I perform more than 700 hip and knee replacements a year, and after twenty years no question comes up more often in my Franklin office than this one: what actually happens once I am asleep? This article walks through the operation step by step; for the full overview of direct anterior approach hip replacement in my practice, including candidacy, robotics, and recovery, start there.
What is direct anterior approach hip replacement?
Direct anterior approach hip replacement is a total hip replacement performed through the front of the hip, using the natural seam between two muscles instead of cutting through them.
Those muscles are the tensor fascia lata (a flat muscle on the outer front of the thigh) and the sartorius (the long strap muscle that crosses the thigh). They are neighbors with a gap between them. I work in the gap.
The approach is not new: Carl Heuter described it in 1881, and Smith-Petersen published his version in 1917. Modern tables, retractors, and imaging made it practical for routine use.
How is the operating room set up before the first incision?
Setup starts with you lying flat on your back, and that one detail drives everything else. Face up, I can see both legs at once, so leg length and implant position get measured against your other hip in real time instead of estimated by feel.
Why the specialized table matters
Many anterior surgeons use a HANA table, a positioning table built for hip and knee arthroplasty. Your leg sits in a padded boot, and the table extends, rotates, and lowers it on command during the femoral part of the case.
A standard operating table works too. The specialized table simply gives more controlled access to the femur.
How long does direct anterior approach hip replacement take?
Skin to skin, most of my anterior hip replacements take 60 to 90 minutes. Plan on most of a morning in the building, even when you go home that day.
Where is the incision made for direct anterior approach hip replacement?
The incision runs 3 to 4 inches along the front of the hip, starting about an inch below and outside the bony point at the front of your pelvis and angling toward the outer thigh.
That bony point is the anterior superior iliac spine, or ASIS. The second landmark is the greater trochanter, the bump on the outside of your upper thigh bone.
Traditional approaches often use an 8 to 12 inch incision. A shorter one is not automatically a better operation; it reflects a shorter path, not a rushed one.
How does the surgeon reach the hip joint without cutting muscle?
The surgeon opens the fascia over the tensor fascia lata, then separates it from the sartorius with a finger, opening a corridor straight down to the front of the hip capsule.
No major muscle is divided. No tendon is detached and repaired. That is the entire argument for this approach.
What happens layer by layer
- Skin and fat. A soft tissue protector at the wound edge limits crushing from retractors.
- Fascia. The tough sheet over the tensor fascia lata is opened along its fibers, not across them.
- Muscle interval. Blunt finger dissection develops the plane between the two muscles. Fingers, not blades, do most of this work.
- Blood vessels. A branch of the lateral circumflex femoral artery and its veins cross the field at a predictable spot and are sealed before they bleed.
- Capsule. Retractors go above and below the femoral neck, and the capsule (the sleeve around the joint) is opened and tagged for later repair.
One nerve deserves a sentence. The lateral femoral cutaneous nerve supplies feeling to the skin on the front of the thigh and runs near this corridor. It is protected deliberately, but stretch can leave a patch of numbness there for a few months. That is skin sensation only, not strength.
How are the worn joint surfaces removed and the implants placed?
The femoral head is cut free at the neck and lifted out, the socket is reamed and a cup pressed in, and a stem is fitted into the thigh bone, with a trial run checked before any final implant goes in.
Cutting and removing the femoral head
The cut across the femoral neck follows a plan measured from your X-rays. A corkscrew driven into the head gives me a handle to twist and deliver it, and live X-ray confirms the cut landed where the plan said.
Preparing the socket
Retractors move the femur aside and bring the arthritic socket into view. Rim spurs and the labrum remnant come out first. Reamers shape the socket in stages until it matches the cup, which is pressed into that prepared bone.
Robotics matters most here. I use the Mako® robotic-arm system from Stryker®, and I am a paid Stryker consultant on that platform, so let me be plain: the robot does not perform your operation. It holds the plan built from your imaging and keeps cup angle and depth inside a narrow range while I work.
Preparing the femur and checking leg length
The leg is then rotated outward, extended, and brought across so the top of the thigh bone lifts into the wound. Broaches shape the inside of the femur to accept the stem.
A trial ball and stem go in and the hip is put back together. I check three things before committing: stability through a full range of motion, leg length, and offset (how far the leg sits out from the pelvis).
Lying flat is what makes that check honest. Under fluoroscopy (live X-ray) both hips appear on one screen, and I use OrthoGrid Hip AI® overlay software to measure the difference. Anything off by a few millimeters is corrected right there. Then the final implants go in.
