Relationship between chronic pathologies of the supraspinatus tendon and the long head of the biceps tendon: systematic review

Inclusion criteria of the selected articles were as follows:

The only exclusion criterion in the study is as follows:

→ Case studies.

The search for articles in databases was not restricted to the year of publication.

An electronic search was performed for the months of May to July 2013 in the following databases: CINAHL, MEDLINE, Scopus, PEDro, WOK, IME (CSIC), Dialnet. Search terms and Boolean operators used are shown in Table 3.

The initial search in electronic databases provided a total of 1043 items. Out of all the articles selected, 677 were repeated, so that 366 manuscripts remained to be analyzed. Next, those whose titles were unrelated to the topic were eliminated, leaving 81 works. A review of the summary in these articles was carried out, leaving 24 texts. Finally, 19 articles were ruled out after the full text review did not meet the inclusion criteria. The 5 studies finally included in the review were: Singajaru VM et al.[20], Murthi AM et al.[16], Modi CS et al.[23], Chelli BM et al.[21] and Braun S et al.[22]. The outline of the search strategy is shown in Figure 1.

The age of the subjects included in the review was between 35 and 80 years, ages at which most chronic rotator cuff injuries occur[7, 8, 10].

Regarding sexes, in the study of Chelli BM et al.[23] there were 35 males and 29 females, and in the Braun S et al.[22] study more men were observed (n=155) than women (n=74). In Singajaru VM et al.[20], Murthi AM et al.[16] and Modi CS et al.[23] studies, this information is not specified.

The sample size varies considerably depending on the type of study, those of Murthi AM et al.[16] (n = 200), Modi CS et al.[23] (n = 100) and Braun S et al.[22] (n = 207) were very high; while it was lower in Chelli BM et al.[21] (n = 64) and Singajaru VM et al.[20] (n = 28).

Regarding the characteristics of the lesions that the subjects in each study present, we found that most participants had a clinical diagnosis of rotator cuff pathology. Once the muscles belonging to the rotator cuff were studied by means of invasive diagnoses (arthroscopy) and non-invasive (evaluation test, radiography, ultrasonography and magnetic resonance), we observed that the high percentage of involvement of the supraspinatus tendon and LHBT existed in the majority. In studies with fewer participants such as the one of Singajaru VM et al.[20], an association of both pathologies was observed in 78.5% of the subjects studied. However, the authors who evaluated a larger sample such as Braun S et al.[22] and Modi CS et al.[23] a lower percentage of lesions associated to both tendons (67.2% and 22%) was seen.

All subjects from the articles analyzed were suffering from a chronic RC pathology, or LHBT lesion; both of which had been previously diagnosed by a physician[16, 20‐23]. The 5 studies mention the diagnosis method. The most common are:

Among the diagnosis methods used in assessing the shoulder, we found imaging diagnosis, especially by ultrasonography, corresponded to the gold standard[18].

Regarding the variables analyzed in the selected 5 studies, all the authors focused on the description of morphological and histological changes of the tendons involved through imaging or arthroscopy, mainly concentrating their studies on the existence of tears, tendinopathies or inflammatory processes[16, 21‐23]. Singajaru VM et al.[20], besides examining the above, also studied pain and the functional limitation.

Murthi AM et al.[16], included an impingement syndrome and RC tendinopathy in their sample subjects, after previously undergoing arthroscopy. These subjects were divided into two groups: tenosynovectomy and tenodesis. In group 1 (n = 120), undergoing tenosynovectomy, 34% of the subjects had a partial RC tear, while 57% had a complete one. The 49% of all patients had associated LHBT with degenerative and inflammatory signs. In group 2 (n = 80), intervened by tenodesis, there were 63% with microscopic inflammatory changes, 9% of cases with signs of inflammation and calcification and 15% with fibrosis.

Singaraju VM et al.[20] determined the histological changes produced at LHBT level in persons diagnosed for RC tendinitis in their study, focusing especially on the supraspinatus tendon. To do this, they divided the 28 subjects into two equal groups, with the objective of comparing the subjects with RC affectation to those who did not. They found histological changes produced at LHBT level in a RC tendinitis in their study. Obviously microscopic inflammation changes were found, which ensured tendon damage, such as the presence of two neuropeptides involved in pain perception, CGRP and substance P, at the level of nerve endings in the inflamed tissues. Of 14 patients with supraspinatus affectation, 11 had damaged LHBT, finding a relationship between both lesions. According to the author, the difference between both groups was statistically significant (P = 0.04).

Next, the study performed by Chelli BM et al.[21] in 2010 similarly supported an association in the prevalence of both pathologies. Out of 64 subjects included in the study, 55 showed a supraspinatus pathology and among these, 16 showed alterations in LHBT.

Similarly, Braun S et al.[22] describes the pathology associated with LHBT affecting the biceps pulley, which the supraspinatus tendon forms part of and found 67 patients with biceps lesions and 45 with associated supraspinatus damage.

Finally, Modi CS et al.[23] analyzes the changes in all the RC tendons, including LHBT in subjects with previous shoulder arthroscopy. Out of 100 patients, 62 had supraspinatus tendon pathologies, of which 22 had a LHBT associated injury. This would imply an epidemiological relationship between both lesions that were found. Table 4 summarizes the characteristics and results of the studies included in our review.