Current Trends in the SLAP Repair of the Shoulder
SLAP stands for superior labral anterior posterior and refers to a tear of the labrum located around the rim of the acetabulum (shoulder socket). The labrum is a ring of fibrous cartilage around the shoulder socket. It helps support and hold the round head of the humerus (upper arm bone) in the shallow socket.
The superior labrum is located along the top of the socket. It is attached loosely by elastic connective tissue. A force or load through the shoulder that is greater than the tensile strength of the thick connective tissue can cause tearing of the structures.
There are four types of SLAP lesions. The groups are based on severity. Type 1 occurs most often in older adults. Fraying and thinning of the labrum is most common with this type of SLAP lesion. If surgery is called for, the surgeon will shave off any fragments and smooth the remaining edges of the labrum.
The other types describe the extent of injury. For example, in a type 2 SLAP injury, the biceps anchor where the labrum attached is detached. There may be some frayed edges of the labrum as well.
Type 3 is a bucket-handle shaped tear in the labrum but the biceps anchor is not disturbed. Type 4 has a similar bucket-handle shape that extends all the way into the biceps tendon. Sometimes people have more than one type of tear at a time. Surgery is often needed to repair the more severe injuries.
The number of SLAP surgeries being done in the United States is increasing year-by-year. The reason(s) for this are not yet clear. By studying patient characteristics of people having the SLAP repair, this group of surgeons hopes to explain this trend.
Demographic information such as age, sex (male versus female), and geographic location where the surgery took place might shed some light on who, what, where, and why SLAP repairs are being done. This type of study is referred to as a descriptive epidemiology study. It was done by examining the insurance billing records of a national database, which are public but still maintain patient privacy.
Data collected on over 25,500 patients who had an arthroscopic SLAP repair was analyzed for a five-year period of time. There were four major findings:
What does all this information mean? That's a good question but the answer is not entirely clear just yet. For example, does the difference in numbers of procedures between men and women suggest men are more active and injured more often? Or do surgeons tend to repair SLAP tears in men more readily than in women (a gender bias)?
Why are there more older adults having this surgery? It may be because newer repair techniques (e.g., with suture anchors) makes this procedure more successful in that age group than ever before. But other studies have clearly shown that tenotomy (tendon is cut) or tenodesis (stitching tendon back to the bone) procedures have better results than SLAP repairs in patients over 40 -- so why are surgeons still performing SLAP repairs on this age group?
There is also no clear reason why geographical differences exist. In fact, most of the data collected in this study raised more questions than they answered. The authors suggest further comparative studies to find out the "whys" for the "what" they uncovered. Studies are also needed to look at results of treatment for each procedure and with the demographic variables in mind.
Alan L. Zhang, MD, et al. Demographic Trends in Arthroscopic SLAP Repair in the United States. In The American Journal of Sports Medicine. May 2012. Vol. 40. No. 5. Pp. 1144-1147.