Is lower tourniquet pressure during total knee arthroplasty effective? A prospective randomized controlled trial.

BACKGROUND: Higher tourniquet pressures may be associated with an increased risk of complications. We aimed to determine (1) whether a lower tourniquet pressure [systolic blood pressure (SBP) + 120 mmHg] is as effective as conventional tourniquet pressure (SBP + 150 mmHg) in providing a bloodless surgical field and decreasing blood loss, and (2) whether lowering the tourniquet pressure decreases tourniquet-related complications compared to conventional inflation pressure. METHODS: One hundred and sixty knees in 124 patients undergoing total knee arthroplasty (TKA) were randomly allocated to either conventional (n = 80) or lower inflation pressure group (n = 80). The quality of the initial surgical field and occurrence of intraoperative blood oozing, hemoglobin drop, drained volume and calculated blood loss were assessed as efficacy variables. Safety outcome variables included post-operative pain, tourniquet site skin problems (ecchymosis, bullae, skin necrosis), and other tourniquet-related complications such as nerve palsy, venous thromboembolism, and delayed rehabilitation. RESULTS: A comparable bloodless surgical field was successfully provided in both groups (100% vs. 99%, p = 1.000). One case in the conventional pressure group and two cases in the lower pressure group showed intraoperative blood oozing (p = 1.000), which was successfully controlled after an increase of 30 mmHg in the tourniquet inflation pressure. There was no difference in the hemoglobin drop, drained volume, and calculated blood loss. The two groups did not differ in any safety outcomes such as post-operative pain, thigh complications, and other tourniquet related complications. CONCLUSION: This study demonstrates that a tourniquet inflation pressure of 120 mmHg above the SBP is effective method during TKA. TRIAL REGISTRATION: The trial was with ClinicalTrials.gov ( NCT01993758 ) on November 25, 2013.

After early release of tourniquet in total knee arthroplasty, should it be reinflated or kept deflated? A randomized trial.

PURPOSE: This study was undertaken to determine the efficacy of reinflation of the tourniquet after its early release in TKA compared to early release alone, in terms of surgical field visualization and operative time. We also questioned whether tourniquet reinflation after its early release is safe, with respect to post-operative blood loss, post-operative pain and other tourniquet-related complications. METHODS: Two hundred and six patients undergoing TKA were randomly allocated to either the early release (deflation) group (n = 105) or reinflation after early release (reinflation) group (n = 101). Efficacy was measured in terms of surgical field visualization, specifically the number of wound clearances, and operative time. Safety outcomes were drained volume, decline in haemoglobin on post-operative days 2 and 5, the frequency of transfusion, knee and thigh pain visual analog scale, local wound complications, tourniquet site complications and other complications, including infection, deep vein thrombosis and pulmonary embolism. RESULTS: Surgical field visualization was better in the reinflation group; however, the operative time did not differ between the two groups. There were no differences between the two groups in post-operative blood loss, decline in haemoglobin on days 2 and 5, transfusion rate, pain level, local complications and other complications. CONCLUSION: Reinflation of tourniquet is a safe alternative to its early release after deflation in that it improves surgical field visualization during TKA. LEVEL OF EVIDENCE: Therapeutic study, Level I.

Bibliometric Analysis of Orthopedic Literature on Total Knee Arthroplasty in Asian Countries: A 10-year Analysis.

