Modular Retractor for Hip Surgery Group 10 Azni

Modular Retractor for Hip Surgery Group 10: Azni Wahid Naziha Lazim Zul Zolkafly Mohamed Osman Hassan Atassi

Advisors Dave Martinez VP Sales Zimmer Mechanical Engineer Dr. Michael Christie Orthopedic Surgeon. Southern Joint Replacement Institute Holds Design Patents

What is a Retractor? �Surgical instrument by which a surgeon can: • actively separate the edges of a surgical incision or wound • hold back underlying organs and tissues �Allows for: • Smaller incision • Greater working area �Available in many shapes/sizes

Retractors-Hip Surgery �Wide Variety of retractors available for hip surgery • Choice depends surgeons training/ patient �Size of Patient �Point in time in surgery

Materials & Forces �Retractors are made of surgical stainless steel �Average Duration of Hold: 15. 5 Minutes �Forces: • Maximum: 48. 8 N • Average: 9 N

Retractor Prices Retractor Cost Aufranc Cobra Retractor $314 Ischium Retractor $825 Sofield Retractor $360 Femoral Elevator $975 Hohmann Retractor $422 Richardson Retractor $485 Hibbs Retractor $300 Average Cost Per Set $4, 820 To service 10 hip surgeries per day a minimum of 8 sets needed. Total cost: $38, 560

Example: Hibbs Retractor Model Overall Length Handle Length Blade Depth Blade Width Standard 8. 75” 8” 3” 1. 5” Medium 10. 75” 9. 75” 4. 5” 1. 5” Extra Large 14. 25” 13” 6. 5” 1. 5”

Issues with current retractor system 1. 2. 3. 4. Multiple versions of same retractor needed to do the same job because of varying patient size 1. 2. Increase cost Increase Storage space 1. 2. Decreased surgeon field of view (too large) Ineffective & causes injury (too small) 1. 2. Adipose tissue wraps around retractor inefficiencies Hip retractors being used in knee surgery 1. 2. Average user changes hand positions every 71 seconds Results in abrupt movement of retractor blade increases chance for injury & length of recovery Limited Size Permutations: never exact fit to patient size Obese Patients Uncomfortable Handle

Solution: Modular Retractor �Characteristics • • Alterable Handle length & Blade Depth Interchangeable handle types and blades Ergonomic Handle Adipose blade accessory

Alterable Handle length & Blade Depth � We propose a mechanism in order to alter the handle length and blade depth to any potential need • Current Standards averages three version of a given retractor of various dimension • Our solution allows for much more �Customizable to exact patient dimension �Optimized surgical view �Ideal length to retract exact amount of tissue • 3 retractors 1 �Less number of tools �Potential Cost decrease

Ergonomic Handle �New handle design to optimize comfort • Potential for multiple handles to be designed in future based on user preferences

Interchangeable Handle types and tips � Various types of tips are used based on need of surgery & surgeon preference • Various tips can be manufactured � Surgical Staff (retractor user) have different perceptions of comfort • Various Handles Can be Manufactured � Example: • 5 tips + 5 handles= 25 retractors � Separating the two components instead of 25 allows for 10

Adipose Accesory � 31% of Americans are classified as ‘obese’ �Obesity rising by 2% per year � 3 -4 fold increase of obese patients requiring Hip replacement �Proposed Solution: • An additional accessory to be added to retractor when operating on obese tissue to handle the increase of adipose tissue

Putting it all together… �Proof of concept designed modeled with: • Interchangeable & adjustable tip • Interchangeable & adjustable handle • Adipose Accessory �Additional tips and handles can be designed in future

Modular Retractor – Hibbs retractor ADIPOSE BLADE Detachable adipose blade HANDLE Alterable Handle length & Blade Depth BLADE

Alterable handle length & blade depth : The mechanism 1) Unlock Slot/groove Body 2) 3) 4) Blade BODY Lock HANDLE BLADE

Detachable adipose blade: The mechanism

Future Work �Minor tweaks to locking mechanism �Determine Dimensions • Stress-Strain Analyss �Protoype