Hip Replacement Approaches

By Dr. Alan Puddy | September 2022

Hip arthritis remains one of the most common conditions resulting in disability and

results in significant physical, mental, and emotional struggles for many patients. If non-

operative treatments do not result in satisfactory improvement, patients may pursue hip

replacement as a surgical treatment option. Hip replacement has a history dating back over a

century and has undergone many changes since the first procedures were completed. As the

implant options have evolved slowly over time, so have the surgical procedures. One aspect of

the procedure that many patients have questions and concerns over is the surgical approach

that will be utilized. The surgical approach includes not only the location of the incision, but

also the soft tissue dissection required to access the hip joint and complete the surgery. Many

approaches have been described in the orthopedic literature and remain in use today, which

leads patients to wonder if any one approach would be better than others for their specific

condition. In this article, the most common approaches will be described to provide a

background for discussing this further with your orthopedic surgeon.

Posterior Approach

Surgical exposure of the hip joint requires visualization of both the socket side of the

joint (acetabulum) and the top of the femur (femoral head and proximal femur). The most

common surgical exposure of the hip joint during replacement is the posterior approach. 1 The

procedure involves an incision on the outside of the hip and may curve downwards towards the

buttocks as well. After the incision is made, access to the hip joint requires several tendons,

referred to as the short external rotators, to be released from the back of the femur. Beneath

these muscles lies the joint capsule, which must also be taken down. The posterior approach

provides excellent exposure of both the acetabulum and femur. The incision can also be easily

lengthened down the femur, which may be needed in certain complex joint replacements or

situations were fractures are present. The dissection does not involve the hip abductors, which

are important in stabilizing the pelvis while walking.

While the posterior approach has significant advantages, there are also limitations

related to the procedure. As mentioned above, the short external rotators and joint capsule

must be incised to allow adequate access to the hip joint. Many hip replacements were

performed in the past without repair of these structures as the procedure was concluded.

Orthopedic literature has clearly shown that an adequate repair is required to result in joint

stability after replacement. As a result, this approach has historically been associated with the

highest rate of hip dislocation after replacement. While that rate has been dramatically

reduced by surgeons performing better repair of these structures at the conclusion of the

surgery, most surgeons limit activities and certain positions of the hip while healing occurs over

the first six weeks.

Anterior Approach

Although many patients believe that the anterior approach to the hip is a relatively

recent development in hip replacement, the surgical dissection was initially described for hip

replacements in 1949 by Marius Smith-Petersen. 2 Several modifications have been made since

the initial surgeries and this approach is typically now referred to as the direct anterior

approach to the hip. The surgery involves an incision on the front of the upper thigh that

typically starts just below the corner of the pelvis called the anterior superior iliac spine that

can be felt through your skin. The thigh skin crease just below that bony prominence is

approximately where the incision would start and extend down the front part of the thigh. This

is a muscle sparing approach, which may decrease post-op pain and recovery time. Another

advantage of this approach to the joint is that the posterior anatomy is not disrupted,

minimizing the risk of posterior hip dislocations. Additionally, this procedure is performed with

the patient lying on their back and provides the surgeon with the most predictable position of

the hip throughout the surgery. Because of this position, surgeons may more easily use intra-

operative imaging to guide the procedure and the placement of implants.

The disadvantages of the direct anterior approach are mostly related to access to the

top part of the femur, which is more difficult to access and requires the surgeon to perform a

sufficient number of cases, known as the learning curve, before achieving competence. Also, a

nerve supplying the skin on the upper lateral thigh can be compressed by instruments during

the surgery or injured by the surgeon resulting in thigh numbness or pain in this area. For

patients with a belly, there may also be a higher risk of wound breakdown.

Lateral Approach

The lateral approaches to the hip have become less popular over the last several

decades, but are still utilized today. These approaches are more of a family of described

procedures including the direct lateral approach and anterolateral approaches. The skin

incision is on the outside of the thigh similar to the posterior approach, but the muscle

dissection differs in that it is carried out over the front side of the femur. This family of

approaches require one or more tendons on the front or side of the hip to be removed from

their attachment points. These are repaired at the end of the surgery, but can result in a limp

while walking until these heal. Formation of new bone around the area of the surgery, called

heterotopic ossification, is also more common with lateral approaches. On the contrary, the

lateral approaches are associated with the lowest risk of dislocation after surgery in several

studies compared to posterior and anterior approaches. 3 The incision can also easily be

extended down the leg in the same way as for the posterior approach, if needed. Thus, this

remains a versatile approach.

