Chronic subacromial bursitis (SAB) is a common clinical condition characterized by chronic shoulder pain with a painful arc of motion, which commonly occurs during abduction and sometimes during internal rotation of the shoulder. In addition, the extremes of all passive movements are painful. The range of motion (ROM) of the shoulder is usually not limited or is limited in a noncapsular pattern (mainly abduction and internal rotation) (27,31). All resisted movements are painless or equally painful, and there is also tenderness over the deltoid region. The diagnosis of SAB remains doubtful until it is confirmed by an infiltration with local anesthetic.
Although chronic SAB can be treated with rest, ice, and anti-inflammatory medications, the most effective treatment is a local injection or infiltration (multiple injections) with corticosteroids into the subacromial (or subdeltoid) bursa (27). Corticosteroid injections have been widely used to treat shoulder pain, irrespective of the underlying etiology, such as rotator cuff disease, bursitis, and adhesive capsulitis, with variable clinical effects (2,4,6,22,29). The injections can be performed by palpation (using anatomical landmarks to place the needle) or with ultrasound (US) guidance with visualization of the needle tip at the target location (33,34).
Traditionally, the injection treatment of SAB has been administered using the palpation-guided technique by palpating the acromion with the thumb and then sliding the needle under the acromion in a horizontal approach (27). However, because physicians performing palpation-guided injections are uncertain of the relationship between the inflamed bursa and the inserted needle tip, the effect of the injection is highly dependent on the physician’s skill and experience. Some studies have failed to show a positive effect of palpation-guided corticosteroid injections (18,21,36). Previous studies also showed that 29%–80% of subacromial injections reach the subacromial bursa or the subacromial space when a palpation-guided injection technique is used (13,15,17) and that a positive clinical outcome was associated with accurate needle placement (13). The injection of other structures (e.g., tendons and ligaments) resulted in tissue injury and increased pain scores (17). To increase injection accuracy and to avoid tissue injury, or for patients who fail to respond optimally to blind shoulder injections, consideration should be given to the use of imaging to help improve the accuracy of corticosteroid placement (13).
In the last few years, there has been tremendous growth in the use of US for guiding musculoskeletal aspiration and injection. The chief advantage of an US-guided intervention is the ability to use real-time dynamic imaging without ionizing radiation. Previous studies have demonstrated that US-guided injection ensures correct needle placement and delivery of the medicine to the target (15). However, whether the accuracy of needle placement has a significant impact on the clinical outcome is still controversial. A review article also showed no evidence that US-guided subacromial bursal injections improved long-term outcomes (16), whereas other studies have reported improved clinical outcomes with US-guided subacromial corticosteroid injections (15). These conflicting results may be due to critical limiting factors, such as the use of a control group with randomization, improper study design, incomplete data sets during follow-up, small sample size, or lack of or inadequate patient demographic information (11,20,32).
Although US-guided subacromial corticosteroid injection has shown some promising results in the treatment of patients with shoulder pain, its effect on chronic SAB remains controversial. The purpose of this study was to compare the efficacy of subacromial corticosteroid injection under US guidance with traditional palpation-guided subacromial injection in patients with chronic SAB. We hypothesized that the US-guided shoulder injection technique could achieve greater improvement in shoulder pain, ROM, functional ability, and quality of life compared with the palpation-guided injection technique.
PATIENTS AND METHODS
Eligible subjects met the following inclusion criteria: (a) shoulder pain for more than 1 month, (b) painful abduction with a visual analog scale (VAS) score for pain ≥ 4, (c) the presence of a painful arc of motion or pain at the mid- to terminal range of shoulder abduction or internal rotation and a soft end feel, (d) tenderness over the subacromial bursa, and (e) a reduction in pain of >40% on active shoulder abduction at the terminal range after the injection of 3 mL of 1% lidocaine into the subacromial bursa. The entrance site of injection was at 1–2 cm beneath the middle point of the lateral edge of the acromion, as described in the section on Subacromial bursa injection without US guidance. The exclusion criteria were as follows: (a) a history of uncontrolled chronic diseases, for example, malignant neoplasms, hypocoagulability, and infection; (b) previous surgery of the affected shoulder; (c) any evidence of a rotator cuff tear or tendinopathy, demonstrated by positive resistive tests or sonographic findings; (d) calcification of the rotator cuff, demonstrated by x-ray or sonographic findings; (e) the presence of arthritis, such as inflammatory arthritis (e.g., rheumatoid arthritis, seronegative spondyloarthropathy, and crystal-related arthropathy), osteoarthritis, frozen shoulder, subacromial spurs, or deformity of the acromion; (f) the presence of instability of the affected shoulder; (g) a previous fracture near the shoulder region; (h) the presence of cervical radiculopathy or myelopathy; and (i) having received a corticosteroid or hyaluronate subacromial or shoulder joint injection in the past 3 months.
