Modular Retractor for Hip Replacement Surgery

1. Modular Retractor for Hip Replacement Surgery Hassan Atassi (BME), AzniNabela Wahid (ME), Mohamed Osman (BME), NazihaLazim (BME/EE), ZulZolkaffly (EE) Department of Biomedical Engineering, Vanderbilt University - Nashville, TN Sponsors: Dave Martinez (Zimmer), Dr. Michael Christie (Southern Joint Replacement Institute) Device Design Purpose Problem Statement • Create a proof of concept modular retractor (Hibbs) that incorporates: • Alterable handle length & blade depth • Interchangeable handle types and tips • Ergonomic handle • Adipose tissue accessory Standard Hibbs Design a Modular Retractor to remove inefficiencies in the current retractor instrument in order to decrease the number of instruments needed in hip replacement surgery as well as to make hip surgery more efficient and safer. Modular retractor Background Modular Retractor • HIP REPLACEMENT SURGERY • Every year approximately 300,000 hip replacement surgeries occur in the United States. This number is expected to grow to 600,000 by 2015. • SURGICAL RETRACTOR • Separates the edges of a surgical incision or wound • Create a larger working area for the surgeon • Limit incision size • Available in variety of sizes and shapes: choice depends surgeons training/ patient • Cost for full retractor set : $4820 • Hibbs Retractor • Commonly used retractor in Hip Replacement Surgery • Simple design • Easy to prove proof of concept • Cost: $300 • PROBLEMS • Multiple versions of the same retractor for varying patient size • Limited Size Permutations: never exact fit to patient size • Decreased surgeon field of view (too large) • Ineffective & causes injury (too small) • Adipose tissue wraps around retractor making it inefficient • Handle is uncomfortable to grasp during long surgery • Average user changes hand position every 71 seconds .19” .40” 1.86” .17” 0.17” .64” 0.42” 3.92” 7.0” 5.54” 4.32” 0.19” 1.53” 3.9” Costs Design Cost Labor: $10,800 Prototype: $860 (Quick Parts) Plunger: $29.76 (JW Winco) Total: ~$11,700 Manufacturing Cost Modular Handle: ~$200 Body: ~$200 Modular Blade: ~$200 Adipose Accessory Attachment Mechanism Plunger Locking Mechanism (JW Winco) References http://www.wrongdiagnosis.com/h/hip_replacement/stats-country.htm http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2494409/pdf/annrcse01522-0032.pdf http://innomed.net/hip_rets_standard.htm#Anchor-Hibbs-46919 Acknowledgement Detachable Adipose Accessory TOP: Longest , BOTTOM: Shortest We would like to thank Dave Martinez, Dr. Michael Christie, Dr. Paul King, Dr. Joel Barnett, Mary Betty, The Sothern Joint Replacement Institute & St. Thomas Hospital for their support in the completion of this project.