Abstract
Introduction
The purpose of this cross-sectional study is to determine if the duration of symptoms influences the features seen in patients with atraumatic full thickness rotator cuff tears. Our hypothesis is that increasing duration of symptoms will correlate with more advanced findings of rotator cuff tear severity on MRI, worse shoulder outcome scores, more pain, decreased range of motion, and less strength.
Methods
450 patients with full thickness rotator cuff tears were enrolled in a prospective cohort study to assess the effectiveness of nonoperative treatment and factors predictive of success. Duration of patient symptoms were divided into four groups: ≤3 months, 4–6 months, 7–12 months, and >12 months. Data collected at patient entry into the study included: 1.) Demographic data, 2.) History and physical exam data, 3.) Radiographic imaging data, and 4.) Validated patient reported measures of shoulder status. Statistical analysis included a univariate analysis with Kruskal-Wallis test and Pearson tests to identify statistically significant differences in these features for different durations of symptoms
Results
Longer duration of symptoms does not correlate with more severe rotator cuff disease. Duration of symptoms was not related to weakness; limited range of motion; tear size; fatty atrophy; or validated patient reported outcome measures.
Conclusions
There is only a weak relationship between the duration of symptoms and features associated with rotator cuff disease.
Level of Evidence
Level III, Cross Sectional Study
Keywords: Rotator Cuff Tear, Duration of Symptoms, Cross-Sectional Study
Introduction
The patient presenting with a full thickness rotator cuff tear can have a variety of complaints including pain, weakness, functional loss, and decreased range of motion14. The prevalence of asymptomatic rotator cuff tears is high, particularly with increasing age24, 36. The factors provoking symptoms in patients with rotator cuff tears remain unknown35.
Currently, the duration of shoulder symptoms is used as an indication for the surgical treatment of full thickness rotator cuff tears10, 21, 34. In the setting of a known acute traumatic full thickness rotator cuff tear, repair within three weeks of injury has been suggested as optimal2. Repair of full thickness rotator cuff tears beyond one year of symptoms appears to have poorer results, and patients who undergo repair within three for four months of the onset of symptoms can expect a good result10, 21, 34; however this relationship between the duration of symptoms and poorer outcomes after surgery has not been demonstrated consistently5, 14, 26, 34.
Anatomically, an increased duration of a full thickness rotator cuff tear may contribute to increased tear size or fatty atrophy of rotator cuff muscle12, 30, 36. However it is not clear how these anatomic features are related to the development of symptoms.
The purpose of this cross-sectional study is to test the hypothesis that increasing duration of symptoms in patients with atraumatic full thickness rotator cuff tears will correlate with more advanced findings of rotator cuff tear severity on MRI, worse shoulder outcome scores, more pain, decreased range of motion, and less strength on initial presentation.
Materials and Methods
Study Design
Our research group is a collaborative effort comprised of 16 surgeons and research personnel representing private and academic practices from across the United States. This group met repeatedly over two years to develop research questions and align practice behaviors, by conducting systematic reviews of the literature, performing agreement studies, and developing consensus when no data was available3, 4, 16, 17, 29, 34. The first clinical study conducted by the group was a prospective cohort study evaluating physical therapy for patients with atraumatic full thickness rotator cuff tears18. There were a total of 452 patients enrolled in the study and 30 patients withdrew. However the baseline data was obtained in 11 of the 30 that withdrew leaving a final total of 433 for analysis in the current study.
Setting
Patients were enrolled in the offices of the surgeons in the involved research group.
Participants
Patients who presented with symptoms and atraumatic full thickness rotator cuff tears between the ages of 18–100 were invited to participate. Exclusion criteria included a history of acute injury (defined as a traumatic event that precipitated symptoms with 3 months of presentation), prior surgery to the shoulder, pain determined to be related to cervical or other disorders, glenohumeral osteoarthritis or inflammatory arthritis, adhesive capsulitis, fracture of the proximal humerus, known bilateral rotator cuff tears, and a history of dementia.
Variables/Data Sources
Patients who were enrolled contributed data on demographics, comorbidities27, and historical information regarding the intensity and severity of symptoms on a questionnaire form. In addition, patients completed the following validated measures of patient shoulder status: SF-1232, American Shoulder and Elbow Surgeons (ASES) Score25, Western Ontario Rotator Cuff (WORC) Index15, Single Assessment Numeric Evaluation (SANE) Score33, and the Shoulder Activity Scale7. Patients were specifically asked to define the duration of symptoms as: less than three months, between four and six months, between seven and 12 months, or greater than one year.
