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Investigation results were made available.Event description: it was reported that the patient had a motorcycle accident that resulted in a left femur fracture which was treated with a left ncb distal femur plate on (b)(6) 2018.Postoperatively, the plate fractured and the patient underwent revision surgery on (b)(6) 2018.Review of received data: received documents: implantation report from (b)(6) 2018: postoperative diagnosis: femoral shaft fracture, grade i soft tissue damage due to closed fracture.Treatment: open reduction, osteosynthesis with angle stable ncb plate and cerclage wires.Procedure: approx.20 cm long incision and reposition of the spiral fracture with verbrugge forceps, followed by fixation with 2 cerclage wires.Overall good fracture alignment, minor revocation to the valgus malposition.Fixation of a 13-hole ncb plate in the condylar area with a kirschner wire and one screw in the most proximal screw hole.The revocation and valgus malposition in the fracture area is reduced to the plate using a verbrugge forceps, thereby straightening the femoral axis.Fixation with 12 screws locked with locking caps.Partial weight bearing of 20 kg for 6 weeks.Physician's letter from klinik kösching, dated (b)(6) 2018: stationary stay from (b)(6) 2018 to (b)(6) 2018.Diagnosis: distal spiral femoral fracture left (ao 33a2.1) and non-displaced fracture of the third rib right.Treatment: open reduction and osteosynthesis on (b)(6) 2018.Anamnesis: patient presented to the emergency with left thigh pain close to the left knee after a motorcycle accident (patient had fallen on the left side).Condition after left high tibial osteotomy in 2016.Findings: left thigh swollen, krepitation at the distal femur, abnormal varus stress test in the knee.Closed fracture.Surgical report from (b)(6) 2018: diagnosis: ncb plate fracture 5 weeks after osteosynthesis of left femur fracture.Treatment: removal of osteosynthesis material, re-osteosynthesis with a ncb periprosthetic distal plate and two cerclage wires.Anamnesis: patient had osteosynthesis on (b)(6) 2018.The patient reported worsening of the condition for a week, and yesterday the patient heard a cracking sound.Procedure: access through previous incision.Removal of all locking caps, removal of all screws, removal of the plate.The cerclage wires have loosened and are removed.Reposition of the slightly mobile fracture and re-osteosynthesis.Partial weight bearing of 10-20 kg for 8 weeks.Physician's letter from klinik kösching, dated (b)(6) 2018: stationary stay from (b)(6) 2018 to (b)(6) 2018.Anamnesis: the patient reported worsening of the condition without trauma or full weight bearing.The knee appears to flex outward.Otherwise, no other relevant information is included.X-ray analysis: the following x-ray analysis has been performed by a health care professional.The review of the x-rays can be summarized as follows: the radiographs taken prior to the reduction show an extra-articular supracondylar obliquely oriented spiral fracture with a large fracture wedge reaching proximally.Intraoperative x-ray images from (b)(6) 2018 show the reduced and fixated femoral fracture with a ncb plate, 12 screws, and two cerclage wires.In the lateral view, the proximal end of the fracture wedge can be seen dorsally above the proximal cerclage wire.On (b)(6) 2018, the upper and lower ends of the fracture wedge can be seen in the lateral projection.The fracture is clearly visible.No evidence of failure or loosening of the osteosynthesis material.In the ap projection, it can be seen that the cerclage wires are not attached to the plate with a cable or hex button.In addition, the locking cap of the distal cerclage wire is positioned directly below the ncb plate; there is no visible contact between the locking cap and the plate at the time of imaging.On radiographs from (b)(6) 2018 visible plate fracture through the 9th screw hole from proximal, which is not occupied by a screw, located at the upper end of the fracture wedge.In addition, evidence of direct contact of the plate and the locking cap of the distal cerclage wire.Also, radiologically visible fracture of the screw in the 8th screw hole from proximal.The screw fracture is located just below the screw head.Compared to the follow-up of (b)(6) 2018, no indication of relevant bone healing can be seen.Intraoperative images from (b)(6) 2018 show the situation after plate re-osteosynthesis and fixation of the fracture wedge with two cerclage wires.On (b)(6) 2018 and (b)(6) 2018, the femoral fracture with fracture zones and fracture lines is still visible, but appears stable.On (b)(6) 2018 visible callus formation medially, dorsally and ventrally.The low contrast radiographs from (b)(6) 2020 show the development of a pronounced fracture callus and the fracture zones and fracture lines are only partially recognizable.The radiograph taken on (b)(6) 2020 shows the healed fracture after removal of the osteosynthesis material.One screw shaft (screw without screw head) remained in the patient at the upper end of the callus formation.Product evaluation: visual examination: the fractured ncb plate, 4 cancellous screws, 7 cortical screws, 1 unknown screw, 1 broken off screw head, 11 locking caps and 1 locking cap still screwed into the plate were received.The ncb plate is received in three segments.The two separations are perpendicular to the plate axis.One separation corresponds with the fracture seen on the x-rays and runs through the 9th screw hole.The other separation is located between the 10th and 11th screw holes and is assumed to be cut.The bone facing surface of the plate is inconspicuous while the non-bone facing surface shows some fine and coarse scratches.At the distal end of the plate, in the most distal anterior screw hole, there is one locking cap which is screwed in upside down.The proximal fracture surface at the 9th screw hole is polished and worn; the original fracture surface is therefore barely visible.The thread is flattened and deformed, especially on the anterior wall.There is a cut on the non-bone facing surface running from the thread chamfer to the edge of the fracture surface.On the distal fracture surface, a small area of the original fracture surface is still visible and contains progression marks (beachmarks) indicating a fatigue fracture.Again, the thread is deformed, although the deformation is more pronounced on the posterior wall.The second plate separation between the 10th and 11th screw holes was intentionally introduced after plate removal.At the same position, the distal cerclage wire touched the plate, as shown on the radiograph of (b)(6) 2018.Both the proximal and distal cutting