Our results reveal no significant difference between group A and B concerning characters of the 10 mm and 15 mm supraspinatus tendon displacement and load to failure test. This displacement also indicates a single knotless-anchor for Bursal-side Ellman III PTRCTs is a useful technique that we could choose. This is the first study presenting a similar biomechanical effect with a double row to the best of our knowledge.
As far as we all know, DR rotator cuff repair is the most common and widely used clinical technique. Current literature works demonstrate that the biomechanical properties of a DR rotator cuff repair are superior to a single-row repair (SR). Additionally, it is evident from the reviewed researches that the DR technique has reconstructed the anatomic footprint of the rotator cuff significantly better than SR repairs [18, 19]. Compared with the DR group's load to failure results, there was no significant difference between the two groups (P > 0.05). This also revealed the single Knotless-anchor with 2 Ethicon 2# could also reconstruct an anatomic footprint and provide biomechanical properties as DR rotator cuff repair. Moreover, regarding the 10 mm and 15 mm displacement of the supraspinatus, our results demonstrate a single Knotless-anchor could withstand the horizontal traction of biomechanical power to achieve a balance. On the other hand, concerning the supraspinatus displacement on 3 mm and 5 mm, the DR group was presented superior biomechanical properties. This finding revealed that the suture anchor in the medial-row provided a firm power and reduced the medial rotator cuff's micro-motion.
Although the single knotless-anchor for Bursal-side Ellman III PTRCTs with two Ethicon 2# is a simple, cheap, and effective technique, the essence of the substance of our method is an in situ repair (transtendon repair). To be specific, compared with the conversion repair with DR, Gonzalez-Lomas demonstrated that the ultimate failure load was significantly higher in the transtendon repair group . Other primary research also indicated that transtendon repair was presented a higher ultimate failure load than double-row repair following full-thickness conversion . These studies have similar effects on my findings, which also indicate the biomechanical advantages of tendon repair. Moreover, clinically transtendon repair has presented to be more effective than conversion to a full-thickness tear with the subsequent repair. Hytham Salem demonstrated that an in situ repair technique with double-row suture anchors in repairing bursal-sided PTRCTs provided a better fixation of the rotator cuff tissue while preserving the anatomy of the medial footprint . This is a good study, which inspires me to start such research. Therefore, our technique for Bursal-side Ellman III PTRCTs is a simple, cheap, and effective technique that we could choose.
There are some surgical operation indications that we should follow by the use of this technique. There were three cases of sutures pulling through the tendon . This revealed that 2 Ethicon 2# sutures had a higher risk of cutting supraspinatus. Furthermore, theoretically, this might increase the failure of fixation or re-rupture rates. On the other hand, Ethicon 2# sutures may cover weak areas in the tendon and decrease load to failure test. Therefore, the failure test does not simulate the natural failure biomechanics. So, several surgical indications of this method were mandatory: (i)Patients cannot bear the medical expenses and have cheap health insurance; (ii) Patients have a good elasticity or high quality of the supraspinatus under the arthroscopic debridement; (iii) The lateral row part of greater tuberosity bone density is normal;(iv) Patients have younger age than 60 years.
To sum up, there are various advantage of ours method as follows: (i) The bursal layer–only repair could produce the same clinical outcomes or structural integrity all-layers repair ; (ii) We retain the superior capsule, which provides the superior glenohumeral stability and has often been overlooked ; (iii) We also retain the cable(Fig. 2.C), which is the primary load-bearing structure within the supraspinatus ;(iv) The single knotless-anchor for Bursal-side Ellman III PTRCTs is a simple, cheap, and effective technique that benefit both doctors and patients;(v) It is no necessary to consider the problem of the osteoporosis in the medial row.
However, our study also had some limitations. Firstly, with the lack of human samples, we only employed some 16 fresh-frozen specimens. We will employ more cadaveric shoulders in a future study. Secondly, the MRI should be employed to assess the specimen modal. Thirdly, with a limited number of available cadaver specimens, not all known fixation techniques such as a standard suture bridge were used in our study. Fourthly, the lesion of the cable group should employ for the next research.