Minimally invasive total hip replacement is the goal that joint surgeons have been exploring. the emergence of SuperPATH has truly shown us the coming era of minimally invasive total hip replacement. The incision length is 6cm~8cm; it does not need to cut the external rotator muscle and is accessed through the gap between the plow and gluteus minimus muscles, preserving almost all the muscle functions around the hip joint; almost the complete joint capsule is preserved; no surgical dislocation is required during the surgical operation (no extreme rotation and distortion of the limb is caused during the operation); the operation can be completed by 2 people, the main surgeon and the assistant. The technique was pioneered by Dr. James Chow of St. Luke’s Medical Center in Phoenix, Arizona, USA. (St. Luke’s Medical Center, Phoenix, Arizona, USA). The SuperPATHTM approach retains all the advantages of the standard posterior approach; it can be further extended and easily converted to a standard posterior approach. The approach is easy to learn and gives the surgeon complete freedom intraoperatively. Surgical procedure: Accurate preoperative template measurements require good quality standard pelvic and hip radiographs. Note: Preoperative template measurements are for estimation purposes only. The final size and position of the prosthesis is determined intraoperatively. 1. Patient position: The patient is placed in a standard lateral position with the operating table height adjusted to a comfortable position for the operator. The technique does not require maximum internal retraction of the lower extremity, so it is not necessary to offset the patient’s position to the anterior edge of the operating table. It is preferable to maintain the patient’s position by applying a fluoroscopic baffle brace, placed in the following positions: 1), pubic symphysis; 2), sacrum; 3), chest level, under the breast; 4), scaphoid C-length nail; to ensure proper pelvic rotation position, the hip is tilted slightly posterior. The affected hip is flexed at 45° and the affected limb is internally rotated 10° to 15° so that the greater trochanter is facing upward. The foot of the affected limb is placed on a padded Mayo surgical tray, and the affected limb is gently tucked in so that the weight of the limb will balance the hip joint and allow for neutral pelvic rotation. This is the “main position” of the surgical technique, and most of the operations are done in this position. 2.Soft tissue dissection: The incision starts from the tip of the greater trochanter and extends 6cm ~ 8cm proximally, and is cut along the femoral axis to the fascial layer of the gluteus maximus muscle. The fascia of the gluteus maximus muscle is incised with an electric knife, starting from the tip of the greater trochanter and extending along the main incision line. The surgical view of the main incision can be adjusted by flexion, extension, and internal retraction of the affected limb. The gluteus maximus muscle is separated with 2 pterygoid tip adjusters (P/N 20070038; angled pterygoid tip adjusters may also be used P/N 20070040). The capsule covering the gluteus medius is exposed and a very thin layer of capsule tissue is carefully incised along the posterior edge of the gluteus medius. The Hohmann retractor blade is placed at no more than 90° to the wound in the gap between the gluteus medius and gluteus minimus. It may be necessary to release the short external rotator groups, especially in the tight hip area. During the learning process, the incision is minimized at the beginning to release fewer short external rotators; eventually reaching no release of short external rotators, with the possible exception of the pear-shaped muscle. 3. Capsule exposure: Assist in abducting and externally rotating the hip (elevating the knee with the foot still maintained on the Mayo surgical tray cart) to reduce the tension on the external rotators.1 Place the Cobb aligner posterior to the gap between the pear tendon and the gluteus minimus, where the sciatic nerve will be protected by the external rotators. This is then replaced with a blunt Hohmann retractor placed between the posterior joint capsule and the external rotator, with the Hohmann retractor blade at no more than 90° to the wound and the 2 retractor handles parallel to each other. The knee joint is lowered to restore the “body position”. If the pear tendon is producing too much tension, it can be released under direct vision. 4. Capsulotomy: The posterior border of the gluteus minimus is gently pushed forward with the Cobb aligner to reveal the deeper capsule. The main incision with electricity in the joint capsule is cut. The joint capsule is incised with the electric knife in the direction of the main incision, and the rotor fossa is incised with a long electric knife tip to prevent bleeding around the base of the femoral neck. Make sure to prepare the entire saddle of the femoral neck and the greater trochanter with the electric knife intact. This area has many returning vessels that may cause bleeding, so it is better to over-prepare than under-prepare. The joint capsule is incised from the saddle of the femoral neck and extended proximally to the acetabulum for approximately 1 cm. Carefully subperiosteal the joint capsule acetabular rim attachment for 1 cm and extend it 1 cm anteriorly and posteriorly, limiting the stripping of this portion to only 1 cm in all directions; also have the