What Is an Artificial Hip?

The human hip joint is a spherical joint that contains a spherical femoral head and a bowl-like acetabulum. It is a joint formed by the femur (femur) and the pelvis. The spherical surface and the inner surface of the bowl are covered by smooth cartilage. Mucus is secreted by the bursa membrane to minimize friction. When there is a lesion in the hip joint, the cartilage is no longer smooth, the synovial sac is inflamed and atrophied, and the joint can no longer function as normal. When the hip joint becomes painful, stiff or deformed due to degeneration, disease or trauma, or even has difficulty moving, it is impossible to relieve the symptoms with drugs or other treatment methods. Usually, the artificial hip joint is replaced by surgery for the patient to resume daily activities. ability.

Chinese name: Artificial hip joint
Shape: spherical

Constitute: Femoral head and a bowl-like acetabulum
Types of: body parts

Artificial hip joint principle

The artificial hip joint prosthesis is modeled after the structure of the human hip joint. The stem of the prosthesis is inserted into the femoral bone marrow cavity, and the head is used to rotate with the acetabulum or the metal cup of the prosthesis to achieve flexion and extension of the femur. Prosthetic stems are made of titanium alloy, cobalt-chromium-molybdenum alloy, ultra-low carbon stainless steel materials, acetabulum is made of non-toxic ultra-high molecular polyethylene, and metal ball heads are made of titanium alloy (with titanium alloy, cobalt-chromium-molybdenum alloy femoral head handle (Matching) and ultra-low carbon stainless steel materials.

Artificial hip joint life

The life of hip joints made of different metal materials are: a. Titanium alloy: 10-15 years of service life; b. Cobalt chromium molybdenum alloy: 10-15 years of service life; c. Ultra-low carbon stainless steel materials: service life is 4 to 6 years.

Artificial hip joint structure

1. Mortar cup: usually made of titanium alloy or cobalt chromium molybdenum alloy and implanted into the acetabulum of the pelvic cavity.

2. Pad: It includes polyethylene, ceramics, metal, etc. as the interface of the joint.

3. Ball head: It is connected to the femoral stem and used as a joint interface to move. Generally made of ceramic or metal materials.

History of artificial hip joint development

Artificial hip replacement includes artificial femoral replacement and total hip replacement. In 1958 Peterson invented the cup-shaped artificial joint made of cobalt-chromium-molybdenum alloy. In the early 1950s, Mc Kee in the United States developed a metal (head) -metal (acetabular) combination joint prosthesis made of cobalt-chromium-molybdenum, which failed because of too much wear debris on the metal-to-metal prosthesis. To this end, Charnley of the United States designed a metal-plastic artificial hip joint combination based on his theory of hip joint low friction. Charnley's first hip joint consisted of a femoral head made of stainless steel and an acetabulum made of Teflon, but the wear rate of Teflon was too high. In 1962, a new artificial hip joint composed of a metal femoral head with a diameter of 22.5 mm and a high-molecular polyethylene acetabulum was developed. During surgical replacement, it was fixed with bone cement (polymethyl methacrylate), which is called low friction artificial joint replacement. Its success has greatly promoted the clinical application of artificial hip joints. It can be said that the modern artificial hip joint work began with the contribution of Charnley. Artificial hip joint surgery has a history of more than 30 years. For patients with femoral head necrosis, elderly femoral neck fractures, comminuted acetabular fractures, and femoral head tumors, this is the only treatment that can maintain joint function. After many years of clinical application and improvement, the hip replacement effect is very good. Generally, the excellent rate of 10 years can reach about 90%, and the excellent rate of 15-20 years still exceeds 85%.

During World War II, British veteran Jeffries performed an artificial hip replacement for a hip fracture. The artificial hip has worked for 60 years and set a world record.

Application of artificial hip joint

Human hip replacement surgery is suitable for the following cases: hip pain that is ineffective in conservative treatment; hip osteoarthritis or arthritis diagnosed by X-rays; inability to work, sleep or move due to hip pain; joint failure after hip repair Stable; part of hip fracture; hip joint tumor.

Artificial hip replacement

Artificial hip arthroplasty is divided into artificial hip arthroplasty, which is the most widely used clinically, and hip surface replacement technology, that is, handleless artificial hip arthroplasty.

Artificial total hip arthroplasty is an artificial hip joint including an acetabular cup, a pad, a ball head, and a femoral stem, which is implanted in the human body to replace the diseased human hip joint, thereby improving the quality of life of patients and has a wide range of clinical applications.

The shank artificial hip joint must be fixed in the femoral bone marrow cavity of the human body with its shank. The contact between the artificial joint and the human femur is strong, and complications such as loosening, wear and infection of the artificial joint are prone to occur after surgery. Sinking causes the patient's long and short legs, which seriously affects the service life of the artificial joint. Therefore, the shank artificial hip joint is only suitable for patients over 45 years old. Surface replacement is a recommended surgical procedure for young osteoarthritis patients. Because the technology is not very mature, there are not many clinical applications.