First investigation: 1.1.Production process analysis: a review of the dhr demonstrated that the mid-c system was manufactured, tested, and released according to specification.1.2.User (surgeon and patient) information analysis: the x-ray demonstrates that the system reached its maximal elongation, which is the weakest point of the rod.In this position, the transverse process below the implant may generate a force acting on the system that can cause the rod breakage.As part of apifix commitment to continuous improvement, capa #(b)(4) was initiated to further investigate to prevent and minimize the rate of implant breakage.The company investigation indicated that implant breakage can result from trauma, practicing severe sports, development of hyper-kyphosis, inserting the pedicle screws in a wrong trajectory, not working according to the surgical technique, and most commonly from the implant reaching its end of the way.Breakages were evident in 3 main regions, the implant base, the main rod, and the rod's connection to the poly-axial joint.The most common point of failure was the implant rod in implants reaching their maximal elongation.2.Corrective action: over the years, the company already implemented corrective action with the following: in nov 2017, all surgeons received a letter detailing the importance of screw insertion trajectory.The topic is also covered in the company's training presentation.Eco-38, replaced the mid-c 125 that extends by 40 mm to mid-c 125 that extends by 50mm allowing more overlap between the pole and base.Eco-46, a trial tool was added to the surgical tools to aid the surgeon in detecting if access tissue remains below the implant.In march 2020, the topic of practicing severe sports was added to the mid-c training presentation.3.Risk assessment: 3.1.The current device breakage rate due to any reason is 3.6% and is in line with the rate reported in the literature for this type of complication as described in the company's clinical evaluation report ( 0.2%- 15.5%) ( cer dms-727 rev t).The risk of the broken rod has been assessed and found to be acceptable ((b)(4)).3.2.The current curve progression rate is 2.8%.
|