Archives of orthopaedic and trauma surgery
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Arch Orthop Trauma Surg · Sep 2012
Wear patterns of tibiofemoral articulation in osteoarthritic knees: analysis and review of literature.
Osteoarthritis is a degenerative joint disease characterized by progressive erosion of the articular cartilage. The sites of erosion of articular cartilage have been reported, but no explanation for this particular pattern has previously been suggested. ⋯ In osteoarthritis of the knee joint, the middle third of both the femoral and tibial articular surfaces is most commonly involved in wears, followed by anteromedial and posterolateral compartments both for tibial and femoral surfaces. The wear patterns in the ACL-deficient knee changes due to altered loading characteristics.
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Arch Orthop Trauma Surg · Sep 2012
Viscoelastic adaptation of tendon graft material to compression: biomechanical quantification of graft preconditioning.
The tensile viscoelastic behaviour of tendon tissue is of central biomechanical importance and well examined. However, the viscoelastic tendon adaptation to external compression, such as when a tendon graft is fixated with an interference screw, has not been investigated before. Here, we quantify this adaptive behaviour in order to develop a new method to mechanically precondition tendon grafts and to better understand volumetric changes of tendinous tissue. The hypothesis of this study was that under compressive loads, tendon grafts will undergo a temporary volumetric (and therefore diametric) reduction, due to the extrusion of water from the tendon. ⋯ The viscoelastic behaviour of hamstring tendon grafts under pressure allows preconditioning of the grafts for reduction of volume and diameter and therefore to drill a smaller bone tunnel, retaining more of the original bone. At the same time, the collagen content of the transplant is preserved and a tight fit of the transplant in the bone tunnel achieved.
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Arch Orthop Trauma Surg · Sep 2012
Comparative StudyThe optimal carrier for BMP-2: a comparison of collagen versus fibrin matrix.
The aim of our study was to investigate in vitro and in a new in vivo rat model for impaired bone healing whether a low dose BMP-2 preparation in fibrin would be equivalent or better than the combination of collagen and a high dose of BMP-2 which is currently in clinical use. ⋯ We conclude that fibrin matrix is an excellent carrier for BMP-2 and that it provides equivalent results with a sevenfold lower dose of BMP-2 compared with ACS.