- Approach
- Between muscle planes, no muscle detached
- Position
- Supine, allowing on-table radiograph
- Hospital stay
- 1 to 3 nights
- Hip precautions
- Usually not required
- Scar
- Front of the thigh, roughly 8 to 12cm
- Implant
- Same components as any approach
Professor Rodda explains how an anterior hip replacement is performed, and why the approach matters.
What the operation involves
The hip is a ball-and-socket joint. The ball is the head of the femur, at the top of the thigh bone, and the socket is the acetabulum, a cup-shaped hollow in the pelvis. Both surfaces are lined with articular cartilage, a smooth layer a few millimetres thick that allows the joint to move with very little friction.
In a total hip replacement, both of those surfaces are replaced. The damaged femoral head is removed and a metal stem is fitted into the hollow centre of the thigh bone, with a new ball attached at the top. The worn cartilage in the socket is cleared and a metal cup is fitted into the pelvis, holding a smooth liner. The new ball then articulates against that liner.
The word "total" distinguishes this from a partial hip replacement, or hemiarthroplasty, in which only the femoral head is replaced and the natural socket is left in place. Partial replacement is used mainly in the treatment of certain hip fractures rather than for arthritis.
What the implant is made of
| 01 | The stem. | Sits inside the femur. Usually titanium. Most stems used in younger and middle-aged patients are uncemented, with a textured or coated surface that bone grows into over the first several weeks. Cemented stems, fixed with bone cement, are still used in some circumstances, particularly in older patients or where bone quality is reduced. |
|---|---|---|
| 02 | The head. | The new ball. Usually ceramic, sometimes metal. Ceramic is very hard and highly polished, which produces low wear against the liner. |
| 03 | The cup. | Fits into the pelvic socket. Titanium, and in most cases uncemented, held initially by a press fit and then by bone growth into the outer surface. |
| 04 | The liner. | Sits inside the cup and forms the bearing surface. This is made of ceramic or highly cross-linked polyethylene. |
The combination of head and liner material is called the bearing surface. Professor Rodda most commonly uses a ceramic-on-ceramic bearing surface. Although this is the most expensive bearing surface for the insurance companies, it is also the one that biomechanical studies have shown to have the best wear characteristics. The Australian National Joint Replacement Registry has demonstrated that ceramic on highly cross-linked polyethylene also has extremely good wear characteristics and potentially the lowest revision rates historically.
How the operation is performed
The hip joint can be accessed to perform hip replacement surgery by multiple routes. These are referred to as the surgical approach. The two most commonly used in Australia are the direct anterior approach and the posterior approach. Professor Rodda uses the anterior approach for 100% of his primary hip replacements. He has used this approach relatively exclusively for the last decade. He is very passionate about this approach and trains other surgeons from around Australia, as well as international surgeons, in the nuances of this approach.
The anterior approach has several potential benefits, but the downside is that it is technically demanding. When surgeons are new to the approach, the evidence suggests a higher rate of complications, particularly femoral fractures. This is known as the learning curve. One question a patient should always ask their surgeon when considering an anterior approach is: how many of these procedures have they performed, and their rationale for using the approach?
Anaesthesia and the day of surgery
Hip replacement is usually performed under spinal anaesthetic with sedation, or under general anaesthetic. With a spinal, the lower half of the body is numbed and sedation is given so that the patient is asleep or drowsy throughout. The anaesthetist assesses each patient before surgery and decides on the approach with them.
The operation itself typically takes around an hour, though this varies with anatomy and complexity. Including preparation, anaesthesia and recovery, the total time from ward to ward is usually several hours.
Local anaesthetic is infiltrated around the joint during the procedure as part of a multimodal pain management plan, which combines several types of pain relief so that reliance on any one medication is reduced.
What recovery looks like
Most people are helped to stand and take a few steps on the day of surgery or the following morning, with a physiotherapist and a walking aid. Weight-bearing is generally permitted immediately. Hospital stay is commonly one to three days, and some people are suitable for discharge on the day after surgery.
A walking frame or crutches are used initially, usually progressing to a single stick over the first two to three weeks, and then to no aid as confidence and strength return. Wound review takes place at around two weeks, and formal physiotherapy generally starts after that.
By around six weeks, many people have resumed most usual activities, including driving. This timeframe is a general guide rather than a schedule; age, fitness before surgery, other medical conditions and the state of the hip at the time of surgery all affect the pace of recovery, and individual experience varies considerably.
Recovery
What to expect, week by week
These are typical timeframes. Recovery varies between individuals.
| Day of surgery | Once the anaesthetic wears off you can usually put full weight through the hip, with a frame or crutches and a physiotherapist alongside you. Standing on the same day helps. | gold |
|---|---|---|
| Day 1 | Walking with a frame or crutches. Some people go home on day one if they are safe and comfortable. | |
| Days 2 to 5 | Discharge home once you are comfortable, walking independently and managing stairs. This is judged individually rather than set in advance. | |
| Weeks 2 to 3 | Wound review, usually with a wound nurse. Dissolving sutures and glue mean removal is rarely needed. Physiotherapy begins after this review. | |
| Weeks 2 to 6 | Down to a single stick in the opposite hand for longer walks, and often nothing at all around the house. The stick is phased out as balance returns. | |
| From 6 weeks | Most people have resumed their usual activities, including driving. Some return to driving earlier after a left hip replacement in an automatic car. |
The week-by-week recovery timeline is covered in detail in the Hip library
Risks
All surgery carries risk. The risks specific to total hip replacement are uncommon but they are real, and they should be understood before consenting to an operation. They include:
- Infection, either superficial or involving the joint itself
- Dislocation of the new joint
- Difference in leg length
- Fracture of the femur or pelvis during or after surgery
- Blood clot in the leg or lung
- Injury to nerves or blood vessels around the hip
- Loosening or wear of the components over time
- Ongoing pain despite a technically satisfactory replacement
- Risks associated with anaesthesia
Individual risk depends on age, weight, smoking status, diabetes, previous surgery and other medical conditions. Some of these factors can be modified before surgery, and doing so is part of preparation. Your surgeon and anaesthetist will discuss the risks that apply to you specifically before you consent to the procedure.
