|Year : 2007 | Volume
| Issue : 3 | Page : 82-86
Risk factors for the development of rotator cuff disease
JR Northover, P Lunn, DI Clark, M Phillipson
Department of Trauma and Orthopaedics, Derbyshire Royal Infirmary, London Road, Derby, Derbyshire DE1 2QY, United Kingdom
J R Northover
Department of Trauma and Orthopedics, Derbyshire Royal Infirmary, London Road, Derby, Derbyshire DE1 2QY
Source of Support: None, Conflict of Interest: None
| Abstract|| |
We have undertaken a case control study of 300 patients to ascertain some of the etiological variables in the development of rotator cuff disease.
Materials and Methods: The results of 300 questionnaires of two groups of 150 people were compared. The first group with symptoms of impingement and ultrasound appearances of rotator cuff pathology (mean age 59.0, range 24-86) were compared to a second group of asymptomatic controls (mean age 60.6, range 35-90).
Results: Activities that increase the risk of developing rotator cuff pathology include occupations that involve manual (odds ratio 3.81) and/or overhead work (3.83), weight training (2.32) and swimming (1.98). Patient factors that increase the risk include diabetes (3.34) and general osteoarthritis (2.39).
Keywords: Impingement, risk factors, rotator cuff disease
|How to cite this article:|
Northover J R, Lunn P, Clark D I, Phillipson M. Risk factors for the development of rotator cuff disease. Int J Shoulder Surg 2007;1:82-6
| Introduction|| |
Rotator cuff disease is a common problem, affecting between 15%  and 23%  of the population. It also has a significant impact on patient well-being and the economy accounting for 18% of disability payments for musculo-skeletal disorders.  Rotator cuff pathology is a spectrum of disease ranging from inflammation to full thickness tears. There is still debate on the exact mechanisms by which the pathological process of the disease occurs. This is mostly divided between the Intrinsic and Extrinsic theories.
The etiology of the disease is also complex and multi-factorial. Previous studies have shown links between rotator cuff pathology and strenuous shoulder intensive work,  increasing age, , overhead/throwing sports  and genetic factors.  Work by Jarvholm et al .  on muscle physiology has also shown that raising the arm above 30 0 increases the pressure within the supraspinatus muscle to an extent that might impair normal muscle blood flow. This would imply that regular or prolonged overhead activities are also a risk factor.
A number of work activities and occupations have been implemented as causative factors in the development of rotator cuff disease such as: repetitive work, vibration (working with pneumatic tools), and lifting/ carrying heavy loads. To date there has been little research into the roll of occupation in the development of rotator cuff disease.
| Materials and Methods|| |
Following ethical approval, a "cases" group of 150 patients were recruited from the shoulder clinics at the Derbyshire Royal Infirmary between January 2005 and August 2005 and invited to take part in the study. All patients in this group were examined by a consultant orthopedic surgeon with an interest in shoulder surgery. All patients were diagnosed as having primary rotator cuff impingement based on history, physical examination with positive Neer's and Hawkins' provocative impingement signs with relief of symptoms with a subacromial injection of 10mls 1% Lignocaine (Neer's test) and in the absence of osteoarthritis on radiographic examination. Patients in whom the diagnosis of primary impingement was uncertain or due to secondary causes were not considered for inclusion into the study. All patients also had evidence of rotator cuff pathology on ultrasound scanning (evidence of inflammation with fluid seen within the tendon sheath and/or partial or full thickness cuff tears). Ultrasound scanning was performed by a single senior radiologist with an interest in musculo-skeletal imaging. Informed consent was sought from these patients to participate in the study and they were asked to complete a questionnaire. Questions covered basic demographics, work history, hobbies, and medical history (Appendix 1). Their shoulders were then clinically examined by the senior author and the results recorded (Appendix 2).
Our "control" group was recruited from 150 patients from asymptomatic spouses/partners also attending the clinic. This gave us a control group that were not genetically matched and of similar age. Informed consent was also sought from these patients to participate in the study and they were also asked to complete a questionnaire (Appendix 3).
