Through anatomic repair, stable function of the AC joint can be achieved in an anatomic manner.

Immediate anatomical reduction of an acute AC separation with flip-button devices provides satisfactory clinical results at intermediate-term follow-up. This technique should be performed by an experienced arthroscopist; tunnel and button placement are of utmost importance to avoid postoperative failure or loss of reduction.

There is great interest in how bone marrow derived stem cells make fate decisions. Numerous studies have investigated the role of individual growth factors on mesenchymal stem cell differentiation, leading to protocols for cartilage, bone and adipose tissue. However, these protocols overlook the role of biomechanics on stem cell differentiation. There have been various studies that have applied mechanical stimulation to constructs containing mesenchymal stem cells, with varying degrees of success. One critical fate decision is that between cartilage and bone. Articular motion is a combination of compressive, tensile and shear deformations; therefore, one can presume that compression alone is unlikely to be a suffi cient mechanical signal to generate a cartilage-like tissue in vitro. Within this study, we aimed to determine the role of shear on the fate of stem cell differentiation. Specifi cally, we investigated the potential enhancing effect of surface shear, superimposed on cyclic axial compression, on chondrogenic differentiation of human bone marrow-derived stem cells. Using a custom built loading device we applied compression, shear or a combination of both stimuli onto fi brin/polyurethane composites in which human mesenchymal stem cells were embedded, while no exogenous growth-factors were added to the culture medium. Both compression or shear alone was insuffi cient for the chondrogenic induction of human mesenchymal stem cells. However, the application of shear superimposed upon dynamic compression led to signifi cant increases in chondrogenic gene expression. Histological analysis detected sulphated glycosaminoglycan and collagen II only in the compression and shear group. The results obtained may provide insight into post-operative care after cell therapy involving mesenchymal stromal cells.

Autologous chondrocyte implantation after failed microfracturing appears to be associated with a significantly higher failure rate and inferior clinical outcome when compared with ACI as a first-line treatment.

First-generation ACI leads to satisfying clinical results in terms of patient satisfaction, reduction of pain, and improvement in knee function. Nevertheless, full restoration of knee function cannot be achieved. Although MRI reveals lesions in the majority of the cases and the overall MOCART score seems moderate, this could not be correlated with long-term clinical outcomes.

High tibial osteotomy for the treatment of medial compartment knee osteoarthritis in the active patient demonstrated favorable clinical results and allowed patients to return to sports and recreational activities similar to the preoperative level.

Therapeutic case series, Level IV.

The study identifies clear facts that significantly increase the risk of revision surgery. These facts can be easily obtained preoperatively and may be taken into consideration when indicating ACI.