How is the incision closed, and how soon do patients get up?
Closure runs the approach in reverse: the capsule is repaired, the fascia is sewn shut, the fat layer is closed with dissolving stitches, and the skin is sealed with a buried stitch, glue, and a waterproof dressing. A drain is optional; I rarely use one.
Most of my patients stand and take steps with a therapist the same day, and most go home that evening or the next morning. Full weight bearing is allowed immediately; the walker is for balance, not because the hip cannot carry you.
Because nothing at the back of the hip was cut, the classic list of forbidden positions mostly disappears. I give one rule instead: stay out of the extremes of motion for the first several weeks. More detail is in my article on anterior hip replacement precautions.
What are the advantages and trade-offs of direct anterior approach hip replacement?
The advantage is a faster first six weeks. The trade-offs are a real surgeon learning curve, longer operative times in less experienced hands, and a risk of temporary thigh numbness.
A randomized Mayo Clinic trial of 101 patients compared anterior surgery with a mini posterior approach. Anterior patients stopped using a walker at 10 days versus 14.5, gave up all walking aids at 17.3 days versus 23.6, came off narcotics at 9.1 days versus 14, and climbed stairs with an aid at 5.4 days versus 10.3. Dislocation rates are also consistently lower in large anterior series, which is the clinical reason the precaution list goes away.
Now the other side, which you will not read on most surgery pages. Complication rates fall sharply after a surgeon’s first 40 to 100 anterior cases, so experience matters more than the technique itself. Wound problems and thigh numbness are reported slightly more often. And by six to twelve months, well done hip replacements through either approach land in roughly the same place, a point the American Academy of Orthopaedic Surgeons makes in its patient materials.
Here is what I tell my patients: the anterior approach mostly buys you a gentler first month, and that month is exactly what most people worry about. For the week by week version, see the hip replacement recovery timeline.
Who is a candidate for direct anterior approach hip replacement?
Most people with severe hip arthritis are candidates. I use direct anterior approach hip replacement for the large majority of my hip patients. Certain anatomy still makes it harder or unwise:
- A socket that has migrated deep into the pelvis (acetabular protrusio), limiting access to the femur
- A flatter neck shaft angle that seats the femoral canal deeper in the thigh
- Retained hardware or bone loss at the back of the socket, where anterior exposure is poor
- Revisions and complex deformity that need wider exposure
When your anatomy points that direction, the posterior approach is a good operation and I use it without hesitation. The goal is a hip that works for decades, not loyalty to one incision.
Where can Middle Tennessee patients have this procedure done?
I perform direct anterior approach hip replacement at the Bone and Joint Institute of Tennessee, 3000 Edward Curd Lane, Franklin, TN 37067, just off I-65. Patients travel in from Nashville, Brentwood, Columbia, Spring Hill, Murfreesboro, and across Middle Tennessee.
You can read about my training on my about page, or see how robotic joint replacement fits in. The American Association of Hip and Knee Surgeons also publishes patient resources on hip arthroplasty.
Ready to talk it through? Schedule a consultation with Dr. Calendine or call (615) 791-2630. No referral required.
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Disclaimer: This article is educational only and is not a substitute for a medical evaluation. Individual results vary. Always consult a qualified orthopedic surgeon about your care. In a medical emergency, call 911.
References
- Taunton MJ, Trousdale RT, Sierra RJ, Kaufman K, Pagnano MW. John Charnley Award: randomized clinical trial of direct anterior and miniposterior approach THA: which provides better functional recovery? Clin Orthop Relat Res. 2018;476(2):216-229. PubMed
- 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. PubMed
- Post ZD, Orozco F, Diaz-Ledezma C, Hozack WJ, Ong A. Direct anterior approach for total hip arthroplasty: indications, technique, and results. J Am Acad Orthop Surg. 2014;22(9):595-603. PubMed
- Sheth D, Cafri G, Inacio MCS, Paxton EW, Namba RS. Anterior and anterolateral approaches for THA are associated with lower dislocation risk without higher revision risk. Clin Orthop Relat Res. 2015;473(11):3401-3408. PubMed
- Galakatos GR. Direct anterior total hip arthroplasty. Mo Med. 2018;115(6):537-541. PubMed
- Rachbauer F, Kain MSH, Leunig M. The history of the anterior approach to the hip. Orthop Clin North Am. 2009;40(3):311-320. PubMed
