Abstract
Background and Aim
Several patient-related factors have been identified which are responsible for the development of rotator cuff tears. The purpose of the study was to assess various parameters which can be risk factors for the development of supraspinatus tendon tear.
Methods
A total of 100 patients with symptomatic rotator cuff tear, aged > 18 years, of either gender, presenting to the outpatient department were included in this cross-sectional study. Magnetic resonance imaging was done and based on its results; patients were identified for the type of tear. Demographic, clinical, and biochemical factors affecting the tears were assessed using logistic regression analysis.
Results
Factors such as age, gender, pain radiation, night pain, and analgesic intake had significant association with supraspinatus tendon tears.
Conclusion
“Pain radiation” and “Analgesic intake” were two new parameters found associated with the supraspinatus tendon tears. New parameters that have been assessed as risk factors will help in better understanding of supraspinatus tendon tears.
Keywords: Magnetic resonance imaging, Shoulder pain, Rotator cuff, Analgesics, Partial tear
Introduction
Shoulder disorders rank among the most prevalent musculoskeletal disorders. Shoulder pain can be a debilitating condition and is estimated to be the third most common cause of musculoskeletal consultation in primary care [1]. A supraspinatus tear is a tear or rupture of the tendon of the supraspinatus muscle. The supraspinatus is a part of the rotator cuff of the shoulder and is accompanied with another rotator cuff muscle tear in most cases. Trauma or repeated micro-trauma can cause such tears. It is present as a partial or full-thickness tear [2]. The incidence of partial tears in a study was found to be 28.7% and the incidence of complete rupture was found to be 30.3% [3].
There are a number of risk factors which can lead to supraspinatus tear; genetics [2, 4, 5], demographic factors such as age [4, 6], gender [4, 7], smoking [2, 4, 8], and alcohol [2]; biochemical factors such as hormonal influence [2], hypercholesterolemia [4, 9]; clinical factors including repetitive stress of lifting heavy objects [4], history of trauma [4], lack of blood supply [4, 10], ageing of rotator cuff [11], impingement lesions [12], diabetes [13, 14], and athletes have a greater risk of having a rotator cuff injury [15]. For partial tear, increased body mass density (BMI), diabetes, and practice of heavy work can be risk factors and may, eventually, lead to the development of complete/full-thickness tear [16].
It is important for surgeons to know the risk factors for tear progression, especially when non-surgical treatment is considered [17]. The knowledge of the risk factors concerning tear progression after clinical examination is important to identify the high-risk group of patients that needed further MRI diagnostic and assessment. The purpose of the study was to assess various parameters which can be risk factors for the development of supraspinatus tendon tear.
Methods
One hundred thirty-four consecutive patients with symptomatic rotator cuff tears visited our centre between June 2015 and August 2017. Of these, 100 new patients (100 shoulders) who underwent evaluation by history taking, clinical examination and magnetic resonance imaging (MRI) were enrolled. Patients aged more than 18 years, of either gender, were included. Patients with shoulder fractures, previously treated rotator cuff tears, frozen shoulder, arthritis, previous dislocation shoulder, and instability were excluded. The study was initiated after obtaining ethical approval by the Institutional ethical committee. After obtaining informed consent, all patients were evaluated by an orthopaedic surgeon. All patients underwent MRI of the shoulder, on the same day. Based on its findings, type of supraspinatus tear was identified as partial-thickness tear, complete/full-thickness tear, or no tear. The clinical examiners and MRI reporters were not the same and were blinded at each other’s findings.
Variables were selected based on AIC (Akaike information criterion)/BIC (Bayesian information criterion) values [18]. Demographic details including age, gender, occupation, and clinical features such as night pain, reduced range of motion, weakness, duration of pain, and biochemical data(serum cholesterol level) of the patients were collected using a structured questionnaire.
Statistical Analysis
Data analysis was done using R i386.3.5.1. Continuous data were represented in the form of mean ± SD and the categorical variable was represented by the frequency table. Association between categorical variables was studied using Chi-square test/Fisher’s test. Continuous data were compared using t test/Mann–Whitney U test. Trend test was done using Cochran–Armitage test. Logistic regression was used to study the factors affecting different stages of tear. p value of < 0.05 was considered statistically significant.
Results
Of the 100 subjects, 69 subjects were with supraspinatus tendinous tear which was either partial (50) or complete/full-thickness (19). Most of the subjects in the group were in the age group of 51–70 years. There was a linear trend in the proportion of tear (partial + complete) by age group (p = 0.0188). Mean age of subjects with complete/full-thickness tear and partial-thickness tear was significantly different (p = 0.0199). Out of 100 subjects, male predominance was observed. Type of occupation and trauma did not show any statistical significance in this study. Proportion of tear among male subjects was significantly (p = 0.0296) more than that of female subjects (Tables 1, 2).
