Management of septic arthritis and prosthetic joint infection.

Management of joint infection is an evolving topic. This article reviews the literature on the management of native and prosthetic joint infection and suggests some areas of improvement in short- and long-term management which could lead to better patient outcomes. Surgical management is the mainstay of treatment for native or prosthetic knee infection and aspiration should only be used for diagnostic purposes. A multidisciplinary team approach and compliance with national guidelines, alongside referral networks and pooling of expertise, should be mandatory to improve patient outcomes.

Permanent Resection Arthroplasty of the Knee as Limb Salvage Following Recurrent Periprosthetic Infection Complicated with Osteomyelitis.

Introduction: Permanent resection or excision arthroplasty of the knee involves the removal of any infected prosthetic material and thorough debridement, with no further reimplantation. The more common alternatives to permanent resection arthroplasty include knee arthrodesis or above-knee amputation (AKA). Case Report: We describe two cases of complex periprosthetic infections of the knee associated with subsequent osteomyelitis, which were unsuitable for re-revision arthroplasty. Both patients chose to remain with an excision arthroplasty, rather than undergo arthrodesis or AKA, respectively, and were satisfied with their quality of life at long-term follow-up. Conclusion: Although permanent resection arthroplasty of the knee is rarely performed, it remains a limb salvage option in certain cases where bone loss is limited, functional demands are low, and further surgery may present a significant risk.

A cross-sectional evaluation of the current state of wound healing education in the United Kingdom's undergraduate medical curriculum.

Between 2013 and 2018, there has been a 71% increase in the number of patients who have required wound care in the NHS and such large numbers has placed a significant burden on healthcare systems. However, there is currently no evidence as to whether medical students are equipped with the necessary skills to deal with an increasing number of wound care related issues that patients present with. A total of 323 medical students across 18 UK medical schools completed an anonymous questionnaire evaluating the wound education received at their medical school, encompassing the volume, content, format and efficacy of teaching. 68.4% (221/323) of respondents had received some form of wound education during their undergraduate studies. On average students received 2.25 h of structured, preclinical teaching and only 1 h of clinical based teaching in total. All students that received wound education reported undertaking teaching on the physiology of, and factors affecting wound healing, with only 32.2% (n = 104) of students receiving clinically based wound education There was very weak correlation and no significant association in student's ability to assess wounds (R2 = 0.190, p = 0.013), manage wounds (R2 = 0.060, p = 0.37), and prescribe wound care products (R2 = 0.093, p = 0.18) with their stage of training. Students strongly agreed that wound education is an important part of the undergraduate curriculum and post graduate practice, and do not feel their learning needs have been met. This is the first study to assess the provision of wound education in the United Kingdom, demonstrating a clear deficit in the provision of wound education compared to expectation of junior doctors. Wound education is largely overlooked in the medical curriculum, lacks a clinical focus and does not prepare junior doctors with the necessary clinical abilities to deal with wound related pathology. Expert opinion to direct changes to future curriculum and further evaluation of teaching methodology is required to address this deficit and ensure students have the necessary clinical skills to excel as newly graduated doctors.

Results of revision knee replacement for patients with isolated fixed flexion deformity after primary or revision knee replacement.

BACKGROUND: Postoperative fixed flexion deformity is a known complication of knee replacement surgery. We present our results of revision surgery for treatment of isolated fixed flexion deformity after knee replacement. METHODS: 32 patients had revision knee replacement for fixed flexion deformity and were included in this retrospective study. Minimum follow up period was 28 months. RESULTS: Two different surgical interventions had been done in these patients. Group 1 (15 patients) had revision of the femoral component, posterior capsular release and tibial component was not revised. Group 2 (18 Patients) had revision of both femoral and tibial components. One patient was included in both groups as she had both interventions. The extent of preoperative flexion deformity in group 1 was from 15 to 40 deg (mean 20.6 deg). Postoperative range of extension was 0 to 20 deg (mean 8.2 deg). In group 2, preoperative flexion deformity was 10 to 25 deg (mean 16.9 deg) and postoperative flexion deformity was 0 to 20 deg (mean 4.2 deg). The difference in improvement between the two groups was not statistically significant on Mann Whitney U test (two tailed p value 0.181) for non normal distribution. Improvement in Oxford knee score following surgery was only 1 point in both groups. CONCLUSION: Revision for isolated fixed flexion deformity leads to improvement in range of extension, but improvement in clinical score is marginal. The choice of preservation or revision of the tibial component did not make a significant difference to the outcome.

Metaphyseal Sleeve Failure in Revision Total Knee Arthroplasty.

