Total knee arthroplasty for primary knee osteoarthritis: Changing pattern over the past 10 years

Objective: To review the epidemiology of total knee arthroplasty for primary osteoarthritis and the change of patient characteristics over the last decade. Design: Retrospective review. Setting: A tertiary referral centre for joint replacement surgery in a teaching hospital in Hong Kong. Patients: All patients who underwent primary total knee arthroplasty for primary knee osteoarthritis from January 2000 to December 2009. Results: In all, 1157 total knee arthroplasties (589 left and 568 right) were performed on 588 females and 162 males. The annual number of total knee arthroplasties increased from 91 in 2000 to 181 in 2009. The annual number of patients increased from 58 (46 female, 12 male) in 2000 to 159 (117 female, 42 male) in 2009. When compared yearly results, there were no significant changes in the preoperative Knee Society Knee Score, Knee Society Functional Assessment, and passive range of motion of these patients. However, there was a significant decreasing trend with regard to lower limb mechanical axis mal-alignment, from 15.1° deviation from the neutral axis in 2000, to 14.8° deviation in 2004, and then 12.9° deviation in 2009 (mostly varus deformity). There was no difference between left knees and right knees, and between females and males. The mean age of the patients did not show significant change over the past decade, but the number and proportion of patients over 80 years old showed an increase from 4.8% (2000 to 2004) to 13.8% (2005 to 2009). On the other hand, the number and proportion of patients under the age of 60 years did not change. Conclusions: There was an increasing trend towards total knee arthroplasties, both in terms of number of operations and patients. The number of younger patients having total knee arthroplasty did not increase over the last 10 years, whereas the number of those older than 80 years increased significantly over that period.published_or_final_versio

Why do Hong Kong patients need total hip arthroplasty? An analysis of 512 hips from 1998 to 2010

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Antibiotic prophylaxis after total joint replacements

Objectives: To review the latest evidence on antibiotic prophylaxis for patients with total joint replacements to prevent prosthesis infections. Data sources: Literature search of Medline and PubMed until June 2009. Study selection: Studies of patients with total joint replacements from around the world, studies concerning antibiotic prophylaxis, as well as chemoprophylaxis guidelines from orthopaedic associations were searched. Data extraction: Literature review, original articles, case reports, best practice guidelines. Data synthesis: With the rising incidence of patients with total joint replacements, subsequent deep infection of the implants is a rare but dreaded complication which has immense physiological, psychological, financial, and social implications. Guidelines from urologists, gastroenterologists, and dental surgeons attempt to identify high-risk patients who may be more susceptible to prosthetic joint infections. These patients are provided with prophylactic antibiotics before any invasive procedure that may cause bacterial seeding to prosthetic joints. Most orthopaedic associations around the world adopt a similar policy to provide prophylaxis to cover any anticipated chance of bacteraemia. The American Association of Orthopaedic Surgeons adopts the most cautious approach in which all patients with total joint replacements who undergo any procedure that breaches a mucosal surface receive prophylactic antibiotics. Conclusion: The guidelines from the American Association of Orthopaedic Surgeons seem to have an all-encompassing policy when it comes to providing prophylactic antibiotics. Nonetheless, physicians must still exercise their judgement and customise the treatment to each patient. The benefits of prophylactic antibiotics must be balanced against the risks of drug side-effects and the emergence of antibiotic resistance.published_or_final_versio

Perioperative antithrombotic management in joint replacement surgeries

Objectives To determine optimal perioperative antithrombotic management for patients with cardiac diseases undergoing joint replacement surgeries. Data sources MEDLINE and PubMed database search up to January 2013. Study selection Those dealing with perioperative antithrombotic management of patients undergoing orthopaedic operations, especially joint replacement, and also those undergoing general surgery. Various combinations of the following key words were used in our search: 'antiplatelet', 'antithrombotic', 'anticoagulant', 'coronary stent', 'perioperative', 'venous thromboembolism', 'cardiovascular', 'surgery', 'orthopaedic', 'knee replacement', 'hip replacement', 'joint replacement', and 'arthroplasty'. Data extraction Literature review, original articles, and best practice guidelines. Data synthesis Patients should be stratified according to their risk of developing arterial thromboembolism in order to decide the most appropriate perioperative antiplatelet or anticoagulant regimen for them. After recent coronary stenting, including bare-metal stents implanted within 6 weeks and drug-eluting stents implanted within 6 months, surgery should be deferred. For venous thromboembolism prophylaxis in patients already on aspirin, the dosage should be adjusted as necessary or additional low-molecular-weight heparin administered. Conclusion The perioperative management of patients with cardiac diseases in receipt of antithrombotic agents is based upon a delicate balance between the perceived risk of arterial thromboembolism and the perceived risk of perioperative bleeding. One must exercise good judgement in deciding the most appropriate perioperative antithrombotic regimen. Venous thromboembolism is also a common problem after joint replacement surgeries. For patients already on aspirin, optimal venous thromboembolism prophylaxis is still being debated.published_or_final_versio

Review article: Venous thromboembolism after total joint replacement

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Surgical debridement with prostheses retention for the treatment of acute periprosthetic infections following total knee arthroplasty

Free Paper Presentation Session 6 – Adult Joint Reconstruction: no. 6.3INTRODUCTION: Periprosthetic infection after total knee arthroplasty (TKA) is difficult to treat. Surgical debridement with retention of prostheses is one of the valid methods ...postprin

Case series of Jehovah's witnesses having Total Knee Arthroplasty in Hong Kong

Electronic Poster Presentations: P48INTRODUCTION: Total knee arthroplasty (TKA) is challenging in Jehovah’s Witnesses (JW), as they do not accept transfusions. We report our experiences with a series of TKAs in JW in our ...postprin

Fracturing ranked surfaces

Discretized landscapes can be mapped onto ranked surfaces, where every element (site or bond) has a unique rank associated with its corresponding relative height. By sequentially allocating these elements according to their ranks and systematically preventing the occupation of bridges, namely elements that, if occupied, would provide global connectivity, we disclose that bridges hide a new tricritical point at an occupation fraction $p=p_{c}$, where $p_{c}$ is the percolation threshold of random percolation. For any value of $p$ in the interval $p_{c}< p \leq 1$, our results show that the set of bridges has a fractal dimension $d_{BB} \approx 1.22$ in two dimensions. In the limit $p \rightarrow 1$, a self-similar fracture is revealed as a singly connected line that divides the system in two domains. We then unveil how several seemingly unrelated physical models tumble into the same universality class and also present results for higher dimensions

Narrowband Biphotons: Generation, Manipulation, and Applications

In this chapter, we review recent advances in generating narrowband biphotons with long coherence time using spontaneous parametric interaction in monolithic cavity with cluster effect as well as in cold atoms with electromagnetically induced transparency. Engineering and manipulating the temporal waveforms of these long biphotons provide efficient means for controlling light-matter quantum interaction at the single-photon level. We also review recent experiments using temporally long biphotons and single photons.Comment: to appear as a book chapter in a compilation "Engineering the Atom-Photon Interaction" published by Springer in 2015, edited by A. Predojevic and M. W. Mitchel

Mild component malalignment may not affect the postoperative range of motion in posterior-stabilised total knee arthroplasty

Free Paper Presentation Session 6 – Adult Joint Reconstruction: no. 6.11INTRODUCTION: The optimal lower limb alignment and component positions in achieving a high flexion angle in posterior-stabilised total knee arthroplasty (TKA) were not well understood. We analysed pre- and post-operative clinical and radiological parameters in patients received TKA for knee ...postprin