Fractured Whiteside Ortholoc II knee components

Femoral Component Fracture in a Total Knee Arthroplasty Patient With a Persistent Flexion Contracture

This article reports a rare case of a total knee arthroplasty femoral component fracture. Fractures of early knee systems were attributed to design flaws. Modern design failures have been attributed to poor surgical technique or underlying osteolysis. Here, we report a fracture in the Vanguard prosthesis (Zimmer Biomet, Warsaw, IN) 12 years after implantation in a patient with a persistent flexion contracture. The fracture likely occurred due to fatigue failure of the anterior flange secondary to increased stress from a high riding patella. Although femoral component fractures are rare, they should be considered as a potential complication, especially in patients with special load considerations. For these patients, it is essential that the prosthesis be properly supported with clean cuts and an adequate cement mantle.

Fracture of the oxidized zirconium femoral component after total knee arthroplasty

BACKGROUND

Femoral component fracture is a rare complication of total knee arthroplasty (TKA).

CASE

We report a case of oxidized zirconium (Oxinium) femoral component fracture after total knee arthroplasty. The fracture site was the junction of the central and medial flanges. The patellar component and polyethylene insert had delamination at the contact point of the fracture line, and the tibial tray had loosening at the medial side. There was no cement adherence at the component fracture site, suggesting that debonding had occurred at the cement-implant interface in this area. Examination with a scanning electron microscope revealed beach marks, which are characteristic findings of metal fatigue.

CONCLUSION

We considered that the cause of femoral component fracture was a fatigue fracture due to poor fixation of the component to the bone caused by poor osteotomy technique or poor cementing technique. To our knowledge, this is the first case of Oxinium femoral component fracture.

Radiographic False Evidence of a Tibial Baseplate Fracture After Total Knee Arthroplasty

Fracture of the tibial baseplate is a rare but dramatic cause of typically late fatigue failure in the setting of loosening after total knee arthroplasty. A 58-year-old female presented 4 months after total knee arthroplasty for evaluation of contralateral knee pain. Plain radiographs of the left knee incidentally suggested the possibility of tibial baseplate fracture despite minimal, expected postoperative symptoms. Subsequent computed tomography imaging demonstrated no confirmatory evidence of component failure or fracture. Malalignment and fatigue fracture are proposed etiologies of baseplate fractures. The presented case illustrates the importance of computed tomography imaging and clinical correlation when a diagnosis of baseplate fracture is suspected to avoid an unnecessary revision surgery.

Atraumatic Fracture of Cemented Vanguard Total Knee Arthroplasty Femoral Component

The authors report the case of an atraumatic femoral component fracture 10 years after primary total knee arthroplasty (TKA) with a modern cemented fixed bearing system. The patient, a 70-year-old man, had the complication without inciting trauma, and he subsequently had severe pain and disability. This rare mode of TKA failure occurred at the superolateral aspect of the femoral component's anterior flange. At the time of revision, no femoral osteolysis was seen and the backside of the prosthesis fracture fragment was found to be free of cement. To the authors' knowledge, this is the first case of femoral component fracture in a Vanguard TKA (Biomet, Warsaw, Indiana), and the first case of fracture in a modern cobalt-chrome alloy femoral component associated with aseptic cement debonding. Femoral component stress fracture is a rare but serious complication of TKA. Reports of femoral component fracture in early designs were attributed to geometric design flaws, whereas modern TKA designs appear to fail when ingrowth failure, aseptic debonding, or osteolysis result in inadequate bony support of the prosthesis. Careful attention to bone cuts in porous-coated uncemented TKA systems and proper cementing technique in cemented TKA systems may preclude this rare complication. In the case of severe osteolysis, early revision may prevent catastrophic implant failure. [Orthopedics. 2020;43(5):e476-e479.].

Bilateral Femoral Component Fractures After Primary Total Knee Arthroplasty With Cruciate-Retaining Femoral Component

A 69-year-old male presented with atraumatic bilateral femoral component fractures at different time intervals after simultaneous bilateral total knee arthroplasty using the cemented Biomet Ascent Knee System. The right and left knee implant fractures occurred 12 and 17 years after primary arthroplasty, respectively. This patient was notably tall (190.5 cm, 98th percentile) and maintained an active lifestyle before implant fractures. Sequential, bilateral knee implant fractures in a system with a previously acceptable track record suggest that biomechanics, patient characteristics, and surgical factors can significantly influence the risks for fracture of an implant.

Catastrophic Polyethylene Failure and Fractured Femoral Component in Modern Knee Arthroplasty Design: A Case Report

CASE

We report a 67-year-old gentleman who presented with a painful unstable knee. He had undergone a successful total knee arthroplasty 12 years earlier and was highly functional. He presented with a 10-month history of mild pain, instability, and gait alteration. During revision surgery, there was a loss of bony support, and a fractured femoral component was identified. He required constrained revision components for reconstruction and made an uneventful recovery.

