Left Total Knee Arthroplasty Research Articles

Atraumatic Lateral Tibial Plateau Periprosthetic Insufficiency Fracture after Primary Total Knee Arthroplasty: A Case Report

Tibial Periprosthetic fractures (PPF) after primary total knee arthroplasty (TKA) are uncommon and mainly occur after trauma. Various management options have been proposed; however, the decision mainly relies on the location of the fracture and the tibial baseplate stability and ranges between conservative (non-operative), fracture fixation, and revision TKA. We report a case of a 79-year-old female patient who presented with atraumatic lateral tibial plateau PPF (Felix type ⅠB) with a loose tibial implant after three weeks of having left primary TKA. The patient was treated successfully by revising the tibial component using a stemmed tibial baseplate and reconstructing the tibial bone defect using two metal wedges. The radiological, functional, and PROM outcomes were satisfactory and accepted both early on (eight weeks) and at the last follow-up (six months). Atraumatic insufficiency Felix type ⅠB PPF of the lateral tibial plateau after primary TKA is uncommon. Reconstructing the tibial bone defect, revising the tibial component, and adding a stem to offload the tibial plateau are the treatments of choice that lead to acceptable outcomes.

Granulicatella adiacens: An uncommon pathogen in prosthetic joint infections

Granulicatella adiacens is an uncommon culprit in prosthetic joint infections, especially when predisposing factors are absent. Here, we present the case of a 78-year-old female who developed an acute surgical site infection shortly after undergoing left total knee arthroplasty. Despite initial negative cultures, subsequent analysis identified Granulicatella adiacens in the knee fluid, marking only the second reported instance in the United States and the seventh globally. This singular case highlights the considerable challenges associated with isolating this organism, emphasizing its atypical presentation and diagnostic elusiveness. Typically associated with endocarditis and bacteremia, its involvement in isolated surgical site infections is particularly unusual. Our case underscores the necessity for heightened clinical suspicion and the adoption of specialized diagnostic methodologies to accurately detect Granulicatella adiacens infections. Given its fastidious nature and nutritional requirements, standard culture methods may fail to identify this pathogen, necessitating alternative diagnostic approaches. As such, the utilization of specialized media becomes paramount in clinical diagnostics to facilitate appropriate management and optimize healthcare resource allocation. By enhancing our ability to detect and treat infections caused by Granulicatella adiacens, we can mitigate patient morbidity and reduce the burden of unnecessary interventions, thereby improving patient outcomes and healthcare efficiency.

Determination of the effect of preoperative knee joint function on postoperative quality of life in patients with total knee arthroplasty.

Primary total knee arthroplasty (TKA) is one of the most successful procedures for end-stage knee osteoarthritis. To determine the effect of preoperative knee joint function on postoperative quality of life in patients undergoing primaryTKA. This descriptive cross-sectional study was conducted with a total of 208 patients in the orthopedics and traumatology clinic. Data were gathered with a personal information form, the Oxford Knee Score (OKS), and the EQ-5D-5L Quality Of Life Scale in the preoperative period,at postoperative 6th week, and at postoperative 3rd month. The data were analyzed using descriptive statistics, one-way analysis of variance (ANOVA), correlation analysis, and simple linear regression analysis. The mean age of the patients was 65.65 ± 7.01 years. Most patients (86.1%) were women, and 51.4% underwent left TKA. OKS scores indicated poor knee function preoperatively and gradually increased at postoperative 6th week and 3rd month. Preoperative OKS was a significant predictor of postoperative knee joint function and quality of life. This study shows that preoperative knee joint function significantly affects postoperative knee joint function and quality of life. These results demonstrate the importance of the surgery timing and suggest that performing surgery earlier in functional decline may be associated with a better outcome.