Physicians performed physical examinations of the patients and recorded information on areas of tenderness; active and passive range of motion measured in 10-degree increments; and strength measured using the Medical Research Council (MRC) manual muscle testing19 grades 0–5. In addition, physicians reviewed radiographs and MRI scans for each patient then graded the severity of the rotator cuff tear based on the number of tendons involved; retraction of the rotator cuff tear in the coronal plane (minimal, mid-humeral, glenohumeral, to glenoid)22; and the degree of muscle atrophy12, features found to have reasonably high inter-observer agreement in our research group29. MRI scans were obtained an average of 31 days prior to enrollment in the study.
Quantitative Variables
Quantitative variables included the categorical dependent variable of duration of symptoms (≤3 months, 4–6 months, 7–12 months, or > 1 year) and independent variables including: 1.) Demographics (age, gender, workers compensation claims, race, employment, marital status, patient expectations of treatment13, and hand dominance); 2.) History information (pain level); 3.) Physical examination findings (strength using MRC grades19, range of motion measured in 10-degree increments for various planes and rotations); 4.) Imaging findings (level of rotator cuff tear retraction, presence of superior humeral head migration, rotator cuff muscle atrophy, acromial shape, and acromiohumeral interval); and 5.) Patient reported outcome scores as described above.
Statistical Methods
The relationships between duration of symptoms and nonparametric continuous variables were evaluated using the Kruskal-Wallis test. Pearson’s chi-square test was employed to evaluate the association between duration of symptoms and categorical variables. Statistical analysis was performed with fee open source R statistical software (R Development Core Team. R: A Language and Environment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing; 2010. Available at: http://www.R-project.org/).
Results
Of the 433 patients included in the cohort, 430 patients had complete data regarding the duration of symptoms. Demographic data and its relationship to the patient’s durations of symptoms are displayed in Table 1. In the cohort 30% of patients had symptoms for ≤ 3 months, 10% had symptoms for 4–6 months, 15% had symptoms for 7–12 months, and 36% had symptom for over a year. No significant relationship exists between the duration of a patient’s symptoms and gender, race, employment, marital status, worker’s compensation, and patient expectation of treatment. There was a significant difference noted among groups with regard to age with a higher median age among those with symptoms of less than three months.
Table 1.
Duration of Symptoms Related to Demographics.
| Duration of Symptoms (Months) | ≤3 | 6–6 | 7–12 | >12 | p-value |
|---|---|---|---|---|---|
|
| |||||
| Age in Years: Median with lower and upper quartiles1 | 58 (63) 72 | 57 (60) 66 | 57 (62) 69 | 55 (60) 69 | 0.03 |
|
| |||||
| Gender (% Female)1 | 48 | 54 | 60 | 44 | 0.17 |
|
| |||||
| Worker’s Compensation (% Yes)1 | 6 | 11 | 12 | 11 | 0.52 |
|
| |||||
| Race (%)2 | 0.59 | ||||
|
| |||||
| Other | 5 | 7 | 2 | 5 | |
|
| |||||
| Black | 13 | 7 | 8 | 8 | |
|
| |||||
| White | 82 | 85 | 90 | 87 | |
|
| |||||
| Employment (%) 2 | 0.68 | ||||
|
| |||||
| Full-time | 48 | 46 | 47 | 46 | |
|
| |||||
| Part-time | 10 | 11 | 7 | 8 | |
|
| |||||
| Retired | 36 | 31 | 33 | 34 | |
|
| |||||
| Homemaker | 0 | 4 | 8 | 4 | |
|
| |||||
| Not Working | 6 | 8 | 5 | 8 | |
|
| |||||
| Marital Status (%)2 | 0.43 | ||||
|
| |||||
| Other | 2 | 10 | 5 | 4 | |
|
| |||||
| Divorced | 15 | 12 | 22 | 13 | |
|
| |||||
| Married | 61 | 65 | 62 | 66 | |
|
| |||||
| Single | 7 | 6 | 5 | 6 | |
|
| |||||
| Widowed | 15 | 7 | 7 | 9 | |
|
| |||||
| Patient Expectations | 3.8 (4.1) | 3.7 (4.2) | 3.8 (4.5) | 3.5 (4.0) | 0.30 |
| Mean with lower and upper quartiles Mean with lower and upper quartiles2 | 5.0 | 4.8 | 5.0 | 4.7 | |
|
| |||||
| Dominant Side (% Yes)2 | 74 | 59 | 67 | 72 | 0.12 |
Kruskal-Wallis Test;
Pearson Test.