This was a prospective, randomized, and single-blind study. From March 2010 through November 2011, patients with chronic SAB were recruited from the outpatient clinic of the Department of Physical Medicine and Rehabilitation at Shin Kong Wu Ho-Su Memorial Hospital. The study project and the consent form were approved by the hospital’s ethics committee. Randomization was performed after obtaining written informed consent and the baseline information. The patients were randomized into two treatment groups: group 1, US-guided subacromial (subdeltoid) corticosteroid injections (the US group); and group 2, traditional palpation-guided subacromial corticosteroid injections without US guidance (the PP group). The assignment scheme was generated using a table of computer-generated random numbers. Each patient was allocated to one of the treatment groups according to the randomization sequence. The outcome assessor was blinded to the treatment assignment, but the patients and the physician administering the injections were not blinded. In both groups, each subject received one injection during the study period. All of the injections were administered by a senior physician (L-F, H) who was a board-certified rheumatologist, physiatrist, and ultrasonographer in musculoskeletal medicine.
US-guided subacromial (subdeltoid) injection
We used the LOGIQ P5 (General Electronic Company, Milwaukee, WI) machine for ultrasonographic examinations and injection guidance. The probe, a 5- to 12-MHz linear array transducer, was used to assess the shoulders and to guide the injection needles. After the sterilization of the skin on the lateral side of the affected arm, a 21-gauge needle was inserted into the subdeltoid bursa under US guidance, and any effusion, if present, was aspirated. Then, 0.5 mL (5 mg·mL−1) of dexamethasone (Rinderon, Taiwan Shionogi) and 3 mL (10 mg·mL−1) of lidocaine hydrochloride (Xylocaine; AstraZeneca, London, UK) were injected into the subacromial bursa under US guidance (Fig. 1) (8,19,23).
Subacromial bursa injection without US guidance (palpation-guided injection technique)
We injected the subacromial bursa according to Cyriax’s method (27). We first localized the lateral edge of the acromion. Then, we asked the patient to relax the affected arm, and at 1–2 cm beneath the middle point of the lateral edge of the acromion, we inserted a 21-gauge needle medially and in a slightly cranial direction into the bursa. If the needle encounters resistance, either the coracoacromial ligament or the capsulotendinous structures have been contacted, and the needle position should be slightly adjusted.
The primary outcome measures were the VAS for pain and the active and passive ROM at 1 month after injection. The secondary outcome measures were the scores of the Shoulder Pain and Disability Index (SPADI), the Shoulder Disability Questionnaire (SDQ), and the 36-item Short-Form Health Survey (SF-36). All of the evaluations were performed by a blinded assessor who was a well-experienced physical therapist. The patients were evaluated before treatment and were reevaluated immediately, 1 wk, and 1 month after the injection for the VAS for pain and ROM measurements; the SPADI, SDQ, and SF-36 questionnaires were administered at baseline, 1 wk, and 1 month after the injection.
Demographic data, including age, gender, weight, height, and sports activities, were recorded at baseline. A history was taken from each patient concerning the duration of their complaint (in months). Concomitant diseases and the use of medications were also recorded.
Range of motion
The active and the passive ROM of the affected shoulder were measured using a goniometer under the guidelines of the American Academy of Orthopedic Surgeons (24). These measurements included abduction in the frontal plane, forward flexion, internal rotation, and external rotation with the arm at 0° of abduction.
