The MSK Playbook: Frozen Shoulder

Key words: #MSKplaybook #Mindthesofttissuegap #frozenshoulder #MSKultrasound #SEM #Hydroditension

Introduction

Frozen shoulder (adhesive capsulitis) is a common condition within community musculoskeletal (MSK) interface services, which presents insidiously and significantly impacts patients’ quality of life and function.

In this blog, we discuss how a community-based pathway can permit early diagnosis through prompt referral to rehabilitation, alongside access to injection treatment and MSK ultrasound when there is diagnostic uncertainty. Close links with the shoulder orthopaedics team can also facilitate early escalation of patients with significant cuff tear or post-trauma. 

Figure 1: The MSK playbook: frozen shoulder

Bringing a one stop shop model to the diagnosis of frozen shoulder

Frozen shoulder is associated with significant disability during the acute and post-acute phases. Patients can often present to various primary care clinicians – general practitioners, first contact practitioners, or practice-based physiotherapists, depending on local staffing and resources. This is a challenge for the early diagnosis and management of frozen shoulder, as not all primary care services have the capacity to offer regular reviews and continuous rehabilitation alongside potential injection therapies.

Figure 2: Natural history of frozen shoulder(1)

A – Short episode of frozen shoulder with full resolution of symptoms 

B – Frozen shoulder with resolution of symptoms

C – Prolonged episode of frozen shoulder with chronic long-term deficit 

Frozen shoulder has a natural timeline for improvement; however, early diagnoses can assist patients to navigate treatment options. In short lived episodes or mild symptoms, this may mean a full resolution of symptoms with rehabilitation +/- injection therapy. In cases where the symptoms are more significant, prolonged or chronic, clear referral links for hydrodistension, and early treatment is key for accelerated recovery. Suprascapular nerve blocks can also be considered if there is appropriate expertise available.  

Figure 3: Summary of the initial phase of the community based MSK pathway for frozen shoulder

A focussed clinical history, examination, and X-ray (two views) can be used to rule out osteoarthritis; in most cases, this will confirm the diagnosis. However, if there is a suspicion of a significant rotator cuff tear (trauma) or tendinopathy, MSK ultrasound can help to rule in or rule out this diagnosis.

Background

  • Frozen shoulder is classified as either primary or secondary:
    • Primary: spontaneous onset with no known cause or trauma.
    • Secondary: associated with trauma, prolonged immobility, surgery or other pathology, such as sub-acromial pain (2).
  • It is characterised by fibroproliferative tissue fibrosis (formation of scar tissue, adhesions and capsular thickening) (2,3). 
  • Frozen shoulder has an incidence of 3-5% in the general population (4), which may be as high as 20% in individuals with diabetes (5).
  • Frozen shoulder often has a varying presentation, with evolution of symptoms over time. 
  • Typically, it is a self-limiting disease that resolves within 1-3 years, although 20-50% of patients may develop chronic symptoms (3).
  • Up to 6% of patients report severe symptoms >7 years after symptoms begin (6).
  • In up to 17% of cases, patient can have symptoms in the other shoulder within 5 years (2).

Risk factors (3)

  • Female (higher incidence compared to males)
  • 40–59-year-olds
  • Metabolic factors, such as diabetes, thyroid disorders & hyperlipidaemia
  • Preceding trauma
  • Prolonged immobilisation of the glenohumeral joint
  • Other comorbidities, such as cerebrovascular disease, coronary artery disease, neurological conditions, autoimmune conditions, ankylosing spondylitis & Dupuytren’s disease. 

Figure 4: Summary of clinic-based tests and characteristic clinical features

Community based assessment for frozen shoulder

  • Primary care services may opt to utilise the local skillsets of first contact practitioners, with regards to corticosteroid injections and rehabilitation, to reduce waiting times.
  • A multidisciplinary approach, with close links between MSK clinicians, Radiology, Orthopaedics and Pain services, can significantly improve patient outcomes and prognosis.  
  • Develop links between local shoulder orthopaedics teams for the early escalation of patients with rotator cuff tears following trauma. 
  • Shared decision making should be explored with patients, after counselling them on the natural history of resolution for frozen shoulder. 

Is there a role for imaging?

Currently, the European Society of Musculoskeletal Radiology does not recommend the use of imaging to diagnose frozen shoulder (7). 

Advantages Disadvantages
MRI 
  • Correlation of findings with clinical impairment 
  • Expensive
  • Limited availability
Ultrasound
  • Cost effective
  • Time efficient
  • Easy access
  • Dynamic capabilities with multiple scanning planes
  • Some studies have reported ultrasound (US) criteria for frozen shoulder
  • Reliant on clinician expertise and equipment used
  • Role in diagnosis of frozen shoulder has not yet been fully evaluated

Table 1: Imaging options for frozen shoulder (8,9)

Figure 5: MRI of a patient with frozen shoulder

Red arrow indicates pericapsular oedema in the axillary recess.

Although there are no existing diagnostic criteria for frozen shoulder, numerous studies have reported characteristic findings with MSK ultrasound. The presence of these findings, alongside a clinical history, can be useful in cases of diagnostic uncertainty.

The MSK ultrasound playbook for frozen shoulder 

Ultrasound findings Sensitivity Specificity
Coracohumeral ligament thickening 
> 0.7mm (8) 93.1 94.4
> 2.2mm (10) 77 91.8
> 3mm (11,12) 44.83-64.4 78.95-88.9
Increased soft tissue in the rotator interval (8,11,13)  71.1-97 92.5-100
Axillary pouch thickening (5) 100 98
> 2.0mm (14) 100 96
> 3.5mm (11) 93.3 66.7
> 4mm (5,10) 68.9-93.4 90.2-98
< 4mm but > 60% vs contralateral side (5) 6.6 98
Restricted external rotation of subscapularis 

(dynamic scanning) (5,8) 

72.6-86.2 92.8-100.0
Bounce sign (5) 41.5 100

Table 2: Characteristic ultrasound findings

Point of care ultrasound (POCUS) enables US clinicians to rapidly assess for concurrent conditions and key differential diagnoses, such as rotator cuff tears, tendinopathies or bursitis, when there is diagnostic uncertainty. 

