Periprosthetic joint infections (PJIs) are uncommon but are devastating complications of total knee replacement (TKR). We analysed the risk factors of revision for PJI following primary TKR and their association with PJI at different post-operative periods. Primary TKRs and subsequent revision surgeries performed for PJI from 2003–2014 were identified from the National Joint Registry (NJR). Multilevel piece-wise exponential non-proportional hazards models were used to estimate the effect of the investigated factors at different post-operative periods. Patient, perioperative and healthcare system characteristics were investigated and data from the Hospital Episode Statistics for England were linked to obtain information on specific comorbidities. The index TKRs consisted of 679,010 primaries with 3,659 subsequently revised for PJI, 7% within 3 months, 6% between 3–6months, 17% between 6–12months, 27% between 1–2years and 43% ≥2 years from the index procedure. Risk factors for revision for PJI included male sex, high BMI, high ASA grade and young age. Patients with chronic pulmonary disease, diabetes and liver disease had higher risk of revision for PJI, as had patients who had a primary TKR for an indication of trauma or inflammatory arthropathy. Surgical procedure, fixation method, constraint and bearing type influenced the risk of revision for PJI. Their effects were period-specific. No or small associations were found with the operating surgeon grade, surgical volume and hospital surgical volume. These findings from the world's largest joint replacement registry show a more complex picture than the meta-analyses published to date with specific time-dependent effects for the identified risk factors.

There has not been any published work quantifying the volume cement used/needed for knee arthroplasty. The number of mixes of cement used is at the discretion of the surgeon, based on their own experience/training.

The objective of this study was to quantify the volume of cement used for knee arthroplasty in our institution, and to observe variations between surgeons and implant size. The study then aimed to calculate the theoretical volumes required and observe the volume of cement actually implanted before commenting on cost implications of cement usage.

Prospective data for 85 consecutive knee arthroplasties performed by 9 consultants was examined. A single mix in this institution refers to 40g of Palacos R+G. Significant variation between surgeons was seen, with a range of one to three mixes being used. Several surgeons used one mix exclusively, independent of implant size, whilst others exclusively used two mixes. The departmental average was 1.4 mixes per knee. The total surface area of our largest implants (Size 8 Triathlon Femoral and Tibial components) was measured-108cm² and compared to the volume of a single mix of cement −49 cm³. Even using the largest component size, a single mix will provide 4.5mm of uniform cement coverage. The volume of cement actually implanted during 10 knee arthroplasties was examined by weighing the residual cement. The average volume of cement implanted was 18cm³ per knee.

In 2009 1085 knee replacements were performed in this institution. If all surgeons in the department used a single mix of cement this could potentially save £16,357.46 per year. (Presuming average usage was 1.4 mixes per knee, 434 ‘extra’ mixes were used, costing £37.69 each) We conclude that a single mix of cement will cover the area required for all Triathlon implants and that less than half a mix (on average) is actually implanted.

Patient function is poorly characterised following revision TKA. Modern semi-constrained implants are suggested to offer high levels of function, however, data is lacking to justify this claim.

52 consecutive aseptic revision TKA procedures performed at a single centre were prospectively evaluated; all were revision of a primary implant to a Triathlon total stabiliser prosthesis. Patients were assessed pre-operatively and at 6, 26, 52 and 104 weeks post-op. Outcome assessments were the Oxford Knee Score (OKS), range of motion, pain rating scale and timed functional assessment battery. Analysis was by repeated measures ANOVA with post-hoc Tukey HSD 95% simultaneous confidence intervals as pairwise comparison. Secondary analysis compared the results of this revision cohort to previously reported primary TKA data, performed by the same surgeons, with identical outcome assessments at equivalent time points.

Mean age was 73.23 (SD 10.41) years, 57% were male. Mean time since index surgery was 9.03 (SD 5.6) years. 3 patients were lost to follow-up. All outcome parameters improved significantly over time (p <0.001). Post-hoc analysis demonstrated that all outcomes changed between pre-op, 6 week and 26 weeks post-op assessments.

No difference was seen between primary and revision cohorts in OKS (p = 0.2) or pain scores (p=0.19). Range of motion and functional performance was different between groups over the 2 year period (p=0.03), however this was due to differing pre-operative scores, post-hoc analysis showed no difference between groups at any post-operative time point.

Patients undergoing aseptic revision TKA with semi-constrained implants made substantial improvements in OKS, pain scores, knee flexion, and timed functional performance, with the outcomes achieved comparable to those of primary TKA. High levels of function can be achieved following revision knee arthroplasty, which may be important considering the changing need for, and demographics of, revision surgery.

