Magnetic resonance appearance of bioabsorbable anchor screws for double row arthroscopic rotator cuff repairs

Abstract

Background:Little is known about the bioabsorbable, anchor related postoperative changes in rotator cuff surgery, which has become more popular recently. The purpose of the present study was to use magnetic resonance imaging (MRI) to analyze the degradation of bioabsorbable anchors and to determine the incidences and characteristics of early postoperative reactions around the anchors and their mechanical failures.Materials and Methods:Postoperative MRIs of 200 patients who underwent arthroscopic rotator cuff repair were retrospectively analyzed. The tissue reactions around the bioanchors included fluid accumulations around the anchor, granulation tissue formation and changes in the condition of the surrounding osseous structure. The condition of the bioanchor itself was also examined, including whether the bioanchor failed mechanically. In the case of mechanical failure, the location of the failure was noted. Serial MRIs of 18 patients were available for analysis.Results:The total number of medial row bioanchors was 124, while that of the lateral row was 338. A low signal intensity rim suggestive of sclerosis surrounded all lateral row bioanchors. Ninety three lateral row bioanchors (27%) showed a rim with signal intensity similar to or less than that of surrounding bone, which was granulation tissue or foreign body reaction (FBR). Similar signal intensity was seen around nine medial row bioanchors (7%). Fluid accumulation was seen around 4 lateral row bioanchors (1%) and around 14 medial row bioanchors (11%). Five lateral row bioanchors showed the breakage, while there was none in the medial row bioanchors. There were nine cases with a cuff re-tear (4.5%). There was no evidence of affection of glenohumeral articular surfaces or of osteolysis around any bioanchor. In serial MRI, there was no change in appearance of the bioanchors, but the granulation tissue or FBR around four bioanchors and the fluid around one bioanchor showed a decrease in successive MRI.Conclusion:This study highlights the normal and adverse reactions to Bioabsorbable anchors that surgeons can expect to see on MRI after rotator cuff repairs.

Serial clinical and MRI examinations after arthroscopic rotator cuff reconstruction using double-row technique

“…It is interesting to note that the bone edema area began to decrease slightly earlier in the work by Stanke et al and colleagues compared to the results of the present study, although the same resorbable anchors were used in both studies. Pawaskar et al [23] also analysed the characteristics of bioresorbable anchors after rotator cuff repair. Fluid accumulation was seen in about 11% of the medial anchors, which points to fluid collection or bone marrow edema.…”

Periimplant osteolysis does not affect the outcome of rotator cuff repair: a systematic review and meta-analysis

“…However, the criteria for PIO were different from those of other studies. Pawaskar et al [32] evaluated peri‐anchor fluid collection and retear rate. However, the definition of PIO was different from those in other articles, and the relationship between PIO and retear was not clearly described.…”

“…Although PIO has been continuously reported, consensus on the nomenclature of the lesion has not been achieved. Numerous authors have reported PIO with various names depending on the features on radiological indings or suggested pathophysiologies, including peri-anchor luid collection, peri-anchor cysts, periimplant luids, foreign body reactions, radiolucent rings, osteolysis, and osseous reactions [18,21,23,[31][32][33]. These inconsistencies should be resolved, as they lead to a diiculty in searching for previous articles and designing further research.…”

The Repaired Rotator Cuff: MRI and Ultrasound Evaluation

“…Ten months after rotator cuff repair, oblique coronal IR (c) and oblique sagittal PD (d) images demonstrate somewhat irregular and slightly hyperintense supraspinatus tendon fibers (arrows) inserting onto the greater tuberosity, without a fluid filled gap to suggest a re-tear. Suture anchors (dashed arrows) are noted within the greater tuberosity foreign body granulomas in the susceptible host [32][33][34]. On MRI, prominent and persistent bone marrow edema around the anchors associated with bony resorption is suspicious for an inflammatory reaction ( Fig.…”

“…On MRI, prominent and persistent bone marrow edema around the anchors associated with bony resorption is suspicious for an inflammatory reaction ( Fig. 7a-c) [33]. The imaging features can overlap with infection particularly if these are accompanied by soft tissue edema, subacromial bursitis, and synovitis.…”