I'm having trouble finding a surgeon in my area to consider doing an elbow replacement on me. If I needed a new knee or hip: no problem! But no one around here does them. Are they really that tricky?
As with any joint replacement procedure, there can be complications. In fact, the risk of problems following elbow replacement is far greater than with a hip or knee replacement. The risk of complications and the surgical expertise required for elbow replacements may help explain why not all surgeons perform this procedure.
The six most recognized post-operative problems associated with elbow replacement include loosening of the implant, fracture of the bone around the implant, implant failure, infection causing loosening of the implant, weakness of the triceps muscle, and nerve palsy. Here's a quick look at each one starting with the most common cause of implant failure: loosening.
Loosening of the implant can occur even when there hasn't been an infection or fracture of the bone around the implant. It's a complicated problem. Normal elbow function requires slight side-to-side motion with a little rotation even as the joint is bending and straightening.
Reproducing all of that with a metal implant is a challenge. The implant has to be placed in the right position with the correct angle and just the right amount of soft tissue tension. The alignment of the implant stem (placed down into the bone to anchor the implant) is another key feature that can affect elbow function.
The capsule and ligaments around the elbow along with the muscles and their tendon attachments contribute to elbow stability and function. Keeping all of this balanced after removing the diseased elbow and putting an implant in place requires considerable surgical technical expertise.
There are different types of implants that seem to work better with the soft tissues than others. Research efforts are being directed toward improving the implant design in order to reduce the number of complications from loosening.
Then there's periprosthetic fractures another possible complication in up to 29 per cent of cases. Periprosthetic fracture refers to cracks in the bone around the implant or fracture lines down the shaft of the bone.
These can develop as a result of trauma, poor implant alignment, or as a direct consequence of the patient's activities. Patients are given guidelines for what they can and can't do until full healing takes place but they don't always follow those guidelines. Doing too much too soon can be very detrimental.
Implant failure refers to some aspect of the implant wearing out causing squeaking, pain, and poor elbow movement. Increased stress on the implant from poor alignment can cause what's called fatigue fracture. The implant itself breaks. Elbow deformity may be occur as a result of any of these problems.
Infection after total elbow arthroplasty develops in a fair number of patients. Studies report a three to eight per cent rate of infection. Detected and treated early with antibiotics, this complication is more manageable than some of the other problems that require additional surgery. In extreme cases, surgery to remove and replace the implant may be needed.
The patient who can't reach overhead or push a door open may have weakness of the triceps muscle referred to as triceps insufficiency. The triceps muscle located along the back of the upper arm helps extend (straighten) the elbow.
In order to get to the joint, the triceps muscle may be cut and moved out of the way. Of course, it is reattached but cutting it at all can lead to problems. Newer surgical techniques have been developed to spare this muscle and prevent postoperative weakness (and the need for another surgery to fix the problem).
One last problem to consider: nerve palsy. There are two important nerves to the hand that are located on either side of the elbow: the radial and ulnar nerves. The ulnar nerve is at greatest risk when putting an implant in while the radial nerve is at risk when taking the implant out.
The nerves aren't deliberately cut during the procedure, so that's not the issue. Pulling on the nerve and exposure to heat from the cement used to hold the implant in place are two factors in nerve irritation or damage. Fortunately, the problem is transient or temporary. It takes a couple of weeks, but the symptoms usually go away.
Problems may persist even after corrective surgery. The final outcome can be very disappointing for both the surgeon and the patient. Considerable training and experience are required before a surgeon adds this particular procedure to his or her schedule.
Newer implants with improved designs have reduced implant-related complications. Future advancements in implant design and/or surgical technique may bring more surgeons to the table for this procedure.
Jaehon M. Kim, MD, et al. Complications of Total Elbow Arthroplasty. In Journal of the American Academy of Orthopaedic Surgeons. June 2011. Vol. 19. No. 6. Pp. 328-339.