Have you ever heard of something called an antibiotic spacer (or something like that) for a shoulder infection? My father had a shoulder replacement about six months ago that’s been nothing but trouble. Now he’s got an infection and this is the treatment they are recommending. We’re 2000 miles away and can’t really help but we offered to research it on the Internet. What can you tell us about the procedure?

Shoulder replacements (called shoulder arthroplasty) are not done as often as hip and knee replacements. But more and more older adults are taking advantage of this available surgery. As with any joint replacement, complications and problems can arise. One of those problems is deep joint infection.

The ideal treatment for this problem has not yet been determined. Previous studies have shown that deep joint infections do not always respond well to debridement and irrigation procedures (cutting out the infection and cleansing the joint with fluid). Just cutting out the infected implant isn’t a very good option either because that leaves the patient with loss of hip motion and difficulty weight-bearing.

That’s why this idea of a spacer was introduced. The implant is referred to as a Prosthesis of Antibiotic-Loaded Acrylic Cement or PROSTALAC. It is used to replace the first (infected) prosthesis. Prosthesis is another word for the implant used to replace the joint.

The PROSTALAC is made by the surgeon for each individual patient. It is shaped just like the stem and round head at the top of the natural femur (thigh bone). There are different ways to create the mold for the PROSTALAC implant.

In most cases, the surgeon uses a tubular-shaped plate or flat dynamic compression plate and the formed the PROSTALAC implant around the tube or plate. Either of these approaches gives the spacer more support. In a smaller number of patients, no internal support beam or scaffold is used.

The infected implant is removed and the PROSTALAC implant put in place instead. In some patients, this device is considered a spacer — in other words, it holds the place of the femoral side of the joint until the infection is cleared up and a new prosthesis can replace it. Other patients elect to keep the PROSTALAC spacer as their permanent implant. Keeping the PROSTALAC spacer as the permanent implant avoids another (revision) surgery.

Surgeons who use this treatment approach to deep joint infection of the shoulder suggest the use of a spacer like the PROSTALAC can be very helpful. The implant can stabilize the joint, provide pain relief, and restore some shoulder function. But you should know that it’s not without its problems. For example, complications such as a second (recurrent) infection, dislocation, or fracture of the PROSTALAC have been reported.