Shoulder Article Review

Effects of 12 Weeks of Progressive Early Active Exercise Therapy After Surgical Rotator Cuff Repair 12 Weeks and 1-Year Results From the CUT-N-MOVE Randomized Controlled Trial Birgitte Hougs Kjær,*yz PT, PhD, S. Peter Magnusson,§|| PT, DMSci, Marius Henriksen,y{ PT, PhD, Susan Warming,y PT, PhD, Eleanor Boyle,z PhD, Michael Rindom Krogsgaard,# MD, PhD, Ali Al-Hamdani,** MD, and Birgit Juul-Kristensen,z PT, PhD Investigation performed at Copenhagen University Hospital Bispebjerg Frederiksberg and Herlev Gentofte, Copenhagen, Denmark Background: Traumatic full-thickness rotator cuff tears are typically managed surgically, followed by rehabilitation, but the load progression to reach an optimal clinical outcome during postoperative rehabilitation is unknown. Purpose: To evaluate whether there was a superior effect of 12 weeks of progressive active exercise therapy on shoulder function, pain, and quality of life compared with usual care. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Patients with surgically repaired traumatic full-thickness rotator cuff tears were recruited from 2 orthopaedic departments and randomized to progressive active exercise therapy (PR) or limited passive exercise therapy (UC [usual care]). The primary outcome was the change in the Western Ontario Rotator Cuff Index (WORC) score between groups from before surgery to 12 weeks after surgery. Secondary outcomes included changes in the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire score, pain, range of motion, and strength. Adverse events were registered during the intervention period. Results: A total of 82 patients were randomized to the PR (n = 41) or UC (n = 41) group. All 82 patients (100%) participated in the 12-week assessment and 79 in the 1-year follow-up. At 12 weeks, there was no significant difference between the groups in the change in the WORC score from baseline adjusted for age, sex, and center (physical symptoms: P = .834; sports and recreation: P = .723; work: P = .541; lifestyle: P = .508; emotions: P = .568). Additionally, there was no between-group difference for the secondary outcomes including the WORC score at 1 year and the DASH score, pain, range of motion, and strength at 12 weeks and 1 year. Both groups showed significant improvements over time in all outcomes. In total, there were 13 retears (16%) at 1-year follow-up: 6 in the PR group and 7 in the UC group. Conclusion: PR did not result in superior patient-reported and objective outcomes compared with UC at either short- or longterm follow-up (12 weeks and 1 year). Registration: NCT02969135 (ClinicalTrials.gov identifier) Keywords: randomized controlled trial; traumatic rotator cuff tear; shoulder surgery; exercise therapy; postoperative rehabilitation age.44 RC tears arise because of trauma or degeneration.34 The predominant symptoms are pain and loss of strength during arm elevation, resulting in functional disability.17,53 Early surgical repair of traumatic RC tears is recommended for full- or partial-thickness tears larger than 50% of the transversal or longitudinal tendon size.15,42,47 The rationale for early surgery is to preserve tissue quality and mobility while minimizing tear retraction and muscle atrophy to optimize functional outcomes and structural healing.13,14,51 According to Danish national guidelines, it is considered good practice to offer patients postoperative rehabilitation.8 Rotator cuff (RC) tears are common in the general population, with a prevalence of 11% to 13% in people in their fifth decade and increasing up to 50% in those in their eighth decade.55 Overall, 50% of all tears in patients in their fifth decade are symptomatic, and this proportion decreases with advancing The American Journal of Sports Medicine 2021;49(2):321–331 DOI: 10.1177/0363546520983823 Ó 2021 The Author(s) 321 322 Kjær et al Based on biomechanical studies, early immobilization (4-6 weeks) is suggested postoperatively to avoid gap formation negatively affecting tendon-to-bone healing.18,46 During this period, prescribed rehabilitation often consists of passive (not active) motion of the shoulder to reduce stiffness.33,35 There is better range of motion (ROM) at 3 to 6 months and at 12 months after early passive motion immediately postoperatively compared with immobilization.21 In addition, the retear rate is not increased after early passive motion compared with immobilization.6,32 It remains unknown if a well-structured progressive postoperative rehabilitation protocol may provide a clinically meaningful improvement in ROM while not increasing the risk of adverse events. Some evidence indicates that early active motion may result in greater retear rates, particularly in shoulders with larger tear sizes.2,19 Biologically, healing is best obtained by gradually increasing loads on the tissue and rest between treatment sessions.23 However, there exist only a few small randomized controlled trials (RCTs) and uncontrolled