Hip joint replacement is a surgical operation performed to restore mobility and relieve pain in patients diagnosed with severe arthritis or those experiencing severe pain after an injury. This treatment, also called hip arthroplasty, is prevalent and effective. However, patients must choose an implant to receive during the operation from the several options available in the medical industry. The type of implant you choose will determine the speed of your recovery and how well and healthy your joint will be after treatment.
Working with the best hip joint replacement experts is beneficial as you understand how these implants work, which can help you make informed decisions. The experts also ensure you know what the treatment process is like and what to expect afterward, which can help you be mentally prepared.
Here are the main categories of implants used in hip joint replacements and their pros and cons to help you make the right choice:
Femoral Stems
Femoral stem implants feature an artificial ball component, which a medical expert anchors into your femur or thigh bone during surgery. The stems usually have varied fixation designs and lengths to match the different bone anatomy on where they are fixed. They must also be adequately fixed to ensure stability. Examples of femoral stem implants you can easily find in the industry today include the following:
Cemented Femoral Stems
This is a very common implant used in hip replacement surgeries. The implant uses bone cement to attach its stem to a femoral canal. The cement mantle, a unique characteristic of this implant, offers stability to your joint after replacement. This gives you a long service period after the surgery.
During surgery, the surgeon first broaches your femur and prepares the canal to receive the implant. Broaching creates a channel on the femur for the implant's insertion. Once the bone is ready to receive the implant, the surgeon inserts vacuum-mixed cement into the canal to create an anchor for the implant. They then insert the stem into the canal with the assistance of a centralizer. The surgeon will then pressure the cement to ensure the stem is anchored well in the canal.
Cemented femoral stems work very well for patients whose bone quality is compromised by arthritis. Your doctor will first determine the health of your bone to recommend the best implant for your hip joint replacement. The cement the surgeon uses gives them additional flexibility to position the implant.
However, the surgeon must consider other factors to ensure your hip joint replacement with a cemented femoral stem succeeds. Some of these factors include the following:
- The quality of the stem used — The surgeon must mix the cement and insert it according to the recommended standards
- The cement’s setting time — The surgeon must be able to determine the right setting time for the cement according to the humidity and temperature of the treatment room
- Bone cement implantation syndrome — This is a rare but fatal complication that happens during hip joint replacements. Some of the symptoms the surgeon must watch out for during the operation include low oxygen levels, low blood pressure, and cardiac arrest. The surgeon must closely monitor you during the surgery to avoid such complications.
Your choice of hospital or surgeon for hip joint replacement surgery is critical for effective implant placement and to avoid complications.
Note: Cemented femoral stems are removable. Your surgeon can use osteotomes to break the cement and stem interface. They can then remove any remaining cement with reverse hooks and cement removal osteotomes. This information can help if you want to change to a different implant during treatment.
The advantages of cemented femoral stems include the following:
- The cement makes this implant stabilize quickly after installation, allowing you to recover and regain your mobility quickly
- They lower a patient’s risk of periprosthetic fracture because of their stability
- They are beneficial for patients with reduced bone density due to medical conditions or age
- These implants are straightforward to install by surgeons
However, you should also consider the cons of these implants to make a more informed decision. They include the following:
- The cement can loosen over time, making the implant unstable and affecting mobility. You will need to revisit your surgeon for a revised surgery.
- Be aware of stress shielding, too. In this condition, the bone around the implant loses its ability to load naturally, which could result in further bone loss.
- These implants are unsuitable for young or active patients because of the implant’s likelihood of loosening over time.
- Your risk of infection after implant placement is high because of the cement used.
Cementless Femoral Stems
These types of implants do not need cement during hip replacement surgery. They are usually made from materials like cobalt-chrome molybdenum or titanium aluminum vanadium. Surgeons rely on the strength of your bone when installing cementless implants, hoping that the implant's contact with your natural bone will create the stability needed to restore your mobility and keep you moving for years. Thus, they install the stem in an osseous ingrowth for long-term stability.
