Direct Anterior Approach · Total Hip Arthroplasty · Adelaide SA

Anterior Hip
Replacement.
Explained in full.

From the first signs of hip arthritis through to walking on the day of surgery. A complete guide to the direct anterior approach by Dr Chien-Wen Liew, FRACS, Orthopaedic Surgeon, Adelaide.

Direct Anterior (DAA)
Muscle Preserving
Eastwood Private, Adelaide
Dr Chien-Wen Liew FRACS
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>95%
10-year implant survivorship
AOANJRR 2023
Zero
Muscles detached
Internervous plane
Day 0
Walking after surgery
Same-day mobilisation
>95%
10-year implant survivorship for total hip replacement in Australia
AOANJRR Annual Report 2023
57k
Total hip replacements performed in Australia each year
AOANJRR Annual Report 2023
0
Major muscles detached from bone during the direct anterior approach
Internervous, intermuscular plane
Day 1
Physiotherapy commences, typically with same-day walking after surgery
Standard post-op protocol
01
Chapter 01 / Understanding the Problem

Hip Arthritis:
what it is, how it progresses.

The hip is a ball-and-socket joint. The ball (the femoral head) sits within a deep cup called the acetabulum. Both surfaces are lined with articular cartilage: a smooth, resilient tissue that allows near-frictionless movement through a full arc of motion.

Osteoarthritis develops when this cartilage breaks down progressively. The process cannot be reversed once established. As cartilage thins, the space between ball and socket narrows. Subchondral bone becomes exposed, bone-on-bone contact develops, osteophytes form, and the joint progressively deforms.

Typical symptoms include deep groin pain (frequently mistaken for a muscle strain), along with morning stiffness, difficulty putting on shoes and socks, a shortened stride, and eventually pain at rest and overnight. Sleep disruption is common in moderate-to-severe disease.

Risk factors include increasing age, family history, previous hip injury, and altered hip anatomy such as dysplasia or femoroacetabular impingement. Arthritis is not an inevitable consequence of physical activity in the absence of these factors.

"When conservative measures no longer control symptoms that are disrupting daily life and sleep, surgery becomes a serious and appropriate option."

Dr Chien-Wen Liew, FRACS
Arthritis Progression, Kellgren-Lawrence Grading GRADE 1 Normal Intact cartilage Normal joint space GRADE 2 Mild Mild narrowing Early osteophytes GRADE 3 Moderate Marked narrowing Significant osteophytes GRADE 4 Severe Bone on bone Surgical threshold
Kellgren-Lawrence radiographic grading of hip osteoarthritis. Grade 4 typically indicates surgical candidacy.

When is surgery indicated? Surgical discussion is appropriate when symptoms are no longer adequately controlled by physiotherapy, anti-inflammatory medication, or intra-articular injection; when pain significantly disrupts sleep, work, or mobility; and when imaging confirms Grade 3 or 4 arthritis consistent with symptoms. There is no mandatory threshold.

02
Chapter 02 / The Surgical Approach

The Direct Anterior Approach:
why muscle preservation matters.

Total hip replacement can be performed through several surgical approaches. The fundamental difference between them is which soft tissues are divided to gain access to the joint. The direct anterior approach (DAA) is unique in that it works through a natural anatomical corridor, specifically the interval between the tensor fasciae latae and the sartorius muscles, without cutting or detaching any major muscle from bone.

This is in contrast to the posterior approach, which requires detachment of the short external rotator muscles, and the lateral approach, which splits or reflects the gluteus medius. Both approaches require subsequent reattachment and a period of protected healing before full strength returns.

"The anterior approach follows a plane nature already created. No muscles are lifted from the bone. The hip is accessed between structures rather than through them."

Dr Chien-Wen Liew, FRACS
Watch: What is a Total Hip Replacement?

Approach Comparison

Feature Direct Anterior (DAA) Posterior Approach
Muscles detachedNone (internervous plane)Short external rotators detached and repaired
Patient positionSupine (on back)Lateral decubitus (on side)
Intraoperative X-rayYes: live confirmation of cup, stem, leg lengthGenerally not used
Dislocation riskLower with correct component orientationHigher if posterior capsule repair fails
Hip precautions post-opTypically not requiredOften required for 6 weeks
Early mobilisationSame day, full weight-bearingSame day, but often more guarded
Learning curveSignificant; requires specific trainingMore widely practised
Anterior Approach: Internervous Plane DAA corridor Tensor fasciae latae Sartorius interval Preserved: Gluteus medius Gluteus minimus Short ext. rotators Iliopsoas tendon
The DAA uses the natural interval between TFL and sartorius. All major hip muscles are preserved intact.

The clinical benefit of muscle preservation

The practical consequence of not detaching any muscle is that patients can bear full weight immediately after surgery. There is no waiting for a repair to heal because nothing has been divided that requires healing.

