Minimally Invasive Shoulder Joint Replacement

Shoulder Anatomy

The shoulder is a ball and socket joint that allows various arm movements. The head of the upper arm bone (humerus) articulates with the glenoid cavity of the shoulder bone (scapula). The two articulating surfaces of the bones are covered with cartilage which prevents friction between the moving bones. A rotator cuff is a group of four tendons that join the head of the humerus to the deeper muscles and provides stability and mobility to the shoulder joint. 

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 through a minimally invasive approach. The incision of a minimally invasive shoulder joint replacement is about 5 cm compared to 17 cm with the traditional 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 conditions such as arthritis, avascular necrosis, and humeral head fractures, then shoulder joint replacement is considered as a treatment option.

The decision to perform shoulder replacement via the traditional approach or the minimally invasive approach depends on the pathology. Exposure of the glenoid is often difficult even when the incision is long as in the traditional approach. Therefore, if the pathology is such that more exposure to the joint is required for the surgical treatment then a traditional approach is preferred.

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 tiny multiple fractures 

Diagnosis

To determine the pathology, your surgeon orders an X-ray of the shoulder in the anteroposterior and axillary view. The axillary X-ray is especially important to check the condition of the glenoid. In case the condition is not very clear, 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 are 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. This may be press-fit, relying on the bone to grow into it or cemented, depending on several factors such as bone quality and your surgeon’s preference.
  • If the glenoid also needs to be replaced, your surgeon then proceeds to the preparation of the glenoid component.
  • The glenoid is sized for the appropriate implant.
  • Next, the glenoid is prepared to take the artificial component by drilling holes in the glenoid 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 closed with absorbable sutures.
  • An X-ray is taken to verify the correct fit (size and position) of the implant.

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 when compared to the open technique.

Risks and Complications of Minimally Invasive Shoulder Joint Replacement

Some of the 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.

ARTHROSCOPIC ROTATOR CUFF REPAIR

Rotator cuff is the group of tendons in the shoulder joint providing support and enabling wider range of motion. Major injury to these tendons may result in tear of these tendons and the condition is called as rotator cuff tear. It is one of the most common causes of shoulder pain in middle-aged adults and older individuals. It may occur with repeated use of arm for overhead activities, while playing sports or during motor accidents. Rotator cuff tear causes severe pain, weakness of the arm, and crackling sensation on moving the shoulder in certain positions. There may be stiffness, swelling, loss of movement, and tenderness in the front of the shoulder.
Rotator cuff tear is best viewed on magnetic resonance imaging. Symptomatic relief may be obtained with conservative treatments – rest, shoulder sling, pain medications, steroidal injections and certain exercises. However, surgery is required to fix the tendon back to the shoulder bone.

How is the procedure performed?

Surgery to repair the rotator cuff has traditionally been done through a large shoulder incision, about 6-10cm long, and the muscle over the rotator cuff was separated. Newer, advanced surgical techniques have been developed to minimize pain and recovery time. Arthroscopic rotator cuff repair is a minimally invasive surgery performed through tiny incisions, about 1 cm each, with an arthroscope.
The arthroscope is a small fiber-optic viewing instrument made up of a tiny lens, light source and video camera. The surgical instruments used in arthroscopic surgery are very small (only 3 or 4 mm in diameter) but appear much larger when viewed through an arthroscope.
The television camera attached to the arthroscope displays the image of the joint on a television screen, allowing the surgeon to look throughout the shoulder-at cartilage, ligaments, and the rotator cuff. The surgeon can determine the amount or type of injury, and then repair or correct the problem.

What are the benefits of arthroscopic surgery?

The benefits of arthroscopy compared to the alternative open shoulder surgery, include:
• Smaller incisions
• Minimal soft tissue trauma
• Less pain
• Faster healing time
• Lower infection rate
• Less scarring
• Earlier mobilization
Usually performed as outpatient day surgery

Shoulder Stabilization

Disease Overview

Shoulder instability is a chronic condition that causes the frequent dislocation of the shoulder joint. A dislocation occurs when the end of the humerus (the ball portion) partially or completely dislocates from the glenoid (the socket portion) of the shoulder. A partial dislocation is referred to as a subluxation while a complete separation is referred to as a dislocation. The repeated dislocation of the humerus out of its socket is called chronic shoulder instability. A tear in the labrum or rotator cuff and a ligament tear in the front of the shoulder (a Bankart lesion) may lead to repeated shoulder dislocations.

Indications for Shoulder Stabilization

When conservative treatment options such as medications, rest and ice application fail to relieve shoulder instability, your surgeon may recommend shoulder stabilization surgery. 

Shoulder Stabilization Surgery Procedure

Shoulder stabilization surgery is performed to improve stability and function to the shoulder joint and prevent recurrent dislocations. It can be performed arthroscopically, depending on your particular condition, with much smaller incisions. Arthroscopic stabilization is a surgical procedure to treat chronic instability of the shoulder joint. 

Arthroscopy is a minimally invasive surgery and is performed through two tiny incisions (portals), about half-inch in length, made around the joint area. Through one of the incisions, an arthroscope (small fiber-optic viewing instrument) is passed. A television camera attached to the arthroscope displays the images of the inside of the joint on the television monitor, which allows your surgeon to view the cartilage, ligaments and the rotator cuff while performing the procedure. A sterile saline solution is pumped into the joint, which expands it and provides a clearer view. Bone spurs, defects or tissue tears will be identified.

Your surgeon makes use of tiny surgical instruments that are passed through the other incisions to treat the condition. Any tear in the rotator cuff will be sutured or stapled. The sutures will be held in place with the help of a small anchor that is drilled into the upper part of the humerus. Further, a thermal shrinkage device may be used in order to make the ligaments tight and prevent instability.

Postoperative Care for Shoulder Stabilization

Following the procedure, your surgeon may advise the use of a continuous passive motion machine to prevent stiffness and improve range of motion of the shoulder joint. Pain medications will be prescribed to keep you comfortable. A shoulder sling can be worn for 4-6 weeks to immobilize and facilitate healing. A postoperative rehabilitation program including strengthening exercises will be advised for 6-9 months. You will be able to participate in sports in about 18 to 36 weeks after the surgery.

Advantages of Shoulder Stabilization

The major benefits of arthroscopic stabilization as compared to the open repair are that it gives a chance to identify and treat coexisting diseases, lesser pain and complications, combined with a shorter hospital stay.

Risks and Complications of Shoulder Stabilization

As with any surgical procedure, there may be certain risks and complications involved and include infection of the surgical wound, postoperative stiffness, risk of arthritis, muscle weakness and injury to the nerves and blood vessels.