Adhesive capsulitis is a common cause of shoulder pain and disability. It is characterized by spontaneous onset of shoulder pain accompanied by progressive limitation of both active and passive glenohumeral movement (1). The pathophysiology of idiopathic adhesive capsulitis is poorly understood (2). Most authors have reported various degrees of inflammatory changes in the synovial membrane. Adhesions between the shoulder capsule and the humeral head have been noted by some (3), but not all (4, 5), authors. The optimum management of adhesive capsulitis has been the subject of great debate, particularly since the condition tends to resolve spontaneously over months to years (6–8). Intraarticular corticosteroid injections and/or physiotherapy programs combining exercise, physical agents, and mobilization are the 2 most common treatment options used in patients with adhesive capsulitis (9–17). However, clear evidence of the efficacy of either or both of these options in improving pain and function and in changing the natural history of adhesive capsulitis is lacking (18). We conducted a controlled trial to compare the efficacy of a single intraarticular corticosteroid injection, a supervised physiotherapy program, the combination of intraarticular corticosteroid and supervised physiotherapy, and placebo in patients with adhesive capsulitis who were also taught a simple home exercise program.
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The results of this trial indicate that a single intraarticular injection of corticosteroid administered under fluoroscopic guidance, coupled with a simple home exercise program, is superior to a 12-session supervised physiotherapy program in improving shoulder pain and function at 6 weeks in patients with adhesive capsulitis of the shoulder. When given alone, supervised physiotherapy using standardized modalities, including mobilization techniques, active, passive, and auto-assisted range of motion exercises, and physical agents did not result in any significant advantage compared with placebo. Supervised physiotherapy given in conjunction with corticosteroid injection provided clinically but not statistically greater improvement in shoulder pain and function at 6 weeks compared with the corticosteroid injection alone and resulted in faster improvement in shoulder ROM.
Our results confirm those reported by van der Windt et al showing that the beneficial effects of corticosteroid injection are superior to those of a supervised physiotherapy program (17). In their pragmatic randomized trial conducted in a primary care setting with patients who had stiff and painful shoulders, they demonstrated treatment success (defined as complete recovery or much improvement) at 7 weeks in 77% of patients treated with corticosteroid injections (average of 2.2 injections per patient), compared with 46% of patients treated with physiotherapy (difference between groups 31% [95% confidence interval 14–48%]). However, in the absence of a placebo group, they could not comment on the efficacy of physiotherapy alone. In the current study, we did not observe any significant difference in the degree of improvement between the physiotherapy and placebo groups for any of the outcome measures at any of the 4 followup evaluations, except for the range of shoulder flexion at 3 months. However, our study had sufficient power only to detect a difference of ≥20 points on the total SPADI score. Therefore, the possibility of a smaller but still clinically significant difference favoring physiotherapy cannot be ruled out.
With time, the differences between the 2 groups that received the corticosteroid injection and the 2 groups that did not became smaller, and by 12 months after enrollment, all 4 groups had achieved the same degree of improvement with respect to shoulder pain and disability. This included the placebo group, in which the mean ± SD total SPADI score at 12 months was 18.5 ± 5.8, as compared with 11.2 ± 3.4 in the corticosteroid group, 12.8 ± 3.6 in the physiotherapy group, and 15.7 ± 4.7 in the combination group. The patients in the placebo group also had a significant increase in their total shoulder ROM at 12 months (mean ± SD 264 ± 11.2° for active movement and 283 ± 11.3° for passive movement). The degree of improvement in pain, function, and ROM seen in the placebo group confirms the notion that adhesive capsulitis has a favorable natural history (6–8).
Sixteen patients did not complete all followup assessments, including 9 in the corticosteroid group, 4 in the physiotherapy group, 2 in the combination group, and 1 in the placebo group. The total SPADI score at each of the visits with available data for these 16 patients is shown in Table 6. Our primary analysis, in which data obtained at the last available visit were imputed to subsequent evaluations, assumed that no further improvement occurred after that visit. The natural history of adhesive capsulitis is such that most patients improve with time (6–8). Therefore, if any bias had been introduced by data imputation, it would have favored the combination and placebo groups, which had the least missing data. The results of the secondary analysis, which was carried out only with actual data, showed a larger treatment effect for the corticosteroid group, as compared with the other groups, than was shown in the primary analysis. For example, the total SPADI scores at 6 weeks, 3 months, 6 months, and 12 months, respectively, improved by a mean ± SEM of 42.4 ± 4.9, 50.6 ± 5.0, 57.9 ± 5.3, and 54.4 ± 5.8 in the corticosteroid group, compared with 46.5 ± 4.9, 50.4 ± 4.9, 53.0 ± 5.0, and 49.3 ± 5.1 in the combination group (P not significant). The only remaining significant difference between these 2 groups was in the magnitude of improvement in active ROM, which was greater in the combination group (mean ± SEM 80.7 ± 9.2° and 77.2 ± 8.7°, respectively) than the corticosteroid group (54.9 ± 9.2° and 54.1 ± 8.7°, respectively).
Table 6. Total Shoulder Pain and Disability Index scores in patients who did not complete all visits
|Group*||Baseline||6 weeks||3 months||6 months||12 months|
Our study has a number of strengths, including the use of strict selection criteria, the inclusion of a placebo arm, and the administration of the injections under fluoroscopic guidance. Recent studies indicate that injections performed blindly are inaccurate in as many as 60% of the cases and that injection accuracy is related to better clinical outcome (36, 37). The favorable results observed in groups 1 and 2 might have been less pronounced had the injections been administered blindly.
We devised our physiotherapy interventions based on the best evidence available and selected physiotherapists who were experienced in the management of shoulder disorders, including mobilization techniques. While our results cannot be generalized to other types of physiotherapy interventions, they apply to patients meeting our selection criteria and for the actual interventions used in the present study.
The main limitation of our study is that it was terminated early due to difficulties in recruiting patients who met the entry criteria. We had calculated our sample size in order to detect a difference of ≥10 points in the total SPADI scores between treatment groups. Because the confidence intervals of the differences between physiotherapy and placebo include −10, we cannot exclude the possibility of a small but clinically significant advantage of physiotherapy as compared with placebo, particularly at the 3-month assessment.
In conclusion, a single intraarticular injection of corticosteroid administered under fluoroscopy, combined with a simple home exercise program, is effective in improving shoulder pain and disability in patients with adhesive capsulitis. Supervised physiotherapy in conjunction with the corticosteroid treatment provides faster improvement in shoulder ROM. When used alone, supervised physiotherapy is of limited efficacy in the management of adhesive capsulitis.
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The authors wish to thank our collaborators: study coordinators Marie Métivier, Carmen Trudel, and Vicki Lapp; physiotherapists Annette Bailey, Normand Bastrash, Julie Bellemare, Sophie Bernard, Anne Botham, Christian Brideau, Marie-Andrée Brosseau, Aleks Chafranskaia, Anne Cloutier, Amy Dehueck, Lise Dion, Martine Gastonguay, Carol Kennedy, Anne Labrecque, Nancy Landry, Hélène Laroche, Nancy Lehoux, Annie Plamondon, Jennifer Simon, Sue Thiessen, Isabelle Vézina, and Riki Yamada; blinded evaluators Nadine Bellman, Andrea Bishop, Erika Cooke, Sophie Girard, Eugenia Krpan, and Julie Rodrigue; and radiologists Hugues Archambault, Vincent Bergeron, Jacques Drolet, Rob Graham, and David Salonen.