MAUDE Adverse Event Report: ZIMMER SWITZERLAND MANUFACTURING GMBH ZNN, CMN LAG SCREW, 10.5 MM, 100 MM, INCLUDING SET SCREW; ZIMMER NATURAL NAIL SYSTEM CEPHALOMEDULLARY NAILS

Model Number	N/A
Medical Device Problem Code	Fracture (1260)
Health Effect - Clinical Code	Foreign Body In Patient (2687)
Date of Event	01/18/2021
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
Medical product: cmn femoral nail, ccd 130, left, 11.5 mm, 21.5 cm; item# 47249321311; lot# 2963065; 5.0 mm diameter cortical screw - red fixed angle 3.5 mm hex head; item# 47248403250; lot# 64238296; 5.0 mm diameter cortical screw - red fixed angle 3.5 mm hex head; item# 47248403250; lot# 64270868.The manufacturer did not receive x-rays for review.Other source documents were received and will be reviewed as part of ongoing investigation.The manufacturer did not receive the device for investigation.The device history records were reviewed and found to be conforming.Additional information has been requested and is currently not available.A cause for this specific event cannot be ascertained from the information provided.As soon as supplemental information becomes available an updated report will be submitted.Zimmer biomet¿s reference number of this file is (b)(4).
Event or Problem Description
During the surgery, the head of the cephalic screw fractured making it difficult to remove the screw.The fractured pieces were removed macroscopically and the screw was left in-situ.
Additional Manufacturer Narrative
Additional information was received on feb 26, 2021.This follow-up report is being filled to relay additional information, which was unknown at the time of the previous medwatch.The manufacturer received x-rays for review.Should additional information become available and / or the device(s) be returned for evaluation and an investigation result be available, that changes this assessment, an amended medical device report will be submitted.Zimmer¿s reference number of this file is (b)(4).
Event or Problem Description
Patient was implanted on the left side and during the surgery, the head of the cephalic screw fractured making it difficult to remove the screw.The fractured pieces visible macroscopically were removed and the screw was left in-situ.
Additional Manufacturer Narrative
Investigation results were made available.Event description: it was reported that a left cmn femoral nail was implanted in a 27-year old female patient on (b)(6) 2019.The fracture consolidated and the patient underwent removal of the osteosynthesis material on (b)(6) 2021.During removal the head of the lag screw fractured.All macroscopically visible fractured pieces of the implant were removed.Based on the screw fracture the nail could not be removed and remained in the patient.Review of received data: x-rays: in total six undated x-rays were received.Two images from 20 months ago, 2 images from 17 months ago and two images post-revision.Radiologically, there is significant fracture consolidation on the post-revision images when comparing the images from 20 months ago.In the ap view after revision, mild hypertrophic bone formation can be seen around the two distal screw holes, and the two distal screws have been removed.A sclerotic line is also visible along the cmn nail.The flanks at the end of the lag screw are missing and an uneven edge can be seen.Additionally, on the radiographs from 17 months ago the set screw can been at the proximal end of the nail, while on the post-revision images the set screw can no longer be recognized.Surgical report: surgical report, dated (b)(6) 2021: diagnosis: removal of material from the left femur, more than 18 months after a proximal femur fracture, treated by znn cmn centromedullary nailing.Consolidation was considered satisfactory.Indication for removal of osteosynthesis material given the patient's age.The patient was warned of the risk of non-removal and enlargement of the incisions.Procedure: reopening of the old incision.Removal of the proximal screw.Extraction of the 2 distal screws by widening the incision.The screw heads are not palpable and are completely covered by bone.Release of the screw heads with the osteotome and removal.The head of the cervicocephalic screw (diameter 10.5) is also completely covered with bone.Release of the screw head with the osteotome to reveal the proximal thread.Attaching the cervical screw extraction instrument with good hold in the thread.During the unscrewing movement, the head of the screw breaks off because of the very good hold of the screw in the femoral head.An attempt was made to extract the screw, which only protruded 2-3 mm, using universal pliers, facom, and osteogouge, without success.An attempt was made to recreate a screw impression using a straight osteotome in the titanium screw.Another failure during the unscrewing movement.An attempt was made to remove the cervical screw with a tuning fork hammer in the axis without success.Failure of the various extraction attempts available in the operating room (universal ao nail removal, broken screw ancillary).No large diameter 10.5 left-hand screwdriver available.The thread of the cephalic screw is not destroyed despite the various extraction attempts.Given the high risk of fracture, it was decided to leave the material in place.Closure.Surgical report, dated (b)(6) 2019: diagnosis: a 26-year-old patient presented with a left per-trochanteric fracture following a fall on the stairs.Procedure: reduction of the fracture by external maneuvers under the control of the image intensifier.Placement of the reaming guide.Millimetric reaming to the appropriate size.Placement of the znn cmn nail.Placement of a 8.5 diameter cervicocephalic screw and compression on it.Static and dynamic distal locking.Closure.Product evaluation: the product remained implanted; therefore, visual and dimensional evaluation could not be performed.