studies of early active movement with gradually increasing loads, and the results are divergent.12,30,41,48 There is a need for high-quality adequately powered trials evaluating the patient-reported outcomes and biomechanical effects of early versus delayed active ROM on shoulder function after RC repair.31 On the basis of the aforementioned limited evidence, we hypothesized that patients who receive 12 weeks of progressive active exercise therapy (PR) would benefit more with respect to improved shoulder function, pain reduction, and quality of life than those receiving passive exercise therapy (UC [usual care]). The primary aim of this trial was to evaluate whether there was a superior effect of a 12-week early progressive rehabilitation program on shoulder function compared with usual care in patients after the surgical treatment of RC tears. Secondary aims included the effects on shoulder pain, ROM, and muscle strength. METHODS Study Design The study (CUT-N-MOVE) was designed as a 2-center, randomized, controlled, outcome assessor–blinded superiority trial, with a 2-group parallel design comparing PR with UC. The primary endpoint was 12 weeks after surgery, and the secondary endpoint was 1 year after surgery. The American Journal of Sports Medicine Details of the trial protocol have been published in a previous study.29 Participants, Settings, and Locations Between March 2017 and May 2019, participants were recruited from 2 orthopaedic departments in the Capital Region of Denmark: Copenhagen University Hospital Bispebjerg Frederiksberg and Herlev Gentofte. Eligible patients were adults aged a minimum of 18 years with a clinical diagnosis of a traumatic full-thickness RC tear involving the supraspinatus tendon (full thickness and width) verified by arthroscopic surgery and repairable by surgery. A traumatic RC tear was defined by ‘‘an acute tear in patients who were previously asymptomatic and experienced sudden onset of symptoms and signs after a traumatic event e.g. fall or trauma to an abducted, externally rotated arm.’’4 Patients were excluded if they had previous shoulder surgery (including the ipsilateral glenohumeral joint, acromioclavicular joint, and thoracoscapular joint); had a clinical diagnosis of glenohumeral osteoarthritis, rheumatoid arthritis, or periarthrosis; were unable to speak or read Danish; or had other conditions that made them unsuitable for participation. Postoperative Rehabilitation Interventions The rehabilitation intervention was conducted at physical therapy departments by 10 orthopaedic physical therapists. Based on best evidence from previous studies, the postoperative training program was developed by the principal investigator (B.H.K.) and 2 clinical physical therapists specialized in orthopaedic shoulder rehabilitation in collaboration with patients who underwent surgery for a traumatic fullthickness RC tear. The PR group started loading (assisted active ROM and active ROM) at week 2, while this was introduced in the UC group at week 6. The PR group attended individual physical therapist–supervised exercise therapy 3 times weekly, supplemented with recommended daily home exercises (weeks 2, 3, 4, and 5), and the UC group attended individual physical therapist–supervised exercise therapy once a week, supplemented with recommended daily home exercises (weeks 2, 3, 4, and 5). From weeks 6 to 12, both groups received physical therapist–supervised exercise therapy twice a week (individually or in small groups) in addition to the unsupervised daily home exercises. The shoulder-specific exercises were progressed through different phases defined by levels of shoulder function, as previously described.29 *Address correspondence to Birgitte Hougs Kjær, PT, PhD, Department of Physical and Occupational Therapy, Copenhagen University Hospital Bispebjerg Frederiksberg, Bispebjerg Bakke 23, Copenhagen NV, DK-2400, Denmark (email: [email protected]) (Twitter: @BHougsKjaer). y Department of Physical and Occupational Therapy, Copenhagen University Hospital Bispebjerg Frederiksberg, Copenhagen, Denmark. z Department of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark. § Institute of Sports Medicine, Department of Orthopaedic Surgery M, Copenhagen University Hospital Bispebjerg Frederiksberg, Copenhagen, Denmark. || Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. { The Parker Institute, Copenhagen University Hospital Bispebjerg Frederiksberg, Copenhagen, Denmark. # Section for Sports Traumatology, Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg Frederiksberg, Copenhagen, Denmark. **Shoulder-Elbow Unit, Department of Orthopaedic Surgery, Copenhagen University Hospital Herlev Gentofte, Copenhagen, Denmark. Submitted November 18, 2019; accepted October 26, 2020. The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto. AJSM Vol. 49, No. 2, 2021 Physical Therapy After Rotator Cuff Repair 323 Outcomes Data Collection The primary outcome was the change in the