Other Approaches

The posterior, anterior, and lateral approaches to the hip are certainly the most

commonly performed, but some orthopedic surgeons use other surgical approaches to the hip

in an effort to leverage the advantages of some while limiting the disadvantages. Many other

approaches have been described, such as the superior or Northern approach, the anterior

based muscle sparing approach, two incision approaches, and others. ii Unfortunately, the

amount of clinical data on many of these alternative approaches is lacking since they are less

frequently used. As a result, there may be more uncertainty regarding the likelihood of a

satisfactory outcome and the rates of potential complications when one of these approaches

are employed.

Clinical Results

Total hip replacement is the most successful operation performed in orthopedics and

has a great track record regarding return of function and low complication rates. The

orthopedic literature has made significant efforts to quantify patient outcomes as well as

potential complications with regard to the different surgical approaches that are available. The

majority of that literature, however, focuses on comparisons of anterior and posterior

approaches since they are most common. While there will likely never be complete agreement

on conclusions from every study that has been performed, some trends in those studies are

clear and will be discussed here further.

Functional Outcomes

Perhaps the most important aspect of hip replacement from a surgeon’s perspective is

the return of function that is obtained following surgery. Surgeons strive to perform a

procedure that will return the patient to near normal function as quickly as possible.

Comparisons of anterior and posterior approaches in hip replacement have demonstrated an

advantage of the anterior approach in early return of function. In a study performed in 2018,

patients who underwent hip replacement through the anterior approach had less pain while in

the hospital, required less pain medication during that time, and were able to walk further in

their early physical therapy sessions. The trend towards better function regarding walking

distance held true in this study until eight weeks after surgery. Time points beyond eight weeks

demonstrated similar function in all patients. 4 Other studies have also demonstrated similar

trends with anterior approaches generally showing better functional return until the four-to-

eight-week post-op point. 5 Longer term outcomes from both approaches are similar, however,

and satisfactory in the vast majority of patients.

Complications

Perhaps the more feared aspect of hip replacement surgery is the possibility of

complications that affect results or require additional surgery. The complication rate is low,

around 2% of all initial hip replacements, but can result in significant patient morbidity. Since

the rate is so low, large patient databases have been required for comparison of complication

rates between the various hip approaches. One of the largest studies so far was performed in

Australia and looked at 122,345 hip replacements performed with an anterior, lateral, or

posterior approach. The most significant complications after an anterior approach were femur

fractures and loosening of the implant in the femur. 6 Most surgeons believe these

complications are higher with the anterior approach due to the slightly increased difficulty in

exposing the femur during the operation as compared to other approaches. Although fractures

can certainly still occur with the lateral and posterior approaches, they were less common. The

lateral and posterior approaches, however, demonstrated a higher number of deep infections

requiring additional surgery and a larger percentage of hip dislocations. Other studies have also

looked at complications rates with another significant trend being an increased rate of surgical

incision complications with the anterior approach, which is believed to be due to the proximity

of the incision to the thigh skin fold.

Conclusions

Hip replacement remains a very successful surgical procedure for many patients

regardless of the surgical approach to the hip. While some surgeons perform the same

approach to the hip in almost all of their patients, others regularly perform multiple approaches

and develop specific criteria for selecting one approach over the others for a particular patient.

Many patient factors may play a role in this decision, such as a patient’s weight, body type,

pelvis shape and contour, previous surgery, prior trauma, complexity of the surgery required,

and others. Patients may play a significant role in the decision as well, as it is relatively

common for patients to discuss hip replacement with friends or family and come to the office

with a specific approach in mind. As a result, if the selected approach is important to the

patient, then this should be one component of a thorough pre-operative discussion prior to

surgery.

1 Moretti, VM, Post, ZD Surgical Approaches for Total Hip Arthroplasty. Indian J Orthop 2017;51:368-76.

2 Aggarwal, VK, et al. Surgical Approaches for Primary Total Hip Arthroplasty from Charnley to Now: The Quest

for the Best Approach. JBJS Reviews 2020;8(1):e0058.

3 Pincus, D., et al. Association between surgical approach and major surgical complications in patients undergoing

total hip arthroplasty. J Am Med Assoc 2020;323(11):1070-1076.

4 Taunton, M., et al. Randomized Clinical Trial of Direct Anterior and Miniposterior Approach THA: Which

Provides Better Functional Recovery? Clin Orthop Relat Res 2018;476:216-229.

5 Parvizi, J., et al. Total arthroplasty performed through direct anterior approach provides superior early outcome:

Results of a randomized, prospective study. Orthop Clin North Am 2016;47(3):497-504.

6 Hoskins, W., et al. Early Rate of Revision of Total Hip Arthroplasty Related to Surgical Approach: An Analysis of

122,345 Primary Total Hip Arthroplasties. JBJS 2020;102-A(21):1874-1882.

7 Aggarwal, VK, et al. Surgical approach significantly affects the complication rates associate with total hip

arthroplasty. Bone Joint J 2019;101-B:646-651.