A black-shouldered kite just after a meal, a beautiful picture that is CC and made by David Jenkins.

Although I’m not a shoulder surgeon, I find the rotator cuff injuries fascinating. The rotator cuff is a group of muscles that surround the shoulder, providing motion and stability. Out of the four muscles, the top one is usually the most troublesome, the supraspinatus. It has a sensitive tendon that can both become irritated and cause pain and be a vital part of a rotator cuff rupture. In this post I’m going to focus on the rupture part, also commonly known as a rotator cuff tear. Note, this is not a complete review of this vast subject, more my personal reflections.

Acute tears

Acute cuff tears occur with a distinct loss of shoulder function in direct relation to trauma, also know as pseudoparalysis with less than 45 degrees of motion in both active forward elevation and abduction. This is a fairly uncontroversial injury and should be treated early on with surgery. If you wait more than 3 months the muscle starts to degenerate into fat, the body decides surprisingly fast that the muscle is no longer working and turns it into fat. Unfortunately this process is irreversible, which is why this should be operated fairly quickly.

Chronic tears

The chronic injury is by far the most common one, and also increasing with age. Cuff repair surgery is among the top 10 orthopaedic procedures in the US and although common it is surprisingly controversial. The main argument is the lack of proper randomized clinical trials, many trials try to address how the injuries should be repaired – few show that it matters.

In a meta-analysis on cadaver studies (see Reilly et al) full thickness tears occur in about 1/5 of the asymptomatic population. This indicates that just having a rotator cuff injury is not indicative that it actually causes pain, and some argue that the active physiotherapy due to the surgery or that the subacromial decompression performed during the cuff repair are the main causes for improvement. Even if there isn’t a subacromial decompression performed, the bursa is resected in order to gain access and thus it is very difficult to study only the repair procedure.

Another neat study from Moosmayer et al (Norway) followed a small cohort of patients with asymptomatic where about a third developed symptoms within three years. While the study is interesting as it shows the acute lack of long-term follow-up studies in orthopaedics, it has some methodological issues with the definition of the cohort – for instance the age, gender and occupation is not reported in the study. Furthermore, they should have tried to elicit some kind of control population that has not a cuff-tear to see how many here develop pain in that group. Even so, it remains as an interesting article that shows how important cohort studies with long-term follow-up are, in my opinion three years is a rather short follow-up and I hope that the group will continue following this cohort for another 5-10 years.

The jury is still out regarding the optimal treatment of these injuries. Many show improved function with repair but most fail to show that successful repair, i.e. no re-tear, is better than those with a re-tear. DeHaan et al’s review on double-row vs single-row is an interesting read on the subject.

I can also recommend a look at Hanna Björnsson Hallgren’s thesis for a very nice overview of the painful shoulder. She was awarded the thesis of the year and I got to talk to her recently – she has an excellent understanding of this complicated subject.

1. S. Moosmayer, R. Tariq, M. Stiris, and H.-J. Smith, “The Natural History of Asymptomatic Rotator Cuff TearsA Three-Year Follow-up of Fifty Cases,” J Bone Joint Surg Am, vol. 95, no. 14, pp. 1249–1255, Jul. 2013.
2. P. Reilly, I. Macleod, R. Macfarlane, J. Windley, and R. Emery, “Dead Men and Radiologists Don’t Lie: A Review of Cadaveric and Radiological Studies of Rotator Cuff Tear Prevalence,” Ann R Coll Surg Engl, vol. 88, no. 2, pp. 116–121, Mar. 2006.
3. A. M. DeHaan, T. W. Axelrad, E. Kaye, L. Silvestri, B. Puskas, and T. E. Foster, “Does Double-Row Rotator Cuff Repair Improve Functional Outcome of Patients Compared With Single-Row Technique? A Systematic Review,” Am J Sports Med, vol. 40, no. 5, pp. 1176–1185, May 2012.
4. Hanna Björnsson Hallgren’s excellent thesis chosen by SOF to be the Swedish thesis of the year: Treatment of Subacromial Pain and Rotator Cuff Tears.