Introduction A significant percentage of patients require re-revision surgery regardless of the demonstrated durable short- and mid-term clinical results using metaphyseal sleeves in revision total knee arthroplasty (TKA). The aim of this study was to identify the association between sleeve alignment and contact zones, with loosening in patients with revision TKA. Materials & Methods Of a series of 103 patients who underwent revision TKA, at a mean follow-up of eight years, six patients were re-revised for tibial loosening. These patients were compared with 19 unrevised control subjects in a 1:3 ratio. We calculated and compared the cumulative number of contact zones between the porous-coated part of the sleeve and bone on immediate postoperative X-rays between re-revised and unrevised patients. The main hypothesis was that neutral positioning and absolute circumferential contact between trabecular metaphyseal bone and porous-coated part of the sleeve would lead to a better outcome. Results The use of a conservative (nonparametric) approach indeed revealed better circumferential contact between trabecular metaphyseal bone and porous-coated part of the sleeve among the survivors, i.e., survivors: median (interquartile range [IQR]): 3 (2-4); failures: 3 (1-3), p = 0.003 (Mann-Whitney [MW] test). The difference was borderline significant for coronal alignment, i.e., survivors: median (IQR): -1 (-4 to 2); failures: 0 (-1 to 3), p = 0.0569 (MW test). Conclusion A circumferential bony contact of the metaphyseal sleeve would lead to better survival of the revision implant, whereas the degree of varus fixation did not seem to influence the longevity of the implant.

Single-stage revision for the infected total knee arthroplasty : the Cardiff experience.

AIMS: Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA). Two-stage revision has traditionally been considered the gold standard of treatment for established infection, but increasing evidence is emerging in support of one-stage exchange for selected patients. The objective of this study was to determine the outcomes of single-stage revision TKA for PJI, with mid-term follow-up. METHODS: A total of 84 patients, with a mean age of 68 years (36 to 92), underwent single-stage revision TKA for confirmed PJI at a single institution between 2006 and 2016. In all, 37 patients (44%) were treated for an infected primary TKA, while the majority presented with infected revisions: 31 had undergone one previous revision (36.9%) and 16 had multiple prior revisions (19.1%). Contraindications to single-stage exchange included systemic sepsis, extensive bone or soft-tissue loss, extensor mechanism failure, or if primary wound closure was unlikely to be achievable. Patients were not excluded for culture-negative PJI or the presence of a sinus. RESULTS: Overall, 76 patients (90.5%) were infection-free at a mean follow-up of seven years, with eight reinfections (9.5%). Culture-negative PJI was not associated with a higher reinfection rate (p = 0.343). However, there was a significantly higher rate of recurrence in patients with polymicrobial infections (p = 0.003). The mean Oxford Knee Score (OKS) improved from 18.7 (SD 8.7) preoperatively to 33.8 (SD 9.7) at six months postoperatively (p < 0.001). The Kaplan-Meier implant survival rate for all causes of reoperation, including reinfection and aseptic failure, was 95.2% at one year (95% confidence interval (CI) 87.7 to 98.2), 83.5% at five years (95% CI 73.2 to 90.3), and 78.9% at 12 years (95% CI 66.8 to 87.2). CONCLUSION: One-stage exchange, using a strict debridement protocol and multidisciplinary input, is an effective treatment option for the infected TKA. This is the largest single-surgeon series of consecutive cases reported to date, with broad inclusion criteria. Cite this article: Bone Jt Open 2021;2(5):305-313.

Balance and constraint in revision TKR: A classification for instability management.

Instability is an increasingly common cause and symptom of failure of Total Knee Arthroplasty (TKA). Patients seek 'Functional Stability', which is the sum of both a balanced joint and, if necessary, mechanical constraint. The objective of this paper is to classify the different types of TKA instability and their causes. Based on this classification, the authors give methodical recommendations for instability management. INSTABILITY CLASSIFICATION: Instability in revision TKA can be classified into 3 types based on the management of bone loss and ligamentous deficiency which directs the level of constraint required to achieve functional stability. TYPE 1: Bone deficiency: Revision with restoration of joint line and rebuilding the bony anatomy results in a balanced joint. No increased constraint is needed. TYPE 2: Ligament and soft tissue deficiency: Requires increased constraint to overcome instability. TYPE 3: Composite (Total) deficiency: (combined Type 1 and 2).The multiple causes of instability are outlined for each Instability type along with an algorithm for restoring the joint line and adding titrated constraint to restore functional stability.

Alternative radiopacifiers for polymethyl methacrylate bone cements: Silane-treated anatase titanium dioxide and yttria-stabilised zirconium dioxide.

