Arthroscopic remplissage with all-suture anchors causes cystic lesions in the humerus: a volumetric CT study of 55 anchors.

PURPOSE To evaluate with computed tomography (CT) the incidence of implant-related osteolysis after implantation of two types of all-suture anchors during remplissage for the management of Hill-Sachs lesions in shoulder instability. METHODS Single-cohort, observational study with a minimum of 12 months follow-up. Twenty-five participants (19 males and 6 females; mean age 37.4 years [SD: 11.6]) with Hill-Sachs lesions requiring remplissage were evaluated with a CT performed a mean of 14.1 [3.74] months after surgery. Fifty-five all-suture anchors (19 2.3 mm Iconix and 36 1.7 mm Suturefix) were used. The volume of the bone defects was measured in the CT. Every anchor was classified into one of four groups: (1) no bone defect. (2) Partial bone defect (bone defects smaller than the drill used for anchor placement). (3) Tunnel enlargement (bone defect larger than the drill volume but smaller than twice that volume). (4) Cystic lesion (bone defect larger twice the drill volume). RESULTS No bone defect was identified in only two anchors (3.6%, 95% CI 0.4-12.5%). A partial bone defect was found in eight anchors (14.5%, 95% CI 6.5-26.7%). In 35 anchors (63.6%, 95% CI 49.6-76.2%), there was enlargement of the bone defect that was smaller than 200% the size of the drill used. Ten anchors caused bone defects larger than twice the size of the drill used (18.2%, 95% CI 9.1-30.9%). The defect size was a mean of 89 mm3 (SD: 49 mm3, minimum 0 mm3, maximum 230 mm3). CONCLUSION When using all-suture anchors in arthroscopic remplissage during instability surgery, relevant bone osteolytic defects are common at 1-year-follow-up. Cystic defects larger than twice the volume of the resected bone during implantation develop in one in six anchors and significant tunnel widening will develop in another three out of five anchors. This bone loss effectively increases the size and depth of the Hill-Sachs lesions but does not seem to affect short-term clinical outcomes. LEVEL OF EVIDENCE Level IV.