Western Ontario Rotator Cuff Index (WORC) score from baseline to 12 weeks postoperatively. The WORC is a self-administered questionnaire developed to measure pain, functional activity level, and health-related quality of life in patients with RC disease.26 The WORC was developed with help from patients with various RC conditions, including total tears, and consists of 21 items in 5 domains: physical symptoms (6 items), sports and recreation (4 items), work (4 items), lifestyle (4 items), and emotions (3 items). Each question is scored on a 100-mm visual analog scale, with higher scores indicating larger problems. A percentage score ranging from 0 (worst possible) to 100 (best possible) was used as advocated by its developers.26,38 The crossculturally translated Danish version, which is valid, reliable, and responsive, was used.5 Secondary outcomes were changes in the WORC score at 6 weeks and 1 year. Additionally, secondary patientreported outcomes assessed at 6 weeks, 12 weeks, and 1 year included changes in the Disabilities of the Arm, Shoulder and Hand (DASH) score, a semigeneric upper extremity questionnaire20,37; Global Rating Scale (GRS) score, which provided a general impression of recovery from baseline to 6 and 12 weeks postoperatively3,9,49; and Numeric Pain Rating Scale (NPRS) score in which patients were asked about pain at rest, pain during general activity/ function, and maximum pain experienced during the past 24 hours.11,45 Secondary clinical outcomes included changes in active and passive ROM measured by a digital inclinometer at 6 weeks, 12 weeks, and 1 year as well as strength (maximum voluntary isometric contraction) measured by a dynamometer (IsoForce EVO2; Chiroform ApS) at 12 weeks and 1 year. Registered patient data included age, sex, tendon(s) involved, dominant side, employment, and patient-reported days of sick leave from work. The condition of the operated tendon was assessed using a prespecified protocol by a radiologist, rheumatologist, or orthopaedic surgeon at 6 weeks and the primary investigator at 1 year (all 4 experienced with shoulder ultrasound scanning and blinded to the intervention) using an Ascendus (Hitachi) ultrasound scanner. A retear was defined as total separation of the repaired supraspinatus tendon from bone. Intervention adherence and attendance during the 12 weeks were recorded in exercise logbooks for both groups. The patients were asked to report completed home-based exercise sessions and the reason for not performing a planned exercise (pain or other reasons). Supervision of the subsequent home exercises at the commencement of every session was performed to facilitate program adherence. Reinforcement techniques were used, with the physical therapist giving positive feedback and appraising/ commending patients for their efforts. Satisfactory intervention adherence was defined as having performed at least 75% of the scheduled rehabilitation program whether at on-site supervised sessions or unsupervised (homebased) sessions as individually tailored by the physical therapist.29 Orthopaedic surgeons performed the initial screening and referred patients awaiting surgery to the principal investigator, who performed the final eligibility assessment, provided the patients with detailed information about the study, and asked patients for consent to participate in the study. After obtaining written consent, a baseline assessment was performed between 1 and 14 days before surgery. Patients who had a total/full-thickness supraspinatus tear, confirmed by the orthopaedic surgeon during surgery, that was repaired were included in the study and electronically randomized to PR or UC rehabilitation. Sample Size and Power Calculations A sample size calculation was performed a priori on the basis of the WORC physical symptoms subscore at 12 weeks,10 showing that 41 patients were required per group to be able to establish a clinically significant mean difference of 12 points with a common SD of 20 (0-100 scale),10,27 80% power, and a significance level of 5%. To account for dropouts, we planned to include a total of 50 per group; however, as all included participants attended the 12week follow-up visit (primary endpoint), recruitment was stopped when the required number was reached (2 times 41 patients). Randomization and Allocation Concealment Participants were randomized (1:1) to receive either PR or UC. To control for potential imbalance in the randomization, stratification (age, sex, and center) and blocking were employed. Randomization to 1 of 2 treatment arms was computer generated based on permuted random blocks of variable sizes (3-6 in each block) using the Procordo Research Platform (www.procordo.com). Randomization was performed after baseline tests and surgery, and allocation (based on randomization) was performed by a person who was not involved in the current project. Blinding Baseline examinations were performed before group allocation. All postoperative