The Hype of Patient Specific Instrumentation in Total Knee Replacement

The Hype of Patient Specific Instrumentation in Total Knee Replacement

AAOS 2012

Patient-specific instrumentation in total knee arthroplasty provides no improvement in component alignment.
Author: Stronach et al.

Conclusion: We found no improvement in component alignment with decreased accuracy in tibial slope with the use of patient-specific instrumentation compared to traditional instrumentation during primary TKA. We cannot currently recommend the use of this technology due to no appreciable alignment benefit with an associated additional cost and resource utilization.

Patient-Specific Instrumentation in TKA required frequent surgeon-directed intraoperative Changes.
Author: Stronach et al.

Conclusion: In this prospective study patient-specific instrumentation (PSI) required frequent surgeon-directed intraoperative changes to improve component placement. Surgical experience was necessary to recognize and change PSI default surgical plans in a high percentage of cases. We would caution surgeons against blind acceptance of PSI-generated surgical plans.

Are patient-specific instruments justified for routine TKA? No!
Author: Healy

In 2012 there is insufficient evidence to justify using patient-specific instruments for routine TKA. Patient-specific TKA instruments can be defined as custom distal femoral and proximal tibial bone cutting guides which are manufactured based on three-dimensional images (CT or MRI) of the patient's knee. There is little data to support the assertions that patient-specific TKA instruments can improve TKA patient outcomes. Concerns regarding PSI include:

  • Increased time and cost for preoperative planning and imaging studies.
  • The fit of the tibial cutting block is not as predictable as the fit of the femur cutting block.
  • Reduced flexibility in altering bony cuts for unexpected problems.
  • Increased intraoperative cost for PSI when compared to standard TKA instrumentation. ...The efficiency of patient-specific TKA instruments has not been proven.

Patient-specific instrumentation for TKA; The future is now – Against.
Author: Vail.

While these concepts have considerable conceptual appeal, they are neither proven to be cost-effective nor consistently accurate in clinical use. The device has considerable traction in marketing circles. Patients are also fascinated by new technology, particularly technology that might remove the human error variable.

For a surgeon looking for a way to sell his/her practice the concept of marketing a total joint program around a “customized” approach has appeal. However, one can argue that such an approach would be disingenuous as it relates to this particular technology ...

The accuracy and efficiency of the technology is not proven in the published literature ... The success is ultimately determined by the skill of the surgeon at using the device ... One can now add to the equation the accuracy of the imaging, the accuracy of the custom block fabrication, and the proper placement of the block onto the patient. At present my conclusion is that the technology provides no value proposition for the patient, the surgeon, or the hospital.

2012 American Academy of Orthopedic Surgeons (AAOS) Meeting – San Francisco; select excerpts.

-JGM