2.4 Shoulder - Adhesive Capsulitis

2.4.1 Definition and epidemiology

Definition

Adhesive capsulitis is characterised by pain and restricted range of motion at the glenohumeral joint. Pathophysiological signs include thickening of the synovial capsule, adhesions in the subacromial or subdeltoid bursa, adhesions to the biceps tendon, and obliteration of the axillary fold secondary to adhesions (Manske & Prohaska, 2008). Complete resolution of symptoms with minimal or conservative intervention is not achieved in the majority of patients (Wong et al, 2017; Hand et al, 2008). The Quick reference summary of Practice guidelines from the Orthopedic Section of the American Physical Therapy Association Hanchard et al (2012) recommends adhesive capsulitis be referred to as 'pain-predominant' or 'stiffness-predominant', as their responses to therapy may differ. Adhesive capsulitis can be characterised into four overall stages, as described by Hannafin & Chiaia (2000):

Stage 1:

• Symptom duration: 0-3mo
• Pain with active and passive ROM
• Limitation of forward flexion, abduction, internal rotation, external rotation
• Examination under anaesthesia: normal or minimal loss of ROM
• Arthroscopy: diffuse glenohumeral synovitis, often most pronounced in the anterosuperior capsule
• Pathologic changes: Hypertrophic, hypervascular synovitis, rare inflammatory cell infiltrates, normal underlying capsule

Stage 2: 'Freezing Stage'

• Symptom duration: 3-9mo
• Chronic pain with active and passive ROM
• Significant limitation of forward flexion, abduction, internal rotation, external rotation
• Examination under anaesthesia: ROM essentially identical to awake ROM
• Arthroscopy: Diffuse, pedunculated synovitis (tight capsule with rubbery or dense feel on insertion of arthroscope)
• Pathologic changes: Hypertrophic, hypervascular synovitis with perivascular and subsynovial scar, fibroplasia and scar formation in the underlying capsule

Stage 3: 'Frozen stage'

• Symptom duration: 9-15mo
• Minimal pain except at end ROM
• Significant limitation of ROM with rigid 'end feel'
• Examination under anaesthesia: identical to awake ROM
• Arthroscopy: No hypervascularity seen, remnants of fibrotic synovium can be seen. the capsule feels thick in insertion of the arthroscope and there is a diminished capsular volume
• Pathologic changes: 'Burned out' synovitis without significant hypertrophy or hypervascularity. Underlying capsule shows dense scar formation

Stage 4: 'Thawing phase'

• Symptom duration: 15-24mo
• Minimal pain
• Progressive improvement in ROM

Epidemiology

Adhesive capsulitis has an incidence of 3–5% in the general population and up to 20% in those with diabetes. It is more common in females than males, and is most common in patients in their 5th to 7th decades of life (Manske & Prohaska, 2008). In an outpatient clinic, adhesive capsulitis represented 13.5% of shoulder disorders in a sample of 1001 patients (Malavolta et al, 2017). This diagnosis was second in incidence only to rotator cuff tendinopathy.

2.4.2 Treatment overview

Physiotherapy

Physiotherapy is performed in an attempt to restore range of motion. The specific components of treatment protocols vary, but most involve passive and accessory mobilisation towards the limit of the patient's ROM. The mechanism of action may include mechanical breakage of adhesions, collagen realignment, increasing fibre glide, and neurophysiological alterations involving stimulation of peripheral mechanoreceptors and inhibition of nociceptors (Ibrahim et al. 2014).

Corticosteroid injections

Corticosteroid injections are performed in order to address the inflammatory component of adhesive capsulitis. Typically, a single dose of corticosteroid is injected into the joint space of the affected shoulder (Uppal et al, 2015). Injections may be glenohumeral or subacromial in location.

Nonsteroidal Anti-inflammatory Drugs (NSAIDs)

Oral NSAIDs may be prescribed to address the inflammation and pain associated with adhesive capsulitis, in particular during early stages or in mild cases.

Hydrodilatation (brisement)

Hydrodilatation involves injection of a substantial volume of local anaesthetic into the shoulder capsule, in order to distend the shoulder capsule and break the adhesions which are limiting movement (Uppal et al, 2015). Additives such as corticosteroids may also be included in the hydrodilatation fluid.

Manipulation under anaesthesia

Manipulation under anaesthesia involves stretching the shoulder capsule beyond the patient's pain-free range of motion in flexion, abduction, and external rotation if needed (Uppal et al, 2015). This procedure works via mechanical disruption of adhesions while the patient is anaesthetised and therefore unable to experience pain . The procedure carries some risk of iatrogenic injury of structures such as the humerus, rotator cuff, and other tissues. For the purposes of this registry, use of MUA will be primarily restricted to a small number of early-stage cases in which disruption can be achieved without the use of force.

