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This medwatch is for additional information which was received on apr 29, 2020.D11: concomitant medical products: revitan, proximal part, cylindrical, uncemented, 75, taper 12/14 catalog#: 0100402075; lot#: 2857924.Biolox delta, ceramic femoral head, m, 36/0, taper 12/14 catalog#: 00877503602; lot#: unknown.The manufacturer received x-rays, other source documents 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).
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Investigation results were made available.Additional: d9, h2, h6 correction: b4, b5, g3, g6, h10.Event description: it was reported that the patient was implanted with a revitan femoral stem on (b)(6) 2017.Post surgery there was no proper bone healing around revitan shaft at the coupling point.This resulted in breakage at the coupling between revitan distal and proximal part.Revision surgery took place on (b)(6) 2020.Review of received data: - implantation report of (b)(6) 2017: diagnosis: 15 years after implantation of a left hip prosthesis: massive wear granuloma with destruction of a part of the trochanter minor and the femoral region, loosened cup and damaged pe.Procedure: longitudinal incision including the old scar is made.The patient is not very obese.Using bauer technique the gluteus medius and vastus lateralis muscles are detached, whereby there was a bursa over the trochanter major so that the muscles were already partially detached there.The trochanter major itself is partially fractured and is likely part of the pain.After removal of the joint capsule, serous black material in the sense of wear material drains and a clearly worn polyethylene is seen.The material was collected for both microbiological examination and synovasure rapid test.The rapid test showed no evidence of a bacterial infection.The stem itself seems to be fixed in the distal area.There is a large granuloma which partially extends until trochanter minor and below, and corresponding granulation tissue.Multiple samples are taken for histology and microbiology testing.Although the stem swings relatively freely proximally it is firmly fixed in the distal region.Thus, a 2.5 cm slit is made with the saw and then by some splitting of the femur the stem can be knocked out.A cerclage is applied immediately to secure the area.Moving to the cup, after removal of the soft tissue around the cup, the insert and then the four anchoring screws were removed.Only one screw was still fixed, the others were loose.The shell can be taken out relatively easy with a chisel blow so a loosening can be assumed.The bottom of the acetabulum also shows large granulomas around the screws as well as into the ischium and towards the bottom of the acetabulum.The defect in the bottom of the acetabulum is filled with allograft bone and bone chips.Jet lavage, drilling of anchoring holes and reaming of the acetabulum to size 54 is performed.A cup size 52 is cemented in place.After hardening of the cement the femur is reamed up to size 18.A trial 75 mm proximal part is tried on the rasp to ensure good tension on the soft tissue, to avoid a dislocation tendency, as well as to compensate for the difference in leg length.The definitive prosthesis is assembled and then hammered in.Cancellous bone chips are inserted into the granulation area and repositioning is done.The trochanter major is re-fixed with two kirschner wires and everything is well held in place with an eight tour cerclage.Overall there are very stable, good conditions.Irrigation is made and filling with the remaining bone chips.After image documentation, the muscles are re-adapted at the trochanter major.After image documentation, re-irrigation and wound closure are performed.- revision report of (b)(6) 2020: diagnosis: 3 years after a stem revision with a revitan stem and trochanter cerclages due to a large foreign body granuloma in the proximal femur.Now, fatigue fracture with non-ossifying proximal portion of the femur procedure: the longitudinal skin incision is extended distal and proximal.First, the bone and stem fractures are located and inspected.The distal region appears mainly stable.Proximally it can be seen that several bone scales lie on top of each other and unfortunately there was no bony reintegration here and therefore the stem probably also failed due to fatigue.The capsule is resected towards the joint.The head is dislocated.The whole thing is then rotated and the proximal part of the stem can then be carefully pulled out.A relatively large amount of foreign body granuloma respectively titanium metal wear can now be seen.This is massively scraped out with the sharp spoon and partially remains of the bone are removed.Medially, no bone has formed at all; there is granulation or scar tissue.Everything is cleaned and samples are taken.The further steps of the revision report describe the steps to: remove the firmly seated distal part of the stem, to implant a cpt cemented stem with a biolox delta xl head, to re-fix the bone parts with a cerclage and re-adapt the muscles.- bfarm user report of (b)(6) 2020 apart from the information already mentioned above, the bfarm user report does not contain additional information relevant to the investigation.