Investigation of Reaction Time, Proprioception, and Shaped Pathway Walking Performance in Older Patients with Total Knee Arthroplasty

ObjectivesThe existing literature on total knee arthroplasty (TKA) does not provide clear data on step reaction time and proprioception and gait in shaped pathways. This study investigated the relationship between proprioception and reaction time with walking performance in shaped pathways in older patients undergoing TKA. DesignA cross-sectional observational study. Setting and ParticipantsAn orthopedic outpatient clinic with 103 older patients with TKA after a minimum of 6 months after surgery. MethodsParticipants were evaluated with Figure-of-8 Walk Test (F8WT), L Test, Tinnetti Gait Test (TGT), proprioception measurement with an app-based inclinometer, and step reaction time (SRT) test. The same assessor carried out all evaluations. ResultsF8WT showed a strong correlation with SRT-right, SRT-left, and Tinetti Gait Test (TGT), respectively (r1 = 0.628, r2 = 0.619, r3 = −0.615, P < .01). In addition, F8WT was moderately correlated with Right Leg Proprioception Test (RLPT) and Left Leg Proprioception Test (LLPT), respectively (r1 = 0.487, r2 = 0.439, P < .01). There was a moderate correlation between L Test with RLRT, LLRT, and TGT, respectively (r1 = 0.597, r2 = 0.584, r3 = −0.542, P < .01). Besides, there was a weak positive correlation between L Test with RLPT and LLPT, respectively (r1 = 0.394, r2 = 0.335, P < .01). A regression model showed that the L test was related to RLRT, LLRT, and TGT (R2 = 0.432, P < .001). The higher ability of the L test was weakly associated with higher levels of TGT (standardized β = −0.28, P = .0012). Besides, regression analysis also proved that F8WT was related to RLRT, LLRT, and TGT (R2 = 0.522, P < .001). The most highly associated parameter was LLRT (standardized β = 0.958, P = .003). Conclusions and ImplicationsGait in shaped pathways is associated with proprioception, reaction time, and balance ability in older patients with TKA. Therefore, proprioception, reaction time, and balance should be considered to improve the shaped pathway walking performance of patients after bilateral, right, or left TKA surgery.

Prosthetic knee joint infection caused by α-hemolytic Streptococcus species: a case report

BackgroundKnee arthroplasty is an orthopedic surgical procedure in which a damaged joint is replaced with an artificial one. It is estimated that 1–2% of knee arthroplasties will encounter infection over their lifetime. Although α-hemolytic Streptococcus species play an important role in prosthetic joint infection, they are less common than staphylococcal species.Case presentationIn this report, a 50-year-old Iranian woman was diagnosed with prosthetic knee joint infection based on clinical, radiological, and laboratory findings. She was diabetic and had undergone a left total knee arthroplasty, which, 18 months after the surgery, presented pain, erythema, and edema in that knee. The primary culture of knee aspirate was positive for α-hemolytic Streptococcus species, but following antibiotic medication, culture was negative. The primary antibiotic regime was vancomycin and meropenem, which was changed to cefepime for the management of the infection based on the results of antimicrobial susceptibility testing.ConclusionsThis report indicated the clinical presentation and management of the patient with prosthetic joint infection in which the patient recovered without any severe complications or surgical intervention.

FUNCTIONAL IMPROVEMENTS MEASURED BY THE CONTINUOUS-SCALE PHYSICAL FUNCTIONAL PERFORMANCE TEST IN A UNILATERAL TRANSFEMORAL AMPUTEE FOLLOWING SOUND SIDE KNEE ARTHROPLASTY: A CASE STUDY

