Shoulder arthroplasty for proximal humerus fractures in the elderly: The path from Neer to Grammont.

Shoulder replacement is indicated for the surgical treatment of proximal humeral fractures in elderly patients, when severe comminution and osteoporosis jeopardize the chances of success of any fixation technique. Two different implants are available for this purpose: anatomical hemiarthroplasty (HA) and reverse total shoulder arthroplasty (RTSA). HA for fractures was popularized by Charles Neer in the '50s and for several decades remained the only reliable implant for these injuries. However, many authors reported inconsistent results with HA as a consequence of the high rate of tuberosity and rotator cuff failure. In 1987, Paul Grammont designed the first successful RTSA, which was the end result of a long thought process on functional surgery of the shoulder. This implant was initially used to treat cuff tear arthropathy and shoulder pseudoparalysis, but indications have gradually expanded with time. Since RTSA does not rely on a functional cuff for shoulder elevation, it was felt that results in fractures could be improved by this prosthesis. In this study, the salient features of these implants are described to understand the rationale behind both approaches and highlight their pros and cons. Several clinical studies comparing HA vs RTSA for proximal humeral fractures have been published during the last two decades. A literature review is carried out to analyze and compare outcomes of both implants, analyzing clinical results, radiographic findings and complications. The final goal is to provide an overview of the different factors to consider for making a choice between these two prostheses.

3D printing in shoulder surgery.

Three-dimensional (3D) printing is a novel modality with the potential to make a huge impact in the surgical field. The aim of this paper is to provide an overview on the current use of 3D printing in shoulder surgery. We have reviewed the use of this new method in 3 fields of shoulder surgery: shoulder arthroplasty, recurrent shoulder instability and orthopedic shoulder traumatology. In shoulder arthroplasty, several authors have shown that the use of the 3D printer improves the positioning of the glenoid component, even if longer clinical follow-up is needed to determine whether the cost of this system rationalizes the potential improved functional outcomes and decreases glenoid revision rates. In the treatment of anterior shoulder instability, the literature agrees on the fact that the use of the 3D printing can: enhance the dept and size of bony lesions, allowing a patient tailored surgical planning and potentially reducing operative times; allow the production of personalized implants to restore substantial bone loss; restore glenohumeral morphology and instability. In orthopedic trauma, the use of 3D printing can be helpful to increase the understanding of fracture patterns, facilitating a more personalized planning, and can be used for resident training and education. We can conclude the current literature regarding the use of 3D printed models in orthopedic surgery agrees finding objective improvements to preoperative planning and to the surgical procedure itself, by shortening the intraoperative time and by the possibility to develop custom-made, patient-specific surgical instruments, and it suggests that there are tangible benefits for its implementation.

The role of adipose derived stem cells in the treatment of rotator cuff tears: from basic science to clinical application.

Over the last decade, regenerative medicine has become increasingly popular throughout the scientific community. The poor healing capacity at the tendon-bone interface makes the rotator cuff an appealing target for biologic agents. Adipose derived stem cells are mesenchymal cells with the capacity for self-renewal and multipotential differentiation. They have been recently proposed, both in isolation and as adjuvants to existing surgical therapies, for the treatment of rotator cuff tears. Several studies have been carried out in this research field, starting from the biological characteristics of adipose derived stem cells, their preparation and culture, up to the application in the experimental field on animal models and on humans. The purpose of this study was to provide a state of the art about the current basic science and clinical literature for the effectiveness of adipose derived stem cells in the treatment of rotator cuff tears.