Poly (methyl methacrylate) (PMMA) bone cement is widely used for anchoring joint arthroplasties. In cement brands approved for these procedures, micron-sized particles (usually barium sulphate, BaSO4) act as the radiopacifier. It has been postulated that these particles act as sites for crack initiation and subsequently cement fatigue. This study investigated whether alternative radiopacifiers, anatase titanium dioxide (TiO2) and yttria-stabilised zirconium dioxide (ZrO2), could improve the in vitro mechanical, fatigue crack propagation and biological properties of polymethyl methacrylate (PMMA) bone cement and whether their coating with a silane could further enhance cement performance. Cement samples containing 0, 5, 10, 15, 20 and 25%w/w TiO2 or ZrO2 and 10%w/w silane-treated TiO2 or ZrO2 were prepared and characterised in vitro in terms of radiopacity, compressive and bending strength, bending modulus, fatigue crack propagation, hydroxyapatite forming ability and MC3T3-E1 cell attachment and viability. Cement samples with greater than 10%w/w TiO2 and ZrO2 had a similar radiopacity to the control 10%w/w BaSO4 cement and commercial products. The addition of TiO2 and ZrO2 to bone cement reduced the bending strength and fracture toughness and increased fatigue crack propagation due to the formation of agglomerations and voids. Silane treating TiO2 reversed this effect, enhancing the dispersion and adhesion of particles to the PMMA matrix and resulted in improved mechanical properties and fatigue crack propagation resistance. Silane-treated TiO2 cements had increased nucleation of hydroxyapatite and MC3T3-E1 cell attachment in vitro, without significantly compromising cell viability. This research has demonstrated that 10%w/w silane-treated anatase TiO2 is a promising alternative radiopacifier for PMMA bone cement offering additional benefits over conventional BaSO4 radiopacifiers.

Revision Total Knee Arthroplasty Using an Uncemented Metaphyseal Sleeve, Rotating Hinge Prosthesis: A Case Series of 99 Patients.

BACKGROUND: Hinge knee replacement is a salvage procedure with historically high failure and complication rates. We aim to analyze the use of an uncemented metaphyseal sleeve revision knee replacement in our unit-a third-generation rotating hinge knee prosthesis. This is the largest reported series of this implant with longest follow up. METHODS: We retrospectively identified 99 revision cases performed (2002-2018). In total, 67 of 99 (68%) cases were performed for aseptic etiology, whereas 32 of 99 (32%) cases were performed for infection. Clinical outcomes were assessed using the Oxford Knee Score, survivorship analysis, and incidence of revision/reoperations. Mean follow-up was 7 years (range 1.5-18). RESULTS: At follow-up, the mean Oxford Knee Score had improved from 10 points to 25 points. At mean 7 years of follow up, 18 of 99 cases had undergone revision giving a survivorship of 81% (90% aseptic). In total, 10 of 18 cases were performed for infection (10%) and 9 of 18 cases were performed for aseptic reasons (9%), of which 5 were for patella resurfacing (2 revision), 2 for failure of bony ingrowth, and 1 for fracture. Twenty-six patients (26%) had complications postoperatively, with patella disorders and reduced range of movement the most common. Patients who did not undergo patella resurfacing were significantly more likely to need revision of any cause (P = .01). CONCLUSION: This is the largest study of this prosthesis with longest follow-up. It demonstrates good survivorship and improvement in knee pain. Those with infection are at greatest risk of revision. Significant numbers have patella dysfunction/anterior knee symptoms therefore patella resurfacing should be considered when using this implant. LEVEL OF EVIDENCE: IV.

Infected total knee replacement: How I do a one-stage revision.

BACKGROUND: As part of a session on the infected knee replacement at the British Orthopaedic Association congress in Liverpool, 2019, this topic was delivered as a lecture. The content and ideas of the lecture have been expanded to produce this article. METHODS: One-stage revision total knee replacement is not a new concept but remains controversial. This article is not written to persuade any surgeon to undertake the procedure but to simply give a working framework for how one surgeon performs the operation. We will cover the philosophy underpinning the rationale for single-stage revision (not 2-in-1 revision) including extensile exposure, a defined debridement protocol, reconstruction and fixation, antibiotic delivery and exclusion criteria. RESULTS: None. CONCLUSION: The techniques outlined in this article should give confidence that one-stage revision knee replacement is a viable option when working within a multi-disciplinary team structure.

The 'apple core' cement spacer for the management of massive bone loss in two-stage revision knee arthroplasty for infection.

