Osteolysis after open shoulder stabilization using a new bioresorbable bone anchor:: A prospective, non-randomized clinical trial

In a clinical trial from August 1996 to March 1998 24 patients with an anterior shoulder instability underwent an open anterior reconstruction which included insertion of a newly developed suture anchor developed by the AO ASIF Development Institute, Davos, Switzerland. This suture anchor was manufactured from bioresorbable polylactide (Poly L/DL-Lactide 70/30) and was designed to be used in combination with commercially available suture materials for the reattachment of the capsulo-labral complex of the shoulder. Four patients did not attend follow-up, and in five patients the follow-up procedure did not follow the protocol, therefore, nine patients had to be excluded from the study. The mean follow-up time was 4.3 months (between 1.5 and 7 months) for the 15 remaining patients. The Constant Score showed a mean improvement of 23 points four months after surgery. Subjective ability scores with regard to work, sport, recreation and sleep improved, and pain diminished. Active painless flexion and strength of abduction increased. In the 15 patients documented by radiology, preliminary analysis of the radiographs taken four months after surgery seemed to indicate a loss of cancellous bone around the implant in seven patients. For this reason, the clinical trial was stopped. Five of the seven were available for follow-up at 26-54 months, but a progressive course of osseous alteration was not identified in any patient. The small number of patients and short follow-up time did not permit meaningful statistical evaluation.