POCUS also enables image-guided shoulder injections to be performed, which have shown to provide superior improvements in pain and shoulder functionality compared to blind injections (15). Ultrasound-guided hydro-distension and supra-scapular nerve block injections have also been shown to be effective in outpatients settings where expertise to deliver them are available (16,17). 

Suprascapular Nerve & Notch:

Watch video here.

Infraspinatus Tendon

Watch video here.

Videos courtesy of : https://www.orcaresource.com 

Post injection follow up; commence early rehabilitation to maximise the benefits of hydrodistension

Hydro-distension is a well-tolerated procedure and has a low risk of adverse events (18). It has shown to provide relief of symptoms in 93% of patients following their first hydro-distension procedure, with low rates of repeat interventions. To maximise the benefits of hydrodistension, an exercise programme should accompany the procedure. Self-directed, home exercise programmes following hydro-distension has shown to be as effective as supervised physiotherapy programmes (19). 

Suprascapular nerve – to block or not to block?

Pain physicians, Sport & Exercise Medicine physicians, radiologists and orthopaedic surgeons regularly perform suprascapular nerve blocks (SSNB) for analgesia due to the sensory innervation of the subacromial bursa, posterior glenohumeral joint capsule and acromioclavicular joint.  

A landmark technique or ultrasound guided technique can be used where the technical expertise is available. The aim of a SSNB is to improve the patient’s tolerance to hydrodistension, reduce pain during the procedure and after during physical therapy/ rehabilitation.   

Dose: 5mls of 1% Lidocaine or 0.5% Bupivacaine/Levobupivacaine +/- Depomedrone

Adjunctive therapy Mechanism of action Benefits
Hydrodistension (20–22)
  • Physical distension of the shoulder joint capsule by injecting 20-40ml of fluid (saline, steroids & local anaesthetics)
  • May decrease glycosaminoglycan concentration within the joint capsule, which reduces myofibroblast activity
  • Provides most rapid improvement of pain
  • A second hydrodistension can be considered in patients with persistent symptoms, after a 3-month period
Suprascapular nerve block (SSNB) (18)
  • Reduces pain by blocking the sensory nerve supply to the posterior joint capsule
  • May improve patient’s tolerability to hydrodistension

Table 3: Summary of the common adjunctive therapies

Figure 6: Summary of the post-treatment phase of the community based MSK pathway for frozen shoulder

Figure 7: Summary of what the community-based frozen shoulder pathways can offer

Conclusion

  • Frozen shoulder remains a clinical diagnosis based on a patient’s history and examination.
  • POCUS is typically used to exclude other causes of shoulder pain/stiffness, where there may be a clinical history (trauma or cuff tear) to suggest another diagnosis. 
  • Thickening of the coracohumeral ligament, increases in soft tissue in the rotator interval and axillary pouch thickening are characteristic ultrasound findings with good diagnostic accuracies. 
  • Suprascapular nerve blocks can be considered as an adjunct if the patient is unable to tolerate hydrodistension due to pain. 

 

Authors and Affiliations: Rifat Hassan, Lynsey Abbey Joslin, Peter Resteghini, Hozefa Dahodwala, Dr Sadiq Bhayani, Dr Imran Lasker, Dr Irfan Ahmed, Mr Niel Kang

Rifat Hassan 

Final Year Medical Student 

University of Southampton

Twitter @RifatHassan_

 

Lynsey Abbey Joslin

Medical Student 

University College London (UCL)

Twitter @AbbeyJoslin 

 

Peter Resteghini

Consultant Physiotherapist & Musculoskeletal Sonographer

Course Director for the Postgraduate Certificate in Musculoskeletal Ultrasound (University of East London)

Homerton Hospital 

@PeterResteghini

 

Hozefa Dahodwala 

Advanced Practitioner Physiotherapist & Musculoskeletal Sonographer

Connect Health, United Kingdom

Twitter @Hozefa_Physio

 

Dr Sadiq Bhayani

Consultant Pain Physician 

Cleveland Clinic Abu Dhabi, UAE 

Founder Pain Flix 

Co-Founder Gulf Pain School 

Special interest in Ultrasound Guided Pain & MSK Interventional Pain Management 

https://www.youtube.com/watch?v=aQSbzqoAmGU

Twitter @BhayaniSadiq

 

Dr Imran Lasker

Consultant Radiologist with Specialist interest in MSK

Mid & South Essex Foundation Trust

Twitter @DocLasker

Links to MSK/MRI courses: imranlasker.comradiologyseminars.comemergencyimaging.co.uk

 

Dr Irfan Ahmed 

Locum Consultant in Musculoskeletal, Sport & Exercise Medicine

Addenbrookes Hospital

Twitter @ExerciseIrfan

 

Mr Niel Kang

Consultant Trauma & Orthopaedic Surgeon

Cambridge University Hospitals NHS Trust

Affiliate Assistant Professor 

Clinical school of medicine, University of Cambridge

Education and Careers Committee

British Orthopaedic Association

Twitter @kangsta77

 

With thanks to:

Ultrasound video of the shoulder provided by Orca Resource & Peter Resteghini.

Orca Resource EdTech streaming platform provides a comprehensive series of high-quality videos for the medical industry including musculoskeletal ultrasound

https://www.orcaresource.com 

No relevant conflicts of interests or relevant disclosures declared by any of the authors.

 

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