Rigi10™ Malleable Penile Prosthesis
Also Known As
Device malfunction, implant failure, prosthetic breakdown, component breakage, structural failure, device nonperformance, equipment failure (in a medical device context).
Definition
Mechanical failure, in the context of medical devices and implants, refers to the nonperformance or inability of a device, or its components, to fulfill its intended function for a specified duration under expected physiological and environmental conditions.¹ It signifies a structural or operational fault within the device itself, distinct from failures due to biological responses like infection or rejection, although these can sometimes contribute to or result from mechanical issues. Mechanical failures can encompass a range of issues, including material degradation, component fracture, wear and tear, displacement, or malfunction of moving parts. For instance, in implantable devices such as penile prostheses, mechanical failure often manifests as fluid loss from components, tubing fractures, or cylinder tears, leading to the inability of the device to maintain rigidity or function as intended.² These failures can arise from defects in fabrication, degradation of materials over time, or stresses imposed during normal use or due to unforeseen circumstances.¹ The consequences of mechanical failure can range from a simple loss of device efficacy to more severe patient harm, necessitating revision surgery and potentially impacting the patient’s quality of life.¹
Clinical Context
Mechanical failure is a critical consideration across a vast spectrum of medical specialties where implantable or external medical devices are utilized. It becomes clinically relevant when a device ceases to perform its intended therapeutic or diagnostic function due to an intrinsic flaw in its design, materials, or manufacturing, or due to wear and tear over its operational lifespan.¹ This can occur in numerous devices, including but not limited to cardiovascular implants (e.g., pacemakers, defibrillators, mechanical circulatory support systems), orthopedic prostheses (e.g., hip and knee replacements), urological devices (e.g., inflatable penile prostheses, artificial urinary sphincters), and drug delivery systems (e.g., insulin pumps).¹²
The presentation of mechanical failure varies significantly depending on the type of device and its function. For instance, in mechanical circulatory support devices, failure might manifest as alarms, altered blood flow, or sudden hemodynamic compromise, potentially leading to acute heart failure or cardiogenic shock.¹ In the case of inflatable penile prostheses, mechanical failure, often due to fluid leaks from tubing or cylinders, results in the inability to achieve or maintain an erection, necessitating surgical revision.² For joint replacements, mechanical failure can present as pain, instability, loosening of the implant, or fracture of a component, leading to loss of mobility and requiring revision arthroplasty.
Diagnosis of mechanical failure typically involves a combination of patient-reported symptoms, clinical examination, device-specific interrogation (for electronic implants), and imaging studies such as X-rays, CT scans, MRI, or ultrasound to assess the structural integrity and positioning of the device. Laboratory tests may be used to rule out other causes like infection.
Management of mechanical failure almost invariably involves surgical intervention to repair or, more commonly, replace the failed device or its components.² This can range from relatively straightforward component exchange to complex revision surgeries, especially if there has been associated damage to surrounding tissues. The implications for patient care include the burden of additional surgical procedures, associated risks of anesthesia and infection, potential for incomplete restoration of function, psychological distress, and increased healthcare costs. Expected outcomes following revision for mechanical failure are generally aimed at restoring device function and alleviating symptoms, but success rates can vary depending on the complexity of the failure and the patient’s overall health status.² Prevention strategies focus on robust device design, rigorous pre-market testing, quality control in manufacturing, appropriate patient selection, and meticulous surgical technique.¹