Orthopedic applications

Successful applications of materials in medicine have been experienced in the area of joint replacements, particularly artificial hips. As a joint replacement, an artificial hip must provide structural support as well as smooth functioning. Furthermore, the biomaterial used for such an orthopedic application must be inert, have long-term mechanical and biostability, exhibit biocompatibility with nearby tissue, and have comparable mechanical strength to the attached bone to minimize stress. Modem artificial hips are complex devices to ensure these features. 

Laurencin CT et al (1999) Tissue engineering orthopedic applications. Annu Rev Biomed Eng 1 19 16... 

Photopolymerization of Novel Degradable Networks for Orthopedic Applications... 

Xu, T. Pruitt, L. Diamond-like carbon coatings for orthopedic applications an evaluation of tribological performance. J. Mater. Sci. Mater. Med. 1999, 10, 83-90. 

Medical Textiles. UK International Newsletters. ISSN 0266-2078. Covers technical developments in materials and applications—fibres, yams and fabrics, equipment, surgical and orthopedic applications, dental uses, and hygiene— together with standards, market and industry news. 

Other biomedical applications of polymers include sustained and controlled drug delivery formulations for implantation, transdermal and trans-cornealuses, intrauterine devices, etc. (6, 7). Major developments have been reported recently on the use of biomaterials for skin replacement (8), reconstruction of vocal cords (9), ophthalmic applications such as therapeutic contact lenses, artificial corneas, intraocular lenses, and vitreous implants (10), craniofacial, maxillofacial, and related replacements in reconstructive surgery (I), and neurostimulating and other electrical-stimulating electrodes (I). Orthopedic applications include artificial tendons (II), prostheses, long bone repair, and articular cartilage replacement (I). Finally, dental materials and implants (12,13) are also often considered as biomaterials. 

Gledhill HC, Turner IG, Doyle C (1999) Direct morphological comparison of vacuum plasma sprayed and detonation gun sprayed hydroxylapatite coatings for orthopedic applications. Biomaterials 20 315-322 Graham S, Brown PW (1996) Reactions of octacalcium phosphate to form hydroxylapatite. J Crystal Growth 165 106-115... 

It has exceptionally good optical properties its transparency has made it a popular substitute for glass in apphcations where breakage must be avoided (plexiglass). It has a variety of industrial uses including automotive parts and glazings. PMMA was the first implanted synthetic polymeric biomaterial it was used as a hip prosthesis in 1947 (see USP XVIII, The Pharmacopia of the USA, (18th Revision), US Pharmacopoeia Convention, Inc., Rockville, MD, 1 September 1980). PMMA is currently used in orthopedic applications, as bone cement, and in intraocular lenses. 

When disks produced from the hexyl esters of the polymers indicated in Equations A.2-15 and A.2-16 were implanted subcutaneously in rats, mild tissue responses were observed, comparable to the response produced by implantation of pLA or polyethylene disks [31]. These materials are being evaluated for orthopedic applications [32]. 

PDS is produced by polymerization of p-dioxanone. The polymer has unusually high flexibility and, unlike copolymers of lactic and glycolic acid, can be used to produce a variety of monofilament sutures. Since PDS is a polyester, like pLA and pGA, the polymer chains break down by hydrolysis. Currently, PDS is also used in orthopedic applications (Orthosorb ), as a fixation element for bone repair. 

Ertel, S.I. and J. Kohn, Evaluation of poly(DTH carbonate) a tyrosine-derived degradable polymer, for orthopedic applications. Journal of Biomedical Materials Research, 1995, 29, 1337-1348. 

While many studies have investigated the electrodeposition of chitosan for biosensor applications [136-138] and dental and orthopedic applications, research has... 

Yao C, Webster TJ (2006) Anodization a promising nano-modification technique of titanium implants for orthopedic applications. J Nanosci Nanotechnol 6(9-10) 2682-2692... 

The main requirement imposed on all polymer biomaterials applied in medicine is a combination of their desired physicochemical and physicomechanical characteristics with biocompatibility. Depending on particular applications, the biocompatibility of polymers can include various requirements, which can sometimes be contradictory to each other. Thns, in the case of artificial vessels, drainages, intraocular lenses, biosensors, or catheters, the interaction of the polymer with a biological medium should be minimized for the rehable operation of the corresponding device after implantation. In contrast, in the majority of orthopedic applications, the active interaction and fusion of an implant with a tissne is required. General requirements imposed on all medical polymers consist in non-toxicity and stability. 

Hulbert S.F. and Klawitter J.J. 1971. Application of porous ceramics for the development of load-bearing internal orthopedic applications. Biomed. Mater. Symp. pp. 161 229. 

---