A(B)C – A=lower quartile, B= median. C=upper quartile. The only statistically significant finding was a slightly older age in patients with symptoms less than 3 months.
The severity of the rotator cuff tear, as measured by MRI showed no correlation with the duration of symptoms (Table 2). Patient reported level of pain did not correlate with the durations of symptoms (Table 3). Physical examination tests for strength (Table 3) and range of motion (Table 4) had no correlation to the patient’s duration of symptoms, except forward elevation, which was ten degrees greater in patients with more than 7 months of symptoms. The duration of symptoms was not correlated with validated measures of shoulder status or general health status (Table 5).
Table 2.
Duration of Symptoms Related to Radiographic Imaging.
| Duration of Symptoms (Months) | ≤3 | 4–6 | 7–12 | >12 | p-value |
|---|---|---|---|---|---|
| Rotator Cuff Tendon Retraction (%)2 | 0.63 | ||||
| Minimal | 53 | 51 | 53 | 44 | |
| Mid-humeral | 28 | 34 | 28 | 37 | |
| Glenohumeral | 13 | 12 | 17 | 13 | |
| Glenoid | 5 | 2 | 2 | 6 | |
| Superior Humeral Head Migration (% present)2 | 14 | 14 | 15 | 16 | 0.96 |
| Number of Tendons Torn (%)2 | 0.63 | ||||
| One | 77 | 78 | 70 | 72 | |
| Two or More | 23 | 22 | 30 | 28 | |
| Supraspinatus Atrophy (%)2 | 0.75 | ||||
| Normal | 47 | 56 | 53 | 43 | |
| 25 Percent | 29 | 18 | 23 | 30 | |
| 50 Percent | 15 | 19 | 18 | 17 | |
| 75 Percent | 8 | 6 | 3 | 8 | |
| 100 Percent | 1 | 1 | 2 | 2 | |
| Infraspinatus Atrophy (%)2 | 0.96 | ||||
| Normal | 76 | 82 | 79 | 75 | |
| 25 Percent | 15 | 13 | 11 | 13 | |
| 50 Percent | 7 | 3 | 6 | 7 | |
| 75 Percent | 2 | 1 | 2 | 3 | |
| 100 Percent | 0 | 1 | 2 | 1 | |
| Teres Minor Atrophy (%)2 | 0.78 | ||||
| Normal | 98 | 97 | 100 | 99 | |
| 25 Percent | 1 | 1 | 0 | 1 | |
| 50 Percent | 1 | 1 | 0 | 0 | |
| Subscapularis Atrophy (%)2 | 0.66 | ||||
| Normal | 88 | 95 | 90 | 93 | |
| 25 Percent | 6 | 5 | 6 | 5 | |
| 50 Percent | 5 | 0 | 4 | 1 | |
| 75 Percent | 1 | 0 | 0 | 1 | |
| Acromial Shape2 | 0.07 | ||||
| Type I | 8 | 8 | 17 | 12 | |
| Type II | 81 | 64 | 68 | 69 | |
| Type III | 11 | 28 | 15 | 19 | |
| Acromiohumeral Interval (mm)1 | 8(10)11 | 9(10)11 | 8(10)11 | 8(10)11 | 0.36 |
Kruskal-Wallis Test;
Pearson Test.
A(B)C – A=lower quartile, B= median. C=upper quartile.
Table 3.