Pain and disability
Shoulder pain and disability were measured using three questionnaires: the VAS for pain (28), the SPADI (7), and the SDQ (5,10). The VAS scores for pain were obtained using a 100-mm-long horizontal line, with 0 mm on the left, indicating no pain, and 100 mm on the right, indicating very severe pain. The SPADI is a self-administered questionnaire used to assess the pain and disability associated with shoulder diseases. It consists of 13 items that are divided into two subclasses, with five items for pain and eight items for disabilities. The total SPADI score, which ranges between 0 and 100, is calculated by averaging the scores from the pain and disabilities subclasses. The SDQ is a symptoms-related questionnaire containing 16 items describing common situations that may induce symptoms in patients with shoulder disorders. By responding yes, no, or not applicable, the final score is obtained by dividing the number of positively scored items by the total number of applicable items and then multiplying this number by 100, which results in a final score ranging between 0 (no disability) and 100 (the worst situation).
Quality of life
The SF-36 is a 36-item questionnaire that evaluates the quality of life (26,35). It is composed of eight subscales: physical functioning, physical role, bodily pain, general health, vitality, social functioning, emotional role, and mental health. Each subscale has a score range of 0–100, with a higher score indicating better health status.
Radiographs of the shoulder
Plain radiographs of the shoulder (including AP and lateral views) were obtained to exclude fractures, osteoarthritis, anatomical variants of the acromion, bone tumors, and osteonecrosis.
Sonography of the shoulder
The US of the shoulder was performed with a US machine using a multifrequency 5- to 12-MHz linear array probe (LOGIQ P5; General Electronic Company). After the US coracoacromial window was obtained, the biceps long head, subscapularis tendon, acromioclavicular joint, supraspinatus tendon, and infraspinatus tendon were examined sequentially. In addition, the subdeltoid bursa, the humeral head, and some parts of the glenoid labrum were also visualized.
Group differences in the demographic data were analyzed using a chi-square test for gender and exercise habits, and an independent t-test was used for age, weight, height, and disease duration. For the ROM outcome measurements, a 2 × 4, two-way mixed-model analysis of variance, which had one between-subject factor (group: US and PP) and one within-subject factor (evaluation time: pretreatment, immediately posttreatment, 1 wk posttreatment, and 1 month posttreatment), was performed. For the outcome measurements obtained from the SF-36, SDQ, and SPADI, a 2 × 3, two-way mixed-model analysis of variance, which had one between-subject factor (group: US and PP) and one within-subject factor (evaluation time: pretreatment, 1 wk posttreatment, and 1 month posttreatment), was performed. Pairwise comparisons between groups were performed using an independent t-test when a significant interaction was found; otherwise, the main effects were reported. When a time effect was found, a post hoc analysis was performed using a polynomial test to determine the trend (linear or quadratic). All significance levels were set at α = 0.05, and the Statistical Package for the Social Sciences (version 19.0; SPSS Inc., Chicago, IL) was used for all statistical analyses.
A total of 145 patients were recruited for the current study. Among them, 31 patients met the exclusion criteria and 18 patients were unwilling to sign the consent form. As a result, 48 subjects in the US group and 48 subjects in the PP group participated in this study (Fig. 2). Of these, 2 subjects in each group withdrew during the follow-up period due to reasons unrelated to the study. Thus, 46 subjects in each group completed the study. The baseline characteristics of these patients are listed in Table 1. No significant demographic or baseline measurement differences were found between the two groups (Table 1).
Range of motion
In both groups, both active and passive ROM improved linearly with increasing time after treatment (Fig. 3), as did the active ROM for flexion (F2,090 = 21.27, P < 0.001), abduction (F2,90 = 18.00, P < 0.001), external rotation (F2,90) = 17.01, P < 0.001), and internal rotation (F2,90 = 4.34, P < 0.001). In addition, significant linear increases in the passive ROM regarding flexion (F2,090) = 21.17, P < 0.001), abduction (F2,90 = 23.11, P < 0.001), external rotation (F2,90 = 17.71, P < 0.001), and internal rotation (F2,90 = 7.63, P < 0.001) were found for both groups as the postinjection time increased. In the group comparison, no significant group effects were found for any of the active ROM (Figs. 3A–3D) or the passive ROM (Figs. 3E and 3G–3H), except for passive abduction (Fig. 3F). Higher values of passive shoulder abduction were found in the US group than that in the PP group (F2,90 = 4.60, P = 0.03).
Pain and disability
Pain and disability decreased linearly with increasing time after treatment for both groups. The results of the VAS for pain and SDQ pain-related questionnaire (Table 2) indicated decreased symptoms with increased time after treatment for both groups. The SPADI results indicated that pain, disability, and the total score were significantly and linearly decreased with time for both groups (Table 2), suggesting that there were similar improvements in pain- and disability-associated shoulder disorders in the two groups. In the group comparison, no significant group effects were found for pain on the VAS, the SDQ, or the SPADI (Table 2).