Arthroscopic Capsular Release (capsulectomy)

There is no consensus regarding the extent of capsular release and which structures should be involved in release (Georgiannos et al, 2017). For this registry capsulectomy will typically involve visualisation via three arthroscopic portals, with rotator interval release performed via an incision of the anterior capsule with a radiofrequency probe in the 1.00 to 5.30 position. If range of motion is not equal following this release, a limited posterior capsule release will also be performed via reversal of the arthroscopic view.

2.4.3 Treatment Outcomes Summary

Outcomes commonly reported in the literature generally encompass measures of pain, function/disability, and active and/or passive ROM (Figure 2.3.1).

Conservative Interventions

There is moderate evidence for the use of exercise and physical therapy, and/or low level laser therapy for the management of adhesive capsulitis (Hawk et al, 2017). A recent Cochrane review reported that corticosteroid injection alone may be superior to manual therapy for short-term pain relief (Page et al, 2014). However, the beneficial effect of steroid injections for pain appear to be small and short lived, and may not be superior to NSAIDS (Buchbinder et al, 2003; Wang et al, 2017). Passive and active ROM may be superior than the alternatives after intra-articular corticosteroid injection (Wang et al, 2017). Another systematic review/meta-analysis of recent RCTs concluded that physiotherapy and corticosteroids were roughly equivalent in safety and efficacy, although this conclusion was based on studies with high heterogeneity (Sun et al, 2016). Overall, the evidence regarding effectiveness of conservative therapies for adhesive capsulitis is of low quality and high heterogeneity (Longo et al, 2018).

Hydrodilatation/brisement

In 2008, the Cochrane Review Group concluded that there was some evidence that arthrographic capsular distention (ie. hydrodilatation) provided short term benefits in pain and function (Buchbinder et al, 2008). It was not clear whether there were any benefits to addition of agents such as steroids to the dilatation fluid.

Manipulation Under Anaesthesia

Improvements in range of motion following MUA are similar to those seen following capsular release, although were slightly lower for abduction (median of combined study means 83 v 89 degrees) and external rotation at side (40 vs 47 degrees) (Grant et al, 2013). This systematic review found no major difference in median change in Constant score overall (47 vs 50), but when scaled relative to age and gender MUA was inferior to arthroscopic capsular release for this outcome. However, this was based on a single study with a small sample size (<50).

Arthroscopic Capsular Release (capsulectomy)

Rill and colleagues (2011) reported that improvements in forward elevation and external rotation were greater for patients undergoing surgery than those allocated to a multimodal nonoperative management protocol. However, improvements in the Simple Shoulder Test, a general patient-reported measure of function, were not significantly different between groups. Given patients with greater impairments and treatment-resistant disease are more likely to undergo surgery, it is difficult to retrospectively compare surgical and nonsurgical methodologies. Grant, Schroeder, Miller & Carpenter (2013) compared the literature available for manipulation under anaesthesia to capsular release procedures, and found only small differences in the median changes in abduction, flexion, and external rotation range of motion (ROM), and final Constant scores.

2.4.4 Summary and gap

• Although a number of strong outcome modifiers (such as diabetes) have been identified, the quality of the evidence available is too low to make recommendations regarding treatments for specific patient groups.
• There is a need for additional investigation into patient-specific factors affecting recovery from adhesive capsulitis, whether treated with surgery or physical therapy.

2.4.5 Cohort aims and hypotheses

In patients with adhesive capsulitis undergoing capsular release, manipulation under anaesthesia OR nonoperative management, what are the patient, pathology and management factors associated with treatment success/failure, and the appearance of adverse events, at up to two years post-intervention?

2.4.6 Cohort inclusion/exclusion criteria

Inclusion Criteria

• Diagnosed with Adhesive Capsulitis
• Undergoing treatment by primary investigator/orthopaedic consultant surgeon.
• Consenting to being part of PRULO

Exclusion Criteria

• Patient-reported outcomes: Clinically diagnosed mental/neurological illness (indicated on GP referral, or identified through secondary referral to psychiatric/neurological specialist) that precludes retrieval of patient feedback via interview, paper or electronic questionnaire (e.g., schizophrenia, dementia, Alzheimer's Disease, personality disorder).
• Revocation of consent for research use of personal data.