Durations of Symptoms Related to Pain and Strength.
| Duration of Symptoms (Months) | ≤3 | 4–6 | 7–12 | >12 | p-value |
|---|---|---|---|---|---|
| Pain2 | 3.1(4.6)6.4 | 2.4(4.4)6.4 | 2.6(4.3)6.6 | 2.6(4.3)6.4 | 0.74 |
| Supraspinatus Strength (%)2 | 0.49 | ||||
| 3 | 12 | 7 | 17 | 13 | |
| 4 | 63 | 62 | 53 | 54 | |
| 5 | 25 | 31 | 30 | 34 | |
| External Rotation Strength (%)2 | 0.10 | ||||
| 3 | 12 | 7 | 12 | 9 | |
| 4 | 32 | 43 | 23 | 44 | |
| 5 | 56 | 49 | 65 | 47 | |
| Flexion Strength (%)2 | 0.26 | ||||
| 3 | 10 | 5 | 8 | 8 | |
| 4 | 54 | 45 | 42 | 40 | |
| 5 | 36 | 50 | 50 | 52 | |
| Abduction Strength (%)2 | 0.41 | ||||
| 3 | 10 | 10 | 8 | 10 | |
| 4 | 59 | 44 | 43 | 47 | |
| 5 | 32 | 46 | 48 | 44 | |
| Internal Rotation Strength (%)2 | 0.16 | ||||
| 3 | 3 | 1 | 2 | 2 | |
| 4 | 9 | 5 | 0 | 11 | |
| 5 | 88 | 94 | 98 | 87 |
Kruskal-Wallis Test;
Pearson Test.
A(B)C – A=lower quartile, B= median. C=upper quartile. Strength was measured using MRC grades19, where 3= joint can be moved only against gravity with examiner’s resistance completely removed, 4= strength reduced, but contraction can still move joint against resistance, 5=muscle contracts against full resistance
Table 4. Durations of Symptoms Related to Range of Motion.
Kruskal-Wallis Test used.
| Duration of Symptoms (Months) | ≤3 | 4–6 | 7–12 | >12 | p-value |
|---|---|---|---|---|---|
| Elevation | 115(160)180 | 140(160)180 | 130(170)180 | 142(170)180 | 0.032 |
| Extension | 30(30)50 | 30(40)60 | 30(30)40 | 30(40)50 | 0.26 |
| Abduction | 60(80)90 | 70(80)90 | 70(80)90 | 70(80)90 | 0.22 |
| Adduction | 30(30)50 | 30(40)60 | 30(40)60 | 30(30)60 | 0.095 |
| External Rotation in Adduction | 40(60)60 | 40(60)60 | 42(60)60 | 40(60)60 | 0.24 |
| Internal Rotation in Adduction | 60(60)60 | 60(60)60 | 60(60)60 | 60(60)60 | 0.13 |
| External Rotation in Abduction | 60(80)90 | 70(80)90 | 70(80)90 | 70(90)90 | 0.76 |
| Internal Rotation in Abduction | 20(50)60 | 20(40)68 | 30(50)60 | 30(30)60 | 0.79 |
A(B)C – A=lower quartile, B= median. C=upper quartile. Rotations were measured with arm at side (adduction) or at 90 degrees of abduction (abduction). The only statistically significant finding was found to affect those who had symptoms for 7 months or more, who had 10 degrees more forward elevation.
Table 5.
Duration of Symptoms Related to Patient Reported Outcome Scores.
| Duration of Symptoms (Months) | ≤3 | 4–6 | 7–12 | >12 | p-value |
|---|---|---|---|---|---|
| Shoulder Activity Score1 | 5(9)13 | 8(11)14 | 8(11)13 | 7(10)13 | 0.73 |
| ASES Score1 | 39(55)65 | 41(54)74 | 43(52)68 | 41(57)71 | 0.62 |
| SANE Score1 | 30(50)60 | 30(50)65 | 25(40)60 | 30(50)65 | 0.43 |
| WORC Index2 | 34(46)62 | 33(44)62 | 34(46)58 | 32(45)62 | 0.95 |
| SF-12V2 Mental Component2 | 37(41)44 | 37(40)44 | 39(42)44 | 36(42)44 | 0.31 |
| SF-12V2 Physical Component2 | 34(35)36 | 35(36)36 | 35(36)36 | 34(35)36 | 0.95 |
Kruskal-Wallis Test;
Pearson Test.
A(B)C – A=lower quartile, B= median. C=upper quartile.
