For many years, subacromial impingement syndrome has been shown to be the reason for rotator cuff pathology. Although there are studies showing that acromial spurs and acromion types are related to rotator cuff pathology, this has not been fully proven. There are also studies that have stated that rather than the type of acromion, other factors cause the impingement in the formation of rotator cuff pathology [18–21].
Studies in literature by authors supporting the extrinsic theory have stated that routine application of acromioplasty both improves the arthroscopic visualisation and induces healing of the bleeding from the bone which occurs with the acromioplasty in the subacromial space [22, 23].
In contrast, those who support the intrinsic theory have suggested that preserving the coraco-acromial ligament in respect of glenohumeral stability both reduces costs and shortens operating time and there is no need for acromioplasty following successful rotator cuff repair [24, 25].
No consensus has been reached in literature as yet. The aim of the current study was to show whether or not there was any benefit of subacromial decompression according to acromion type in patients applied with rotator cuff repair. Evaluation was made of 150 patients with the Constant Murley score, the American Shoulder and Elbow Surgeons score and the VAS score for pain.
When evaluations were made in respect of the CM score, there was a significant difference between the preoperative and postoperative scores of all the groups (p = 0.001, p < 0.05). However, there was no difference between the postoperative scores of the three groups (p > 0.05). This demonstrated that all the groups benefitted from surgery. The application of acromioplasty or bursectomy without acromioplasty or not making any additional procedure other than rotator cuff repair was seen not to make any difference in respect of the CM score after rotator cuff repair.
There was a significant difference between the preoperative and postoperative ASES scores of all the groups (p = 0.001, p < 0.05). However, there was no difference between the postoperative ASES scores of the three groups (p > 0.05). This demonstrated that all the groups benefitted from surgery. Thus the application of acromioplasty, bursectomy, or no subacromial bursectomy procedure following rotator cuff repair was not seen to make any significant difference in respect of the ASES score. There are similar results in literature [26, 27].
However, when the VAS scores were evaluated, a significant difference was determined between the groups in respect of the postoperative VAS scores (p = 0.032, p < 0.05). The point of interest here is that there was no statistically significant difference between the group applied with acromioplasty additional to the rotator cuff repair (Group A) and the group where only bursectomy was performed after the repair (Group B) (p > 0.05). Irrespective of acromion type, acromioplasty or bursectomy applied in addition to rotator cuff repair made no difference in respect of the VAS scores. However, the postoperative VAS scores of the group not applied with any subacromial decompression procedure in addition to rotator cuff repair (Group C) were significantly higher than those of Groups A and B (p = 0.018, p = 0.029; p < 0.05). When Group C was examined, the patients with high postoperative VAS scores were seen to be those with type III acromion (p:0.021, p:0.001). No significant difference was seen between the cases with type I and type II acromion in respect of postoperative VAS scores (p > 0.05) (Table 2).
In Group A, when the VAS scores were evaluated according to acromion type, the VAS scores of cases with type I acromion were determined to be significantly higher than those of cases with type II acromion (p < 0.01).
A significant difference was determined in Group B when the postoperative VAS scores were evaluated according to acromion type (p:0.011, p < 0.05). The VAS scores of the cases with type I acromion were determined to be significantly higher than those of cases with type II acromion (p:0.009, p < 0.01). No significant difference was determined between the other acromion types in this group in respect of postoperative VAS scores (p > 0.05) (Table 3).
Finally, it was clear that acromion type showed no correlation with the VAS score. While the VAS scores of cases with type I acromion in Groups A and B were higher than those of the cases with type II, in Group C the highest VAS scores were in cases with type III acromion. Similar results have been reported in some previous studies .
Although this shows that antero-inferior acromioplasty or bursectomy applied without being aggressive after rotator cuff repair in patients with type III acromion provided a benefit in respect of the pain score, there was still seen to be no correlation between VAS score and acromion type. Previous studies have shown results that the shoulder scores of cases with type III acromion were worse than those of type I acromion .
