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Background: To protect both the surgeon and patient during procedures, hooded protection shields are used during joint arthroplasty procedures. Headache, malaise, and dizziness, consistent with increased carbon dioxide (CO 2 ) exposure, have been anecdotally reported by surgeons using hoods. We hypothesized that increased CO 2 concentrations were causing reported symptoms., Methods: Six healthy subjects (4 men) donned hooded protection, fan at the highest setting. Arm cycle ergometry at workloads of 12 and 25 watts (W) simulated workloads encountered during arthroplasty. Inspired O 2 and CO 2 concentrations at the nares were continuously measured at rest, 12 W, and 25 W. At each activity level, the fan was deactivated and the times for CO 2 to reach 0.5% and 1.0% were measured., Results: At rest, inspired CO 2 was 0.14% ± 0.04%. Exercise had significant effect on CO 2 compared with rest (0.26% ± 0.08% at 12 W, P = .04; 0.31% ± 0.05% at 25 W, P = .003). Inspired CO 2 concentration increased rapidly with fan deactivation, with the time for CO 2 to increase to 0.5% and 1.0% after fan deactivation being rapid but variable (0.5%, 12 ± 9 seconds; 1%, 26 ± 15 seconds). Time for CO 2 to return below 0.5% after fan reactivation was 20 ± 37 seconds., Conclusion: During simulated joint arthroplasty, CO 2 remained within Occupational Safety and Health Administration (OSHA) standards with the fan at the highest setting. With fan deactivation, CO 2 concentration rapidly exceeds OSHA standards., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Restoration of mechanical axis in total knee arthroplasty (TKA) is correlated with improved implant survivorship. We assessed the accuracy and required surgical time using a hand-held accelerometer-based navigation system for TKA. Data collected on 53 patients included assembly, resection, and tourniquet times. Implant alignment and mechanical axis were measured on radiographs. Femoral alignment was 0.29° ± 2.2° varus. Tibial alignment was 0.09° ± 1.4° valgus. Postoperative mechanical axis was 0.2° ± 2.1° varus. Malalignment rates for the femur, tibia, and axis were 13%, 3.8%, and 17%, respectively. Average time for pinning and navigating was 3.6 minutes for the femur and 2.6 minutes for the tibia; mean tourniquet time was 62 minutes. This navigation system accurately re-established mechanical axis without increasing surgical time., (Copyright © 2015 Elsevier Inc. All rights reserved.)

This study compares the incidence of venous thromboembolic event (VTE) in 55 patients (110 knees) undergoing simultaneous bilateral TKA with 287 patients (287 knees) undergoing unilateral TKA using a mobile compression device as monotherapy prophylaxis in both groups. All patients were clinically evaluated 3months after surgery with symptomatic confirmed VTE as an endpoint. Deep venous thrombosis (DVT) was documented by duplex ultrasound and pulmonary embolism (PE) was documented by spiral CT. The simultaneous bilateral TKA group had 6 VTEs (10.9%) with 2 PEs (3.6%). The unilateral TKA group had 9 VTEs (3.1%), and 0 PE. Patients undergoing simultaneous bilateral TKA yielded more than twice the rate of VTE compared with patients undergoing unilateral TKA using a mobile compression device as sole thromboprophylactic modality., (Copyright © 2013 Elsevier Inc. All rights reserved.)

This preliminary prospective study to determine the rate of deep venous thrombosis (DVT) examined 277 patients undergoing total knee or total hip arthroplasty (TKA or THA) who were randomized to use a portable, continuous enhanced circulation therapy (CECT) compression device and low-molecular-weight heparin (LMWH) or to receive LMWH alone. Patients were screened for DVT using duplex ultrasound at hospital discharge and followed clinically for 3 months. In TKA, 5 DVTs (6.6%) occurred in the CECT + LMWH group compared with one pulmonary embolism and 14 DVTs (19.5%) in the LMWH group (P = .018). In THA, 1 DVT (1.5%) occurred in the CECT + LMWH group and 2 DVTs (3.4%) occurred in the LMWH group. This preliminary study demonstrated significant reduction in rate of DVT after TKA when the CECT device was combined with LMWH.

The early outcomes of 2 newer-generation posterior cruciate ligament-retaining fixed-bearing total knee arthroplasty (TKA) implant designs were assessed to determine if a single sagittal radius femoral design has an advantage in obtaining earlier knee range of motion and function when compared with a contemporary multiradius femoral design. Total knee arthroplasty patients were prospectively randomized to receive either a single sagittal radius femoral design (n=50) or a multiradius femoral design (n=50). Knee extensor mechanism function after TKA with either a single sagittal radius or multiradius implant was comparable in contemporary posterior cruciate ligament-retaining TKA designs.