Table 1.
Demographic details of the participants
| Factor | Sub-category | Total screened | With tear (partial tear + complete/full-thickness tear) | Without tear | With partial tear | With complete/full-thickness tear |
|---|---|---|---|---|---|---|
| Age group | ≤ 30 | 6 | 1 (16.67%) | 5 (83.33%) | 1 (100%) | 0 (0%) |
| 31–50 | 29 | 17 (58.62%) | 12 (41.38%) | 14 (82.35%) | 3 (17.65%) | |
| 51–70 | 57 | 44 (77.19%) | 13 (22.81%) | 32 (72.73%) | 12 (27.27%) | |
| ≥ 71 | 8 | 7 (87.5%) | 1 (12.5%) | 3 (42.86%) | 4 (57.14%) | |
| Age | Mean ± sd | 53.59 ± 12.56 | 56.20 ± 11.37 | 47.77 ± 13.29 | 54.26 ± 11.16 | 61.32 ± 10.55 |
| Gender | Male | 67 | 41 (61.19%) | 26 (38.81%) | 30 (73.17%) | 11 (26.83%) |
| Female | 33 | 28 (84.85%) | 5 (15.15%) | 20 (71.43%) | 8 (28.57%) | |
| Occupation | Govt. worker | 27 | 20 (74.07%) | 7 (25.93%) | 16 (80%) | 4 (20%) |
| Private worker | 16 | 9 (56.25%) | 7 (43.75%) | 8 (88.89%) | 1 (11.11%) | |
| Security | 2 | 0 | 2 (100%) | – | – | |
| Self employed | 12 | 7 (58.33%) | 5 (41.67%) | 4 (57.14%) | 3 (42.86%) | |
| Housewife | 34 | 27 (79.41%) | 7 (20.59%) | 18 (66.67%) | 9 (33.33%) | |
| Others | 9 | 6 (66.67%) | 3 (33.33%) | 4 (66.67%) | 2 (33.33%) | |
| Occupation | Light jobs | 78 | 56 (71.79%) | 22 (28.21%) | 42 (75%) | 14 (25%) |
| Heavy jobs | 22 | 13 (59.09%) | 9 (40.91%) | 8 (61.54%) | 5 (38.46%) |
VAS visual activity score, ROM range of motion, BMI body mass index, ADL activities of daily living
Table 2.
Clinical features of the participants
| Factor | Sub-category | Total screened | With tear (partial tear + complete/full-thickness tear) | Without tear | With partial tear | With complete/full-thickness tear |
|---|---|---|---|---|---|---|
| Dominant arm | Right | 98 | 67 (68.37%) | 31 (31.63%) | 48 (71.64%) | 19 (28.36%) |
| Left | 2 | 2 (100%) | 0 (0%) | 2 (100%) | 0 (0%) | |
| Weakness | Present | 31 | 28 (90.32%) | 3 (9.68%) | 13 (46.43%) | 15 (53.57%) |
| Absent | 69 | 41 (59.42%) | 28 (40.58%) | 37 (90.24%) | 4 (9.76%) | |
| Reduced ROM | Absent | 86 | 59 (68.6%) | 27 (31.4%) | 44 (74.58%) | 15 (25.42%) |
| Present | 14 | 10 (71.43%) | 4 (28.57%) | 6 (60%) | 4 (40%) | |
| VAS | Mean ± sd | 5.48 ± 1.31 | 5.54 ± 1.29 | 5.35 ± 1.38 | 5.42 ± 1.34 | 5.84 ± 1.12 |
| Median[range] | 5.5 [3, 9] | 5 [3, 9] | 6 [3, 9] | 5 [3, 9] | 6 [4, 8] | |
| Pain location in shoulder | Anterior | 35 | 23 (65.71%) | 12 (34.29%) | 14 (60.87%) | 9 (39.13%) |
| Lateral | 60 | 43 (71.67%) | 17 (28.33%) | 34 (79.07%) | 9 (20.93%) | |
| Posterior | 1 | 0 | 1 (100%) | – | – | |
| Others | 4 | 3 (75%) | 1 (25%) | 2 (66.67%) | 1 (33.33%) | |
| Radiation of pain | No | 35 | 19 (54.29%) | 16 (45.71%) | 14 (73.68%) | 5 (26.32%) |
| Yes | 65 | 50 (76.92%) | 15 (23.08%) | 36 (72%) | 14 (28%) | |
| Night pain | Present | 77 | 62 (80.52%) | 15 (19.48%) | 45 (72.58%) | 17 (27.42%) |
| Absent | 23 | 7 (30.43%) | 16 (69.57%) | 5 (71.43%) | 2 (28.57%) | |
| Pain in which shoulder | Right | 66 | 46 (69.7%) | 20 (30.3%) | 31 (67.39%) | 15 (32.61%) |
