Preoperative Postvoid Residual Is Not Predictive of Postoperative Urinary Retention in Primary Total Joint Arthroplasty Patients.

Background: Postoperative urinary retention is a common complication after total hip and knee arthroplasty. Postvoid residual (PVR) scanning is a noninvasive method commonly used to evaluate this complication. Preoperatively increased PVR (PrePVR) has been suggested as a risk factor for postoperative catheterization. The aim of this study was to prospectively assess the importance of PrePVR and its relationship with urinary catheter placement, urology consult, and length of stay postoperatively. Methods: Data was prospectively and consecutively collected at a single institution. All patients were bladder scanned preoperatively to collect PrePVR and subsequently scanned on postoperative days zero and one to collect Postoperative PVR. Chart review was performed to determine the number of straight catheterizations, Foley placement, urology consult and length of stay as well as patient demographics. Results: Ninety-four consecutive patients were included in this study. There was a significantly increased postoperative PVR as compared to PrePVR (48.0 mL vs 21.0 mL; P < .0001). A PrePVR >50 mL was not associated with a significant difference in PVR between before and after surgery (P = .13); length of stay (P = .08); need for straight catheterization (P = .11); postoperative Foley placement (P = 1.0); or urology consult (P = 1.0). The only significant risk factor identified for postoperative Foley catheter placement was age (77.7 vs 64.2; P = .02). Conclusions: PrePVR >50 mL was not an accurate predictor of postoperative urinary retention after total joint arthroplasty. PVR significantly increased in all patients. Male sex and increasing age were associated with large increases in PVR postoperatively and an increased risk of catheterization.

State-of-the-Art Review on Wearable Obstacle Detection Systems Developed for Assistive Technologies and Footwear.

Walking independently is essential to maintaining our quality of life but safe locomotion depends on perceiving hazards in the everyday environment. To address this problem, there is an increasing focus on developing assistive technologies that can alert the user to the risk destabilizing foot contact with either the ground or obstacles, leading to a fall. Shoe-mounted sensor systems designed to monitor foot-obstacle interaction are being employed to identify tripping risk and provide corrective feedback. Advances in smart wearable technologies, integrating motion sensors with machine learning algorithms, has led to developments in shoe-mounted obstacle detection. The focus of this review is gait-assisting wearable sensors and hazard detection for pedestrians. This literature represents a research front that is critically important in paving the way towards practical, low-cost, wearable devices that can make walking safer and reduce the increasing financial and human costs of fall injuries.

Infections following rejection therapies in kidney and liver transplant recipients.

INTRODUCTION: Infections are known complications of solid-organ transplant. Treatment for rejection may increase risk of infection. We aimed to study frequency of infection and identify the risk factors for infections in solid organ transplant (SOT) (liver and kidney) recipients treated for rejection. METHODS: This is a retrospective chart review of all liver and kidney transplant recipients treated for rejection at our institution from 2014 to 2020. We collected information on episodes of acute rejection in the first year of transplant and infections within 6 months following rejection treatment. RESULTS: We identified 257 transplant patients treated for rejection. One hundred twelve (43.6%) developed infections, with a total of 226 infections. Urinary tracts infections were the most common, 72 (31.9%), followed by cytomegalovirus viremia in 37 (16.4%), bacteremia in 24 (10.6%), and BK virus in 14 (6.2%). Female sex (p = .047), elevated neutrophil count at rejection (p = .002), and increased number of rejection episodes (p = .022) were predictors of infection in kidney and simultaneous liver-kidney recipients. No specific type of induction or rejection therapy was identified as a risk factor for infection, likely due to the prophylaxis protocols at our institution. Infection post rejection treatment was associated with higher graft loss (p = .021) and mortality (p = .031) in kidney transplant recipients. CONCLUSIONS: Infections are common complications after treatment of SOT rejection. Female gender, higher neutrophil at time of rejection, and increased numbers of rejection episodes were predictors of infections after rejection in simultaneous liver-kidney and kidney transplant patients. Infections were predictors of graft loss at 6 months and mortality at any point in follow-up in kidney transplant patients.

Application of Wearable Sensors in Actuation and Control of Powered Ankle Exoskeletons: A Comprehensive Review.

Powered ankle exoskeletons (PAEs) are robotic devices developed for gait assistance, rehabilitation, and augmentation. To fulfil their purposes, PAEs vastly rely heavily on their sensor systems. Human-machine interface sensors collect the biomechanical signals from the human user to inform the higher level of the control hierarchy about the user's locomotion intention and requirement, whereas machine-machine interface sensors monitor the output of the actuation unit to ensure precise tracking of the high-level control commands via the low-level control scheme. The current article aims to provide a comprehensive review of how wearable sensor technology has contributed to the actuation and control of the PAEs developed over the past two decades. The control schemes and actuation principles employed in the reviewed PAEs, as well as their interaction with the integrated sensor systems, are investigated in this review. Further, the role of wearable sensors in overcoming the main challenges in developing fully autonomous portable PAEs is discussed. Finally, a brief discussion on how the recent technology advancements in wearable sensors, including environment-machine interface sensors, could promote the future generation of fully autonomous portable PAEs is provided.

Robotic-Assisted Total Knee Arthroplasty Allows for Trainee Involvement and Teaching Without Lengthening Operative Time.

BACKGROUND: Robot-assisted total knee arthroplasty (RA-TKA) is more accurate than mechanical total knee arthroplasty (M-TKA) and can provide real-time feedback about alignment and soft-tissue balancing that may be helpful in trainee education. However, both robotic-assist and trainee involvement potentially increase the surgical time. This study sought to evaluate whether RA-TKA procedures were longer than M-TKA procedures and whether trainee participation added additional surgical time. METHODS: This retrospective cohort study reviewed 220 consecutive primary TKAs (110 M-TKA and 110 RA-TKA) performed by an orthopedic trainee under supervision or performed by the consultant surgeon with an assistant present. For M-TKAs, a measured resection technique was used. For all RA-TKAs, the MAKO robotic system (Stryker, USA) was used. Tourniquet time was measured from inflation immediately prior to skin incision to deflation after placement of the final polyethylene insert. Procedures performed by a consulting surgeon with a surgical assist were used as controls for procedures performed by the trainee. In trainee-conducted procedures, the trainee is responsible for performing all critical aspects of the procedure while the consulting surgeon provides supervision and acts as first assist. RESULTS: 103 M-TKA and 96 RA-TKA were included. Tourniquet time was significantly longer for RA-TKAs vs M-TKAs (100 vs 89 minutes, P < .0001). However, there were no significant differences in tourniquet times between surgery performed by a trainee vs the consulting surgeon with surgical assist for either M-TKA (P = .3452) or RA-TKA (P = .6724). CONCLUSIONS: While RA-TKA takes longer, orthopedic trainees do not add additional time. Trainees at all stages of postgraduate learning can be educated in the use of robotic technology and potentially benefit from real-time feedback without further compromising surgical efficiency or increasing patient risk.