SLAP in the face for shoulder surgery

I have always been sceptical of some shoulder procedures, and the increasing rate of shoulder surgery and the lack of high quality evidence worries me. I started a simple blog post about one particular operation (for “SLAP” lesions) and found a tale of research waste, bad science, overdiagnosis and overtreatment.

A common finding in the shoulder is the “SLAP” lesion – a tear of the upper ‘labrum’ or rim of the socket, often with damage to the associated biceps tendon attachment. Repairing them is a common procedure, usually done through an arthroscope. A randomised placebo trial has been reported, which showed that surgery for a SLAP lesion was no better than not operating.

Like other tears in the shoulder (usually the rotator cuff) SLAP lesions can be caused by an acute (traumatic) injury (usually in younger people) or just degeneration over time (these are commonly found in people over 40, even without symptoms). They are classified as types I, II, III and IV, the most common being Type II. Surgical repair is commonly done for these, but the indications for surgery and the purported benefits have not been clearly shown in high quality studies. There appears to be some evidence that younger people with acute (traumatic) tears do better than older people or those without traumatic tears, but nothing about whether anybody does better with surgery compared to not operating.

Most of the research until now has come from case series that show that people get better if you repair them, or if you debride (remove) the tear, or if you re-attach the biceps tendon, or if you release (cut) the biceps tendon. When nearly everyone gets better no matter what you do, it makes me think that they were likely to get better anyway. Especially when it is not even clear how to diagnose it in the first place (here).

I did a brief search of research published on SLAP lesions and found 181 papers – not that many really. Nearly all covered either how to diagnose it or some aspect of surgical technique. None of them compared surgery to non-operative treatment. There was one randomised trial (RCT, here), and it compared repair to no repair during surgery to fix a rotator cuff tear. It showed no benefit in repairing the SLAP lesion. But nothing on what to do with an isolated SLAP lesion.

There was a recent systematic review (here). They found 26 studies, but the quality of studies was low, and none of them compared surgery to non-operative treatment unless you count the one RCT they found, which I mentioned above. The results of the review showed that the research was so poor that an accompanying editorial (here) called for better research.

Some researchers in Norway must have thought that good evidence was needed. They did a placebo surgery trial (here) in which all patients had an arthroscopy (to make sure the diagnosis was right and there was no other pathology) then assigned 118 of them to three groups: repair of the labrum, tying down (tenodesis) the biceps tendon, or nothing. The patients, and those doing the follow up and the analysis were blinded. Age varied between 18 and 64 (average 40). The study measured shoulder pain and function regularly up to 24 months and found no important differences between any of the groups, except the surgical groups had more stiffness and did a little worse in the early stages. There were a few re-operations in each group and only a few in each group were lost to follow up.

The bottom line

So what do we have – a commonly performed operation for a condition that may or may not be associated with symptoms, with abundant research looking at different aspects of surgery but without any credible research assessing whether surgery works at all (until now). Why wasn’t this research done before? Because effectiveness was assumed: “It’s torn, isn’t it? then let’s repair it”. This is a classic example of research waste, unnecessary surgery, poor science and an unshakeable belief that operating must be better than not operating.