Self-aligned Technique for Tibial Component Placement in Total Knee Arthroplasty Lessening Rotational Malalignment in Measured Resection and Gap-Balancing Techniques

Background@#Femorotibial rotational mismatch can occur when there is a rotational malalignment in either the tibial or femoral component. Self-aligned technique was proposed for orienting the tibial component in relation to the femoral prosthesis to reduce rotational malalignment between components. Therefore, we aimed to compare the rotational angle of the femoral and tibial components, as well as the femorotibial rotational mismatch, between the measured resection (MR) and gap-balancing (GB) techniques when combined with a self-aligned technique. @*Methods@#We conducted a nonrandomized, experimental study with 50 patients in each group. The femoral rotation was set to 3° external rotation relative to the posterior condylar axis in the MR group, whereas the femur was resected to obtain an optimal rectangular flexion gap in the GB group. The self-aligned method was used to set the tibial rotation in both groups. Femoral and tibial rotational alignments were evaluated compared to a surgical transepicondylar axis of the femur using computed tomography.Rotational mismatch was defined as a difference between the femoral and tibial rotational alignments. A positive value indicated that the component was externally rotated relative to the reference line. @*Results@#The femoral component of the GB group was more externally rotated than that of the MR group (1.52° ± 1.31° vs 0.28° ± 1.16°, p < 0.001). However, the tibial rotational angle was not statistically significantly different between the MR and GB groups (1.28° ± 3.17° vs. 1.86° ± 2.81°, p = 0.220), and the rotational mismatch was 1.00° ± 3.28° and 0.34° ± 2.71°, respectively ( p = 0.306). @*Conclusions@#Although the femoral component of the GB group had a greater degree of external rotation than that of the MR group, the use of a self-aligned technique for tibial component placement resulted in no significant difference in tibial rotational alignment or rotational mismatch. This technique helps align the tibial component with the femoral component and lessen the degree of rotational malalignment in both the MR and GB techniques.

Perioperative Outcomes of Patients Who Were Not Candidates for Additional Nonsteroidal Antiinflammatory Drugs in a Multimodal Pain Control Regimen for Total Knee Arthroplasty

Background@#Postoperative pain following total knee arthroplasty (TKA) may hamper patients from a rapid recovery and increase perioperative blood loss and stress on the cardiovascular system. Therefore, our objective was to assess perioperative outcomes after TKA in patients who were not candidates for the additional nonsteroidal anti-inflammatory drugs (NSAIDs) in a multimodal pain control regimen. @*Methods@#Propensity score matching for age, sex, body mass index, American Society of Anesthesiologists class, and preoperative hemoglobin level was conducted on patients undergoing unilateral TKA, and thereby 52 patients remained in each group. The control group comprised patients who received parenteral parecoxib every 12 hours during the first 48 hours after TKA. The NoNSAIDs group did not receive NSAIDs because of known contraindications. Identical postoperative pain control including intravenous patient-controlled analgesia was applied for all patients. Visual analog scale (VAS) score for pain, knee flexion, blood loss, serum cardiac troponin-T (cTnT), and length of stay (LOS) were determined. @*Results@#The No-NSAIDs group had significantly higher VAS scores in 6–96 hours and consumed more morphine at 24 hours and 48 hours after the surgery than the control group. The No-NSAIDs group had significantly less knee flexion at 48 hours (p = 0.045) and tended to have more emesis and longer LOS than the control group. The blood loss of the No-NSAIDs and control group was 552.52 mL and 397.65 mL (p = 0.02), respectively, and blood transfusion rate was 23.1% and 17.3% (p = 0.63), respectively. The cTnT of the No-NSAIDs group rose over the first 48 hours and was significantly higher than that of the control group at 48 hours. @*Conclusions@#Patients who were not candidates for NSAIDs had significantly higher pain scores and consumed more morphine after TKA. They also tended to have greater blood loss and the rising of cardiac biomarkers during the first 48 hours after TKA.Hence, these patients may benefit from supplementary analgesia and appropriate perioperative monitoring.

Perioperative Outcomes of Patients Who Were Not Candidates for Additional Nonsteroidal Antiinflammatory Drugs in a Multimodal Pain Control Regimen for Total Knee Arthroplasty

