Technique

As the surgery is performed with the patient placed in a lateral position, it is crucial to provide stable support on the back and front of the pelvis. Part of a foot of the operating table is removed, so that the leg can be positioned dorsally in a hyper-extended position in order to expose the femur. The incision starts at the middle of the greater trochanter and extends to the iliac crest. The incision length is 5-8 cm long, depending on the size of the patient.

Incision

After the opening incision, the fat tissue is cut through passing downwards to the muscular tube of the tensor muscle. The sheath around the muscle is opened and the muscle is bluntly dissected, separating the muscle from the intermuscular septum to the neck of the femur. Retractors are placed on the femoral neck as well as on the femur to hold the muscles away from the surgical site and allow a clear view of the joint capsule. A T-shaped capsular excision is then made without.

Opening the joint capsule

Retractors are placed under the joint capsule, and the femoral neck is cut at the position determined during preoperative planning. We now insert a corkscrew into the head of the femur and the worn joint head is carefully removed.

The inside of the socket is now free and a special milling cutter is used to remove burs until the bone is has an evenly contoured surface. We usually use a layered titanium cup, pressing it firmly into the prepared acetabulum until the two surfaces interlock and stick together. It is important that the position of the cup is exactly right. To do this, we orient the titanium cup in alignment with the natural position of the acetabulum. Doing this correctly requires a lot of surgical experience.

Positioning of the leg to expose the femur

The leg is rolled back and placed in a special bag to ensure sterility. It is now important that the lower leg be positioned perpendicular to the floor. Retractors are then placed on both sides.

A fine file is inserted into the internal (medullary) canal of the femur. The canal is sequentially made larger by using stepwise bigger files until an optimum space to receive the implant stem with a perfect grip and length is achieved.

Insertion of the prosthesis takes into account the desired exact endposition. After the new joint head is brought together with the new joint cup on the pelvis, articulation is tested. When the joint is stable and moves freely, the joint capsule is closed and the muscles are layed back in position around the joint. Now just the connective tissue around the muscle and the skin need to be closed. Then the hip is as it was before the operation, except that it has a new joint.

The surgery is generally completed in about 45 minutes, being performed in an internervous plane without detaching muscles or tendons, and without resecting the joint capsule. To date, we have performed over 3000 MicroHip surgeries and have seen significantly fewer complications, as compared to open hip surgery. The recovery time is much shorter, the blood loss is less, and the 5-year results are clearly better than with “older” surgical techniques.