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

Sarah Rudasill,Jonathan R. Dattilo,Jiabin Liu,Ari Clements,Charles L. Nelson,Atul F. Kamath 대한슬관절학회 2018 대한슬관절학회지 Vol.30 No.1

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.

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

( Joshua T. Steere ),( Michael C. Sobieraj ),( Christopher J. Defrancesco ),( Craig L. Israelite ),( Charles L. Nelson ),( Atul F. Kamath ) 대한슬관절학회 2018 대한슬관절학회지 Vol.30 No.3

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 twoyear 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.

Prospective Study of Central versus Peripheral Obesity in Total Knee Arthroplasty

John G. Armstrong,Tyler R. Morris,Ronnie Sebro,Craig L. Israelite,Atul F. Kamath 대한슬관절학회 2018 대한슬관절학회지 Vol.30 No.4

Purpose: Body mass index (BMI) is often used to predict surgical difficulty in patients receiving total knee arthroplasty (TKA); however, BMI neglects variation in the central versus peripheral distribution of adipose tissue. We sought to examine whether anthropometric factors, rather than BMI alone, may serve as a more effective indication of surgical difficulty in TKA.Materials and Methods: We prospectively enrolled 67 patients undergoing primary TKA. Correlation coefficients were used to evaluate the associations of tourniquet time, a surrogate of surgical difficulty, with BMI, pre­ and intraoperative anthropometric measurements, and radiographic knee alignment. Similarly, Knee Injury and Osteoarthritis Outcome Score (KOOS) was compared to BMI.Results: Tourniquet time was significantly associated with preoperative inferior knee circumference (p=0.025) and ankle circumference (p=0.003) as well as the intraoperative depth of incision at the quadriceps (p=0.014). BMI was not significantly associated with tourniquet time or any of the radiographic parameters or KOOS scores.Conclusions: Inferior knee circumference, ankle circumference, and depth of incision at the quadriceps (measures of peripheral obesity) are likely better predictors of surgical difficulty than BMI. Further study of alternative surgical indicators should investigate patients that may be deterred from TKA for high BMI, despite relatively low peripheral obesity.

Saline-Coupled Bipolar Sealing in Simultaneous Bilateral Total Knee Arthroplasty

Atul F. Kamath,Daniel C. Austin,Peter B. Derman,R. Carter Clement,Jonathan P. Garino,Gwo-Chin Lee 대한정형외과학회 2014 Clinics in Orthopedic Surgery Vol.6 No.3

Background: The efficacy of saline-coupled bipolar sealing devices in joint arthroplasty is uncertain, and the utility in simultaneous bilateral total knee arthroplasty (TKA) has not been reported. Methods: This study compares the use of bipolar sealing and conventional electrocautery in 71 consecutive patients. The experimental and control groups were matched for age, sex, body mass index, American Society of Anesthesiologists (ASA) classification, and preoperative hemoglobin. Variables of interest included blood loss, transfusion requirements, and operative characteristics. Results: In comparison to patients treated with conventional electrocautery, those treated with the bipolar sealer were 35% less likely to require transfusion. The median number of transfusions per case was also significantly lower in the experimental group. Hemoglobin change, total blood loss, and length of stay were not significantly different between the groups. The experimental group had longer operative times. Conclusions: Bipolar sealing shows promise as a blood loss reduction tool in simultaneous bilateral TKA. The marginal savings attributed to reduced transfusion rates with use of the bipolar sealer did not exceed the additional per-case expense of using the device. The decision to use the device with the goal of less blood loss must come with the additional expense associated with its use.

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

Atul F. Kamath,John G. Horneff,Angela Forsyth,Valdet Nikci,Charles L. Nelson 대한정형외과학회 2012 Clinics in Orthopedic Surgery Vol.4 No.2

Background: Hemophiliacs have extrinsic tightness from quadriceps and fl exion contractures. We sought to examine the effectof a focused physical therapy regimen geared to hemophilic total knee arthroplasty. Methods: Twenty-four knees undergoing intensive hemophiliac-specifi c physical therapy after total knee arthroplasty, at an averageage of 46 years, were followed to an average 50 months. Results: For all patients, fl exion contracture improved from −10.5 degrees preoperatively to −5.1 degrees at fi nal follow-up (p =0.02). Knees with preoperative fl exion less than 90 degrees were compared to knees with preoperative fl exion greater than 90degrees. Patients with preoperative fl exion less than 90 degrees experienced improved fl exion (p = 0.02), along with improved arcrange of motion (ROM) and decreased fl exion contracture. For those patients with specifi c twelve-month and fi nal follow-up datapoints, there was a signifi cant gain in fl exion between twelve months and fi nal follow-up (p = 0.02). Conclusions: Hemophiliacs with the poorest fl exion benefi ted most from focused quadriceps stretching to a more functionallength, with gains not usually seen in the osteoarthritic population. This data may challenge traditional views that ROM gains arenot expected beyond 12-18 months.

