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Shoulder Research Paper

Painful shoulders account for 2.4% of all GP consultations in the UK, and can make it difficult to work, drive or get dressed. Decompression surgery is often used to treat people with shoulder impingement, when a tendon rubs and catches in the shoulder joint. The surgery has become increasingly popular and is carried out on approximately 21,000 people a year in the UK.

Newly published in The Lancet, results from the first placebo-controlled trial in shoulder surgery, suggest that decompression surgery may not be as effective as first thought. The findings have revealed that the surgery is no better at relieving pain than a placebo and that while both options were fractionally more effective at treating pain than having no surgery at all, the differences were minimal and unlikely to offer noticeable relief.

Conducted by researchers from the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, with the support of the British Elbow and Shoulder Society (BESS), the study findings have fuelled doubts around the value of the operation and the authors recommend that patients considering the operation should be notified of these results, so that they can make an informed decision about the best treatment for them.

Co-chief investigator Professor Andrew Carr, National Institute of Health Research (NIHR) Biomedical Research Centre, University of Oxford, said: ‘Over the past three decades, patients with this form of shoulder pain and clinicians have accepted this surgery in the belief that it provides reliable relief of symptoms, and has low risk of adverse events and complications. However, the findings from our study suggest that surgery might not provide a clinically significant benefit over no treatment, and that there is no benefit of decompression over placebo surgery.’

Co-chief investigator Professor David Beard and Professor of Musculoskeletal Sciences, added: ‘Our findings call into question the value of shoulder decompression surgery for this group of patients, and should be communicated to patients and doctors considering this type of surgery. In light of our results, other ways to treat shoulder impingement could be considered, such as painkillers, physiotherapy and steroid injections.’

The study involved 313 patients suffering persistent pain and symptoms for at least three months despite receiving physiotherapy and steroid injections. 51 surgeons in 32 hospitals in the UK took part in the trial and patients were randomised to receive one of three different treatment options, decompression surgery, placebo surgery or no treatment all.

Decompression surgery is a keyhole surgery that involves removing a small area of bone and soft tissue in the shoulder joint to open up the joint and prevent rubbing or catching when the arm is lifted. In the placebo surgery, surgeons conducted a procedure to look inside the joint where the joint was inspected but no tissue was removed.

Both surgeries were completed as keyhole procedures to ensure that patients were not aware of which surgery they had had. Surgery participants also had one to four physiotherapy sessions afterwards, while those having no treatment only had a check-up appointment three months after the start of the trial.

At six and 12 months post trial participants were asked to feedback about their symptoms and level of pain, rating their symptoms from 0-48, (with a higher number meaning less pain). Overall, symptoms diminished in all three groups from the start of the trial. However it was found that decompression surgery offered no greater benefit to shoulder pain than placebo surgery.

The group who did not receive surgery also improved over time, to the point that patients that were treated with surgery were only slightly more improved than those who were not. However, the authors did not find this difference in improvement to be clinically significant and believe that it can be attributed to a number of other factors.

Although the study did not assess the recurrence of pain after a year, the authors note that it is unlikely that one group would show significant improvements over another long-term, when they have not done so in the year post surgery.

Natalie Carter, head of research liaison and evaluation at Arthritis Research UK, comments: ‘This study suggests that other treatments such as physiotherapy can be just as effective as shoulder surgery, and should be taken into consideration with patients considering surgery and could influence the decisions made by health providers.

‘Often shoulder pain can be short-lived, but if you’re experiencing shoulder pain which continues for more than two weeks, or gets worse, speak to your doctor or a physiotherapist in case you have a more complex problem.’

Considering the broader value of the research, Dr Berend Schreurs of Radboud University Medical Center, the Netherlands, said: '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, there is no indication for surgery without possible gain.’

Etiology and pathology

OA, also known as degenerative joint disease, is defined as non-inflammatory degeneration of the cartilage and narrowing of the glenohumeral joint space. Radiographic findings of glenohumeral OA include joint space narrowing, circumferential osteophyte formation, subchondral cyst formation, posterior wear or bone loss of the glenoid, and/or subchondral sclerosis. Arthritis of the shoulder has many etiologies, including primary (idiopathic) and secondary (post-traumatic or developmental). Primary glenohumeral OA is considered rare [8], yet it is becoming an increasingly recognized source of pain and disability in the shoulder. Overuse and trauma have been correlated with increased risk of developing degenerative joint disease [9]. Increased intrinsic glenoid retroversion has been shown to lead to increased wear of the posterior glenoid, and these individuals are prone to earlier onset OA [10]. Chronic overuse of the shoulder can lead to excessive wear of the articulating surfaces with eventual thinning of the articular cartilage [11].

Post-capsulorraphy arthropathy is arthritis associated with surgical procedures for the treatment of instability, particularly from over-tightening of the anterior soft tissues of the shoulder. Over-tightening of the soft tissues leads to reduced external rotation and increased compressive load on the posterior articular cartilage of the glenoid, resulting in accelerated development of arthritis in the shoulder. Mal-positioned and migrated hardware, such as suture anchors or loosened screws, may also cause mechanical damage to the glenohumeral joint cartilage [12]. More recently, thermal injuries from soft tissue shrinkage devices used during shoulder arthroscopy have led to chondrolysis, and eventual OA [2].

The radiographic findings described above are in contrast to arthritis associated with inflammation (e.g., rheumatoid arthritis). Rheumatoid arthritis in the shoulder typically presents with medial wear of the glenoid, absence of osteophyte formation, large cyst formation, and osteopenia.

