Accurate component positioning and planning is vital to prevent malalignment of total knee arthroplasty (TKA) as malalignment is associated with an increased rate of polyethylene wear and revision arthroplasty. The MAKO total knee robotic arm-assisted surgery (Stryker, Kalamazoo, MI) uses a preoperative computed tomography scan of the patient's knee and three-dimensional planning to size and orientate implants prior to bone resection. The aim of this study was to determine the accuracy of the MAKO Total Knee system in achieving the preoperative plan for bone resection and final limb coronal alignment. A series of 45 consecutive cases was performed using the MAKO Total Knee system and Triathlon Total Knee implant (Stryker) between April 2018 and May 2019. The difference between what was planned and what was achieved for bone resection and coronal limb alignment was calculated. A total of 37 patients had their data captured using the MAKO system software. Mean difference from the plan for distal femoral cuts was 0.38mm (0.32) deep/proud, anterior femoral cuts 0.44mm (0.27) deep/proud and tibial cuts 0.37mm (0.30) deep/proud. In total, 99 out of 105 (94.29%) of bone resections were within 1mm of the plan. Mean absolute difference in final limb coronal alignment was 0.78° (0.78), with 78.13% being ≤1.00° of the plan, and 100% being ≤3.00° of the plan. The accuracy in achieving preoperatively planned bone resection and final limb coronal alignment using the MAKO Total Knee system is high. Future research is planned to look at whether this is associated with decreased rates of polyethylene wear and revision arthroplasty.

Background: The aim of this study is to compare metrics specific for stressinduced hyperglycemia (SIH) with glucose for predicting ischemic stroke outcome.Methods: This observational retrospective study (n = 300) included patients acutely hospitalized for ischemic stroke over a 3.8-year period. We assessed the association between acute ischemic stroke outcome with the stress hyperglycemia ratio (SHR, relative increase in glycemia) and glycemic gap (GG, absolute increase in glycemia) using admission values and 5-day maximum values, along with incidence of poor outcome above recognized clinical thresholds of glucose 10 mmol/L, SHR 1.14, and GG 2.5 mmol/L.Results: At admission, only SHR was associated with outcome after adjustment for clinical covariates (odds ratio [OR] = 2.88; 95% CI: 1.05-7.91; P = .041), while glucose or GG were not. Admission SHR ≥ 1.14 was also an indicator of poor outcome (39.1% vs 23.4%, P = .016), but not glucose ≥10 mmol/L or GG ≥ 2.5 mmol/L. All 5-day maximum glucose metrics were associated with outcome, as was any SHR ≥ 1.14 (40.9% vs 20.1%, P < .001) or GG ≥ 2.5 mmol/L (42.9% vs 23.4%, P = .011), but not glucose ≥10 mmol/L.Increased comorbidity was strongly associated with worse outcome (P < .001) in all models.Conclusions: SHR provided the best prognostic insight at admission to assess the relationship between SIH and ischemic stroke outcome. Absolute glucose levels failed to account for natural interpatient variation in background glycemia and provided little prognostic insight. To assess the impact of SIH, future interventional studies need to be designed using designated markers of SIH such as SHR in preference to absolute glucose.

Robotic-assisted technology in total knee arthroplasty (TKA) aims to increase implantation accuracy, with real-time data being used to estimate intraoperative component alignment. Postoperatively, Perth computed tomography (CT) protocol is a valid measurement technique in determining both femoral and tibial component alignments. The aim of this study was to evaluate the accuracy of intraoperative component alignment by robotic-assisted TKA through CT validation. A total of 33 patients underwent TKA using the MAKO robotic-assisted TKA system. Intraoperative measurements of both femoral and tibial component placements, as well as limb alignment as determined by the MAKO software were recorded. Independent postoperative Perth CT protocol was obtained (n = 29) and compared with intraoperative values. Mean absolute difference between intraoperative and postoperative measurements for the femoral component were 1.17 degrees (1.10) in the coronal plane, 1.79 degrees (1.12) in the sagittal plane, and 1.90 degrees (1.88) in the transverse plane. Mean absolute difference between intraoperative and postoperative measurements for the tibial component were 1.03 degrees (0.76) in the coronal plane and 1.78 degrees (1.20) in the sagittal plane. Mean absolute difference of limb alignment was 1.29 degrees (1.25), with 93.10% of measurements ≤3 degrees of postoperative CT measurements. Overall, intraoperatively measured component alignment as estimated by the MAKO robotic-assisted TKA system is comparable to CT-based measurements.

No abstract

Chronic prosthetic joint infection (PJI) is a leading cause of failure for total joint arthroplasty. Historically, two-stage revision arthroplasty has been considered the gold standard approach to chronic PJI, however, emerging evidence suggests that one-stage revision arthroplasty may be underutilized. To our knowledge, there have been no previously published guidelines for the surgical management of chronic PJI in Australia, resulting in significant heterogeneity in management within and across centers. We aim to review contemporary concepts in the surgical management of PJI and develop an evidence-based algorithm to optimize the management of chronic hip and knee PJI, incorporating a multidisciplinary team (MDT) approach. A review was conducted to identify existing articles discussing surgical management of chronic PJI, specifically contraindications to one-stage revision arthroplasty. Absolute contraindications for one-stage revision include difficulty in treating organisms, significant soft tissue compromise, and concurrent sepsis. Relative contraindications include lack of preoperative identification of organism, presence of a sinus tract, fungal infections, significant bone loss, and immunocompromise. In determining the management of patients with a relative contraindication, MDT discussion with the consideration of patient's overall local, host, and microbiological profile is necessary. Using gathered evidence, absolute and relative contraindications for one-stage revision arthroplasty were developed into an algorithm. The algorithm is designed to assist our PJI MDT in making optimized decisions when choosing between a one-stage versus two-stage approach. Ongoing follow-up is underway to determine the effect of implementing this algorithm on patient outcomes, eradication rates, and revision rates within our center.