PT Classroom - A Brief Review of Total Hip Replacement  ׀ by Chai Rasavong, MPT, COMT, MBA

According to the Agency for Healthcare Research and Quality (AHRQ) it is estimated that about 11 million Americans will have either a hip or knee replacement by 2030 (1). This will make these joint replacement surgeries one of the nation’s most conventional elective surgical procedures (1). According to the National Center for Health Statistics (NCHS) the number and rate of total hip replacements among inpatients aged 45 and over increased from 2000 to 2010: from 138,700 to 310,800 in number and from a rate of 142.2 to 257.0 per 100,000 population (2). They also found that the percentage of total hip replacements underwent by younger age groups increased while the percentage of total hip replacements for older age groups decreased (2).

Improvement with quality of life and mobility is a key reason why both younger and older individuals opt to undergo a total hip replacement. When undergoing a total hip replacement in these modern times there are two main approaches to consider as far as which procedure a patient will undergo – the posterolateral approach or the anterolateral approach. The surgeon the patient chooses to perform the hip replacement will choose the approach that he or she feels most comfortable with. According to Palan et al. there is no consensus regarding which approach is best for primary total hip arthroplasty (3).

The posterolateral approach involves the surgeon making an incision on the side of the hip just behind the greater trochanter (4). The gluteus maximus muscle is split and does not require repair as the whole tendon is not removed (5). The piriformis and superior gemeli muscles are detached and later reattached to bone and will heal over 4–6 weeks (5). Precautions for the patient to follow after this procedure to avoid hip dislocation includes: avoiding hip flexion greater than 90 degrees, avoiding hip adduction that crosses the midline, avoiding internal rotation beyond a neutral position and avoiding any combination of hip flexion, adduction and internal rotation (6).

The anterolateral approach involves an incision which is made at the front of the hip which begins at the region of the iliac crest and extends down toward the top of the thigh (4). Current advocates claim this approach is entirely muscle sparing, which is not exactly the case (5). Because of the higher risk of damage to the lateral femoral cutaneous nerve in the thigh, the incision may be moved more to the side, forcing an incision through the muscle bellies of the tensor fascia latae and sartorius muscles, rather than in between (5). The piriformis muscle (1 of 4 muscles that allow for external rotation of the hip) is also cut to allow implantation of the new femoral implant. It cannot be reattached from this approach (5). Precautions for the patient to follow after this procedure to avoid hip dislocation includes: avoiding hip extension, avoiding hip external rotation, avoiding a prone position, avoiding bridging and avoiding any combination of hip extension and external rotation (6).

No matter which procedure the patient has undergone, the goal of the physical therapist remains the same in assisting the patient manage pain and regain ROM, strength, mobility & function. It is especially important to take into consideration the specific precuations based on the hip replacement approach the patient underwent when rehabiliating the patient.

Last revised: June 28, 2017
by Chai Rasavong, MPT, COMT, MBA