As no consensus has been reached on this subject in literature, the cause and effect relationship has not been revealed. In the current study, type III acromion only affected the postoperative VAS score, and did not seem to affect the ASES and CM scores. Furthermore, there was no correlation of clinical significance between the postoperative acromion type and VAS score. This could be attributed to the VAS score not being a functional score, but an isolated pain score, and as it is a highly subjective scoring of pain, can vary from person to person.
However, the decrease in VAS scores from preoperative to postoperative was found to be statistically significant in all the groups (p = 0.001, p < 0.05). Thus, it can be said that all the groups benefitted from the surgery, and this benefit seems to be clearly related to the rotator cuff repair.
Very interesting results emerged from evaluating the preoperative and postoperative acromion types of the patients. In Group A where acromioplasty was applied in addition to rotator cuff repair, of the 20 cases with type I acromion preoperatively, 14 cases remained as type I postoperatively and 6 cases changed to type II. Of the 19 cases with preoperative type II acromion, 13 remained as type II postoperatively and 6 changed to type I. Of the 11 cases with preoperative type III acromion, only 1 case remained type III postoperatively, 4 changed to type I and 6 to type II (Table 4).
When performing acromioplasty in Group A, the target was to convert type II and type III acromions to type I. The target in type I acromions, because of the narrowed subacromial space, was only to remove acromial spurs. In the measurements taken after approximately 3 years, a third of the type I acromions had changed to type II, and the majority of type II acromions remained as type II. By applying acromioplasty to convert to type I acromion, only 1 of the type III acromions remained as type III and the majority changed to type II. Together with ageing, there seems to be the formation of new bone in the site of the resected bone piece. This could show that within years of aggressively applied acromioplasty, the formation of new bone is induced and this does not have a very positive effect on functional scores. There are studies in literature showing that the acromion type changed within years after acromioplasty .
In Group B, where only bursectomy was applied in addition to rotator cuff repair, of the 22 cases with preoperative type I acromion, 20 cases remained as type I postoperatively and 2 changed to type II. All the 20 preoperative type II cases remained as type II postoperatively, and all the 8 preoperative type III cases also remained as type III postoperatively.
In Group C where only rotator cuff repair was applied, all the 17 preoperative type I acromion cases remained as type I postoperatively. The 24 preoperative acromion type II cases all remained as type II postoperatively and the 9 preoperative type III cases also all remained as type III postoperatively.
The acromion morphology is known to change with age and an increase is seen in type III acromion together with ageing. However, the majority of patients with type III acromion are asymptomatic and the presence of type III acromion alone is not sufficient for the formation of impingement syndrome . According to the results of the current study, following intervention to the subacromial area such as acromioplasty, there clearly seems to be a change occurring in the acromion type which is induced by new bone formation.
In conclusion, the change of acromion type is not of great importance in a clinical sense, and over time, the bone which has been taken may form again. No subacromial decompression procedure applied in addition to rotator cuff repair seems to have a positive effect on results. In the presence of acromial spurs only, gentle spur excision can be performed, but the target should never be to change acromion type.
When Group C, where rotator cuff repair only was performed, was compared with the other groups, no significant difference was determined in all the functional scores. Only when evaluations were made in respect of the VAS scores, the scores of the patients with type III acromion were determined as high compared to the other groups and the cases with type I and type II acromion in Group C. However, as can be seen in the same table (Table 3), in the evaluations of postoperative VAS scores according to postoperative acromion types in Groups A and B, the VAS scores of cases with type I acromion were determined as statistically significantly higher than those of cases with type II acromion (p < 0.01).
No significant difference was found between the groups in respect of the postoperative CM and ASES scores, but there were differences in the VAS scores. As the CM and ASES scores provide a more detailed evaluation in respect of both function and pain, they are thought to be more accurate results. That no correlation was seen between VAS score and acromion type can be explained by it being a completely subjective evaluation .