CONCLUSIONS

Fractured femoral components are rare complications of modern primary total knee arthroplasty. Loss of bony support in critical areas of high loading will inevitably lead to catastrophic component failure.

The mechanical response of a polyetheretherketone femoral knee implant under a deep squatting loading condition

The current study was designed to investigate the mechanical response of a polyetheretherketone-on-polyethylene total knee replacement device during a deep squat. Application of this high-demand loading condition can identify weaknesses of the polyetheretherketone relative to cobalt-chromium. This study investigated whether the implant is strong enough for this type of loading, whether cement stresses are considerably changed and whether a polyetheretherketone femoral component is likely to lead to reduced periprosthetic bone loss as compared to a cobalt-chromium component. A finite element model of a total knee arthroplasty subjected to a deep squat loading condition, which was previously published, was adapted with an alternative total knee arthroplasty design made of either polyetheretherketone or cobalt-chromium. The maximum tensile and compressive stresses within the implant and cement mantle were analysed against their yield and fatigue stress levels. The amount of stress shielding within the bone was compared between the polyetheretherketone and cobalt-chromium cases. Relative to its material strength, tensile peak stresses were higher in the cobalt-chromium implant; compressive peak stresses were higher in the polyetheretherketone implant. The stress patterns differed substantially between polyetheretherketone and cobalt-chromium. The tensile stresses in the cement mantle supporting the polyetheretherketone implant were up to 33% lower than with the cobalt-chromium component, but twice as high for compression. Stress shielding was reduced to a median of 1% for the polyetheretherketone implant versus 56% for the cobalt-chromium implant. Both the polyetheretherketone implant and the underlying cement mantle should be able to cope with the stress levels present during a deep squat. Relative to the cobalt-chromium component, stress shielding of the periprosthetic femur was substantially less with a polyetheretherketone femoral component.

Fracture of the Tibial Baseplate 16 Years after Miller-Galante II Total Knee Arthroplasty

We report a rare case of tibial baseplate fracture of Miller-Galante II (MG II) prosthesis. We examine the factors that may cause such late fracture and review the literature on radiographic analysis and retrieval studies. A 76-year-old woman, who had undergone bilateral MG II total knee arthroplasty due to rheumatoid arthritis 16 years earlier, presented to our department with a 3-month history of left knee pain. Plain radiographs revealed severe distortion of the medial tibial component. During revision knee arthroplasty, we observed severe metallosis in the knee joint, polyethylene insert deformation, and posteromedial coronal baseplate fracture. After removal of the fractured tray, a bone deficit due to osteolysis was noted. The revision prosthesis (LCCK, Zimmer-Biomet) was implanted uneventfully. Four months after revision surgery, the patient was ambulating and had no complications. The implants on the right side had survived without complications for 17 years. We speculate that the primary causative factor of the fatigue fracture of the base plate due to loss of bony support most likely secondary to osteolysis was varus malalignment at primary implantation. This case highlights the importance of paying close attention to the correct alignment of each component at primary implantation.

Fracture of titanium nitride-coated femoral component after total knee arthroplasty

We report a case of fracture of a titanium nitride-coated femoral component 3 years after primary total knee arthroplasty (TKA). The fracture was at the medial condylar area just posterior to the medial peg of the femoral component. The backside of the broken medial condylar portion of the femoral component was devoid of cement. Debonding of the component is a possible cause of the stress fracture. To our knowledge, this is the first case report of the fracture of the femoral component manufactured from titanium alloy.

LEVEL OF EVIDENCE

IV.

Tibial baseplate fracture associated with polyethylene wear and osteolysis after total knee arthroplasty

INTRODUCTION

Fracture of the tibial baseplate following total knee arthroplasty is very rare given the developments in modern prosthesis design. Tibial baseplate fracture secondary to polyethylene wear, osteolysis and component malalignment in an elderly obese patient is reported in the present article.

PRESENTATION OF CASE

A 69-year-old woman had undergone total knee arthroplasty eleven years prior to presentation and reported nine months of chronic pain, which was caused by a neglected fracture of the baseplate.

DISCUSSION

We discuss the prevention of implant fracture after total knee arthroplasty and address the risk factors associated with this complication.

CONCLUSION

The present case emphasizes the importance of properly informing patients and encouraging them to report such complaints immediately to allow for early revision and prevention of component fracture, especially in patients with risk factors such as obesity and component, malalignment.

Fatigue fracture of tibial arthroplasty implant masked by contralateral knee arthritis

INTRODUCTION

The wear of polyethylene components is a well-recognised long-term complication of total knee arthroplasty.

PRESENTATION OF CASE

We present a case of fatigue fracture of a geomedic tibial tray 17 years after implantation. The symptoms were masked by primary osteoarthritis of the contralateral knee.

