WHEN IS A SHOULDER REPLACEMENT NEEDED?
Shoulder joint degeneration with moderate to severe osteoarthritis can progress over time leading to pain and limited range of motion. These factors reduce the inability to use your shoulder to perform daily and work tasks. Your ability to participate in recreational upper extremity tasks may also be impacted. If you have had a complex shoulder fracture, this may also lead to an orthopedic surgeon recommending a total shoulder arthroplasty (replacement).
UNDERSTANDING THE SHOULDER JOINT
The shoulder joint is formed by the head of the humerus (the upper arm bone) as the “ball” and the scapula (shoulder blade) which forms the “socket”. This healthy ball and socket style joint allows for very good motion in many directions. When severe arthritis or a complex fracture occurs at this joint, the joint surfaces can be very rough. Movement on these rough edges can lead to pain and loss of function. The total shoulder arthroplasty (TSA) removes the arthritic “ball and socket” and replaces them with artificial parts.
A total shoulder arthroplasty is often described to patients as a last resort procedure to primarily relieve their pain. Patients typically get about 120-130 degrees of overhead motion. In an uninjured shoulder, overhead motion can be up to 180 degrees. To put this in perspective, 90 degrees means the elbow raises to shoulder height as a reference. The patient can become moderately strong with good function especially from the shoulder height and below. Overhead very light lifting and reaching is also usually achievable.
Illustration of shoulder range of movement.
HOW IS THE DECISION ON TYPE OF REPLACEMENT DETERMINED?
The recommendation to get a traditional or a reverse TSA is done by the orthopedic surgeon. The type recommended depends on a couple factors. Health of the bone in the joint and the intact muscles and tendons available drive the decision.
A traditional TSA is performed when the patient has an intact and healthy rotator cuff complex. The rotator cuff is made up of 4 muscles and their corresponding tendons. This group of muscles is involved in generating most shoulder motions.. The head or “ball” of the humerus is removed and replaced by a prosthetic (metal) ball which is attached to a stem that extends into the center of the humerus. The scapula’s socket is fitted with a plastic socket. The mechanics of the shoulder will continue to be mainly controlled by the rotator cuff muscles, the deltoid muscle and some other muscles.
If the rotator cuff is significantly damaged, certain complex fractures are present or when a traditional TSA has not resulted in the desired outcome, the orthopedic surgeon may recommend getting a reverse TSA. This reversed procedure involves placing the metal ball where the scapula’s socket is and placing the plastic lined artificial socket at the upper end of the humerus. Thus, the “ball and socket” artificial components positions are reversed. The primary muscle after this procedure to control the shoulder joint motions is the deltoid with most or all of the rotator cuff no longer being attached.
WHAT DOES PHYSICAL THERAPY DO AFTER A TOTAL SHOULDER REPLACEMENT
After either type of TSA, physical therapy is needed and is guided by the procedure performed and the surgeon’s post-operative orders. These orders dictate the amount and direction of motions permitted at different time frames. The protocols also determine when strengthening can start. This guided progression considers soft tissue and bone / prosthetic component healing times. Certain restrictions also help to prevent shoulder joint dislocation. Every surgeon has their own specific rehab guidelines.
In general, the physical therapy starts around 2-3 weeks after the surgery. A sling is continued for 4-6 weeks except for during physical therapy, home exercises and showering. Patients continue to sleep in the sling for 6 weeks. Passive (done by the physical therapist with the patient relaxed) range of motion is allowed into forward flexion/ over shoulder height elevation and to the elbow and wrist of the involved arm..
With the elbow bent to 90 degrees (L -shaped angle) the different surgeries allow varying amounts of internal (towards the stomach) and external rotation (away from the stomach). These limitations are to allow soft tissue healing and to avoid dislocation of the replaced joint. Gentle patient range of motion exercises are taught and performed at home that follow the same protective guidelines monitored in the clinic.
PHYSICAL THERAPY PROGRESSION
At the 4-6 week post operative time frame, the sling starts to be used less with the goal of discontinuing it at 6 weeks. More range of motion is permitted and the patient is allowed to raise the arm without assistance but still within the surgeon’s guidelines. Light strengthening is started usually at 6 weeks. More range of motion and strengthening are allowed and expected at the 8-10 week period.
By 12 weeks, most motions are allowed and the patient should be stronger from the strengthening exercises and from being permitted to use the arm for light tasks. Physical therapy after 12 weeks continues to focus on strengthening including more progression for over shoulder height exercises. A gradual return to daily and recreational activities is based upon each patient’s progression and the surgeon’s clearance.
WHAT PATIENTS NEED TO UNDERSTAND ABOUT EXPECTATIONS FOR TOTAL SHOULDER REPLACEMENT
When opting for this surgery, the patient must understand that the surgery is completed primarily for pain relief. The amount of motion, strength and function is expected to be limited long-term compared to when they had a healthy shoulder. However, patients are expected to and typically do achieve a much less painful and improved functional level of the arm compared to weeks prior to this type of surgery being performed.
OPTIMAL PHYSICAL THERAPY AND SPORTS PERFORMANCE HAS EXPERIENCE IN PROVIDING THIS TYPE OF CARE
The therapists at Optimal Physical Therapy and Sports Performance have extensive experience with patients who undergo this procedure and have produced significant functional recovery for these patients. It is important that you have the right therapist on your team as you recover. We would be happy to be the therapy team to assist you. Please contact us at 724-779-1300 if you have any further questions or would like to set up your appointment.