The modern designs of cementless femoral stems do not loosen up over time, like their cemented counterparts. They also do not cause you thigh pain after installation. These are what make these types of implants more popular today. They also have more longevity than other implants, making them more reliable and cost-effective.
However, you can carefully choose the material you prefer for a cementless stem, as this choice affects its overall performance. Typically, Ti-AIV is biocompatible, which makes it more popular than CocrMd. It also has a lower modulus of elasticity, which keeps it stable over the years. You must also choose the stem design you prefer for better performance. Your surgeon will discuss the method and geometry of the initial installation, which vary from one step to the next.
Your choice of stem material will also depend on your age. Cementless implants are generally associated with younger and active adults because of their lower risk of loosening over time. People who have needed revised surgery with these types of implants are 75 years or older.
Additionally, you need a highly skilled and experienced surgeon for the quality and effective installation of a cementless femoral stem. Your surgeon's expertise will significantly determine your implant's performance after installation.
Here are the pros to consider during decision-making:
- Cementless stems have a porous surface that encourages the natural growth of the bone around the implant. This creates a natural anchor for the implant, which keeps it stable for years, regardless of how active you are after treatment.
- Cementless stems also preserve your bone density due to the implant-to-bone contact in their installation. Your bone continues to grow, which provides a more stable hip joint after treatment.
- These implants function very well for younger and active patients who are about to lose hope after arthritis or injury to their hip joints.
- The risk of infection and allergic reactions is lower for patients who receive cementless implants than those who receive cemented implants.
Here are some cons to consider, too:
- Stress shielding is possible with cementless implants if the implant transfers a different load than what the natural bone bears. This results in bone loss around the implant, which could affect its stability in the long run.
- A cementless implant installation requires an expert for precise placement to encourage maximum contact between your natural bone and the implant. Without that precision, reduced contact can affect the stability of the implement and your mobility in the long run.
- Patients receiving cementless stems have a higher risk of periprosthetic fracture, especially when the quality of natural bone is poor. The fracture can occur around the implant, requiring additional surgery.
- Installing a cemented stem can take longer as the surgeon seeks to achieve a precise implant-to-bone contact.
- This implant is not suitable for all people, especially elderly patients who have suffered significant bone loss due to old age.
Hybrid Femoral Stems
This type of implant combines the elements and benefits of cemented and cementless stems in hip joint replacements. Specifically, the surgeon uses a cemented femoral part and an uncemented acetabular part during treatment. This combination creates an implant suitable for everyone, including the elderly. It also works very well for patients with low bone density and younger or active patients who need a stable and long-lasting hip joint replacement after an injury or disease.
During the installation, the surgeon press-fits the stem into the patient’s femoral canal. They then use bone cement to hold the implant in place by pressurizing it into the pockets created in the implant’s metaphyseal region. With time, the patient’s bone will grow to form an extra anchor for the implant, providing the stability you need to enjoy for a very long time.
Due to this implant's combination of cemented and cementless elements, there is usually a high survival percentage. This is what makes hybrid stems very popular today.
Implant Types According to Bearing Surfaces
In hip joint replacements, bearing surfaces are the contact points between the ball and socket of an implant. These contact points are usually made from various materials, including ceramic, metal, or cross-linked polyethylene. The metal-on-polyethylene option is the most common one today. However, some patients also choose ceramic-on-ceramic, while others opt for metal-on-metal combinations. Your choice mainly depends on the particular implant design you have in mind and your medical needs. All the combinations have benefits and disadvantages, which you must understand to make an informed decision.
Metal-on-Polyethylene Implants
This implant type is characterized by a metallic femoral head (the artificial joint where the ball is) and a socket lining made from a polyethylene material. In this case, the metal design is typically made from an alloy of cobalt and chromium, while the plastic material is usually a metal-on-plastic design. Metal-on-polyethylene is a typical hip replacement, although newer designs like ceramic-on-ceramic are slowly replacing it. Your surgeon will consider your needs, age, and other factors, like your budget when recommending this type of hip joint replacement.
