Elbow Arthroplasty

Overview

Total elbow arthroplasty has progressed over time.  Elbow implants can be linked or unlinked. Unlinked implants are appealing to patients with reasonably well maintained bone stock and ligaments, but linked implants are preferred by many because they minimize instability and allow replacement for a broader range of purposes.

Rheumatoid arthritis and other inflammatory arthropathies are the most common reasons for elbow arthroplasty. Posttraumatic osteoarthritis, acute distal humerus fractures, distal humerus nonunions, and repair following tumor removal are now among the indications.

Elbow arthroplasty is very successful in terms of pain relief, motion and function. However, its complication rate remains higher than arthroplasty of other joints. The overall success rate is best for patients with inflammatory arthritis and elderly patients with acute distal humerus fractures, worse for patients with posttraumatic osteoarthritis.

The most common complications of elbow arthroplasty include infection, loosening, wear, triceps weakness and ulnar neuropathy. When revision surgery becomes necessary, bone augmentation techniques provide a reasonable outcome.

What elbow joint consists of?

The elbow is a hinge joint which is made up of three bones: 

1. The humerus (upper arm bone).
2. The ulna (forearm bone on the pinky finger side).
3. The radius (forearm bone on the thumb side).

Causes of elbow pain necessitating Elbow Arthroplasty

Inflammatory arthropathies, such as rheumatoid arthritis, are the most common reasons for elbow arthroplasty.  Furthermore, the polyarticular nature of these disorders, along with a modest rate of wear and loosening, may limit the total activity level of these individuals. There is generally adequate bone stock and ligamentous integrity in the early stages of rheumatoid arthritis to allow the use of unlinked implants. 

The success of elbow arthroplasty in the treatment of inflammatory diseases inspired its usage in the treatment of additional conditions. One of the most challenging disorders to treat is posttraumatic elbow osteoarthritis. Alternative surgical methods, such as interposition arthroplasty, may help some individuals, although pain relief is not fully reproducible, and some patients may develop postoperative instability. Elbow arthroplasty results in a more consistent outcome, but these younger, more active patients are more likely to experience mechanical failure early on. Elbow arthroplasty is generally avoided in people under the age of sixty. 

Several conditions can cause elbow pain and disability, and lead patients and their doctors to consider elbow joint replacement surgery: 

1. Rheumatoid Arthritis: The synovial membrane that covers the joint becomes inflamed and swollen in this condition. Chronic inflammation can harm cartilage, resulting in cartilage loss, discomfort, and stiffness. Rheumatoid arthritis is the most common form of a group of disorders termed "inflammatory arthritis".
2. Osteoarthritis (Degenerative Joint Disease): Osteoarthritis is a kind of arthritis that develops with age and is characterized by "wear and tear." It mainly affects persons over the age of 50, although it can also affect younger people. The cartilage that cushions the elbow bones shrinks and wears away. The bones then grate against one other. The elbow joint stiffens and gets uncomfortable over time.
3. Post-traumatic Arthritis: This type of arthritis can develop as a result of a severe elbow injury. Fractures of the bones that make up the elbow, as well as tears of the surrounding tendons and ligaments, can cause articular cartilage degradation over time. This creates discomfort and inhibits the function of the elbow.
4. Severe Fractures: Another typical reason for elbow replacement is a serious fracture of one or more of the bones that make up the elbow. If the elbow is shattered, it may be difficult for a doctor to reattach the bone fragments. Furthermore, the blood flow to the bone fragments may be disrupted. In this scenario, a surgeon may advise an elbow replacement. The elderly with osteoporosis (fragile bone) are the most vulnerable to serious elbow fractures. Furthermore, some fractures may not heal adequately and may necessitate an elbow replacement to address ongoing issues. In several countries, acute comminuted distal humerus fractures in older patients or those with prior articular degeneration have emerged as one of the most prevalent reasons for elbow arthroplasty. In these cases, stable internal fixation is difficult to establish, whereas arthroplasty is utilized effectively for other fractures (femoral neck, proximal humerus). It is critical to note that this is a selective indication, as the majority of patients with distal humerus fractures benefit with open reduction and internal fixation.
5. Joint instability: Instability occurs when the ligaments that hold the elbow joint together are damaged and do not work well. The elbow is prone to dislocation. Chronic instability is most often caused by an injury.

Types of Elbow Implant 

There is considerable misunderstanding about the many types of implants available to replace the elbow joint. In general, there are two types of implants that differ by the presence or absence of a mechanism that links the humeral and ulnar components. A common misconception is to equate linking to constraint: some unlinked implants are more constrained than their linked counterparts.

