. 2b - retrospective cohort study. Disclosures. No financial disclosures or conflicts of interests from any authors

Improvements in arthroplasty design and materials led to superior lifetime of the implants. Nevertheless, aseptic loosening due to particulate debris is still one of the most frequent late reasons for revision of hip and knee replacements. The complex process of inflammation and osteolysis due to wear particles is not understood in detail so far. A cellular and receptor mediated response to wear particles results in a release of pro-inflammatory cytokines and induces an inflammatory reaction causing periprosthetic osteolysis. The overall cellular response is influenced by particle volume as well as characteristics. But there is still a lack of data concerning all signalling pathways that are involved. To answer some open questions appropriate in vivo models are shown closing the loop between wear simulation, particle analysis, generation of sterile particles and biological evaluation. Beyond that, new aspects of particle effects and deposits in retrieved human tissue are given

This study investigates the use of porous biphasic ceramics as graft extenders in impaction grafting of the femur during revision hip surgery. Impaction grafting of the femur was performed in four groups of sheep. Group one received pure allograft, group two 50% allograft and 50% BoneSave, group three 50% allograft and 50% BoneSave type 2 and group four 10% allograft and 90% BoneSave as the graft material. Function was assessed using an index of pre- and post-operative peak vertical ground reaction force ratios. Changes in bone mineral density were measured by dual energy X ray absorptiometry (DEXA) scanning. Loosening and subsidence were assessed radiographically and by histological examination of the explanted specimens. There was no statistically significant difference between the four groups after 18 months of unrestricted functional loading for all outcome measures

Objectives. The objective of this study was to develop a test for the rapid (within 25 minutes) intraoperative detection of bacteria from synovial fluid to diagnose periprosthetic joint infection (PJI). Methods. The 16s rDNA test combines a polymerase chain reaction (PCR) for amplification of 16s rDNA with a lateral flow immunoassay in one fully automated system. The synovial fluid of 77 patients undergoing joint aspiration or primary or revision total hip or knee surgery was prospectively collected. The cohort was divided into a proof-of-principle cohort (n = 17) and a validation cohort (n = 60). Using the proof-of-principle cohort, an optimal cut-off for the discrimination between PJI and non-PJI samples was determined. PJI was defined as detection of the same bacterial species in a minimum of two microbiological samples, positive histology, and presence of a sinus tract or intra-articular pus. Results. The 16s rDNA test proved to be very robust and was able to provide a result in 97% of all samples within 25 minutes. The 16s rDNA test was able to diagnose PJI with a sensitivity of 87.5% and 82%, and a specificity of 100% and 89%, in the proof-of-principle and validation cohorts, respectively. The microbiological culture of synovial fluid achieved a sensitivity of 80% and a specificity of 93% in the validation cohort. Conclusion. The 16s rDNA test offers reliable intraoperative detection of all bacterial species within 25 minutes with a sensitivity and specificity comparable with those of conventional microbiological culture of synovial fluid for the detection of PJI. The 16s rDNA test performance is independent of possible blood contamination, culture time and bacterial species. Cite this article: V. Janz, J. Schoon, C. Morgenstern, B. Preininger, S. Reinke, G. Duda, A. Breitbach, C. F. Perka, S. Geissler. Rapid detection of periprosthetic joint infection using a combination of 16s rDNA polymerase chain reaction and lateral flow immunoassay: A Pilot Study. Bone Joint Res 2018;7:12–19. DOI: 10.1302/2046-3758.71.BJR-2017-0103.R2

