Anterior, Lateral and Posterior Approach: How They Differ

The anterior, lateral and posterior approaches to hip replacement differ in which side the surgeon comes from and which tissues they pass through to reach the joint. In Georgia the lateral, or direct lateral, approach is the most widely used; worldwide the posterior approach is the most common; and the anterior approach has been adopted increasingly widely over recent decades. All three methods are recognised, and in the hands of an experienced surgeon all three give good long-term results.

What an approach means in hip replacement

The approach is the anatomical route by which the surgeon reaches the joint from the skin. The substance of the operation does not change with the approach: in every case the damaged femoral head is replaced with an implant and a cup is placed in the acetabulum.

The difference lies in which muscles, tendons and part of the capsule lie on the way. That is what determines the restrictions in the early period and what has to heal after the operation.

One clarification is often needed. The approach and the implant are two separate decisions. The same prosthesis can be placed through all three approaches, and conversely: different types of implant are used through the same approach. When a patient asks about an operation, it helps to keep the two questions apart.

How each approach is carried out

All three approaches have the same aim: reaching the joint safely, removing the damaged head and placing the implant correctly. What differs is only which tissues lie on that route and what has to be repaired at the end.

The lateral, or direct lateral, approach

In the lateral approach the incision is made on the outer surface of the thigh and the route to the joint passes through part of the gluteus medius and of the vastus lateralis. This muscular portion is repaired and sutured at the end of the operation.

The lateral approach is the one most often used in Georgia. Its wide adoption is no accident:

• Good stability. The posterior structures are left untouched, which reduces the risk of dislocation.
• Technical reliability. The approach is well described, the landmarks are clear and the view is sufficient.
• Few positional restrictions. Unlike the posterior approach, a strict ban on deep sitting and crossing the legs is usually not imposed.
• Wide experience. Most surgeons are trained in this technique, which means availability for the patient.

The main consideration with the lateral approach is also well known: the route passes through part of the gluteus medius, and it is precisely this muscle that levels the pelvis during walking. After the operation, until it has healed and regained strength, it can show in the gait of some patients as a temporary limp. In most cases this improves with rehabilitation.

The anterior approach

In the anterior approach the incision is made on the front of the thigh and the joint is reached through a natural interval between two muscles. In anatomy this gap is called an interval and it exists naturally: the surgeon uses it rather than creating it.

The practical consequence is that the main muscle groups are not cut but moved aside. The gluteal muscles that provide stability during walking do not lie on the route. That is exactly what distinguishes it from the lateral approach.

The operation is usually performed with the patient lying on their back. This allows the surgeon to use X-ray guidance during the operation and to compare the length of both legs. Equal leg length is one of the most important practical matters for a patient, because a difference shows up in the gait and in the lower back.

One variant of the anterior approach is the bikini incision, where the skin cut runs obliquely along the natural crease: the bikini incision and its direction. The full description of the method, with the protocol and the risks, is on the anterior approach page.

The posterior approach

In the posterior approach the incision is made on the outer and back surface of the buttock, and the route to the joint passes through the posterior muscle group and the posterior capsule of the joint. These structures are repaired at the end of the operation.

The posterior approach is the most widely used and the best studied method in the world. Its strengths are a wide view, the ability to extend the incision easily, and many years of practice behind it, which is particularly valuable in complex and repeat, revision operations.

The consideration with the posterior approach is positional restrictions. Until the repaired posterior structures have healed, deep sitting, crossing the legs and internal rotation of the leg are temporarily restricted. The surgeon sets the timescale and the restrictions are temporary.

How the three differ from each other

The three approaches differ in where the surgeon comes from, which tissues lie on the route, and what restrictions the patient has in the early period.

