Kamal Mezian; Ke-Vin Chang1.
1 National Taiwan University Hospital
Last Update: February 25, 2018.
Adhesive capsulitis (AC), is also known as frozen shoulder an insidious
painful condition of the shoulder persisting more than 3 months. This
inflammatory condition that causes fibrosis of the glenohumeral joint capsule
is accompanied by gradually progressive stiffness and significant restriction
of range of motion (typically external rotation). However, the patients may
develop symptoms suddenly and have a slow recovery phase. The recovery is
satisfying in most of the cases, even though this may take up to 2 to 3 years.
The etiology of frozen shoulder is not yet fully understood. However, some
plausible risk factors have been identified:
• Diabetes mellitus (with a prevalence up to 20%)
• Thyroid disorder
• Shoulder injury
• Dupuytren disease
• Parkinson disease
• Complex regional pain syndrome
Adhesive capsulitis occurs in up to 5%. Females are 4 times more often
affected than men, while the non-dominant shoulder is more prone to be
Frozen shoulder is usually described as fibrotic, inflammatory contracture of
the rotator interval, capsule, and ligaments. However, the development of AC
remains not fully understood. Although disagreements exist, the most
recognized pathology is cytokine-mediated synovial inflammation with
fibroblastic proliferation based on arthroscopic observations. Additional
findings include adhesions around the rotator interval caused by increased
collagen and nodular band formation.
The structure usually affected first is the coracohumeral ligament the roof of
the rotator cuff interval. Contraction of the coracohumeral ligament limits
external rotation of the arm, which is usually first affected in early AC. In
advanced stages, thickening and contraction of the glenohumeral joint
capsule develop, further limiting the range of motion in all directions.
The studies of histopathology for the glenohumeral capsule have confirmed a
significant increase in fibroblasts, myofibroblasts, and inflammatory cells,
like B-lymphocytes, mast cells, and macrophages.
History and Physical
Patients suffering from early AC usually present with a sudden onset of
unilateral anterior shoulder pain. The typical symptoms comprise passive and
active range of motion restriction, first affecting external rotation and later
abduction of the shoulder. In general, depending on the stage and severity,
the condition is self-limiting, interfering with activities of daily living, work,
and leisure activities. Functional impairments caused by frozen shoulder
consist of limited reaching, particularly during overhead (e.g., hanging
clothes) or to-the-side (e.g., fasten one's seat belt) activities. Patients also
suffer from restricted shoulder rotations, resulting in difficulties in personal
hygiene, clothing and brushing their hair. Another common concomitant
condition with frozen shoulder is neck pain, mostly derived from overuse of
cervical muscles to compensate the loss of shoulder motion.
The physical findings are essential for a frozen shoulder diagnosis, although
pain and stiffness make it difficult for patients to comply with a complete set
of physical examination.
Two physical examinations are commonly used for diagnosing AC, including
tests of combined motion, as touching the scapula from behind the neck and
from behind the back.
However, the most pathognomonic feature for AC is a loss of passive ROM.
Practically, in cases of significant restriction of passive ROM, an
examination of active motion can be skipped. Nevertheless, as an
undetectable limitation of shoulder motion may be present in the early stage,
AC diagnosis should be reconsidered in patients who present with a gradual
restriction of range of motion at follow-ups.
In general, patients with frozen shoulder usually demonstrate significant
restriction in active and passive range of motion, particularly in external
rotation and abduction movement. Restricted motion in every direction not
only indicates the presence of a developed frozen shoulder, but it may be a
“red flag” for possible underlying malignancy or fracture.
Frozen shoulder is a clinical diagnosis made by medical history, physical
examination, and imaging modalities (ruling out another condition, rather
than confirming the diagnosis of AC). No specific test (laboratory or
imaging) alone provides the definitive confirmation of the AC diagnosis.
Diagnostic imaging of AC can be challenging because as the findings based
on currently available methods (such as radiographs, ultrasound, plain
magnetic resonance imaging, and computed tomography) are usually
unremarkable. Imaging is therefore limited to ruling out concurrent
pathologies, like rotator cuff tendon tears and glenohumeral joint
osteoarthritis. The imaging tool mostly applied to patients with AC is high-
resolution musculoskeletal ultrasonography (MUS), which has emerged to be
the first line to scrutinize shoulder pathology. Nevertheless, until now, there
is lack of specific ultrasound findings for diagnosis of AC. To be more
comprehensive, several investigators reported thickening of the
coracohumeral ligament to be a sonographic characteristic in patients with
AC. Another commonly referred ultrasound finding is the presence of fluid
accumulation around the long head of the biceps tendon. Although biceps
peri-tendinous effusion is prevalent in shoulders with AC, it is specific to AC
because it might be a result of other shoulder pathology (e.g., rotator cuff
disorders or biceps tenosynovitis). Furthermore, ultrasound is less useful in
the pathology associated with instability or SLAP (superior labrum anterior
posterior) lesion. A plain radiograph is of limited diagnostic values in
patients with frozen shoulder. Nevertheless, it is reasonable to obtain routine
shoulder radiographs to rule out other etiologies (e.g., tumors,
acromioclavicular and glenohumeral osteoarthritis). MRI may show
thickening of the coracohumeral ligament and glenohumeral joint capsule.
