Total Hip Arthroplasty-evolution and Current Concepts
J.V. Srinivas *, Mohan Puttaswamy Fortis Hospital, Bannerghatta Road, Bangalore, India
Abstract
Total hip arthroplasty (THA) has been designated as the Operation of the century. The past 3-4 decades have seen tremendous improvement in the patient outcomes, products and technology that has enabled all these changes to improve the quality of life of our patients with problems of the hip joint. We have reviewed the surgical approaches to the hip joint, the bearing surfaces, implant selection and their problems and complications in this chapter. We have also stated our approach and philosophy to have good outcome of THA.
Keywords: Approaches to the hip, Bearing surfaces, Cemented arthroplasty, Deep vein thrombosis, Dislocation of the hip, Total Hip Arthroplasty, Un-cemented arthroplasty, Wear.
* Corresponding author JV Srinivas: 154/9, Bannerghatta Road, Opposite IIM-B, Bengaluru, Karnataka-560076, Bangalore, India; Tel/Fax: 080-66214121; E-mails: [email protected], [email protected] INTRODUCTION
Total hip arthroplasty has a rich history of innovation and some have rightly called it the “Operation of the century”. The earliest total hip replacement goes back to 1891 where Professor Themistocles Gluck presented the use of ivory to replace femoral head for post tubercular arthritis. Along the way there were attempts by Smith-Peterson with his “mold arthroplasty” using glass in 1925 and then went onto Stainless steel as a material of choice in his later generation prosthesis. Meanwhile, the true revolution in joint replacement is attributed to Sir John Charnley, who worked at the Manchester Royal Infirmary and developed the
principle of “Low Friction Arthroplasty” in the early 1960’s and thus heralded the revolution in joint replacement surgery.
Surgical Approaches to Total Hip Arthroplasty (THA)
There are many surgical approaches which have been described for performing THA. The approach is primarily determined by surgical training, perceived advantage and disadvantage of each approach and surgeon familiarity with each approach. Broadly, surgical approaches in THA can be divided as posterior, lateral and anterior approaches. In posterior approach the abductor mechanism of the hip is not violated and posterior capsule is divided and arthroplasty performed. The primary criticism of this approach is the higher incidence of dislocation in comparison to other approaches. Lateral or antero-lateral approach in some way or other violates the abductor mechanism and thus has the disadvantage of potentially disturbing the main motor of the hip joint and could lead to long term issues if there is no healing of the abductor mechanism. Direct anterior approach is a true inter-nervous approach with minimal disruption to the hip musculature and thus leading to a better early recovery than other approaches. Having said that a well performed THA by any approach will generally result in a good clinical outcome; the idea should be to tailor the approach to a given clinical situation.
Posterior Approach
This is the most commonly used approach for performing THA. The advantages of this approach is, it is the most commonly used and taught approach. The basic premise of this approach is that the Gluteus Maximus is split and the hip joint approached just posterior to the Gluteus medius tendon (Fig. 1). The other advantage is that there is no disruption of in the abductor mechanism of the hip joint while the disadvantage is a higher dislocation rate in comparison to the lateral, anterolateral or the anterior approach.
The lateral approach to total hip arthroplasty has numerous modifications which go by eponymous names as described by its authors. But, it suffices to mention that all these approaches in some form or another involve damage to the abductor mechanism of the hip joint. The most widely used approach is the Hardinge approach, where the Gluteus medius and the Vastus lateralis are taken in a single lazy J incision and an anterior dislocation of the hip performed. This approach can be performed either with the patient supine or in the lateral position. The disadvantage of this approach is that if dissection extends 5 cm proximal to the tip of the trochanter it could end up damaging the Superior gluteal nerve and leading to a limp clinically.
Fig. (1)) The approach is just posterior to the gluteus medius tendon.
Direct anterior approach to THA has off late taken the fancy of arthroplasty surgeons. This approach has been described long time ago, where the patient is positioned supine and approached by an inter-nervous plane involving the femoral and Superior gluteal nerve. The plane is developed between the TFL and the Sartorius superficially and Gluteus medius and Rectus femoris in the deeper plane (Fig. 2). The advantage of this approach is early mobilization, earlier restoration of gait kinematics and lesser dislocation rates. The disadvantages of this approach is the difficulty to access femoral canal, which needs special equipment like offset broaches, reamers and some surgeons use a specialized table for this approach.
Fig. (2)) Direct anterior approach showing the method of positioning the retractors.
Surgical Approaches During Revision Total Hip Replacement
Revision total hip replacement poses certain unique challenges where the existing components have to be removed with minimal loss of bone and also give adequate access to perform extensive reconstruction. Most surgeons use a variation of the posterior approach to perform their revision surgery. It can be combined with trochanteric slide, conventional trochanteric osteotomy or an extended trochanteric osteotomy with little additional damage to the abductor mechanism. Trochanteric Slide is a procedure where the Gluteus Medius, Vastus Lateralis are taken together as a sleeve along with a 1cm thick bone fragment from the greater trochanter and after the surgery reattached to the existing bony bed with bone to bone healing. Conventional trochanteric Osteotomy consists of reflecting the entire abductor mechanism of the hip proximally and the most important advantage is that it does not damage the Superior gluteal nerve. The problems with this approach is that adequate thickness of bone has to be taken for bone to bone healing and if the flap is too thick it might compromise the lateral support for the femoral stem. There is a higher chance of non-union and “trochanteric escape” proximally. It needs to be reattached with Cables or Trochanteric claw plate. Schutzer SF et al. reported a 97% union rate with a 3 or 4 wire reattachment technique [1]. To avoid the problems of reattachment a...