assistant note any foot movement of the patient as the sciatic nerve is just 2 cm posteriorly. The joint capsule incision should be a simple straight incision so that it can be repaired at the end of the procedure as if it were a rotator cuff. The patient’s knee is elevated to reduce external rotator tension, and a Cobb aligner is placed intra-articularly between the posterior capsule and the posterior femoral neck, then replaced with a blunt Hohmann pulling hook placed anterior to the posterior capsule. The lower extremity is then restored to the “body position”. The blunt Hohmann retractor is repositioned in the anterior capsule in a similar manner. The joint capsule is marked for identification during repair, revealing the plow fossa, the apex of the greater trochanter, and the anterior femoral neck (saddle). 5. Femoral preparation: Femoral reaming and meduloplasty are performed with the femoral head intact, reducing the risk of fracture of the femoral neck. The assistant presses the knee joint to slightly pronate the affected limb and the saddle of the femoral neck is exposed to the incision. An open-ended reamer (P/NS prr00080 or 4700r09000; not included in the SuperPATH instrumentation) is used to access the femoral medullary cavity through the rotator fossa. A metaphyseal reamer (P/N ptmr0001) is used to widen the proximal opening and ensure that subsequent instrumentation is properly aligned and does not invert. To allow for easy insertion of the femoral medullary file, an appropriately sized Round Calcar Punch (P/NS 20070052, 20070053, and 20070054) and impact handle (P/N 8000010) can be used. The femoral neck is first opened and the knife is started from the reamer opening, creating a groove toward the acetabular rim. The assistants internalize the affected limb to obtain maximum exposure. The proximal middle femur is treated with a spatula (P/N 20071006) to ensure that the surface provides good cortical bone contact, promotes bone growth, and prevents settling and micromotion. 6. Medullary shaping: Depending on the size of the reamer-medullary file or medullary file used, the appropriate medullary file was selected for medullary shaping. Check the depth of insertion with the open file handle (P/N slbrohan; not included in the SuperPATH instrumentation) and measure the top of the open file relative to the tip of the greater trochanter at a depth of usually 15mm to 25mm, depending of course on the patient’s anatomy and preoperative leg length differences; a medullary probe can also be used to check and confirm (P/N 20071008) The depth of insertion. Once the final type of medullary file has been placed, the handle is removed and the femoral neck osteotomy is guided according to the medullary file. 7. Femoral head resection: The femoral neck is osteotomized in line with the surgical wound, the knee is elevated to allow mild hip abduction, and the femoral neck is amputated along the tip of the medullary file using a pendulum saw with a narrow blade. 8. Femoral head removal: Place a Stenograph pin (P/N 20070057) into the hard part of the femoral head, use the lever force of the Stenograph pin to rotate the femoral head to the maximum internal retraction position, then place a second Stenograph pin into the other hard part of the femoral head, leave the chuck of the electric drill at the end of the Stenograph pin and pull the femoral head out of the main incision. If the femoral head is difficult to remove, the first stylet is removed and the femoral head is rotated further into a more involuted position before another stylet is placed. The femoral head is allowed to continue to “walk” to the maximal adduction position until the round ligament is torn or can be cut by the electric knife. 9. Preparation of the acetabulum: The affected limb is placed in the “main body position” and two sharp Hohmann hooks (P/N 20073113) are placed in the axilla between the anterior and posterior acetabular lips and the joint capsule, respectively. The acetabulum and all soft tissues remaining on the acetabular labrum were removed under direct vision, and the foramen ovale artery was often present posteriorly. After soft tissue removal, hemostasis is achieved with an electric knife (a long tip is recommended). A zelpi retractor (P/N 20071004) is placed under the periosteum of the acetabular rim proximal to the incision and a Romanelli retractor (P/N 20071001) is placed in the distal joint. The combination of these automatic retractors will provide rotational stability and provide a space for the acetabular file and implant to be introduced into the joint. The sharp Hohmann pulling hook is removed at this time. 10. Percutaneous incision creation: With the affected limb still in the “subject position”, the assistant turns the tip of the bone hook (P/N 20071011) into the top of the medullary file and pulls the femur anteriorly. The aiming handle (P/N 20071009)/entry positioner (P/N 20070015)/Threaded Cup Adapter (P/N 20070013)/acetabular trial mold (P/N 20070146) is assembled on the acetabulum with the tip of the guide perpendicular to the patient’s torso; because the patient’s pelvis is tilted on the operating table, the rod of the guide is tilted 10° from the vertical. The rod of the guide is inclined 10° to 15° to the vertical line. A blunt Trocar (P/N 20070116) with a trocar (P/N 2007st20) is placed through the guide. A 1 cm horizontal incision is made at the site where the Trocar crosses the thigh. The