week 4

It is a normal week that has been split into four surgery days and one clinic day. As mentioned previously, Dr. Cross only deals with hip and knee cases, so most surgeries I have seen this week are primary total knee replacement and primary total hip replacement as usual. Every day there was at least one case for revision due to either dislocation of the prosthesis or severe infection. All of those cases are transferred from other doctors, and Dr. Cross still maintains his record of zero revision case for his own primary replacement surgery. On Monday, there is an infection case that patient suffered miserable pain on the lateral side of hip caused by the metal debris in the surrounding tissues. The metal-metal friction between the prosthesis has been happened for years since the patient’s medical report in 2012 clearly indicated that cobalt/chromium concentration in the blood is more than 7 times higher than normal. Dr. Cross took out the femur part of prosthesis that had been dislocated due to the bone cement fracture and replaced that with a titanium alloy one with much longer stem to be anchored within the femur.

On Tuesday I attended a meeting hosted by biomechanical engineering team. Dr. Timothy Wright is directing a project studying how would distal femur cutting height in total knee arthroplasty impact patent knee flexibility. There has been sufficient preliminary research studying the impact of the cutting height on the knee extension and coronal plan laxity, but limited information does doctor know about effects of distal femur resection on the knee rollback which is essential for patient daily activities such as stairing and jogging. The entire team is divided into two teams that focus on biomechanical studies and computational modeling separately. Based on my experience in the O.R. and conversation with doctors and technicians, THR surgery has been very close to perfection as most patients can stand up and walk within 24 hour of surgery and fully recovered in about three weeks. On the other hand, TKA usually takes a lot longer for patients to be comfortable with the prosthesis and restore the ability for daily activity, not even to mention the pain management and tough physical therapy every patient has to go though. Hope more research like such biomechanical engineering projects would improve the recovery process and benefit the patient.

Wednesday comes my favorite part of immersion program the clinical day.  Dr. Cross usually meets over 50 patients on his clinical day which means he has to work straight up for over 10 hours.  It is a great opportunity to learn from each case. Most patients have severe arthritis problems based on X-ray images analysis. In a lot of cases we saw bone-on-bone contact in knees or hips which indicate the complete wear out of cartilage. Dr. Cross usually recommends surgery for such situation if patients have already tried injections, physical therapy, and anti-inflammatory drug administration. For milder cases, Dr. Cross often recommends injections to alleviate the pain. There have been two types of injection I have seen: cortisone is classified as anti-inflammatory steroid that can relieve the pain for three months in over 50% cases; synvisc/halynonic acid is a synovial fluid component that can improve the joint lubrication over a year for three successive injections within three weeks.

Since the July 4^th weekend is coming, most members in Dr. Cross’s team take off on Thursday afternoon. In a relatively short week, I have observed over 10 knee and hip surgeries in the O.R. and seen over 50 patients in clinic. A lot of knowledge in orthopedics has been instilled and I am looking forward to start my own research soon.