No benefit of arthroscopy in subacromial shoulder pain
Authors: Berend W Schreurs, Stephanie L van der Pas
Journal: The Lancet (2017)

Since its introduction nearly 100 years ago,1Takagi K Practical experiences using Takagi's arthroscope.J Jpn Orthop Assoc. 1933; 8: 132Google Scholar arthroscopy of the knee has revolutionised the care of patients with meniscal lesions, ruptures of the anterior cruciate ligament, and cartilage damage. Although knee arthroscopy has proved to be an asset that is highly beneficial to many patients, it is not a panacea for all knee problems. The clinical benefit is especially questionable for patients with degenerative osteoarthritis: in a trial using a sham surgery,2Moseley JB O'Malley K Petersen NJ et al.A controlled trial of arthroscopic surgery for osteoarthritis of the knee.N Engl J Med. 2002; 347: 81-88Crossref PubMed Scopus (1148) Google Scholar knee arthroscopy had no effect, and this finding was confirmed in another study.3Kirkley A Birmingham TB Litchfield RB et al.A randomized trial of arthroscopic surgery for osteoarthritis of the knee.N Engl J Med. 2008; 359: 1097-1107Crossref PubMed Scopus (524) Google Scholar The difficulty of implanting evidence-based surgery in daily surgical practice is highlighted by the large number of patients who still have arthroscopy in osteoarthritic knees.4Thorlund JB Hare KB Lohmander LS Large increase in arthroscopic meniscus surgery in the middle-aged and older population in Denmark from 2000 to 2011.Acta Orthop. 2015; 85: 287-292Crossref Scopus (128) Google Scholar The possibility of arthroscopy in joints other than the knee has also been explored. Shoulder arthroscopy has been taken up widely,5Colvin AC Egorova N Harrison AK Moskowitz A Flatow EL National trends in rotator cuff repair.JBJS Am. 2012; 94: 227-233Crossref Scopus (446) Google Scholar, 6Judge A Murphy RJ Maxwell R Arden NK Carr AJ Temporal trends and geographical variation in the use of subacromial decompression and rotator cuff repair of the shoulder in England.Bone Joint J. 2014; 96: 70-74Crossref PubMed Scopus (116) Google Scholar although indications are not clearly defined. Two areas that are possibly indicated are the glenohumeral joint for intra-articular lesions and the subacromial area that is extra-articular. An impingement syndrome of the subacromial area is responsible for up to 70% of all shoulder problems.7Mitchell C Adebajo A Hay E Carr A Shoulder pain: diagnosis and management in primary care.BMJ. 2005; 331: 1124-1128Crossref PubMed Scopus (296) Google Scholar This impingement arises due to the restricted space between the acromion and the glenohumeral head, where rotator cuff tendons slice back and forth in abduction and ante version, facilitated by a subacromial bursa. An impingement of these rotator cuff tendons occurs frequently in patients older than 40 years, with typical complaints such as a painful arc.8Neer CS Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report.JBJS Am. 1972; 54: 41-50Crossref Scopus (1900) Google Scholar To overcome this impingement problem, in 1972 Neer8Neer CS Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report.JBJS Am. 1972; 54: 41-50Crossref Scopus (1900) Google Scholar proposed open decompression of this area, removing osseous spurs from the caudal side of the acromion, often combined with release of the coracoacromial ligament and a bursectomy. An arthroscopic version of this popular procedure was developed and is now frequently undertaken, with an increase of nearly ten times in England from 2500 surgeries in 2000 to 21 000 in 2010.6Judge A Murphy RJ Maxwell R Arden NK Carr AJ Temporal trends and geographical variation in the use of subacromial decompression and rotator cuff repair of the shoulder in England.Bone Joint J. 2014; 96: 70-74Crossref PubMed Scopus (116) Google Scholar However, as correctly pointed out in The Lancet by David Beard and colleagues9Beard DJ Rees JL Cook JA et al.on behalf of the CSAW study groupArthroscopic subacromial decompression for subacromial shoulder pain (CSAW): a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial.Lancet. 2017; (published online Nov 20.)http://dx.doi.org/10.1016/S0140-6736(17)32457-1Summary Full Text Full Text PDF Scopus (222) Google Scholar for the Can Shoulder Arthroscopy Work (CSAW) study group, the scientific clinical evidence in favour of this type of shoulder surgery is scarce. In Beard and colleagues' multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial, 106 patients were assigned to decompression surgery, 103 to arthroscopy only, and 104 to no treatment. The primary outcome was the Oxford Shoulder Score at 6 months, analysed by intention to treat.9Beard DJ Rees JL Cook JA et al.on behalf of the CSAW study groupArthroscopic subacromial decompression for subacromial shoulder pain (CSAW): a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial.Lancet. 