MRI arthrography may show a volume reduction of the joint space.
The “lidocaine test” is subacromial injection test that may be helpful in
establishing the diagnosis in ambiguous clinical scenarios, to rule out
subacromial conditions. In patients with AC, passive movement limitation
persists after injection of local anesthetics into the subacromial space. On the
other hand, patients suffering from subacromial impingement syndrome (e.g.,
pathology of the rotator cuff or bursa) usually experience improved passive
range of motion after injection. The injection can easily be performed with
Treatment / Management
Despite the number of published literature on the AC, there is no consistent
consensus about management of AC. The majority of treatment options for
AC are non-operative and include pharmacological management and physical
Early Frozen Shoulder
An early stage of AC is often managed as subacromial pathology. The early
“freezing” AC mentioned above can be considered as inflammatory. On the
other hand, the inflammation becomes less accentuated in the later stages,
where ROM limitation is predominant, and inflammation-related pain is not
as much pronounced. In the light of above differences, we must consider the
disease stage when planning the treatment strategy. The correct recognition
of the clinical stage may help tailor treatment plans more specifically. The
aim of treatment in the “freezing” stage should focus on pain control,
reduction of inflammation and patient education. Initial treatment options for
adhesive capsulitis may include acetaminophen or NSAID. Although
evidence regarding NSAID for the treatment of frozen shoulder is limited,
they can be prescribed to provide short-term relief from the night pain if
present. However, in severe cases, opioid analgesics may be required.
Physical therapy is important for pain control and restoration of normal
shoulder mobility. Those comprise manual therapies based on soft tissue
mobilization and gentle stretching. Regarding physical modalities, no
particular agent has shown to be superior. The patient can be prescribed, e.g.,
therapeutic ultrasound, cryotherapy or transcutaneous electrical nerve
stimulation (TENS) unit. Physical therapy management should focus on
therapeutic exercise. Although not all patients can tolerate mobilization
exercise within the initial stage of the frozen shoulder due to severe pain, a
supervised therapeutic exercise should be conducted to slow down ROM
restriction. Furthermore, a home exercise program should be given to the
patients on a daily basis. In patients suffering from moderate to severe pain
who are not responsive to non-operative treatments, intra-articular injection
of corticosteroid should be considered. The injection should be performed
under ultrasonographic or fluoroscopic guidance to ensure the correct needle
placement. Last but not least, rehabilitation exercise should be prescribed
Developed Frozen Shoulder
After the inflammation-related painful period subsides, the condition
progresses to a “frozen” and subsequently into a “thawing” phases. Treatment
objectives in the advanced stages should focus on regaining ROM limitation.
The physical therapists should provide more intensive (compared, e.g., to
subacromial pathologies) mobilization exercise to restore joint mobility. In
patients who do not respond well to non-operative treatments, a more
invasive therapy should be considered. The addition of suprascapular nerve
or interscalene brachial plexus blockage may result in further improvement.
In patients with refractory cases of frozen shoulder who do not improve after
6 months of non-operative treatment, more aggressive treatments such as
capsular hydrodilatation (stretching the joint capsule by the saline injectate
pressure), manipulation under anesthesia (tearing of the contracted capsule),
and arthroscopic capsular release (particularly in the rotator interval) can be
Adhesive capsulitis, particularly in early (freezing) stage might be a
diagnostic challenge as it may mimic subacromial pathology and rotator cuff
tendinopathy. Presentations mentioned above may result in the delay in
diagnosis of AC in the early phases. Regarding shoulder impingement and
rotator cuff pathology, patients report predominantly pain with less
pronounced passive range of motion. However, several facets help to
distinguish frozen shoulder from other shoulder disorders. Regarding the
causes other than AC, patients often state lifting a heavy object or performing
repetitive overhead movements. In contrast, frozen shoulder patients usually
describe spontaneous onset without an apparent cause or a history of overuse
activity. Extra precaution should be paid in case of the history of malignancy.
