Advances in wrist replacement surgery may improve outcomes

2021-11-25 03:14:48 By : Ms. Kaki Huang

Traditionally, wrist fusion has become the gold standard for pancarpal wrist arthritis due to its low complication rate, pain relief and good durability.

But according to published literature, one of the disadvantages of wrist fusion is that it eliminates radial carpal movement.

Eric R. Wagner, MD, of the Upper Limb Center at Emory University, told Orthopedics Today: "It's like you have a permanent cast." "So, you Your fingers will become movable fingers, and now you [must] adjust your shoulders to compensate for this. It will put more pressure on the rest of the limbs, and will... put pressure on your fingers. It does not It's as simple as your wrist movement."

In contrast, sources who spoke to Orthopaedics Today said that total wrist arthroplasty (TWA) not only relieves pain, but also keeps exercise.

"This is not a normal exercise because the native wrist is quite complicated," Brian D. Adams, MD, professor of plastic surgery at Baylor College of Medicine, told Plastic Surgery Today. "The multiple joints in the wrist produce the motion we usually do on the wrist, and the wrist replacement simplifies the wrist joints, so it can only provide about 50% of the normal wrist motion range."

However, Adams said that 50% of the wrist range of motion is all that is required for most functional activities in daily life, and most patients are not aware of the limitations of wrist motion.

Arnold-Peter C. Weiss, MD, Brown University professor, vice chairman and director of hand surgery, said that patients don’t like the idea of ​​fusion surgery. They tend to choose that."

"Wrist fusion does have good power, so there are some advantages, but usually patients want to be as'normal' as possible, which means they want to exercise," said Weiss, who has been in TWA for 25 years, about every year. 25 to 40 cases.

Wagner said that, like other arthroplasties, before patients undergo wrist arthritis surgery, they must first try non-surgical options, such as splinting, injections, and strengthening, followed by joint stabilization by a hand therapist.

Weiss said that once a patient develops osteoarthritis in one or two wrist joints, physical therapy will not have any effect.

"This is basically a mechanical problem," Weiss told Orthopaedics Today. "It's the ossification of the ossification. You can't exercise like this. It's not like a muscle, where you can make it stronger. If you do that, it will only hurt people more."

Weiss said that many patients with wrist arthritis only develop in some small joints of the wrist, which makes them candidates for partial surgery that can reduce pain and maintain movement.

Wagner said that some of the partial surgeries that have been found to provide good results include quadrangular fusion, radioscapho-lunate fusion, proximal carpal resection, and partial nerve resection. Wagner said that although these partial procedures can help in the short term, many studies have shown that in the long run, a large proportion of patients still suffer from arthritis.

"Although you helped them in the first 5 or 10 years, their wrists usually develop arthritis in the previously spared joints, causing pain and limiting their function," Wagner said in the past. These programs and TWA have been extensively studied in the past few years. The past ten years.

Although some operations to treat wrist arthritis are good operations in the short term, Wagner said that the surgeon's investment in the development and use of these procedures "eliminates the need for innovation in overall wrist replacement."

"However, when it comes to knee and hip joints, there is no other option other than replacements, which financially drives better investment in hip and knee replacements," he said. "Ultimately, in the past 30 years, we have obtained better implant technology and improved surgical techniques. On the wrist side, it has been greatly delayed due to these other reasonable options developed by our mentors and founders. "

According to A. Lee Osterman, MD, Professor of Hand Surgery at Thomas Jefferson University and Chairman of the Philadelphia Hand and Shoulder Center, TWA is a highly technically demanding procedure.

"Usually, the deformation of small bones means that you cannot use prefabricated jigs with great predictability, because jigs suitable for normal arthritic wrists will not be suitable for wrists that have been eroded by arthritis." Sterman, said it.

Robin Kamal, Associate Professor of Plastic Surgery, MD, and MBA at Stanford University, said that surgical planning and technology are essential to prevent complications. Surgical planning can solve problems such as how much bone to remove, manage limited bone volume and Implant fixation and other issues.

