In today's healthcare, the primary role of a joint prosthesis is to restore joint function and relieve pain. This article provides an in-depth look at the basic aspects of joints: definition, classification, importance, usage scenarios, essential factors to consider while purchasing and customisation options.
1. Definition of joint prosthesis
Joint prosthesis is a medical device that is used to replace damaged or dysfunctional joints in the human body. They are usually made of materials such as metal, polymer polyethylene, ceramics, etc. and are designed according to the form, structure and function of human joints. The purpose of a joint prosthesis is to improve the patient's quality of life by improving joint function, reducing pain and restoring movement.
There are various types of joint prosthesis, mainly including hip, knee, shoulder, elbow, wrist and ankle joints. Of these, total hip and knee replacements are the two most common. Joint replacement surgeries have a high success rate of over 90% and patients usually experience significant improvement in joint function after surgery.
The choice of material for the joint prosthesis has a significant impact on the success of the surgery and the longevity of the prosthesis. Commonly used metallic materials include titanium alloys and cobalt chromium alloys, while non-metallic materials include polyethylene and ceramics. These materials are chosen to improve the biocompatibility, wear resistance and long-term stability of the prosthesis.
As technology advances, joint prosthesis designs and materials continue to be improved, and new prosthetic technologies and treatments are being developed to meet patient needs and improve surgical outcomes. For example, joint prostheses made of ceramic materials are becoming increasingly popular due to their excellent wear resistance and low coefficient of friction.
Overall, joint prostheses are an effective medical treatment for joint diseases and for improving patients' quality of life, and their application has a promising future with the continuous development of material science and surgical technology.
2. Classification of joint prosthesis
According to the different fixation methods, they are divided into two categories: biological fixation type and bone cement fixation type. When choosing, the patient's age, acetabular condition and proximal femoral morphology, bone quality, degree of bone defect, physician's operating habits and other aspects should be considered.
(1) Biologically fixed prosthesis: The initial stability of biologically fixed prosthesis depends on the physical fixation of the prosthesis with the medullary cavity and acetabulum by the shape and surface treatment of the prosthesis, and the long-term stability depends on the biological fixation after the bone grows in or grows on.
Biofixed prostheses can be classified into microporous, sandblasted and hydroxyapatite based on the surface coating. Different types of bioprostheses, if the surgical technique is properly mastered, can achieve good clinical results.
Biofixed prostheses are suitable for the majority of hip replacement patients, especially for those with good bone quality.
Advantages of bioprosthesis include shorter operation time and avoidance of complications that may be caused by the bone cement itself. The disadvantage is that it requires higher surgical technique, especially the size and type of prosthesis should be chosen properly, otherwise it will affect the postoperative effect, in addition, the possibility of intraoperative and postoperative fracture around the prosthesis is slightly higher than that of cemented prosthesis.
(2) Cemented prosthesis: The stability of cemented prosthesis is provided by the formation of micro-interlocking between the cemented bone and the cancellous bone, therefore, this type of prosthesis can provide immediate stability, and the patient can be fully weight-bearing activities after surgery. Cemented prostheses, especially cemented femoral stems, can be used in the majority of hip replacement patients, especially in elderly patients with severe osteoporosis, poor bone condition and comorbidities, where the use of cemented artificial hip joints facilitates early weight-bearing activities.
Advantages of cemented prosthesis include: (1) immediate stability, patients can fully weight-bearing exercise after surgery; (2) the angle of the prosthesis can be adjusted according to the patient's specific situation during the operation.
Disadvantages include: (1) waiting for the cement to cure, so the operation time is longer than the biological prosthesis; (2) the cement curing process may lead to transient changes in blood pressure, heart rate, etc.; (3) once the prosthesis fails, it is difficult to take out the cement when the prosthesis is repaired; the use of cemented prosthesis requires mastery of the technology of cementing.
3. Different femoral stems and their selection
Types of biologically fixed femoral stems and their selection
Biofixed femoral stems can be categorised into proximal, distal and mixed fixation types according to the site of fixation, each with its own advantages.
For first-time replacement patients, the proximal fixation type should be used as much as possible to minimise interference with the distal medullary cavity, which will facilitate revision. According to the geometry of the prosthesis, the biologic stem can be divided into tapered stem, wedge-shaped stem, column-shaped stem, etc. For the initial total hip replacement, try to use tapered stem or wedge-shaped stem. According to the surface coating, the biologic stem can be classified into microporous, hydroxyapatite, sandblasted, etc. The surgeon is recommended to use the biologic stem according to the patient's specific condition. It is recommended that the surgeon choose according to the patient's specific situation and his own experience.
Cemented stem and its selection
Cemented femoral stems are divided into polished and sandblasted according to the surface treatment; anatomical stems, straight stems and curved stems according to the anatomical shape; collarless and collared stems according to the presence of a collar or not; bi-conical and tri-conical stems according to the taper of the prosthesis, and so on. It is recommended that the surgeon make the selection based on the patient's specific situation and his/her own experience.
