One-Year Outcome of Subacromial Corticosteroid Injection Compared With Manual Physical Therapy for the Management of the Unilateral Shoulder Impingement Syndrome

Context The shoulder impingement syndrome includes conditions, such as rotator cuff tendinosis and shoulder bursitis. Conservative management may include corticosteroid injections (CSIs) or manual physical therapy (MPT). Contribution In this randomized, controlled trial, groups of patients with the shoulder impingement syndrome receiving CSI or MPT showed similar symptom improvements that did not differ significantly. Compared with the MPT group, the CSI group used more health care resources during the 1-year follow-up. Caution The trial recruited only patients referred to MPT. Implication Manual physical therapy and CSI produced similar clinical outcomes in patients with the shoulder impingement syndrome. The Editors The shoulder impingement syndrome (SIS) is a generic term used for patients with shoulder pain that encompasses the rotator cuff syndrome, tendinosis of the rotator cuff muscles, and bursitis in the shoulder area (1). It has a cumulative incidence between 5 and 30 per 1000 person-years (2, 3). Conservative treatment options include corticosteroid injections (CSIs) and physical therapy. Subacromial CSI is one of the most common procedures used by orthopedists, rheumatologists, and general practitioners (4, 5). However, evidence to support long-term efficacy is conflicting (610). Clinical practice guidelines cannot recommend for or against CSI for rotator cuff pathology without evidence of tears (11). Four recent systematic reviews have differing conclusions on the efficacy of CSI for SIS (6, 8, 9, 12), but the consensus suggests that any benefit may only be short-term. Although manual physical therapy (MPT) may be effective for SIS management (1321), 2 recent systematic reviews found no clear evidence to suggest additional benefits of MPT to other interventions (22, 23), indicating the need for further research. Data are also lacking about the patterns and timing of CSI and MPT use for patients with SIS. Studies suggest that a CSI is often considered initially (4, 5), whereas a referral to physical therapy may occur only 24% of the time (24). Other studies introduced CSI only after 6 weeks of physical therapy was unsuccessful (5). Some investigations evaluated the effect of providing CSI before, or in conjunction with, MPT or shoulder exercises (14, 25, 26), but CSI and MPT have not been directly compared. The objective of this study was to compare the 1-year effectiveness of CSI and MPT for SIS management. Methods Design Overview This pragmatic, randomized, controlled trial compared 2 treatments for patients with SIS: subacromial CSI and MPT. The primary end point was 1-year improvement on the Shoulder Pain and Disability Index (SPADI). Secondary outcomes included changes in Global Rating of Change (GRC) scale and Numeric Pain Rating Scale (NPRS) scores and shoulder-related health care use. We followed the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) statement at the time of protocol development (27), and our reporting followed the CONSORT (Consolidated Standards of Reporting Trials) extension for pragmatic clinical trials (28). The study was approved by the Madigan Army Medical Center Institutional Review Board, the trial was registered (ClinicalTrials.gov: NCT01190891), and the protocol was published with open access (29). Setting and Participants Consecutive patients aged 18 to 65 years with a primary symptom of unilateral shoulder pain referred from family practice and orthopedic clinics to the physical therapy department at Madigan Army Medical Center were screened for eligibility during their initial visit in the physical therapy clinic. Exclusion criteria included a history of shoulder dislocation, fracture, or adhesive capsulitis; history of CSI or physical therapy for the shoulder pain in the past 3 months; baseline SPADI score less than 20%; reproduction of shoulder symptoms with cervical spine examination; history of systemic or neurologic disease affecting the shoulder; positive rotator cuff lag sign or history of full-thickness rotator cuff tear; pending litigation; or inability to attend physical therapy for 3 consecutive weeks. Patients at this medical center included a mix of active-duty and retired military service members and their families. Copayments were not required for care. Randomization and Interventions The randomization schedule was computer-generated, with assignments placed in opaque, sequentially numbered envelopes by an off-site investigator not involved with patient care or follow-up. Treatment allocation was revealed after collection of baseline outcomes. Patients and treating clinicians were not blind to the intervention. The research assistant who collected outcome assessments at each time point was blind to group assignment. Two physical therapists provided the MPT, and 1 physician administered all of the injections. Patients were allowed to continue any