participate in rehabilitation and achieve the desired clinical goals for functional independence. Additionally the learner will be able to describe the role of PT both in the preoperative and postoperative phases for the patient undergoing THA and be able to describe an optimal rehabilitation program for these time periods based on current research. Clinical cases presented will facilitate the learner being able to select appropriate rehabilitative strategies following THA.
This intermediate-level course is relevant for clinicians who are new to the field of orthopedics as well as more seasoned counterparts. With many changes in this frequently performed surgical procedure, such as the surgical approaches used in THA, variations in different materials for the prostheses, and updates in the fixation methods used, it is important that the clinician be aware of these updates when working with patients who have undergone THA. Additionally, clinicians should be aware of the growing body of research supporting the role of PT both pre- and postoperatively with this growing population.
EPIDEMIOLOGY
The first total hip arthroplasty (THA) is thought to have been performed in the 1930s in the United Kingdom, but it was not until the 1960s and the development of the low-friction arthroplasty by Sir John Charnley that this procedure really gained popularity (Mellon, Liddle, & Pandit, 2013). According to the American Academy of Orthopaedic Surgeons (AAOS), there are currently more than 300,000 THA surgeries (also known as total hip replacement or THR) performed each year in the United States (American Academy of Orthopaedic Surgeons [AAOS], 2015). It is estimated that by the year 2020 the number of primary THA surgeries performed annually will exceed 384,000 and will jump to more than 572,000 by 2030 (Kurtz, Ong, Lau, Mowat, & Halpern, 2007). The number of hip revision surgeries, which are necessary to replace worn, loosened, or migrating prosthetic parts, also continues to rise. In 2005 40,800 revision THAs were performed with the projection that by 2030 there will be a need for on average of 96,700 revision procedures to be performed annually. This represents a predicted 116% increase in this surgical procedure (Kurtz et al., 2007). Although results vary according to the age and activity level of the patient and the type of implant used, THA provides improved quality of life, pain relief, and increased function compared to presurgical levels (Agostini et al., 2014; Anakwe, Jenkins, & Moran, 2011). The authors of a study looking at revision rates found that the risk of revision was approximately 2% per year for the first 18 months after the failure of a primary THA and then 1% per year for the remainder of their follow-up period of 12 years (Katz et al., 2012).
The primary purpose of a THA is for pain relief with secondary purposes of restoring joint function, increasing range of motion, and weight-bearing ability in the presence of conditions that affect the hip joint, such as OA, rheumatoid arthritis, avascular necrosis, congenital hip dysplasia, fractures, tumors, and infections. The mean age of patients undergoing THA is 65 years, but now, many patients younger than age 65 are increasingly electing to have their hips replaced or resurfaced to reduce pain and enable them to lead full, active lives (Jorgensen, Kehlet, Lundbeck Foundation Centre for Fast-track, Hip & Knee Replacement Collaborative, 2013). The decision to undergo a THA is normally only considered after conservative care such as PT or pharmacological management has failed and joint pain has become chronic and unrelenting, and consistently interferes with a person’s quality of life. Although evidence-based research is slow to accumulate, it is thought that THA surgery is most successful when patients are preoperatively educated and committed to the rehabilitation process, effectively supported by the multidisciplinary medical team throughout the perioperative period, and given individualized postoperative rehabilitation to help patients fully regain range of motion, strength, functional mobility, and ambulatory status that facilitates an independent and active lifestyle (K Enseki & Berliner, 2013; Monaghan et al., 2016; Slaven, 2012; Snow et al., 2014; Stambough, Nunley, Curry, Steger-May, & Clohisy, 2015).
RELATED ANATOMY
Understanding the anatomy of the hip joint including the osseous, ligamentous, and muscular structures will enhance a clinician’s appreciation for the various surgical approaches now used in THA and the impact of these variations. In addition to The skeletal system The hip joint is composed of the convex femoral head (the ball) and the concave acetabulum (the socket) where the acetabulum is the junction of the three bones of the pelvis: the ilium, the ischium, and the pubis (Chang & Huang, 2013). Both the femoral head and the acetabulum are covered in articular cartilage. The articular cartilage of the femoral head covers the entire surface, whereas the cartilage that lines the acetabulum covers a portion of the acetabulum and is horseshoe-shaped. The depth of the acetabulum is increased by the presence of a fibrocartilaginous structure, the acetabular labrum. The acetabular labrum surrounds 270° of the acetabular rim circumference. The femoral head attaches to the femur via the femoral neck (Figure 1). The femoral neck connects to the femoral shaft at an angle, (known as the angle of inclination), which is on average 125° (Neumann, 2016). The femoral neck allows the femur to swing clear of the pelvis with each stride.
an anatomical review of the joint and surrounding structures, the next section will review the impact of biomechanical alignment as it pertains to THA.
Figure 1: The Right Anterior Femoral Head and Neck
Note. Adapted from Gray, H. (1918). Figure 244. Gray’s Anatomy of the Human Body (20th ed.). Philadelphia, PA: Lea & Ferbinger. Retrieved from http://www.bartleby.com/107/59.html#244
EliteLearning.com/Physical-Therapy
Book Code: PTNY3622B
Page 139
Powered by FlippingBook