examinations were performed blinded to group allocation by the principal investigator or 2 physical therapists trained as outcome assessors. The participants were instructed not to reveal group allocation during assessments. As this was an ‘‘open-label’’ trial, the health professionals administering the interventions and the participants were not blinded to treatment allocation. The patients were informed that 2 strategies were being compared in the study, but they were blinded to the hypotheses. Statistical Analysis The primary analysis was performed as an assessment of the between-group difference in the change in the WORC 324 Kjær et al score after 12 weeks in the intention-to-treat (ITT) population. This was defined as all randomized participants, irrespective of compliance, crossover, or withdrawal. Patients were considered randomized as soon as the training group was assigned according to the allocation sequence. Missing follow-up data were imputed using the baseline observation carried forward approach. The per-protocol (PP) population was defined as the as-observed participants who had attended at least 75% of the scheduled rehabilitation appointments. Sensitivity analyses were performed for detecting differences in demographics and baseline data between participants lost to follow-up and those from the complete data set using the Fisher exact test or t test, depending on the variable tested. All data were tested for normal distribution. Analysis of the primary outcome was performed by repeated-measures analysis of covariance, with the change in the WORC score as the dependent variable and group (2 levels), time (2 levels; 6 and 12 weeks), and baseline WORC score as independent variables and confounders (age, sex, and center). Secondary outcomes were analyzed with analysis of covariance, with DASH score, pain, strength, and ROM as dependent variables and the same independent variables and confounders as in the analysis of the primary outcome. The GRS score and adverse events (eg, retears) were analyzed with multiple logistic regression analysis, with the same confounders as in the analyses of the primary and secondary outcomes. All ITT analyses were performed blinded to group allocation. An external statistical consultant (E.B.) performed the analysis on the primary outcome data blinded. All statistical tests were 2-sided, with P .05 considered statistically significant (using 95% CIs). All data analyses were carried out according to the pre-established analysis plan28 and performed using SPSS software (Version 25.0; IBM). Ethics and Registration The study was approved by the Health Research Study Board for the Capital Region of Denmark (H-16033995) and by the Danish Data Protection Agency (2012-580004), and it was registered on ClinicalTrials.gov (NCT02969135). The study was conducted in accordance with the Declaration of Helsinki.54 Informed consent was obtained from all patients. Before group allocation was unblinded, a consensus agreement on the interpretation of the primary outcome was signed by all authors.27 RESULTS Between March 2017 and May 2019, a total of 326 patients from 2 orthopaedic departments were screened for eligibility. Of these, 126 patients fulfilled the preoperative eligibility criteria and signed informed consent forms to participate. There were 44 participants who did not meet postoperative inclusion criteria and were excluded (Figure 1). Thus, 82 patients were included in the study, and 41 were randomized to the PR group and 41 to the UC group (Figure 1). The 2 groups were comparable at baseline (Table 1). The American Journal of Sports Medicine TABLE 1 Demographics and Baseline Dataa PR Group (n = 41) Age, y 59.0 6 8.6 Male sex 29 (70.7) Height, cm 177.0 6 8.7 Weight, kg 89.0 6 19.4 28.2 6 5.2 Body mass index, kg/m2 Side, right/left, n 28/13 Dominant side affected 27 (65.9) Employment Manual laborer 13 (31.7) Office worker 9 (22.0) Retired 19 (46.3) No. of injured tendons 1 tendon 29 (70.7) 2 tendons 10 (24.4) 3 tendons 2 (4.9) Tendons involved Supraspinatus 41 (100.0) Infraspinatus 11 (26.8) Subscapularis 3 (7.3) WORC (0-100; 0 = most disabled) Physical symptoms 54.0 6 19.6 Sports and recreation 35.5 6 24.7 Work 27.4 6 20.2 Lifestyle 41.2 6 26.7 Emotions 41.7 6 25.6 DASH (0-100; 100 = most disabled) Total 43.4 6 18.4 Workb 45.0 6 32.5 Leisure time/hobbyc 72.5 6 27.5 NPRS (0-10; 10 = most pain) Pain at rest (now) 3.9 6 2.6 Pain during activity (now) 6.0 6 2.7 Worst pain (past 24 h) 6.8 6 2.6 UC Group (n = 41) 61.0 6 8.0 25 (61.0) 176.0 6 10.0 86.0 6 21.1 27.8 6 5.0 25/16 27 (65.9) 19 (46.3) 9 (22.0) 13 (31.7) 22 (53.7) 16 (39.0) 3 (7.3) 41 (100.0) 15 (36.6) 7 (17.1) 49.3 6 18.2 28.6 6 21.3 22.6 6 19.8 39.9 6 23.7 43.0 6 29.7 44.7 6 14.6 45.0 6 32.3 74.0 6 25.8 4.0 6 2.6 6.7 6 2.5 7.2 6 2.1 a Data are reported as mean 6 SD or n (%) unless otherwise indicated. DASH, Disabilities of the Arm, Shoulder and Hand; NPRS, Numeric Pain Rating Scale; PR, progressive; UC, usual