Feature	Anterior	Lateral	Posterior
Route to the joint	Between muscles, through a natural interval	Through part of the gluteus medius	Through the posterior muscle group
Site of the incision	Front of the thigh	Side of the thigh	Outer and back of the buttock
Position during surgery	On the back	On the side or the back	On the side
Risk of dislocation	Low	Low	Relatively higher, hence the restrictions
Restrictions on positions	Usually none	Usually none	Temporarily imposed
Effect on gait in the early period	The muscle is not cut	Possible temporary limp	Usually none
View and extensibility	More limited	Good	The widest
Use in Georgia	Less common, growing	The most widespread	Moderate

The table is a guide, and each column carries a different weight for a particular patient. Someone who spends more time on their feet and is focused on an early return will pay more attention to one line; someone with complex anatomy to a different one.

A couple of words on the history are worth adding. The lateral approach has been in use for decades and became the standard in the post-Soviet region. The anterior approach is not a new invention either: its description is old too, but it began to spread widely once specialised instruments, operating tables and the practice of intraoperative X-ray guidance had developed.

Which one is better

There is no universally better approach. The honest answer is this: in the long run, meaning years later, the results of all three methods converge, and the difference shows mainly in the early period.

The expected advantages of the anterior approach concern the early period: the muscle is not cut, positional restrictions are usually not imposed and, often, the return to normal activity is faster. The time to return is individual: it depends on the patient’s starting condition, age, muscle strength and the surgeon’s experience. That timescale cannot be established from the name of the approach alone.

The strength of the lateral approach is stability and technical reliability, and of the posterior a wide view and flexibility in difficult cases. Each has its own typical weak point: the posterior approach the risk of dislocation, the lateral temporary weakness of the gluteal muscle, and the anterior irritation of a sensory skin nerve. These figures depend more on the surgeon’s experience than on the method itself.

The anterior approach has one characteristic, though usually harmless, feature: a sensory skin nerve runs near the incision, and irritating it causes numbness or a burning sensation on the outer surface of the thigh. This does not affect muscle strength or walking and usually fades over time.

What role the surgeon’s experience plays

The surgeon’s experience plays a considerably greater role than the choice of approach. Correct implant position, restored leg length and joint stability are the three factors that determine the result, and they depend on the surgeon and not on the approach.

The anterior approach has a learning curve of its own. In the literature it is around one hundred cases, with the sharpest improvement over the first thirty operations. That is exactly why I believe the main question for a patient is not “which approach is better” but “which approach does this surgeon know well”.

In consultation I advise patients to ask the surgeon directly about several things: which approach they work with day to day, how implant size and position are planned before the operation, how leg length is checked during it, and what happens if the plan changes. A comprehensible answer to those questions says more than the name of a method.

My practice is focused on the anterior approach, and it is the study of this method that I devoted my fellowships to. That does not mean another approach is bad: it means my hand is trained on this one. More about me is on the about page.

Who the anterior approach suits less

The anterior approach is not the optimal choice in every case. That has to be said honestly, because presenting one method as universal helps a patient less than accurate information does.

Choosing the approach calls for separate assessment where there is:

• significantly altered anatomy, for instance after an old injury or previous surgery;
• a repeat, revision procedure, where a wide view and the ability to extend are critical;
• a body build that makes the anterior approach technically harder;
• marked deformity or fusion of the joint that significantly restricts movement.

The decision is made during preoperative planning, on the basis of the images and the examination. The logic of choosing the timing of surgery is set out in detail here: when the time for an operation arrives.

It also matters that the plan can change during the operation. If the anatomy differs from what was expected, the surgeon chooses the safe option. The priority is correct placement of the implant and stability of the joint. I explain this to patients in advance so that it does not come as a surprise.

What to remember

• The approach is the route to the joint and does not change the substance of the operation.
• The lateral, or direct lateral, approach is the most widely used in Georgia.
• The lateral gives good stability, at the cost of partly dividing the gluteal muscle.
• In the anterior approach the main muscles are not cut but moved aside.
• The surgeon’s experience matters more than the choice of approach.

Choosing an approach starts from the anatomy, not from the name of a method. Bring your images and we will assess together which option suits your case better: book a consultation.