A partial shoulder replacement is a surgical procedure designed to alleviate pain and restore function in a shoulder joint damaged by injury or disease. It is a specialized option for individuals experiencing persistent shoulder discomfort and limited movement that has not responded to other forms of treatment.
Defining Partial Shoulder Replacement
A partial shoulder replacement, medically termed hemiarthroplasty, involves replacing only one part of the shoulder joint. The damaged head of the humerus, the “ball” portion of the shoulder’s ball-and-socket joint, is removed and replaced with a prosthetic metal implant. The glenoid, the “socket” part of the shoulder blade, is left intact. This contrasts with a total shoulder replacement, where both the humeral head and glenoid socket are replaced.
The prosthetic implant typically consists of a metal ball attached to a stem inserted into the humerus. Another type, resurfacing hemiarthroplasty, involves placing a cap-like prosthesis over the humeral head without a stem, preserving more bone. The decision between partial and total replacement depends on the extent of joint damage.
When a Partial Replacement is Considered
A partial shoulder replacement is considered when damage is primarily confined to the humeral head, and the glenoid socket remains healthy. This option is recommended for conditions such as severe fractures of the upper arm bone, avascular necrosis (AVN) of the shoulder, or specific forms of osteoarthritis affecting the humeral head. Surgeons often prefer partial replacement for younger, more active individuals to preserve natural joint structure. This approach is pursued when non-surgical treatments have not provided adequate relief.
The Surgical Journey
The process of undergoing a partial shoulder replacement begins with thorough pre-operative evaluations. These assessments include medical examinations and imaging tests. On the day of the procedure, either general anesthesia, which induces a sleep-like state, or regional anesthesia, which numbs the shoulder and arm, is typically administered.
The surgeon then makes an incision over the affected shoulder, often along the front or top, to access the joint. Muscles are carefully separated to expose the shoulder joint, allowing clear visibility of the humeral head and glenoid. The damaged portion of the humeral head is precisely removed, and the bone is prepared for the prosthetic implant.
A metal prosthetic component, either with a stem or as a cap, is then securely inserted into the humerus. If necessary, the glenoid socket may be smoothed or reshaped to ensure proper articulation with the new humeral head. Once the implant is in place and stability is confirmed, the muscles and tissues are carefully reapproximated, and the incision is closed.
Post-Surgery Expectations
Following a partial shoulder replacement, patients typically experience some pain, which is managed with medication. The hospital stay is often brief, with some individuals even going home the same day. A sling is usually worn for several weeks, often between two to six weeks, to protect the healing shoulder and limit movement.
Physical therapy is a fundamental part of recovery and usually begins soon after surgery, sometimes within a day or two. Initial exercises focus on gentle, passive range of motion to prevent stiffness, gradually progressing to more active movements and strengthening exercises.
Most patients see significant improvements in pain relief and range of motion within a few weeks to months. Full recovery and return to normal activities can take several months, with continued improvement in strength and function possible for up to two years. While individual recovery varies, many patients achieve substantial pain reduction and improved mobility, allowing them to resume many daily activities and even some recreational sports.