Quality of life
Significantly increased scores for physical functioning, physical role, bodily pain, vitality, and social functioning were found in both groups with increasing time after treatment, whereas scores on the general health, emotional role, and mental health items remained statistically unchanged (Table 3). In the group comparison, significantly better scores for physical functioning and vitality were noted in the US group (Table 3).
Although subacromial corticosteroid injection has been used for a long time, the injection of corticosteroid into the subacromial–subdeltoid bursa using US guidance is a relatively new intervention for the management of SAB. The current study confirmed that subacromial corticosteroid injection, either with the palpation-guided method or with US guidance, was effective in the treatment of patients with chronic SAB, and US-guided injection yielded better results for passive shoulder abduction and physical functioning and vitality in SF-36 than palpation-guided injection method. The strengths of our study included a relatively large sample size, randomization of subjects, and comprehensive evaluations of pain, functional ability, and quality of life for a relatively long period compared with previous studies (8,22).
The diagnosis of chronic SAB was made mainly on the basis of clinical history and physical examination; plain x-ray and US played only a supporting role in the exclusion of subjects from this study. Plain x-ray can exclude arthritis or calcification of the shoulder, subacromial spurs, and anatomical variants of the acromion, whereas US was used for the detection of rotator cuff tears, joint degeneration, and calcification. Although thickening of the subacromial bursa or excessive fluid in the bursa could be detected on US examination, previously published studies in the literature contain no suitable definition for the diagnosis of SAB using US (25). Our physical examination was based mainly on Cyriax’s method of functional testing of the shoulder and cervical spine, but the Neer and Hawkins–Kennedy tests were also included. For confirmation of bursitis in our study, local anesthetic was injected into the subacromial bursa to relieve the pain. We excluded patients with rotator cuff lesions (degeneration, tear, or calcification), subacromial spurs, anatomical variants of the acromion, arthritis of the shoulder, bone tumors, and fractures because those conditions may require treatments other than corticosteroid injection. Exclusion was determined by physical examination, US, and plain x-ray of the shoulder. As the disease duration of most subjects recruited was more than 3 months, we believed that most of our patients were compatible with the diagnosis of chronic SAB, which has a different clinical picture than acute SAB. For the treatment of patients with chronic SAB without other related pathologies, subacromial corticosteroid injection or infiltration is strongly recommended (27).
Previous studies related to the benefit of US-guided injection showed contradictory results. For patients with SAB, Chen et al. (8) found that US-assisted subacromial bursa injection improved shoulder abduction at 1 wk, compared with the palpation-guided injection method. In a randomized study evaluating the response to subacromial or biceps tendon sheath corticosteroid injections, or both, Naredo et al. (22) demonstrated significantly improved VAS scores for pain and Shoulder Function Assessment scores in the US-guided group at 6 wk. In contrast, Hall and Buchbinder (16) found no evidence that US-guided subacromial bursal injections improved long-term outcomes; Rutten et al. (30) also found that palpation-guided injections into the subacromial bursa by an experienced clinician were as accurate as US-guided injections. Evaluation of the reported efficacy of corticosteroid injections remains difficult because many studies vary with regard to the indications for local injection, the corticosteroid and local anesthetic preparations used, and the postinjection regimens followed, including the use of a structured physical therapy program and nonsteroid anti-inflammatory drugs (1). The current study excluded all of these variables, any of which may influence observed outcomes. However, our study was basically consistent with those reported by Chen et al. (8) and Naredo et al. (22). According to various outcome measurements in this study, the benefits of US-guided injection were mainly seen in ROM (passive shoulder abduction) and quality of life.
The main advantage of a US-guided subacromial injection is to ensure the correct placement of the needle into the subacromial bursa and the accurate delivery of drugs, which may explain better clinical outcome in passive shoulder abduction and some items of SF-36. Because US beam cannot pass through the acromion, the target of US-guided subacromial injection is the bursa in the deltoid portion. With regard to palpation-guided subacromial injection, the needle tip is intendedly placed in the subacromial space, or in the subacromial portion of the bursa, not in the subdeltoid portion of the bursa, because the depth of the bursa in the deltoid portion is difficult to reach accurately without US guidance. During US-guided injection, we can clearly see the needle tip and distension of the subdeltoid bursa after injection (Fig. 1), which ensures that the whole injectates have been pushed into the subdeltoid bursa. During palpation-guided injection, however, we cannot visualize the presence of the needle tip and the injectates; the needle tip may not be in the subacromial bursa or some part of the injectates may have spread outside the subacromial bursa.