Impaction bone grafting with milled human allograft is the gold standard for replacing lost bone stock during revision hip surgery. Problems surrounding the use of allograft include cost, availability, disease transmission and stem subsidence (usually due to shear failure of the surrounding allograft). The aim of this study was to investigate various polymers for use as substitute allograft. The ideal graft would be a composite with similar mechanical characteristics as allograft, and with the ability to form de novo bone. High and low molecular weight (MW) forms of three different polymers (polylactic acid (PLA), poly (lactic co-glycolic) acid (PLGA) and polycaprolactone (PCL)) were milled, impacted into discs, and then tested in a custom built shear testing rig, and compared to allograft. A second stage of the experiment involved the addition of skeletal stem cells (SSC) to each of the milled polymers, impaction, 8 days incubation, and then tests for cell viability and number, via fluorostaining and biochemical (WST-1) assays. The shear strengths of both high/ low MW PLA, and high/low MW PLGA were significantly higher than those of milled allograft (P<0.001, P<0.001, P<0.005 and P<0.005) but high and low MW PCL was poor to impact, and had significantly lower shear strengths (P<0.005, P<0.001). Fluorostaining showed good cell survival on high MW PLA, high MW PCL and high MW PLGA. These findings were confirmed with WST-1 assays. High MW PLA as well as high MW PLGA performed well both in mechanical testing and cell compatibility studies. These two polymers are good contenders to produce a living composite for use as substitute human allograft in impaction bone grafting, and are currently being optimised for this use via the investigation of different production techniques and in-vivo studies

We performed 83 consecutive cemented revision total hip arthroplasties in 77 patients between 1977 and 1983 using improved cementing techniques. One patient (two hips) was lost to follow-up. The remaining 76 patients (81 hips) had an average age at revision of 63.7 years (23 to 89). At the final follow-up 18 hips (22%) had had a reoperation, two (2.5%) for sepsis, three (4%) for dislocation and 13 (16%) for aseptic loosening. The incidence of rerevision for aseptic femoral loosening was 5.4% and for aseptic acetabular loosening 16%. These results confirm that cemented femoral revision is a durable option in revision hip surgery when improved cementing techniques are used, but that cemented acetabular revision is unsatisfactory

The Trident acetabular system is the second most common cementless cup implanted in the UK. Recent studies have shown that malseating of the liner can be as high as 16.4%. We felt this was very high and were prompted to review our series and early clinical outcomes. We reviewed 118 hips in 110 patients, implanted between from 2005-2007. We reviewed initial post operative X-rays using the technique described by Howcroft to identify malseating. The posterior approach was used in all cases. All cups were Trident PSL and all 85 Patients had OA, 10 RA, 8 AVN, 5 DDH, 3 OA post trauma, 2 Perthes, 2 Psoriatic Arthritis, 3 other. We only identified 3 malseated cups in 118 hips. 2 were in patients with OA secondary to trauma and 1 in primary OA. The rate of malseating for trainees operating was 5 % and only 1% when consultants were operating. There were no adverse events in these patients. No-one required revision. Oxford Hip Score (OHS) improved from 47 pre-op to 20 post op. This was compared to 47 and 22 in the correctly seated group (115 cases). Surprisingly the subgroup with the poorest OHS at 1 year had surgery for DDH, with a mean OHS of 31. The reasons for this are unclear. Contrary to other studies our malseating rate is very low. We do not feel that malseating is a problem with Trident if adequate exposure is obtained. In those patients with sclerotic bone, we suggest over reaming the rim of the acetabulum by 1mm to avoid excess deformation of the shell which may lead to difficulty with seating the liner. We suggest trainees are supervised closely when using Trident

The role of bone-graft extenders in impaction revision surgery is becoming increasingly important. Tricalcium phosphate and hydroxyapatite have been shown to be both biocompatible and osteoconductive, yet many surgeons remain reluctant to use them. The difficulty in handling bone-graft extenders can be partly alleviated by using porous particles and adding clotted blood.

In an in vitro model we measured the cohesive properties of various impaction graft mixes. Several factors were evaluated including the use of pure bone graft compared with mixes with extender, washing the bone and the addition of clotted blood.

Our findings showed that pure allograft bone particles had significantly higher cohesion than when mixed with extender (p < 0.001). Washing had no effect on cohesion. The addition of clotted blood significantly increased the cohesion of both pure bone (p < 0.019) and mixes with pure bone and with porous graft extender (p < 0.044).