Orthopedic Coding Alert

The typically used code for reverse shoulder arthroplasties may not earn you as much as 2 alternatives.

By: David V. Janeway, MD, president of Orthopaedic Specialists of the Carolinas and director of the Outpatient Orthopaedic Surgery Center at Forsyth Medical Center in Winston Salem, N.C.

Coding for shoulder procedures has always been difficult, mainly because of the shoulder's intricate anatomy, the many procedures orthopedists perform on the shoulder -- which often occur during the same operative session -- and the range of codes that are available for reporting shoulder procedures.

The good news: Shoulder coding has become easier in the past few years because of the addition of new codes for some of the common shoulder procedures that previously did not have codes.

As you know, practitioners develop new surgical procedures and techniques frequently, and new CPT and ICD-9 codes also emerge every year. However, it sometimes takes years to create appropriate CPT codes for the new procedures. Let us attempt to dispel some uncertainty here.

Example: The reverse shoulder arthroplasty is a relatively new procedure that has many coders asking questions about the differences between it and the regular shoulder replacement, and how to properly code the procedure.

Short explanation: The traditional shoulder arthroplasty replaces a patient's existing anatomy by replacing a ball with a ball, and a socket with a socket. But many of you may wonder: What's the meaning of this reverse total shoulder concept? Reverse total shoulder replaces the ball with a socket and the socket with a ball, thus the "reverse" portion of the term. But some questions still linger, such as "How does that happen" and "Why choose this method?"

Syllabus: Let's start with some history of the reverse shoulder, then review the anatomy of the shoulder, and then find out how the reverse shoulder really works.

Widespread use of the reverse shoulder in the U.S. has only occurred in the last few years. But doctors have performed it in Europe, and especially in France, for much longer. Dr. Paul Grammont designed the first modern working device, and all prostheses in use in the U.S. are similar to this design. Physicians performed more than 20,000 shoulder arthroplasties in 2007.

Because of the aging baby boomers, it is estimated that the number will increase to more than 60,000 by the year 2020. The number of total shoulder replacements pales in comparison to total hips and knees. Estimates indicate more than 700,000 hip and knee replacements per year.

Anatomy breakdown: The anatomy of the shoulder allows for a very large range of motion about the body. A healthy shoulder has forward flexion of 180 degrees, abduction to 160 degrees, and 90 degrees of internal and external rotation. (Note: For a visual depiction of major components of shoulder anatomy, reference the shoulder graphic on the facing page.)

The scapula, or shoulder blade as it is commonly known, is divided into the body and the glenoid. The scapular body includes the coracoid process and the scapular spine, which joins with the acromion process.

The coracoid process is the origination of the pectoralis minor, short head of the bicep, and the coracobrachialis muscles. The coracoacromial and coracohumeral ligaments also attach here.

The scapular spine and the acromion provide part of the origin of the deltoid. The acromion is also an attachment for the CA ligament and the AC joint, and is frequently a source of impingement.

The glenoid is the shallow socket of the shoulder. It is lined with articular cartilage. The humeral head is the superior, or top end, of the humerus. It is also lined with articular cartilage. This joint has been likened to a golf ball sitting on a tee.

The clavicle joins the scapula at the acromion connecting the anterior, or front part, of the shoulder to the body through the sternoclavicular joint. The scapula attaches through muscular connections including the trapezius, rhomboids, teres major, and levator scapulae on the posterior, or back side, of the shoulder.

The deltoid muscle forms the rounded contour of the shoulder. Bodybuilders want to build this muscle to get the classic cannonball shape. This muscle supplies the bulk of lifting strength for the shoulder.

The rotator cuff, consisting of the subscapularis, supraspinatus, infraspinatus, and teres minor, keep the humeral head centered on the glenoid allowing the deltoid to lift the shoulder normally. While the shape of the glenoid-humeral joint does allow great motion, it does not have bony stability.

The joint capsule, superior, middle, and inferior glenohumeral ligaments, and the labrum increase stability. The labrum is a structure that deepens the socket of the shoulder. I like to describe the glenoid as the bottom of a pie pan and the labrum as the edge of the pan. The labrum is frequently torn in shoulder dislocations.

Other commonly injured ligaments about the shoulder include the acromio-clavicular and coraco-clavicular ligaments, which provide stability to the distal, or outer end, of the clavicle.

Injuries to these result from shoulder separations. The pectoralis major and latissimus dorsi muscles attach to the proximal humerus shaft below the rotator cuff and can be used for tendon transfers.

