The authors describe a case of a 25 year old male who suffered recurrent shoulder dislocations after a symptom-free period following an initial arthroscopic shoulder stabilisation using PEEK suture anchors to repair the Bankart and SLAP lesions. The MRI and CT scans showed perianchor radiolucency around all of the previously placed PEEK suture anchors. It is believed that his recurrent shoulder instability was related to this radiological finding although the exact pathomechanism of the osteolysis is not clear. To our knowledge, this is the first reported case of perianchor radiolucency after the use of a PEEK suture anchor.
As the use of glenoid suture anchors in arthroscopic and open reconstruction, for instability after Bankart lesions of the shoulder, increases, an emerging problem has been the incidence of glenoid rim fractures through suture drill holes. Very little is known regarding the effect of the Hill-Sachs lesion on the glenoid's susceptibility to fracture and how drill hole location can further affect this. This study used finite element modeling techniques to investigate the risk of fracture of the glenoid rim in relation to variable sized Hill-Sachs defects impacting on the anterior glenoid edge with suture anchor holes placed in varying positions. The distribution of Von Mises (VM) stresses and the factor of safety (FOS) for each of the configurations were calculated. The greatest peak in VM stresses was generated when the glenoid was loaded with a small Hill-Sachs lesion. The VM stresses were lessened and the FOS increased (reducing likelihood of failure) with increasing size of the Hill-Sachs lesion. Placement of the suture drill holes at 2 mm from the glenoid rim showed the highest risk of failure; and when combined with a medium sized Hill-Sachs lesion, which matched the central line of the drill holes, a potentially clinically significant configuration was presented. The results of this study are useful in assisting the surgeon in understanding the interaction between the Hill-Sachs lesion size and the placement of suture anchors with the purpose of minimizing the risk of subsequent rim fracture with new injury.