Discussion
The results from this large cross-sectional study are surprising. If we assume that the rotator cuff tear is the source of the patient’s symptoms, then it follows that longer duration of symptoms should correlate with larger rotator cuff tear size, more muscle atrophy, and poorer active motion and more weakness among physical examination findings. Our results reveal that none of these measures of rotator cuff tear severity appear to be related to a patient’s duration of symptoms. We found no correlation with other features including the patient’s reported severity of pain and status of the patient’s shoulder as measured by validated outcome scores.
Interestingly, there are multiple lines of evidence that suggest that pain as a symptom may not be clearly associated with rotator cuff disease. Many patients will report significant pain relief with non-operative treatment of rotator cuff tears1, 18, 20. The severity of a patient’s pain does not correlate with the severity of rotator cuff disease8, and patients in whom a rotator cuff repair fails will have outcome score improvement identical to patients in whom the repair heals28. This evidence compels an examination of the assumption that rotator cuff tears are the source of a patient’s symptoms, and suggests that pain in this patient population may be originating from other sources.
Some authors have recommended using duration of symptoms as a guide to recommend surgical repair of rotator cuff tears2, 6, 10, 21, 23, 34. The goals of rotator cuff repair are to reduce pain and improve function, however the indications for operative treatment of a full thickness rotator cuff tear are not clearly defined21, 34, which may explain why there is little agreement in the approach to patients9, and the existence of geographic variation in rotator cuff repair rates31. The results of this study would suggest that the duration of symptoms might not be the best historical feature to use when deciding a treatment approach for patients with atraumatic full thickness rotator cuff tears.
The strengths of this study include the large population from across the United States in both academic and private practice environments-features that allow generalization of the results, and the use of assessments that have been found to be reliable and valid. Limitations include the fact that this study population did not include patients with a history of injury and the findings would not apply to patient with traumatic rotator cuff tears. In fact, with regard to acute traumatic rotator cuff tears, the duration of symptoms has been related to muscular atrophy, tendon retraction, tear size and operative outcomes2, 10–12, 14, 30, 34. In addition, in this population without a history of injury, collecting data on the duration of a patient’s symptoms may introduce the potential for recall bias. Without an exact date of injury, patients may over- or under-represent the duration of their symptoms. Patients may have reported the duration of symptoms incorrectly or may have been unable to recall an injury. Furthermore, while time is a continuous variable, the duration of symptoms in the questionnaire was treated as a categorical variable to assist with comparisons between groups of patients, which will reduce the statistical power of this variable.
Conclusions
Despite these limitations, this cross sectional study of a large population of patients with symptomatic atraumatic full thickness rotator cuff tears failed to demonstrate a correlation between the duration of symptoms and the anatomic severity of rotator cuff disease, physical examination findings, or validated patient reported measures of shoulder status. There appears to be only a weak relationship between the duration of symptoms and features associated with rotator cuff tears.
Acknowledgments
This work was supported by the following Funding Agencies
Arthrex Corporation-Unrestricted Research Gift
NFL Charities-Medical Research Grant
NIH-Grant Number-5K23- AR05392-05from the National Institute of Arthritis and Musculoskeletal and Skin Diseases
AOSSM Career Development Award
The authors would like to acknowledge the following research personnel from their respective institutions: Vanderbilt University: Brooke Rode; BA; Washington University in St. Louis: Linda Burnworth, Amanda Haas MA, Deb Hanson; University of Iowa: Carla Britton PhD; Hospital for Special Surgery: Samuel Chu, Jessica Ryu, Patrick Grimm, Kaitlyn Lillemoe, and Brian Boyle. The Ohio State University: Angela Pedroza BS; University of California-San Francisco: May Shishido; Orthopaedic Institute: Kari Caspers; Knoxville Orthopaedic Clinic: Lori Sharp PA-C, and Jeff Jarnigan PA-C.
Footnotes
IRB approval was obtained at Vanderbilt University (#060109), University of Colorado (#06-0421), University of Iowa (#200605752), The Ohio State University (#200605752), Washington University in St. Louis (#06-0634), Hospital for Special Surgery (#27008), University of California, San Francisco (#H48075-29336-05), Orthopaedic Institute (Avery IRB #2006.049), and Knoxville Orthopaedic Institute (Brany IRB #07-08-88-122).
