Purpose Over the last decade, robotic TKA gained popularity for improving the accuracy of implant positioning and reducing outliers in limb alignment comparing to conventional jig-based TKA. Hypothesis of this study was that this newly designed robotically assisted system will achieve a high level of accuracy for bone resection. Purpose of the study was to evaluate the accuracy of the system. Methods For this study, 75 knees in 75 patients were operated using a new, robotic system (ROSA ® Knee System; Zimmer Biomet, Warsaw, IN) with a Posterior Stabilized Total Knee Arthroplasty (Persona ® Knee System). The planned, validated and measured angles and cuts for the distal and posterior femur, for the proximal tibia and for the final coronal alignment on long standing x-rays were compared. Results A statistically significant difference was found only between the average planned and the average validated angle for femoral flexion, tibial coronal axis, medial and lateral cuts; the average difference was in any case below 1 mm or under 1 degree with SD < 1. No statistical difference was found between planned validated and measured cuts. Average difference between planned HKA and measured was 1.2 ± 1.1. No statistically significant difference was found. Conclusions The results of this study demonstrated that using this new surgical robot in total knee arthroplasty it is possible to perform accurate bone cuts and to achieve the planned angles and resections.

Background Proximal humeral fracture is the third most common fracture in elderly people after fractures of proximal femur and distal radius. They typically occur after low-energy trauma in women affected by osteoporosis, bilateral involvement is rare and usually with a simple pattern of fracture. Bilateral four-part proximal humerus fractures are even less frequent, with only a few reports published previously, with all of them caused by a seizure or electrocution in patients < 65 years old. Case presentation We present a 77-year-old right-handed female that sustained a bilateral simultaneous four-part humeral fracture secondary to accidental slip-and-fall occurred at home. Patient was treated with simultaneous bilateral Reverse Shoulder Arthroplasty (RSA) in our structure. Functional assessment was undertaken at 6- and 12-months follow-up (FU) after surgery, using the Constant-Murley score (CMS) and the Disabilities of the Arm, Shoulder and Hand (DASH) score. Outcome The simultaneous RSA procedure was well tolerated by the patient. Post-operative course was optimal with relatively low blood loss, rapid functional recovery, and fast pain relief. The CMS and DASH score were reasonably good at 6-months FU (right-left: 39–57 and 50.8–30.5, respectively) and they further improved at 1-year FU (right-left: 66–82 and 35.8–19.2, respectively). X-rays showed good position of the implants with no evidence of scapular notching at 1 year. Patient rated the overall satisfaction as good. Discussion Bilateral four-part proximal humeral fractures are complex injuries difficult to manage. Optimal treatment is controversial, and it can be conservative or surgical, varying from open reduction and internal fixation (ORIF) to arthroplasty. However, this last option is still directed to only one side, preferring ORIF or conservative treatment for the contralateral. In case of comminute and displaced fractures, low bone quality, rotator cuff deficiencies and eccentric osteoarthritis, RSA is to prefer as a surgical option. For these reason, in selected cases of bilateral four parts proximal humerus fracture, especially when occurs in elderly patients, the simultaneous RSA implantation can represent a valid option to achieve an adequate functional result and a fast recovery. This is the first description, to our knowledge, in English literature of a simultaneous bilateral RSA.

Introduction: There have been reported adverse reactions in patients with large head metal-on-metal hip arthroplasty, therefore metal particle debris are a cause for concern. The aim of this study was to evaluate the release trend of metal ions and the correlated variables. Methods: 54 patients were prospectively enrolled into the study from 2004 to 2006. All patients had 36-mm metal head, Pinnacle acetabular component, Summit stem and Ultamet CoCr alloy liner (Depuy Inc.), and underwent clinical and radiological management. The haematic concentration of Cr-Co at 0, 6, 12, 24, 60 and 120 months after the implantation was analysed in a sub-cohort of 34 patients. Results: 10-year revision rate for each case was 8.9%. The average concentration of Co at 120 months was 3.12 μg/L (median 2.20) with 53% values >2 μg/L and 1 >7 μg/L. After 6 months the median levels of Cr and Co were higher than time 0 (p < 0.0001); no significant differences were found between 6 and 24 months; while Co had significant increase between 60 and 120 months (p = 0.002). Overweight, University of California at Los Angeles (UCLA) >9 and <50 years old patients have significantly higher circulating metal ions. Discussion: This is 1 of the few prospective studies on the argument. The revision rate is conforming to records. Our data shows ionic concentration is not predictive of revision or adverse reaction to metals. We described a 3-phase trend for Co probably due to the loss of integrity of the surfaces.

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