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.

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.

Chronic shoulder impingement is one of the most common causes of shoulder pain. Intrinsic, extrinsic and secondary factors play a role in this syndrome; however the etiology of the pathology is still under debate. In rare cases, it can be caused by tumors, such as an osteochondroma. In the present study, a 49-year-old patient presented with shoulder pain for 6 months. Initially he underwent conservative treatment, without relief of symptoms. X-rays and MRI were then performed and showed the presence of an exostotic formation on the undersurface of the lateral third of the clavicle. The formation was arthroscopically removed. Histologic examination confirmed the diagnosis of osteochondroma. After surgery, the patient resumed fully activities with no symptoms within 3 months. At 1 year follow up, there are still no clinical or radiological signs of recurrence. This is, to our knowledge, the first case where an arthroscopic approach was used to remove an ostochondroma of the distal third of the clavicle.

Purpose To systematically review the outcomes of surgical treatments of chronic acromioclavicular joint dislocation. Methods Studies were identified by electronic databases (Ovid, PubMed). All studies reporting functional and radiological outcomes of surgical treatments of chronic acromioclavicular joint dislocations were included. Following data were extracted: authors and year, study design, level of evidence, number of patients, age, classification of acromioclavicular joint dislocation, time to surgery, surgical technique, follow-up, clinical and imaging outcomes, complications and failures. Descriptive statistics was used, when a data pooling was not possible. Comparable outcomes were pooled to generate summary outcomes reported as frequency-weighted values. Quality appraisal was assessed through the MINORS checklist. Results Fourty-four studies were included for a total of 1020 shoulders. Mean age of participants was 38 years. Mean followup was 32.9 months. Arthroscopic techniques showed better results than open approach (p < 0.0001). Synthetic reconstructions demonstrated better functional outcomes compared to internal fixation and biologic techniques (p < 0.0001). Among biologic techniques, combined coracoclavicular and acromioclavicular ligaments reconstruction showed better Constant (p = 0.0270) and ASES (p = 0.0113) scores compared to isolated coracoclavicular ligaments reconstruction; anatomic biologic non-augmented graft reconstruction showed better Constant (p < 0.0001), VAS (p < 0.0001) and SSV (p = 0.0177) results compared to augmented techniques. No differences in functional outcomes could be found between anatomic biologic nonaugmented graft versus synthetic reconstructions. Overall, methodological quality of the included studies was low. Conclusion Anatomic reconstructions, both synthetic and biologic, showed the best functional results. Level of evidence IV.