Surgical technique guide i. Implants ii. Systems 1. Surgical material 2. Surgical approach I 3. Application I 4. Surgical approach II 5. Application II 6. Osteotomy 7. Finishing

Intramedullary fixation Stabilization of a single cut / large gap osteotomy with a locked intramedullary nail. Possible osteotomy sizes from 0.25 to 6.00 mm. A fracture model is also possible. Technology The RatNail system is a locked intramedullary nail made of medical grade stainless steel 1.4441 (316L). The implant is available in two standard sizes (depending on femural length) allowing for osteotomies from 0.25 to 6.00 mm. The pin driver for insertion of the locking pins is an integral component of the pin design and shears off once sufficient torque is applied. The locking pin is designed...

RatNail ii. Systems The RatNail system can cover single cut osteotomies up to large bone defects within the femur. RatNail with 0.25 mm osteotomy RatNail with 6.00 mm osteotomy

RatNail 1. Surgical material Implants: - 1x RatNail - 2x RatNail locking pins Implant specific instruments: - 1x RatNail aiming device - 1x Saw guide 0.44 mm RIS.322.110 RatNail aiming device XL Instruments: - 2x hand drills - 1x Accu Pen 6V+ Consumables: - 1x 0.71 mm Drill bit - 1x 0.44 mm Gigly wire saw, 0.50 m - 1x 1.00 mm Centering Bit - 1x 21 G needle, length > 45 mm - 1x Vicryl suture 3-0 - 1x Polyamid suture 3-0 - 1x Reamer 1.65 x 30.50 mm - 1x Drill Bit 2.00 mm

RatNail 2. Surgical approach I Positioning Rat in dorsal position.

RatNail 2. Surgical approach I Positioning The knee is bent according to illustration.

RatNail 2. Surgical approach I Anterior approach Longitudinal skin incision over the knee from the distal third of the thigh to the proximal third of the lower leg.

RatNail 2. Surgical approach I Longitudinal incision along the medial side of the patellar tendon.

RatNail 2. Surgical approach I Lateral dislocation of the patella to expose the knee joint.

RatNail 2. Surgical approach I Position of the intercondylary entry point on the femur.

RatNail 3. Application I Opening of the epicondyle Use the 2.00 mm drill bit to drill a hole into the intercondylar notch. According to the illustration start drilling with a 45 ° offset to the axis of the femur and continuously decrease the angle to 0° offset (parallel with the bone axis). Make sure not to exceed 4.00 mm in depth for the drill hole ! Verify the orientation of the longitudinal axis and keep the drill bit right between the two condyles of the medullary cavity and parallel to the bone axis.

RatNail 3. Application I Proximal opening of femur Use the 1.65 mm reamer to ream the medullary cavity. Again make sure that the orientation is central to the medullary cavity and parallel to the bone axis ! Open the femur proximally with a 21G needle > 45 mm, to prepare the insertion of the threaded tip of the RatNail.

RatNail 3. Application I Insertion Insert the RatNail under continous rotation until the notch at the distal end of the RatNail is flush with the epycondyle. Make sure to apply smooth axial pressure during insertion.

RatNail 3. Application I RatNail in situ.

RatNail 4. Surgical approach II Positioning Rat in prone position.

RatNail 4. Surgical approach II Anterolateral approach Longitudinal skin incision along the femur from the hip joint to the knee.

RatNail 4. Surgical approach II Small medial incision of the fascia lata and blunt preparation of the muscle below. M. vastus lateralis and M. biceps femoris are split and M. tensor fasciae latae is lifted to expose the full length of the femur preserving the sciatic nerve. Circular preparation of the femur at the area of the planed osteotomy.

RatNail 5. Application II Assembly Mount the aiming device to the RatNail. Pay special attention to the final position of the aiming device. Make sure there is no gap between the RatNail adapter flanch and the inner surface of the aiming device (marked in red). Orientation of the aiming device Position the aiming device anterolaterally to the femur

RatNail 5. Application II Interlocking of the RatNail Starting with the more proximal interlocking position use the 1.00 mm centering bit to prepare for drilling. Maintain the orientation of the aiming device and drill the first interlocking hole with the 0.71 mm bit. The countersinking as well as the drilling should be done by hand without the use of power tools ! Carefully apply the RatNail locking pin via the aiming device and bring it into its final position by turning it into the RatNail under continuos axial load. The locking pin drive shaft shears of as soon as the interlocking torque is...

RatNail 6. Osteotomy Performing the osteotomy Attach the 0.44 mm saw guide on the lateral side of the aiming device and create a defined gap by using the Gigly saw (sufficient irrigation !) Start sawing by keeping your hands close together. With progressing saw depth increase hand distance to avoid high forces. To ensure circular cutting of the bone repeat the sawing procedure on both sides of the aiming device

RatNail 6. Osteotomy Accomplishing the osteotomy Disconnect the shaft of the RatNail at the groove (marked red) by bending the aiming device carefully to the side while holding the leg.

RatNail 7. Finishing Wound closure Lift the M. quadriceps gently over the femur to its original position. Use vicryl suture 3-0 to close the fascia lata and polyamid suture 3-0 for the skin.

RatNail 7. Finishing Wound closure To reconstruct the medial ligament use vicryl suture 4-0 on the patellar tendon and the fascia lata.

RatNail 7. Finishing Wound closure Skin suture with polyamid suture 3-0.

RatNail Hazards and legal restrictions Scientific editor: Illustrations: Design and layout: In collaboration with: Hazards Katharina Schmidt-Bleek, Germany Agnes Ellinghaus, Germany Sandra Wissing, Switzerland Romano Matthys, Switzerland Julius Wolff Institut and Center for Musculoskeletal Surgery Charité-Universitätsmedizin Berlin, Germany Great care has been taken to maintain the accuracy of the information contained in this publication. However, the publisher, and/or the distributor, and/or the editors, and/or the authors cannot be held responsible for errors or any consequences arising from...