Shoulder anatomy, or patho-anatomy, is the causative factor leading to reverse shoulder arthroplasty. Cuff tear arthropathy is the end result of chronic rotator cuff tear. The humeral head is no longer centered in the glenoid. It typically buttonholes through a defect in the rotator cuff, usually the supraspinatus and infraspinatus.

Eventually, the humeral head articulates with the acromion and abnormal bony wear occurs. Pain, loss of motion, and loss of function occur.

At this point, the humeral head cannot be centered on the glenoid and the rotator cuff is irreparable. This typically occurs in older patients; and in a patient older than 70, this is the primary indication for reverse shoulder arthroplasty. Another developing indication is a four-part fracture of the proximal humerus in an elderly patient.

What is the reverse shoulder? Reverse shoulder replacement is basically a salvage operation that restores function by muscle substitution for the rotator cuff. This operation offers functional restoration that was previously unavailable.

During the operation, the glenoid, or socket of the shoulder, is replaced with a glenoid base plate, which allows attachment of a glenosphere, thus replacing a socket with a ball. The base plate is attached with a central peg or screws along with peripheral screws, depending on the brand used.

In addition, the humeral head is removed and a stem is placed in the proximal humerus that allows placement of a socket. Polyethylene sockets of varying thicknesses can be used to balance and stabilize the shoulder, thusly replacing a ball with a socket.

This configuration allows the humeral head to move inferiorly and laterally, restoring the center of motion to the glenoid. In essence, this lengthens the arm about 14 mm. This arm lengthening allows the deltoid muscle to lift the arm while the humerus pivots off of the glenosphere.

Patient treatments: The patient will usually spend one to two days in the hospital. Then, the arm is held in a shoulder immobilizer for approximately six weeks. Patients undergo passive pendulum exercises for five minutes, five times a day. Active motion of the elbow, wrist, and hand is allowed.

At the six week post-op appointment, the physician removes the immobilizer and then more aggressive strengthening exercises commence during physical therapy visits. Typically, patients will note decreased pain, increased strength, and increased range of motion.

However, external rotation can remain weak. At the time of surgery, some surgeons perform latissimus transfers, to help strengthen external rotation.

As with any surgery, complications may occur. Possible complications may include infection, dislocation, scapular notching, and fracture.

Infections can cause a return to the operating room to perform irrigation and debridement, as well as glenosphere and polyethelene exchange. Chronic or severe infections may require removal of the prosthesis and placement of an antibiotic spacer.

Coding complications: As with all returns to the operating room within the 90-day global period, you will need to remember to append the correct modifier to the CPT code, and change the diagnosis code from the reason for the primary surgery to the reason for this second procedure.

If the 90-day global period has expired no modifier will be needed, but you will still need to change the diagnosis code to reflect the condition requiring the second procedure.

To finish, coding for the reverse shoulder procedure is straightforward, yet it can be a little confusing. There are three ways to code for the procedure at this time:

First way: First of all, it is entirely correct to code the reverse shoulder just as you would the standard shoulder arthroplasty, with 23470 (Arthroplasty, glenohumeral joint; hemiarthroplasty). The health care field is always developing different techniques to enhance and strengthen procedures, but at the end of the day the reverse shoulder is still a total shoulder arthroplasty. This is typically the way that I code my reverse shoulders.

Next way: Another way coders are documenting the reverse shoulder procedure is with the unlisted procedure code 23929 (Unlisted procedure, shoulder).

Because the procedure is more technically demanding and the work involved is more difficult, some physicians feel strongly that it merits different coding and reimbursement. These physicians feel that the reverse procedure is about 20 percent more difficult and therefore should be reimbursed at 120 percent of the typical payment for a shoulder arthroplasty, so they reflect that in the fee.

If you decide to opt for the unlisted procedure code, you should drop the claim to paper and submit it to the insurance company along with the operative report and a KISS (Keep It Simple, Stupid) letter explaining the procedure and the reasons it requires a higher reimbursement.

Last option: The other way to code for the procedure is to append modifier 22 (Increased procedural services) to 23470 and increase the fee according to the more demanding work involved.

If the surgeon documents more extensive work than is typically encountered in a total shoulder, appending modifier 22 can be a viable option, but remember that the modifier should not be misused. As with the unlisted procedure code, you will need to send in a paper claim along with the operative report and a KISS letter.

Hopefully, you now have a better understanding of the shoulder and this relatively new reverse shoulder arthroplasty procedure that is quickly gaining popularity.

I would encourage you to ask questions of the physicians you work for when you are confused about anatomy or procedures that the surgeons perform in your practice. As you know, orthopedic surgeons love what they do for a living and love to talk about the procedures they perform, so take advantage of that openness and let us clarify any anatomical or coding issues you may have.