Nakata et al. (2009) demonstrated significantly shorter hospital stays and superior early gait scores in DAA patients compared with those receiving the posterolateral approach. Taunton et al. (2014) reported equivalent or superior patient-reported outcomes at mid-term follow-up.

01
Same-day mobilisation
Walking with the physiotherapist on the day of surgery is standard protocol.
02
Reduced dislocation risk
The anterior soft tissue envelope provides inherent stability without posterior capsule repair.
03
No hip precautions
Patients are generally free to move without the crossing-leg restrictions of the posterior approach.
04
Faster functional return
Return to light activities and driving is typically achieved at 2 to 3 weeks.
References: Nakata et al. J Arthroplasty 2009; Taunton et al. Bone Joint J 2014; Matta et al. Clin Orthop 2005.
03
Chapter 03 / Precision Before the First Incision

3D Patient-Specific Planning:
nothing is left to guesswork.

Every patient's hip anatomy is different. The acetabular orientation, femoral offset, leg length discrepancy, and bone stock all vary between individuals. Attempting to manage this variation intraoperatively, without a detailed pre-operative plan, introduces unnecessary risk and opportunity for imprecision.

Pre-operative CT scanning generates a three-dimensional model of the patient's specific anatomy. Using proprietary planning software, implant size, cup inclination and anteversion, stem sizing, and leg-length restoration are all determined before the first incision is made. The plan becomes the surgical target.

The advantage is that decisions made in a calm, unhurried planning environment (with measurement tools, templating overlays, and the ability to run multiple scenarios) are superior to decisions made under time pressure in the operating theatre.

Watch: 3D Planning and Patient-Specific Technology
MyHip 3D pre-operative planning software — Dr Chien-Wen Liew Adelaide MyHip 3D planning software — patient-specific CT anatomy with virtual implant templating

Leg length discrepancy after hip replacement is a common source of patient dissatisfaction. Pre-operative 3D planning, combined with intraoperative fluoroscopic confirmation, substantially reduces this risk.

04
Chapter 04 / Implant Selection

Implant Design:
materials that outlast decades of activity.

The acetabular component is a hemispherical titanium alloy shell, press-fit into the prepared acetabulum and supplemented with screws where indicated. The inner bearing surface is a ceramic liner — specifically a Zirconia-Alumina composite (CeramTec) chosen for its exceptional hardness and among the lowest wear rates of any bearing surface currently available.

The femoral component is a tapered titanium alloy stem, press-fit into the prepared femoral canal and integrated with bone through biological osseointegration over the ensuing weeks. The femoral head (the ball) is ceramic, paired with the ceramic liner to create a ceramic-on-ceramic articulation. This combination produces near-zero wear particle generation and is the preferred bearing for active patients and those with longer life expectancy.

Implant selection is patient-specific. Factors including bone quality, anatomy, activity level, and age inform the choice of fixation method, bearing surface, and sizing. Implants used are those listed on the Australian Register of Therapeutic Goods and have long-term AOANJRR survivorship data.

"I use implants with the strongest long-term data from the Australian Joint Registry: not the newest, not the most marketed."

Dr Chien-Wen Liew, FRACS
3D render of total hip replacement implant — MyHip planning by Dr Chien-Wen Liew Adelaide
3D patient-specific implant model — MyHip planning software

Implant specifications

Cup fixation
Press-fit cementless, screws as required
Cup material
Titanium alloy shell
Liner bearing surface
Ceramic (CeramTec Zirconia-Alumina)
Femoral head
Ceramic
Articulation
Ceramic-on-ceramic
Stem fixation
Cementless press-fit
Stem material
Titanium alloy
Registry
AOANJRR-listed with long-term data
Osseointegration
Biological ingrowth, 6 to 12 weeks
Watch: Hip Implant Materials Explained
05
Chapter 05 / Intraoperative Confirmation

Intraoperative X-ray:
seeing exactly what has been achieved, before closing.

One of the underappreciated advantages of the supine (on your back) position used in the anterior approach is direct access to fluoroscopy (live X-ray imaging) throughout the procedure. The patient is positioned on a standard operating table or a specialised traction table, and a C-arm image intensifier can be brought in at any point.

In practice, fluoroscopy is used to confirm cup position (inclination and anteversion), stem seating, femoral head reduction, and leg-length restoration before the final components are locked in place and the wound is closed. If any measurement falls outside the planned target, it can be corrected at that moment.

This real-time feedback loop is the critical link between the pre-operative 3D plan and the final surgical result. No amount of planning compensates for a component placed off-target; intraoperative X-ray provides the opportunity to verify before the opportunity to correct has passed.