Osteoarthritis is common in the sound limb of persons with a transfemoral amputation (TFA) due to gait abnormalities and increased load on the knee when ambulating with or without aprosthesis. Commonly, a sound-limb total knee arthroplasty (TKA) is required to decrease pain and improve physical function. This case report discusses physical functional outcomes in a person with a TFA following sound limb TKA as measured by the Continuous-Scale Physical Functional Performance Test 10 (CS-PFP 10). A patient with a right TFA underwent a left TKA to improve functional performance. The purpose of this case was to quantify functional changes measured by the CS-PFP 10 at one week pre-TKA and one, three, six, twelve, and eighteen months post-TKA. Skilled standard care physical therapy was immediately implemented post-TKA, which included therapeutic interventions and electrotherapeutic modalities. Additionally, a whole-body high-intensity strengthening program was introduced at eighteen weeks post-operative (post-op) as an adjunct to return the patient to his prior level of function as a CrossFit® athlete.All five CS-PFP 10 domains demonstrated continuous improvement, while the rate of perceived exertion decreased. At one week post-op, the patient’s CS-PFP 10 score indicated an increased likelihood of functional dependence. However, by eighteen months, the patient achieved a total CS-PFP 10 score in the 75 to 90 range, indicating independent function likely. The CS-PFP 10 is a valid instrument to measure improvement in activities of daily living (ADL) in specified functional domains and overall function. Following this patient post-operatively through rehabilitation, the CS-PFP 10 revealed objective improvements demonstrating that sound limb total joint arthroplasty and physical therapy can greatly improve function. These interventions are a viable course of treatment in the presence of contralateral functional impairment in patients with TFA.The CS-PFP 10 is a valid instrument to accurately measure improvements in ADLs in specified functional domains and overall function in the patient population with a TFA followingsound limb TKA.

Acremonium (Sarocladium) periprosthetic joint infection: case report, literature review, and proposed antifungal regimen

BackgroundFungal periprosthetic joint infections are rare. Acremonium osteoarticular infections are scarcely reported. Variable susceptibility to antifungal agents have been reported and optimal pharmacotherapy has yet to be established. Here we illustrate an Acremonium osteoarticular infection involving a prosthetic joint and present an antifungal regimen that had led to treatment success.Case presentationA 60-year-old female with a body mass index (BMI) of 40 had left total knee arthroplasty done in 2012 with a cementless implant for knee osteoarthritis. In 2019, the patient had asymptomatic, progressive osteolysis with fracture and migration of the femoral component warranting replacement. Eleven months later, the patient developed significant pain, redness, and swelling in the left leg and knee concerning for periprosthetic joint infection that failed outpatient antibiotic treatment. Further investigation revealed infection by Acremonium species. A revision of the joint was successfully completed, and the patient was placed on voriconazole for one year. Subsequent cultures did not yield any fungal growth.ConclusionWhile an optimal antifungal regimen for periprosthetic joint infections has not been well established, voriconazole is a relatively safe and effective agent that can be used as a long-term therapy. With variable susceptibility testing in reported isolates, individualized antifungal susceptibility should be used to guide therapy for Acremonium infections.

Total Knee Arthroplasty Complicated by Diffuse Large B-Cell Lymphoma

A 74-year-old male with a prior left total knee arthroplasty presented with deformity, loosening, pain, and stiffness associated with multiple raised, erythematous, cutaneous nodules about the anterior knee. Workup was concerning for infection, but the skin nodules were atypical. The patient was sent for biopsy which revealed cutaneous diffuse large B-cell lymphoma. The revision surgery was delayed, and the patient underwent chemotherapy/radiation with complete resolution of his lymphoma. He then underwent a successful aseptic revision total knee arthroplasty. Proper identification and treatment of rare cutaneous skin lesions about a prior surgical site can limit morbidity and result in more desirable outcomes.

Prosthetic Joint Infection Due to Cardiobacterium hominis: Report of First Known Case and Review of C. hominis Septic Arthritis Literature