care; WORC, Western Ontario Rotator Cuff Index. b Optional module (voluntarily answered): n = 25 for PR and n = 30 for UC. c Optional module (voluntarily answered): n = 15 for PR and n = 19 for UC. The PP population consisted of 53 patients (25 PR; 28 UC). There was no between-group difference in the number of patients who were compliant. The demographics and clinical characteristics of the PP population were comparable with those of the ITT population (Appendix Table A1, available in the online version of this article). The interval between trauma and surgery was 3 to 28 weeks. Overall, 50% underwent isolated arthroscopic RC repair, and 50% underwent deltoid split repair. The double-row technique was used in 71 patients and the single-row technique in 11 patients. A total of 8 surgeons performed the operative procedures during the 2-year period. Efficacy Analysis For the primary outcome at 12 weeks, there was no significant difference between the groups in the change in the WORC score from baseline adjusted for age, sex, and center (physical symptoms: P = .834; sports and recreation: P = .723; work: P = .541; lifestyle: P = .508; emotions: P = AJSM Vol. 49, No. 2, 2021 Physical Therapy After Rotator Cuff Repair Screening for eligibility (n = 326) Enrollment Surgery (n = 126) Randomized (n = 82) 325 Excluded (n = 200) x Not meeting inclusion criteria (n = 166) (partial tear, not traumatic, not involving supraspinatus) x Declined to participate (n = 34) Excluded after surgery (n = 44) x Not repairable (n = 11) x Partial tear (n = 28) x Other reasons (n = 5) (special regime/ immobilization for 6 weeks, bone avulsion) Allocation Allocated to intervention (PR) (n = 41) x Received allocated intervention (n = 41) Allocated to care as usual (UC) (n = 41) x Received allocated intervention (n = 41) 6 weeks Follow-up Participated (n = 40) x Did not attend follow up (n = 1) Participated (n = 41) 12 weeks Primary endpoint Lost to follow-up (n = 0) x Discontinued intervention (n = 2) Lost to follow-up (n = 0) x Discontinued intervention (n = 1) (infection with revision surgery (n = 1)) (re-tear with revision surgery (n = 1), biceps dislocation with tenodesis surgery (n = 1)) Analysis Analyzed PR (n = 41) Lost to follow-up (n = 3) x Unable to contact (n = 2) Analyzed UC (n = 41) 1 year Follow-up Lost to follow-up (n = 0) (deceased due to chronic lung disease (n = 1), deceased due to congenital heart disease) x Unable to participate (n = 1) (surgery with a delta prosthesis exactly one-year post surgery) Analysis Analyzed PR (n = 41) Analyzed UC (n = 41) Figure 1. Flowchart of patients with traumatic rotator cuff tears in the intention-to-treat (ITT) population. All patients underwent an allocated intervention, meaning that a total of 82 patients (PR: n = 41; UC: n = 41) constituted the as observed population for the primary outcome. PR, progressive group; UC, usual care group. .568) (Table 2). Furthermore, no significant between-group differences were found for the secondary outcomes (DASH score, pain, ROM, and strength) at 6 and 12 weeks. An exception was the change from baseline in active scaption ROM at 6 weeks of 13.8° (95% CI, 0.2°-27.4°; P = .046) in favor of the PR group, which did not remain significant at 12 weeks (Table 2). Both groups had significant and clinically relevant improvements at 12 weeks in the WORC score (Figure 2) and pain (Table 2). The sensitivity analyses on the PP population (25 PR; 28 UC) showed no group difference in compliance and that the PP population did not differ from the ITT population, and the efficacy results of the PP analyses confirmed the ITT results (Appendix Tables A1 and A2, available online). At 1-year follow-up, there was no significant difference between the groups in the change in the WORC score from baseline adjusted for age, sex, and center (Table 3). Furthermore, no significant between-group differences 326 Kjær et al The American Journal of Sports Medicine Figure 2. Western Ontario Rotator Cuff Index (WORC) scores at baseline and 6 and 12 weeks postoperatively. The graphs illustrate the results from the intention-to-treat population, with data points representing means and error bars indicating 95% CIs. PR, progressive group; UC, usual care group. were found for the secondary outcomes (DASH score, pain, ROM, and strength) at 1-year follow-up. Patients in both groups had significant and clinically relevant improvements at 1-year follow-up in the WORC score, DASH score, pain, ROM, and strength, and about 80% of the patients experienced a general improvement (Table 3). The majority (70%) of the patients had returned to work at 12 weeks (PR: 65 6 50 sick days; UC: 60 6 50 sick days). After 1 year, 85% of the patients had returned to work. At 1-year follow-up, 4 additional patients had experienced tendon retears. In total, 13 patients (16%) were registered with tendon retears by ultrasound at 1 year postoperatively, 6 (15%) in the PR group and 7 (17%) in the UC