Wrist fusion, also known as arthrodesis surgery (joint fusion), is a significant procedure that can dramatically improve the lives of those suffering from severe wrist pain or instability. This operation involves joining the carpal bones and the radius to eliminate movement in the wrist joint, providing relief from conditions like posttraumatic arthritis or persistent joint issues. While it may seem drastic, wrist fusion surgery has become a crucial option for patients who have exhausted other treatment alternatives.

This comprehensive guide aims to shed light on the intricacies of wrist fusion, from the surgical process to recovery and rehabilitation. We'll explore the reasons why someone might need this procedure, the techniques used during the operation (including the use of screws and bone grafts), and what to expect during the postoperative period. Additionally, we'll discuss the potential outcomes, including the impact on wrist function and flexion-extension capabilities, as well as strategies to manage potential complications like nonunion.

Understanding Wrist Fusion

What is wrist fusion?

Wrist fusion, also known as wrist arthrodesis, is a surgical procedure that joins the bones in the wrist. This operation aims to reduce pain and increase grip strength by immobilizing the wrist joint . The procedure can involve fusing the entire wrist or only a portion of it, depending on the patient's specific condition.

Indications for wrist fusion

Wrist fusion surgery is primarily used to treat severe arthritis when other non-surgical treatments have failed to provide relief. The most common indications include:

Rheumatoid arthritis
Traumatic arthritis -Scapholunate advanced collapse (SLAC), Scaphid nonunion advanced collapse (SNAC)
Osteoarthritis

Additionally, wrist fusion may be recommended for:

Severe wrist fractures
Significant wrist ligament injuries
Kienbock's disease
Preiser disease
Certain genetic disorders

The most prevalent form of wrist arthritis is scapholunate advanced collapse (SLAC), followed by scaphotrapezial-trapezoidal arthrosis, which is identifiable in approximately 40% of wrist radiographs.

Types of wrist fusion

There are several types of wrist fusion procedures, each designed to address specific conditions:

Radio-scaphoid-lunate fusion: Used for arthritis in the radiocarpal joint, typically after radius bone fractures .
Radio-lunate fusion: Often employed to treat rheumatoid arthritis and instability in certain parts of the wrist, including the midcarpal joint .
Scapho-Luno-capitate fusion: Utilized for midcarpal arthritis or wrist instability due to Kienbock's disease. This technique significantly limits movement but has a high fusion rate.
Scapho-trapezoid fusion: Used to treat arthritis in the scaphotrapeziotrapezoid (STT) joint and wrist instability caused by Kienbock's disease.
Four-corner fusion with scaphoid excision: Commonly used for advanced stages of severe arthritis, preserving some movement and grip strength.

These techniques vary in the specific bones they fuse and the amount of wrist mobility they preserve. The choice of procedure depends on the location and severity of the patient's condition, with the goal of providing pain relief while maintaining as much wrist function as possible .

The Wrist Fusion Procedure

Pre-operative preparation

Wrist fusion surgery, also known as wrist arthrodesis, requires thorough preparation. Before the procedure, patients undergo a comprehensive evaluation. This includes blood tests, electrocardiograms, and radiography to assess vital statistics and plan the surgery. A full radiographic assessment is crucial to evaluate the extent of arthritis and residual bone stock.

The surgical team plays a vital role in preparing patients for hand surgery. They review the patient's medical history, order diagnostic tests, and provide preoperative instructions. Patients are advised not to eat or drink anything after midnight prior to the surgery, as directed by the anesthesiologist.

It's important for patients to discuss their current medications with their doctor. They may need to discontinue certain medications, including aspirin and anti-inflammatory drugs, at least seven days before the surgery. Patients should arrive at the hospital at least two hours before the scheduled surgery time and arrange for a responsible adult to drive them home afterwards.

Surgical technique

The wrist fusion procedure is typically performed under general anaesthesia. An anesthetic team may administer a nerve block before the surgery to help with postoperative pain management . The patient is positioned supine on the operating table with the affected arm on a radiolucent arm table.

The surgeon begins by making an approximately 8 cm incision on the dorsal aspect of the wrist. They then remove the damaged cartilage to reduce wrist pain. The surgeon aligns the bones and connects them using screws and plates.

A Kirschner wire (K wire) is placed through the articular surface of the distal radius and another through the lunate. The wrist is positioned in 10 to 15 degrees of dorsiflexion and slight ulnar deviation to optimize handgrip strength. A surgical plate is then applied, typically a pre-contoured dynamic compression plate or a standard 3.5mm dynamic compression plate.