How long a hip replacement lasts
The Australian Orthopaedic Association National Joint Replacement Registry records essentially every joint replacement performed in Australia and reports on how long implants remain in place. Registry data published in the AOANJRR 2024 annual report shows that the large majority of total hip replacements are still functioning at twenty years, with twenty-year cumulative revision rates ranging from around five to sixteen per cent depending on the prosthesis combination used.
Longevity is influenced by age at the time of surgery, activity level, body weight, bearing material and implant design. Younger and more active patients place greater demand on a replacement over their lifetime and have a correspondingly higher chance of requiring revision surgery at some point. An individual estimate is best discussed at consultation.
Questions worth asking at your consultation
- Based on my X-ray and examination, is a hip replacement the right option for me now?
- What have I not yet tried that might delay the need for surgery?
- Which approach would you use in my case, and why that one?
- What implant and bearing would you use, and what is the reasoning?
- What does recovery look like for someone my age and fitness?
- Which of the risks apply particularly to me?
- What will the total cost be, including hospital, anaesthetist and any excess?
Frequently asked questions.
How painful is a hip replacement?
Pain after hip replacement is managed with a combination of medications, local anaesthetic given during surgery and early mobilisation. Most people describe the pain as significant for the first few days and then steadily improving. The majority find that the arthritic pain they had before surgery is gone immediately, and that what remains is surgical soreness, which settles over several weeks.
How long will I be in hospital?
Most people stay between one and three days after a total hip replacement. Discharge depends on being comfortable on oral pain relief, being able to walk safely with an aid and being able to manage stairs if there are stairs at home. Some patients are suitable for discharge the day after surgery, and this is assessed individually rather than set in advance.
When can I drive again?
Most people return to driving between two and six weeks after hip replacement, once they can control the vehicle safely, perform an emergency stop and are no longer taking medication that affects alertness. Return is often earlier after a left hip replacement in an automatic car. Check with your insurer, as policies differ on cover after surgery.
Will I set off airport security scanners?
Modern hip replacements sometimes trigger airport metal detectors, though many do not. No implant card or documentation is required in Australia, and security staff are familiar with joint replacements. If a scanner is triggered, telling the officer you have a hip replacement is sufficient.
Can I kneel, cross my legs or bend down after a hip replacement?
After a direct anterior approach hip replacement there are generally no movement restrictions, and bending, crossing the legs and reaching the floor are permitted straight away as comfort allows. After a posterior approach, bending the hip beyond ninety degrees and crossing the legs are usually avoided for around six weeks to reduce the risk of dislocation.
What is the difference between a total and a partial hip replacement?
A total hip replacement replaces both the ball and the socket. A partial hip replacement, or hemiarthroplasty, replaces only the ball and leaves the natural socket in place. Partial replacement is used mainly for certain fractures of the hip in older patients, rather than for arthritis, where the socket is also affected.
Will one leg be longer than the other afterwards?
Restoring equal leg length is a goal of the operation and is planned before surgery and checked during it. Small differences of a few millimetres are common and are usually not noticeable. Occasionally a larger difference results, which can be managed with a shoe raise. A limb that felt shorter before surgery due to arthritis may feel different once the hip is corrected.
Is the anterior approach better than the posterior approach?
It is associated in published trials with a faster first six weeks, less early pain and earlier independence from walking aids. Beyond about three months the published outcomes converge, and long term implant survival is not different. So it is reasonable to say the early recovery differs and the destination does not. The best approach is the one that suits your anatomy and is performed by a surgeon experienced in it.
Is it minimally invasive?
The term is used loosely and is best avoided. The incision is broadly similar in length to other approaches. What differs is that the muscle is separated rather than cut or detached, which is a difference in tissue handling rather than in the size of the wound.
Will I have hip precautions?
Usually not. The structures at the back of the hip that resist dislocation are not disturbed, so the restrictions on bending, crossing legs and sleeping position that follow a posterior approach are generally not required. You will be given instructions specific to your operation.
What is the numb patch on my thigh?
The lateral femoral cutaneous nerve supplies sensation to the outer thigh and runs close to the interval used in this approach. Irritation of it can cause a patch of numbness, tingling or altered sensation. It is reported in a proportion of cases, is usually not painful, does not affect strength or walking, and commonly improves over months.
Can anyone have an anterior approach?
No. Body habitus, femoral shape, previous surgery and retained metalwork can all make another approach safer or more appropriate. The approach is chosen for the individual hip after reviewing your imaging, not applied automatically.
References.
- Australian Orthopaedic Association National Joint Replacement Registry. Annual Report. Adelaide: AOA.
- Miller LE, Gondusky JS, Bhattacharyya S, et al. Does surgical approach affect outcomes in total hip arthroplasty through 90 days of follow-up? A systematic review with meta-analysis. J Arthroplasty. 2018;33(4):1296-1302.
- Higgins BT, Barlow DR, Heagerty NE, Lin TJ. Anterior vs. posterior approach for total hip arthroplasty, a systematic review and meta-analysis. J Arthroplasty. 2015;30(3):419-434.
This page provides general information about a medical condition and a surgical procedure. It is not individual medical advice and does not replace consultation with a qualified practitioner. Outcomes vary between individuals and all surgery carries risk. A referral is needed for a consultation with Professor Daevyd Rodda; without one, you can start with the practice nurse practitioner, who can provide it.