PURPOSE: We aimed to determine the quantity and quality of research output of selected Asian countries in the field of total knee arthroplasty (TKA) in the last 10 years. MATERIALS AND METHODS: Top 15 Asian countries were selected according to their gross domestic product. The Science Citation Index Expanded database was used to search for the literature published between 2004 and 2013 using "Total Knee Arthroplasty". The numbers of articles, journals and citations and the contribution of each country were analyzed. The articles were classified according to the type of study and the relative proportion of each type was analyzed. RESULTS: Asian surgeons have increasingly contributed to orthopedic literature on TKA for the past 10 years, but the dominant contribution came from only a few countries. The total number of articles published by Asian countries increased by 261%, with Japan producing most of the studies and China showing the maximum growth rate. The majority of studies were published in low impact factor journals. Korea published the highest proportion of articles in high impact factor journals. Clinical papers were most frequent. CONCLUSIONS: Our identification of research productivity pertaining to TKA among Asian countries gives a unique insight into the level of academic research in the field of TKA in these countries. There is a need to improve the quality of research to enhance the publishing power in high impact journals as well as the need for more basic research and epidemiological studies considering the unique differences among Asian patients undergoing TKA.

Do glycemic markers predict occurrence of complications after total knee arthroplasty in patients with diabetes?

BACKGROUND: Patients with diabetes have increased risk of infections and wound complications after total knee arthroplasty (TKA). Glycemic markers identifying patients at risk for complications after TKA have not yet been elucidated. QUESTIONS/PURPOSES: We aimed to determine the correlations among four commonly used glycemic markers and to identify the glycemic markers most strongly associated with the occurrence of surgical site infections and postoperative wound complications in patients with diabetes mellitus after undergoing TKA. METHODS: Our retrospective study included 462 patients with diabetes, who underwent a total of 714 TKAs. Blood levels of glycemic markers, including preoperative fasting blood glucose (FBG), postprandial glucose (PPG2), glycated hemoglobin (HbA1c), and levels obtained from random glucose testing on postoperative days 2, 5, and 14, were collected on all patients as part of a medical clearance program and an established clinical pathway for patients with diabetes at our center. Complete followup was available on 93% (462 of 495) of the patients. Correlations among markers were assessed. Associations between the markers and patient development of complications were analyzed using multivariate regression analyses of relevant cutoff values. We considered any of the following as complications potentially related to diabetes, and these were considered study endpoints: surgical site infection (superficial and deep) and wound complications (drainage, hemarthrosis, skin necrosis, and dehiscence). During the period of study, there were no fixed criteria applied to what levels of glycemic control patients with diabetes needed to achieve before undergoing arthroplasty, and there were wide ranges in the levels of all glycemic markers; for example, whereas the mean HbA1c level was 7%, the range was 5% to 11.3%. RESULTS: There were positive correlations among the levels of the four glycemic markers; the strongest correlation was found between the preoperative HbA1c and PPG2 levels (R = 0.502, p < 0.001). After controlling for potential confounding variables using multivariate analysis, the HbA1c cutoff level of 8 (odds ratio [OR], 6.1; 95% confidence interval [CI], 1.6-23.4; p = 0.008) and FBG 200 mg/dL or higher (OR, 9.2; 95% CI, 2.2-38.2; p = 0.038) were associated with superficial surgical site infection after TKA. CONCLUSIONS: In general, there is a positive correlation among the various available glycemic markers among patients with diabetes undergoing TKA, and patients undergoing surgery with HbA1c ≥ 8 and/or FBG ≥ 200 mg/dL were associated with superficial surgical site infection. These findings should be considered in patient selection and preoperative counseling for patients with diabetes undergoing TKA. LEVEL OF EVIDENCE: Level III, prognostic study.

Prevalence and predictors of post-operative coronal alignment outliers and their association with the functional outcomes in navigated total knee arthroplasty.

We aimed to determine the prevalence and predictors for being an outlier after navigated TKA and asked whether navigated TKAs with perfect coronal alignment have better functional outcomes than those without it. Alignment was measured in 124 patients (191 knees) with navigated TKAs who were available for 1year functional outcome assessment. The outcomes were compared among the 3 subgroups divided by the deviation of mechanical axis from neutral (0°): the perfect, 0° or within 1°; the acceptable, 1°-3°; and the outlier, beyond 3°. The prevalence of outliers was 20.4%, and the severity of preoperative varus deformity was the strongest predictor. Accuracy of coronal alignment in radiographs did not correlate consistently with functional outcomes.