Tibial tray fracture in a modern prosthesis with retrieval analysis

Early Tibial Component Fractures in a Cementless, 3D-Printed, Titanium Implant

Fracture of the tibial baseplate in total knee arthroplasty is a rare occurrence, particularly in short- and mid-term follow-up. This case series documents the first known report in the literature of fatigue fracture of a cementless, 3D-printed, highly porous titanium tibial component. We recommend regular follow-up visits with radiographs to confirm adequate total knee arthroplasty component positioning and alignment.

Catastrophic Failure of the Tibial Component After Total Knee Arthroplasty: Fracture and Dissociation Between the Baseplate and Stem

Fracture of the tibial component can be a devastating complication after primary total knee arthroplasty. While fractures of the tibial baseplate have been reported, failure at the junction between the baseplate and stem has not been well-described. We present a 49-year-old male who developed progressively worsening left knee pain and an effusion 7-8 years after an index total knee arthroplasty. Radiographs revealed component subsidence and subtle asymmetry between the baseplate and stem. At the time of revision, the tibial component was found to be fractured at the junction of the baseplate and stem, with complete dissociation between the two pieces. Clinicians should maintain a high index of suspicion for catastrophic failure, as this rare phenomenon can be subtle on radiographs and requires close monitoring for signs of component subsidence.

Use of Real-World Data for Enhancing Model Credibility: Applications to Medical Device Development

Evaluating the credibility of computational models used in medical device development is increasingly important as medical devices become more complex and modeling takes on a more critical role in the device development process. While bench-testing based comparisons are common for assessing model credibility and have many advantages, such as control over test specimens and the ability to quantify outputs, the credibility assessments performed with bench tests often do not evaluate the clinical relevance of key aspects of model form (such as boundary conditions, constitutive models/properties, and geometries) selected when simulating in vivo conditions.

Real-world data (outcomes data generated through clinical use of a device) offer an opportunity to assess the applicability and clinical relevance of a computational model. Although real-world data are frequently less controlled and more qualitative than benchtop data, real-world data are often a direct assessment of a particular clinical complication and therefore of high clinical relevance. Further, real-world data have the potential to reveal failure modes not previously identified in pre-clinical failure modes analysis, thereby motivating testing advancements. To review the use of clinical data in medical device modeling, this paper presents a series of examples related to tibial tray fracture that incorporate varying levels of benchtop data and real world data when evaluating model credibility. The merits and drawbacks of the credibility assessment for each example are discussed in order to provide practical and actionable guidance on the use of real world data for establishing and demonstrating model credibility.

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.

Short-Term Tibial Baseplate Fracture After Total Knee Arthroplasty in the Absence of Osteolysis and Implant Loosening: A Case Report

CASE

The patient is a 62-year-old man with early tibial baseplate failure involving fracture and subsidence of the posteromedial metal implant, only 3 years after primary total knee replacement. Although this mode of failure is frequently observed secondary to polyethylene wear and osteolysis, this case was likely because of suboptimal tibial baseplate size and positioning with lack of cortical support that underwent accelerated fatigue, given the high activity level of the patient.

CONCLUSION

This case demonstrates rare sequelae of inadequate tibial coverage and cortical structural support of the baseplate. Tibial coverage is influenced by implant sizing, implant positioning, and variations in patient anthropometrics.