Introduction. The Cardiobacterium species is a pleomorphic Gram-negative bacterium discovered in 1964 and is part of the HACEK (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, and Kingella) group of organisms known to cause endocarditis. It has low virulence and can also cause dacryocystitis, septicemia and abdominal abscess. We report a patient with C. hominis prosthetic joint infection in the absence of definitive endocarditis. Case Report. A 57-year-old man presented to his orthopedic surgeon 17 months after left total knee arthroplasty with a 4–5-day history of left knee pain following yard work. He had an aortic valve replacement in 2003, mitral valve repair in 2006 and bovine aortic valve replacement in 2019 (12 months previously). Aspirate of knee joint fluid was grossly cloudy. Two of two preoperative blood cultures revealed Cardiobacterium species after 4 days’ incubation. He was initially treated with intravenous vancomycin plus piperacillin/tazobactam followed by 6 weeks of parenteral ceftriaxone followed by five months of oral cefdinir. Patient is infection-free 6 months after completion of antimicrobial therapy. Discussion. Cardiobacterium hominis is a slow-growing, fastidious, capnophilic, Gram-negative bacillus commonly found in normal oral and upper respiratory flora. Google Scholar™ and PubMed®searches were conducted and this is the first reported case of prosthetic joint infection due to Cardiobacterium hominis. We found three previously reported cases of C. hominis pyogenic arthritis: one patient with native knee pyogenic arthritis, one patient with cervical spondylodiscitis and one patient with lumbar spondylodiscitis and epidural abscess. Two of these three patients had TEE-documented infective endocarditis and one had a bioprosthetic aortic valve without evident vegetation on TEE. Our patient had a bioprosthetic aortic valve without TEE evidence of endocarditis. C. hominis should be added to the list of organisms that can cause bacteremically spread prosthetic joint infection.

The challenge of antibiotic selection in prosthetic joint infections due to Corynebacterium striatum: a case report

BackgroundCorynebacterium striatum is a gram-positive facultative anaerobe found in the environment and human flora that has historically been considered a contaminant. More recently, Corynebacterium striatum has been implicated in human infections, including respiratory infections, endocarditis, and bone and joint infections, particularly those involving hardware or implanted devices.Case presentationA 65-year-old man presented for washout of his left total knee arthroplasty following a revision 20 days prior. The patient underwent debridement of his left total knee and revision of the left total femur arthroplasty. Daptomycin was initiated empirically due to a previous rash from vancomycin. Operative tissue cultures grew Staphylococcus haemolyticus, Staphylococcus epidermidis and Corynebacterium striatum. Given concern for daptomycin resistance and the reliability of vancomycin susceptibility, daptomycin was discontinued and vancomycin initiated following a graded challenge. Within a few days, the patient developed a diffuse, blanching, erythematous, maculopapular rash and daptomycin was restarted. Over the next 72 h, his rash progressed and he met criteria for drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome. Daptomycin was stopped and oral linezolid initiated; rash improved. C. striatum returned with susceptibility to gentamicin, linezolid, vancomycin and daptomycin. Due to concern for adverse effects on long-term linezolid, daptomycin was restarted and was tolerated for 20 days, at which point purulent drainage from incision increased. The patient underwent another arthroplasty revision and washout. Operative cultures from this surgery were again positive for C. striatum. Repeat C. striatum susceptibilities revealed resistance to daptomycin but retained susceptibility to linezolid. Daptomycin was again changed to linezolid. He completed six weeks of linezolid followed by linezolid 600 mg daily for suppression and ultimately opted for disarticulation.ConclusionsC. striatum has historically been regarded as a contaminant, particularly when grown in tissue culture in the setting of prosthetic joint infection. Based on the available literature and susceptibility patterns, the most appropriate first-line therapy is vancomycin or linezolid. Treatment with daptomycin should be avoided, even when isolates appear susceptible, due to the risk of development of high-level resistance (MIC > 256 µg/mL) and clinical failure.

Complex total knee arthroplasty in a patient with bone cement allergy: A case report

Case: Total knee arthroplasty (TKA) is a common surgical procedure, with annually increasing numbers worldwide, and the great majority of TKAs utilize polymethyl methacrylate (PMMA) bone cement on a routine basis. However, there has been little awareness of hypersensitivity reactions to bone cement components which can potentially lead to serious adverse effects. We report the case of a 44-year-old female with severe knee arthritis and medically-warranted need for left TKA who had allergy to bone cement components. The allergy was fortuitously identified preoperatively, and the use of specialized implant components that removed the risk of exposure to the allergens helped to avoid potential complications. Conclusion: Conscientious preoperative evaluation and planning will help to identify and manage patients with bone cement allergy. We report this case as it is an uncommon but yet medically significant case of complex primary TKA with multiple special requirements, each presenting a different learning point.

