[Dr. Song Sang-ho's Walking Again: A Hip Journey] The Hip Joint at the Center of Our Lives

When the knee hurts, people quickly think of the importance of their joints. When the back hurts, they worry about the spine. But the hip joint often goes unnoticed until something goes wrong. Located deep inside the body, it is not easily visible, and pain from the hip is sometimes felt in the lower back, thigh, or knee instead.

Yet the hip is one of the body's most important weight-bearing joints. It connects the pelvis and the femur, transfers the weight of the upper body to both legs, and serves as the center of nearly every movement — standing, walking, sitting, and rising. Even everyday actions such as climbing stairs, putting on shoes, wearing socks, or getting in and out of a car all depend on the hip joint moving smoothly.

The hip joint is not simply a "hinge" that moves the leg. It must bear weight while also allowing a wide range of motion. Every time we walk, forces far greater than our body weight are repeatedly transmitted through the hip. Even so, a healthy hip moves smoothly without pain, because the round femoral head and the socket that surrounds it form a stable structure, while the cartilage and surrounding muscles absorb shock and control movement.

■ "A Damaged Hip Doesn't Just Make It Hard to Walk"

When a problem develops in the hip, it often begins as discomfort in the groin or buttock area. Walking for long periods becomes painful, and sitting cross-legged or spreading the legs becomes uncomfortable. Putting on shoes or socks grows difficult, and rising from a low chair or getting in and out of a car becomes harder.

As the condition progresses, the pain restricts daily life as a whole. The distance a person can walk shortens, stairs are avoided, and outings decrease. Limping from pain can place added strain on the pelvis, lower back, and the opposite knee, and pain can even disrupt sleep at night.

The problem is greater for older adults. The longer a person cannot walk, the faster muscles weaken and balance deteriorates. Reduced activity can go beyond mere inconvenience and lead to overall physical decline. In the end, hip disease is not simply a problem of a single joint — it becomes a question of whether a person can maintain an independent life.

For that reason, the first question I ask patients in the clinic is not how severe their condition looks on imaging, but the following:

"What can you not do right now?"

In other words, which activities in daily life are being restricted.

Going to the market, taking a walk with a spouse, traveling with grandchildren, going to the bathroom alone — the daily life each person wants back is different. The goal of treatment should not be to make the imaging results look better, but to make this kind of life possible again.

■ “There Comes a Point When Medication and Injections Alone Are Not Enough”

Not every hip condition requires surgery. Depending on the type and stage of the disease, symptoms can be managed with medication, exercise therapy, weight control, and activity modification.

But the situation changes when avascular necrosis of the femoral head has progressed to the point of collapse, when osteoarthritis has severely worn down the cartilage, or when a fracture makes it difficult to restore normal joint function. At that point, a joint that is already structurally damaged cannot be returned to its original state with medication or injections alone.

The standard treatment at this stage is hip joint replacement surgery.

Joint replacement surgery removes the damaged joint surface and replaces it with a new artificial joint. But describing it simply as "surgery that replaces a painful joint with metal and ceramic" does not capture its true meaning.

Its real purpose is to reduce pain and allow the patient to stand, walk, and return to their own life again.

■ "A Good Joint Replacement Surgery Must Restore 'Life,' Not Just a Good 'X-ray'"

A good-looking X-ray after joint replacement surgery does not mean treatment is complete. Leg length must be properly restored, and the joint's center and offset must be restored as closely as possible so that the muscles around the hip can function normally. The joint must be stable, and the patient must be able to move safely at an early stage.

In the end, the goals of hip joint replacement surgery can be thought of in three ways: reducing pain, creating a stable hip joint, and enabling the patient to walk again.

For older patients in particular, how quickly they can get out of bed and move again after surgery matters as much as the success of the surgery itself. For younger, more active patients, the important goal goes beyond simply walking — it is how naturally they can return to work, hobbies, and exercise.

This is why the goals and surgical strategy must differ depending on the patient's age, condition, bone quality, and activity level, even for the same joint replacement surgery.

The hip joint quietly supports our body every day. But once damaged, it can affect not only a person's ability to walk but also their daily life, confidence, and even their independence, and even their independence. Conversely, restoring hip function through appropriate treatment allows a person to walk again, move again, and return to their own life again.

In upcoming columns, I will look at why the hip hurts, why hip fractures are dangerous in older adults, how joint replacement surgery is evolving, why leg length, muscle strength, and stability matter, and what role digital technologies such as robotics and navigation play in actual surgery.

The ultimate goal of hip treatment is not to perform surgery. It is for the patient to walk again.

<Written by Song Sang-ho, Director of Wellton Hospital | Edited by Jang In-sun, Health Kyunghyang reporter>