Serologic and radiographic outcome of total hip arthroplasty with CoCr modular neck at mid-term follow-up.

PURPOSE: The aim of this study is a radiographic evaluation and to determine serologic values of chromium and cobalt in the blood and urine of patients who have been implanted with a Stryker® ABG II Modular Neck and see if there is correlation with the features of prosthesis and patients. METHODS: The study involves the collection of data from patients operated on for total hip model with the ABG II Modular Neck with a minimum follow-up of 1 year. RESULTS: We evaluated 22 patients who underwent implantation of a hip prosthesis with modular neck in CoCr. Of these, the average Cr in the blood was 0.63 µgL-1 (range 0.1-2.15 µgL-1), the average of Co in the blood was 3.50 µgL-1 (range 0.62-7.78 µgL-1), the average Cr in the urine was 1.24 µgL-1 (range 0.48-2.21 µgL-1), and the average Co in urine was 14.22 µgL-1 (range 3.3-31.2 µgL-1). None of these patients had undergone revision surgery. CONCLUSIONS: Our study seems to indicate that the restoration of offset and age are correlated with the release of metal ions, although the correlation is weak and needs better methodological studies and a greater number of patients to confirm this hypothesis. STUDY TYPE: Case series Level of Evidence 4.

Chondropenia: current concept review.

The term "chondropenia" indicates the early stage of degenerative cartilage disease, and it has been identified by carefully monitoring early-stage osteoarthritis (OA). Not only is it the loss of articular cartilage volume, but it is also a rearrangement of biomechanical, ultrastructural, biochemical and molecular properties typical of healthy cartilage tissue. Diagnosing OA at an early stage or an advanced stage is valuable in terms of clinical and therapeutic outcome. In fact degenerative phenomena are supported by a complex biochemical cascade which unbalances the extracellular matrix homeostasis, closely regulated by chondrocytes. In the first stage an intense inflammatory reaction is triggered: pro-catabolic cytokines such as IL-1ß and TNF-α triggering matrix metalloproteases and aggrecanase (ADAMT-4 and 5), responsible for the early loss of ultrastructural components, such as type II collagen and aggrecan. In addition nitric oxide and reactive oxygen species modulate the physiopathology of the condral matrix inducing apoptosis of chondrocytes through a mitochondria-dependent pathway. In addition, "Lonely Death": chondrocytes, are confined within a dense, avascular extracellular matrix capsule, and can trigger a genetically induced apoptosis and necrosis. The degenerative process starts from a central point and then spreads in a centrifugal manner in depth and in adjacent areas, eventually covering the whole joint; chondropenia represents a journey from the first clinically detectable time-point until it can be characterized as frank osteoarthritis. Currently, there are no instruments sensitive enough which allow a timely diagnosis of chondropenia. Innovative magnetic resonance imaging techniques, such as T2 mapping, can be effective and a sensitive diagnostic instrument for quantifying cartilage volume and proteoglycan content. However, avant-garde biophysical techniques, such as mechanical indenters, ultrasound and biochemical markers (uCTX-II), are rational and scientific tools applicable to the clinical and therapeutic management of early degenerative cartilage disease. The objective of this review on chondropenia is to present a state of the art and innovative concepts.