"In a similar way, incision planning for implant positioning, wrist soft tissue balance, and/or soft tissue enhancement is essential to ensure the stability of the implant," Kamal, who has completed about one or two TWAs Case. One of the past 7 years, tell Orthopaedics Today. He said that proper fixation of the distal stem of the implant to the carpal and metacarpal bones can also prevent complications.

Even with a good surgical plan, a source who spoke to Orthopedics Today said that complications may occur.

According to Wagner, one complication in patients undergoing TWA is dislocation.

"For the previous generation of implants, this is a more relevant risk compared to the recent fourth generation implants. In addition, if you place the prosthesis properly, not tightly, but tight enough for intraoperatively When you put pressure on the joints, move your wrists in extreme motions during the trial, and perform a sturdy rucksack repair, you will not be at risk of [dislocation] If necessary, with retinal enhancement, you can reduce the risk of [dislocation] to not a major problem Place," Wagner said.

Kamal said that although uncommon, infections can occur in TWA cases.

Similar to other joint replacement surgeries, Adams said there is a risk of loosening, which may be related to the technical aspects of the surgery, the patient's bone quality, and the extent to which the patient uses the wrist. He said particle disease is another problem of TWA.

"Osteolysis caused by granular disease does occur and may lead to synovitis and eventual loosening," said Adams, who has been performing TWA with approximately 10 to 15 cases per year since 1996.

Adams said that implant design is sometimes associated with complications. However, he said that the design of the full-wrist implant has evolved a lot since the first generation and is still evolving. The newer design provides more lasting results for active patients.

"Specifically, we no longer rely on the long handle to be fixed in the metacarpal bone, but in the carpal bone," Adams said. "To help promote this fixation, we perform wrist fusion while implanting. So, our goal is to replace the surface as close to the inside of the wrist as possible, not to extend the fixation outside the wrist, so I think durability Increased, the morbidity rate is reduced, and if any final repair surgery is required, it is simplified."

Sources who spoke with Orthopedics Today said that the combination of improved surgical techniques and the design of wrist replacement implants may continue to extend the life of TWA surgery.

"Historically, the literature shows that by 10 years, about 50% of patients will have some complications from TWA. Therefore, [the ratio] is relatively high compared to total hip or total knee," Kamal said . "The more modern literature shows that as we get better at implanting these alternatives and technology advances, the rate of complications is declining."

However, according to sources, there is still room for improvement in future implant designs, and the biggest innovation is better carpal fixation.

"There are several ways to do this, but one of my favorite methods is better locking techniques to improve the fixation of the distal components, including actually locking the screws to the distal bone plate so that they are on the plate and There is a fixed angle structure between the screws, which improves rotational stability and micro-movement. This is similar to the early improvement of the reverse shoulder arthroplasty floor. In addition, a larger surface area or better piles are used to optimize Ingrowth can continue to improve the difficulty of distal component fixation," Wagner said. "The combination of locking screw technology and better posterior technology into the carpal bone will be huge. It provides us with more real fixed angle structures, with three fixed points between the bone plate and the screw/post for the carpal bone The far end of the component is fixed."

Ostman said that one area of ​​research that may translate into the wrist in the future is osseointegration, which involves fixing the prosthesis directly to the bone.

"If we can do this by applying prostheses, some of these techniques may eventually be suddenly applied to the wrist without specifically targeting the wrist." Osterman started total wrist arthroplasty in 1995, which is performed every year. About 20 cases, tell today's orthopedics. "Once this happens and we can maintain a good distal fixation, I think you will see more and more wrists being put in."

Weiss said that researchers have already had the idea of ​​using double joints in implants to bring them closer to the anatomical wrist, but this requires a lot of research to get FDA approval.

"How long does it take for it to become an implant, I think it will take a while," he said.

Kamal said that future research should not only focus on improving TWA technology, but also determine which patients can benefit the most from full-wrist implants.