Antibiotic-loaded cement spacers are used in two-stage revision knee arthroplasty for infection, but commercially available spacers may not always be suitable for significant bone loss or soft tissue failure in multiply revised cases. We describe a technique for producing an on-table, static, reinforced cement spacer - the 'apple core' spacer - with the intended outcome of providing joint stability in such patients, prior to undertaking a second-stage procedure. Following a radical debridement, the spacer is made of three components: (1) a 'central bar' of external fixator connecting rods, combined using cerclage wires as needed; (2) a standard polymethylmethacrylate cement 'apple core'; and (3) a covering 'skin' of high dose antibiotic-loaded cement, which is stippled as it sets, to increase the surface area and facilitate antibiotic elution. This technique was performed in nine patients who underwent two-stage salvage revision for complex, recurrent infected total knee arthroplasty at a single institution. All patients successfully went on to definitive second-stage reimplantation and have retained their limbs. The 'apple core' cement spacer allows massive bone defects to be effectively managed between staged revision procedures.

Patellar complications following total knee arthroplasty: a review of the current literature.

Total knee arthroplasty is a common operation for treating patients with end-stage knee osteoarthritis and generally has a good outcome. There are several complications that may necessitate revision of the implants. Patella-related complications are difficult to treat, and their consequences impact the longevity of the implanted joint and functional outcomes. In this review, we explore the current literature on patellar complications in total knee arthroplasty and identify risk factors as well as strategies that can help in preventing these complications. We present pertinent findings relating to patellar complications. They can be classified into bony or soft tissue complications and include bone loss, aseptic loosening, periprosthetic fractures, patella fracture, patellar clunk syndrome, patellofemoral instability, extensor mechanism complications, maltracking, patella baja and malrotation. We conclude that patellar complications in total knee arthroplasty are common and have significant implications for the functional outcome of total knee arthroplasty. A high index of suspicion should be maintained in order to avoid them. Implant malpositioning and other forms of intraoperative technical error are the main cause of these complications, and therefore, primary prevention is crucial. When dealing with these established problems, a clear plan of action should be formulated in advance to allow appropriate management as well as anticipation of adverse outcomes.

Why are revision knee replacements failing?

AIM: The number of knee revisions worldwide has been steadily increasing. While being complex and expensive operations, a high percentage of knee revisions fail early. This study was conducted to evaluate the causes of failure of revision knee replacements. PATIENTS AND METHODS: This study retrospectively evaluated 95 patients following knee revision surgery and who underwent further knee revision operations. Indications for index revision as well as the reason for re-revision were recorded. Follow-up was from 30 to 97 months (mean 62 months). RESULTS: The main cause of failure of revision knee replacements was infection (31 of 95, 32.6%) followed by aseptic loosening (30.5%). Indications for re-revision were instability in 12.6%, persistent stiffness in 10.5%, ongoing pain in 7.3%, extensor mechanism problems in 5.2%, and suspected metal allergy in one. CONCLUSION: Infection and loosening continue to be the main reasons for failure of knee revisions. Improving outcomes for infection management and improved fixation methods may help reduce failed knee revisions.

Total knee arthroplasty in patients with prior adjacent multi-organism osteomyelitis.

Joint degeneration may make a total knee replacement a requirement for pain relief and function, however the presence of adjacent osteomyelitis makes management extremely challenging. We describe a series of four patients with a mean age of 50 with multi-organism osteomyelitis who underwent single-stage total knee replacements at an average of 63 months following eradication. Three patients did well but had complications associated with poor skin and soft tissues, and abnormal bone anatomy. One patient developed an infection and following a re-revision had an arthrodesis. The final mean Knee Society Score and Oxford Knee Score was 62 (54-66) and 34 (29-38) respectively. We have highlighted that these are a difficult cohort of patients to manage and their care is optimised through a multi-disciplinary approach by a high volume surgeon.

Metaphyseal sleeves in revision total knee arthroplasty: Minimum seven-year follow-up study.

BACKGROUND: Metal metaphyseal sleeves are an option for reconstruction as well as enhancing fixation in managing challenging bone defects in revision knee replacement. We report our results of revision knee replacement using metaphyseal sleeves with a minimum of seven years of follow-up. METHODS: The records of 103 patients (104 knees) who underwent revision knee replacement using metaphyseal sleeves in our centre were evaluated. The follow-up included clinical assessment, functional scores and radiologic assessment. RESULTS: The mean age of patients was 74.7 (tange 58-92) years. Mean follow-up was 95.7 (range, 88-115) months. From the original cohort, 15 (14%) patients had died from unrelated causes. During the follow-up period, there were 23 (22.1%) re-revisions. Indications for re-revision was aseptic loosening in seven (6.7%), stiffness in four (3.8%), infection in five (4.8%), instability in three (2.8%) and persistent pain in two (1.9%) patients. For aseptic loosening, the average time for re-revisions was 56.6 months (range 25 to 84). Radiographically, all unrevised sleeves were well-fixed, without any evidence of loosening. Oxford knee score in patients without re-revisions was 28.5 (range four to 48). CONCLUSION: At mid-term follow-up, metaphyseal sleeves demonstrate durable clinical results and radiographic fixation.