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Thomas S. Thornhill, MD
First Session
Moderator: Thomas S. Thornhill, MD

David V. Cashen, MD Kevin Raskin, MD
Press-fit Components in Irradiated Hips with Metastatic Periacetabular Disease
David V. Cashen, MD
Advisor: John Ready MD
Discussor: Kevin Raskin, MD

Dr. Cashen performed a retrospective review to evaluate the survival of uncemented acetabular fully porous-coated implants and uncemented femoral components in the setting of irradiated hips for primary or metastatic disease. A total of nineteen patients were identified from a review of seven years of Dr. Ready’s database that were treated with THA with pre-operative pelvic irradiation. The mean survival of this population was 21 months. On follow-up, no components were loose, one failed secondary to septic arthritis and one had recurrent dislocation. There was a mean improvement in the Harris Hip Score of 44.2. Those with less cgray of exposure had better scores. Dr. Cashen noted that his small sample size limits the conclusions that can be drawn from this study.

Dr. Raskin commented that the week prior to this presentation, he had been at a national meeting where this very topic was being discussed. He noted that this research is particularly important for patients with metastatic breast cancer since they are living longer (secondary to improved chemotherapy) and tend to have less radiation to the pelvis. He noted that Dr. Cashen’s project was a “brave attempt” to identify a population that would benefit from total hip arthroplasty with biological fixation. He did note though that a major issue with this is cost – as trabecular implants are very expensive, some argue that using them in a patient population with a short life expectancy is not cost effective. A lively discussion ensued with the overall feeling that further research would be needed to look more critically at defining failure of the components and analyzing the economics (with consideration of the quality of life of the patient) of biological fixation in this population.

Jeffrey S. Zarin, MD Daniel Estok, MD
Claw Plate Fixation of The Greater Trochanter In Revision Total Hip Arthroplasty
Erik Spayde, MD
Advisor: Paul Glazar, MD
Discussor: Mark Vrahas, MD

Complications related to the greater trochanter in total hip arthroplasty has remained a complex and unsolved problem area in orthopaedics. Dr. Zarin detailed the history of trochanteric osteotomy in THA, reviewed the many techniques that have been employed to provide fixation of the greater trochanter, and provided examples of their complications. Dr. Zarin’s project sought to analyze the utility of a new anatomic claw plate that had been developed by Dr. Burke in response to the unacceptably high failure rates of the prior techniques of trochanter fixation. Through a retrospective study of thirty-one patients treated with a trochanteric claw plate in revision THA, Dr. Zarin looked at both clinical and radiographic outcomes with an average of 2.2 years of follow-up. The Harris Hip Score was 44 in this population pre-operatively and improved to 89 post-operatively. Twenty-four of the patients had a Trendelenberg gait (and some could not walk) pre-operatively while none of them had a Trendelenberg gait post-operatively and all were ambulatory. Pain decreased from 29 to 3. No patient had evidence of functional non-union. Dr. Zarin concluded that this plate is effective in improving functional outcome in this population and is a useful tool in revision total hip arthroplasty.

Dr. Estok acknowledged the complexity of the greater trochanter fixation for the revision arthroplasty surgeon. He pointed out that it would have been useful to detail the rehab protocol utilized in this population. There was enthusiasm from other arthroplasty surgeons in attendance about the very positive outcomes of this study. A larger sample population with longer follow-up was recommended.

Nicholas J. Avallone, MD Sang-Gil Lee, MD
Sports Participation in Patients with Brachial Plexus Birth Palsy
Nicholas J. Avallone, MD
Advisor: Peter Waters, MD
Discussor: Sang-Gil Lee, MD

Pediatric orthopaedic surgeons are often challenged by questions from parents about how a disability or injury will affect their child’s future. At Children’s Hospital in Boston, Dr. Waters provides care to many families with children born with brachial plexus birth palsy (BPBP). He is frequently asked by parents what they can expect for their child in terms of participating in activities, particularly sports – both ability to participate and potential for injury. Recognizing that there is a paucity of research investigating the incidence and types of sports-related injuries sustained by individuals with disabilities, Dr. Avallone sought to understand the level of sports participation in young people with brachial plexus birth palsy and the safety of participation in sports for patients with this birth palsy. Through a questionnaire filled out by parents and their child, Dr. Avallone obtained data on the level of participation in sports for these children, number and types of sports, and history of injuries. Analysis of the data from the 85 questionnaires revealed that children with BPBP equally participate in team and individual sports as children without disabilities. There was no statistically significant difference in injury frequency or type. From his research, Dr. Avallone concluded that patients with BPBP are able to participate in and enjoy a variety of sports and do not appear to be at an increased risk of injury compared to the non-disabled population of children.

Dr. Sang-Gil Lee applauded Dr. Avallone for giving useful information to doctors that treat this population of children, as parents can be reassured that their children are not at an increased risk of injury and they should be encouraged to participate fully in life. One question Dr. Lee raised was if disability level correlated with injury (incidence and/or severity). Dr. Avallone found no association between these factors. Dr. Waters acknowledged the importance of this study for young people with BPBP, particularly in the U.S. where sports participation in young people is so important and the fear of being ostracized because of not being able to participate is very real.

Rajiv K. Sethi, MD Daniel Estok, MD
Macrophage Response to Conventional And Crosslinked Polyethylene. An In-Vitro Study Using Both Disks And Wear Debris.
Rajiv K. Sethi, MD
Advisor: Harry Rubash, MD and Arun Shanbhag, PhD
Discussor: Daniel Estok, MD

In one of only two basic science presentations in this year’s Thesis Day, Dr. Sethi reviewed his work in the area of wear debris-induced osteolysis and aseptic loosening prevention. Dr. Sethi studied the macrophage response to cross-linked ultra-high molecular weight polyethylene (XLPE) in comparison to conventional UHMWPE (CPE), as well as frequently used materials such as titanium-alloy and cobalt-chrome alloy. Human peripheral blood monocytes and murine macrophages were used as surrogates for cells mediating peri-implant inflammation and were cultured into custom designed lipped disks fabricated from the test materials to isolate cells. Culture supernatants were then collected at set times and analyzed for cytokines. Dr. Sethi showed that human monocytes from all donors varied in the magnitude of cytokines released when cultured on identical surfaces. The variability in individual donor responses to titanium-alloy and cobalt-chrome alloy may reflect how individuals respond differently to similar stimuli and perhaps reveal a predisposed sensitivity to particular materials.

Dr. Estok applauded Dr. Sethi for taking on the “alphabet soup of osteolysis mediators” and his attempt to address a very important problem for the arthroplasty surgeon and their patients. Osteolysis is a silent problem until it is very late in its course and a failure occurs. Work like Dr. Sethi’s aims to find ways of identifying which patients are going to be at risk of developing osteolysis and intervene earlier to prevent failure. Dr. Estok wondered if we could use the human response to various materials shown in the lab to determine the need and frequency for follow-up for a given patient – understanding what their response to a material might be will enable surgeons to develop a logical timeline by which to follow each patient and prevent the occurrence of catastrophic failure.