DISCUSSION

The mode of failure in this case differs from that most commonly reported in the literature in that it occurred late as the result of prolonged use, not due to implant failure, physiological factors, or surgical technique. The case also demonstrates the incredible 'masking' effect of arthritic knee pain.

CONCLUSION

This case highlights the importance to clinicians of keeping a high index of suspicion for prosthesis complications in patients with unilateral joint replacement with contralateral arthropathy.

Bilateral fatigue fracture of the femoral components in a cruciate-retaining cementless total knee prosthesis

This article reports a case of bilateral fatigue fracture of the femoral components in a cruciate-retaining uncemented total knee arthroplasty (TKA). A 75-year-old woman (height, 158 cm; weight, 72 kg; body mass index, 29.2) had undergone one-stage bilateral TKA for osteoarthritis 11 years previously at the author's institution. Surgery was performed using an uncemented Flexible Nichidai Knee. Equal tension of the collateral ligaments and normal mechanical axis were achieved during the primary procedure. The patient was an ardent lover of the game of badminton and had higher activity levels with daily playing. At 8 years postoperatively, she started complaining of mild pain in both knees. The pain gradually increased, and at 11 years postoperatively, she had difficulty walking. Anteroposterior radiographs showed narrowing of the medial joint space, indicating wear of the polyethylene insert. Lateral radiographs showed signs of broken implants in both knees. There were no signs of gross implant loosening or osteolysis. One-stage revision surgery was performed, and the knees were converted to cemented posterior-stabilized TKAs. At revision, the bilateral femoral components were found to be fractured at the junction between the trochlear flange and the medial condyle, anteriorly to the medial peg. The polyethylene insert showed mild wear at the medial middle portion. In the majority of case reports, stress fractures of the femoral component have predominantly affected the medial condyle, following uncemented implantation of fixed-bearing knees. In this case, failure of bone ingrowth in uncemented components, higher body mass index, and a higher athletic activity led to fatigue fracture of the femoral components.

FRACTURE OF THE TIBIAL COMPONENT IN TOTAL KNEE ARTHROPLASTY: REPORT ON TWO CASES

The authors report the rare occurrence of two cases of fracture of the tibial component in total knee arthroplasty. They review the literature and discuss the main factors that can cause failure of the implants.

Femoral component fracture due to osteolysis after cemented mobile-bearing total knee arthroplasty

A 58-year-old man with osteoarthritis in the left knee underwent a total knee arthroplasty with a New Jersey anterior-posterior gliding low contact stress mobile-bearing implant. All femoral, tibial, and patellar components were implanted with bone cement. Pain developed at 43 months postsurgery, and plain radiography revealed a vertical crack in the femoral component and osteolysis at the medial femoral condyle. The femoral and tibial components were revised, and the bone defect at the medial femoral condyle was reconstructed using an allogeneic strut bone graft. Microscope examination identified polyethylene particles with foreign body granulomatous reaction, and scanning electron microscopy revealed fatigue failure of the femoral component. Osteolysis due to polyethylene particles can lead to fracture of the femoral component after cemented anterior-posterior gliding low contact stress mobile-bearing total knee arthroplasty.

Catastrophic failure of 4 cobalt-alloy Omnifit hip arthroplasty femoral components

BACKGROUND

Femoral component neck fracture is an uncommon type of failure in total hip arthroplasty. We present a report on 4 retrieved cobalt-chrome femoral components that fractured at the neck, where we investigated the mechanisms of failure.

METHODS

The 4 retrieved implants were analyzed with regard to their macro- and microstructures and the fracture surfaces were examined using electron microscopy. The medical record of each patient was also examined for any history of complications prior to failure of the implant.

RESULTS

These fractures occurred immediately adjacent to the base of the modular head. Skirted modular heads were used in 3 of the 4 failed components. This constructs promotes corrosion. Cyclic fatigue-loading in combination with the material factors of course grain microstructure and extensive carbide precipitation along the grain boundaries were also identified as the cause of implant failure.

INTERPRETATION

Our findings suggest that a solution annealing step could be introduced into the manufacturing process to improve the microstructure of the cobalt chrome alloy. We also advise caution in using a skirted modular head in combination with a device of known suboptimum microstructure, for a greater margin of safety.

A rare cause for knee pain: fracture of the femoral component after TKR. A case report

We report the rare case of sudden knee pain due to fracture of the total knee replacement nine years after implantation. Fracture occurred because of subsequent osteolysis due to polyethylene wear.

Imaging of knee arthroplasty

Knee replacement surgery, either with unicompartmental or total systems, is common. The purpose of this manuscript is to review the appearance of normal knee arthroplasty and the appearances of complications such as infection, polyethylene wear, aseptic loosening and particle-induced osteolysis, patellofemoral abnormalities, axial instability, and periprosthetic and component fracture. Knowledge of the potential complications and their imaging appearances will help the radiologist in the diagnostic evaluation of the patient with a painful knee arthroplasty.