During palpation-guided injection, the needle end feel and the sensation during pushing the syringe are important. If it is too hard or too tight, the needle tip is probably in the acromioclavicular ligament; or in some rotator cuff tendon, the needle should be moved a little to get a soft needle end feel to ensure the needle tip is in the subacromial space or bursa. In our study, we used 21-gauge needles for injection in both groups because a smaller needle may not be visible during real-time US-guided injection. In clinical practice, a 25-gauge, 1.5- to 2-inch needle would be more suitable for injection with palpation-guided method.
Although the subacromial–subdeltoid bursa is contiguous in 95% of the normal population, adhesion of the bursa walls were occasionally found in the sonograms of our subjects, as described in the literature (27). In cases of bursa adhesion or a lack of communication between the subacromial bursa and the subdeltoid bursa, both corticosteroid and lidocaine may not reach all of the inflamed bursa if only one part of the bursa was injected. To overcome this problem, the infiltration technique (multiple injections) implemented at one site or even at both the subdeltoid and subacromial parts of the bursa was suggested by Cyriax (27). In this study, only one site injection was performed in each group; thus, we do not know whether using an infiltration technique or even multiple-site infiltration would produce better results.
The clinical response to the injection is mainly due to the anti-inflammatory effect of corticosteroid. Although immediate pain relief and increased ROM could be explained by the effect of lidocaine, the effects disappear in a few hours. The effectiveness at 1 wk and 1 month after injection was mostly due to the anti-inflammatory effect of the corticosteroid. In the past few years, the molecular pathophysiology of SAB has been studied. Gotoh et al. (14) found increased substance P in the subacromial bursa in patients with subacromial impingement syndrome, and Yanagisawa et al. (37) also demonstrated increased expression of vascular endothelial growth factor in patients with impingement. In addition, increased expression of several cytokine genes (TNF, IL-1α, IL-1β, and IL-6) was also demonstrated (3). All of these findings imply chronic inflammation and increased vascularity in the bursa, causing pain and bursa impingement during active or passive ROM of the shoulder.
Ekerberg et al. (12) found that gluteal corticosteroid injection has similar effect as US-guided corticosteroid subacromial–subdeltoid injection in the treatment of rotator cuff disorders. They concluded that local subacromial corticosteroid injection also had a systemic effect. In our study, 2.5 mg of dexamethasone subacromial injection produced a greater local effect than its systemic corticosteroid effect. Corticosteroid injection can reduce inflammation that occurs with chronic SAB, thus relieving the associated pain, which explains the increased ROM, pain relief, and improvement of SPADI, SDQ, and quality of life in our study.
In a systemic review of randomized control trials, Coombes et al. (9) demonstrated that corticosteroid injection produces short-term (4 wk, range 0–12) effect for the treatment of tendinopathy, but the effect was reverse at intermediate (26 wk, 13–26) or long term (52 wk or more). If the effect of corticosteroid injection for the tendinopathy could be applied to bursitis, the long-term effect of corticosteroid injection may be different from the short-term effect.
There are several limitations to the present study. First, we only performed follow-up assessments 1 month after the treatment; therefore, the long-term effects of the treatments are not known. Second, we did not include an untreated control group for ethical and practical reasons. However, because most of our subjects had experienced shoulder pain for longer than 3 months without signs of spontaneous improvement, we believed spontaneous recovery in a short period was unlikely. Third, we did not use MRI to screen the patients; thus, some labral lesions may have been missed in the sonography and plain x-ray of the shoulder. Fourth, as described above in this manuscript, even diagnostic block with local anesthetics for confirmation of SAB is not 100% accurate, the spread of local anesthetics to other tissues (e.g., rotator cuff or ligaments), cannot be excluded (but rotator cuff lesion could have been excluded during physical examination or ultrasonography).
