Four themes were emphasized in the year 2020, including new perspectives in knee arthroplasty surgery, contribution of 3D metal printing in developing implants for sarcoma surgery, usefulness of lateralization of the rotation center in reverse prosthetic shoulder surgery, and, lastly, contribution of microsurgery in bone defects. Nevertheless, 20% of patients still experience an unsatisfactory outcome following knee arthroplasty. Advances in tribology and implant fixation have rendered it possible to deviate from a purely mechanical approach and develop new resurfacing strategies that respect the patient's native anatomy. These advances are aimed at a kinematic alignment that is capable of recreating the natural joint movement with its ligament balance. This has resulted in developing personalized implants and ultra-precise positioning techniques, which are assisted by navigation and robot.

In oncological surgery, certain tumor resections are associated with difficult reconstructions, especially within the pelvis, as these resections are accompanied by a high rate of complications and mechanical failures. Metal 3D printing technology has rendered it possible to design porous titanium implants, which basically mirror the substance loss. Their stable fixation can already been anticipated at the design stage, thereby facilitating the reconstruction process and offering lasting mechanical perspectives. The performance of a reverse shoulder arthroplasty, which is indicated in osteoarthritis associated with a cuff tear, results in a medialization of the glenohumeral rotation center. This medialization results in a conflict with the scapula and progressive loosening of joint replacement. Metallic augmentation or bone grafting techniques enable lateralization of the rotation center, thereby preventing these complications.

Finally, when facing vast bone-tissue defects with a significant functional impact, the use of autologous vascularized grafts of different types represents a surgical solution that is still constantly evolving, including the recent contribution of super microsurgery.

The 2020 annual meeting of the American Society of Hematology (ASH) provided us with several contributions to the field of hematopoietic stem cell transplantation (HSCT). Post-transplant cyclophosphamide (PTCy) occupied a prominent place on the stage. This modality of graft-versus-host disease (GvHD) prophylaxis, which was initially developed in the haploidentical HSCT setting, was associated with major benefits so that its use tended to spread across other donor types. PTCy appears to be particularly invested with the benefit of improving outcomes in HSCT from mismatched unrelated donors (MMUD). This appears to be of great usefulness for patients from underserved ethnicities that lack a matched donor. Likewise, management of chronic graft-versus-host disease (cGvHD) had its share of improvement with the result presentation of the REACH3 study. Notably, in this study, ruxolitinib was compared to the best available therapy. The approach of reduced intensity conditioning (RIC) for myeloid malignancies similarly received some attention with a boost to supporting its use for higher-risk myelodysplastic syndrome (MDS), including the elderly. Finally, we present a Phase 1 study, which was designed to improve its efficacy in high-risk myeloid malignancies by adding venetoclax .