group, with no statistical difference between the groups (P = .881). Overall, 3 retears occurred in a single tendon (PR: n = 2; UC: n = 1), and 10 retears (PR: n = 4; UC: n = 6) occurred in multiple tendons (2 tendons), with a statistically significant difference in the proportions between the groups (P = .002). Adverse Events At 12 weeks, 11 patients had experienced adverse events, of which there were 9 retears (11%) observed by ultrasound at 6 weeks postoperatively: 6 (15%) in the PR group and 3 (7%) in the UC group, which was not statistically different (P = .295). One of the 9 retears (occurring in the UC group) underwent revision surgery at week 8. The remaining 8 patients with retears observed by ultrasound at 6 weeks postoperatively continued their scheduled rehabilitation protocol. In addition to the retears, 1 patient (belonging to the PR group) developed an infection with initial revision surgery at week 6, and 1 patient (belonging to the UC group) had a medial biceps dislocation with tenodesis surgery at week 10 (Figure 1). DISCUSSION PR did not result in superior short- or long-term effects in the primary outcome (WORC score) compared with UC after 12 weeks of postoperative rehabilitation after surgical RC repair. Neither was there any superior effect of PR in any secondary outcomes (subjective as well as objective). The lack of difference between the 2 interventions may relate to the loading protocols of the interventions. While our PR group performed an exercise program with early supervised active exercise therapy (early loading) 3 times a week from day 8 (plus home exercises the remaining 4 days a week), the UC group performed an exercise program AJSM Vol. 49, No. 2, 2021 Physical Therapy After Rotator Cuff Repair 327 TABLE 2 Changes From Baseline to 6 and 12 Weeks Postoperatively for Primary and Secondary Outcomesa Baseline to 6 Weeks Within-Group Change WORC Physical symptoms Sports and recreation Work Lifestyle Emotions DASH Total Workc Leisure time/hobbyd NPRS Pain at rest (now) Pain during activity (now) Worst pain (past 24 h) GRS (–7 to 7) Improved (1-7), n (%) ROM, deg Scaption Passive Active External rotation Passive Active Internal rotation Passive Active Strength (MVIC), Nm Scaption External rotation Internal rotation Baseline to 12 Weeks Adjustedb Within-Group Change Adjustedb PR, Mean Change (SE) UC, Mean Change (SE) Between-Group Difference (95% CI) P Value PR, Mean Change (SE) UC, Mean Change (SE) Between-Group Difference (95% CI) P Value 10.9 (2.4) 24.9 (2.4) –3.5 (2.3) 2.1 (2.8) 9.7 (3.5) 8.1 (2.4) 23.4 (2.4) 26.8 (2.3) 2.5 (2.8) 9.0 (3.5) 2.8 (24.1 to 9.7) 1.4 (25.6 to 8.4) 3.3 (23.2 to 9.7) 0.4 (27.4 to 8.2) 0.7 (29.1 to 10.6) .421 .687 .320 .916 .882 19.0 (2.5) 11.5 (2.8) 16.6 (3.0) 22.5 (3.2) 20.1 (3.6) 18.2 (2.5) 10.1 (2.8) 19.2 (3.0) 25.6 (3.2) 23.0 (3.6) 0.8 (26.4 to 7.9) 1.4 (26.5 to 9.3) –2.7 (25.9 to 11.1) –3.1 (26.1 to 12.2) –2.9 (27.2 to 13.0) .834 .723 .541 .508 .568 2.1 (2.2) 13.9 (8.4) 17.6 (6.1) 5.2 (2.2) 6.7 (6.8) 22.0 (4.2) –3.1 (29.4 to 3.2) 7.2 (–15.8 to 30.3) –4.4 (220.7 to 11.9) .331 .523 .577 –8.3 (2.8) –9.6 (6.7) 3.5 (9.3) –3.4 (2.8) –7.1 (5.4) –12.0 (6.4) –5.0 (212.9 to 3.0) –2.5 (220.9 to 15.9) 15.5 (29.4 to 40.4) .212 .782 .204 –2.0 (0.3) –2.2 (0.3) –2.1 (0.4) –2.2 (0.3) –2.6 (0.3) –2.2 (0.4) 0.2 (–0.5 to 1.0) 0.4 (20.4 to 1.3) 0.1 (20.9 to 1.1) .542 .328 .798 –2.7 (0.2) –3.1 (0.3) –3.0 (0.4) –3.1 (0.2) –3.9 (0.3) –3.5 (0.4) –0.4 (20.1 to 0.9) 0.8 (0.0 to 1.6) 0.6 (20.5 to 1.6) .108 .060 .290 9 (22.0) 15 (36.6) –15.0 (26.1 to 41.5) .145 30 (73.2) 25 (61.0) 12.0 (–36.8 to 9.2) .240 –14.7 (3.6) –10.4 (4.8) –15.6 (3.2) –24.2 (4.8) 0.8 (–9.2 to 10.8) 13.8 (0.2 to 27.4) .871 .046e 7.0 (3.0) 21.1 (4.3) 3.2 (3.0) 12.0 (4.2) 3.8 (–4.6 to 12.2) 9.1 (22.9 to 21.1) .372 .136 –15.3 (2.7) –14.9 (2.8) –17.2 (2.7) –16.8 (2.8) 1.9 (–5.8 to 9.6) 1.9 (26.1 to 9.8) .627 .639 1.5 (3.0) 0.1 (2.8) 1.7 (3.0) 1.4 (2.8) –0.2 (28.7 to 8.3) 1.3 (29.2 to 6.6) .966 .744 –7.6 (1.9) –5.0 (1.9) –5.8 (1.9) –4.4 (1.9) –1.9 (27.3 to 3.5) 20.7 (26.0 to 4.7) .486 .809 –2.5 (1.6) –1.0 (1.7) 0.6 (1.6) 2.4 (1.7) –3.1 (27.7 to 1.6) –3.5 (28.3 to 1.4) .190 .162 7.4 (4.3) 15.4 (3.2) 6.7 (5.0) 14.3 (4.2) 10.7 (3.1) 11.9 (4.9) 26.9 (218.9 to 5.2) 4.7 (24.2 to 14.0) –5.2 (219.2 to 8.8) .259 .293 .462 a DASH, Disabilities of the Arm, Shoulder and Hand; GRS, Global Rating Scale; MVIC, maximum voluntary isometric contraction; NPRS, Numeric Pain Rating Scale; PR, progressive; ROM, range of motion; UC, usual care; WORC, Western Ontario Rotator Cuff Index. b Adjusted for baseline values, age, sex, and center. c Optional module (voluntarily answered): n = 25 for PR and n = 30 for UC. d Optional module (voluntarily answered): n = 15 for PR and n = 19 for UC. e Statistically significant. with early supervised passive exercise therapy (delayed loading) once a week starting from day 8 (plus home exercises the remaining 6 days a week). Although loading is important for optimal tendon healing,23 to our