In conclusion, this study demonstrated that subacromial corticosteroid injection, either with the palpation-guided method or under US guidance, was effective in reducing pain, increasing ROM, and improving SDQ, SPADI, and SF-36 scores in patients with chronic SAB. In addition, the US-guided injection technique yielded significant improvement in shoulder passive abduction and some items of the SF-36 compared with the blind injection technique. In a clinic without a US machine, we suggest palpation-guided injection of corticosteroid into the subacromial bursa for patients with chronic SAB; however, if palpation-guided injection fails, or a US machine is available, injection under US guidance is recommended.
The authors acknowledge the financial support provided by the Shin Kong Wu Ho-Su Memorial Hospital.
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.
The results of the present study do not constitute endorsement by the American College of Sports Medicine.
1. Akgün K, Birtane M, Akarırmak Ü. Is local subacromial corticosteroid injection beneficial in subacromial impingement syndrome? Clin Rheumatol
. 2004; 23 (6): 496–500.
2. Arroll B, Goodyear-Smith F. Corticosteroid injections for painful shoulder: a meta-analysis. Br J Gen Pract
. 2005; 55 (512): 224–8.
3. Blaine T, Kim Y, Voloshin I, et al. The molecular pathophysiology of subacromial bursitis in rotator cuff disease. J Shoulder Elbow Surg
. 2005; 14: 84S–9S.
4. Blair B, Roit AS, Cuomo F, Jarolem K, Zuckerman JD. Efficacy of injections of corticosteroids for subacromial impingement syndrome. J Bone Joint Surg Am
. 1996; 78 (11): 1685–9.
5. Bot M, Terwee CB, Windt M, Bouter LM, Dekker J, Vet W. Clinimetric evaluation of shoulder disability questionnaires: a systematic review of the literature. Ann Rheum Dis
. 2004; 63: 335–41.
6. Buchbinder R, Green S, Youd JM. Corticosteroid injections for shoulder pain. Cochrane Database Syst Rev
. 2003; (1): CD004016.
7. Carette S, Moffet H, Tardif J, et al. Intraarticular corticosteroids, supervised physiotherapy, or a combination of the two in the treatment of adhesive capsulitis of the shoulder: a placebo-controlled trial. Arthritis Rheum
. 2003; 48 (3): 829–38.
8. Chen MJL, Lew HL, Hsu TC, et al. Ultrasound-guided shoulder injections in the treatment of subacromial bursitis. Am J Phys Med Rehab
. 2006; 85 (1): 31–5.
9. Coombes BK, Bisset L, Vicenzino B. Efficacy and safety of corticosteroid injections and other injections for management of tendinopathy: a systemic review of randomised controlled triels. Lancet
. 2010; 376: 1751–67.
10. Daniëlle W, Geert H, Andrea FW, Bart WK, Walter D, Lex MB. The responsiveness of the Shoulder Disability Questionnaire. Ann Rheum Dis
. 1998; 57: 82–7.
11. del Cura JL, Torre I, Zabala R, Legorburu A. Sonographically guided percutaneous needle lavage in calcific tendinitis of the shoulder: short- and long-term results. Am J Roentgenol
. 2007; 189 (3): W128–W34.
12. Ekerberg OM, Bautz-Holter E, Tveita EK, Juel NG, Kvalheim S, Brox JI. Subacromial ultrasound guided or systemic steroid injection for rotator cuff disease: randomized double blind study. BMJ
. 2009; 338: a3112.
13. Eustace JA, Brophy DP, Gibney RP, Bresnihan B, FitzGerald O. Comparison of the accuracy of steroid placement with clinical outcome in patients with shoulder symptoms. Ann Rheum Dis
. 1997; 56 (1): 59–63.
14. Gotoh M, Hamada K, Yamakawa H, Inoue A, Fukuda H. Increased substance P in subacromial bursa and should pain in rotator cuff diseases. J Orthop Res
. 1998; 16: 618–21.
15. Gruson KI, Ruchelsman DE, Zuckerman JD. Subacromial corticosteroid injections. J Shoulder Elbow Surg
. 2008; 17 (1 Suppl): S118–30.
16. Hall S, Buchbinder R. Do imaging methods that guide needle placement improve outcome? Ann Rheum Dis
. 2004; 63 (9): 1007–8.
17. Henkus HE, Cobben LPJ, Coerkamp EG, Nelissen RGHH, van Arkel ERA. The accuracy of subacromial Injections: a prospective randomized magnetic resonance imaging study. Arthroscopy
. 2006; 22 (3): 277–82.
