Effectiveness of Surgical and Postsurgical Interventions for the Subacromial Impingement Syndrome: A Systematic Review

Transcription

1 1900 REVIEW ARTICLE (META-ANALY) Effectiveness of Surgical and Postsurgical Interventions for the Subacromial Impingement Syndrome: A Systematic Review Lukas Gebremariam, MD, Elaine M. Hay, FRCP, MD, Bart W. Koes, PhD, Bionka M. Huisstede, PhD ABSTRACT. Gebremariam L, Hay EM, Koes BW, Huisstede BM. Effectiveness of surgical and postsurgical interventions for the subacromial impingement syndrome: a systematic review. Arch Phys Med Rehabil 2011;92: Objective: To provide an evidence-based overview of the effectiveness of surgical and postsurgical interventions for the subacromial impingement syndrome. Data Sources: The Cochrane Library, PubMed, Embase, PEDro, and CINAHL were searched. Study Selection: Two reviewers independently selected relevant systematic reviews and randomized controlled trials (RCTs). Data Extraction: Two reviewers independently extracted data and assessed the methodologic quality. Data Synthesis: If pooling of data was not possible, a bestevidence synthesis was used to summarize the results. Results: One review and 5 RCTs reporting on various surgical techniques, and postsurgical interventions were included. Moderate evidence was found in favor of adding plateletleukocyte gel versus open subacromial decompression. No evidence was found for the superiority of subacromial decompression versus conservative treatment in the short, mid, and long term or in favor of 1 surgical technique when compared with another. Limited evidence was found in favor of early activation after arthroscopic decompression in the short and long term. Conclusions: This review shows that there is no evidence that surgical treatment is superior to conservative treatment or that1 particular surgical technique is superior to another. Because of possibly lower risks for complications, conservative treatment may be preferred. When choosing for surgery, arthroscopic decompression may be preferred because of the less invasive character of the procedure. Key Words: General surgery; Rehabilitation; Shoulder; Shoulder impingement syndrome; Treatment outcome by the American Congress of Rehabilitation Medicine THE SUBACROMIAL IMPINGEMENT syndrome () includes a number of pathologic entities: rotator cuff syndrome, tendonitis, and bursitis in the shoulder. 1 occurs when the soft tissues of the glenohumeral joint between the coracoacromial arch and the humeral tuberosity are compressed, disturbing the normative sliding mechanism when elevating the arm. Patients visiting their general practitioner with Complaints of the Arm, Neck and/or Shoulder (CANS), 1 that is, nontraumatic musculoskeletal complaints of the upper extremity not caused by any systemic disease, frequently report shoulder complaints 2 ; 33% of those with CANS are diagnosed with. 3 Work-related factors associated with the occurrence of include handling of loads frequently or with high force, highly repetitive work, hand-arm vibration, work above shoulder level, and high job demands (high work pressure and high emotional demands). 4 Affected patients complain of anterolateral shoulder pain that is worsened by active lifting of the arm into the impingement arc ( of shoulder abduction). 5 Also pain at night is frequently reported, exacerbated by lying on the involved shoulder, or sleeping with the arm overhead. 6 Various physical tests for diagnosing have been described, but it remains difficult for physicians to differentiate between the different types of tendonitis and bursitis around the shoulder. 1 According to Park et al, 7 the best combination of physical tests to diagnose is a positive Hawkins-Kennedy impingement sign (pain and resulting facial expression when applying forward flexion of the shoulder to 90 and internal rotation), a positive painful arc sign, and weakness in external rotation with the arm at the side. However, although physical tests are important, they may not be sufficient for appropriate diagnosis, because most tests for have greater sensitivity than specificity. 8 Therefore, in addition to the patient history, physical examination findings, and specific impingement test maneuvers (eg, Neer and Hawkins-Kennedy), radiologic evaluation with ultrasound and magnetic resonance imaging is recommended. 8 Current accepted approaches to treat include both conservative and surgical management. 9 Having clinical symptoms for over 1 year 10 and the severity of symptoms were reported to be prognostic factors for a negative outcome on conservative intervention. 9,10 When conservative approach fails, surgical treatment is considered. Currently there is no review that solely concentrates on the effectiveness of interventions for only. One Cochrane review 11 concentrates on surgical interventions to treat rotator cuff disease. Since the publication of the Cochrane review, new From the Departments of General Practice (Gebremariam, Koes, Huisstede); and Rehabilitation Medicine (Huisstede), Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands; the Arthritis Research Campaign National Primary Care Centre, Keele University, Keele, United Kingdom (Hay). 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. Reprint requests to Bionka M.A. Huisstede, PhD, Erasmus MC University Medical Center Rotterdam, Dept of Rehabilitation, Room H-016, PO Box 2040, 3000 CA Rotterdam, The Netherlands, b.huisstede@erasmusmc.nl /11/ $36.00/0 doi: /j.apmr ASD ASES CANS OSD PLG RCT ROM UCLA List of Abbreviations arthroscopic subacromial decompression American Shoulder and Elbow Surgeons Complaints of the Arm, Neck and/or Shoulder open subacromial decompression platelet-leukocyte gel randomized controlled trial range of motion subacromial impingement syndrome University of California at Los Angeles