Sol Total Diz Artroplastisi Sağ El Dominant Cerrah İçin Neden Daha Zordur? Total Diz Artroplastisinde Taraf Analizi

Objective: We hypothesize that right-handed surgeons can achieve equally successful results in both right and left sides of patients, although they are exposed to more occupational damage when performing knee arthroplasty on the left side.Material and Methods: A total of 246 (113 right and 133 left) total knee prosthesis operations performed by two right-handed orthopaedic surgeons in our institution were included. Patients were divided into right and left knee arthroplasty groups for comparison. The demographic data of the patients, the knee range of motion (ROM), hip-knee-ankle angle (HKAA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and Knee Society Score (KSS) values were evaluated for all groups. Moreover, electromyographic measurements of specific muscle groups, which were used while performing the right and left total knee arthroplasty procedures, were taken for the two surgeons to compare the differences in efficacy of surgeries performed on different sides.Results: There was no statistically significant difference between the two groups when the postoperative bleeding volumes and flexion, extension levels, and pain and function scores at 3 months and 1 year were compared There was no significant difference between groups in term of postoperative ROM, HKAA, LDFA, MPTA, and KSS values. It was observed that the right latissimus dorsi muscles of the surgeons exhibited about five times more activation, the left latissimus dorsi muscles exhibited three times more activation, and the left gluteus medius muscles exhibited two times more activation during left knee surgery than right knee surgery.Conclusion: Right-handed surgeons can provide equally good results when operating left knees as right ones, although they exert more effort when performing left-sided arthroplasty. However, we conclude that left knee surgeries cause more occupational damage for surgeons.

Return-to-Driving Recommendations After Lower-Extremity Orthopaedic Procedures.

Following lower-extremity orthopaedic surgery, recommendations for safe return to driving include at least 6 to 12 weeks for a right ankle fracture, 2 days to 2 weeks for a right ankle arthroscopy, 6 to 9 weeks for a total ankle arthroplasty, 6 to 7 weeks for a right Achilles tendon rupture repair, 1 to 4 weeks for a right total knee arthroplasty, 2 weeks for a left total knee arthroplasty, 3 to 6 weeks for a right anterior cruciate ligament repair, and 1 to 4 weeks for a total hip arthroplasty. Important individual factors such as extent of injury, laterality of injury, current driving habits, type of vehicle transmission (manual or automatic), and medical comorbidities must be taken into consideration. State laws vary widely and often use vague language to describe the legal responsibilities that orthopaedic surgeons have when providing return-to-driving recommendations.

Elective Total Knee Replacement in a Patient With a Left Ventricular Assist Device–Navigating the Challenges With Spinal Anesthesia

ELECTIVE joint surgery in a patient with a left ventricular assist device (LVAD) may become increasingly common as these devices become entrenched in the management of patients with heart failure.1,2 Furthermore, regional techniques may be reasonable anesthetic options in this challenging population.3,4 This case conference discusses a spinal anesthetic for an elderly female with an LVAD who presented for an elective left total knee arthroplasty. The expert case commentaries that follow the case discussion further explore the anesthetic issues in light of the existing literature.

