Hip Replacement Complications: What Can Go Wrong?

Hip replacement is one of the most successful operations in modern medicine. The overwhelming majority of patients get significant pain relief, better mobility, and a dramatic improvement in quality of life. That said, no surgery is completely risk-free, and every patient deserves an honest discussion about what can go wrong, how often it happens, and what we do to minimize it.

As a fellowship-trained joint replacement surgeon who performs more than 600 hip and knee replacements each year, I think you should understand both the risks and the specific steps we take to prevent them.

Infection: the complication I take most seriously

Nationally, infection rates after primary hip replacement are generally reported between 0.5% and 2%. The risk is low, but an infection can be a major problem that occasionally requires additional surgery and prolonged antibiotics. My personal infection rate is approximately 0.1% — and there's no single reason for that. It's multiple layers of prevention working together:

One of the most important factors is operative efficiency. Patients often assume a longer surgery is a more careful surgery — but numerous studies show that longer operative times are associated with higher complication and infection rates. The goal isn't to rush; it's to be efficient. Because joint replacement is my specialty and I do these every week, the operation follows a highly standardized process, and most primary hip replacements take me about 45 minutes to an hour. Less time under anesthesia and less time with the wound open generally means lower risk.

Most of my procedures are performed in an ambulatory surgery center with a dedicated team that does joint replacements every day. That consistency is a big part of why infection rates stay extremely low.

Blood clots

A clot can form in the veins of the leg (a deep vein thrombosis) and, in rare cases, travel to the lungs (a pulmonary embolism). Fortunately, modern prevention has dramatically reduced this risk. Most patients take aspirin for about four weeks after surgery; those with additional risk factors may need a stronger blood thinner.

But the single most important prevention strategy is simple: walking. My patients begin moving almost immediately — often within hours of surgery. Early movement restores circulation and significantly lowers the risk of a clot forming.

Dislocation

A dislocation is when the ball comes out of the socket. Historically this was one of the major concerns after hip replacement — but modern implants and improved technique have dramatically reduced it.

I perform the direct anterior approach, which preserves the posterior soft tissues and muscle envelope that help stabilize the hip, and generally carries a lower dislocation risk than traditional posterior approaches. I also use intraoperative fluoroscopy (real-time X-ray) during surgery to confirm implant positioning, leg length, offset, and overall alignment.

And I evaluate patient-specific factors that can raise dislocation risk, including:

By accounting for these variables before and during surgery, dislocation becomes an uncommon complication.

Leg-length differences

Many patients worry about one leg ending up longer. It's worth knowing that roughly 40% of the general population already has some natural leg-length difference — and arthritis itself can make a leg feel shorter, because cartilage loss and joint collapse change the hip's mechanics. In many cases, part of the goal of surgery is actually restoring the hip to its native anatomy.

To get this right, I use:

Most perceived leg-length differences after surgery improve as the muscles relax and patients regain normal gait mechanics.

Fracture and nerve injury

Fracture. A fracture can occur while seating the implants into the bone, but it's uncommon during a routine primary hip replacement. Patients with osteoporosis, poor bone quality, or complex anatomy carry a somewhat higher risk. Modern implant designs, careful technique, and appropriate implant selection minimize it — and when a fracture does occur, it can usually be recognized immediately and treated during the same operation.

Nerve injury. Permanent nerve injury after hip replacement is very rare. Patients occasionally notice temporary numbness around the incision — especially after an anterior approach, because small skin nerves travel nearby — but these areas usually improve over time and rarely affect function. More significant nerve injuries involving weakness or foot drop are extremely uncommon.

Persistent pain

One of the biggest advantages of hip replacement over knee replacement is that patients generally recover excellent motion and function. The hip is a ball-and-socket joint, so unlike the knee it's uncommon to develop significant stiffness, and most patients improve steadily over the first several months.

Persistent pain is uncommon, but it can occur for a variety of reasons:

The vast majority of patients report substantial, lasting pain relief after surgery.

Implant loosening and long-term wear

Modern hip implants have improved dramatically over the past few decades. Today's are typically titanium and engineered so your own bone grows directly into the implant surface — a biologic fixation that creates an exceptionally durable bond. Long-term studies show excellent survivorship, with more than 90% of modern hip replacements still functioning well at 25 to 30 years. For many patients, the hip replacement they have today may be the only one they ever need — more in how long a hip replacement lasts. In the uncommon event a problem develops, revision surgery can address it.

The role of modern anesthesia

Many patients are surprised that anesthesia affects outcomes too. Most of my patients receive spinal anesthesia rather than general, which has been associated with:

Patients are often walking within hours of surgery and return home the same day.

Putting the risks in perspective

When patients ask me “what can go wrong?” they're really asking an important question: how safe is this operation? The answer is that modern hip replacement is one of the safest and most successful procedures we perform in orthopedics. Complications can occur, and every surgeon should discuss them honestly — but careful patient selection, meticulous technique, modern implants, specialized anesthesia, and standardized recovery have made serious complications increasingly uncommon.