Since TWA is to maintain movement, relieve pain, and maintain or improve function, Osterman said it is commonly used in patients with advanced wrist arthritis, such as osteoarthritis, late collapse of the scapho-lunate bone, and late collapse of the scaphoid nonunion wrist arthritis.

"We have traditionally used it for rheumatoid arthritis, but given the amazing effects of biologics, we are seeing fewer and fewer patients with severe rheumatoid arthritis who need to be replaced," Osterman said.

Wagner said that with improvements in rheumatoid arthritis treatments, as well as improvements in wrist implants and results, the indications for TWA have begun to expand.

Weiss said that surgeons are now performing more total wrist replacements for patients with OA and post-traumatic arthritis.

"I used to do 95% wrist fusion for osteoarthritis or post-traumatic arthritis, and today, for severe cases, I am doing 80% to 90% wrist replacement instead of fusion," he said .

Although surgeons may prefer to perform TWA on the patient's non-dominant hand to improve durability, Adams said there may be greater benefits when performing surgery on the more easily movable wrist. He said that older patients with lower physical needs are often ideal candidates for TWA, so they will not cause excessive wear to the implant.

Adams said that in contrast, young patients with high wrist mobility requirements may experience early prosthesis loosening.

"Maybe there is no designated manual worker, and there may be no designated people involved in daily sports," Adams said. "However, I think golf is still allowed if moderately, but, for example, if the patient is an aggressive person who exercises in the gym and does weightlifting, push-ups, and pull-ups, they may not be a good candidate. "

He said that patients with severe wrist deformities may be contraindications to TWA, but the surgeon can plan how to deal with mild to moderate deformities during the surgical plan.

"For example, if you have had previous surgery or had a lot of erosion, the overall height of the wrist may have been reduced. In this case, more radius resections are needed to make room for the implant," Adams said. "We try to avoid excessive or increased resection on the carpal side, because this is the side most likely to loosen."

Kamal said that patients with poor bone mass may not be able to use TWA to maintain implant stability.

However, Weiss said that patients with a history of infection or lack of good muscle control or adequate tendons are not suitable.

"The wrist implant is just a static implant, so you need good tendons and good muscle control to make it function properly," Weiss said. "If you don't have that, it's not a good idea."

Despite the complexities associated with TWA, if done correctly, Adams said that the vast majority of patients report being satisfied with their wrist replacement, with good pain relief, adequate activities of daily living, 80% to 85% of normal wrist strength and dexterity , Allowing fine motor and other activities.

"Our patients report results have been very good. When comparing them with wrist fusion, quality of life indicators show that wrist replacement is better than wrist fusion," Adams said.

According to Osterman, before considering TWA, surgeons should consider the patient's postoperative expectations.

"If someone says,'I'm going to play golf, doctor. I'm going to retire, so I need that wrist.' That wrist can't keep 18 holes 3 days a week. So you must finally think carefully about inserting [wrist into ] Object," Osterman said.

Wagner said that patients should be educated to understand what the different surgical options are and the advantages and disadvantages of each.

"It needs to be emphasized that although we believe that [total wrist replacement] is a greatly improved type of surgery, in the long run, the risk of complications is traditionally high. If there is no treatment for the latest generation of implants With these studies, it is difficult to say what will happen to their wrists and how many will stand the test in the long run, especially among younger or more demanding patients," he said.

Similarly, Adams said that for surgeons interested in performing this complex operation, proper training in TWA is key.

Adams said: "We know that most newly introduced surgeries have a certain degree of complexity and nuance, and of course it helps to train [surgeons] to understand these are helpful." "For most surgeons, cadavers The seminar is helpful. I think a lot can be gained by actually implementing the procedure, not just reading the manual or watching the video."

Weiss said the surgeon can also visit another surgeon with extensive experience in TWA, or take a hands-on course to learn some skills before performing the operation.

“The same goes for hip replacements, knee replacements, and shoulder replacements. The little things that make surgery easier, these are things you need to know before you feel comfortable,” he said.

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