What is Minimally Invasive Shoulder Joint Replacement?
Shoulder joint replacement is a surgical procedure that replaces damaged bone surfaces with artificial humeral and glenoid components to relieve pain and improve functional ability in the shoulder joint.
It can be performed by a traditional open approach or a minimally invasive approach. A minimally invasive shoulder joint replacement incision is about 5 cm compared to 17 cm with the conventional approach.
Indications for Minimally Invasive Shoulder Joint Replacement
When conservative measures such as medications, injections, physical therapy, and activity changes do not help relieve pain from arthritis, avascular necrosis, and humeral head fractures, shoulder joint replacement is considered a treatment option.
The decision to perform shoulder replacement via the traditional or minimally invasive approaches depends on the pathology. Exposure of the glenoid is often problematic even when the incision is long, as in the conventional approach. Therefore, a traditional approach is preferred if the pathology is such that more exposure to the joint is required for the surgical treatment.
The minimally invasive approach is generally preferred when the problem can be rectified by replacement of only the humeral head, such as with the following conditions:
- Shoulder arthritis with not much damage to the glenoid and with only small bone spurs
- Four-part humerus fractures with intact rotator cuff
- Avascular necrosis of the humerus, resulting in multiple tiny fractures
To determine the pathology, your surgeon orders an X-ray of the shoulder in the anteroposterior and axillary view. The axillary X-ray is essential to check the condition of the glenoid. If the condition is unclear, your surgeon orders a CT scan of the shoulder to provide more detailed cross-sectional images of the bone and soft tissue of the shoulder, including the glenoid.
Minimally Invasive Shoulder Joint Replacement Procedure
- The surgery is performed under sterile conditions in the operating room under regional or general anesthesia.
- You will lie in a beach chair position with the operated arm held by an arm positioner.
- A 5-cm incision is made over the shoulder joint.
- The muscle overlying the shoulder bones is cut just enough to expose the head of the humerus.
- The humeral head is dislocated and released from the capsule.
- The arthritic or damaged humeral head is cut at the neck and removed.
- The humeral component is matched in diameter and thickness to the natural humeral head.
- A bone tunnel is made in the humerus to take the humeral stem.
- The humeral stem is then inserted into the humerus. Depending on factors such as bone quality and your surgeon’s preference, this may be press-fit or cement, relying on the bone to grow into it.
- If the glenoid also needs to be replaced, your surgeon proceeds to prepare the glenoid component.
- The glenoid is sized for the appropriate implant.
- Next, the glenoid is prepared to take the artificial component by drilling holes to fix the plastic glenoid component.
- Bone cement is placed in the holes, and the glenoid implant is inserted.
- Once the glenoid is replaced with the plastic component, your surgeon works on the humeral component.
- The correct-sized metallic humeral component is then fixed to the humeral stem.
- The soft tissue covering the joint is sutured back together, and the incision is closed with absorbable sutures.
- An X-ray is taken to verify the implant’s correct fit (size and position).
Postoperative Care for Minimally Invasive Shoulder Joint Replacement
After the surgery, your arm will be placed in a sling, which you will wear for 2-4 weeks while your shoulder heals. Pain medications and antibiotics are administered to keep you comfortable and prevent infection.
The rehabilitation program includes physical therapy, which is started soon after the surgery and is very important to strengthen and provide mobility to the shoulder. Follow your therapist’s instructions for home exercises to achieve the best outcome.
It is critical to follow the postoperative instructions given to you by your surgical team. The postoperative instructions include the following:
- Rest your shoulder. No lifting, pushing, or pulling for the first few weeks.
- Perform home exercises as advised by your therapist.
- Do not overuse your shoulder while healing, as it may result in severe limitations in motion later.
- Do not drive a car for the first few weeks after the surgery.
- Avoid getting the incision wet until fully healed.
Advantages of Minimally Invasive Shoulder Joint Replacement
The benefits of minimally invasive surgery include less damage to the soft tissues and underlying muscles, enabling a faster recovery with less pain and a smaller scar. Blood loss during the surgery is also less, and complications after the surgery are fewer compared to the open technique.
Risks and Complications of Minimally Invasive Shoulder Joint Replacement
Some possible risks and complications of minimally invasive shoulder joint replacement include infection, nerve injury, and prosthesis problems. Most of these can be treated successfully; however, prosthesis problems such as excessive wear, loosening of components, or dislocation may require additional revision surgery.