current medications prescribed by their primary care providers (PCPs). MPT Group At the first session, the physical therapists performed a standardized clinical examination to identify relevant impairments (weakness, mobility, or pain). The MPT intervention consisted of a combination of joint and soft-tissue mobilizations; manual stretches; contractrelax techniques; and reinforcing exercises directed to the shoulder girdle or thoracic or cervical spine. Specific details of the treatment are published (29). Patients did not receive identical treatments, but the MPT techniques were matched to individual impairments identified on examination. Patients were treated twice weekly over a 3-week period, a typical episode of care for SIS, by the same physical therapy in most cases. Home exercises were prescribed to reinforce clinic interventions (29). The physical therapists were fellowship-trained in MPT from an American Physical Therapy Associationcredentialed program. CSI Group A credentialed family practice physician with sports medicine fellowship training injected 40 mg of triamcinolone acetonide to the subacromial space of the symptomatic shoulder (29). Each participant received a handout explaining the effects of the steroid injection and how to manage potential side effects. As many as 3 total injections could be administered by the study physician (>1 month apart) during the 1-year period. Patients received printed instructions to perform a gentle gravity-assisted distraction and oscillatory pendulum exercise. Patients were discouraged, but not prohibited, from seeking additional care for at least the first month (study-related treatment period). At the 1-, 3-, and 6-month follow-up periods, patients were also given written instructions and a number to call if they believed that they were not improving and needed additional care. A study coordinator, who was not involved with data collection or treatment, fielded these calls. She advised patients in the MPT group to return to their PCP for additional care and facilitated contact with the physician providing the injection for patients in the CSI group. Each case was managed individually, and another CSI was administered if the patient and physician mutually agreed that it was appropriate. Patients in either group could return to their PCP if they felt the need, and the PCP would manage the patient as they thought best, potentially including a CSI or referral to physical therapy. These patients would not see the same physical therapist or physician who administered the initial study intervention. Outcomes and Follow-up Outcome measurements were administered at baseline, 1 month, 3 months, 6 months, and 1 year. The SPADI is a 100-point, 13-item, self-administered questionnaire that is divided into 2 subscales: a 5-item pain subscale and an 8-item disability subscale. It is valid, is responsive to change, and accurately discriminates between improving and worsening status (30, 31). The minimal clinically important difference for the SPADI is a change between 8 and 13 points (6% to 10%) (32). The GRC is an instrument that measures overall perceived changes in the participant's quality of life (33). It provides a valid measurement of change in patients' perceived status (34). A GRC score of 3 rating points or greater is clinically meaningful (35). An 11-point NPRS ranging from 0 (no pain) to 10 (worst imaginable pain) was used to assess pain intensity (36). This scale has been demonstrated to be a reliable, generalizable, and internally consistent measure of clinical and experimental pain intensity (37, 38). The suggested minimal clinically important difference for the NPRS is a change of 2 points (39). A research assistant blinded to treatment allocation collected health care use information from electronic health records at the 1-year follow-up using an established process (40, 41). This included additional use after completion of the study interventions. We identified shoulder-related visits to physical therapists, PCPs, rheumatologists, and orthopedists, as well as frequency and types of procedures, including additional steroid injections, magnetic resonance imaging, and radiography, similar to other studies (42). A second clinician manually verified the electronic health record information to ensure that the care was related to the same shoulder condition. Statistical Analysis The sample size estimated to achieve 80% power to detect a 12-point difference (or a 9.2% change) in the SPADI, based on a reported minimal clinically important difference range of 8 to 13 points (32), with an SD of 10 points, a 2-tailed test, and an level of 0.05 was 43 participants per group. To allow for a conservative withdrawal rate of approximately 20%, we recruited 104 participants. The primary analyses of effectiveness included all available data from patients who received their assigned treatment (that is, the CSI or at least 1 session of MPT). We used a linear mixed-effects model, which is flexible in accommodating data assumed to be missing at ra