Current variability in the assessment of component position for the unhappy knee replacement.

Introduction: Total knee arthroplasty (TKA) has a success rate of 80-90%, but despite this encouraging figure a painful TKA can be a source of dismay for patients and surgeons. Computed tomography (CT) scan has been developed as a tool to collect data in the analysis of TKA component placement. Protocols used to collect such data exist in orthopaedic and radiology practice with little standardization and significant variation. The aim of this review article was to evaluate such variability by sampling a series of protocols from a range of different radiology practices within NSW, Australia in a case-based manner and to then compare them against any literature standards.

Methods: The literature was surveyed for existing CT scan protocols used in TKA assessment. These were then compared with a series of metropolitan and rural radiology firms across the public and private sectors in NSW, Australia.

Results: Considerable variability exists between current protocols across NSW, Australia, which differ with proposed literature standards.

Conclusion: Variabilities encountered when comparing the different scanning protocols in use for the assessment of TKA constitute a large potential source of error in the analysis of TKA component positioning. The reliance surgeons place on such analyses suggests the need for an established scanning protocol with an incorporated grading system and standardized values to allow reproducible data to help assess and predict TKA function.