2 SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam 1901 Table 1: Methodologic Quality Assessment: Sources of Risk Bias Items Risk of Bias 1. Was the method of randomization adequate? 2. Was the treatment allocation concealed? 3. Was the patient blinded to the intervention? 4. Was the care provider blinded to the intervention? 5. Was the outcome assessor blinded to the intervention? 6. Was the dropout rate described and acceptable? 7. Were all randomized participants analyzed in the group to which they were allocated? 8. Are reports of the study free of suggestion of selective outcome reporting? 9. Were the groups similar at baseline regarding the most important prognostic indicators? 10. Were cointerventions avoided or similar? 11. Was the compliance acceptable in all groups? 12. Was the timing of the outcome assessment similar in all groups? RCTs have been published, and we wondered whether the conclusions made in the Cochrane review would remain the same or would need modification. In order to further optimize the quality of care for patients with given by clinicians and paramedical staff, an overview regarding evidence-based information is needed that can support developing evidencebased treatment protocols and guidelines. The aim of the present study is to provide an evidence-based overview of the effectiveness of surgical and postsurgical interventions for. METHOD Search Strategy To identify relevant systematic reviews and randomized controlled trials (RCTs) on, a search was performed in the Cochrane Library, PubMed, Embase, PEDro, and CINAHL up to February Key words such as shoulder impingement syndrome and rotator cuff impingement and interventions were included in the literature search (appendix 1). Inclusion Criteria Systematic reviews and/or RCTs were considered eligible for inclusion if: (1) the study included patients with, (2) was not caused by an acute trauma or any systemic disease as described in the definition of CANS, (3) an intervention, including a postsurgical intervention, for treating was evaluated, (4) results on pain, function, or recovery were reported, and (5) a follow-up period of at least 2 weeks was reported. There were no language restrictions. Study Selection Two reviewers (L.G. and B.H.) independently applied the inclusion criteria to select potential relevant studies from the title and abstracts of the references retrieved by the literature search. A consensus method was used to solve any disagreements concerning inclusion of studies, and a third reviewer (B.K.) was consulted if disagreement persisted. Categorization of the Relevant Literature Relevant literature is categorized under 3 different headers: Systematic reviews describes all (Cochrane) reviews; Recent RCTs contains all RCTs published after the search date of the systematic review on the same intervention; Additional RCTs describes all RCTs concerning an intervention that has not yet been described in a systematic review. Data Extraction Two authors (L.G. and B.H.) independently extracted the data of the included studies. Information was collected on the study population, interventions, and outcome measures. The outcome evaluation was determined as short term if it occurred in less than 3 months (after baseline), middle term between 4 and 6 months, and long term when the follow-up period was longer than 6 months. Methodologic Quality Assessment To identify potential risks of bias of the included RCTs, 2 reviewers independently assessed the methodologic quality of each RCT, using the 12 quality criteria (table 1) of Furlan et al. 12 Each item was scored as yes, no, or unclear. High quality was defined as a yes score of 50% or more. A consensus procedure was used to solve disagreement between the reviewers. In a (Cochrane) review the use of a methodologic quality assessment is a standard procedure. We describe the methodologic quality scale or criteria that were used in the review, and have used their definitions of high and low quality of the included studies. Data Synthesis A quantitative analysis of the studies was not possible due to heterogeneneity of the outcome measures or study population. Therefore, we summarized the results using a rating system that consisted of 5 levels of scientific evidence (ie, best-evidence synthesis) 13 (table 2). An article was included in the best-evidence synthesis if a comparison was made between the study groups (treatment vs placebo/control/treatment), and the level of significance was reported. The study results were labeled significant if it reported significant results on 1 of the 3 outcomes. RESULTS Study Characteristics The initial literature search identified 5 reviews via the Cochrane Library, 5 reviews/215 RCTs via PubMed, 21 reviews/193 RCTs via Embase, 141 reviews/rcts via CINAHL, and 0 reviews/13 RCTs via PEDro were identified. Finally, 1 Cochrane review and 5 RCTs (all found in PubMed) were included. The Cochrane review of Coghlan et al, 11 studying the effectiveness of surgery for rotator cuff disease, included 14 trials; 11 (n 611) of these studies reported on (including Table 2: Levels of Evidence Strong evidence: consistent (ie, when 75% of the trials report the same findings), positive (significant) findings within multiple higher quality RCTs. Moderate evidence: consistent, positive (significant) findings within multiple lower quality RCTs and/or 1 high-quality RCT. Limited evidence for effectiveness: positive (significant) findings within 1 low-quality RCT. Conflicting evidence: provided by conflicting (significant) findings in the RCTs ( 75% of the studies reported consistent findings). No evidence: RCT(s) available, but no (significant) differences between the intervention and control groups were reported.

3 1902 SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam Table 3: Methodologic Quality Scores of the Included Recent and Additional RCTs Score Study % Maximum Score Timing of the Outcome Assessment Similar? Compliance Acceptable in all Groups? Cointerventions Avoided or Similar? Similarity of Baseline Characteristics? Free of Suggestions of Selective Outcome Reporting? Incomplete Outcome Data? ITT Analysis? Incomplete Outcome Data Addressed? Dropouts? Blinding? Outcome Assessors? Blinding? Caregiver? Blinding? Patients? Allocation Concealment? Adequate Randomization? Reference Everts et al 26? NA Taverna et al 25???? NA Hultenheim Klintberg et al 27?? Jarvela et al 29??? Hoe-Hansen and Norlin 28?????? Abbreviations:, yes; -, no;?, unclear/unsure; ITT, intention-to-treat; NA, not applicable (in a nontime intervention, eg, surgery, compliance is not an issue). calcific tendinitis) and met our inclusion criteria. Figure 1 shows the process of identifying the relevant articles. Furthermore, we included 5 additional RCTs: 2 studying surgery and 3 studying postsurgical interventions. Appendices 2, 3, and 4 show characteristics of the included studies. Methodologic Quality Tables 3 and 4 present the results of the methodologic quality assessment. Two of the 5 included RCTs were classified as high quality. The 3 low-quality RCTs scored 33% to 42% of the total score. The most prevalent methodologic flaws were: (1) care provider not blinded (75%) (as expected in surgery) and (2) no intention-to-treat analysis (75%) was applied by the authors of the RCTs. According to the authors of the Cochrane review, of the 11 RCTs had a high risk of bias, and 1 RCT had a medium to high risk of bias; 6 items were used to score the methodologic quality of these studies. Effectiveness of Surgical and Postsurgical Interventions to Treat A complete overview of the evidence is presented in table Effectiveness of Surgery 1.1. Arthroscopic or Open Subacromial Decompression Versus Conservative Treatment Systematic review. Three trials (n 258) compared either open 14 or arthroscopic 15,16 surgery with active nonoperative treatment. The low-quality study of Haahr et al 16 (n 90) found no differences between arthroscopic subacromial decompression and a graded physiotherapy strengthening program on the mean change in Constant score at 3, 6, and 12 months. Furthermore, there were no significant differences between the 2 treatment groups for the PRIM score (aggregated pain and dysfunction score used in Projects on Research and Intervention in Monotonous work) at 12 months, or between the number of participants with a good or excellent Constant score ( 80) at 12 months. A low-quality trial 14 (n 42) compared open subacromial decompression and a physiotherapy program of exercise and education. At 6- and 12-month follow-up, there were no significant differences between the groups for the number of participants who reported success of treatment or of those reporting success and partial success of treatment. Another low-quality study 15 (n 125) reported no differences in median Neer score between surgery and an exercise program at 3- and 6-month follow-up. No differences in the median pain scores (pain on activity, pain at rest, and pain at night) were reported between surgery and nonoperative treatment. Therefore, these low-quality trials found no evidence for the effectiveness of surgery (open or arthroscopic) compared with conservative treatment for treating in the short, mid, and long term Arthroscopic Versus Open Subacromial Decompression Systematic review. Five trials (n 248) compared arthroscopic (ASD) versus open subacromial decompression (OSD) for. A low-quality trial 17 (n 32) found no differences between the groups on pain at rest at 3-, 6-, and 12-month follow-up. Also, on pain with activity and the mean University of California and Los Angeles (UCLA) shoulder rating scale score no significant differences between ASD and OSD were found at 3-, 17 6-, , or 96-month 17 follow-up.

