Prophylactic Tibial Stem Fixation in the Obese: Comparative Early Results in Primary Total Knee Arthroplasty

PURPOSE: Obesity is a risk factor for aseptic loosening after total knee arthroplasty (TKA). Prophylactic use of tibial stems may enhance tibial fixation in obese patients. The aim of this study was to determine whether a tibial stem extension decreases rates of early failure in obese patients. MATERIALS AND METHODS: This study included 178 consecutive primary TKAs (143 patients) with a body mass index ≥35 kg/m2. Fifty TKAs were performed with the use of a 30 mm tibial stem extension, and 128 TKAs were performed with a standard tibial component. Patients with two-year clinical follow-up were included. The primary outcome was revision for aseptic loosening. Secondary outcomes were all-cause revision and radiolucent lines (RLLs) on radiographs. RESULTS: Average follow-up was 34 months (range, 24 to 46 months). No failures for aseptic loosening occurred. The occurrence of secondary procedures was not significantly different between groups. Quantification of RLLs revealed no difference between groups. CONCLUSIONS: At early follow-up, no difference was measured in revision rates, need for subsequent procedures, or RLLs between groups.

Using Illness Rating Systems to Predict Discharge Location Following Total Knee Arthroplasty

PURPOSE: Total knee arthroplasty (TKA) is increasing in frequency and cost. Optimization of discharge location may reduce total expenditure while maximizing patient outcomes. Although preoperative illness rating systems—including the American Society for Anesthesiologists Physical Classification System (ASA), severity of illness scoring system (SOI), and Mallampati rating scale (MP)—are associated with patient morbidity and mortality, their predictive value for discharge location, length of stay (LOS), and total costs remains unclear. MATERIALS AND METHODS: We conducted a retrospective analysis of 677 TKA patients (550 primary and 127 revision) treated at a single institution. The influence of ASA, SOI, and MP scores on discharge locations, LOS, and total costs was assessed using multivariable regression analyses. RESULTS: None of the systems were significant predictors of discharge location following TKA. SOI scores of major or higher (β=2.08 days, p < 0.001) and minor (β=−0.25 days, p=0.009) significantly predicted LOS relative to moderate scores. Total costs were also significantly predicted by SOI scores of major or higher (β=$6,155, p=0.022) and minor (β=−$1,163, p=0.007). CONCLUSIONS: SOI scores may be harnessed as a predictive tool for LOS and total costs following TKA, but other mechanisms are necessary to predict discharge location.

Total Knee Arthroplasty in Hemophiliacs: Gains in Range of Motion Realized beyond Twelve Months Postoperatively

BACKGROUND: Hemophiliacs have extrinsic tightness from quadriceps and flexion contractures. We sought to examine the effect of a focused physical therapy regimen geared to hemophilic total knee arthroplasty. METHODS: Twenty-four knees undergoing intensive hemophiliac-specific physical therapy after total knee arthroplasty, at an average age of 46 years, were followed to an average 50 months. RESULTS: For all patients, flexion contracture improved from -10.5 degrees preoperatively to -5.1 degrees at final follow-up (p = 0.02). Knees with preoperative flexion less than 90 degrees were compared to knees with preoperative flexion greater than 90 degrees. Patients with preoperative flexion less than 90 degrees experienced improved flexion (p = 0.02), along with improved arc range of motion (ROM) and decreased flexion contracture. For those patients with specific twelve-month and final follow-up data points, there was a significant gain in flexion between twelve months and final follow-up (p = 0.02). CONCLUSIONS: Hemophiliacs with the poorest flexion benefited most from focused quadriceps stretching to a more functional length, with gains not usually seen in the osteoarthritic population. This data may challenge traditional views that ROM gains are not expected beyond 12-18 months.