Linked/Coupled Implants:

The physical linking of the humeral and ulnar components during surgery to avoid subluxation or dislocation events is the unique feature of this form of implant. Early linked implants had restricted hinges that could only bend and extend. These implants have a significant failure rate due to excessive pressures being transmitted to the implant-cement-bone contact and other design flaws. Most linked implants are now semiconstrained: their connecting mechanism acts like a sloppy hinge, allowing for some rotational and varus-valgus motion. Semiconstrained implants are thought to convey less stress to implant surfaces, resulting in more dependable long-term fixation when combined with other design enhancements. The Coonrad-Morrey prosthesis is the most often used linked semiconstrained implant today. The humeral component is porous-coated distally and has an anterior flange, which boosts the implant's rotational stability and neutralizes extension forces imparted to the implant interface. The advantage of an anterior flange has been studied for other implants as well. The proximal part of the ulnar component features a plasma-spray metallic covering. Polymethylmethacrilate is meant to be used to fix both components. The components are joined by a cobalt-chrome axis Pin, which articulates with the polyethylene bushings of the ulnar and humeral components, allowing for about 10 degrees of varus-valgus and rotational laxity.

Unlinked/Uncoupled Implants:

The components of this kind of arthroplasty are not mechanically linked. The proper positioning of each component, ligamentous integrity, and the dynamic stabilizing influence of the muscles all contribute to the maintenance of prosthesis congruency. The majority of these implants provide anatomic resurfacing of the distal humerus and proximal ulna; few include a radial head component. The Souter-Strathclyde and Kudo prostheses are the most popular unlinked implants.

Advantages and Disadvantages of the different kinds of elbow implants

The clinical outcome and long-term survivorship vary per implant, and the findings achieved with a specific linked or unlinked implant cannot be generalised to other members of the same implant family. However, each of these two design approaches has its advantages and disadvantages. 

Linked Elbow Implants:

Preoperative planning for Elbow Arthroplasty 

1. Medical Evaluation: If you decide to have elbow replacement surgery, your orthopaedic surgeon may request that you arrange a complete physical examination with your primary care physician several weeks before the procedure. This is required to ensure that you are in good enough health to have surgery and recover fully. Before surgery, many patients with chronic medical issues, such as heart disease, must be assessed by a specialist, such as a cardiologist.

2. Medications: Make sure to inform your orthopaedic surgeon about any drugs you are taking. Some drugs may need to be discontinued prior to surgery. Over-the-counter medications, for example, may cause severe bleeding and should be discontinued two weeks before surgery: Non-steroidal anti-inflammatory medications, such as aspirin, ibuprofen, and naproxen sodium Most arthritis medications If you take blood thinners, either your primary care doctor or cardiologist will advise you about stopping these medications before surgery.

3. Home Planning: Making simple changes to your house before surgery might help you recover more quickly. It will be difficult to reach high shelves and cabinets for several weeks following your operation. Before your procedure, walk around your house and put any objects you might need later on low shelves. When you get home from the hospital, you will want assistance with daily duties such as dressing, bathing, cooking, and laundry for a few weeks. If you will not have any help at home soon following surgery, you may require a brief stay in a rehabilitation center until you are more self-sufficient. 

How Elbow Arthroplasty is performed? 

1. Surgical Exposure: The majority of surgical methods utilized for elbow arthroplasty implantation necessitate mobilization of the elbow extensor mechanism. Most surgeons do subcutaneous ulnar nerve transposition on a regular basis. The triceps-reflecting Bryan-Morrey method is the author's preferred exposure; some surgeons prefer to divide the triceps or employ an extended lateral-sided Köcher approach. Triceps-preserving techniques are preferred wherever possible. Bryan and Morrey's method entails separating the triceps from the olecranon and reflecting it from medial to lateral while retaining continuity with the anconeus and forearm fascia. This method exposes the joint well and enables for a stable restoration of the extensor mechanism, although it is accompanied with a risk of lateral triceps subluxation and extension weakness. A good exposure can also be obtained by splitting the triceps in the midline and detaching its medial and lateral portions from the olecranon. The primary advantage of this method is that the extensor mechanism is kept localized over the olecranon, although transmuscular procedures are less attractive in general, and restoration of the medial portion is sometimes inadequate. In rare cases, it may be able to complete the replacement by working on both sides of the triceps. This method is most commonly used when there is a significant bone defect at the distal humerus (due to trauma or tumor removal), as well as in acute distal humerus fractures and distal humerus nonunion, where the distal fragments are removed.

2. Bony Preparation and Component Insertion: The bone preparation varies depending on the system. The majority of the components are stemmed and must be prepared using rasps and broaches in the humeral and ulnar canals. The humeral canal is discovered and utilized as a guide to cut a yoke-shaped portion of the distal humerus to accommodate the humeral component's distal half. The canal is then prepared to take the stem, and the anterior cortex of the distal humerus is exposed for eventual contact with a bone graft implanted below the humeral component's anterior flange. The ulnar canal is opened in the middle of the trochlear notch and prepared with either right or left broaches. The components are then cemented together using antibiotic-loaded polymethylmethacrylate, followed by the placement of a bone graft between the anterior humeral cortex and the humeral flange. After that, the components are joined together.

