COVID-19 and a novel initiative to improve safety by 3D printing personal protective equipment parts from computed tomography.

BACKGROUND: Powered air-purifying respirators are in short supply and can break down with extended use. Replacement parts can become hard to acquire. The aim of this study was to create an innovative quality improvement proof of concept using rapid prototyping. METHODS: Here we report three cases of 3D printed powered air-purifying respirator parts. 3D printing was performed on all parts using fused deposition modeling with standard polylactic acid, in the same way that presurgical models would be created. Measurements using an electronic caliper as well as CT scans were used to compare an original part to its corresponding 3D printed parts for accuracy. RESULTS: Electronic caliper and computed tomography measurements both showed accuracy consistant with current published norms. CONCLUSIONS: Ultimately, there will be questions surrounding intellectual property, effectiveness and potential long-term safety for these types of 3D printed parts. Future research should look into the addition of specific nanoparticles from the position of cost, efficacy, safety and improved accuracy.

Vacuum assist glenoid fixation: does this technique lead to a more durable glenoid component?

INTRODUCTION: This was a prospective random study to determine if suction applied to the glenoid vault through the coracoid process would facilitate deeper penetration of cement into the vault, and if deeper penetration would lead to a more durable glenoid component. MATERIALS AND METHODS: A group of 96 patients were randomly assigned to 1 of 2 pathways for glenoid fixation. One was cemented using modern "third generation" cementing techniques, while the second group utilizes these same steps as well as a vacuum assist (weep-hole) technique. We measured the "amount" of cement that penetrated the vault around either a pegged or keeled component as a function of the area of the cement noted on the fluoroscopic AP film that was taken 35.1 months postoperatively. We were able to determine the area of this irregular shape by using a program that was specifically written for the study. The films were evaluated by the senior author, as well as 2 musculoskeletal trained radiologists blind to the technique. RESULTS: The area of the cement mantle was found to be significantly larger (P < .005) in the group with the vacuum assist technique. There was a positive relationship between the durability of the cement mantle as determined by the presence and the extent of radiolucent lines and the size of the cement mantle (P < .001). CONCLUSION: If a cement technique is chosen to implant a glenoid component, the vacuum assist weep-hole technique is the most effective cementing technique to achieve durable fixation.