Hip arthroplasty is the surgical replacement of a damaged hip joint with artificial components. The term covers several procedures, from replacing just the ball of the joint to replacing both the ball and socket entirely. It’s one of the most common orthopedic surgeries performed worldwide, primarily done to relieve severe hip pain and restore mobility when other treatments have stopped working.
Types of Hip Arthroplasty
The hip is a ball-and-socket joint. The ball is the rounded top of your thighbone (femur), and the socket is a cup-shaped hollow in your pelvis called the acetabulum. Hip arthroplasty replaces one or both of these surfaces with manufactured parts.
Total hip arthroplasty (THA) replaces both the socket and the ball. A metal stem is inserted into the hollow center of the thighbone, topped with a new ball made of metal or ceramic. A new socket lining, typically made of plastic or ceramic, is fitted into the pelvis. This is the most common form of hip replacement.
Hemiarthroplasty replaces only the ball side of the joint, leaving the natural socket intact. This is most often used for elderly patients who fracture their hip, particularly breaks at the neck of the thighbone. Because it’s a smaller operation, it carries a lower surgical burden for patients who may not tolerate a longer procedure.
Hip resurfacing is a less common option where the damaged bone surface is trimmed and capped with a metal shell rather than removed. It preserves more of the natural bone and is sometimes used in younger, active patients, though it plays a relatively minor role compared to total replacement.
Why It’s Done
The overwhelming reason for hip arthroplasty is osteoarthritis that has progressed to the point where it significantly limits daily life. In a survey of 147 orthopedic surgeons, virtually all of them (99%) ranked pain and loss of movement as the most important factors when recommending surgery. Reduced walking distance and overall quality-of-life burden were close behind at 97%.
Surgery isn’t typically the first option. Current guidelines call for a confirmed diagnosis, documented impact on quality of life, and evidence that nonsurgical treatments like pain medication and physical therapy have been tried for at least three months without adequate relief. Other conditions that can lead to hip arthroplasty include rheumatoid arthritis, avascular necrosis (where bone tissue dies from poor blood supply), and hip fractures.
What the Implant Is Made Of
A hip implant has three main parts: the stem that fits inside the thighbone, the ball that sits on top of it, and the socket liner pressed into the pelvis. Stems are almost always metal, usually titanium alloys or specialized high-strength steel. The ball component is made from either polished metal or ceramic. The socket liner is where material choices vary the most.
Four bearing combinations are used in practice: metal on plastic, metal on metal, ceramic on ceramic, and ceramic on plastic. Metal-on-metal designs have fallen out of favor due to concerns about metal debris. Ceramic-on-ceramic pairings produce the least wear but can, in rare cases, produce a squeaking sound. The most common modern pairing uses a ceramic ball against a highly cross-linked polyethylene (a dense, wear-resistant plastic) liner, which balances durability with low friction.
How Long Implants Last
A large pooled analysis of over 215,000 hip replacements published in The Lancet found that about 89% of implants were still functioning at 15 years, 70% at 20 years, and 58% at 25 years. These numbers represent averages across all implant types and patient populations. Younger, heavier, or more active patients tend to wear through implants faster, while improvements in materials and surgical technique have pushed newer implants toward the higher end of these ranges.
If an implant does eventually wear out or loosen, a revision surgery can replace the worn components. Revision procedures are more complex than the original surgery, and complication rates climb with each successive revision. Dislocation rates, for example, jump from about 6% after a first revision to over 27% after a fourth or greater revision.
Surgical Approaches
Surgeons reach the hip joint through one of three main routes: from the back (posterior), from the side (direct lateral), or from the front (direct anterior). Each involves a different path through muscle and tissue to access the joint.
The posterior and direct lateral approaches both require cutting through muscle tissue. The posterior approach splits through the large gluteal muscle and the small rotator muscles at the back of the hip. The lateral approach goes through the gluteal muscles on the side. The direct anterior approach is the only common technique that works between muscles rather than through them, making it what surgeons call “muscle sparing.” That said, it still causes some damage to surrounding tissues, with studies showing injury to the muscle at the front of the hip in roughly 31% of its surface area.
No single approach is universally superior. The choice often depends on the surgeon’s training and experience, your anatomy, and your specific condition.
Robotic-Assisted Surgery
Robotic-arm systems allow surgeons to plan implant placement using 3D imaging before the operation, then use the robotic arm for guidance during the actual procedure. A meta-analysis comparing robotic-assisted to manual hip replacement found that the robotic approach placed the socket component in the target zone significantly more often and produced better functional scores in the short to mid-term. However, the same analysis found no difference in complication rates or implant survival between the two methods. Robotic assistance improves precision, but both approaches produce good outcomes.
Recovery Timeline
Most people are up and walking with assistance within a day of surgery. Modern incisions are small and closed with dissolvable stitches, though the incision site takes about six weeks to fully heal. If the surgery was on your left hip, you may be able to drive again in one to two weeks (right hip takes longer because of the brake pedal).
Physical therapy starts almost immediately and continues for several weeks. The six-week mark is a significant milestone: it’s when most surgeons clear patients to return to physically demanding jobs and when incisions are considered healed. By 12 weeks, pain levels from the surgery itself typically drop to minimal levels, around a 1 or 2 out of 10.
Activity After Recovery
Low-impact activities get a green light from nearly all surgeons. Walking, swimming, hiking, cycling on flat terrain, golf, and stationary biking are broadly encouraged. Many patients actually increase their participation in these activities after surgery compared to before, simply because their hip pain is gone.
High-impact and contact sports are a different story. Basketball, soccer, boxing, gymnastics, handball, hockey, squash, and skiing are generally advised against or recommended only with significant caution. Studies show a measurable drop in participation in activities like jogging, volleyball, and alpine skiing after hip replacement. This isn’t necessarily because patients can’t do them, but because the repetitive pounding or sudden twisting accelerates implant wear and raises the risk of dislocation. Tennis falls in a gray area, with some surgeons permitting doubles play but discouraging competitive singles.