What happened after surgery?

Recovery:

Your medical team will give you several doses of antibiotics to prevent infection. Most patients are able to eat solid food and get out of bed the day after surgery. You will most likely stay at the hospital 2 to 4 days after your surgery.

Pain Management:

You will have some pain following surgery. This is a normal component of the recovery process. Your doctor and nurses will attempt to minimize your pain, which will allow you to recover from surgery more quickly. Medications are frequently recommended for short-term pain management following surgery. Opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), and local anesthetics are just a few of the medications available to aid with pain management. Your doctor may prescribe a combination of these drugs to alleviate pain and reduce the need for opioids. Be aware that, while opioids can help with pain relief after surgery, they are a narcotic and can be addictive. Opioid addiction and overdose have become major public health concerns in the United States. It is critical to utilize opioids only as prescribed by your doctor. Stop using opioids as soon as your pain begins to improve. Consult your doctor if your pain does not improve within a few days following your procedure.

Rehabilitation:

A well-planned rehabilitation program is essential for the success of an elbow replacement. You will be given basic exercises for your hand and wrist to help prevent stiffness and edema. As the incision heals, you will perform modest elbow range-of-motion exercises. Your doctor may prescribe treatment or instruct you on how to perform the exercises on your own. You won't be able to put any weight on your arm or push against resistance with your hand for at least 6 weeks following your operation.

Is Elbow Arthroplasty risky? 

Your orthopaedic surgeon will describe the possible risks and consequences of elbow joint replacement surgery, including those connected to the operation itself as well as those that can develop thereafter.

The majority of issues may be effectively handled. The following sections discuss potential problems.

Infection:

Infection is a risk with every operation. Infection can form in the incision or deep around the prosthetic components of an elbow replacement. It might happen while you're in the hospital or after you leave. It might happen years later. Any infection in your body has the potential to spread to your joint replacement.

Antibiotics are commonly used to treat minor infections in the wound area. Major or deep infections may necessitate further surgery and component removal.

When undergoing an invasive operation, such as surgery or dental procedures, consult with your doctor about receiving an antibiotic prescription. These operations result in the brief release of microorganisms into your circulation, which might lead to an infection in the replaced joint.

Implant Problems:

Despite advances in implant designs and materials, as well as surgical methods, the implant may wear out and the components may become loose. The plastic liner (known as the bushings) might wear out and must be replaced. Excessive wear, loosening, or implant fracture may necessitate further surgery (called a revision procedure).

Nerve Injury:

Nerves near the joint replacement may be injured during surgery, although this is an uncommon complication. These nerve injuries usually heal on their own over time, without the need for therapy.

Wound Healing:

It is important to carefully protect your incision to avoid wound healing problems.

Long-term outcomes of Elbow Arthroplasty

The majority of patients reported an improvement in their quality of life following complete elbow replacement surgery. They have reduced discomfort, better motion and strength, and better function. 

You should anticipate to perform all basic daily activities such as obtaining a plate from a cupboard, making dinner, lifting a milk jug, styling your hair, basic hygiene, and clothing. Discuss with your doctor which activities you should avoid, such as contact sports and activities that have a high risk of falling (such as horseback riding or climbing ladders), as well as heavy lifting. These factors enhance the likelihood of the metal pieces loosening or fracturing, as well as the bone shattering. 

Be prepared for extra security screening while traveling. During the security check-in, there is a potential that your metal implant will set off the metal detector. 

Inform the security officer ahead of time that you have an elbow replacement and have a medical identity card to make the check-in process go more easily. Although this does not alter the screening standards, it will assist the security officer in determining the nature of the alert. Expect the security officer to use a wand scanner and maybe check your arm in a private place to view the scar. The new body scanners can detect joint replacements, eliminating the need for additional individual screening. 

Conclusion

Elbow replacement arthroplasty is constantly evolving. Although it was first used mostly in patients with inflammatory arthritis, its indications have now been broadened to include additional conditions that place greater demands on the implants and appear to result in higher failure rates. Elbow arthroplasty has certain distinct characteristics. 

The elbow joint is small in comparison to the hip and knee joints, and its stability is heavily dependent on ligamentous integrity. In the United States and Central Europe, linked semiconstrained elbow arthroplasties became popular; these intrinsically stable implants raise concerns about higher contact pressures on the already thin polyethylene. Unlinked arthroplasties, which are common in the UK and Asia, may have superior tribological qualities but are prone to instability and limited elbow extension. 

The necessity to violate the extensor mechanism for exposure, the increased risk of infection, the involvement of the radial head, and potential clinical complications associated to the ulnar nerve all complicate elbow arthroplasty. Linkable implants, alternate bearing surfaces, uncemented fixation, distal humerus hemiarthroplasties, unicompartmental arthroplasties, implantation with computerized navigation systems, and enhanced revision methods are examples of current and future developments.