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.Surgical technique: the removal of the lag screw is described in the zimmer natural nail system ¿ cephalomedullary standard surgical technique.(to remove the lag screw it is not necessary that the set screw is completely removed.Turn the set screw two turns backwards and make sure that the set screw is still engaged in the threads of the nail.It is recommended to use the lag screw cannula as guidance for the lag screw inserter while removing the lag screw.Assemble the lag screw inserter through the lag screw cannula into the lag screw.Use the compression device to push the lag screw cannula to the bone.Make sure the lag screw inserter is fully seated.Hand tighten the lag screw inserter with the 3.5mm hex screwdriver.If a secondary option is needed to remove the lag screw, the cm lag screw extraction device ref 00-2490-090-12 can be used.To use the cm lag screw extraction device, align its axis with the axis of the cm lag screw that is being explanted.The conical thread of the cm lag screw extraction device should then be engaged and rotated in a counter-clockwise motion into the exposed lateral threads of the cm lag screw that is being explanted.The rotation direction is counter-clockwise as the cm lag screw extraction device utilizes reverse-cutting flutes to enable mating to the cm lag screw.While rotating, a constant axial force must be applied to maintain the tool driving into the cm lag screw thread.While continuing to rotate the cm lag screw extraction device counter-clockwise, the cm lag screw that is being explanted will unseat from the bone and can be removed).Review of biocompatibility specification doc nr.120083 rev.03.In accordance with iso 10993-1 (2009) the zimmer natural nail system - cephalomedullary nail (cmn) is categorized as implantable devices with tissue/bone contact for more than 30 days (c - permanent).Biocompatibility evaluation aims to assure that the implanted device does not induce any kind of unexpected body reaction during the life time of the implant.For the biocompatibility evaluation of the zimmer natural nail system - cephalomedullary nail (cmn) we followed the guidelines of the iso 10993-1.Conclusion: it was reported that a left cmn femoral nail was implanted in a 27-year old female patient on (b)(6) 2019.The fracture consolidated and the patient underwent removal of the osteosynthesis material on (b)(6) 2021.During removal the head of the lag screw fractured.All macroscopically visible fractured pieces of the implant were removed.Based on the screw fracture the nail could not be removed and remained in the patient.Based on the x-ray images obtained, the reported event can be confirmed.The flanks of the lag screw broke off leaving an uneven edge at the end of the lag screw.It can be assumed that the mild hypertrophic bone formation at the distal screw holes is due to an increased force transfer from the lag screw via the nail to the two distal screws.The two distal screws were removed during revision.The revision report also confirms the breakage of the lag screw flanks followed by multiple removal attempts.Given the high risk of fracture the osteosynthesis material except of the two distal screws and the set screw was left in place.The quality records show that all specified characteristics have met the specifications valid at the time of production.Therefore, the investigation did not identify a nonconformance or a complaint out of box (coob).Possible causes for the breakage of the lag screw flanks during the removal include: if the contact surface of the instrument and implant is too small, too high forces will be transmitted on the cams which lead to a fracture of this section.Damage of the lag screw with the osteotome during release of the thread.Excessive bone ingrowth onto the lag screw due to long in vivo time of the implant system, which makes high forces needed to remove the screw.The time in vivo was 20 months.Pathogenic bone diseases which affect mechanical properties of the bone (harder/ denser bone substance).Nevertheless, an exact root cause could not be found.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).
Event or Problem Description
Investigation has been completed.

• Brand Name: ZNN, CMN LAG SCREW, 10.5 MM, 100 MM, INCLUDING SET SCREW
• Common Device Name: ZIMMER NATURAL NAIL SYSTEM CEPHALOMEDULLARY NAILS
• Manufacturer (Section D): ZIMMER SWITZERLAND MANUFACTURING GMBH; sulzer allee 8; sulzer industrie park; winterthur 8404 ; SZ 8404
• MDR Report Key: 11343220
• Report Number: 0009613350-2021-00094
• Device Sequence Number: 3479221
• Product Code: HSB
• UDI-Device Identifier: 00889024298453
• UDI-Public: 00889024298453
• Combination Product (Y/N): N
• Initial Reporter Country: FR
• PMA/510(K) Number: K091566
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2019
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: foreign,health professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 04/23/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Operator of Device: Lay User/Patient
• Device Expiration Date: 11/30/2023
• Device Model Number: N/A
• Device Catalogue Number: 47-2485-100-10
• Device Lot Number: 2974487
• Was Device Available for Evaluation?: No
• Was the Report Sent to FDA?: No
• Initial Date Received by Manufacturer: 02/05/2021
• Supplement Date Received by Manufacturer: 02/26/2021; 04/16/2021
• Initial Report FDA Received Date: 02/18/2021
• Supplement Report FDA Received Date: 03/08/2021; 04/23/2021
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• If action reported to FDA under 21 USC 360i(g), list FDA-assigned Recall Number or include a statement: N/A
• Patient Sequence Number: 1
• Concomitant Medical Products and Therapy/Usage Dates: SEE H10 NARRATIVE
• Outcome Attributed to Adverse Event: Hospitalization
• Patient Age: 27 YR