Objective: The goals of a tissue-preserving minimally invasive approach to the hip are to allow early short-term recovery, achieve hip joint stability, minimize muscle strength loss from surgery, spare the peri-articular soft tissues, and allow unrestricted motion in the long term.
Indications: Hip arthroplasty in patients with no pre-existing hardware, with a sufficient space between the acetabular rim and greater trochanter; management of subcapital femoral fractures in older patients.
Contraindications: Protrusio acetabuli. Joint stiffness. This is the main concern when undertaking the superior capsulotomy. Stiffness may result from bone causes, including ankylosis, large osteophytes, bone bridges etc., extra-articular retraction of surrounding soft tissues with capsular contracture of both ligaments and muscles, or a combination of bony and soft tissues causes, resulting in limited adduction. Indeed, maximal adduction is necessary to increase the distance between the apex of the greater trochanter and the superior acetabular edge. In the approach described in the present article, the real limitation is the impossibility to introduce a straight stem through the trochanteric fossa without weakening the trochantericarea. If adduction is restricted, excessive lateralization of the femoral stem would result in postoperative pain and discomfort, especially as we advocate immediate full weight bearing. Even though patients fare better when the trochanteric area is intact, many types of stem such as the GTS (Biomet), or stem Microplasty (Biomet) or even stem Parva (Adler Ortho) may pressurize the internal bone of the trochanteric structures. Therefore, these stems may be implanted in maximal hip adduction. This is the case in coxa profunda or coxa vara, which require more invasive and destabilizing surgical approaches.
Surgical technique: Lateral position, 5-8 cm incision from the tip of the greater trochanter, identification and transaction of piriformis tendon. Anterior mobilization of the gluteus minimus and exposure of the trochanteric fossa. Removal of the superior portion (bone block) of the head and neck, and preparation of the femoral canal. Preparation of the acetabulum. Complete muscle relaxion is helpful to proceed to satisfactory trial reduction.
Postoperative management: Patients may progress to motion and weight bearing without restriction.
Results: From April 2009 to December 2010, the first author operated on 463 patients, 275 for osteoarthrosis of the hip, and 188 for subcapital fractures of the femoral neck. Thereof, 375 (75 %) patients could walk with full weight within 6 h from the operation, and climb stairs 24 h later with low loss of blood, and rapid recovery.