Fungal arthritis with adjacent osteomyelitis caused by Candida pelliculosa: a case report

BackgroundCandida sp. osteoarticular infection is rare and most often due to hematogenous seeding during an episode of candidemia in immunocompromised patients. However, the diagnosis can be delayed in patients with subtle symptoms and signs of joint infection without a concurrent episode of candidemia.Case presentationA 75-year-old woman presented with a three-year history of pain and swelling of the left knee. Candida pelliculosa was detected from the intraoperative tissue when the patient had undergone left total knee arthroplasty 32 months ago, but no antifungal treatment was performed. One year after the total knee arthroplasty, C. pelliculosa was repeatedly isolated from the left knee synovial fluid and antifungal treatment comprising amphotericin B deoxycholate and fluconazole was administered. However, joint infection had extended to the adjacent bone and led to progressive joint destruction. The patient underwent surgery for prosthesis removal and received prolonged antifungal treatment with micafungin and fluconazole.ConclusionsThis case shows that C. pelliculosa, an extremely rare non-Candida albicans sp., can cause fungal arthritis and lead to irreversible joint destruction owing to delayed diagnosis and treatment.

Arthrodesis with Retrograde Intramedullary Nail for Recurrent Infected Total Knee Arthroplasty with Patellar Tendon Rupture: A Case Report and Literature Review

Patellar tendon rupture after total knee arthroplasty is a rare, but often catastrophic complication. In addition, infection is also a dreaded complication after total knee arthroplasty. We report an 84-year-old female that has late infected total knee arthroplasty with patellar tendon rupture treated with resection arthroplasty and then subsequent arthrodesis with retrograde intramedullary nail.Case Presentation:The 84-year-old female underwent left total knee arthroplasty 2 years ago and revision arthroplasty last year after trauma. She presented to the emergency department with painful disability of left knee. The septic arthritis of left knee was confirmed by bacterial culture through arthrocentesis which yielded methicillinsensitive staphylococcus aureus. Patellar tendon rupture was also noted by loss of extension mechanism and patella alta in plain films. Despite attempts on open debridement and parenteral antibiotics, the infection did not settle. Resection arthroplasty with vancomycin- impregnated cement spacer implantation was performed following by 4-week parenteral antibiotics therapy. The ESR and CRP level of serum improved gradually. Arthrodesis of left knee with retrograde locking intramedullary femoral nail through single incision of the knee was performed. Protected weight bearing was allowed in one week after arthrodesis. The patient discharged 2 weeks later without recurrent infection, but leg length discrepancy about 2cm was noted.Discussion:Patellar tendon rupture after total knee arthroplasty is a rare but disabling complication whose management is often difficult. It was reported that incidence of patellar tendon rupture in literature varies between 0.3- 12.4% for primary total knee arthroplasty and between 1-15% for revision total knee arthroplasty. Contributing factors are excessive dissection and knee manipulation, and trauma. In the literature, various different operative techniques and rehabilitation programs have been described indicating the lack of a golden standard treatment protocol. However, in patients with a total knee arthroplasty, the results have been discouraging. Reconstruction of the patellar tendon can be utilized semitendinosus-gracilis graft with an interference screw and a staple fixation in treating acute ruptures, whereas allografts and synthetic mesh are indicated for chronic cases. Nevertheless, treatment outcomes for ruptured patellar tendon are not good. Gold standard treatment of infected total knee arthroplasty was resection arthroplasty with antibiotic-impregnated bone cement spacer and parenteral antibiotics therapy and then second stage revision total knee arthroplasty until the infection is eradicated. The patella tendon repair and second revision arthroplasty were not suggested by Jake et al. Patellar tendon rupture is best treated with primary repair, but infected prosthetic knee with patellar tendon rupture seemed to be more difficult to manage. Arthrodesis but not revision arthroplasty may be the best choice after infection control to improve the patient’s level of function.

