Total hip arthroplasty (THA) is one of the most successful orthopedic interventions performed today in terms of pain relief, cost effectiveness, and clinical outcomes.1 As a definitive treatment for end-stage arthritis of the hip, more than 330,000 procedures are performed in the Unites States each year. The number performed is growing by > 5% per year and is predicted to double by 2030, partly due to patients living longer, older individuals seeking a higher level of functionality than did previous generations, and better access to health care.2,3
The THA procedure also has become increasingly common in a younger population for posttraumatic fractures and conditions that lead to early-onset secondary arthritis, such as avascular necrosis, juvenile rheumatoid arthritis, hip dysplasia, Perthes disease, and femoroacetabular impingement.4 Younger patients are more likely to need a revision. According to a study by Evans and colleagues using available arthroplasty registry data, about three-quarters of hip replacements last 15 to 20 years, and 58% of hip replacements last 25 years in patients with osteoarthritis.5
For decades, the THA procedure of choice has been a standard posterior approach (PA). The PA was used because it allowed excellent intraoperative exposure and was applicable to a wide range of hip problems.6 In the past several years, modified muscle-sparing surgical approaches have been introduced. Two performed frequently are the mini PA (MPA) and the direct anterior approach (DAA).
The MPA is a modification of the PA. Surgeons perform the THA through a small incision without cutting the abductor muscles that are critical to hip stability and gait. A study published in 2010 concluded that the MPA was associated with less pain, shorter hospital length of stay (LOS) (therefore, an economic saving), and an earlier return to walking postoperatively.7
The DAA has been around since the early days of THA. Carl Hueter first described the anterior approach to the hip in 1881 (referred to as the Hueter approach). Smith-Peterson is frequently credited with popularizing the DAA technique during his career after publishing his first description of the approach in 1917.8 About 10 years ago, the DAA showed a resurgence as another muscle-sparing alternative for THAs. The DAA is considered to be a true intermuscular approach that preserves the soft tissues around the hip joint, thereby preserving the stability of the joint.9-11 The optimal surgical approach is still the subject of debate.
We present a male with right hip end-stage degenerative joint disease (DJD) and review some medical literature. Although other approaches to THA can be used (lateral, anterolateral), the discussion focuses on 2 muscle-sparing approaches performed frequently, the MPA and the DAA, and can be of value to primary care practitioners in their discussion with patients.
Case Presentation
A 61-year-old male patient presented with progressive right hip pain. At age 37, he had a left THA via a PA due to hip dysplasia and a revision on the same hip at age 55 (the polyethylene liner was replaced and the cobalt chromium head was changed to ceramic), again through a PA. An orthopedic clinical evaluation and X-rays confirmed end-stage DJD of the right hip (Figure). He was informed to return to plan an elective THA when the “bad days were significantly greater than the good days” and/or when his functionality or quality of life was unacceptable. The orthopedic surgeon favored an MPA but offered a hand-off to colleagues who preferred the DAA. The patient was given information to review.
Discussion
No matter which approach is used, one study concluded that surgeons who perform > 50 hip replacements each year have better overall outcomes.12
The MPA emerged in the past decade as a muscle-sparing modification of the PA. The incision length (< 10 cm) is the simplest way of categorizing the surgery as an MPA. However, the amount of deep surgical dissection is a more important consideration for sparing muscle (for improved postoperative functionality, recovery, and joint stability) due to the gluteus maximus insertion, the quadratus femoris, and the piriformis tendons being left intact.13-16