The following authors report no potential conflicts of interest: Kenneth P Unruh, MD, John E. Kuhn, MD, MS, Rosemary Sanders, BA, Qi An, MS, Keith M. Baumgarten, MD, Julie Y. Bishop, MD, Robert H. Brophy, MD, James L. Carey, MD MPH, Brian G. Holloway, MD, Grant L. Jones, MD, Benjamin C. Ma, MD, Robert G. Marx, MD MPH, Eric C. McCarty, MD, Souray K. Poddar, MD, Matthew V. Smith, MD, Edwin E. Spencer, MD, Armando F. Vidal, MD, Brian R. Wolf, MD, Warren R. Dunn, MD MPH.
Rick W. Wright, MD reports the following conflicts of interest: Consultant with Flexion Therapeutics and ISTO Technologies Inc.; Research Grants from Smith and Nephew and NIH; National Institute of Arthritis & Musculoskeletal & Skin Diseases; and Book royalties from Kluwer Lippincott Williams & Wilkins, however none of these are related to the work in this manuscript.
Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
References
- 1.Ainsworth R, Lewis JS. Exercise therapy for the conservative management of full thickness tears of the rotator cuff: a systematic review. Br J Sports Med. 2007 Apr;41(4):200–10. doi: 10.1136/bjsm.2006.032524. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Bassett RW, Cofield RH. Acute tears of the rotator cuff. The timing of surgical repair. Clin Orthop Relat Res. 1983 May;(175):18–24. [PubMed] [Google Scholar]
- 3.Baumgarten KM, Carey JL, Abboud JA, Jones GL, Kuhn JE, Wolf BR, et al. Reliability of determining and measuring acromial enthesophytes. Hss J. 2011 Oct;7(3):218–22. doi: 10.1007/s11420-011-9209-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Baumgarten KM, Vidal AF, Wright RW. Rotator Cuff Repair Rehabilitation: A Level I and II Systematic Review. Sports Health. 2009 Mar;1(2):125–30. doi: 10.1177/1941738108331200. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Bjorkenheim JM, Paavolainen P, Ahovuo J, Slatis P. Surgical repair of the rotator cuff and surrounding tissues. Factors influencing the results. Clin Orthop Relat Res. 1988 Nov;(236):148–53. [PubMed] [Google Scholar]
- 6.Bokor DJ, Hawkins RJ, Huckell GH, Angelo RL, Schickendantz MS. Results of nonoperative management of full-thickness tears of the rotator cuff. Clin Orthop Relat Res. 1993 Sep;(294):103–10. doi: 10.1097/00003086-199309000-00013. [DOI] [PubMed] [Google Scholar]
- 7.Brophy RH, Beauvais RL, Jones EC, Cordasco FA, Marx RG. Measurement of shoulder activity level. Clin Orthop Relat Res. 2005 Oct;439:101–8. doi: 10.1097/01.blo.0000173255.85016.1f. [DOI] [PubMed] [Google Scholar]
- 8.Dunn WR, Khazzam MS, Baumgarten KM, Bishop JY, Brophy RH, et al. Symptoms of Pain Do Not Correlate with Rotator Cuff Tear Severity. American Academy of Orthopaedic Surgeons Annual Meeting; San Diego, CA. February 16, 2011. [Google Scholar]
- 9.Dunn WR, Schackman BR, Walsh C, Lyman S, Jones EC, Warren RF, et al. Variation in orthopaedic surgeons’ perceptions about the indications for rotator cuff surgery. J Bone Joint Surg Am. 2005 Sep;87(9):1978–84. doi: 10.2106/JBJS.D.02944. [DOI] [PubMed] [Google Scholar]
- 10.Feng S, Guo S, Nobuhara K, Hashimoto J, Mimori K. Prognostic indicators for outcome following rotator cuff tear repair. J Orthop Surg (Hong Kong) 2003 Dec;11(2):110–6. doi: 10.1177/230949900301100202. [DOI] [PubMed] [Google Scholar]
- 11.Gerber C, Fuchs B, Hodler J. The results of repair of massive tears of the rotator cuff. J Bone Joint Surg Am. 2000 Apr;82(4):505–15. doi: 10.2106/00004623-200004000-00006. [DOI] [PubMed] [Google Scholar]
