Reverse shoulder replacement is a specialized surgical procedure designed to restore function and relieve pain, primarily for individuals with severe shoulder arthritis and irreparable rotator cuff damage. Unlike a traditional replacement, the ball and socket components are reversed: the socket is placed on the upper arm bone, and the ball is attached to the shoulder blade. This altered configuration allows the large deltoid muscle to take over the work of the damaged rotator cuff, improving the ability to raise the arm. Although the procedure offers significant pain relief and improved movement, strict adherence to short-term and permanent restrictions is necessary to protect the implant and ensure long-term success.
Immediate Post-Surgical Restrictions
The initial recovery phase, typically the first six to twelve weeks, involves limitations necessary for the soft tissues and implant to heal securely. Patients must wear an arm sling, often an abduction sling, for a period determined by the surgeon, commonly four to six weeks. The sling protects the shoulder, especially if a tendon, such as the subscapularis, was cut and repaired during the operation.
During this time, patients are prohibited from performing active range of motion (AROM) exercises, meaning they cannot use their own muscles to lift or move the operated arm away from the body. Lifting is restricted to extremely light objects, generally limiting the weight to one or two pounds. This prevents undue stress on the surgical site and the newly positioned components.
Other restrictions during this period include avoiding supporting body weight with the operated arm, such as pushing up from a chair or bed. Driving is also prohibited, particularly if the surgery was performed on the dominant arm, as the patient cannot safely control the steering wheel or react quickly. Patients must avoid movements that strain the joint, specifically combinations of adduction, extension, and internal rotation, to prevent instability.
Long-Term Movement Limitations
After the initial healing and rehabilitation phases, the patient transitions to permanent restrictions designed to protect the artificial joint from mechanical failure and loosening. The most significant long-term limitation is a weight restriction, with most surgeons advising against lifting more than 20 to 25 pounds with the operative arm. Heavy lifting creates high forces at the joint’s socket (glenoid), which can lead to premature implant loosening and wear.
Patients must permanently avoid high-impact, forceful, or repetitive overhead activities. Contact sports, such as football or aggressive basketball, are discouraged due to the risk of joint dislocation or component damage. Activities involving repetitive pushing, pulling, or sudden jerking movements should also be avoided.
Specific movements involving internal rotation and extreme force are also permanently limited. Reaching directly behind the back, such as tucking in a shirt or fastening a bra, often remains challenging or impossible due to the altered biomechanics of the reverse prosthesis. While low-impact activities like walking, cycling, and gentle swimming are encouraged, any activity that puts excessive stress on the new joint must be modified or eliminated.
Activities Requiring Modification
Many daily activities require a permanent change in technique or approach to protect the new shoulder joint. Dressing is modified by putting the operated arm into the sleeve first and taking it out last, often favoring loose-fitting or button-down shirts. This technique avoids excessive stretching or forceful movements, particularly when reaching behind the back.
Hygiene tasks also require adjustments, as reaching across the body to wash the opposite armpit or reaching for toileting may be restricted. Patients may need to utilize assistive devices, such as long-handled sponges for bathing, or employ the non-operated arm for certain tasks. These modifications prevent the shoulder from being forced into positions that could cause instability or strain the soft tissues.
Sleeping positions must also be adapted, and patients are advised to avoid sleeping directly on the operated side to prevent compression or pressure on the joint. Reaching for items on high shelves should be done with the non-operated arm or by using a stable step stool or reacher tool to avoid overhead strain. The goal is to perform daily functions by keeping the elbow close to the body while respecting the permanent rotational and weight-bearing limitations.
The Rationale Behind the Restrictions
The necessity for these restrictions stems from the fundamental change in the shoulder’s biomechanics inherent in the reverse design. The procedure moves the center of rotation medially and distally, which increases the lever arm for the deltoid muscle, making it more effective at lifting the arm. This configuration also places different forces on the components and alters the joint’s stability profile.
The long-term weight limits are necessary because excessive load creates high shear forces at the glenoid baseplate, the component attached to the shoulder blade. This sustained stress can lead to the loosening of the implant from the bone, a complication that may require revision surgery. The altered geometry also makes the joint more susceptible to dislocation when the arm is moved into specific positions, such as combined internal rotation and adduction.
The permanent limitations safeguard the longevity of the prosthetic joint, which is a mechanical device subject to wear and tear. Respecting the restrictions on high-impact and heavy-lifting activities significantly reduces the risk of polyethylene liner wear and implant failure. Compliance with these guidelines ensures the replacement lasts its expected lifespan, typically 10 to 15 years.