knowledge, only 2 RCT studies12,41 and 2 prospective randomized pilot studies30,48 have focused on loading of the exercise intervention, and the results are divergent. In line with the current results, 2 of the studies found no difference in self-reported function (WORC score, Constant-Murley score, and pain), active ROM, and muscle strength between early active loading and delayed active loading.30,41 In contrast, the other 2 studies found superior short-term effects of early active loading versus delayed active loading on self-reported function (DASH score, Constant-Murley score, and pain)12,48; however, these studies were of inferior quality and had a high risk of bias. Further, none of the 4 studies reported any difference in retear rates between groups.12,30,41,48 Unfortunately, an overall comparison between studies is difficult because timing and loading vary to a large extent among studies.40 The rest of the previous studies concerning postoperative rehabilitation are focused on timing of the exercise intervention (and not loading), and they have typically compared an early passive ROM intervention versus a 6week delayed intervention,1,8,24,25,36 which complicates a comparison with the present study. The present study showed an overall retear rate of 16% at 1 year, which is similar to that of previous studies.1,7,12,24,25,36,41 Even though a comparison between studies is difficult, as the time point for the evaluation of repair integrity and the time course of healing or failure vary from 6 months to 2 years postoperatively, the retear rate in the present study was not regarded as unusual or as a warning of an adverse effect of one of the regimens. The present low number of retears precludes a robust statistical analysis between the groups, but it is noteworthy that in the PR group, there were twice as many retears observed by ultrasound at 6 weeks postoperatively as in the UC group. However, this difference was offset by the 1-year observations, indicating that repair that would fail 328 Kjær et al The American Journal of Sports Medicine TABLE 3 Changes From Baseline to 1-Year Follow-up for Primary and Secondary Outcomesa Baseline to 1 y Adjustedb Within-Group Change WORC Physical symptoms Sports and recreation Work Lifestyle Emotions DASH Total Workc Leisure time/hobbyd NPRS Pain at rest (now) Pain during activity (now) Worst pain (past 24 h) GRS (–7 to 7) Improved (1-7), n (%) ROM,e deg Scaption Passive Active External rotation Passive Active Internal rotation Passive Active Strength (MVIC),e Nm Scaption External rotation Internal rotation PR, Mean Change (SE) UC, Mean Change (SE) Between-Group Difference (95% CI) P Value 26.2 (3.3) 33.3 (4.0) 36.4 (4.8) 35.2 (3.6) 31.4 (4.2) 25.2 (3.3) 32.9 (4.0) 41.2 (4.8) 40.0 (3.6) 35.4 (4.2) 1.0 (28.4 to 10.5) 0.4 (211.0 to 11.9) 24.8 (218.4 to 8.8) –4.7 (215.0 to 5.5) –4.0 (216.0 to 7.9) .827 .939 .482 .362 .505 –13.8 (3.5) –26.3 (4.7) –42.3 (6.4) –18.2 (3.5) –28.0 (4.2) –58.8 (5.3) –4.6 (25.2 to 14.4) 1.6 (–11.4 to 14.7) 16.5 (–0.9 to 33.9) .355 .800 .061 –3.0 (0.2) –3.7 (0.3) –4.4 (0.4) –3.0 (0.2) –4.1 (0.3) –4.7 (0.4) 0.0 (–0.7 to 0.7) –0.3 (20.6 to 1.3) –0.3 (20.7 to 1.4) .957 .497 .523 32 (78.0) 34 (82.9) 2.0 (–22.0 to 12.0) .577 19.6 (2.6) 39.6 (3.9) 21.0 (2.6) 38.3 (3.9) –1.5 (29.0 to 6.0) 1.3 (–9.8 to 12.3) .695 .822 18.1 (2.7) 14.6 (2.6) 22.7 (2.7) 18.9 (2.6) –4.6 (212.1 to 2.9) –4.4 (–11.7 to 3.2) .226 .265 3.4 (1.6) 5.8 (1.6) 5.3 (1.6) 8.9 (1.6) –1.9 (26.3 to 2.5) –3.1 (27.5 to 1.3) .394 .165 23.1 (4.1) 30.0 (3.9) 28.0 (4.3) 34.2 (4.1) 30.6 (3.9) 22.9 (4.3) 211.1 (222.8 to 20.5) 20.7 (211.7 to 10.3) 5.1 (27.2 to 17.3) .061 .904 .410 a DASH, Disabilities of the Arm, Shoulder and Hand; GRS, Global Rating Scale; MVIC, maximum voluntary isometric contraction; NPRS, Numeric Pain Rating Scale; PR, progressive; ROM, range of motion; UC, usual care; WORC, Western Ontario Rotator Cuff Index. b Adjusted for baseline values, age, sex, and center. c Optional module (voluntarily answered): n = 20 for PR and n = 27 for UC. d Optional module (voluntarily answered): n = 15 for PR and n = 19 for UC. e n = 37 for PR and n = 37 for UC. anyhow would be easier to identify early in the PR group and show later in the UC group when loading had been introduced in rehabilitation. In the current study, the WORC score was selected as the primary outcome to be as specific as possible in relation to the selected population. In contrast, the 2 aforementioned studies focusing on loading that did find a superior shortterm effect of increased loading used other self-reported outcomes, such as the DASH score,12 which is a semigeneric upper extremity questionnaire, and the Constant-Murley score,48 which is a mixed subjective and objective score. However, in line with the current study results, the only previous RCT study focusing on loading that did use the WORC score as the primary outcome also found no difference between groups at the primary endpoint (6 months).41 Patients