- email from (b)(6) to zimmer biomet, sent on (b)(6) 2020.The email informs about the height and weight of the patient, filled in on the first page of this report.It is mentioned that the patient can move with a rollator up to 500 m.Note of the author: the given height and weight of the patient result in a bmi of 29.4 which can be classified as overweight according to the bmi scale (bmi 25 - 30).- x-rays a cd with x-rays, pre-revision planning and a ct scan was received.Some of the x-rays are accompanied by diagnostic reports.The information from these diagnostic reports is included below and an additional evaluation of the author of this report is added.The ct images are not evaluated.Pelvis overview taken on (b)(6) 2017: diagnostic report by prof.Dr.Funke: fall with breakage of total hip replacement? state after total hip replacement (thr) on the left side.In addition, wire cerclage of the greater trochanter and in the proximal femoral stem.Regular articulation, inconspicuous position of the prosthesis.No periprosthetic fracture, no bony injury.Evaluation of the author: on the medial side there are two bone pieces with no detectable form fit with the proximal part of the stem.On the lateral side of the proximal part of the stem, the trochanter major is fixed with two kirschner wires and a cerclage.It seems that the cerclage is in contact with the stem medially.Pelvis overview taken on (b)(6) 2018: diagnostic report by prof.Dr.Funke: not available evaluation of the author: compared to the previous view, the situation with two bone pieces with no detectable form fit can still be recognized.Further, the trochanter major appears separated from the rest of the bone just above the transition between the distal and proximal part of the stem and migrated proximally together with the osteosynthesis materials.It could be that both the cerclage cable and the kirschner wires are in contact with the stem.Pelvis overviews taken on (b)(6) 2020: diagnostic report by prof.Dr.Funke: suspected dislocation of the thr.State after thr on the left side.Fracture of the prosthesis at the height of the proximal part of the stem.Evaluation of the author: compared to the previous study date there is a fracture of the connection pin of the revitan stem.The proximal part of the stem is tilted medially and its distal end is shifted laterally.The situation with two bone pieces with no detectable form fit and separation of the trochanter major can still be recognized.In addition the kirschner wires are fractured.Pelvis overview and second view of the left hip taken on (b)(6) 2020: diagnostic report by prof.Dr.Funke: not available evaluation of the author: the x-rays show the situation after revision of the stem.Product evaluation: - visual examination: the connection pin of the revitan stem is fractured in the non-blasted area.The fracture is located approximately 0 to 2 mm below the proximal end of the distal part.The proximal part of the connection pin is still assembled to the proximal part of the revitan stem.The proximal and distal fracture surfaces show a fatigue fracture starting from the lateral side.Both fracture surfaces show a slight blackish discoloration on the medial half.Macroscopically, as far as visible, no defects that could have triggered or favored the fracture were found on the fracture surfaces.On the proximal fracture surface a partially polished area and some scratches can be recognized while the distal fracture surface shows only scratches.Some damage is visible on the medial shoulder and the posterior edge of the face surface of the proximal part.On the face surface of the distal part and on the anterior and posterior shoulders, scratches and nicks can be seen, most probably deriving from revision surgery.In addition, a worn mark is present on the medial side of the face surface.On the proximal part of the revitan stem, revision damage in the form of scratches can be seen on the neck and anchoring surface.There are no signs of bone ongrowth on the anchoring surface of the proximal stem part.A vertical worn area can be observed on the anterolateral side of the proximal part.A smaller worn area can be noticed on the medial side.Below this area there are some slight horizontal marks visible.A slightly polished area can also be seen on the medial side just above the anchoring surface.Polished areas are visible on the anterior and posterior side.In addition small polished spots/lines can be recognized on the entire anchoring surface.On the proximal fracture part of the connection pin there is a half circumferential stripe revealing surface changes adjacent to the fracture surface.Closer inspection of the stripe with a low power microscope revealed smeared material and fretting.Adjacent to the stripe joins the original surface followed by the blasted area.On the latter there are some scratches on the anterior, posterior and lateral side as well as a polished area on the posterior side.Revision damage in the form of coarse scratches, polishing and drill marks can be observed on the anchoring surface of the distal part of the revitan stem.Bone attachments are visible in the finned region.In the as-received condition the biolox delta