A Case Report: Custom Made Porous Titanium Implants in Revision: A New Option for Complex Issues

Background: Bone loss management is considered one of the most difficult challenges for orthopaedic surgeon. In massive bone defects, few surgical options are available and they do not offer a reliable or optimal solution for knee reconstruction. Objective: The aim of this paper is to present and justify a new custom-made approach for complex metadiaphyseal bone defects management in knee revision surgery. Methods: We report a case of a 66-year-old woman who underwent a staged left total knee arthroplasty revision for infection with Anderson Orthopaedic Research Institute classification III uncontained femoral and tibial metadiaphyseal bone defects following five prior surgeries. Along with a case discussion, we describe clinical and radiological outcomes of 3 similar patients treated with this new custom-made device. Results: To manage these problems, we developed new, custom porous titanium devices for both femoral and tibial reconstruction tailored to a patient’s specific bone loss. Since, 2014, we treated four cases using custom-made porous titanium cones and we had optimal clinical and radiological results, with no instances of loosening, component migration, or mismatches between preoperative planning and intraoperative findings. Conclusion: In extremely selected cases, this new device can be considered a possible and viable surgical step between “off the shelf” reconstruction implants and knee substitution with a tumor megaprosthesis.

Reducing costly falls after total knee arthroplasty.

AIMTo investigate whether adductor canal nerve block (ACB) reduces patient falls when compared to femoral nerve block (FNB) after total knee arthroplasty (TKA).METHODSWe conducted an institutional review of all-cause falls after TKA from January 2013 to August 2016 using a quality improvement database. Our inclusion criteria were patients with diagnosis of primary knee osteoarthritis who underwent primary unilateral TKA with either a FNB or an ACB and sustained a fall during their hospitalization. We excluded patients who had revision TKA and extensor mechanism reconstruction. We also excluded patients with a history of post-traumatic arthritis, prior history of lower extremity fracture, history of neurological disease, or cerebrovascular disease.RESULTSA total of 834 patients had TKA with femoral nerve block and knee immobilizer (FNB + KI). Of those patients, 11 (1.3%) experienced a fall during their hospital stay. In contrast, 791 patients had TKA with ACB. Of those patients, only one (0.13%) patient fall was recorded within this group. We used the Fisher’s exact test to compare the differences between the two groups. The difference between the two groups achieves statistical significance (P = 0.006). We also found that 11 out of the 12 patients that fell had a right TKA procedure while one patient had a left TKA procedure. Nine out of twelve patients that fell were female, while only three patients were male.CONCLUSIONGiven the reduction in the number of falls with ACB, it is recommended that ACB be considered the preferred analgesia for patients undergoing a TKA procedure.

A CASE OF SPONTANEOUS HEPARIN-INDUCED THROMBOCYTOPENIA AND THROMBOSIS (HITT)