with RC conditions were involved in the development of the WORC, which makes this questionnaire valid for our patient group. One WORC subdomain may not represent all self-perceived aspects of the condition; however, we found no difference between groups on any of the subdomains (physical symptoms, sports and recreation, work, lifestyle, and emotions), which is in line with the previous study reporting on the WORC.41 Further, our results on the secondary self-reported outcomes of the DASH and NPRS scores also showed no group difference, supporting the results of the primary outcome. What may be the reasons for the lack of difference? It is possible that the discrepancy in intervention loading between the groups was insufficient to substantially influence subjective and objective shoulder function and the natural healing process after surgical repair.22,23,35,43,52 Furthermore, because surgical repair and postoperative physical therapy traditionally are an integrated package for patients with RC tears in our geographic region, it is AJSM Vol. 49, No. 2, 2021 difficult to differentiate between the effects of surgery and postoperative physical therapy rehabilitation. It would require a third arm in an RCT with no postoperative physical therapy rehabilitation to investigate the natural healing process after surgery alone. Compared with other studies using populations of nontraumatic/traumatic and partial-/full-thickness tears,1,7,12,24,25,36,41 the present population of traumatic full-thickness tears of 1 to 3 tendons may have had a more extensively damaged RC.16,39 This could have resulted in difficulties in completing the PR intervention.29 However, the compliance assessment showed no difference between the groups. In contrast to our study, all aforementioned previous RCT studies1,7,12,24,25,36,41 failed to document patient compliance or adherence to protocols, which makes a comparison impossible. Clinically Relevant Improvements The similarity in efficacy between the groups with narrow confidence intervals and sensitivity analyses supporting the ITT results implies equivalent efficacy. Furthermore, group improvements from baseline to 12 weeks postoperatively exceeded the minimal clinically important difference (MCID) for both the WORC (MCID, 11.7)26 and the NPRS (MCID, 2)11 and from baseline to 1 year postoperatively for the WORC, the DASH (MCID, 10.2-11.7),37,50 and pain (NPRS). This finding is furthermore consistent with the current patient-perceived global effect (GRS) in which 73% in the PR group and 61% in the UC group felt an overall improvement from baseline to 12 weeks and 78% in the PR group and 83% in the UC group felt an overall improvement from baseline to 1 year. Limitations It could be a limitation that the completion of home-based exercises was self-reported and influenced by reporting bias. However, both the home-based exercises and the supervised on-site exercise therapy were included in the compliance calculations for a given patient, and patients were only considered compliant if above 75% on both the home-based and the on-site exercise programs. However, as we have no reason to believe that there were group differences in such potential reporting bias and that compliance did not differ (PR: 61%; UC: 68%; PP population), reporting bias is not likely to have influenced the data. Another limitation is the lack of double blinding, which may affect patient expectations; however, the patients were not informed about the study hypotheses a priori. Strengths The strengths are the rigorous methodological study design including blinding of examiners, publication of a statistical analysis plan before data handling, blinded outcome analysis performed by an external statistician, publication of a consensus agreement on interpretation of the results before unblinding, and publication of a detailed Physical Therapy After Rotator Cuff Repair 329 study protocol including a standardized public exercise protocol for both intervention groups. Furthermore, the study had adequate power to detect clinically relevant improvements in disease-specific patient-reported outcomes (WORC) and pain. The randomization process stratified participants by age, sex, and center and thereby included a heterogeneous socioeconomic population recruited from a large diverse urban area, resulting in high external validity, with findings generalizable to most repairable traumatic full-thickness RC tears. In addition, patients were consecutive with a high acceptance rate (only 34 of the 160 potential participants refused to be enrolled in the study) and a high follow-up rate, and thus, the population can be regarded as representative of the recruiting area. Another strength of the trial is that we measured compliance and adherence to both the supervised on-site and the home-based exercise protocols and thereby were able to support the ITT results by sensitivity analyses. 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