Background@#Postoperative pain following total knee arthroplasty (TKA) may hamper patients from a rapid recovery and increase perioperative blood loss and stress on the cardiovascular system. Therefore, our objective was to assess perioperative outcomes after TKA in patients who were not candidates for the additional nonsteroidal anti-inflammatory drugs (NSAIDs) in a multimodal pain control regimen. @*Methods@#Propensity score matching for age, sex, body mass index, American Society of Anesthesiologists class, and preoperative hemoglobin level was conducted on patients undergoing unilateral TKA, and thereby 52 patients remained in each group. The control group comprised patients who received parenteral parecoxib every 12 hours during the first 48 hours after TKA. The NoNSAIDs group did not receive NSAIDs because of known contraindications. Identical postoperative pain control including intravenous patient-controlled analgesia was applied for all patients. Visual analog scale (VAS) score for pain, knee flexion, blood loss, serum cardiac troponin-T (cTnT), and length of stay (LOS) were determined. @*Results@#The No-NSAIDs group had significantly higher VAS scores in 6–96 hours and consumed more morphine at 24 hours and 48 hours after the surgery than the control group. The No-NSAIDs group had significantly less knee flexion at 48 hours (p = 0.045) and tended to have more emesis and longer LOS than the control group. The blood loss of the No-NSAIDs and control group was 552.52 mL and 397.65 mL (p = 0.02), respectively, and blood transfusion rate was 23.1% and 17.3% (p = 0.63), respectively. The cTnT of the No-NSAIDs group rose over the first 48 hours and was significantly higher than that of the control group at 48 hours. @*Conclusions@#Patients who were not candidates for NSAIDs had significantly higher pain scores and consumed more morphine after TKA. They also tended to have greater blood loss and the rising of cardiac biomarkers during the first 48 hours after TKA.Hence, these patients may benefit from supplementary analgesia and appropriate perioperative monitoring.

Contamination Rate of Burnt Necrotic Tissue after Electrocoagulation in Total Knee Arthroplasty

BACKGROUND: Periprosthetic joint infection (PJI) is one of the commonly found catastrophic complications after total knee arthroplasty (TKA). Preoperative antibiotic prophylaxis, proper skin cleansing, shortened operative time, and sterility of surgical field and equipment are essential to minimize the risk of PJI. Although bacterial contamination of electrocautery tips has been reported, contamination of residual product of electrocoagulation, burnt necrotic tissue (BNT), is not well known. Therefore, we aimed to assess the contamination rate of BNT and association between contaminated BNT and PJI, and risk factors.METHODS: BNTs from 183 patients who had undergone unilateral primary TKA at our institution were retrospectively analyzed. In each patient, three to five specimens of BNT were routinely collected in the operative field of primary TKA. Collecting time was defined as the duration from start of using the electrocautery device to the first collection of BNT.RESULTS: Culture was positive in eight of 183 patients (4.4%; contaminated BNT group), and the most commonly isolated organism was coagulase-negative Staphylococcus (62.5%). The average operative time was 103.1 ± 44.2 minutes in the contaminated BNT group and 79.0 ± 16.7 minutes in the non-contaminated BNT group (p = 0.17), and collecting time was 48.0 ± 44.3 minutes and 29.7 ± 17.0 minutes (p = 0.28), respectively. None of the patients with contaminated BNT developed PJI, whereas four patients with culture-negative BNT developed PJI within 2 postoperative years.CONCLUSIONS: BNT in surgical field can become a reservoir of contaminating bacteria. However, contamination of BNT was not associated with PJI. Therefore, routine removal of all BNTs may be unnecessary.

The Effect of Prosthesis Design on Blood Loss in Simultaneous Bilateral Total Knee Arthroplasty: Closed-Box versus Open-Box Prosthesis

BACKGROUND: Various pre- and perioperative risk factors have been reported in association with blood loss in knee arthroplasty. However, the effect of the uncovered cancellous surface on blood loss in simultaneous bilateral total knee arthroplasty (SBTKA) by different prosthetic designs is not well elucidated. Therefore, this study aimed to compare the blood loss and transfusion rate between different knee prostheses in SBTKA and to identify risk factors that influence blood loss and transfusion after SBTKA. METHODS: Demographic and perioperative data of patients who underwent SBTKA using either a closed-box or an open-box femoral component of posterior-stabilized fixed-bearing (PS FB) knee system were retrospectively reviewed. The calculated blood loss (CBL) and blood transfusion rate were compared by using Student t-test and confirmed with multivariate regression analysis. RESULTS: There was no significant difference in preoperative parameters between 54 closed-box and 56 open-box PS FB TKAs. The CBL of the closed-box TKA group was 135.23 mL less (95% confidence interval [CI], −215.30 to −55.16; p = 0.001) than that of the open-box TKA group. However, the blood transfusion rates of the closed- and open-box TKA groups were not significantly different (24.1% and 38.5%, p = 0.11). For each additional minute of total operative time, 3.75 mL (95% CI, 1.75 to 5.76; p < 0.001) of blood loss was anticipated. For each additional mg/dL of preoperative hemoglobin, 71% (p < 0.001) reduction of blood transfusion probability was predicted. CONCLUSIONS: The use of closed- and open-box knee prostheses resulted in a significant difference in blood loss in SBTKA. Prolonged operative time also significantly increased CBL. Therefore, strategies to control the bleeding surface and shorten operative duration may be considered if blood loss is of special concern. The preoperative hemoglobin was the only factor that affects the probability of blood transfusion in SBTKA.