| Left | 34 | 23 (67.65%) | 11 (32.35%) | 19 (82.61%) | 4 (17.39%) | |
| Duration of pain | < 1 month | 7 | 4 (57.14%) | 3 (42.86%) | 2 (50%) | 2 (50%) |
| 1– < 3 months | 33 | 19 (57.58%) | 14 (42.42%) | 10 (52.63%) | 9 (47.37%) | |
| 3– < 1 year | 45 | 32 (71.11%) | 13 (28.89%) | 26 (81.25%) | 6 (18.75%) | |
| ≥ 1 year | 15 | 14 (93.33%) | 1 (6.67%) | 12 (85.71%) | 2 (14.29%) | |
| Are you taking analgesic? | Yes | 67 | 54 (80.6%) | 13 (19.4%) | 37 (68.52%) | 17 (31.48%) |
| No | 33 | 15 (45.45%) | 18 (54.55%) | 13 (86.67%) | 2 (13.33%) | |
| Is shoulder comfortable with arm at your side? | Yes | 95 | 64 (67.37%) | 31 (32.63%) | 46 (71.88%) | 18 (28.13%) |
| No | 5 | 5 (100%) | 0 (0%) | 4 (80%) | 1 (20%) | |
| Is ADL (activities of daily living) limited? | Yes | 43 | 31 (72.09%) | 12 (27.91%) | 16 (51.61%) | 15 (48.39%) |
| No | 57 | 38 (66.67%) | 19 (33.33%) | 34 (89.47%) | 4 (10.53%) | |
| Do you lifting weight to shoulder level without bending elbow? | Yes | 58 | 35 (60.34%) | 23 (39.66%) | 32 (91.43%) | 3 (8.57%) |
| No | 42 | 34 (80.95%) | 8 (19.05%) | 18 (52.94%) | 16 (47.06%) | |
| History of trauma? | No | 73 | 50 (68.49%) | 23 (31.51%) | 37 (74%) | 13 (26%) |
| Yes | 27 | 19 (70.37%) | 8 (29.63%) | 13 (68.42%) | 6 (31.58%) | |
| History of smoking? | No | 80 | 53 (66.25%) | 27 (33.75%) | 39 (73.58%) | 14 (26.42%) |
| Yes | 20 | 16 (80%) | 4 (20%) | 11 (68.75%) | 5 (31.25%) | |
| Comorbidities? | No | 52 | 33 (63.46%) | 19 (36.54%) | 25 (75.76%) | 8 (24.24%) |
| Yes | 48 | 36 (75%) | 12 (25%) | 25 (69.44%) | 11 (30.56%) | |
| BMI | Mean ± sd | 26.16 ± 3.27 | 26.33 ± 3.56 | 25.77 ± 2.50 | 26.10 ± 3.59 | 26.95 ± 3.52 |
VAS visual activity score, ROM range of motion, BMI body mass index, ADL activities of daily living
Using logistic regression, age, gender, pain radiation, night pain, analgesics intake, and weakness was observed to significantly affect the total tear (Table 3).
Table 3.
Factors affecting the overall tear
| Factors | Complete/full-thickness tear | ||
|---|---|---|---|
| Estimate | OR [95% CI] | p value | |
| Age (years) | |||
| ≥ 50 | 1.4667 | 4.3349 [1.6777–11.9818] | 0.0032* |
| < 50 | Reference | ||
| Gender | |||
| Male | − 0.9410 | 0.3903 [0.1550–0.9468] | 0. 0402* |
| Female | Reference | ||
| Radiation of pain | |||
| Yes | − 1.3699 | 0.2541 [0.0.0900–0.6550] | 0.0064* |
| No | Reference | ||
| Duration of pain (months) | |||
| < 1 month | Reference | ||
| 1–3 months | − 0.7811 | 0.4579 [0.0424,4.3079] | 0.5090 |
| 3 months–< 1 year | − 1.0364 | 0.3547 [0.0325,3.1835] | 0.3779 |
| ≥ 1 year | 1.4866 | 4.4221 [0.2510,153.9441] | 0.3434 |
| Weakness | |||
| Present | 1.1246 | 3.0846 [1.1340,8.8177] | 0.0300* |
| Absent | Reference | ||
| Night pain | |||
| Present | 2.5964 | 13.4150 [3.5601,72.2582] | 0.0005* |
| Absent | Reference | ||
| Analgesic intake | |||
| Yes | 1.7346 | 5.6667 [2.2890,15.1494] | 0.0003* |
| No | Reference | ||
Residual deviance is 149.62 AIC: 169.62
VAS visual activity score, ROM range of motion, BMI body mass index, ADL activities of daily living.
