7. Prevention of Epidural Adhesion using Novel Elastomeric Polypeptide Matrix
David H. Kim, MD
Advisor: Paul Glazer, MD
Discussor: Frederick Mansfield, MD

David Kim

Frederick Mansfield

Dr. David Kim used a rabbit laminectomy model to evaluate the effects of a new biomaterial (gel and membrane forms) in preventing postoperative epidural fibrosis. He studied sixteen rabbits who underwent two level discontinuous lumbar laminectomy, with one of two barrier materials implanted at one level, and the other level serving as an internal control. Analysis of gross and histologic sections at eight weeks postop revealed significantly decreased epidural fibrosis with both gel and membrane barrier materials compared to control. There was no adverse effecton wound healing noted.

Dr. Mansfield, in his discussion, noted that 5-10%of patients who undergo spine surgery will require reoperation, and epidural fibrosis is found in approximately 30%of these patients. Fat grafts, gel foam, and other methods have been used in an attempt to prevent this complication. Dr. Mansfield encouraged the future study of this biomaterial ’s effect of dural healing, and questioned the long-term effect on fibrosis in the operative site, once the biomaterial has dissolved.

8. Long-term Survivorship of Total Knee Arthroplasty Following Unicondylar Knee Arthroplasty Failure
David Golden, MD
Advisor: Scott Martin, MD
Discussor: William Tomford, MD

David Golden

William Tomford

Dr. David Golden presented his work analyzing the long-term outcomes (minimum ten years) for 32 total knee arthroplasty performed in 30 patients who had prior failed unicompartmental knee arthroplasty. His average follow-up time was 13. 2 years. Dr. Golden found that the mean survivorship of the UKA was 58 months in these patients, and failure was related primarily to loosening, malpositioning, or disease progression. In the TKA procedures, there was a 41%failure rate, primarily related to aseptic loosening or instability. Using Kaplan-Meier cures, Dr. Golden found an 81%survivorship of the TKA at 10 years, dropping to 55%at 15 years.

Dr. Tomford led the discussion, noting that UKA failure was related to technical problems in 65%of patients, and poor selection in 20%. He commended the study for its excellent long-term follow-up. He noted that based on these data, UKA is not conservative treatment and does not seem to lead to easier or more successful revision arthroplasty.