What is a prosthetic device?

What is a Prosthetic Device?

A prosthetic device is an artificial replacement for a missing or damaged body part, designed to restore function, appearance, or both, using synthetic materials that substitute for native tissue or organs. 1, 2

Core Definition and Purpose

• Prosthetic devices are mechanical or synthetic constructs implanted or attached to the body to replace anatomical structures that are absent, damaged, or non-functional 1
• These devices aim to restore both aesthetic appearance and functional capacity using materials that mimic the characteristics of native tissue 3
• Prosthetics serve three primary purposes: functional restoration, cosmetic appearance, and psychological wholeness for the patient 4

Types of Prosthetic Devices

Cardiovascular Prosthetics

• Prosthetic heart valves are mechanical or biological devices that replace diseased native heart valves, made from either non-biologic materials (mechanical), biologic materials (bioprosthetic), human tissue (allograft), or the patient's own tissue (autograft) 1
• Mechanical prosthetic valves use durable synthetic materials like titanium or carbon, while bioprosthetic valves use treated animal or human tissue 1
• Transcatheter prosthetic valves are placed percutaneously without open-heart surgery 1

Orthopedic Prosthetics

• Prosthetic joints replace damaged or diseased joints (hip, knee, temporomandibular) using materials like titanium, cobalt-chromium-molybdenum alloys, and ultra-high molecular weight polyethylene (UHMWPE) 1
• Custom patient-specific prostheses are designed using CAD/CAM technology based on CT imaging to ensure optimal fit and function 1
• Lower limb prostheses for amputees incorporate microprocessor-controlled joints, advanced materials, and osseointegrated (bone-anchored) attachment systems 5, 6

Urologic Prosthetics

• Penile prostheses are mechanical devices implanted within the corpora cavernosa that provide rigidity for sexual intercourse in men with erectile dysfunction 2
• Malleable prostheses maintain constant rigidity but can be bent into different positions 2
• Inflatable prostheses (two-piece or three-piece designs) provide more natural appearance with cylinders, pump mechanisms, and fluid reservoirs 2

Craniofacial Prosthetics

• Cranioplasty prostheses replace skull defects using materials like polymethylmethacrylate (PMMA) or titanium 7
• Soft-tissue prosthetics restore facial features (ear, nose, eye) using advanced polymers that mimic skin and tissue characteristics 3

Materials and Construction

• Modern prosthetic materials include titanium alloys, cobalt-chromium, UHMWPE, carbon fiber, and biocompatible polymers 1, 2
• Infection-inhibiting coatings (rifampin, minocycline, hydrophilic coatings) are applied to reduce infection risk in implanted prostheses 2
• Space-age materials and advanced manufacturing techniques (3D printing, CAD/CAM) have revolutionized prosthetic design and customization 3, 8

Key Clinical Considerations

• Prosthetic implantation is typically irreversible, particularly for cardiovascular and urologic devices 2
• All prosthetic devices carry risks including infection (1-2% with modern coated devices), mechanical failure (6-16% at 5 years for some devices), and need for reoperation 2
• Modern prosthetic valves are MRI-compatible at 1.5 Tesla field strength 2
• Prosthetic devices require ongoing surveillance with imaging (echocardiography, CT) to detect dysfunction, thrombosis, or structural deterioration 1

Historical Evolution

• Prosthetic use dates to ancient Egypt (15th century BC) with wooden and leather toe prostheses 4
• Ambroise Paré invented mechanical prosthetic hands in the 16th century using catches and springs 4
• The 20th century shift from natural to synthetic materials brought significant improvements in fabrication and realism 3
• Recent decades have seen explosive growth driven by microprocessor technology, advanced materials, and targeted surgical techniques like osseointegration and targeted muscle reinnervation 5, 6