blunt Trocar with trocar is inserted through this small incision and continued deeper 1 to 2 cm posterior to the femur until the blunt Trocar with trocar is visible through the main incision. The aiming handle (P/N 20071009)/entry positioner (P/N 20070015)/Threaded Cup Adapter (P/N 20070013)/acetabular trial mold (P/N 20070146) and the obtuse Trocar are removed and only the trocar is left in place. The orientation of the trocar can be easily moved by adjusting the limb. 11. Acetabular polishing: Place the Hex Acetabular Reamer (P/Ns PATHRM40 – PATHRM64, not included in the SuperPATH instrumentation) through the main incision using the Acetabular File Handle Reamer Basket Holder (P/N 20070048) with the appropriate size acetabular file. The rod of the acetabular file is inserted through the trocar and connected to the acetabular file in situ. Begin filing the acetabulum. 12. Cup placement: Threaded Cup Adapter is inserted into the acetabular cup apical hole and the cup is fitted through the aiming handle. The aiming handle provides 25° of anterior tilt when perpendicular to the patient and 40° of abduction when perpendicular to the ground. The acetabular cup is in the acetabulum and the aiming handle directly controls the position of the cup. A cup impinger (P/N 20071010) is placed through the trocar. Because of the patient’s tilted pelvis on the operating table, the rod of the guide is again tilted 10° to 15° from the plumb line. The cup impinger strikes the cup until it is firmly fixed. A sighting device (P/N 33330080) can be attached to the cup impinger. 13. Screw placement: Establish the acetabular screw fixation hole with a long trocar. Place a long drill sleeve through the sleeve and attach to the target fixation hole. Place a screwdriver through the long sleeve and measure the depth; screw in the appropriate length of screw and remove the screwdriver and long sleeve. Screw holes can be created in a similar way using a drill pipe and a stitching needle. In this way, the stitching needle is drilled until it reaches the bottom of the drill sleeve and continues on to create a 30 mm deep screw hole. Note: The Screw Drill (P/N 20071007) can only be used with the Long Drill Sleeve (P/N 20071012) and not with the Drill Tube (P/N 20071005) because the depth dimensions do not match. A screw holder can be placed through the main cutout to control screw orientation. Use ball joint screw up or straight screw up to connect the screw up handle, through the casing with and tighten the screw. 14. Trial mold repositioning: Select the appropriate femoral head and neck according to the amount of bone removed and the preoperative template measurements. Adjust the position of the limb and install the metal trial mold neck to the medullary file already in the medullary cavity of the femur. The trial mold femoral head (P/N apa02121- apa02154, or combination P/NS 41102800 – 41104800 and apa0tss3Capa0tsl3; not included in SuperPATH instrumentation) is mounted to the acetabular cup with the opening facing superiorly posterior. The blunt Trocar was inserted into the top of the medullary file and trial repositioning was performed to reset the trial neck to the trial head. During the resetting process, the operator pushes and pans the limb through the main incision under direct vision to control the limb, and the assistant controls the internal and external rotation of the hip by elevating or lowering the knee or foot. 15.Trial removal: The affected limb is in the “main body position”, and the assistant hooks the bone hook to the lateral side of the medullary file to pull the limb. Place the blunt Trocar tip into the upper hole of the trial neck; separate the two instruments against each other to dislocate the trial neck from the medullary file. Remove the trial neck and trial head, as well as the femoral medullary file. 16. Prosthesis assembly: Clean and dry the acetabulum and tap the cup liner into the acetabulum with the cup impinger (through the trocar) and the liner impinger (P/NS 20070023 – 20070025). The femoral stalk is installed and tapped. The depth of placement of the stem can be confirmed by measuring the distance from the Canal Feeler to the tip of the greater trochanter. Install the femoral head prosthesis (using a neck sleeve if a large diameter femoral head is selected) into the acetabular cup liner with the opening facing superiorly and posteriorly. Note: In order to properly assemble and tap the neck block, it is important to ensure that the neck block and femoral stem seat are clean and dry. Use an eccentric neck block impinger when installing the neck block. The blunt Trocar is mounted to the femoral stem and the neck block is mounted to the femoral head. The neck and head are cleaned and dried, and the limb is controlled by the operator pushing and translating through the main incision under direct vision as per the trial mold repositioning, and the assistant controls the internal and external rotation of the hip by raising or lowering the knee or foot. Joint stability was confirmed by checking the range of motion of the joint and the length of the limb. 17. Closure of the wound: The entire joint capsule is preserved and can be reconstructed almost as easily as closing the incision, starting from above and below when closing the joint capsule. If a release is done, the plastron can be re-sutured to the posterior border of the gluteus medius. The rest of the incision is sutured in the usual manner.