2.4.8 Cohort outcome measures

2.4.9 Cohort secondary outcome measures

Functional Biomechanics

Functional biomechanics will be determined by range of motion outcomes, including:

• Forward elevation;
• External rotation at 0;
• Abduction;
• Internal rotation at 0

Active range of motion of the shoulder (glenohumeral + scapulothoracic) will be assessed with the patient (sitting, standing) with the scapula unrestrained. Testing position will be standardised (recorded at least) as per the recommendations of Sabari et al. (1998). The patient will be asked to actively move their arm in abduction, forward flexion (abduction + flexion), as well as internal and external rotation with the humerus abducted to 90deg, without assistance from the examiner. A goniometer (baseline goniometer, manufacturer, country) with two adjustable overlapping arms, marked at 1deg increments, will be applied to the humerus (one arm) and to the upper torso at the end of the movement.

Complications and re-operations

Complications and re-operations are to be logged in the research database . A list of available complications can be found below.

Complication recording: Complications are recorded in the research database within the History, Surgeon Exam, F/Up and Complications window, in the Complications & Outcomes tab in Socrates as shown in Figure 2.4.9b.

Re-operation recording: If complications were severe enough to warrant re-operation, this must also be recorded in Socrates, with the date. An 'additional procedure' must be added here too with fields completed as shown in Figure 2.4.9c.

2.4.10 Statistical analysis plan

Background

Here the pre-determined statistical analysis plan for the Adhesive Capsulitis cohort is described, which was finalized prior to any data analysis and to which the investigators will adhere in future analyses. The statistical analysis plan was completed and approved by the registry steering committee on [insert date]. Prospective participant recruitment was commenced [insert date] and following data integrity checks (as per Section 3 of this document), the cohort dataset (including retrospective data prior to relaunch) will be locked on an annual basis and the statistical analysis as specified below will be performed.

Analysis Objectives/Questions

The analysis plan is derived directly from the cohort questions listed above.

Design

The adhesive capsulitis cohort analysis is a non-randomised observational study with census sampling (all patients presenting to the registry sites are included). Consecutive patients from the community seeking care for adhesive capsulitis following primary care referral will be screened by the participating consultant / orthopaedic surgeon for eligibility into the analysis.

Patient inclusion/exclusion

Alterations from cohort criteria: No

Treatment allocation

Patients will be allocated to a treatment pathway (surgery, non-surgical management, observation-only) as per the consultant surgeon’s clinical judgement and shared decision-making with the patient.

Sample Size

Sample size calculations were based upon a rule of thumb of 10 failure events per variable entered into the model (Vittinghoff and McCulloch 2007), assuming a failure rate of 10%. A sample size of 330 patients will have 80% power to detect a significant effect for 3 variables, allowing for up to 10% cohort protocol non-compliance and a two-sided alpha of 0.05. The failure rate is estimated from Smith, Hamer & Bunker (2014) which described clinical outcomes after arthroscopic capsular release in a series of 135 patients.

Preliminaries

The flow of patients through entry into the cohort and analysis will be displayed in a flow diagram as per STROBE guidelines (Strengthening The Reporting of Observational Studies in Epidemiology) (Figure 6) (Vandenbroucke et al. 2007). The number of exclusions and loss to followup will be noted from screening, data collection and analysis phases.

Data collection and follow-up

As per registry methods. Approval is also sought to invite patients who have not previously consented to participate in research to return patient reported outcome measures for the purposes of this study.

Variations from Cohort core dataset: No

Data Integrity

Initial statistical analysis will include examining data consistency and examining outliers in more detail. Where outliers in patient reported outcomes, surgical or clinical information are identified, source material will be examined and transcription errors rectified. Where the source material contains an outlier value, a decision will be made regarding the validity of the value. This will be reported in the published results and the datum excluded from further analysis if required.

As per Section 3 - quality management

Handling missing data

Missing data will be identified during the initial data quality assessment. Missing data identified in the electronic registry database will be investigated in the original source material where available. In patients with missing data who are eligible for follow-up, attempts will be made to contact the patient (mail and phone) to complete patient-reported outcomes. When the number of patients required to achieve 80% follow up at a minimum of 1 year has been achieved, missing data rates will be reported.

Analyse randomness of missing data

Variables

As per cohort core dataset

Outcomes

The proportion of patients labelled as “ongoing” in surgical status, having met the criteria for surgical success.

Surgery/management

As per cohort core dataset

Demographics and baseline characteristics

As per cohort core dataset

Analyses

Principles (incl. blinding)

Randomisation not applied to the analyses. Analyses will be performed with de-identified data (single-sided blinding)

Outlier analysis and normality will be assessed prior to a descriptive analysis of patient-reported outcomes using appropriate measures of central tendency (mean, median) and variability (95% confidence intervals). Patient-reported outcomes will be summarised using descriptive statistics as appropriate to data type (continuous, categorical). Binary logistic regression will be used to determine the association of demographic, anatomical, pathology and management factors to surgical success at a minimum of 1 year follow up.