Revision knee arthroplasty is a complex procedure with the number and cost of knee revision procedures performed per year expected to rise. Few studies have examined adverse events following revision arthroplasty. The objective of this study was to determine rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications) and to compare these with primary arthroplasty and re-revision arthroplasty. Patients undergoing primary knee arthroplasty were identified in the UK Hospital Episode Statistics. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes including infection (undergoing surgery), pulmonary embolism, myocardial infarction, stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications were included in the elective indications cohort. 939,021 primary knee arthroplasty cases were included of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% CI 0.37-0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44-0.47). Revision arthroplasty for infection, however, was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75-2.35; odds ratio [OR] 3.54; 95% CI 2.81-4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94-6.82; OR 6.23; 95% CI 4.39-8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort. These findings highlight the burden of complications associated with revision knee arthroplasty. They will inform shared decision-making for patients considering revision knee arthroplasty for elective indications. Patients presenting with infection of a knee arthroplasty or a periprosthetic fracture are at very high risk of adverse events. It is important that acute hospital services and tertiary referral centres caring for these patients are appropriately supported to ensure appropriate urgency and an anticipation for increased care requirements

The current standard of practice following knee arthroplasty is to demonstrate the appropriate alignment of knee replacements using knee radiographs. Recent studies have suggested that standard knee radiographs provide adequate accuracy for tibial prosthesis alignment assessment as compared with long knee view radiographs which are more technically demanding and carry greater radiation exposure. In this study, we aim to address whether alignment measured on standard knee radiographs are reliable and reproducible over time. We examined a cohort of 80 patients 37 male (46%), 43 females (54%), mean age = 68 years) who underwent total knee arthroplasty (TKA). Standard knee anteroposterior radiographs performed within 2 days following surgery were compared to standard knee anteroposterior radiographs taken 1 year following the surgery in patients with well-functioning prosthesis. Tibial prosthesis alignment angles between the longitude of the tibial shaft and the tibial baseplate were calculated using Centricity Enterprise Web V3.0 software. The data was examined using R software. In well-functioning primary knee arthroplasties, tibial prosthesis alignment angles measured in the 1-year follow-up standard view knee radiographs were found to deviate from measurements obtained with the same radiographic specifications in the immediate post-operative period. A significant mean percentage difference was found between the two radiographs. Long knee view radiographs may be required in order to accurately assess tibial prothesis alignment following total knee arthroplasty

In the UK and USA in 2016 more than 263,000 primary knee replacements were performed. Around 20% of patients report chronic post-surgical pain (CPSP) at three or more months after total knee replacement (TKR). A large proportion of adults with all types of chronic musculoskeletal pain do not use services for a number of reasons, despite being in constant or daily pain. Given the high prevalence of CPSP, there is potentially a large hidden population with an unexpressed need for care, experiencing ongoing pain and disability; understanding why they do not use health services may herald further insight into why many remain dissatisfied with knee replacement surgery. The aim of this study is to understand why some people with CPSP after TKR do not access services or make little use of healthcare. We conducted face-to-face in-depth interviews with 34 patients from 2 high-volume orthopaedic hospitals in England, to investigate their experience of long-term pain after knee replacement; their knowledge and understanding of CPSP; and their decisions about consulting for CPSP. The sample size was based on achievement of saturation and participants provided written informed consent. Interviews were transcribed and analysed using an inductive thematic approach with double coding for rigor. Ethical approval for the study was granted by the West Midlands Solihull Research Ethics Committee (15/WM/0469). A core theme within the analysis suggests that participants do not seek healthcare because they believe that nothing further can be done, either by themselves or by healthcare professionals. Surgeons' satisfaction with the knee surgery and reassurances that pain would improve, left patients feeling uncertain about whether to re-consult, and some assumed that further consultation could lead to further surgery or medication, which they wish to avoid. Some participants' comorbidities took precedence over their knee pain when seeking healthcare. Others felt they had received their “share” of healthcare resources and that others were more deserving of treatment. People's descriptions of pain varied, from dull, or aching to shooting pains. Many described their pain as “discomfort” rather than pain. The majority described pain that was better than their pre-surgical pain, though others described pain that was worse, which they believed to be nerve damage. Many expressed disappointment in the outcome of their TKR. Expectations of pain varied, where most had expected some post-surgical pain, others underestimated it, and some had expected to be completely pain free following their TKR. Our analysis suggests that the reasons that some people with CPSP after TKR do not consult are varied and complex, spanning psychosocial, structural, moral, and organisational domains. There was an overriding sense that further consultation would be futile or may lead to unwanted treatment. Results suggest that improved information for patients about CPSP and appropriate post-surgical healthcare services may help patients and clinicians to manage this condition more effectively