Patients or controls who were unable to complete the questionnaire or unwilling to take part in the study were excluded. Patients pursuing medico-legal claims were also excluded as it was felt that they might skew the results. This numbered six in total: three were unwilling to take part in the study, one was unable to take part in the study due to a language barrier and two were perusing medico-legal claims.
As not all patients attended the clinic with an asymptomatic spouse/partner and so the shortfall in control patients was made up from patients attending the fracture clinic with non-shoulder related injury.
All results were then entered onto Microsoft Excel database for analysis. The data was then analyzed by logistic regression.
| Results|| |
The demographics of both impingement cases and control groups were compared. We found that they were of similar ages: cases mean age 59.0 years (range 24-86), controls Mean age 60.6 (range 35-90). The sex distribution in the cases population was equal with 75 males and females. In the controls population there were slightly more females than males with a distribution of 90 to 60.
The results can be seen on [Table - 1],[Table - 2]. Patient activities that increased their risk of developing rotator cuff disease include overhead work, manual work, hammering, weight training and swimming. The use of vibrating tools appears to increase the risk of rotator cuff disease with an odds ratio of 1.95 but this was not statistically significant ( P value of 0.06). Gardening, racquet sports and throwing sports appear to pose no significant risk.
Patient medical factors contributing to the risk of developing rotator cuff disease include diabetes and osteoarthritis. We were unable to demonstrate any significant risk from smoking, osteoporosis, or previous shoulder fracture or dislocation. The presence of rheumatoid arthritis initially appeared to protect against rotator cuff disease with an odds ratio of 0.51 but again this was not statistically significant ( P =0.172).
| Discussion|| |
The age and sex distribution of our cases patient group correlates with Milgrom et al.  findings as well as our failure to demonstrate any significance effect of hand dominance.
People who undertake manual work are at higher risk of developing rotator cuff disease compared to those who have a clerical job. There also appears to be a relationship between the increasing strenuousness of the work undertaken and the risk of developing rotator cuff disease, with clerical, light and heavy manual work having odds ratios of 1.00, 1.85 and 3.81 respectively. Regular overhead activities also increase the risk of rotator cuff disease with an odds ratio of 3.83. These results seem to correlate well with the findings of Frost and Anderson  in manual and clerical abattoir workers and confirm clinically the muscle physiology work of Jarvholm et al .  These observations are strengthened further by the increase risk in patients undertaking shoulder intensive recreational activities such as swimming and weight training (odds ratios of 1.98 and 2.32 respectively). The increased risk associated with hammering and the use of vibrating tools may be because these activities are generally associated with heavy manual and/or overhead work, which also have an increased odds ratio, rather than the effects of these activities in isolation.
We have tried to reduce inter-observer error in this study by having all of the ultrasounds performed by one, senior radiologist with an interest in musculo-skeletal imaging and having all of the patients interviewed and examined by one clinician.
Some of the questions in the questionnaire may have been open to interpretation by the patients, for example patient interpretation of work intensity. In this situation examples were given to help guide patients answers. We also tried to quantify the amount of overhead work undertaken by asking how much and how often it was performed.
We found it interesting that patients with rheumatoid arthritis seemed to have a reduced risk of rotator cuff disease (although this was not statically significant) particularly in view of Antoniou et al.  work on crystal arthropathies. Although rheumatoid arthritis and crystal arthropathies are not directly comparable, Antoniou did conclude that inflammatory mediators "….only can be detrimental to the structures in the glenohumoral joint." It may be that the incidence of rotator cuff pathology is indeed higher in patients with rheumatoid arthritis but they may mistake the pain that they feel from shoulder impingement for inflammatory pain of the glenohumoral joint and so do not feel it appropriate to seek advice from an orthopaedic surgeon. Patients who suffer from osteoarthritis seem to have an increased risk of rotator cuff disease. This may predispose them to the formation of sub-acromial osteophytes at the acromio-clavicular joint, which may be abrasive to the supraspinatus tendon causing inflammation and tears.