4 SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam 1903 Fig 1. Flowchart of the literature search. A low-quality trial 19 (n 44) reported equivalent pain scores for both groups at time points up to 1 year. Also, in another low-quality trial 20 (n 46) there were no significant differences on the mean UCLA shoulder rating scale score between ASD and OSD (follow-up time unclear). Two low-quality trials 20,21 (n 97) reported no significant differences between the groups on the proportion of participants with a good or excellent UCLA shoulder rating scale score. The Constant score, measured in a low-quality trial, 18 showed no significant difference between ASD and OSD. Further, no differences between both groups on range of motion (ROM) were found at 1-year follow-up. In 2 lowquality trials 17,19 no significant differences were found between ASD and OSD for muscle strength, at any evaluation period. Therefore, there is no evidence for the effectiveness of ASD and OSD in the short, mid, and long term OSD: Neer Versus Modified Neer Technique One low quality trial 22 reported differences in abduction between the Neer and modified Neer technique in OSD after 8 weeks, but this could not be verified from the data. Reference Table 4: Methodologic Quality Scores of the Included Cochrane Review of Coghlan et al 11 Randomization? Allocation Concealment? Blinding Patients? Blinding? Outcome Assessors? Acceptable? No. Lost to Follow-up? Intention-to-Treat Analysis? Score Maximum Score Study % Overall Validity Brox et al 15? C Low Haahr et al B C Low Husby et al 17? NS C Low Murphy et al 24?? NS C Low Iversen et al 20?? C Low Rahme et al 14? C Low Spangehl et al 21?? NS C Low T Jonck et al 18???? C Low Ingvarrson et al 22???? NS C Low Rubenthaler 23????? C Low Sachs et al 19?? NS C Low Abbreviations:, yes; -, no;?, unclear; No. lost to follow-up, we defined this item positive if the percentage of lost to follow-up is 20% for the short-term follow-up and 30% for the long-term follow-up; NS, not stated but participants completed within their surgical allocation; Overall validity, A (low risk of bias), all criteria met; B (moderate risk of bias), 1 or more criteria partly met; C (high risk of bias), 1 or more criteria not met. Quality of the Study

5 1904 SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam Table 5: CANS: Evidence for Effectiveness of Surgical and Postsurgical Interventions for Subacromial Impingement Syndrome Surgery vs Conservative Postsurgery ASD or OSD vs conservative: Ketoprofen* after ASD vs control: Short term Short term Mid term Long term Long term Early activation* vs protective activation physiotherapy after ASD ASD vs OSD: ASD vs OSD: Short term Short term Long term Mid term Long term Pain pump vs control after ASD: Long term ASD vs OSD for removal of calcium deposits: Short term Mid term OSD: Neer vs modified Neer technique: Short term ASD: ASD using electrocautery* vs using a Holium laser: Short term Mid term Long term ASD vs radiofrequency-based plasma microtenotomy: Short term Mid term Long term In surgery: PLG* vs control in OSD Short term Abbreviations:, limited evidence found;, moderate evidence found;, no evidence found for effectiveness of the treatment: RCT(s) available, but no differences between intervention and control groups were found. *In favor of. There is no evidence for effectiveness of the Neer versus the modified Neer technique in OSD ASD Versus OSD to Remove Calcium Deposit in Calcific Tendonitis Systematic review. A low-quality study 23 (n 38) compared ASD and OSD to remove calcium deposits in patients with calcific tendonitis. No significant differences between the groups were reported on pain relief and subjective ratings of shoulder function at 16-month follow-up or average duration of postoperative physiotherapy. There is no evidence for the effectiveness of ASD compared with OSD to remove calcium deposits in patients with calcific tendonitis in the short and mid term Electrocautery Versus Holium Laser in ASD Systematic review. A low-quality study 24 (n 49) compared 2 different ASD techniques: holium laser versus electrocautery. No significant results were found on the UCLA shoulder rating scale scores at 3-, 6-, and 12-month follow-up. A small significant difference between the groups in favor of the electrocautery group was found in the American Shoulder and Elbow Surgeons (ASES) score at 6-month follow-up (weighted mean difference, 8.00; 95% confidence interval, to 0.38). No significant differences between the groups on the ASES score were found at 3- and 12-month follow-up. There is limited evidence for the effectiveness of electrocautery compared with the holium laser in ASD in the short and mid term and no evidence for the long term ASD Versus Radiofrequency-Based Plasma Microtenotomy Recent RCT. A high-quality study 25 (n 60) examined ASD versus radiofrequency-based plasma microtenotomy. After 3, 6, and 12 months, no significant differences were found between the groups for the visual analog scale, ASES, UCLA shoulder rating scale, and the Constant score. Therefore, there is no evidence for the effectiveness of ASD versus radiofrequency-based plasma microtenotomy to treat in the short, mid, and long term Platelet-Leukocyte Gel as Add-On Therapy in OSD Additional RCT. A high-quality RCT 26 (n 40) studied the effect of platelet-leukocyte gel (PLG) on postoperative recovery of patients undergoing OSD. Only patients in the treatment group were injected with PLG. Six weeks postoperatively, the PLG group showed a significant (P.001) decrease in pain compared with the control group (no exact data given). Further, a significantly better shoulder index score (P.001) was found in favor of the PLG group compared with the controls at 6-weeks follow-up (no exact data given). There were no significant differences (P.13) on shoulder instability scores between the 2 groups at 6-weeks follow-up. The PLG group showed significantly (P.05) more activities in daily living than the control group and showed significantly (P.001) improved ROM at 12-weeks follow-up (no exact data given). Therefore, there is moderate evidence for the effectiveness of

