Leonardo Osti

Metalloproteases and tendinopathy.

Matrix metalloproteinases (MMP) are involved in the development of tendinopathy. These potent enzymes completely degrade all components of the connective tissue, modify the extracellular matrix (ECM), and mediate the development of painful tendinopathy. To control the local activity of activated proteinases, the same cells produce tissue inhibitors of metalloproteinases (TIMP). These latter bind to the enzyme and prevent degradation. The balance between the activities of MMPs and TIMPs regulates tendon remodeling, whereas an imbalance produces a collagen dis-regulation and disturbances in tendons. ADAMs (a disintegrin and metalloproteinase) are cell membrane-linked enzymes with proteolytic and cell signaling functions. ADAMTSs (ADAM with thrombospondin motifs) are secreted into the circulation and constitute a heterogenous family of proteases with both anabolic and catabolic functions. Further studies are needed to better define the mechanism of action, and whether these new strategies are safe and effective in larger models.

I.S.Mu.L.T - Rotator cuff tears guidelines

Despite the high level achieved in the field of shoulder surgery, a global consensus on rotator cuff tears management is lacking. This work is divided into two main sessions: in the first, we set questions about hot topics involved in the rotator cuff tears, from the etiopathogenesis to the surgical treatment. In the second, we answered these questions by mentioning Evidence Based Medicine. The aim of the present work is to provide easily accessible guidelines: they could be considered as recommendations for a good clinical practice developed through a process of systematic review of the literature and expert opinion, in order to improve the quality of care and rationalize the use of resources.

The kneeling view: evaluation of the forces involved and side-to-side difference.

The kneeling view is a method to objectively measure posterior knee laxity. However, the actual amount of load applied and the reliability of this method in term of side to side difference are not known. We studies these issues in a group a 25 healthy volunteers who underwent measurements of posterior knee laxity in both knees. A standard digital scale was positioned under both kneeling supports to measure the actual amounts of posterior displacement forces applied. We measured the mass of the subject, the side-to-side difference of the weight applied into anterior aspect of the tibia, and the ratio weight of the subject/ amount of posterior displacement load applied. The average amount of forces applied was at least 75% of the body weight of each subject, with a side-to-side variability of 3.3% of the weight applied. The kneeling view can be considered, in terms of forces applied, a reliable and reproducible alternative method for the routine radiographic evaluation of the posterior knee laxity.

I.S.Mu.L.T. First-time patellar dislocation guidelines

Primary traumatic patellar dislocation is common, particularly in young active individuals. A consensus on its management is still lacking. The present work provides easily accessible guidelines to be considered as recommendations for a good clinical practice developed through a process of systematic review of the literature and expert opinion, to improve the quality of care and rationalize the use of resources. LEVEL OF EVIDENCE Ia.

Apoptosis and rotator cuff tears: scientific evidence from basic science to clinical findings

Introduction Excessive apoptosis has been hypothesized as possible cause of tendinopathy and tear in the tendons of the rotator cuff (RC). Different mechanisms and molecules play a key role in cell regulation. Biological interventions can affect the process of apoptosis to control the tendinopathy process, and may be useful to design new treatments. Source of data We identified basic science, in vitro and in vivo preclinical and clinical studies listed in the Pubmed Google Scholar, CINAHL, Cochrane Central and Embase Biomedical databases in English, Spanish, Italian and French concerning the effects of apoptosis on RC tendons. Areas of agreement The homeostasis between the apoptotic and inflammatory processes is dynamic and controlled by pro- and anti-apoptotic mechanisms and signals, with variable balance in different areas of the RC tendons in human specimens. Areas of controversy Apoptosis can be identified along the whole tendon, not only in the area of the lesion. Therefore, it is not necessary to undertake wide debridement of the torn edges of the tendon when undertaking a repair. Growing points The identification of the various factors that control apoptosis and its mechanisms can help to design new treatments and exert positive effects in the recovery from tendon tears. Areas timely for developing research Further studies are needed to produce clear guidelines to determine how to balance the apoptosis process to reduce the failed healing response found in non-traumatic RC tears.

Preoperative planning for ACL revision surgery

The number of patients undergoing revision surgery following failure of anterior cruciate ligament (ACL) reconstruction has increased over the recent past, following the overall increased number of primary ACL reconstruction performed. Failure of primary ACL reconstruction can be attributed to technical errors, biological failures, or new traumatic injuries. Technical errors include femoral and/or tibial tunnels malposition, untreated associated ligaments insufficiencies, uncorrected lower limb malalignment, and graft fixation failures. Candidates for revision surgery should be carefully selected, and the success of ACL revision requires precise preoperative planning to obtain successful results. Preoperative planning begins with the analysis of the mechanisms of ACL reconstruction failure, and information regarding previous surgery, such as the type of graft implanted, and the position of existing hardware. Appropriate imaging is necessary to evaluate the position of the femoral and tibial tunnels, and abnormal tunnel widening. On the basis of clinical examination and imaging, surgeon can perform an ACL revision procedure in 1 or 2 stages.