Post-operative care

After the surgery, the medical team applies a brace or cast to minimize movement. Patients receive medication to manage pain. The surgeon provides instructions on wound care before discharge.

Post-operative care is crucial for successful recovery. Patients are advised to keep the operated arm elevated to avoid swelling. Icing helps reduce swelling and should be done as suggested by the doctor. It's important to take prescribed medications as directed to manage pain and swelling.

Patients should be alert for signs of complications such as chills, shortness of breath, redness, swelling, or pus at the incision site. If these symptoms occur, immediate medical consultation is necessary. Typically, patients are not allowed to bear weight through the affected arm for 8 to 12 weeks following the surgery. Early finger mobilization is usually advised to maintain flexibility.

Recovery and Rehabilitation

The recovery process after wrist fusion surgery requires patience and careful adherence to medical advice. Patients are typically not allowed to bear weight through the affected arm for 8 to 12 weeks following the surgery. Early finger mobilization is advised to maintain flexibility and prevent stiffness.

Timeline for Recovery

Recovery from wrist fusion can take approximately 3 months. The initial two weeks are crucial, during which patients should avoid placing weight on their wrist and wear a brace. After this period, patients visit their doctor for a checkup, where stitches are removed and the wrist is examined to ensure proper healing.

Around the six-week mark, patients have another follow-up appointment with their surgeon. Throughout the recovery period, clinical follow-ups are essential to monitor wound healing, potential complications, and overall rehabilitation progress .

Physical therapy

A physiotherapy assessment is an important step in the recovery process. Physical therapy typically begins around two weeks post-surgery. These sessions help patients regain strength, flexibility, and function in their wrists and hands. Therapists guide patients through exercises designed to improve the range of motion in the fingers and strengthen the surrounding muscles.

Potential complications

While wrist fusion can provide significant relief, it's important to be aware of potential complications. Approximately one-third (33%) of patients undergoing total wrist fusion experience a postoperative complication, with 19% requiring a reoperation.

One potential complication is non-union, where the bones fail to fuse properly. In such cases, a second wrist fusion procedure may be necessary. Additionally, hardware issues, such as breakage or irritation, might require further surgical intervention.

It's worth noting that smokers have an increased risk of soft tissue complications after total wrist fusion. Therefore, patients are often advised to quit smoking before and after the surgery to improve their chances of successful recovery.

Conclusion

Wrist fusion surgery has a significant impact on patients suffering from severe wrist pain or instability. This procedure, which joins the carpal bones and sometimes the radius, aims to eliminate movement in the wrist joint to provide relief. By exploring the surgical process, recovery, and rehabilitation, we've shed light on what patients can expect when undergoing this treatment. The various types of wrist fusion, each designed to address specific conditions, highlight the versatility of this surgical approach to improve patients' quality of life.

While wrist fusion can be a game-changer for many, it's crucial to understand the recovery process and potential risks involved. The journey to recovery takes time and dedication, with patients typically needing several months to regain strength and function. Physical therapy plays a key role in this process, helping patients adapt to their new wrist mobility. As with any major surgery, complications can arise, making it essential for patients to stay in close contact with their healthcare team throughout the recovery period. In the end, for many patients, the benefits of reduced pain and increased grip strength make wrist fusion a worthwhile option to consider.

FAQs

Q. How much time is required for recovery after a wrist fusion surgery?
A. Recovery from a wrist fusion surgery generally spans at least three months for the bones to heal, with continuous improvement observed over the first six months. Most patients adjust well to the reduced motion within the first year.

Q. Are there limitations in wrist movement post-wrist fusion surgery?
A. Post-surgery, bending the wrist will not be possible. Wrist fusion involves a compromise where you sacrifice some range of motion in exchange for a strong and pain-free wrist.

Q. What materials are used for the implants in wrist fusion surgery?
A. For wrist fusion, straight plates are typically utilized for fixation when standard and short-bend plates are unsuitable due to anatomical variations. These plates can be shaped to fit the specific contours of a patient's wrist. The materials used for these implants include 316L stainless steel and commercially pure titanium, which are both known for their implant quality.

Q. What is the success rate of wrist fusion surgeries?
A. The success rate of wrist fusion surgeries is quite high, with an average fusion rate of 91% reported in multiple studies. Additionally, patient-reported outcomes indicate low pain levels and relatively moderate disability in arm, shoulder, and hand functions.