6 SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam 1905 PLG on postoperative recovery of patients undergoing OSD in the short-term. 2. Effectiveness of Postsurgery Treatments 2.1. Early Activation Versus Protective Physiotherapy After ASD Additional RCT. A low-quality RCT 27 compared 2 different physiotherapy protocols in patients (n 33) with who had ASD. A traditional group received active assisted dynamic exercises for the rotator cuff 6 weeks after operation (3 times per day) and strengthening exercises 8 weeks after operation. A progressive group received active assisted ROM exercises 1 day after operation (3 times per day) and strengthening exercises 6 weeks after operation (3 times per day). Both groups showed significant improvements in pain during activity and at rest at 12-month follow-up. There were also significant (P.05) improvements in ROM in extension and abduction between the groups at 3- and 12-month follow-up in favor of the progressive group. The Constant score was significantly (P 0.05) higher in the progressive group at 6-weeks followup, but not at 3-month follow-up. There is limited evidence for the effectiveness of progressive physiotherapy in the short and long term compared with traditional physiotherapy Ketoprofen Versus Placebo After ASD Additional RCT. A low-quality study 28 compared ketoprofen 200mg once daily for 6 weeks (n 21) with the placebo (n 20) in patients who had ASD. After 6 weeks, the number of patients showing mild or no pain was significantly higher in the ketoprofen group compared with the placebo group (ketoprofen: 16 of 19 vs placebo: 9 of 19, P.005). Further, significant results (P.05) were reported in favor of the ketoprofen group on the UCLA shoulder rating scale score, active forward flexion, and active abduction at 6-weeks follow-up. These significant differences on the short term did not sustain at 2-years follow-up. Therefore, there is limited evidence for ketoprofen after ASD in the short-term and no evidence in the long-term Pain Pump After ASD Additional RCT. A low-quality RCT 29 compared the use of a pain pump with 0.375% ropivacaine after ASD as add-on therapy with a rehabilitation group (n 50). At 2-years followup, no significant differences were found between the groups on the UCLA shoulder rating scale score (P.845) and on the Constant score (P.243). There is no evidence in the long term for the effectiveness of a pain pump as add-on therapy to rehabilitation after ASD in patients with. DISCUSSION In general, patients failing to respond to conservative treatments are considered for surgery. In the present review no evidence was found for the superiority of subacromial decompression (arthroscopic or open) compared with conservative treatment in the short, mid, and long term. However, our conclusion is based on only 3 low-quality studies that included a small number of patients. Although no significant results were found between surgery and conservative treatment, 1 study 16 found better within-group results (ie, significant outcome when the pre- and posttreatment results were compared) in the conservative group, and another study 15 found better within-group results in the surgery group. The third study stated that if an intention-to-treat analysis was conducted, the effectiveness of surgery should be favorable. 14 In general, surgical interventions for treating subacromial impingement are associated with more complications and higher costs than conservative treatment. 15 One review found exercise therapy to be 1 of the most effective conservative intervention to treat in the short and mid term (Gebremariam, unpublished data, 2011). More studies are needed to further elucidate the evidence for differences in outcome between surgery and conservative interventions. If patients are treated surgically, either OSD or ASD can be performed. In the present review no evidence was found for the superiority of ASD or OSD in the short, mid, and long term. This conclusion is based on 5 low-quality studies with relatively small groups of patients. ASD tends to give a faster recovery due to its less invasive nature. 19,30 No trials were found that focused on defining an optimal timing strategy for surgery; future studies should focus on this important topic. For within-surgery techniques, moderate evidence was found for the effectiveness of PLG as add-on therapy to OSD, and limited evidence was found for using electrocautery in ASD versus using the holium laser. Only a few RCTs were found studying postsurgical management. Limited evidence was found in favor of early activation after ASD versus protective activation in the short and long term, and for ketoprofen after ASD in the short term (although the latter effect did not sustain in the long term). Thus, if surgery is required, it seems that postsurgical intervention can influence the outcome of surgery. Study Limitations This review has some limitations. In general, the methodologic quality of the included studies was low; only 2 highquality RCTs were found. This may be a result of inadequate reporting in the studies. Four of the 5 included RCTs failed to mention allocation concealment and whether or not cointerventions were avoided or similar. The included Cochrane review of Coghlan et al 11 used different methodologic quality criteria compared with our criteria based on Furlan et al. 12 Because of the high credibility and validity of Cochrane reviews, we decided to apply the methodologic quality criteria and definitions of high-quality and low-quality studies used in a Cochrane review. However, the quality criteria of the Cochrane reviews 11 included fewer items than our 12 quality criteria, and high quality was not defined as at least 50% of the items were scored positive. This could contribute to bias in the outcome of evidence and conclusions. If we would we have used our definition that a study is classified as high quality if at least 50% of the items were scored positive, 3 of the 11 RCTs would have been classified as high-quality studies (see table 3). However, in this case, our conclusions regarding the evidence for effectiveness of the interventions would remain similar. Further, it should be addressed that the power of some studies was low, because only a small number of patients were included; maybe because of this, no statistically significant differences between the groups were found. CONCLUSIONS This review shows that there is no evidence that surgical treatment is superior to conservative treatment or that 1 particular surgical technique is superior to another to treat. Because of lower costs and possibly lower risk of complications, conservative treatment may be preferred to surgery. When choosing surgery, arthroscopic decompression may be