Also interesting was the findings that diabetes was associated with a significant risk to the development of the rotator cuff disease but smoking does not. It could be assumed that diabetes affects the microvascular blood supply to the tendon impeding the supply of nutrients and thereby predisposing it to atrophy and reducing its ability to repair itself in the event of trauma. If this was indeed the case you would expect smoking to also increase the risk of rotator cuff disease by a similar mechanism. However, this study found that smoking does not increase the risk of developing rotator cuff disease, having an odds ratio of only 0.89. We must therefore question the disease pathway originally postulated.
Unfortunately this study did not have the funding or resources to perform ultrasound scans on the control population and so we are unable to comment on the ultrasound appearance of their rotator cuff. The results of this study therefore pertain to symptomatic rotator cuff disease only.
Some of the variables looked at in this study showed inconclusive or results that were not statistically significant (shoulder dislocation, fracture, etc.) due to low numbers of patients within these groups. It would be interesting to know if these were risk factors for rotator cuff disease and we recommend more research be done in this area to answer these questions.
| Conclusions|| |
People who undertake occupations that involve manual and overhead work are at risk of developing symptomatic rotator cuff disease. This would also seem to be the case in people who undertake shoulder intensive recreational activities such as swimming and weight training. Patient factors that increase the risk include diabetes and osteoarthritis.
| References|| |
|1.||Sher JS, Uribe JW, Posanda A, Murphy BJ, Zlatkin MB. Abnormal findings on magnetic resonance imaging of asymptomatic shoulders. J Bone Joint Surg Am 1995;77:10-5. |
|2.||Tempelhof S, Rupp S, Seil R. Age related prevalence of rotator cuff tears in asymptomatic shoulders. J Shoulder Elbow Surg 1999;8:296-9. [PUBMED] |
|3.||Nygren A, Berglund A, von Koch M. Neck-and-shoulder pain, an increasing problem. Strategies for using insurance material to follow trends. Scand J Rehabil Med Suppl 1995;32:107-12. |
|4.||Frost P, Anderson JH. Shoulder impingement syndrome in relation to shoulder intensive work. Occup Environ Med 1999;56:494-8. |
|5.||DePalma AF. Surgery of the shoulder. JB Lipincott: Philadelphia; 1973. |
|6.||Ozaki J, Fujimoto S, Nakagawa Y, Masuhara K, Tamai S. Tears of the rotator cuff associated with pathological changes of the acromion. J Bone Joint Surg Am 1988;70:1224-30. [PUBMED] |
|7.||Gerber C, Sebesta A. Impingement of the deep surface of the subscapularis tendon and the reflection pulley on the anterosuperior glenoid rim: A preliminary report. J Shoulder Elbow Surg 2000;9:483-90. [PUBMED] [FULLTEXT] |
|8.||Harvie P, Ostlere SJ, Teh J, McNally EG, Clipsham K, Burston BJ, et al . Genetic influences in the aetiology of tears of the rotator cuff. Sibling risk of a full thickness tear. J Bone Joint Surg Br 2004;86:696-700. |
|9.||Jarvholm U, Palmerual G, Herberts P, H φgfors C, Kadefors R. Intramuscular pressure and electromyography in the superspinatous muscle at shoulder abduction. Clin Orthop Relat Res 1989;245:102-9. |
|10.||Milgram C, Schaffler M, Gilbert S, van Holsbeeck M. Rotator cuff changes in asymptomatic adults: The effect of age, hand dominance and gender. J Bone Joint Surg Br 1995;77:296-8. |
|11.||Antoniou J, Tsai A, Baker D, Schumacher R, Williams GR, Iannotti JP. Milwaukee shoulder: Correlating possible etiological variables. Clin Orthop Relat Res 2003;407:79-85. [PUBMED] [FULLTEXT] |
[Table - 1], [Table - 2]