There is a debate in the literature about which treatment is best for the long-term management of frozen shoulder surgery, physiotherapy, or both. The British FROST process is intended to shed light on the situation.
Frozen shoulder, also known as adhesive capsulitis, is a common disease in all areas of physiotherapeutic practice. The condition commonly affects people over the age of 50 and is more common in people with diabetes, cardiovascular disease, trauma, stroke, or neurosurgery.
The diagnosis of adhesive capsulitis is usually based on clinical features of insidious pain in the shoulder with increasing stiffness and clinical findings of limited active and passive external rotation without creptius.
Frozen shoulder | The cold hard facts
Frozen shoulder can resolve spontaneously, but up to 40% of patients report persistent symptoms up to and over 4 years after onset. There are a number of treatment options, including manipulation under anesthesia, where the capsule is torn, and arthroscopic capsule release, where the capsule is cut. Physiotherapy instead of or as a complement to surgery is an option for people with frozen shoulder, but there is some debate about which treatment will work. The British British Frozen Shoulder Physiotherapy Directive recommends exercise and manual therapy either in isolation or as a supplement to intra-articular glucocorticoid (steroid) injection, manipulation or capsule release.
It is not known whether structured physiotherapy or either MUA or arthroscopic release followed by physiotherapy is more effective. Recent systematic reviews have highlighted this gap in understanding and this is why the UK's FROST study was created. To evaluate the effectiveness and cost-effectiveness of three treatment pathways for treating adults with a frozen shoulder: two commonly used surgical procedures in the UK's National Health Service (NHS) hospitals (manipulation and capsule release) and our specially designed non-surgical physiotherapy pathway.
Methods
The British FROST study is the largest RCT comparing early structured physiotherapy, manipulation under anesthesia and arthroscopic capsular release. It was a large multicenter RCT with three parallel groups of patients referred to secondary care for treatment of the primary frozen shoulder. All patients were randomized using a computer algorithm and in a manner that would reduce the impact of the presence of diabetes.
35 hospital sites across the UK were involved, involving 90 surgeons and 285 experienced physical therapists familiar with the treatment protocol used in the study. This early structured physical therapy was a multi-component physical therapy intervention in secondary care, including steroid injection, that we developed using recommendations from national guidelines and a Delphi study of shoulder specialist physical therapists. The operative group was still running a post-procedural physiotherapy program developed using systematic review, survey, and Delphi consensus methods.
The full details of the physiotherapy programs involved in this RCT are fully published and available free of charge.
Both surgical interventions were carried out as day cases within 18 weeks after the randomization.
The primary outcome measure was the Oxford Shoulder Score and the primary endpoint was 12 months after randomization. Secondary outcomes included QuickDASH, EuroQOL-5, and VAS scores, all of which were collected at baseline, 3 months, 6 months, and 12 months after randomization.
A total of 914 participants took part in the study, with 503 randomly assigned to the three treatment groups; 201 MUA, 203 arthroscopy and 99 for physiotherapy. All test profile and result data are available in the article.
Results and clinical significance
After 12 months, the participants who had undergone an arthroscopic capsule release had the highest OSS value with 40.3, followed by MUA with 38.3 and early structured physiotherapy with 37.2 points. However, after 3 months the capsule release has the lowest OSS value. A similar pattern of results was observed when using QuickDASH. While these results are statistically significant, they are unlikely to be central. A score of 5 on the OSS is believed to be clinically significant. As you can see in the graph on the right, the results are very closely summarized 12 months after randomization.
In view of the adverse results of the study and the cost analysis, arthroscopic capsule release was associated with higher risks and MUA was the cheapest treatment option.
All three treatment options led to significant improvements in pain and function, and none of the treatments was clearly superior. Possibly a minor clinically important benefit of capsule release over physiotherapy could be seen in a larger population. The physical therapy program could be more accessible than the surgical interventions and is less expensive, but does not offer as much improvement as the arthroscopic release, however the physical therapy is far safer.