7 1906 SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam preferred because of the faster recovery of ROM and the minimally invasive character of the procedure. Furthermore, early activation postsurgery might have positive results but additional studies are required to confirm this statement. Acknowledgement: We thank M.S. Randsdorp (MR), MD, for her participation in the quality assessment. APPENDIX 1: SEARCH STRATEGY PubMed shoulder impingement syndrome [mh] OR rotator cuff [mh] OR rotator cuff OR (subacrom* AND impingement) OR (shoulder AND impingement) OR ((shoulder OR shoulder pain [mh] OR supraspinatus OR supraspinatus OR infraspinatus OR infra-spinatus OR subscapularis OR sub-scapularis OR teres minor ) AND (tendinopathy[mh:noexp] OR tenovaginitis OR tendovaginitis OR tendinit* OR tendonitis OR tenosynovitis OR tendinos* OR bursitis[mh:noexp])). Therapy (randomized controlled trial[publication Type] OR (randomized[title/abstract] AND controlled[title/abstract] AND trial[title/abstract])). Systematic reviews ((meta-analysis [pt] OR meta-analysis [tw] OR metanalysis [tw]) OR ((review [pt] OR guideline [pt] OR consensus [ti] OR guideline* [ti] OR literature [ti] OR overview [ti] OR review [ti]) AND ((Cochrane [tw] OR Medline [tw] OR CINAHL [tw] OR (National [tw] AND Library [tw])) OR (handsearch* [tw] OR search* [tw] OR searching [tw]) AND (hand [tw] OR manual [tw] OR electronic [tw] OR bibliographi* [tw] OR database* OR (Cochrane [tw] OR Medline [tw] OR CINAHL [tw] OR (National [tw] AND Library [tw]))))) OR ((synthesis [ti] OR overview [ti] OR review [ti] OR survey [ti]) AND (systematic [ti] OR critical [ti] OR methodologic [ti] OR quantitative [ti] OR qualitative [ti] OR literature [ti] OR evidence [ti] OR evidence-based [ti]))) BUTNOT (case* [ti] OR report [ti] OR editorial [pt] OR comment [pt] OR letter [pt]). RCTs (randomized controlled trial [pt] OR controlled clinical trial [pt] OR randomized controlled trials [mh] OR random allocation [mh] OR double-blind method [mh] OR single-blind method [mh] OR clinical trial [pt] OR clinical trials [mh] OR clinical trial [tw] OR ((singl* [tw] OR doubl* [tw] OR trebl* [tw] OR tripl* [tw]) AND (mask* [tw] OR blind* [tw])) OR latin square [tw] OR placebos [mh] OR placebo* [tw] OR random* [tw] OR research design [mh:noexp] OR comparative study [mh] OR evaluation studies [mh] OR follow-up studies [mh] OR prospective studies [mh] OR cross-over studies [mh] OR control* [tw] OR prospectiv* [tw] OR volunteer* [tw]) NOT (animal [mh] NOT human [mh]). Embase shoulder impingement syndrome /OR ((shoulder/or shoulder) AND impingement) OR rotator cuff /OR rotator cuff OR (subacrom* AND impingement) OR ((shoulder/or shoulder OR supraspinatus OR supra-spinatus OR infraspinatus OR infra-spinatus OR subscapularis OR sub-scapularis OR teres minor ) AND (tendinopathy OR tendovaginitis OR tendovaginitis/or tendinit* OR tendonitis OR tendinitis/or tenosynovitis/or tendinos* OR bursitis/)). Therapy randomized controlled trial :it OR (randomized: ti,ab AND controlled:ti,ab AND trial:ti,ab). Systematic reviews ( review /exp AND (medline:ti,ab OR medlars:ti,ab OR embase:ti,ab OR pubmed:ti,ab) OR scisearch:ti,ab OR psychlit:ti,ab OR psyclit:ti,ab OR psycinfo: ti,ab OR pyschinfo:ti,ab OR cinahl:ti,ab OR hand search : ti,ab OR manual search :ti,ab OR electric database :ti,ab OR bibliographic database :ti,ab OR pooled analysis :ti,ab OR pooled analyses :ti,ab OR pooling:ti,ab OR peto:ti,ab OR dersimonian:ti,ab OR fixed effect :ti,ab OR mantel haenszel :ti,ab OR retracted article :ti,ab) OR ( meta analysis / exp OR meta analysis OR meta-analysis OR meta-analyses :ti,ab OR meta analyses :ti,ab OR systematic review : ti,ab OR systematic overview :ti,ab OR quantitative review :ti,ab OR quantitativ overview :ti,ab OR methodologic review :ti,ab OR methodologic overview :ti,ab OR integrative research review :ti,ab OR research integration :ti,ab OR quantitative synthesis :ti,ab). RCTs ( controlled clinical trial /exp OR randomized controlled trial :ti OR controlled clinical trial :it OR randomization /OR double blind procedure /OR single blind procedure /OR crossover procedure /OR clinical trial :it OR (( clinical trial OR (singl* OR doubl* OR tripl*)) AND (mask* OR blind*)) OR ( Latin square design /OR latin square OR latin-square ) OR placebo /OR placebo* OR random sample /OR comparative study :it OR evaluation study :it OR evaluation/exp OR follow up /exp OR prospective study /OR control* OR prospectiv* OR volunteer*) NOT (animals/exp NOT humans/exp). CINAHL (MH Shoulder impingement syndrome ) or (MH rotator cuff )or rotator cuff or (subacrom* and impingement) or (((MH shoulder ) or (MH shoulder joint ) or shoulder) and impingement) or (((MH shoulder ) or (MH shoulder joint ) or shoulder or (MH shoulder pain ) or supraspinatus or supra-spinatus or infraspinatus or infraspinatus or subscapularis or sub-scapularis or teres minor ) and ((MH Tendinitis ) or (MH tenosynovitis ) or tend* or tenovaginitis or tendovaginitis)). Reviews (MH Systematic Review ). Clinical trials (MH Clinical Trials ). PEDro Subacromial impingement syndrome, Rotator cuff syndrome, impingement syndrome Table a1, a2, a3.

8 APPENDIX 2: DATA EXTRACTION SYSTEMATIC REVIEWS Author Total No. of Patients Treatment Placebo Control/Comparison Outcome Measures Effect Size Coghlan et al 11 Haahr et al 16 Rahme et al 14 SURGERY Surgery (open or arthroscopic) vs. conservative treatment 90 Arthroscopic surgery Conservative therapy (heat and (n 41) cold packs, active training, and strengthening exercise) (n 43) Mean change in Constant score 3mo: WMD, 4.60 (95% CI, to 3.28) 6mo: WMD, 1.40 (95% CI, to 7.63) 12mo: WMD, 4.50 (95% CI, to 4.73) Mean PRIM score (12mo) WMD, 0.0 (95% CI, 4.77 to 4.77) Constant score 80 (12mo) RR 1.05 (95% CI, 0.49 to 2.25) 42 Open surgery Conservative therapy (exercise Success (reduction of 100% 6mo: RR 1.07 (95% CI, 0.34 to 3.40) and education) pain score from baseline) 12mo RR 1.89 (95% CI, 0.81 to 4.41) (n 21) (n 18) Success and partial success 6 mo: RR 1.71 (95% CI, 0.81 to 3.63) (reduction of 100% pain 12 mo: RR 1.25 (95% CI, 0.80 to 1.93) score or reduction 51-99% pain score from baseline) Brox et al Arthroscopic surgery (n 45) Supervised exercise (n 50) Neer score Sex-adjusted difference in median Neer score Baseline: arthroscopic: 64 (median) vs exercise: mo: arthroscopic: 84 vs exercise: 74 6mo: arthroscopic: 87 vs exercise: 86 3mo: 3.6 (95% CI, 0.2 to 7.4) 6mo: 2.0 (95 % CI, 1.4 to 5.4) Arthroscopic vs open surgery Husby et al Arthroscopic Open surgery Mean pain at rest 3mo: WMD, 1.00 (95% CI, to 15.59) (n 15) (n 17) (VAS 0 100) 6mo: WMD, 8.60 (95% CI, to 0.20) (n 14) (n 18) 12mo: WMD, 2.70 (95% CI, 7.82 to 2.42) (n 15) (n 16) 96mo: not estimable (n 15) (n 19) Mean pain during activity (VAS 3mo: WMD, 0.0 (95% CI, to 19.77) 0 100) (n 15) (n 17) 6mo: WMD, (95% CI, to 6.46) (n 14) (n 18) 12mo: WMD, 3.00 (95% CI, to 14.67) (n 15) (n 16) 96mo: WMD, 0.0 (95% CI, to 12.86) (n 15) (n 19) Sachs et al Arthroscopic surgery Open surgery Pain Equivalent pain scores at 12, 26, and 52wk (no data given) (n 19) (n 22) Husby et al Arthroscopic surgery Open surgery Mean UCLA score 3mo: WMD, 0.0 (95% CI, 4.53 to 4.53) (n 15) (n 17) 6mo: WMD, 1.00 (95% CI, 3.96 to 5.96) SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam 1907