Systemic metal ion monitoring (Co;Cr) has proven to be a useful screening tool for implant performance to detect failure at an early stage in metal-on-metal hip arthroplasty. Several clinical studies have reported elevated metal ion levels after total knee arthroplasty (TKA), with fairly high levels associated with rotating hinge knees (RHK) and megaprostheses. 1. In a knee simulator study, Kretzer. 2. , demonstrated volumetric wear and corrosion of metallic surfaces. However, prospective in vivo data are scarce, resulting in a lack of knowledge of how levels evolve over time. The goal of this study was to measure serum Co and Cr levels in several types TKA patients prospectively, evaluate the evolution in time and investigate whether elevated levels could be used as an indicator for implant failure. The study was conducted at Ghent University hospital. 130 patients undergoing knee arthroplasty were included in the study, 35 patients were lost due to logistic problems. 95 patients with 124 knee prostheses had received either a TKA (primary or revision) (69 in 55 patients), a unicompartimental knee arthroplasty (7 UKA), a RHK (revision −7 in 6 patients) or a megaprosthesis (malignant bone tumours − 28 in 27 patients). The TKA, UKA and RHK groups were followed prospectively, with serum Co and Cr ions measured preoperatively, at 3,6 and 12 months postoperatively. In patients with a megaprosthesis, metal ions were measured at follow-up (cross-sectional study design). In primary knees, we did not observe an increase in serum metal ion levels at 3, 6 or 12 months. Two patients with a hip arthroplasty had elevated preTKA Co and Cr levels. There was no difference between unilateral and bilateral knee prostheses. In the revision group, elevated pre-revision levels were found in 2 failures for implant loosening. In both cases, ion levels decreased postoperatively. In revisions with a standard TKA, there was no significant increase in metal ions compared to primary knee arthroplasty. RHK were associated with a significant increase in Co levels even at short-term (3–12 months). The megaprosthesis group had the highest metal ion levels and showed a significant increase in Co and Cr with time in patients followed prospectively. With the current data, we could not demonstrate a correlation between metal ion levels, size of the implant or length of time in situ. In primary knee arthroplasty with a standard TKA or UKA, metal ion levels were not elevated till one year postoperatively. This suggests a different mechanism of metal ion release in comparison to metal-on-metal hip arthroplasties. In two cases of revision for implant loosening, pre-revision levels were elevated, possibly associated with component wear, and decreased after revision. With RHK, slightly elevated ion levels were found prospectively. Megaprostheses had significantly elevated Co and Cr levels, due to corrosion of large metallic surfaces and/or wear of components which were not perfectly aligned during difficult reconstruction after tumour resection. Further research is needed to assess the clinical relevance of metal ion levels in knee arthroplasty

Background. Surgical wound closure is not the surgeon”s favorite part of the total knee arthroplasty (TKA) surgery however it has vital rule in the success of surgery. Knee arthoplasty wounds are known to be more prone to infection, breakdown or delayed healing compared to hip arthroplasty wounds, and this might be explained by the increased tensile force applied on the wound with knee movement. This effect is magnified by the enhanced recovery protocols which aim to obtain high early range of movement. Most of the literature concluded that there is no difference between different closure methods. Objectives. We conducted an independent study comparing the complication rate associated with using barbed suture (Quill-Ethicon), Vicryl Rapide (polyglactins910-Ethicon) and skin staples for wound closure following TKA. Study Design & Methods. Retrospective study where the study group included all the patients admitted to our unit for elective primary knee arthroplasty in 2015, we excluded patients admitted for partial knee arthroplasty, revision knee arthroplasty or arthroplasty for treatment of acute trauma due to the relatively higher complication rates. All the patients notes were reviewed to identify wound related problems such as wound dehiscence, wound infection and delayed healing (defined as delayed wound healing more than 6 weeks). Results. 327 patients were included in this study; 151 in Quill group, 99 in staples group and 77 in the last group where the wound closed with Rapide. We identified 9 (5.9%) cases of wound dehiscence in the Quill group, 3 cases of wound dehiscence in each of other two groups (3.8%) with Rapide and (3%) with staples. On the other hand superficial wound infection was higher with staples with 6 (6%) cases of wound infection compared to the other groups, wound infection occurred in 2 patients (2.5%) with Rapide and 5 patients (3.3%) in the Quill”s group. Most of the delayed wound healing happened after using Quill where it is reported in 5 patients (3.3%) and the lowest was in staples group with 1 patient (1%) and slightly higher percentage in Rapide group 2 patients (2.5%). The total figure of wound related problems was the highest in Quill”s group with 19 reported cases (12.5%), lower in staples” group with 10 cases (1.1%) and the lowest in Rapide”s group with 7 cases (9%). Conclusions. Our study showed different results to the reported literature suggesting that each closure method has its own advantages and disadvantages. Quill is quick, knotless and absorbable but on the other side it is significantly more expensive than other alternatives and it is associated with the highest complication rates. On the other hand Rapide is cheap absorbable alternative with the lowest percentage of wound problems but on the negative side it is time consuming. Finally staples method is the quickest, relatively cheap and rarely associated with wound dehiscence but it is not absorbable which might cause inconvenience to patients

