Week 2- Jonathan

This week, I was able to observe orthopaedic surgeries for for two full days. The first day, I watch Dr. Bostrom perform 8 hip and knee replacement surgeries. Seven of the surgeries were routine primary knee/hip arthroplasty surgeries and one was a revision of an existing knee replacement due to local infection. I found that the general procedure of either a hip or knee replacement surgery is very similar. After opening up the patient's joint cavity, the surgeon will use cutting tools specially designed for joint replacement surgery. Using them, the surgeon can cut off the existing bone and cartilage around joint and expose bone surfaces that the implants can be attached to. The surgeon will then instill test implants to the bone surfaces to find the correct implant size for the patient. Depending on the surgery, the surgeon will then fixate the implants into the bone using either bone cement or a press-fit technique.

The revision surgery was necessary because the patient had failed to take his antibiotics for a week, resulting is a severe infection in his knee. The revision surgery was similar to the primary surgeries with a couple of exceptions. Once the knee joint was opened up, the first task was to remove a considerable amount of inflamed tissue. Antibiotics were added to the solution used to clean the joint space throughout the entire surgery to help fight the infection. The tibial stem and femoral component of the knee replacement were removed, cleaned and sterilized before being re-implanted into the knee (A new tibial plastic condylar surface was installed). Bone cement used to fixate the implants was mixed with additional antibiotics to further fight infection.

The second day of surgeries, I followed Dr. Jerabeck. First, he performed a arthroscopic surgery to remove pieces of a damaged meniscus in the knee of a patient with a unicondylar knee replacement. This surgery was simple compared to the others I witnessed but very interesting because I could see the entire procedure from inside of the knee by way of an arthroscopic camera. I also watched Dr. Jerabeck perform a knee replacement and hip replacement surgery. Different than the surgeries I watched the previous day, these surgeries were performed using state-of-the-art engineering surgical aids to ensure the proper alignment of the implants. In the knee surgery, he used a device called Knee-Align. This device is attached to either the femur or tibia and is used to calculate where to cut on both bones so that the implant alignment is correct. The MAKO-plasty robot was used in the hip arthroplasty case. For this device the surgeon creates reference points on acetabulum and a specialized camera digitally re-creates the surface. As the surgeon bores into the acetabulum to find the bone surface to implant the acetabular cup, the system will inform him where to bore and will shut off if he bores too much or in the wrong place. The result is a properly bored hole with the correct alignment of the implant.


Overall it was a very interesting week. My project will be to research the use of cementless knee replacements in the field to determine if Dr. Bostrom should consider using them clinically.