1. A prototype device was generated that meets most of the design objectives: The accuracy of pin placement has been facilitated in the current design through the stiffness of the device and its rigid connection to bone The reproducibility of pin placement has not yet been evaluated. The control of varus/valgus angulation and superior /inferior position has successfully been decoupled in this design. Internal/ external rotation and anterior/ posterior position are not addressed by the current design The existing prototypes have been fabricated with 3D printing using ABS which is highly porous and can not be sterilized for use in the OR Future directions include: Cadaveric simulation testing to assess accuracy and repeatability Addition of secondary aiming arm to decouple internal/ external rotation from superior/ inferior position Evaluation of alternate fabrication methods that are FDA approved for use in the OR The current project demonstrated the feasibility of creating a percutaneous hip pin guide which could facilitate the accurate, reproducible, and technically simple use of percutaneous techniques in the placement of a sliding hip screw Intertrochanteric (IT) hip fractures are common among elderly patients and are a source of significant morbidity, decreased mobility and loss of independence [1]. These fractures are commonly treated with surgery consisting of reduction of the fracture and fixation with a sliding hip screw. The sliding hip screw is installed over a guide wire which must be accurately placed from the lateral femur to the center of the femoral head. Positioning of the guide wire is typically achieved using a 10- 15 cm incision thru muscle and fascia to place an angle guide onto the femur. An alternative percutaneous (without incision) technique for pin placement [2] has been shown to have decreased blood loss and operative time [2,3,4]. However, this technique is technically demanding because it requires the surgeon to simultaneously control pin angulation and translation in two planes. The goal of this project is to develop a percutaneous hip pin guide to facilitate the minimally invasive technique for placing a sliding hip screw. Requirements include: Enable accurate and reproducible percutaneous placement of the pin into the center of the femoral head at the correct angle Decrease the technical demands of the procedure by uncoupling the steps in pin placement 1. Kaplan K, Miyamoto R, Levine BR, Egol KA, Zuckerman JD (2008) Surgical management of hip fractures: an evidence-based review of the literature. II: intertrochanteric fractures. J Am Acad Orthop Surg 16 (11):665- 673 2. Alobaid A, Harvey EJ, Elder GM, Lander P, Guy P, Reindl R (2004) Minimally invasive dynamic hip screw: prospective randomized trial of two techniques of insertion of a standard dynamic fixation device. J Orthop Trauma 18 (4):207-212 3. Ho M, Garau G, Walley G, Oliva F, Panni AS, Longo UG, Maffulli N (2009) Minimally invasive dynamic hip screw for fixation of hip fractures. Int Orthop 33 (2):555-560. 4. Cheng DC, Martin J, Lal A, Diegeler A, Folliguet TA, Nifong LW, Perier P, Raanani E, Smith JM, Seeburger J, Falk V (2011) Minimally invasive versus conventional open mitral valve surgery: a meta-analysis and systematic review. Innovations 6 (2):84-103. Accuracy and repeatability of pin placement were addressed by designing a guide that would be rigidly held to the femur using both the soft tissue of the thigh and pin fixation directly to the femur Placement of the pin was separated into four independent sequential steps: 1) varus/valgus angulation, then 2) superior/ inferior position, then 3) internal/external rotation, and finally 4) anterior/posterior position A conceptual sketch of a device that could accomplish both of these goals was then made. The sketch was then translated into a part in Solidworks (Dessault Systemes, S.A., Waltham MA) This part was then 3D printed yielding an initial prototype The initial prototype was subjected to simulation testing using a Sawbones model Insights gained from the simulation testing led to design changes which wre incorporated into the second prototype. X-rays of IT fracture before and after fixation Placement of guide on bone Solidworks part from initial prototype Simulation testing using 3D printed initial prototype Solidworks assembly of second prototype Conceptual sketch Percutaneous use of guide Fluoroscopic image during percutaneous pin placement