Total Shoulder Replacement
What is it?
A total shoulder arthroplasty is a proven treatment option for arthritis involving the ball and socket joint of the the shoulder. It involves removing the arthritic surfaces of the shoulder joint, releasing any soft tissue contractures, and resurfacing the joint with a metal ball and a highly engineered plastic socket. This is intended to relieve the pain associated with arthritis and improve the motion and function of the shoulder. Shoulder replacements have been performed in their modern form since the 1960s and the shoulder is the third most commonly replaced joint behind hips and knees.
How is it performed?
A shoulder replacement is performed through an incision on the front of your shoulder. We are able to spread most of the muscles out of the way to expose the shoulder joint.
Only one tendon, a rotator cuff tendon (subscapularis), needs to be detached in order to access the joint. It is repaired at the end of the surgery and is the reason for many of the post-operative restrictions on the shoulder. All bone spurs are taken out and the arthritic surfaces are removed. A new metal ball is placed that is typically anchored to your bone with a stem that sits inside the bone canal. A plastic socket is cemented securely into place. An x-ray of a shoulder replacement is demonstrated here.
What are the Risks?
Major medical complications are rare during the peri-operative period of a total shoulder. We screen patients carefully to ensure that they are at minimal risk for any of these complications. Aside from routine surgical and anesthetic risks (bleeding, infection, anesthesia side effects...), below are some of the most common risks associated with a shoulder replacement:
- Subscapularis failure: This is the one tendon that is detached in order to access the joint. It must be repaired robustly at the end of the case. It must heal in place in order for shoulder function to be optimal.
- Shoulder instability: Occationally shoulders can be unstable after replacement. The soft tissues are carefully balanced at the time of surgery to help prevent this but some patients, especially ones who had evidence of instability prior to the surgery, may be at increased risk for this complication.
- Nerve Injury: In particular, one nerve (the axillary nerve), which controls your deltoid muscle, is near the operative field. It must be identified and protected in every case. Other nerves can also be at risk too but are further from the operative field. Injuries are not common, but when they do occur, it is usually related to stretching of the nerve, the majority of which recover with time.
- Implant wear and loosening: The implant can wear over time, just like the tread on your car tires. This can potentially lead to loosening of the components, particularly the socket. This takes 15+ years to develop in most people although many patients still have a well functioning prosthesis for > 20 years.
How do I Know if I Have Shoulder Arthritis?
Patients with shoulder arthritis have pain localized to the shoulder region and loss of motion. Loss of motion can occur in all planes of motion but particularly affects external rotation of the shoulder (rotating your shoulder out to the side). Some patient may notice painful popping and cracking within the shoulder. Patients may experience a constant dull ache within the shoulder which is worsened with shoulder motion and activity.
X-rays and examination are typically all that is needed to diagnose shoulder arthritis. These will demonstrate loss of the joint space in the shoulder and bone spur formation around the periphery of the joint as shown in these x-rays. Occasionally a CT scan may be needed if there is excessive wearing of the bone in the shoulder.
What are the Expected Results
In general, total shoulder arthroplasty is excellent at relieving the pain associated with shoulder arthritis and improving the motion of the shoulder. Many patients who work hard at therapy have near normal shoulder function. Many patients are able to return to activities such as gardening, fishing, tennis, golfing, and swimming. The only activities that are discouraged are heavy manual labor, heavy repetitive lifting, and repetitive high impact activities. The reasoning is that these activities can potentially lead to early loosening of the socket. Patients who desire to continue to perform some of these activities may consider a replacement without a socket (hemiarthroplasty or a ream and run), but, only if they are highly motivated to work through the rigorous post-operative therapy and prolonged recovery. Otherwise a routine total shoulder arthroplasty is one of the most predictable treatments for your arthritis.
How Long is the Recovery?
Patients typically stay in the hospital 1-2 nights. Most patients are off all pain medications by their first post-operative appointment. The early recovery (<6 weeks) is focused on regaining shoulder motion and protecting the subscapularis repair. The middle of the recovery (6-12 weeks) is focused on regaining shoulder strength and maintaining motion. The end of the recovery (>12 weeks) is focused on functional strengthening to get you back to the activities you desire. After 12 weeks there are no specific restrictions on the shoulder but it can take >6-9 months to achieve a full recovery
Who is Not a Good Candidate for a Total Shoulder?
While a total shoulder arthroplasty general provide predictably good results following surgery, there are some patients in which the results of a total shoulder are less predictable. These include the following types of patients:
- Patients with large rotator cuff tears
- Patients on chronic pain medications
- Patients with multiple prior surgeries on their shoulder
- Patients with neurologic injury involving the shoulder
- Patients in poor general health and physical conditioning
While having any of these conditions does not mean that a total shoulder arthroplasty cannot be performed, it could mean that alternative methods of treatment may be safer and more.