SESSION TITLE: Critical Care 2 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Spontaneous heparin-induced thrombocytopenia and thrombosis (HITT) is established with positive serum platelet factor 4 (PF4) antibody, thrombosis, and without prior heparin exposure. Only a handful of spontaneous HITT cases have been reported. Due to history of no exposure to heparin products, diagnosis is often challenging and treatment delayed leading to increased patient morbidity and mortality. Here we present a case of spontaneous HIT and thrombosis after a left total knee arthroplasty (TKA). CASE PRESENTATION: A 71 year old male presented on postoperative day (POD) 7 from left TKA with acute onset abdominal pain, bright red blood per rectum, and coffee ground emesis. Prior to his TKA, he was noted to have a platelet count of 185 x 103/uL. Post-operatively he was discharged on Clindamycin 600mg and Aspirin 325mg twice daily for deep venous thrombosis (DVT) prophylaxis. On admission, he was found to have a platelet count of 47 x 103/uL and further work-up revealed splenic vein and bilateral lower extremity deep venous thrombosis. Due to acute bleeding patient was not started on anticoagulation and an inferior vena cava filter was placed. On hospital day 3, patient became acutely short of breath and computed tomography angiogram of the chest revealed bilateral pulmonary artery emboli. Serum PF4 [define PF4 here] antibody resulted strongly positive at 3.004 optical density (OD) (Range: 0.0 – 0.4 OD) indicating HITT associated thrombosis. Once the serum PF4 antibody titer was resulted positive, patient was started on Argatroban drip with eventual increase in platelet count past 150 x 103/uL. DISCUSSION: HIT is a complication of exposure to heparin that could be life threatening. It is caused by autoantibodies that recognize and bind to highly antigenic multi-molecular complexes formed of heparin binding to endogenous protein PF4 and causing platelet activation.1 Multiple theories have been proposed but the exact mechanism behind spontaneous HIT remains unclear. In vitro studies have shown that heparin antibodies are not specific to heparin and can also recognize PF4 bound to other polyanions and have shown to be elicited by reaction with lipopolysaccharides from gram negative bacteria.2 This may explain why cases of spontaneous HIT are seen in patient following total knee or hip arthroplasty where significant limb ischemia and tissue injury occur. CONCLUSIONS: Although exceedingly rare, spontaneous HITT is important to be recognized early to reduce patient morbidity and mortality. Patients without prior exposure to heparin who have undergone orthopedic procedures and present with worsening platelet count or new arterial/venous thrombosis should be considered to have spontaneous HITT and treated accordingly. Reference #1: Rauova L, Zhai L, Kowalska MA, et al. Role of platelet surface PF4 antigenic complexes in heparin-induced thrombocytopenia pathogenesis: diagnostic and therapeutic implications. Blood 2006; 107:2346. Reference #2: G. Pongas, S. K. Dasgupta, and P. Thiagarajan, “Antiplatelet factor 4/heparin antibodies in patients with gram negative bacteremia,” Thrombosis Research, vol. 132, no. 2, pp. 217–220, 2013. Reference #3: Warkentin T.E., Cook R.J., Marder V.J., Greinacher A. Anti-PF4/heparin antibody formation postorthopedic surgery thromboprophylaxis: the role of nondrug risk factors and evidence for a stoichiometry-based model of immunization. J Thromb Haemost. 2010; 8:504. DISCLOSURES: No relevant relationships by Bryan Anderson, source=Web Response No relevant relationships by Chinthaka Bulathsinghala, source=Web Response No relevant relationships by Palla De Silva, source=Web Response No relevant relationships by Ahmed Hassan, source=Web Response No relevant relationships by aftab mahmood, source=Web Response No relevant relationships by Chirag Patel, source=Web Response Speaker/Speaker's Bureau relationship with Sunovian Please note: $5001 - $20000 Added 11/20/2017 by Salim Surani, source=Web Response, value=Honoraria Advisory Committee Member relationship with Astra Zeneca Please note: $5001 - $20000 Added 11/20/2017 by Salim Surani, source=Web Response, value=Consulting fee No relevant relationships by Deanna Yamamura, source=Web Response

What Is the Evidence on Which Physicians Can Rely to Advise Patients When They May Resume Driving after TKA? A Systematic Literature Review

Patients undergoing total knee arthroplasty (TKA) often ask when they can safely resume driving. Answering this question is an important matter, which might entail legal and insurance issues. In the present review, the following questions are addressed: What is the quality of the existing literature on this issue? When does the Brake Response Time (BRT) return to baseline values after right and left TKA? Are BRT components, reaction time (RT), and movement time (MT) equally affected after right and left TKA? Are there gender differences regarding the influence of TKA on BRT and its recovery? An electronic systematic search was performed on Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, and PubMed. Ten studies investigating the effects of TKA on driving performance were included. The quality assessment was made with a 12-item assessment tool adapted from the “Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies” of the National Institute of Health. The quality of the existing studies varies, with all studies having methodological weak points. TKA causes an MT delay, which affects BRT negatively. The mean number of days for BRT to return to baseline values was 44 ± 19 (95% C.I. [29 to 58]) and 20 ± 15 (95% C.I. [2 to 38]) after right and left TKA, respectively. As shown by the wide 95% C.I. of the mean, these values can increase to higher numbers. Based on the weighted mean values, a driving abstinence of at least six weeks after right TKA and three weeks after left TKA should be recommended. Due to the discrepancies found in results, further high quality studies are necessary.