9 APPENDIX 2: DATA EXTRACTION SYSTEMATIC REVIEWS (Cont d) Author Total No. of Patients Treatment Placebo Control/Comparison Outcome Measures Effect Size Husby et al, 17 (n 32) (n 31) Mean UCLA score 12mo: WMD, 1.61 (95% CI, 1.22 to 4.44) Tjonck et al 18 Husby et al 17 (n 15) (n 17) Mean UCLA score 96mo: WMD, 0.0 (95% CI, 4.00 to 4.00) Iversen et al Arthroscopic Open surgery Mean UCLA score WMD, 0.40 (95% CI, 3.43 to 4.14) (n 21) (n 20) (FU time unclear) Good or RR 0.94 (95% CI, 0.65 to 1.35) excellent (n 23) (n 23) UCLA score (FU time unclear) Spangehl et al (n 27) (n 24) Good or excellent RR 1.00 (95% CI, 0.68 to 1.48) UCLA score (FU time unclear) Tjonck et al (36 shoulders) Arthroscopic Open surgery Mean Constant score WMD, 6.20 (95% CI, 6.14 to 18.54) (n 17) (n 15) Tjonck et al (36 shoulders) Arthroscopic Open surgery Mean ROM: Active elevation WMD, 2.20 (95% CI, to 17.83) (n 17) (n 15) (12mo) (n 17) (n 15) Abduction WMD, (95% CI, 2.68 to 32.68) (n 17) (n 15) External rotation (passive) WMD, (95% CI, to 9.32) (n 17) (n 33) Internal rotation (passive) WMD, 3.60 (95% CI, 5.71 to 12.91) Husby et al Arthroscopic (n 11) Open surgery (n 13) Mean muscle strength: external rotation at 60 /s 3mo: WMD, 7.00 (95% CI, to 35.45) (n 14) (n 17) 6mo: WMD, 3.00 (95% CI, to 39.00) (n 13) (n 17) 12mo: WMD, (95% CI, to 30.72) (n 13) (n 18) 96mo: WMD, (95% CI, to 61.06) (n 11) (n 13) Mean muscle strength: external rotation at 180 /s 3mo: WMD, 3.00 (95% CI, to 34.21) (n 14) (n 17) 6mo: WMD, 7.00 (95% CI, to 39.40) (n 13) (n 17) 12mo: WMD, 0.0 (95% CI, to 37.47) (n 13) (n 18) 96mo: WMD, (95% CI, to 24.94) (n 11) (n 13) Mean muscle strength: internal rotation at 60 /s 3mo: WMD, (95% CI, to 97.36) (n 14) (n 17) 6mo: WMD, (95% CI, to 82.74) (n 13) (n 17) 12mo: WMD, (95% CI, to 78.03) (n 13) (n 18) 96mo: WMD, (95% CI, to ) (n 11) (n 13) Mean muscle strength: internal rotation at 180 /s 3mo: WMD, 1.00 (95% CI, to 68.84) 1908 SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam

10 APPENDIX 2: DATA EXTRACTION SYSTEMATIC REVIEWS (Cont d) Author Total No. of Patients Treatment Placebo Control/Comparison Outcome Measures Effect Size (n 14) (n 17) 6mo: WMD, (95% CI, to 78.43) (n 13) (n 17) 12mo: WMD, (95% CI, to 76.17) (n 13) (n 18) 96mo: WMD, (95% CI, to ) Sachs et al Arthroscopic surgery Open surgery Strength No difference (no data given) (n 19) (n 22) Improvement (participant evaluation, Moderate, or complete improvement) 12mo: RR 0.94 (95% CI, 0.78 to 1.12) Open surgical decompression: Neer vs modified Neer technique Ingvarrson et al Neer technique Modified Neer technique Mean degrees of movement (8wk) From baseline to 8-wk follow-up: Flexion: Neer: 115 to 150 vs modified Neer: 125 to 160 Extension: Neer: 40 to 50 vs modified Neer: 40 to 55 Abduction: Neer: 105 to 145 vs modified Neer: 80 to 160 Exo-rotation: Neer: 45 to 60 vs modified Neer: 50 to 65 Endo-rotation: Neer: 65 to 70 vs modified Neer: 70 to 70 Arthroscopic vs open removal of calcium deposit Rubenthaler et al Arthroscopic surgery Open surgery Mean pain score (VAS) WMD, 0.30 (95% CI, 1.46 to 0.86) (n 14) (n 19) (16mo) Calcific tendinitis Mean shoulder function (VAS) WMD, 0.50 (95% CI, 2.08 to 1.08) (16mo) Improvement: mean time of physiotherapy (wk) WMD, 5.00 (95% CI, to 20.51) Holium-laser vs electrocautery in arthroscopic subacromial decompression (Murphy et al 24 ) 48 (49 shoulders) Arthroscopic Arthroscopic acromioplasty Mean UCLA score 3mo: WMD, 1.00 (95% CI, 2.99 to 0.99) acromioplasty using a Holium laser using electrocautery (n 25) (n 24) 6mo: WMD, 1.00 (95% CI, 3.32 to 1.32) 12mo: WMD, 2.00 (95% CI 0.53 to 4.53) (n 25) (n 24) Mean ASES score 3mo: WMD, 7.00 (95% CI, 8.85 to 14.85) 6mo: WMD, 8.00 (95% CI, to 0.38) ifo electrocautery. 12mo: WMD, 3.00 (95% CI, 5.96 to 11.96) Abbreviations: CI, confidence interval; FU, follow-up; ifo, in favor of; RR, relative risk; PRIM, aggregated pain and dysfunction score used in Project on Research and Intervention in Monotonous work (range, 0 36); WMD, weighted mean difference; VAS, visual analog scale. SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam 1909

