Large diameter chrome cobalt modular heads in hip replacement surgery have caused one of the biggest challenges to face orthopaedic surgeons, manufacturers and regulators in a generation. Increasing numbers of retrieved implants offer the opportunity to look in detail at the modes of failure of these devices. We have examined the mechanical behaviour of the head taper/trunnion using a variety of techniques including:
mechanical testing in a custom-made jig 3D nano-precision form profilometry (RedLux) optical 3D microscopy with focus variation technology electro-chemical testing.Background
Methods
The management of chondral lesions in the knee, especially in young fit patients, remains an area of considerable controversy. Articular cartilage repair or reconstruction techniques may offer these patients alternatives to arthroplasty or realignment osteotomy. The TruFit plug (Smith & Nephew, London, UK) is a synthetic biphasic polymer scaffold that is designed for implantation at the site of a focal chondral defect. It is intended to resorb and allow tissue ingrowth 6-9 months following implantation and may be placed either arthroscopically or via an open approach depending on the site of the lesion. 11 patients with focal chondral defects in the knee underwent TruFit plug implantation. Postoperative management entailed a period of 6 weeks of restricted weight bearing or restricted knee flexion according to implantation site. Radiological evaluation with MRI or CT arthrogram (or both) was conducted at various time points postoperatively according to clinical indication. Functional scoring with the Oxford knee score (OKS), Tegner activity scale and Lysholm score were completed.Background
Methods
