Week four - Jenny Puetzer

My fourth week of summer immersion was all about my research project. For my research project I will be assisting with a large study HSS is conducting to determine if MRI can be used to diagnosis and observe healing in meniscal tears. I spent the end of the third week preparing for this week by learning with another resident how to do dissections of sheep knees. Then this week was the time zero time point for the experiment. Tuesday I assisted and observed the surgery of 5 sheep knees in which they preformed an osteotomy of the chondyles to cut a tear in the middle of the medial meniscus. On Wednesday and Thursday I spent half of the day observing and learning how they do the MRI scanning of the sheep knee. It takes them about an hour and a half to scan one knee during which time they take images at many different planes. Then after scanning they are able to use a binary code system to reconstruct the meniscus and produce a 3D heat map of the meniscus. It was very interesting to actually be able to see the sutures in the meniscus during scanning. I spent the other half of the day on Wednesday and Thursday dissecting the sheep knees and preparing them for histological and mechanical analysis. A resident and myself worked together to dissect the sheep knees, take pictures of every part of the knee, record grades for wear and tear of the surrounding cartilage, take biopsy, and prepare the meniscus and biopsy plugs for histology or mechanical testing. It felt great to get involved with some research and made me realize how much I really do love performing research.

Thursday night and all day Friday I spent in the OR observing eight different surgeries. They were very long days but extremely interesting. Thursday I got to observe a total knee replacement. It was a very interesting case in which the patient had a high velocity break to the patellar plateau a few years back and now the plates put in place to help the break heal had broken. Dr. Rodeo had to first go in and find all the screws from the plate and remove them. He then went in on the side under the patella and cut out the menisci. Then started the real banging and pounding. The group of surgeons worked for around an hour to saw off the ends of the femur and tibia and then drill in large holes down the shaft of the bones for the knee replacements. Due to the poor quality of the bone from the earlier high velocity accident it was determined a sleeve and cement would have to be used to properly secure the knee replacement. This was a very interesting surgery to observe and especially interesting to see so much of the inside of the knee.


Friday I saw several rotator cuff repairs and menisectomies, however the most interesting surgery I saw was a femoral osteotomy. As I explained in an earlier blog an osteotomy is when the bone is cut and expanded to create a gap in the bone which is then packed with bone graft. This cut allows for lengthening and realignment of the bone which then helps to relieve pain in the knee by redistributing the load. The patient for this procedure was a 30 year old male who had been in a car accident when he was 10. They believe this car accident is the cause for the patient’s misalignment which has lead to a very valgus stance and thus advanced arthritis on the medial side of the knee. So it was determined using x-rays of the entire leg from hip to ankle that by cutting the femur and then expanding it by 12 degrees they could bring the knee back to a center alignment and thus relieve the patient from increased arthritis pain. It was very interesting to watch as the femur was sawed open, examined to determine the right angle and length of the cut, cranked open slowly to 12 degrees, filled with a bone graft, and then secured with a plate and screws. It was especially exciting to see in the end the change in alignment of the leg.