Week 5: Alessandra Coogan

  Alessandra Coogan | Clinical Mentor: Dr. Scott Rodeo

Happy 4th of July! (in 3 days)

Last Friday, I had the opportunity to shadow Dr. Rodeo in the OR once again. One of my favorite parts of this immersion has been returning to the operating room because I always learn something new. Even the same case can have slight differences due to patient-specific nuances.

The first procedure was an arthroscopic lysis of adhesions in a patient who had undergone a total knee arthroplasty (TKA) six months earlier and continued to experience persistent pain. The goal was to investigate the source of the pain and remove any inflamed or scarred tissue that may have been contributing to the patient's symptoms. During the procedure, Dr. Rodeo debrided inflamed synovial tissue and collected several biopsy samples for pathology, although he was not worried. He mentioned that roughly 10% of patients continue to experience chronic pain following TKA despite technically successful implants, and he suspected this patient unfortunately fell into that category. One thing that surprised me was just how reflective the femoral titanium implant appeared through the arthroscope. It almost looked like a mirror... which made sense considering it had only been implanted six months earlier.

The next procedure was a shoulder arthroscopy with capsular release and core decompression for avascular necrosis of the humeral head. On the patient's MRI, the necrotic region appeared as a dark area within the humeral head (an example of which can be seen in Figure 1). During surgery, the team drilled a tunnel from the opposite side of the bone toward the necrotic lesion, allowing them to inject bone marrow aspirate harvested from the iliac crest to encourage revascularization. The affected region was unnervingly soft. The probe visibly deformed the underlying bone which signified structural integrity loss.

Figure 1. Avascular necrosis of humeral head (coronal view). Tissue necrosis appears black under MRI due to lack of blood supply to the bone (image source).

I also observed a partial meniscectomy for a very classic-looking bucket-handle meniscus tear (Figure 2). After removing the displaced fragment, Dr. Rodeo carefully debrided the remaining meniscal tissue to create a stable rim. Because the joint space was particularly tight, the surgical team frequently adjusted the position of the patient's foot and tibia to improve visualization and instrument access. One of the most interesting parts of the procedure was the discussion surrounding treatment decisions. Dr. Rodeo explained that:

• patients distribute loads across the knee differently. Some rely heavily on the meniscus to transmit forces across the tibiofemoral joint, while others naturally load the articular cartilage more directly. As a result, some patients tolerate partial meniscectomy remarkably well, whereas others experience accelerated degeneration following loss of meniscal tissue;
  
  
• age also plays an important role when deciding between meniscal repair and meniscectomy. In older patients, gradual degenerative changes have often already altered joint biomechanics, so removing a damaged portion of the meniscus may not substantially change how the knee functions. In contrast, removing meniscal tissue from a healthy teenager can significantly alter load distribution and increase the risk of long-term cartilage degeneration;

• patient's goals impact treatment decisions. While preserving the meniscus is generally preferred whenever possible, athletes often choose partial meniscectomy because it allows them to return to sport much sooner—typically within four to six weeks—whereas a meniscal repair may require approximately six months of rehabilitation and still carries a risk of failing to heal completely. Although the final decision belongs to the patient, balancing long-term joint preservation against a quicker return to activity is an important discussion that takes place before surgery.

Figure 2. Bucket handle meniscal tear.

I also observed a valgus-producing high tibial osteotomy (HTO) combined with a medial meniscus allograft transplantation in a 23-year-old patient. At nearly six hours, it was the longest procedure I have observed so far, but it was fascinating from start to finish. The surgery utilized a cadaveric medial meniscus, which was secured using anchor points and circumferential sutures to restore its attachment within the joint. The osteotomy itself was equally impressive, with the surgical team using patient-specific guides designed through BodyCAD software (Figure 3) to accurately position the cuts, hardware, and screws. It was remarkable to see how computer-assisted planning can improve the precision of such a complex reconstructive procedure.

Figure 3. Bodycad example. Terrifying.

The procedure was also a reminder of the physical demands of surgery. It was noticeably bloodier than many of the arthroscopic cases I had observed, and the continuous irrigation resulted in a surprising amount of saline accumulating on the floor throughout the operation. Despite standing for nearly six hours, the surgeons, nurses, anesthesiologists, and surgical technicians maintained an incredible level of focus and coordination throughout the entire case. I drew some sketches to pass the time (Figure 4).

Figure 4. Sketches of a madwoman. Sketches of the procedure, including the 3D model, transplant meniscus, how the meniscus was inserted, and attached.

On the research side, I made significant progress developing my Dragonfly segmentation workflow. I continued expanding the SOP that I have been building and am preparing to validate the workflow by comparing this segmentation method using an integrated plug-in called Bone Analysis Software against manually segmented datasets. This will provide a measure of segmentation accuracy before applying the pipeline to the experimental μCT datasets.