11 APPENDIX 3: DATA EXTRACTION RECENT RCTS Author Treatment Placebo Control/Comparison Outcome Measures and FU Time Results Statistical (P) Results Words SURGERY Subacromial decompression vs radiofrequency-based plasma microtenotomy Treatment vs comparison Taverna et al 25 ASD RF-based arthroscopic VAS (range, 0 10) (baseline).470 Mean SD, 8 1 vs8 1 microtenotomy Supraspinatus (n 30) (n 30) ASES (range max 100) (baseline) vs39 4 tendinosis UCLA (range max 35) (baseline) vs17 2 Constant score (range max 100) vs51 11 (baseline) VAS (range, 0 10) (3mo, 6mo, 1y).416 The pain reduction profile was statistically similar for both groups. ASES (range max 100) (3mo, 6mo, 1y).964 Improvement across time was statistically similar for both groups. UCLA (range max 35) (3mo, 6mo, 1y).794 Improvement across time was statistically similar for both groups. Constant score (range max 100) (3mo, 6mo, 1y).978 Improvement in scores across time were statistically similar for both groups. PLG as add-on to OSD Everts et al 26 PLG injection after OSD (n 20) OSD only (n 20) Pain (VAS) (6wk).001 PLG vs control, decrease in pain ifo PLG (no exact data given) Use of pain medication (3mo) no P given PLG used less pain medication than control (no exact data given) Shoulder index score (calculated from ADL score and VAS score) (6wk) Instability score (selfassessment) (VAS).001 NS Sig. better results ifo patients with PLG (no exact data given) Preoperative: PLG: mean SD, vs control: (6wk).13 6wk: PLG: vs control: ADL (questionnaire) (6wk).05 more activities ifo PLG (no exact data given) ROM.001 2wk: Sig. improvement ifo PLG (12wk) p and 12wk: Sig. improvement ifo PLG Abbreviations: ADL, activities of daily living; ASD, arthroscopic subacromial decompression; FU, follow-up; ifo, in favor of; RF, radiofrequency; max, maximum; NS, not significant; Sig., significant; VAS, visual analog scale (range, 0 10) SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam

12 Author Treatment Placebo Control/Comparison APPENDIX 4: DATA EXTRACTION ADDITIONAL RCTS Outcome Measures and FU Time Results Statistical (P) Results Words POSTSURGERY Hultenheim PG (active-assisted TG Pain during activity PG vs TG, median (range) Klintberg et al 27 ROM exercises on day 1 of (active- assisted dynamic (VAS) NS Baseline: 72 (30 100) vs 67 surgery (3 /d) and strengthening exercises after 6wk exercises for rotator cuff after 6wk (3 /d) and strengthening exercises after 8wk post operative (3 /d)(n 13) (24mo) No P given (0 97) (n 20) No P given 3mo: 5 (0 78) vs 20 (0 75) No P given 6mo: 14 (0 70) vs 12 (0 70) No P given 12mo: 2 (0 35) vs 23 (0 84) PG vs TG, median (range) Pain during rest NS Baseline: 30 (9 72) vs 50 (0 95) (VAS) No P given 3mo: 0 (0 63) vs 10 (0 82) (24mo) No P given 6mo: 1 (0 63) vs 0 (0 30) No P given 12mo: 0 (0 33) vs 5 (0 46) PG vs TG, median (range) ROM: (degrees) NS Baseline: 150 (95 170) vs 145 (90 180) Flexion:.05 6wk: 160 ( ) vs 140 (85 170) No P given 3mo: 160 ( ) vs 150 (90 170) No P given 6mo: 165 ( ) vs 150 (85 180) No P given 12mo: 160 ( ) vs 150 ( ) Extension PG vs TG, median (range) NS Baseline: 40 (25 55) vs 40 (15 75) No P given.05 3mo: 50 (40 60) vs 40 (20 70) ifo PG No P given 6mo: 50 (30 70) vs 40 (20 70) No P given 12mo: 50 (35 60) vs 40 (30 65) Abduction NS PG vs TG, median (range) No P given Baseline: 170 (50 180) vs 150 (25 180).05 3mo: 180 ( ) vs 160 (70 180) ifo PG No P given 6mo: 180 (90 180) vs 170 (85 180).05 12mo: 180 ( ) vs 170 (80 180) ifo PG Shoulder function: NS PG vs TG, median (range) Constant score (24mo) (no P given) Baseline: 57 (40 89) vs 46 (17 78).05 6wk: 67 (34 96) vs 48 (18 78), ifo PG No P given 3mo: 80 (60 88) vs 59 (19 94) No P given 6mo: 84 (35 94) vs 72 (30 97) No P given 12mo: 87 (63 96) vs 69 (22 97) SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam 1911

13 Author Treatment Placebo Control/Comparison Hoe-Hansen et al 28 Jarvela et al 29 ASD plus ketoprofen 200mg 1 /d for 6wk (n 21) Study group: pain pump with 0.375% ropivacaine infusion at continuous rate of 5mL/h in the subacromial space plus rehabilitation (ie, a sling for the first night, free ROM on first day after surgery and physiotherapy) (n 25) APPENDIX 4: DATA EXTRACTION ADDITIONAL RCTS (Cont d) ASD plus placebo (n 20) Control group only rehabilitation (n 25) Outcome Measures and FU Time No. of patients showing mild or no pain Results Statistical (P).05 Results Words Treatment vs placebo: 6wk: 16/19 vs 9/19 NS 2y: 14/17 vs 10/15 (No P given) Mean UCLA score.05 Treatment: mean (range), 16 (8 27) at baseline to 30 (16 35) at 6-wk FU vs placebo: 16 (19 22) at baseline to 26 (16 35) at 6-wk FU NS At 2-y FU: Treatment: 31 (17 35) vs placebo 29 (16 35) (No P given) Active forward flexion (degrees) Active abduction (degrees) UCLA score (2y) Constant score (2y).05 NS (No P given).05 NS (No P given) Abbreviations: FU, follow-up; ifo, in favor of; NS, not significant; PG, progressive group; TG, traditional group; VAS, visual analog scale (range, 0 10) Treatment: 145 (80 180) at baseline to 173 (90 180) at 6-wk FU vs placebo: 149 (70 180) to 169 (90 180) at 6-wk FU. At 2-y FU: data not given Treatment: 124 (50 180) at baseline to 169 (90 180) at 6-wk FU vs placebo: 128 (45 180) at baseline to 165 (70 180) at 6-wk FU At 2-y FU: data not given Study group vs control group (Mean SD) Baseline: 20 3 vs18 4 2y: 33 3 vs33 4 Study group vs. control group (Mean SD) Baseline: vs years: 94 8 vs SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam

