Theoretical Strength Comparison of Bioabsorbable (PLLA) Plates and Conventional Stainless Steel and Titanium Plates Used in Internal Fracture Fixation

Abstract

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.

Feasibility of Application of the Newly Developed Nano-Biomaterial, β-TCP/PDLLA, in Maxillofacial Reconstructive Surgery: A Pilot Rat Study

“…The complete degradation of pure-phase β-TCP in humans and animal models occurs within a 6–12-month period [ 47 ], which is far quicker than PDLLA (12–30 months) [ 7 , 48 , 49 ] and β-TCP/PDLLA (9–19 months) [ 50 , 51 ]. The rapid resorption will provide more space for tissue ingrowth and release large amounts of Ca 2+ and P 5+ ions into the milieu, which are essential for osteoblast maturation and bone formation [ 52 ].…”

Interactions b/w Collagen and Polylactic-Acid Molecular Models Due to DFT Calculations

“…This gradual degradation is desirable for a support structure, because it gradually transfers the load to the body (e.g. the bone) as that area heals [7].…”