2017; (published online Nov 20.)http://dx.doi.org/10.1016/S0140-6736(17)32457-1Summary Full Text Full Text PDF Scopus (222) Google Scholar The study group should be commended for undertaking this difficult trial. Two factors that made an assessment of effect difficult were the rather high level of non-compliance in the groups (24 [23%], 43 [42%], and 12 [12%] of the decompression, arthroscopy only, and no-treatment groups, respectively, did not receive their assigned treatment, making the groups more similar and thus differences harder to detect) and the long waiting list, with a waiting time of up to 4 months considered to be acceptable. Thus, patients who were only 2 months post surgery were compared with patients who were 6 months into the no-treatment option. However, the outcome was still remarkable. There was no difference in the primary outcome between the arthroscopic decompression and arthroscopy only groups (decompression mean 32·7 points [SD 11·6] vs arthroscopy mean 34·2 points [9·2]; mean difference −1·3 points [95% CI −3·9 to 1·3], p=0·3141). This is an intriguing finding, showing that subacromial decompression does not affect the clinical outcome. Additionally, although patients in the surgical groups had statistically better outcomes than the no-treatment group, the differences were small and not clinically important. Although the sizes of the differences are difficult to interpret because of the high non-compliance levels and long waiting list, the differences themselves might be attributed to the placebo effect after surgery. Another explanation, but also a criticism of the study design, is that the no-treatment group was left alone (one reassessment appointment with a specialist shoulder clinician 3 months after study entry but no intervention) in this study with no offered rehabilitation programme, unlike the surgical groups. The findings send a strong message that the burden of proof now rests on those who wish to defend the standpoint that shoulder arthroscopy is more effective than non-surgical interventions. Hopefully, these findings from a well respected shoulder research group will change daily practice. The costs of surgery are high, and although the low occurrence of complications might suggest that the surgery is benign,10Brislin KJ Field LD Savoie FH Complications after arthroscopic rotator cuff repair.Arthroscopy. 2007; 23: 124-128Summary Full Text Full Text PDF PubMed Scopus (216) Google Scholar there is no indication for surgery without possible gain. Therefore, the focus on the cure for these patients should be on developing effective conservative treatment programmes based on exercise and probably combined with tape, manual therapy, extracorporeal shockwave lithotripsy, or laser treatment.11Steuri R Sattelmayer M Elsig S et al.Effectiveness of conservative interventions including exercise, manual therapy and medical management in adults with shoulder impingement: a systematic review and meta-analysis of RCTs.Br J Sports Med. 2017; 51: 1340-1347Crossref PubMed Scopus (123) Google Scholar The emerging pattern that arthroscopic interventions might, for some indications, not be more beneficial than non-surgical options should also be taken into consideration when the decision for hip arthroscopy is made. There is a worrisome trend to do arthroscopy of the hip, including in elderly patients with degenerative hips.12Montgomery SR Ngo SS Hobson T et al.Trends and demographics in hip arthroscopy in the United States.Arthroscopy. 2013; 29: 661-665Summary Full Text Full Text PDF PubMed Scopus (252) Google Scholar The orthopaedic field is in urgent need of well designed studies that assess the effectiveness of this kind of surgery in osteoarthritic hips.13Griffin DW Kinnard MJ Formby PM McCabe MP Anderson TD Outcomes of hip arthroscopy in the older adult: a systematic review of the literature.Am J Sports Med. 2016; 45: 1928-1936Crossref PubMed Scopus (79) Google Scholar Arthroscopy is a useful procedure that benefits many patients. However, there are serious concerns that a substantial number of these procedures are done in patients with mostly degenerative diseases, and therefore will not be curative. Unfortunately, it will be demanding to change daily orthopaedic practice as both patients and surgeons believe sincerely that the problems will be reduced after arthroscopic surgery. Evidence such as that reported by the CSAW study group should help to change such views and improve practice. We declare no competing interests. Arthroscopic subacromial decompression for subacromial shoulder pain (CSAW): a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trialSurgical groups had better outcomes for shoulder pain and function compared with no treatment but this difference was not clinically important. Additionally, surgical decompression appeared to offer no extra benefit over arthroscopy only. The difference between the surgical groups and no treatment might be the result of, for instance, a placebo effect or postoperative physiotherapy. The findings question the value of this operation for these indications, and this should be communicated to patients during the shared treatment decision-making process. Full-Text PDF Open Access