Age, gender, pain radiation, night pain, analgesics intake, and weakness significantly affected the complete/full-thickness tear. While, for partial tear gender, radiation of pain, duration of pain, and night pain affected partial tear. For elder subjects (≥ 50 years), odds of having complete/full-thickness tear was 40.65 higher than in subjects of age < 50 years. Odds of having complete/full-thickness tear was 10 and partial tear was 4.34 times higher for female subjects, as compared to male subjects. Odds of having complete/full-thickness tear was 8.67 times higher for subjects with weakness. Subjects with night pain are 3.8 times more likely to have partial tear. Odds of being complete/full-thickness tear was 4.59 times higher for subjects with analgesics intake (Table 4).
Table 4.
Factors affecting the complete/full-thickness tear and partial tear
| Factors | Complete/full-thickness tear | Partial tear | ||||
|---|---|---|---|---|---|---|
| Estimate | OR [95% CI] | p value | Estimate | OR [95% CI] | p value | |
| Age (years) | ||||||
| ≥ 50 | 3.7050 | 40.6523 [8.7214,189.4895] | < 0.0001* | 0.6070 | 1.8349 [0.6167,5.4589] | 0.2752 |
| < 50 | Reference | |||||
| Gender | ||||||
| Male | − 2.2351 | 0.1070 [0.0239,0.4787] | 0.0035* | − 1.4693 | 0.2301 [0.0591,0.8962] | 0.0342* |
| Female | Reference | |||||
| Radiation of pain | ||||||
| Yes | − 1.6136 | 0.1992 [0.064,0.6570] | 0.0081* | − 0.3659 | 0.6936 [0.2377,2.0243] | 0.0532* |
| No | Reference | |||||
| Duration of pain (months) | ||||||
| ≥ 12 | 0.5560 | 1.7437 [0.1089,27.9109] | 0.6943 | 2.5751 | 13.1330 [0.9620,179.2966] | 0.0535* |
| 3– < 12 | − 1.4801 | 0.2276 [0.0341,1.5212] | 0.1267 | 0.2444 | 1.2769 [0.2236,7.2919] | 0.7833 |
| 1–3 | − 0.6083 | 0.5443 [0.0824,3.5934] | 0.5276 | − 1.2735 | 0.2799 [0.0444,1.7648] | 0.1753 |
| < 1 | Reference | |||||
| Weakness | ||||||
| Present | 2.1595 | 8.6672 [2.5190,29.8211] | 0.0006* | 0.6164 | 1.8522 [0.5854,5.8605] | 0.2942 |
| Absent | Reference | |||||
| Night pain | ||||||
| Present | − 0.0737 | 0.9290 [2511,3.4364] | 0.9121 | 1.3374 | 3.8091 [1.0981,13.2132] | 0.0351* |
| Absent | Reference | |||||
| Analgesic intake | ||||||
| Yes | 1.5249 | 4.5946 [1.3619,15.5004] | 0.0139* | 0.8479 | 2.3347 [0.8001,6.8131] | 0.1207 |
| No | Reference | |||||
Residual deviance 263.11 Aic:303.11 Accuracy = 75.76%; No tear is taken as reference
Discussion
The knowledge of the risk factors concerning supraspinatus tendon tear progression is important to identify the high-risk group of patients that needed further MRI diagnostic and assessment, which also helps in avoiding unnecessary MRI prescriptions, and reducing the financial burden on the patients.
In the present study, demographic, clinical, and biochemical factors were evaluated. The most important findings of the present study were the factors such as age more than or equal to 50 years, male gender, radiation of pain, weakness, night pain, and analgesic intake had statistically significant relationship with the presence of supraspinatus tendon tears.