Current treatment options for osteoarthritis

The management of shoulder OA typically begins with nonoperative modalities before surgery is considered. The mainstays of non-operative treatment include oral and injected analgesics and anti-inflammatory drugs, physical therapy, and lifestyle modifications [13]. The goal of physiotherapy is to increase joint range of motion and strengthen muscles of the scapular girdle. Arthritic joints are prone to stiffness, and the stiffness is often a source of pain. Joint infiltration of local analgesics, often combined with steroidal anti-inflammatory drugs, is common and is often performed in out-patient settings. Steroid injections and visco-supplementation may provide short-term pain relief and help physicians diagnose intra-articular pathologies [14,15]. Such treatments are not without risk, however, and may lead to chronic degenerative changes to the joint and attenuation of the soft tissues in and around the joint [16].

When nonoperative treatment options no longer alleviate symptoms and symptoms interfere with daily activities and sleep, surgical management is often considered (Table ​1). Treatment options include arthroscopic debridement, cartilage repair, and biological and arthroplastic replacement [17]. Arthroscopic debridement, with or without capsular release, may provide short-term relief of pain in the osteoarthritic shoulder; however, deterioration over time can be expected for most patients due to the loss of cartilage thickness and the inability to regenerate lost tissue. Some studies have demonstrated the benefit of this procedure as an early temporal bridge to arthroplasty [18,19].

Table 1

Procedures, advantages, and disadvantages for various surgical treatment modalities for severe osteoarthritis and rotator cuff disease

A major limitation to the consideration of an arthroplasty in a young patient is the longevity of the prosthesis. The rate of survival of a shoulder arthroplasty over the long term (15 to 20 years) is approximately 85% [20]. For young patients, alternatives are considered in order to avoid future revisions. Biologic resurfacing with a soft tissue interposition with or without humeral head replacement has led to controversial results [18,21-23]. Resurfacing with knee meniscus, Achilles allograft, anterior shoulder capsule, and other materials have all been reported. Early reports of biologic resurfacing were favorable, but recent mid-term results have indicated a high rate of failure and subsequent revision. Currently, glenoid resurfacing with biologic interposition is only recommended in young patients, in their third or fourth decade. Humeral head prosthetic resurfacing with stemless implants has also been considered in younger patients for humeral lesions [22]. The rationale is that a smaller resurfacing implant preserves proximal humeral bone stock, in the interest of future revision surgery. While this procedure has the potential advantage of minimal bone loss without humeral canal reaming, it is specific to treating small focal lesions or isolated humeral head arthrosis and may have little application in the setting of more severe OA [24-26].

Total shoulder arthroplasty (TSA) is the gold standard treatment for severe glenohumeral OA [27]. The growth rate for TSA continues to rise compared to other orthopedic joint replacement surgery rates [3]. Approximately 45,000 patients in the US undergo total shoulder arthroplasty or hemiarthroplasty each year [3]. A total shoulder arthroplasty involves replacement of the humeral head and prosthetic resurfacing of the glenoid (Figure ​1). A hemiarthroplasty refers to humeral head replacement alone.

Figure 1

Total shoulder arthroplasty for treatment of severe glenohumeral osteoarthritis. (A) Pre-operative radiograph of an arthritic shoulder with typical loss of normal joint space. (B) Post-operative radiograph after total shoulder replacement of both humeral...

Total shoulder arthroplasty offers reliable pain relief, predictable improvement of function, and improved quality of life for a variety of shoulder arthropathies, including primary OA [28]. The main concern with TSA is the potential for loosening of the glenoid component over time, as this represents the most common complication [29,30]. Fixation [31] and material composition [32] are also factors related to the success of prostheses, as dierent materials and implantation methods may influence osteolysis and risk of arthroplasty revision. Recent results, however, support the longevity of poly-ethylene glenoid resurfacing [23]. Improvements in glenoid component materials and engineering are an on-going subject of research.

Hemiarthroplasties are used mostly for select cases of arthritis, such as OA in a younger individual and rheumatoid arthritis in which bone loss precludes implantation of a glenoid component and rotator cuff arthropathy [28,33]. In general, hemiarthroplasty demonstrates inferior results when compared to TSA [27,34-36]; how-ever, such procedures may be more appealing in certain settings, such as for very young patients, patients with severe bone loss, and patients with avascular necrosis involving only the humeral head [37].

A reverse shoulder arthroplasty is arguably one of the most important contributions to the treatment of certain shoulder arthropathies in the past several years. Reverse total shoulder arthroplasty is indicated primarily in the setting of rotator cuff insufficiency and rotator cuff arthropathy, but has also been used for fracture treatment, revision of failed shoulder arthroplasty, and sequelae of trauma. Reverse TSA prostheses have a ball-in-socket design, with a semi-circumference ball being implanted in the glenoid and a stem with a concave polyethylene cap implanted in the humerus (Figure ​1). Rotator cuff arthropathy represents a spectrum of shoulder pathology characterized by rotator cuff insufficiency, diminished acromiohumeral distance, and arthritic changes of the glenohumeral joint [38]. Reversal of the components changes the biomechanics of the construct, allowing overhead elevation in the absence of a rotator cuff. A competent deltoid is critical for a successful reverse shoulder arthroplasty, as this becomes the primary actuator of the shoulder. Recently, some surgeons have expanded the use of this prosthesis to treat other shoulder conditions, such as irreparable rotator cuff tears without glenohumeral arthritis and rheumatoid arthritis; preliminary studies have had favorable short-term results [28,39].

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