Frozen Shoulder? How Hydrodilatation Can Restore Your Mobility

The condition typically progresses through three overlapping phases. 

1. The freezing phase is dominated by pain, often severe and frequently worse at night, with progressively worsening stiffness developing over weeks to months [6]. 
2. The frozen phase sees pain begin to ease, but stiffness reaches its maximum, with range of motion substantially reduced across all planes. 
3. The thawing phase involves a gradual, often slow, return of movement as the capsule loosens over time [6][7].

The cause of adhesive capsulitis is not fully understood, but it is more common in women than men, most frequently presents between the ages of 40 and 60, and has a well-established association with diabetes mellitus, thyroid dysfunction, cardiovascular disease and prolonged immobility following shoulder injury or surgery [2][8]. People with diabetes are not only at higher risk of developing frozen shoulder but tend to experience a more severe course and a slower recovery, making early intervention particularly important in this group [2][3].

Why Waiting Is Not Always the Answer

The conventional advice that frozen shoulder will eventually resolve on its own is technically accurate for many patients, but it obscures the scale of what waiting actually involves. Studies looking at patients managed conservatively have reported that full recovery can take anywhere from one to four years, and that a meaningful proportion of patients continue to experience some residual stiffness or pain beyond that period [9].

During the intervening months and years, frozen shoulder has a significant burden on daily life. Disrupted sleep is among the most commonly reported consequences, with many patients unable to lie on the affected side or find any comfortable sleeping position during the freezing and frozen phases [6]. Occupational impact is also considerable, with research published in the Journal of Shoulder and Elbow Surgery finding that frozen shoulder was associated with significant work absence and reduced productivity, particularly in roles requiring overhead activity or manual dexterity [10].

For people with diabetes, the case for active intervention rather than watchful waiting is particularly strong. A systematic review published in Diabetes Care found that diabetic patients with frozen shoulder had significantly longer recovery times, greater functional limitation and poorer outcomes with conservative management compared to non-diabetic patients, and were more likely to require procedural intervention to achieve satisfactory recovery [3][8]. The question for most patients is therefore not whether they should seek treatment, but which treatment is most likely to deliver meaningful improvement in the shortest time with the least risk.

What Is Hydrodilatation

Hydrodilatation, also known as distension arthrography or hydrodistension, is a minimally invasive procedure that treats frozen shoulder by injecting a carefully controlled volume of fluid, typically a combination of saline, corticosteroid and local anaesthetic, directly into the shoulder joint capsule under imaging guidance [11]. The fluid distends the contracted capsule, stretching and in some cases rupturing the fibrous adhesions that have formed within it, thereby increasing joint volume and restoring range of motion [5][11]. 

The corticosteroid component reduces inflammation within the joint, while the local anaesthetic provides immediate pain relief and makes the procedure well-tolerated. The entire procedure is performed under ultrasound or fluoroscopic guidance to ensure precise needle placement and accurate fluid delivery into the joint space [12]. The procedure is performed as an outpatient treatment, typically takes between 15 and 30 minutes, and requires no general anaesthetic or hospital admission. 

Most patients can return home shortly afterwards and are encouraged to begin gentle mobilisation exercises the same day to capitalise on the increased joint volume achieved during the procedure [13].

What the Evidence Shows

The evidence base for hydrodilatation in frozen shoulder is well established and continues to grow, with multiple randomised controlled trials and systematic reviews supporting its efficacy across all phases of the condition. A landmark randomised controlled trial published in the British Medical Journal compared hydrodilatation with placebo injection in patients with frozen shoulder and found that those receiving hydrodilatation demonstrated significantly greater improvements in pain, range of motion and shoulder function at six weeks and at six months, with the benefits maintained at long-term follow-up [14].

Additionally, a systematic review and meta-analysis published in the British Journal of Sports Medicine found that hydrodilatation combined with corticosteroid produced significantly greater improvements in pain and function compared with corticosteroid injection alone, physiotherapy alone or placebo [15]. In fact, a Cochrane review of interventions for frozen shoulder concluded that hydrodilatation with corticosteroid provided clinically meaningful short-term improvements in pain and function, and recommended it as an effective treatment option for patients who had not achieved adequate relief from initial conservative management [16].

A prospective study published in Skeletal Radiology found that ultrasound-guided hydrodilatation produced successful capsular distension in over 90% of procedures, with significant improvements in range of motion observed at four weeks in the majority of patients, and that outcomes were further improved when the procedure was combined with a structured physiotherapy programme commencing shortly after the injection [12][15].

Who Is Most Likely to Benefit

Hydrodilatation is most effective when performed at the right stage of the condition and in appropriately selected patients. 

Treatment is considered when a patient:

1. Has a confirmed diagnosis of adhesive capsulitis
2. Has experienced symptoms for at least six to eight weeks
3. Has not achieved adequate relief from initial conservative management including physiotherapy, oral anti-inflammatory medication and standard corticosteroid injection [11][13].

Patients in the freezing and early frozen phases tend to achieve the best outcomes, as the capsule at this stage retains sufficient elasticity to respond well to distension [6][15]. That said, patients in the frozen phase can also benefit meaningfully, particularly where pain and stiffness are significantly affecting daily function and sleep. People with diabetes represent a group in whom hydrodilatation has particular value, given the poorer outcomes associated with conservative management in this population and the evidence supporting procedural intervention as a more reliable route to recovery [3][8]. 

Patients who have previously undergone corticosteroid injection alone without achieving adequate improvement may also find that hydrodilatation delivers the additional mechanical benefit needed to restore movement. Hydrodilatation is generally not recommended as a first-line treatment before conservative measures have been tried, and is not appropriate in patients with active shoulder infection, recent shoulder surgery or certain structural abnormalities that would be better addressed through alternative means [11]. A thorough clinical assessment before the procedure is essential to confirm the diagnosis, exclude other causes of shoulder pain and stiffness, and ensure the treatment plan is appropriately tailored to the individual.

What to Expect from Treatment

For patients considering hydrodilatation, understanding what the experience involves from assessment through to recovery helps to manage expectations and prepare for the process. The clinical assessment prior to the procedure will include a detailed history of symptoms, physical examination of the shoulder and a review of any relevant imaging. Where the diagnosis of adhesive capsulitis is confirmed and hydrodilatation is agreed as an appropriate treatment, the procedure is scheduled as an outpatient appointment [1][11].

On the day, the shoulder is prepared and local anaesthetic is administered into the skin and underlying tissue before the needle is introduced into the joint space under ultrasound guidance. The fluid mixture is then injected slowly into the joint. Patients typically feel a sensation of pressure and stretch during the injection as the capsule distends, which can be briefly uncomfortable but is well tolerated by the majority [12][13].

Most patients notice some immediate improvement in range of motion following the procedure, reflecting the mechanical effect of capsular distension. Pain levels in the first 24 to 48 hours may temporarily increase as the joint responds to the procedure, before improving as the corticosteroid takes effect over the following days [13][15]. Physiotherapy commencing within a few days of the procedure plays an important role in consolidating and extending the gains in range of motion achieved through hydrodilatation. Research has consistently shown that outcomes are significantly better when the procedure is followed by a structured, progressive exercise programme compared with hydrodilatation alone [15].  Patients are typically reviewed at four to six weeks to assess progress and determine whether any further treatment is needed.