Ceramic on Ceramic bearings in Total Hip Arthroplasty (THA) afford a low friction coefficient, low wear rates and extreme hardness. Significant complications include hip squeak, ceramic fracture and poor polyethylene performance in revision procedures due to imbedding of abrasive microscopic ceramic fragments. We report on the results of this bearing at a minimum of 10 years. A single-centre retrospective review of 449 THAs was performed. Primary outcome measures included aseptic revision and all-cause revision rates at a minimum of 10 years post operatively. Evaluation of functionality was performed with WOMAC and SF-36 scores which were performed pre-operatively and at intervals of 6 months, one year, 2 years, 5 years and 10 years post operatively.Introduction and Objective
Materials and Methods
Damage to articular cartilage is difficult to treat, as it has a low capacity to regenerate. Biomimetic natural polymer scaffolds can potentially be used to regenerate cartilage. Collagen hyaluronic acid (CHyA) scaffolds have been developed in our laboratory to promote cell infiltration and repair of articular cartilage. However, the low mechanical properties of such scaffolds potentially limit their use to the treatment of small cartilage defects. 3D-printed polymers can provide a reinforcing framework in these scaffolds, thus allowing their application in the treatment of larger defects. The aim of this study was to create mechanically functional biomaterial scaffolds by incorporating a CHyA matrix into 3D-printed polymer meshes resulting in an integrated porous material composite with improved mechanical properties for repair of large cartilage defects. 3D-printed meshes were developed to facilitate an architecture suitable for nutrient flow, cell infiltration, and even CHyA incorporation. And the meshes were freeze dried in custom made moulds to create a pore structure suitable for chondrogenesis. Uniaxial compressive testing of the scaffolds revealed improved mechanical properties following reinforcement with printed meshes, with the compressive modulus increasing from 0.8kPa (alone) to 0.5MPa (reinforced structure). The reinforced scaffolds maintained interconnected pores with the mean pore diameter increasing from 130 to 175µm. The reinforcement had no negative impact on MSC viability, with 90.1% viability in reinforced scaffolds at day 7. The compressive modulus of the reinforced CHyA scaffold is close to native articular cartilage, suggesting that this approach can be used for treatment of large cartilage defects.
The gradient structure of osteochondral tissue, with bone, calcified and cartilage regions, challenges the design of biomaterials for defect repair. A novel biomimetic tri-layered collagen-based scaffold, designed to replicate these 3 anatomical layers, has been developed within our group and has shown success as an off-the-shelf product in treatment of focal defects in several animal models by recruiting host cells and directing them to form bone and cartilage in the requisite layers. This study aimed to elucidate the mechanism by which the extracellular matrix macromolecules in the scaffold directed stem cell differentiation in each layer. Tri-layered scaffolds were divided into their three constituent layers. Each layer was individually seeded with rat mesenchymal stem cells (MSCs). Cell infiltration and proliferation, calcium production and sGAG formation were assessed up to 28 days.Background
Methods