surfaces show extensive instrument marks over the entire fracture surfaces.Marks can also be found on the plate surfaces adjacent to the fracture.On the bone facing surface the marks possibly derive from the direct contact of the distal cerclage wire and the plate.Nevertheless, based on the instrument marks and the cut a detailed assessment of this plate section is no longer possible.Two out of the four received cancellous screws have spiral thread marks on the non-threaded parts.The marks most likely occurred due to contact with the plate¿s thread during implantation and / or removal.The single screw head belongs to a cortical screw.Review of product documentation: device purpose: all involved devices are intended for treatment.Product compatibility: the product combination was approved by zimmer biomet.Dhr review: review of the device history records identified no deviations or anomalies during manufacturing.Review of instruction for use (ifu): implants and implant parts must only be combined with components belonging to the same system.Do not use any component if damage is found or caused during setup or insertion.The load-bearing capacity of the implant can be compromised by notching, scratching, or striking.Improper selection, placement, positioning, and fixation of the implant components may result in unusual stress conditions reducing the service life of the implants.To maintain the integrity of the screw / ncb plate construct, two or more screws are required to be placed into each load bearing fracture fragment.If the fracture is in the distal or proximal cancellous region of the bone, use of all screw holes is recommended.The risk of adverse effects such as material fatigue (implant breakage), implant failure and/or impaired blood circulation, increases with the time the implant is implanted, delayed union, non-union, patient weight, activity level and/or with patients who fail to follow through with the required rehabilitation program.The implant is not as strong, reliable or durable as natural, healthy bone and will fail under normal weight bearing or load bearing in the absence of complete bone healing.Review of surgical technique: as mentioned in the applicable surgical technique products from the zimmer® cable-ready® cable grip system are compatible with the ncb distal femur system.These products provide a positioning point for the cerclage and allow a positioning of the cerclage around the bone and the plate, refer to the data sheet ref 97-2232-015-00 available on www.Zimmerbiomet.Com for more specific instructions.Conclusion: it was reported that a 51-year-old male patient had a motorcycle accident resulting in a left femur fracture, which was treated with a left distal ncb femoral plate on (b)(6)2018.Approx.4 weeks after implantation, the patient's condition began to deteriorate until the patient heard a cracking sound on may 03, 2018.Radiological follow-up revealed an ncb plate fracture, due to which the patient underwent revision surgery on (b)(6) 2018, approx.5 weeks after implantation.The product and the raw material were manufactured according to predefined specifications.No additional complaints for the same reference and lot combination were found.Therefore, the investigation did not identify a nonconformance or a complaint out of box (coob).The obtained radiographs confirm the distal femoral spiral fracture on the left with a large fracture wedge, which was reduced on (b)(6) 2018 with a left ncb plate, 12 screws, and two cerclage wires.On (b)(6) 2018, radiologically visible fracture of the ncb plate through the 9th screw hole from proximal, which was not occupied by a screw.Also visible is a fracture of the screw occupying the 8th screw hole from proximal.After revision surgery with re-osteosynthesis using a distal periprosthetic ncb plate and two cerclage wires the fracture healed over the course of the next 20 months.Finally, the osteosynthesis material was removed on (b)(6) 2020 except of one broken off screw shaft that remained in the patient.Most likely, the received single screw head belongs to the screw shaft that remained implanted.It is unknown if the screw head broke off before or after the plate fractured.The single matte screw could not be assigned.The two cerclage wires, which were found to be loose during revision surgery, were placed between the bone and the plate without being attached to the plate with a cable or hex button, as described in the applicable surgical technique.These products provide a positioning point for the cerclage and allow a positioning of the cerclage around the bone and the plate.It remains unknown at what point in time the cerlage wires became loose.Additionally, the locking cap of the distal cerlcage wire was placed directly under the plate and had direct contact with the plate, at least after fracture.The visual examination of the ncb plate shows two separation sites.The distal separation was an intentionally introduced cut after plate removal.The purpose of this cut remains unknown.The remaining characteristic of the fracture surface indicates a fatigue fracture with a fracture origin at thread chamfer on the non-bone facing plate surface.Macroscopically, nothing was observed that could have contributed to the plate fracture.The deformations on the thread as well as the polishing of the fracture surfaces were introduced by direct contact of the two fracture parts in vivo after the fracture.It is possible that the contact of the fracture parts after the fracture also destroyed evidence of damages to the plate that may have led or contributed to the fracture.Based on the investigation, potential causes of the plate fracture include, but are not limited to, damage to the plate during implantation (e.G.With verbrugge forceps), insufficient fracture reduction, delayed or non-union bone healing, obesity, smoking, and compliance to rehabilitation protocols.In addition, the placement of the cerclage wires underneath the plate and without fixation to the plate using hex or cable buttons may have changed the load distribution of the plate and created a level-arm situation.Combined with the fracture line still clearly visible in the lateral view after reduction, small movements of the bone fracture may have been possible that increased the bending forces on the plate.Because of the multifactorial cause of the fracture, consisting of procedure- and patient-related factors, the exact root cause for the ncb plate fracture could not be identified.The need for corrective measures is not indicated and zimmer switzerland manufacturing gmbh considers this case as closed.Zimmer biomet's reference number of this file is (b)(4).
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