4. Scenarios of using joint prosthesis
Joint prostheses are mainly used in joint replacement surgeries to replace damaged or diseased joints, restore normal joint function and relieve pain. The following are some common types of joint prostheses and the scenarios in which they are used:
Shoulder prosthesis: It is used in shoulder replacement surgery for degenerative shoulder joint disease, humeral head necrosis, shoulder fracture, rotator cuff rupture and other conditions. Prostheses are usually made of materials such as metal alloys, plastics or ceramics, and are sometimes combined with autogenous bone to restore normal movement and strength to the shoulder joint.
Knee prosthesis: Used in knee replacement surgery for conditions such as degenerative knee disease, rheumatoid arthritis, and traumatic arthritis. Knee prostheses include a femoral component, a tibial component, a patellar component, and sometimes a tibial baseplate component with eccentric pitch and related accessories for better stability and range of motion.
Hip Prosthesis: Used in hip replacement surgeries for conditions such as degenerative hip joint disease, femoral head necrosis, hip fracture, and congenital hip dysplasia. Hip prosthesis is divided into total hip replacement and partial hip replacement, and the materials include metal, ceramic or plastic.
Ankle prosthesis: used for ankle replacement surgery, suitable for degenerative ankle joint disease, traumatic arthritis and other diseases. Ankle prostheses are designed to provide good ankle motion function while reducing wear and loosening.1234
The choice of joint prosthesis and the surgical plan need to be determined by the patient's specific circumstances, such as age, activity level, bone quality, and the surgeon's recommendations. After surgery, the patient will need to undergo rehabilitation to help restore joint function and strengthen the surrounding muscles.
5. Considerations for selecting a joint prosthesis
The selection of joint prosthesis should be considered from the aspects of prosthesis material, patient's age, lesion site and disease type.
1. Prosthesis materials. There are stainless steel, cobalt-nickel alloy, cobalt-chromium alloy, titanium alloy, etc. Among them, titanium alloy is corrosion-resistant, with elasticity modulus similar to that of human bone, easy to be combined with one's own bone, and it is the most widely used artificial joint material in recent years.
2Patient age. The patient's age is also a factor that affects the choice of prosthesis, for example, for elderly patients with femoral head necrosis and femoral neck fracture, they may directly choose total hip or hemi-hip replacement prosthesis, and for elderly intertrochanteric fracture of femur, they may choose cemented bipolar artificial femoral head replacement prosthesis.
3, lesion site. Knee replacement, for example, if the patient's patella lesion, feasible patella articular surface replacement prosthesis. If the patient has a lesion of the medial or lateral condyle, a unicondylar replacement prosthesis is feasible.
6. Customisation of joint prostheses
The customisation of a joint prosthesis involves a number of aspects, including individual needs analysis, imaging assessment and measurement, prosthesis design and manufacture. The following are the main components of customised joint prostheses:
Individualised needs analysis: When customising a joint prosthesis, it is first necessary to have an in-depth understanding and analysis of the patient's specific situation. This includes basic information such as the patient's age, gender, weight, height and occupation, as well as factors such as the degree, cause and duration of the knee injury. This information provides the basic data for designing an individualised joint prosthesis.
Imaging assessment and measurement: Detailed information on the anatomical structure of the joint, such as the shape, size, angle and other parameters of the femur, tibia and patella, can be obtained through imaging methods such as X-ray, CT or MRI. This information is essential for accurate calculation and design of joint prostheses.
Prosthesis design and fabrication: computer-aided design (CAD) software is used to construct a 3D model based on the patient's imaging data, on the basis of which a personalised joint prosthesis is designed and fabricated to meet the patient's actual needs. This process may involve the use of 3D printing technology to enable the precise manufacture of the prosthesis.
Material selection: Material selection for joint prostheses is also an important element. Common materials include metals (e.g., cobalt chromium molybdenum alloy, titanium alloy, etc.), polyethylene (PE), ceramics, etc. The choice of material needs to take into account the patient's activity level, life expectancy and other factors to ensure the durability and biocompatibility of the prosthesis.
Surgical Planning: After the prosthesis has been manufactured, the surgeon will plan the surgery based on the design of the prosthesis to ensure that the prosthesis will be implanted precisely into the patient. This process may involve computer simulation of the surgery to ensure success and reduce surgical risks.
In summary, customisation of joint prostheses is a comprehensive process that requires multidisciplinary collaboration and advanced technology. Through personalisation, it is possible to improve surgical outcomes, reduce the risk of complications and enhance the patient's quality of life after surgery.
Conclusion
In conclusion, the primary role of joint prostheses is to restore joint function and reduce pain. By understanding the definition, classification, usage scenarios, considerations for selecting a joint prosthesis, and customisation options, buyers and distributors can make informed decisions.