14 SURGICAL TREATMENT SUBACROMIAL IMPINGEMENT SYNDROME, Gebremariam 1913 References 1. Huisstede BM, Miedema HS, Verhagen AP, Koes BW, Verhaar JA. Multidisciplinary consensus on the terminology and classification of complaints of the arm, neck and/or shoulder. Occup Environ Med 2007;64: Huisstede BM, Wijnhoven HA, Bierma-Zeinstra SM, Koes BW, Verhaar JA, Picavet S. Prevalence and characteristics of complaints of the arm, neck, and/or shoulder (CANS) in the open population. Clin J Pain 2008;24: Feleus A, Bierma-Zeinstra SM, Miedema HS, Verhaar JA, Koes BW. Management in non-traumatic arm, neck and shoulder complaints: differences between diagnostic groups. Eur Spine J 2008; 17: van Rijn RM, Huisstede BM, Koes BW, Burdorf A. Associations between work-related factors and specific disorders of the shoulder--a systematic literature review of the literature. Scand J Work Environ Health 2010;36: Neer CS 2nd. Impingement lesions. Clin Orthop Relat Res 1983; (173): Koester MC, George MS, Kuhn JE. Shoulder impingement syndrome. Am J Med 2005;118: Park HB, Yokota A, Gill HS, El Rassi G, McFarland EG. Diagnostic accuracy of clinical tests for the different degrees of subacromial impingement syndrome. J Bone Joint Surg Am 2005;87: Silva L, Andréu JL, Muñoz P, et al. Accuracy of physical examination in subacromial impingement syndrome. Rheumatology (Oxford) 2008;47: Taheriazam A, Sadatsafavi M, Moayyeri A. Outcome predictors in nonoperative management of newly diagnosed subacromial impingement syndrome: a longitudinal study. MedGenMed 2005; 7: Bartolozzi A, Andreychik D, Ahmad S. Determinants of outcome in the treatment of rotator cuff disease. Clin Orthop Relat Res 1994;(308): Coghlan JA, Buchbinder R, Green S, Johnston RV, Bell SN. Surgery for rotator cuff disease. Cochrane Database Syst Rev Jan 23;(1):CD Furlan AD, Pennick V, Bombardier C, van Tulder M; Editorial Board, Cochrane Back Review Group updated method guidelines for systematic reviews in the Cochrane Back Review Group. Spine (Phila Pa 1976) 2009;34: van Tulder M, Furlan A, Bombardier C, Bouter L. Updated method guidelines for systematic reviews in the cochrane collaboration back review group. Spine (Phila Pa 1976) 2003;28: Rahme H, Solem-Bertoft E, Westerberg CE, Lundberg E, Sörensen S, Hilding S. The subacromial impingement syndrome. A study of results of treatment with special emphasis on predictive factors and pain-generating mechanisms. Scand J Rehabil Med 1998;30: Brox JI, Staff PH, Ljunggren AE, Brevik JI. Arthroscopic surgery compared with supervised exercises in patients with rotator cuff disease (stage II impingement syndrome). BMJ 1993;307: Haahr JP, Østergaard S, Dalsgaard J, et al. Exercises versus arthroscopic decompression in patients with subacromial impingement: a randomised, controlled study in 90 cases with a one year follow up. Ann Rheum Dis 2005;64: Husby T, Haugstvedt JR, Brandt M, Holm I, Steen H. Open versus arthroscopic subacromial decompression: a prospective, randomized study of 34 patients followed for 8 years. Acta Orthop Scand 2003;74: T Jonck L, Lysens R, De Smet L, et al. Open versus arthroscopic subacromial decompression: analysis of one-year results. Physiother Res Int 1997;2: Sachs RA, Stone ML, Devine S. Open vs. arthroscopic acromioplasty: a prospective, randomized study. Arthroscopy 1994;10: Iversen T, Reikeras O, Solem OI. [Acromion resection for shoulder impingement syndrome. Results after an open and a percutaneous surgical method] [Norwegian]. Tidsskr Nor Laegeforen 1996;116: Spangehl MJ, Hawkins RH, McCormack RG, Loomer RL. Arthroscopic versus open acromioplasty: a prospective, randomized, blinded study. J Shoulder Elbow Surg 2002;11: Ingvarrson T, Hagglund G, Johnsson R. Anterior acromioplasty. A comparison of two techniques. Int Orthop 1996;20: Rubenthaler F, Ludwig J, Wiese M, Wittenberg RH. Prospective randomized surgical treatments for calcifying tendinopathy. Clin Orthop Relat Res 2003;(410): Murphy MA, Maze NM, Boyd JL, Quick DC, Buss DD. Costbenefit comparison: holmium laser versus electrocautery in arthroscopic acromioplasty. J Shoulder Elbow Surg 1999;8: Taverna E, Battistella F, Sansone V, Perfetti C, Tasto JP. Radiofrequency-based plasma microtenotomy compared with arthroscopic subacromial decompression yields equivalent outcomes for rotator cuff tendinosis. Arthroscopy 2007;23: Everts PA, Devilee RJ, Brown Mahoney C, et al. Exogenous application of platelet-leukocyte gel during open subacromial decompression contributes to improved patient outcome. A prospective randomized double-blind study. Eur Surg Res 2008;40: Hultenheim Klintberg I, Gunnarsson AC, Styf J, Karlsson J. Early activation or a more protective regime after arthroscopic subacromial decompression--a description of clinical changes with two different physiotherapy treatment protocols--a prospective, randomized pilot study with a two-year follow-up. Clin Rehabil 2008;22: Hoe-Hansen C, Norlin R. The clinical effect of ketoprofen after arthroscopic subacromial decompression: a randomized doubleblind prospective study. Arthroscopy 1999;15: Jarvela T, Jarvela S. Long-term effect of the use of a pain pump after arthroscopic subacromial decompression. Arthroscopy 2008; 24: Lindh M, Norlin R. Arthroscopic subacromial decompression versus open acromioplasty. A two-year follow-up study. Clin Orthop Relat Res 1993(290):174-6.