Common conditions that may mimic early adhesive capsulitis:
• Subacromial pathology and rotator cuff tendinopathy
• Post-stroke shoulder subluxation
• Referred pain (cervical spine or malignancy, e.g., Pancoast tumor)
Later in the course of frozen shoulder, as severe restriction of motion comes
to predominate, the diagnosis becomes more apparent. However,
glenohumeral joint arthritis should also be considered, which can be ruled out
by free shoulder movement following lidocaine injection to the glenohumeral
Age of onset provides additional clues to diagnose AC. Frozen shoulder is
unlikely in patients younger than 40 years of age, and patients older than 70
are more likely to develop rotator cuff tears or glenohumeral osteoarthritis
instead of AC.
Gradual restriction of passive shoulder motion characterizes a natural course
of AC. The development is commonly described as progressing through 3
overlapping phases (4 stages classification can also be found in the
literature). However, from a practical point of view, we recommended
using 2-stage scheme: early and developed frozen shoulder.
1. Freezing (2 to 9 months): Early
2. Frozen (4 to 12 months): Developed
3. Thawn (12 to 42 months): Developed
An initial, painful phase with predominant pain that is worse at night, with
gradually increased glenohumeral joint ROM restriction.
The second phase with stiffness and persisted glenohumeral joint motion
limitation, but with less pain than that at the “Freezing” stage.
The third (recovery) phase with the gradual return of range of motion.
The duration of AC is from 1 to 3.5 years with a mean of 30 months. In about
15% of patients, the contra-lateral shoulder becomes affected within 5 years.
Pearls and Other Issues
Considering the diagnostic accuracy of frozen shoulder, researchers should
keep investigating the pathomechanism of AC. Some studies have recently
reported the application of contrast-enhanced ultrasonography in the
diagnosis of frozen shoulder. Application of the microbubble-based
ultrasound contrast agents (increasing a liquid substance echogenicity) in
musculoskeletal medicine has already been adopted for selected indications.
Looking ahead, the utility of contrast agents in a frozen shoulder diagnosis
seems to be promising particularly in ambiguous cases.
To access free multiple choice questions on this topic, click here.
1. Kanbe K, Inoue K, Inoue Y, Chen Q. Inducement of mitogen-activated
protein kinases in frozen shoulders. J Orthop Sci. 2009 Jan;14(1):56-
61. [PMC free article] [PubMed]
2. Chang KV, Lew HL, Wang TG, Chen WS. Use of contrast-enhanced
ultrasonography in musculoskeletal medicine. Am J Phys Med
Rehabil. 2012 May;91(5):449-57. [PubMed]
Reeves B. The natural history of the frozen shoulder syndrome. Scand.
J. Rheumatol. 1975;4(4):193-6. [PubMed]
Zuckerman JD, Rokito A. Frozen shoulder: a consensus definition. J
Shoulder Elbow Surg. 2011 Mar;20(2):322-5. [PubMed]
Song A, Higgins LD, Newman J, Jain NB. Glenohumeral corticosteroid
injections in adhesive capsulitis: a systematic search and review. PM
R. 2014 Dec;6(12):1143-56.[PMC free article] [PubMed]
Jain TK, Sharma NK. The effectiveness of physiotherapeutic
interventions in treatment of frozen shoulder/adhesive capsulitis: a
systematic review. J Back Musculoskelet Rehabil. 2014;27(3):247-
Özçakar L, Kara M, Chang KV, Tekin L, Hung CY, Ulaülı AM, Wu
CH, Tok F, Hsiao MY, Akkaya N, Wang TG, Çarli AB, Chen WS, De
Muynck M. EURO-MUSCULUS/USPRM Basic Scanning Protocols
for shoulder. Eur J Phys Rehabil Med. 2015 Aug;51(4):491-
Harris G, Bou-Haidar P, Harris C. Adhesive capsulitis: review of
imaging and treatment. J Med Imaging Radiat Oncol. 2013
Ozaki J, Nakagawa Y, Sakurai G, Tamai S. Recalcitrant chronic
adhesive capsulitis of the shoulder. Role of contracture of the
coracohumeral ligament and rotator interval in pathogenesis and
treatment. J Bone Joint Surg Am. 1989 Dec;71(10):1511-5. [PubMed]
Maund E, Craig D, Suekarran S, Neilson A, Wright K, Brealey S,
Dennis L, Goodchild L, Hanchard N, Rangan A, Richardson G,
Robertson J, McDaid C. Management of frozen shoulder: a systematic
review and cost-effectiveness analysis. Health Technol
Assess. 2012;16(11):1-264. [PMC free article] [PubMed]
Copyright © 2018, StatPearls Publishing LLC.