Use of stainless steel or titanium plates with multiple screws to fix fractures internally is the most widely used technique in orthopaedics. Metal plates act as a bridge across the fracture gap and stress shield the fracture site as the bone heals. However, use of metal plates in certain applications can be slightly disadvantageous. Due to the high stiffnesses of metal plates they tend to stress shield the fracture site, which can lead to over all reduction of strength of the healing bone. Also, a secondary surgery has to be performed to retrieve the implant, which can increase the risk to the patient. Use of bioabsorbable plates can overcome these disadvantages. This study compares theoretical bending (four point) strengths of three bioabsorbable poly L-lactic acid (PLLA) plates with a stainless steel plate with four holes and four screws. Three types of bioabsorbable plates have been considered, namely, 1. pure PLLA plate, 2. PLLA with glass fibers, and 3. PLLA with carbon fibers. A strength degradation curve for PLLA has been established.

The processing of high temperture thermoplastic polymers as a hot melt adhesive is one means of joining thermoplastics to metals. The presetn study establishes the role of processing in thermoplastic joining of a titanium alloy (Ti‐6A1‐4V) using thin flim poly(etherketoneetherketoneketone) (PEKEKK). A design of expriments (DOE) was performed to determine the effects of the soak above melt temperature (Tm = 380°C), hold at the isothermal recrystallizztion temeprature (Tiso = ∼ 340°C) and cooling rates on the joint strength, Extended soak times are required to remove the residual spherulitic crystallinity in the polymeric adhesive. Whit the elimination of the residual crystallinity, high‐strength transcrystalline regions are enhanced at the polymer‐metal interface during the hold time at Tiso and during cooling to ambient temperature. Average tensile strengths of 137 MPa were achieved, exceeding the bulk polymer tensile strength of 118 MPa by 16%, X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) show that extended soak times above Tm led to excessive polymer squeeze‐out, resulting int he creation of strength‐reducing shrink voids or unwetted regions. As a result, the failue mode of the joint, which was normally cohesive for high‐strength joints, became a mix of cohesive and adhesive in parts with excessive polymer squeeze out.