18. Kang MN, Rizio L, Prybicien M, Middlemas DA, Blacksin MF. The accuracy of subacromial corticosteroid injections: a comparison of multiple methods. J Shoulder Elbow Surg
. 2008; 17 (1 Suppl): S61–6.
19. Lim JB, Kim YK, Kim SW, Sung KW, Jung I, Lee C. Ultrasound guided shoulder joint injection through rotator cuff interval. Korean J Pain
. 2008; 21 (1): 57–61.
20. Maugars Y, Varin S, Gouin F, et al. Treatment of shoulder calcifications of the cuff: a controlled study. Joint Bone Spine
. 2009; 76 (4): 369–77.
21. McInerney JJ, Dias J, Durham S, Evans A. Randomised controlled trial of single, subacromial injection of methylprednisolone in patients with persistent, post-traumatic impingment of the shoulder. Emerg Med J
. 2003; 20 (3): 218–21.
22. Naredo E, Cabero F, Beneyto P, et al. A randomized comparative study of short term response to blind injection versus sonographic-guided injection of local corticosteroids in patients with painful shoulder. J Rheumatol
. 2004; 31 (2): 308–14.
23. Neethling-du Toit M, de Villiers R. Anterior approach v. posterior approach - ultrasound-guided shoulder arthrogram injection. S Afr J Radiol
. 2008; 12 (3): 60–2.
24. Norkin CC, White DJ. Measurement of Joint Motion: A Guide to Goniometry
. Philadelphia: F.A. Davis Co; 2003. p. 70–90.
25. O’Connor P, Rankine J, Gibbon W. Interobserver variation in sonography of the painful shoulder. J Clin Ultrasound
. 2005; 33: 53–6.
26. O’Kane JW, Jackins S, Sidles JA, Smith KL, Matsen FA. Simple home program for frozen shoulder to improve patients’ assessment of shoulder function and health status. J Am Board Fam Med
. 1999; 12(4): 270–7.
27. Ombregt L, Bisschop P, J ter Veer H. A System of Orthopaedic Medicine
. London: Churchill Livingstone; 2003. p. 333–5.
28. Ong K, Seymour R. Pain measurement of humans. Surgeon
. 2004; 2: 15–27.
29. Plafki C, Steffen R, Willburger RE, Wittenberg RH. Local anaesthetic injection with and without corticosteroids for subacromial impingement syndrome. Int Orthop
. 2000; 24 (1): 40–2.
30. Rutten MJ, Maresch BJ, Jager GJ, de Waal Malefijt MC. Injection of the subacromial–subdeltoid bursa: blind or ultrasound-guided? Acta Orthop
. 2007; 78 (2): 254–7.
31. Sahlstrand T, Save-Soderbergh J. Subacromial bursitis with loose bodies as a cause of refractory painful-arc syndrome. A case report. J Bone Joint Surg Am
. 1980; 62 (7): 1194–6.
32. Serafini G, Sconfienza LM, Lacelli F, Silvestri E, Aliprandi A, Sardanelli F. Rotator cuff calcific tendonitis: short-term and 10-year outcomes after two-needle US-guided percutaneous treatment-nonrandomized controlled trial. Radiology
. 2009; 252 (1): 157–64.
33. Skedros JG, Hunt KJ, Pitts TC. Variations in corticosteroid/anesthetic injections for painful shoulder conditions: comparisons among orthopaedic surgeons, rheumatologists, and physical medicine and primary-care physicians. BMC Musculoskelet Disord
. 2007; 8: 63.
34. Speed CA. Injection therapies for soft-tissue lesions. Best Pract Res Clin Rheumatol
. 2007; 21 (2): 333–47.
35. Ware JJ. The MOS 36-item Short-Form Health Survey (SF-36), I: conceptual framework and item selection. Med Care
. 1992; 30: 473–83.
36. Yamakado K. The targeting accuracy of subacromial injection to the shoulder: an arthrographic evaluation. Arthroscopy
. 2002; 18 (8): 887–91.
37. Yanagisawa K, Hamada K, Gotoh M, Tokunaga T, Oshika Y, Tomisawa M. Vascular endothelial cell growth factor (VEGF) expression in the subacromial bursa is increased in patients with impingement syndrome. J Ortho Res
. 2001; 19: 448–55.