The U.S. Food and Drug Administration (FDA) has issued a recall notice providing updated instructions related to the placement of Stryker Corporation patient-fitted unilateral or bilateral temporomandibular joint (TMJ) prostheses.
The concern does not involve the implant materials or overall design of the device, but rather the selection and placement of a fixation screw used during implantation. The prosthesis is secured using a small screw- only a few millimeters long – that is inserted through the hole in the implant and screwed into the temporal bone of the skull.
The FDA alert followed a review of a case in which the screw length extended beyond the thickness of the temporal bone into the outer parts of the brain space. In this situation, the screw tip would first encounter cerebrospinal fluid, which bathes and cushions the brain, followed by three protective membranes, the meninges, before potentially reaching the brain itself.
Indeed, adverse reactions to an extended screw length are exceedingly rare, and FDA reports that Stryker Corporation has notified healthcare providers of the potential risk.
Eric Granquist, DMD, MD, Associate Professor of Clinical Oral & Maxillofacial Surgery/Pharmacology at the University of Pennsylvania, offered the following explanation: “In general, screws in the temporal bone that are bicortical (span the entire length of the bone) have an extremely low risk of resulting in a complication or adverse outcome. In fact, it is common in neurosurgical and craniofacial procedures for biocortical screws to extend 1-2 mm beyond the cranial bone without causing an adverse issue for the patient. The complications listed in the FDA notice are potential risks associated with the screws being too long, but again, these complications would be extremely unlikely to occur in a TMJ implant.”
What this means for patients:
For individuals who have had or are considering TMJ replacement surgery, this update highlights the importance of individualized care and open communication with your surgical team. If you have questions about your implant or experience any new or unusual symptoms, consider contacting your healthcare provider.
We will continue to monitor this issue and share updates as more information becomes available.
Read the FDA alert:
https://www.fda.gov/medical-devices/medical-device-recalls-and-early-alerts/reconstruction-prosthesis-correction-stryker-updates-use-instructions-patient-fitted-tmj-implants?utm_medium=email&utm_source=govdelivery
Note: A millimeter is an extremely small measure- approximately the size of the tip of a sharpened pencil or one to two grains of sand.