Role of Anatomical Patella Replacement on Anterior Knee Pain.

BACKGROUND: Anterior knee pain (AKP) remains a complex issue affecting patient satisfaction after total knee arthroplasty. Several radiographic parameters have been shown to be causative factors with various designs. The aim of this study is to evaluate the known radiographic parameters of AKP and clinical outcomes (ie, AKP) in the setting of a modern prosthesis with an anatomic patella button. METHODS: Between July 2012 and December 2013, 90 total knee arthroplasties received 3 skyline views taken at 30°, 45°, and 60°. A patient-administered questionnaire was administered at 2-year follow-up to assess the incidence of AKP, painless noise, and satisfaction. Radiographs were analyzed for patellofemoral overstuffing, patellar tilt, and patellar displacement, and evaluated the patella resection angle. RESULTS: On the patient-administered questionnaire, 10 (11.1%) patients reported AKP of a mild-to-moderate nature. Thirty-one had the best view at 30 Merchant views, 24 had best views at 45, and 35 had best views at 60. We found that patellar resection angle correlated with AKP (odds ratio 1.21, P = .044) and painless noise (odds ratio 1.22, P = .034). Patellar displacement and patellofemoral stuffing did not correlate with AKP or painless noise. No radiographic measurements correlated with changes in Knee Society Score pain or function scores or range of motion. CONCLUSION: We found that a patellar resection angle correlated with the incidence of AKP and painless noise at 2-year follow-up. We failed to find any correlation with patellofemoral overstuffing, patellar displacement, or patellar tilt with clinical outcomes. We recommend the use of 3 Merchant views to fully evaluate the patellofemoral joint.

Acute Kidney Injury after Total Knee Arthroplasty: A Clinical Review.

INTRODUCTION: Patients who develop acute kidney injury (AKI) have an increased risk for progression to chronic kidney disease, end-stage renal disease, and increased mortality. The outcomes of total knee arthroplasty (TKA) patients who develop AKI have remained controversial. The purpose of this review was to summarize and identify the current literature focused on 1) major risk factors, 2) short-term outcomes, and 3) costs associated with the development of perioperative AKI after TKA. MATERIALS AND METHODS: A literature search was performed using PubMed and Ovid to find literature relevant to AKI in TKA. All abstracts found via literature search were screened for relevancy to the study topics: (1) risk factors, (2) short-term outcomes, and (3) cost. RESULTS: A total of 447 abstracts were initially identified. Irrelevant abstracts and those not in English were excluded from the study (n=336). Forty-five papers focused on risk factors associated with AKI, six papers focused on short-term outcomes, and seven discussed cost savings. Increased body mass index, metabolic syndrome, perioperative antibiotics, antihypertensive medications, and antibiotic-impregnated cement spacers are amongst the many modifiable patient and drug-induced risk factors associated with AKI after TKA. Perioperative renal injury is associated with increased inpatient and long-term mortality with increased length of stay and extended care facility discharge. CONCLUSION: Increased length of stay and comorbidities have shown higher cost utilization and readmission rates. Inpatient and long-term complications and mortality are associated with postoperative AKI and a multidisciplinary perioperative approach is necessary to appropriately identify and, ultimately, prevent patients at higher risk for acute renal failure.