Metal-on-polyethylene implants offer several benefits to a patient, including the following:
- It is an inexpensive option, particularly for patients working on a strict budget
- It is strong and durable, offering you a long time of service before requiring a replacement
- The implementation is also easy and quick to create and place, which translates to a reduced treatment time
However, you should also consider the cons when making a choice. For example, the metal element of this implant can wear out against the plastic material, resulting in wear debris or small particles. These particles irritate the surrounding tissues, resulting in bone loss or osteolysis around the implant.
There is also the risk of metal ions released from the implant, which could penetrate the body and cause an adverse allergic reaction in the patient.
Ceramic on Polyethylene Implants
A polyethylene socket and a ceramic ball characterize these implants. They are an excellent option and highly recommended to patients sensitive or allergic to metallic implants. You can also choose this option if you need an alternative to an all-plastic implant. When designing this implant, medical professionals make a rigid and smooth ceramic head to reduce friction in the hip socket. The ceramic has natural lubricating properties, which help to minimize friction and subsequent irritation. A ceramic head also hardens after placement, reducing friction at the bearing point.
Ceramic-on-polyethylene implants are becoming very popular today because of their safety and strength. Ceramic is an inert material least likely to trigger biological reactions in a patient’s body. Thus, your risk of experiencing irritation and subsequent bone loss is lower. Here are other benefits you will enjoy after receiving this implant:
- It will be safe for you in the long run if you are sensitive or allergic to metal
- There will be minimal wear and tear at the socket, keeping you comfortable and free from adverse effects like loss of bone density.
- Ceramic-on-polyethylene implants also come in varying designs that you can choose from
Ceramic on Ceramic Implants
These implants are characterized by an exclusive use of ceramic on all their bearings instead of a combination of ceramic with metal or polyethylene. They are strong, durable, and a safe choice for most patients. Since the ceramic material does not quickly wear out, your all-ceramic implant remains sturdy and stable for a very long time. With metallic implants, you are also safe from daily irritations and discomfort from wear and tear. Some of the benefits these implants offer include the following:
- Reduced wear at the bearing surface because the ball and socket are both made from a ceramic material, which does not quickly wear down
- The implant will likely serve you long because of reduced wear.
- Your overall well-being is safe since the implant does not release debris to the body, which could material an allergic reaction or infection.
However, complications could occur with a ceramic-on-ceramic implant. For example, the bearing surface can continually produce a squeaking sound due to reduced lubricating fluid, which can be uncomfortable or embarrassing.
You can also suffer a ceramic fracture, especially if you are obese, overly active, or suffer a trauma like a fall or accident. This will necessitate an immediate removal and replacement of the implant.
Doctors recommend ceramic-on-ceramic implants for young, athletic patients who wish to continue active after treatment. However, for more informed decision-making, you should consider the benefits and possible complications.
Metal-on-Metal Implants
This implant has a metallic femoral head and an acetabular cup. It creates a bearing surface where two metals rub against each other as you move. Although these designs are not very popular, some people choose them for the benefits they offer. For example, their initial designs had larger metallic ball sizes and a reduced wear risk, making them suitable for active and younger patients.
However, some patients have reported metallosis. This is a problem whereby the implant loses some metallic particles due to continued friction at the hip joint. The particles irritate the joint, resulting in pain. They also put the patient at risk of inflammation, infection, and other related complications.
Due to these and other complications, metal-on-metal implants are not as popular as other options. Due to continued friction, you will likely require revision surgery as soon as the implant wears out. You could also require close monitoring by your doctor because of the increased metal ions in your body.
Find a Skilled Hip Joint Replacement Surgeon Near Me
A painful hip joint will likely require a replacement to relieve the pain and restore mobility. Whether the pain results from arthritis or injury, your doctor can diagnose and recommend the most suitable hip joint replacement. They will also discuss your treatment options and help you choose the most appropriate implant.
At Lamis, we are experts in hip joint replacement surgeries in Los Angeles. Our highly skilled and experienced surgeons are ready to diagnose and discuss the best implant options for your pain and mobility. Call us at 310-734-6088 to discuss your needs, options, and our services in detail.
