Minimally invasive approaches in total hip arthroplasty.

The success of operative treatment depends on a quick recovery of limb function. Every injury to a muscle or its attachment is associated with decreased muscle strength and disturbed proprioception, which impedes functional recovery. Minimally Invasive Surgery (MIS) is defined as a surgical technique performed through a short skin incision to avoid injury to muscles and tendons. The advantages of MIS over the classic technique in Total Hip Arthroplasty include: faster recovery, shorter rehabilitation and hospital stay, decreased blood loss, less pain and a shorter scar. The anterior approach to the hip, first described by Robert Judet in 1947 as a modified Smith-Petersen approach, follows the principles of MIS. Other approaches advertised as minimally invasive (posterior, lateral, or double incision approach) are associated with muscle and/or tendon injury. Therefore, they should be referred to as Less Invasive Surgery (LIS). Complications of THA performed with the MIS technique occur most often in women with osteoporosis, above 65 years of age, or with a BMI of more than 32. The rate of complications doubles with surgeons performing less than 50 THAs per year. A special set of instruments facilitates implantation of the endoprosthesis and reduces the number of complications. The anterior approach allows for implantation of an endoprosthesis without damage to muscles and their insertions, reduces tissue damage and, more importantly, decreases the intensity of postoperative pain. Should complications occur, the anterior approach has the advantage of allowing simple access to the proximal femur by extending the approach distally, as in the Smith-Petersen technique. However, the technical challenges of MIS and the risk of complications warrant caution.