- 12.Goutallier D, Postel JM, Bernageau J, Lavau L, Voisin MC. Fatty muscle degeneration in cuff ruptures. Pre- and postoperative evaluation by CT scan. Clin Orthop Relat Res. 1994 Jul;(304):78–83. doi: 10.1097/00003086-199407000-00014. [DOI] [PubMed] [Google Scholar]
- 13.Henn RF, Kang L, Tashjian RZ, Green A. Patients’ preoperative expectations predict the outcome of rotator cuff repair. J Bone Joint Surg Am. 2007 Sep;89(9):1913–9. doi: 10.2106/JBJS.F.00358. [DOI] [PubMed] [Google Scholar]
- 14.Iannotti JP. Full-thickness rotator cuff tears: factors affecting surgical outcome. J Am Acad Orthop Surg. 1994 Mar;2(2):87–95. doi: 10.5435/00124635-199403000-00002. [DOI] [PubMed] [Google Scholar]
- 15.Kirkley A, Alvarez C, Griffin S. The development and evaluation of a disease-specific quality-of-life questionnaire for disorders of the rotator cuff: The Western Ontario Rotator Cuff Index. Clin J Sport Med. 2003 Mar;13(2):84–92. doi: 10.1097/00042752-200303000-00004. [DOI] [PubMed] [Google Scholar]
- 16.Koester MC, Dunn WR, Kuhn JE, Spindler KP. The efficacy of subacromial corticosteroid injection in the treatment of rotator cuff disease: A systematic review. The J Am Acad Orthop Surg. 2007 Jan;15(1):3–11. doi: 10.5435/00124635-200701000-00002. [DOI] [PubMed] [Google Scholar]
- 17.Kuhn JE. Exercise in the treatment of rotator cuff impingement: a systematic review and a synthesized evidence-based rehabilitation protocol. J Shoulder Elbow Surg. 2009 Jan-Feb;18(1):138–60. doi: 10.1016/j.jse.2008.06.004. [DOI] [PubMed] [Google Scholar]
- 18.Kuhn JE, DW, Sanders R, An Q, Baumgarten KM, Bishop JY, Brophy RH, Carey JL, Holloway BG, Jones GL, Ma CB, Marx RG, McCarty EC, Poddar SK, Smith MV, Spencer EE, Vidal AF, Wolf BR, Wright RW. Effectiveness of Physical Therapy in Treating Atraumatic Asymptomatic Full Thickness Rotator Cuff Tears. A Multicenter Prospective Cohort Study. J Shoulder Elbow Surg. 2013 Oct;22(10):1371–9. doi: 10.1016/j.jse.2013.01.026. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Medical Research Council. Aids to the examination of the peripheral nervous system, Memorandum no. 45. Her Majesty’s Stationery Office; London: 1981. [Google Scholar]
- 20.Moosmayer S, Lund G, Seljom U, Svege I, Hennig T, Tariq R, et al. Comparison between surgery and physiotherapy in the treatment of small and medium-sized tears of the rotator cuff: A randomised controlled study of 103 patients with one-year follow-up. J Bone Joint Surg Br. 2010 Jan;92(1):83–91. doi: 10.1302/0301-620X.92B1.22609. [DOI] [PubMed] [Google Scholar]
- 21.Oh LS, Wolf BR, Hall MP, Levy BA, Marx RG. Indications for rotator cuff repair: a systematic review. Clin Orthop Relat Res. 2007 Feb;455:52–63. doi: 10.1097/BLO.0b013e31802fc175. [DOI] [PubMed] [Google Scholar]
- 22.Patte D. Classification of rotator cuff lesions. Clin Orthop Relat Res. 1990 May;(254):81–6. doi: 10.1097/00003086-199005000-00012. [DOI] [PubMed] [Google Scholar]
- 23.Petersen SA, Murphy TP. The timing of rotator cuff repair for the restoration of function. J Shoulder Elbow Surg. 2011 Jan;20(1):62–8. doi: 10.1016/j.jse.2010.04.045. [DOI] [PubMed] [Google Scholar]