head and the proximal part of the revitan stem were still assembled.For better handling the parts were disassembled.Before the disassembly the stem to head position was marked.The head shows diffuse metallic smearing on the articulation surface as well as on the bottom bevel.These derived probably from revision surgery and/or shipment of the explants to zimmer biomet as the parts arrived packaged in one plastic bag without separate protection of the single parts.The head taper shows the commonly observed material transfer from the stem taper indicating a proper fixation of the head on the stem and a material track probably deriving from its removal.Review of product documentation: - device purpose: this device is 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.Conclusion: a revitan stem was implanted in (b)(6) 2017 due to massive wear granuloma with destruction of a part of the trochanter minor and femoral region.After the stem was placed, cancellous bone chips were inserted into the granulation area and the trochanter major was re-fixed with kirschner wires and a cerclage.Overall very stable, good conditions were seen.After 2 years and 3 months in vivo the revitan stem was revised due to a fracture of the connection pin.Based on the investigation the reported event can be confirmed.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).The fracture occurred due to fatigue in the non-blasted area of the connection pin, few millimeters below the proximal end of the distal stem part.The fracture origin area is located on the lateral side of the stem.Macroscopically, as far as visible, no defects that could have triggered or favored the fracture could be found on the fracture surfaces.On the proximal fracture part of the pin there is a half circumferential stripe revealing a mixture of surface changes.It is unknown if the stripe existed already before the start of the fracture or developed exclusively as a concomitant phenomenon.On the x-rays at hand (only pelvis overviews) it can be observed that on the medial side of the proximal stem part, immediately after implantation and throughout the time in vivo, there were two bone pieces with no detectable form fit with the part.The trochanter major was fixed during implantation of the revitan stem with kirschner wires and a cerclage.However, approximately 6 months after implantation it can be recognized that the trochanter major separated from the rest of the bone and migrated proximally together with the osteosynthesis materials.The x-rays taken just before revision of the revitan stem show an unchanged situation in the proximal femur.In agreement with the x-rays at hand, the revision report states that in the proximal region of the femur several bone scales lie on top of each other and there was no bony reintegration in this region.Further, it is stated that medially, no bone has formed at all and only granulation or scar tissue was found.On the retrievals at hand, bone attachments could be observed on the finned region of the distal part of the revitan stem but not on the proximal part.The worn areas and the slight horizontal marks seen on the proximal part of the stem point to contact between the part and the cerclage/kirschner wires, as also observed on the x-rays at hand.The polished areas of different appearance on the anchoring surface of the proximal part indicate movement between the part and the surroundings.Based on the above described findings, the proximal bone support of the revitan stem immediately after implantation and throughout the entire time in vivo can be interpreted as suboptimal.Thus, it can be hypothesized that the suboptimal proximal bone support, especially on the medial side, in combination with other factors, e.G.The surface changes observed on the connection pin and the patient¿s obesity, may have contributed to the fracture.It is unknown to which extent each factor had an influence on the sequence of events and if there were other influencing factors.The (revitan® revision stem system) package insert that accompanied the proximal part of the revitan stem points to these facts under the (warnings) section: - heavy patients who engage in high levels of physical activity and who do not have proximal bone support, especially medially, are subject to a risk of implant failure when a modular revision stem is used.In such cases the surgeon should consider surgical options to ensure proximal bone support or switching to a monobloc revision stem.In addition, the surgical technique available to the operating surgeon at the time of implantation indicates on page 3 that (the revitan hip system is not designed for use in a fully unsupported proximal femur.Bone stock of adequate quality must be present and appraised at the time of surgery.For patients with severe proximal deficiency, a surgeon should consider surgical options to ensure proximal bone support (such as medial and/or lateral strut grafts) or switching to a monoblock revision stem).Based on the given information and the results of the investigation, we were not able to identify a specific root cause for this issue.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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