Vigdorchik et al. (2019) demonstrated that cup malpositioning is a primary risk factor for hip dislocation. Intraoperative fluoroscopic verification is one of the most effective tools available to the surgeon to prevent this complication.

Implant positioning simulated on CT scan and 3D kinematic simulation — MyHip planning software Implant positioning simulated on the original CT (top left and right) alongside 3D kinematic simulation confirming range of motion pre-operatively.

"I take an X-ray before closing on every case. The plan is what we aimed for; the X-ray confirms whether we achieved it."

Dr Chien-Wen Liew, FRACS
06
Chapter 06 / Long-Term Survivorship

The national data:
how long does a hip replacement last?

The Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) is one of the most comprehensive joint replacement databases in the world. It tracks every hip replacement implanted in Australia, recording revision rates, complications, and outcomes across all registered implants and hospitals.

Registry data for 2023 demonstrate greater than 95% survivorship at 10 years for modern total hip replacement in Australia. The 15-year and 20-year data show a gradual attrition, with survival rates of approximately 90% and 80% respectively, though these figures depend significantly on the specific implant used, patient age, and activity level.

Revision is required when a component loosens, when the bearing surface wears to a symptomatic degree, or in the event of infection or dislocation. Modern cementless fixation and highly cross-linked polyethylene liners have substantially reduced revision rates over the past two decades.

Watch: What to Expect from Your Hip Replacement
Kaplan-Meier Survivorship Curve, THR Australia 100% 97% 95% 90% 85% 10yr: >95% 0 2 5 15 20 Years post-surgery Survivorship (%)
Schematic based on AOANJRR 2023 data. Individual outcomes depend on implant selection, patient factors, and surgical technique.
95%+
At 10 years
AOANJRR 2023 national data for all-cause revision
90%
At 15 years
Gradual attrition with modern cementless fixation
Key Principle
The approach matters. So does the surgeon's experience with it.
The direct anterior approach carries a meaningful learning curve. Outcomes in experienced hands differ from those in early-adoption hands. When choosing a surgeon, ask specifically about their volume and experience with the anterior approach.
DAA
Direct Anterior Approach: the most muscle-preserving technique available
0
Muscles detached from bone during the entire procedure
3D
Pre-operative planning using patient-specific CT-derived anatomical models
Xray
Live intraoperative fluoroscopic confirmation before wound closure
07
Chapter 07 / Recovery and Rehabilitation

What to expect:
week by week after surgery.

Recovery after anterior hip replacement follows a broadly predictable pattern, though the pace varies between individuals. Factors including overall fitness, pre-operative function, and the severity of deformity all influence the rate of progress.

The most important principle is that recovery is active, not passive. The muscles around the hip (which were not divided) are functional from the outset. Physiotherapy commences on the day of surgery and continues as an active programme for the following 6 to 12 weeks.

Expectations vs reality: Most patients experience a rapid early improvement in pain, often within the first week. Functional recovery (strength, endurance, return to sport) takes longer: typically 3 to 6 months for a full return to activity. Pain that improves substantially but then plateaus at 3 to 4 months is expected, not a sign of failure.

Post-operative physiotherapy and rehabilitation after hip replacement
Physiotherapy commences on the day of surgery and continues as an active programme
0
Day of Surgery
Surgery and first steps
Surgery under spinal or general anaesthetic. Physiotherapy-assisted walking commences within hours of surgery. Discharge planning begins.
1
Days 1 to 3
Hospital stay and discharge
Progressive mobilisation with physiotherapy twice daily. Pain managed with multimodal analgesia. Discharge home or to a rehabilitation facility within 1 to 3 days for most patients.
2
Weeks 1 to 2
Home recovery, wound care
Walking with crutches or a frame. Wound care and swelling management. Outpatient physiotherapy begins. Stairs are possible with assistance from the first day.
3
Weeks 2 to 6
Independence and early return
Transition off crutches. Return to driving typically at 2 to 3 weeks — earlier than posterior approach due to no muscle cutting and no hip precautions. Short walks without aids. Clinic review at 6 weeks with X-ray.
4
3 to 6 Months
Functional strength and return to activity
Strength training progresses. Return to golf, swimming, cycling, hiking, and light sport. Osseointegration of the implant is fully established by 6 months.
5
12 Months and Beyond
Full recovery, ongoing monitoring
Most patients are at or near full function at 12 months. No further routine reviews or X-rays are required unless symptoms develop. Higher-impact activities should be discussed at the 12-month appointment.
About the Author
Dr Chien-Wen Liew, Orthopaedic Surgeon Adelaide
Dr Chien-Wen Liew
MBBS · FRACS (Orthopaedic Surgery) · Adelaide, South Australia
Dr Chien-Wen Liew is an orthopaedic surgeon in Adelaide, South Australia, who exclusively performs 2 operations only — total hip replacements and total knee replacements. He performs all hip replacements via the direct anterior approach with patient-specific 3D planning and intraoperative fluoroscopic confirmation. All knee replacements are performed using kinematic alignment and patient-specific technology, restoring each patient's individual anatomy rather than a standardised mechanical position. He is a Fellow of the Royal Australasian College of Surgeons and practises at Eastwood Private Hospital.
FRACS (Orthopaedics)
AOA Member
Direct Anterior Approach
Patient-Specific 3D Planning
Eastwood Private Hospital
Orthopaedics 360 Adelaide
View full profile at drchienwenliew.com.au
08
Chapter 08 / Frequently Asked Questions

Common questions answered.

