Sunday 21 May 2017

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.


  1. A fair amount of shoulder pain is caused by anxiety and depression. Any type of procedure could act as a placebo. Many doctors do not recognize a patient as having anxiety or depression, so the cause of shoulder pain, unless trauma, is often blamed on repetitive motion or loading or other possibilities. Shoulders and necks react to "Flight, fight or freeze", and the muscle groups for each are not always the same for each emotional action or reaction.

  2. I think Rototor cuff surgery falls in the same camp largely. The only 1 or 2 RTCs that sued sham surgery showed no real difference.
    A new study is underway in Finland to look at acute traumatic tears. Doubt any of this will dent the HUGE market for these operations

    1. But the market for knee scopes was bigger, and that has been severely dented by a study from Finland.
      I am not aware of any published sham surgery studies of rotator cuff surgery??

    2. This should be out soon:

    3. Yes, and a similar study from Finland as well. Looks like the shoulder surgeons will be under a bit of pressure to support their practices - just like the knee surgeons have been.

  3. Any chance of a reference to the Norwegian study?

    1. Apologies. Link added to blog post above.

  4. Thanks for sharing. I wondered about the efficacy of SLAP repairs as well. The Norwegian doctors in this study are really physicians to look up to for their integrity and ability to question assumptions. In contrast JBJS (USA) published this in 1993,

    Results: The age-weighted mean total societal savings from rotator cuff repair compared with nonoperative treatment
    was $13,771 over a patient’s lifetime. Savings ranged from $77,662 for patients who are thirty to thirty-nine years old to a
    net cost to society of $11,997 for those who are seventy to seventy-nine years old. In addition, surgical treatment results
    in an average improvement of 0.62 QALY. Societal savings were highly sensitive to age, with savings being positive at the
    age of sixty-one years and younger. The estimated lifetime societal savings of the approximately 250,000 rotator cuff
    repairs performed in the U.S. each year was $3.44 billion.

    A great work of propaganda but bad science- so many incorrect assumptions...

  5. Nothing you haven't written about before just a little more ammo!

    Yours is a very worthwhile blog. Thanks.

  6. Surely any surgery should only be done if it is absolutely necessary given the impact on brain function of anaesthetics, particularly as people get older, and the trauma of the physiological shock to the body, which all surgery must bring, even if it is not recognised or studied?

    1. Thanks. I am not sure about the pure negative effects of surgery and anaesthesia, but they entire process certainly has risks (infection, surgical error, inadvertent damage etc.) and costs a lot of money, so the burden of proof should be on those in favour of surgery.


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