Total Shoulder Replacement
January 1, 2021
Dr. Shaw provides the full scope of shoulder care and surgery, from strains and rotator cuff tear to shoulder replacement. Patients with arthritis are great candidates for a shoulder replacement. The decision to have a shoulder replacement is based on the shoulder’s disability and the level of pain the patient experiences over time. X-rays of the shoulder that demonstrate narrowing of the joint space and bone spur formation can be used to determine if a shoulder replacement is the best option.
Shoulder replacement is done as an outpatient surgery in most cases. A multimodal pain medication plan is used to minimize the amount of narcotics necessary post operatively. A regional block and a general anesthetic is used. An incision is made in the front of the shoulder and almost no muscle is cut except for one tendon in the front of the shoulder called the subscapularis. The subscapularis is then repaired at the end of surgery.
The arthritic bone surfaces are scraped or removed and metal and plastic are placed so that motion at the shoulder joint occurs over the artificial resurfacing. Pain relief is excellent with shoulder replacement and many times function will return allowing patients to enjoy many activities requiring the shoulder and arm. Many patients report having excellent function, and implant survival is found for 15-20 years. If the implant were to loosen or wear out, it can be revised with a second surgery at a later date.
There are a few types of shoulder replacement available. One option is resurfacing of the humeral head when the arthritis is not as severe and the cartilage on the glenoid, the socket side of the joint, is still maintained. This option is not as commonly performed because most patients have arthritis that is too severe to allow the resurfacing to work.
The “standard” shoulder is known as the anatomic shoulder replacement and performed on most patients. This resurfaces both sides of the joint, the glenoid, and the humeral head. A rotator cuff must be well-functioning for this shoulder replacement to work correctly. The humeral head component can be fixed into the humerus with a stem or with the “stemless” option which is minimally invasive. The below pictures demonstrate the two options. Dr. Shaw performs most of his cases with the stemless option.
The third type of shoulder replacement is what is known as the “reverse” shoulder replacement. This is done for patients who have arthritis and a rotator cuff tear. Typically, an x-ray is all that is needed to determine if the patient has this combination of rotator cuff tear and shoulder arthritis. Sometimes an MRI may be necessary to confirm a rotator cuff tear. In the reverse shoulder surgery, the hemisphere is placed on the glenoid and the stem and “socket” are placed on the humerus. This in essence reverses the orientation of the normal anatomic shoulder geometry. This provides the shoulder pain relief and the ability to lift the arm because of the mechanics of the reverse shoulder. In all cases the approach to the shoulder surgically is the same with a 4-5-inch incision made over the front of the shoulder.
Dr. Shaw uses preoperative CT scan in many cases to assist with preoperative planning of the shoulder surgery. The CT scan provides a way for the detailed anatomy to be assessed using a 3D software program to determine optimum implant position before the surgery is performed. In cases where there is significant wear of the bone, special augmented implants can be planned so that the best stability and function of the shoulder is provided with the shoulder replacement. In essence the preoperative planning with the CT reconstruction of the shoulder allows Dr. Shaw to plan the optimal shoulder replacement for his patient. A drill guide will be custom made for the patient’s anatomy to place the glenoid in the best position.
Please see the Zimmer Biomet website link below to read more about the implants Dr. Shaw uses and other general information about shoulder replacement.