Am I a candidate for anterior hip replacement?
+
Candidates are those with symptomatic hip osteoarthritis or avascular necrosis unresponsive to non-surgical management, who are medically fit for anaesthesia and surgery. There is no strict age cut-off; fitness and bone quality matter more than age alone. A formal consultation with history, examination, and imaging review is required to determine suitability.
What are the advantages of the direct anterior approach?
+
The direct anterior approach uses an internervous plane that avoids cutting or detaching any major muscle. This translates to faster early functional recovery, same-day mobilisation, and reduced dislocation risk compared with traditional posterior approaches. The supine position also allows intraoperative fluoroscopic X-ray verification, which improves implant positioning accuracy.
How long does an anterior hip replacement last?
+
AOANJRR data show greater than 95% survivorship at 10 years for modern hip implants. Long-term performance depends on implant design, patient factors such as activity level and BMI, and surgical technique. Modern cementless fixation and highly cross-linked polyethylene liners have significantly improved long-term durability compared with implants from two decades ago.
When can I walk after surgery?
+
Most patients walk with the physiotherapist on the same day as surgery. Full weight-bearing is permitted from day one. Transition off crutches typically occurs within 2 to 6 weeks depending on individual progress, strength, and confidence.
What is 3D patient-specific planning?
+
Pre-operative CT scanning generates a 3D model of the patient's specific anatomy. Implant size, positioning, and restoration of leg length are determined before the first incision is made, reducing intraoperative surprises. The plan serves as a precise surgical target and is verified intraoperatively using fluoroscopy.
Are there hip precautions after anterior hip replacement?
+
Because no muscles are detached, there are generally no obligatory hip precautions such as avoiding crossing the legs. This differs from the posterior approach, where precautions are typically enforced for 6 weeks. Specific instructions will be discussed prior to and after surgery based on the individual case.
When can I return to driving?
+
Most patients return to driving at 2 to 3 weeks post-operatively. Because the direct anterior approach involves no muscle cutting and no hip precautions, the main requirements are that you are off opioid pain medication and can perform an emergency stop safely and confidently.
How do I arrange a consultation with Dr Liew?
+
Consultations require a referral from your general practitioner or other specialist. The referral can be sent to Orthopaedics 360 in Adelaide. Details and contact information are available at drchienwenliew.com.au.
Scientific References
  1. Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Annual Report 2023. Adelaide: AOA; 2023.
  2. Matta JM, Shahrdar C, Ferguson T. Single-incision anterior approach for total hip arthroplasty on an orthopaedic table. Clin Orthop Relat Res. 2005;441:115-124.
  3. Taunton MJ, et al. Direct anterior versus miniposterior THA with the same advanced bearing and antifibrinolytic agent. Bone Joint J. 2014;96-B(7):907-13.
  4. Nakata K, et al. A clinically and radiographically prospective comparison of the direct anterior and miniposterior approaches in THA. J Arthroplasty. 2009;24(5):698-704.
  5. Vigdorchik JM, et al. Hip-spine syndrome: Defining the interaction between the lumbar spine and the hip in relation to total hip arthroplasty outcomes. Orthopedics. 2019;42(6):299-306.
  6. Christensen CP, et al. The Mark Coventry award: hip mechanics after total hip arthroplasty. Clin Orthop Relat Res. 2015;473(2):442-450.
  7. Lovell TP. Single-incision direct anterior approach for total hip arthroplasty using a standard operating table. J Arthroplasty. 2008;23(6 Suppl 1):64-68.

Ready to take the next step?Book a consultation with Dr Chien-Wen Liew

A formal assessment including history, examination, and imaging review is required to determine surgical suitability. Your GP can provide a referral to Orthopaedics 360 in Adelaide.

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This page is intended as general patient education only and does not constitute medical advice. All surgical procedures carry risks. Individual outcomes depend on factors specific to each patient. A formal consultation with a qualified medical practitioner is required before any treatment decision. Dr Chien-Wen Liew is a Fellow of the Royal Australasian College of Surgeons (Orthopaedic Surgery) and practises in accordance with AHPRA guidelines.