Minimally Invasive Total Hip Arthroplasty

Total hip arthroplasty (THA) is one of the most reliable procedures that can provide shortterm high clinical success rates and long-term durable outcome. The surgery has been developed for more than 40 years and most of the clinical practices are standardized for the patient care. In the past, THA had been done by making a wound about 25 cm in length. Many surgeons believed that big wounds should be the standard approach for THA because the surgery is a big surgery and could only be reliably done with big wounds. In recent 10 years, this concept of “big surgery-big wound” has been challenged in many fields of surgery. Taking the arthroscopic ligament reconstruction surgery or laparoscopic cholecystectomy surgery as the examples, many surgical procedures can now be safely and adequately performed by the minimally invasive (MIS) approaches. Although impossibly be done by an arthroscopy, the surgical approaches for THA have been adopting the concept of MIS and modified by many surgeons. However, the definition of a MIS-THA is not as straightforward as the words meanings. Based on the incision length, it is generally agreed upon that an incision less than 10 cm can be defined as MIS-THA. However the MIS can also be interpreted as less soft tissue trauma or less bone tissue trauma when doing the THA. The incision wound length then is not necessarily equal to the extent of tissue injury during the procedure. To date, the MIS-THA can be divided into two categories. One decreases the wound and muscle cutting and emphasizes the tissue repair through either a lateral or a posterior route. [1-4] The other spares muscle sectioning during the procedure through one [5,6], two [1,7-11], or multiple [12] incisions. The abridged incision methods minimize the incision length and can be extensile if difficulties are encountered during THA. The muscle sparing methods use tissue intervals for surgery but could be difficult if complications happened intraoperatively. In the literature, the complication rates are significantly higher in inexperienced, low-volume surgeons in the “learning curve” period for the muscle sparing techniques. [13] THA, however, is a reliable procedure and its clinical results should not be compromised by the surgical approaches. For those surgeons who start to learn the procedure, standard surgical approach with bigger wounds is strongly recommended. In the learning curve period of the MIS-THA, the incision should start from a standard length and then gradually reduces its size as the experiences accumulated. To master the MIS-THA surgical techniques, surgeons also need to familiar with the anatomy and different surgical approaches for THA. [14]