In the present study, 77% of patients aged between 51 and 70 years had symptomatic supraspinatus tendon tears and 83% of patients aged less than 30 years had no tears. For elder subjects (≥ 50 years), odds of having complete/full-thickness tear was 40.65 higher than in subjects of age < 50 years. Van Kampen et al. [19] study found similar results. Present study also reveals that partial-thickness tears were more common than full-thickness tears with the prevalence of 50% and 19%, respectively, which was also reported by Fukuda et al. [20]. Increasing incidence of asymptomatic rotator cuff tears, as high as 54%, above 60 years of age has been reported [21] suggesting rotator cuff lesions as natural correlate of aging.
In the present study, male patients were more in number than females which shows similarity with Van Kampen et al.’s [19] study. In the study conducted by Sgroi et al. [22], mean age was found to be 57.3 ± 12.0 years and females were more in number in their study which is in contrast with our study.
In the present study, types of occupation did not show any statistically significant correlation with the presence of tears. The prevalence rate of rotator cuff tears reported in other studies on French workers exposed to repetitive work was even higher, ranging between 29% in highly exposed workers and 16% in weakly exposed workers [23].
Radiation of pain in this study was seen in 77% of patients with tear, and its p value was 0.0064, suggesting highly significant association of this factor with tear. Though this feature was mentioned in various literature [15, 24], its statistical significant association with supraspinatus tear was not reported. This is the first study to report the same. Pain radiation to lateral part of arm, elbow, forearm and thumb side of the hand is explained by the C5 and C6 nerve supply of the dermatomes; C5 and C6 nerves also supply supraspinatus and infraspinatus muscles [25].
In the present study, weakness when lifting or rotating the arm was seen in 90% of patients with tear. This was statistically significant (p = 0.03). It is difficult to assess if the patient has both pain and weakness. In such cases, weakness can be assessed after giving sub-acromial anaesthetic injection as explained in Neer’ s impingement test. 41% of patients of rotator cuff tear experienced weakness in other studies [19].
In this study, we found that night pain was present in 80% of patients with tear. This was strongly statistically significant (p = 0.0005). Similar results were seen by Holtby et al. [25]. The cause for the pain at night was when patients lie on the painful side at night, they experience pain and which disturbs their sleep.
In this study, we found that the history of analgesic intake for shoulder pain was present in 80% of patients with tear. This was strongly statistically significant (p = 0.0003). Initially, the pain may be mild and only present when lifting the arm over the head, such as reaching into a cupboard. Over-the-counter medication, such as aspirin or ibuprofen, may relieve the pain initially. Over time, the pain may become more noticeable at rest, and does not reduce even with medications [26]. Its statistically significant association with supraspinatus tear was not reported. This is the first study to report the same.
In the current study, subjects with comorbid conditions were less in number which is similar to the study done by Cadogan et al. [27].
Number of studies have investigated risk factors associated with the progression of asymptomatic tears into symptomatic tears like age [28, 29], gender [28, 30], occupation [28], dominant arm, and history of trauma, combination of aging, and precarious vascularity of the supraspinatus tendon at the critical portion, repeated use of the arm above the horizontal level, injury, and subacromial impingement [24] preoperative fatty infiltration of the rotator cuff [30] which have shown significant effect on rotator cuff tear [29]
In the current study, risk factors such as genetics, hypercholesterolemia, duration of pain, trauma, smoking, co-morbidities, obesity, pain severity (VAS) did not show any statistically significant correlation as seen in other studies. Difference in the results can be due to the difference in study types and designs.
Assessing the effect of parameters like radiation of pain, night pain, weakness, analgesic intake on the tendon tears, and shoulder pain is the novelty of our study as these parameters have not been correlated with the tendon tear before. However, some limitations are small sample size and a single-centre study. Future prospective is a study with a large number of patients in multiple centres for better understanding.
Conclusion
There are various risk factors that affect the supraspinatus tendon tears. Factors like age, gender, radiation of pain, night pain, analgesics intake and weakness significantly affect supraspinatus tendon tear. Insight into these risk factors is essential to identify the “high-risk group” of patients that needed further MRI diagnostic and assessment. This knowledge of risk factors will reduce unnecessary prescription of MRI and thus are helpful in low-economy countries.
Author contributions
All the authors have contributed equally in developing the manuscript.
Compliance with ethical standards
Conflict of interest
No potential conflicts of interest relevant to this article were reported.
Ethical standard statement
Ethical approval was granted by the KLE University Ethics Committee on Human Subjects (KLEU/Ethic/2015-16/D-70). Signed written consent was obtained from all participants.
Informed consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Footnotes
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Contributor Information
Sameer Haveri, Email: drsameerhaveri@gmail.com.
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