- 24.Reilly P, Macleod I, Macfarlane R, Windley J, Emery RJH. Dead men and radiologists don’t lie: a review of cadaveric and radiological studies of rotator cuff tear prevalence. Ann R Coll Surg Engl. 2006;88(2):116–121. doi: 10.1308/003588406X94968. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Richards RR, An KN, Bigliani LU, Friedman RJ, Gartsman GM, Gristina AG, et al. A standardized method for the assessment of shoulder function. J Shoulder Elbow Surg. 1994 Nov;3(6):347–52. doi: 10.1016/S1058-2746(09)80019-0. [DOI] [PubMed] [Google Scholar]
- 26.Romeo AA, Hang DW, Bach BR, Jr, Shott S. Repair of full thickness rotator cuff tears. Gender, age, and other factors affecting outcome. Clin Orthop Relat Res. 1999 Oct;(367):243–55. doi: 10.1097/00003086-199910000-00031. [DOI] [PubMed] [Google Scholar]
- 27.Sangha O, Stucki G, Liang MH, Fossel AH, Katz JN. The Self-Administered Comorbidity Questionnaire: a new method to assess comorbidity for clinical and health services research. Arthritis Rheum. 2003 Apr;49(2):156–63. doi: 10.1002/art.10993. [DOI] [PubMed] [Google Scholar]
- 28.Slabaugh MA, Nho SJ, Grumet RC, Wilson JB, Seroyer ST, Frank RM, et al. Does the literature confirm superior clinical results in radiographically healed rotator cuffs after rotator cuff repair? Arthroscopy. 2010 Mar;26(3):393–403. doi: 10.1016/j.arthro.2009.07.023. [DOI] [PubMed] [Google Scholar]
- 29.Spencer EE, Jr, Dunn WR, Wright RW, Wolf BR, Spindler KP, McCarty E, et al. Interobserver agreement in the classification of rotator cuff tears using magnetic resonance imaging. Am J Sports Med. 2008 Jan;36(1):99–103. doi: 10.1177/0363546507307504. [DOI] [PubMed] [Google Scholar]
- 30.Thomazeau H, Boukobza E, Morcet N, Chaperon J, Langlais F. Prediction of rotator cuff repair results by magnetic resonance imaging. Clin Orthop Relat Res. 1997 Nov;(344):275–83. doi: 10.1097/00003086-199711000-00027. [DOI] [PubMed] [Google Scholar]
- 31.Vitale MG, Krant JJ, Gelijns AC, Heitjan DF, Arons RR, Bigliani LU, et al. Geographic variations in the rates of operative procedures involving the shoulder, including total shoulder replacement, humeral head replacement, and rotator cuff repair. J Bone Joint Surg Am. 1999 Jun;81(6):763–72. doi: 10.2106/00004623-199906000-00003. [DOI] [PubMed] [Google Scholar]
- 32.Ware J, Kosinski M, Keller SD. A 12-Item Short-Form Health Survey: construction of scales and preliminary tests of reliability and validity. Med Care. 1996 Mar;34(3):220–33. doi: 10.1097/00005650-199603000-00003. [DOI] [PubMed] [Google Scholar]
- 33.Williams GN, Gangel TJ, Arciero RA, Uhorchak JM, Taylor DC. Comparison of the Single Assessment Numeric Evaluation method and two shoulder rating scales. Outcomes measures after shoulder surgery. Am J Sports Med. 1999 Mar-Apr;27(2):214–21. doi: 10.1177/03635465990270021701. [DOI] [PubMed] [Google Scholar]
- 34.Wolf BR, Dunn WR, Wright RW. Indications for repair of full-thickness rotator cuff tears. Am J Sports Med. 2007 Jun;35(6):1007–16. doi: 10.1177/0363546506295079. [DOI] [PubMed] [Google Scholar]
- 35.Yamaguchi K, Sher JS, Andersen WK, Garretson R, Uribe JW, Hechtman K, et al. Glenohumeral motion in patients with rotator cuff tears: a comparison of asymptomatic and symptomatic shoulders. J Shoulder Elbow Surg. 2000 Jan-Feb;9(1):6–11. doi: 10.1016/S1058-2746(00)90002-8. [DOI] [PubMed] [Google Scholar]
- 36.Yamaguchi K, Tetro AM, Blam O, Evanoff BA, Teefey SA, Middleton WD. Natural history of asymptomatic rotator cuff tears: a longitudinal analysis of asymptomatic tears detected sonographically. J Shoulder Elbow Surg. 2001 May-Jun;10(3):199–203. doi: 10.1067/mse.2001.113086. [DOI] [PubMed] [Google Scholar]