The number of revision knee arthroplasties performed is projected to rise dramatically in the coming years. Primary knee arthroplasties are also being performed in younger patients increasing the likelihood of multiple revision procedures. Reconstruction can be challenging with bone stock deficiencies and ligament incompetence. The aim of this study was to present our results of revision total knee arthroplasty using metaphyseal sleeve components to aid reconstruction. Sixty seven patients underwent revision total knee arthroplasty between September 2005 and November 2010 using metaphyseal sleeves. There were thirty one male and thirty six female patients. The indication for revision was aseptic loosening in thirty nine, sepsis in fifteen, malalignment in eight and instability in five patients. Thirty four patients had tibial sleeves, thirty patients had both tibial and femoral sleeves and three patients had femoral sleeves during revision. The patients were followed up for a mean of 32 months (Range 12–60) with outcome data collected prospectively. The mean revised oxford knee scores for the patients improved from 15 (Range 2 to 29) preoperatively to 33 (Range 20 to 45) postoperatively. Mean arc of flexion following revision was 87 degrees (Range 55 to 120). Seventy six percent of patients were satisfied or very satisfied with the result of the revision surgery. There have been no radiographic complications specific to the sleeves and no re-operations. There has been one recurrence of infection in a patient revised for sepsis. This has been managed with suppressive antibiotics due to patient co-morbidities. Metaphyseal sleeves are an effective adjunct in revision knee arthroplasty. We have had good results with their use. To our knowledge no larger series has been presented or published

The treatment of bony defects of the tibia at the time of revision total knee replacement is controversial. The place of compacted morsellised bone graft is becoming established, particularly in contained defects. It has previously been shown that the initial stability of impaction-grafted trays in the contained defects is equivalent to that of an uncemented primary knee replacement. However, there is little biomechanical evidence on which to base a decision in the treatment of uncontained defects. We undertook a laboratory-based biomechanical study comparing three methods of graft containment in segmental medial tibial defects and compared them with the use of a modular metal augment to bypass the defect. Using resin models of the proximal tibia with medial defects representing either 46% or 65% of the medial cortical rim, repair of the defect was accomplished using mesh, cement or a novel bag technique, after which impaction bone grafting was used to fill the contained defects and a tibial component was cemented in place. As a control, a cemented tibial component with modular metal augments was used in identical defects. All specimens were submitted to cyclical mechanical loading, during which cyclical and permanent tray displacement were determined. The results showed satisfactory stability with all the techniques except the bone bag method. Using metal augments gave the highest initial stability, but obviously lacked any potential for bone restoration

Objectives

Unicompartmental knee arthroplasty (UKA) is a demanding procedure, with tibial component subsidence or pain from high tibial strain being potential causes of revision. The optimal position in terms of load transfer has not been documented for lateral UKA. Our aim was to determine the effect of tibial component position on proximal tibial strain.

Objectives

We have increased the dose of tranexamic acid (TXA) in our enhanced total joint recovery protocol at our institution from 15 mg/kg to 30 mg/kg (maximum 2.5 g) as a single, intravenous (IV) dose. We report the clinical effect of this dosage change.

Objectives

The period of post-operative treatment before surgical wounds are completely closed remains a key window, during which one can apply new technologies that can minimise complications. One such technology is the use of negative pressure wound therapy to manage and accelerate healing of the closed incisional wound (incisional NPWT).