Blood Transfusion Rates as a Primary Outcome Measure: The Use of Predetermined Triggers and Display of Clinical Indications in Providing Accurate Comparative Transfusion Rates: In Reply

Atul F. Kamath,Daniel C. Austin,Peter B. Derman,R. Carter Clement,Jonathan P. Garino,Gwo-Chin Lee 대한정형외과학회 2017 Clinics in Orthopedic Surgery Vol.9 No.1

We thank the readers for their letter to the editor, and for interest in our manuscript published in 2014. Issues surrounding blood management continue to be an important part of the global care of total joint arthroplasty patients as we move into 2017. In addition to our group’s multiple studies on the use of bipolar sealing devices in joint arthroplasty, 1,2) we continue to examine our blood management and transfusion practices. We now routinely employ the use of tranexamic acid, which has further allowed a reduction in transfusion requirements. This may account for some of the differences between contemporary rates of transfusion, and historical rates presented before the routine use of tranexamic acid. We thank the readers for inquiring about the transfusion reduction rates as presented in our manuscript. The absolute reduction in transfusion rate was 83% to 55%, a difference of 28% points. The relative reduction as a percentage of the original transfusion rate of 83% would be approximately 35%. In a simpler comparison, for example, if the transfusion rate was reduced from 10% to 5%, we would have stated that there was an absolute reduction of 5% but a 50% reduction from the baseline rate (5%/10% = 0.5). In our manuscript, we acknowledge some of the limitations discussed by the readers’ letter to the editor. This study was not a prospective randomized controlled trial, and therefore issues of blinding and randomization do not apply. Rather, our study has important applications for real-world transfusion scenarios based on clinical scenario and patient comorbid conditions. We thank the readers for sharing their own data and algorithm for management, which, like our practice, involves careful evaluation of “comorbidity and cardiorespiratory risk, ongoing blood loss, and symptoms related to anaemia.” Likewise, confounders of age and dilutional anaemia are important considerations in any study of blood management, but are not controlled for in our clinical practice review. Again, we thank the readers for their letter to the editor, as well as their own institutional efforts to examine transfusion thresholds, understand adjunctive tools in blood management, and further the perioperative care of total joint patients.

Preoperative Serum Albumin Levels Predict Treatment Cost in Total Hip and Knee Arthroplasty

Sarah E. Rudasill,Andrew Ng, BS,Atul F. Kamath 대한정형외과학회 2018 Clinics in Orthopedic Surgery Vol.10 No.4

Background: Hypoalbuminemia (serum albumin < 3.5 g/dL) is associated with increased morbidity and mortality in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). However, costs associated with hypoalbuminemia remain unknown. This study investigated the effect of serum albumin on direct treatment costs, length of stay (LOS), and readmissions for primary and revision THA and TKA patients. Methods: All adult patients at a single institution undergoing primary or revision THA or TKA between January 2014 and December 2016 were retrospectively reviewed. Patients were stratified by preoperative serum albumin level. The primary outcome was total direct costs at index hospitalization. Secondary outcomes included LOS and readmission within 30 days. Multivariable regressions were utilized to adjust for demographics and comorbidities. Results: Of 3,785 patients, 114 (3.0%) had hypoalbuminemia. After adjustment, hypoalbuminemia was associated with a 16.2% increase in costs (β = 0.162; 95% confidence interval [CI], 0.112 to 0.213; p < 0.001), representing an average cost increase of $3,383 (95% CI, $2,281 to $4,485) relative to costs for serum albumin > 4.5 g/dL. The increased total costs were significantly higher in revision ($4,322, p = 0.034) than in primary ($3,446, p < 0.001) procedures. In adjusted regression, each 1.0 g/dL increase in serum albumin yielded a 6.6% reduction in costs (β = –0.066; 95% CI, –0.090 to –0.042]; p < 0.001), for average savings of $1,282 (95% CI, $759 to $1,806) per unit albumin. Adjusted regressions demonstrated that a 1-point increase in serum albumin reduced readmissions by 53% (odds ratio, 0.47; 95% CI, 0.31–0.73; p = 0.001) and LOS by 0.6 days (β = –0.60; 95% CI, –0.76 to –0.44; p < 0.001). Conclusions: Hypoalbuminemia is associated with increased total direct costs, LOS, and readmissions following primary and revision THA and TKA. Future efforts to predict and address total costs should take into consideration the patient's preoperative serum albumin levels.