Orthopedic surgery expert witness advises on defective knee replacement

Orthopedic surgery expert witness advises on woman’s claim that a defective knee replacement component caused her injury. The plaintiff was diagnosed with osteoarthritis and patellofemoral malalignment. She underwent a total knee replacement using a system designed by the defendant. After a few months, the plaintiff was in pain, and another surgery was performed. A piece of the knee prosthesis — a polyethylene tibial insert — was replaced.

After the procedures she developed an infected right total knee prosthesis and underwent a prolonged and debilitating course of multiple extensive surgeries, hospital admissions, rehabilitation and prolonged courses of antibiotics and pain medications.

Question(s) For Expert Witness

1. What caused the plaintiff’s injuries?

2. Was the medical device defective?

Expert Witness Response

The plaintiff’s injuries were caused by a defective polyethylene tibial spacer that I removed during the subsequent surgery. I personally observed pitting and delamination of the tibial polyethylene component. The damage could be seen by the naked eye.

I am fully familiar with the appearance and surface texture of this product and its component parts. This type of pitting and surface changes are extremely unusual. These changes were diffuse and involved the entire surface of the polyethylene component.

Had the polyethylene component not been defective there would have been no need for subsequent surgery after the initial total knee replacement, and there would have been no post-operative complications.

The response to polymeric foreign body particles in the vicinity of a total joint replacement is now well known and well reported. The process is referred to as “particulate disease” and is due to the cellular response to the particles. The process can be activated by polyethylene wear debris. It is my opinion to a reasonable degree of medical certainty that the plaintiff’s symptoms were a consequence of such a cellular response to polyethylene debris.

The expert is an orthopedist and plaintiff’s treating physician/surgeon.