Arthroscopic double-row repair of the rotator cuff: a comparison of bio-absorbable and non-resorbable anchors regarding osseous reaction

Abstract

Purpose: The aim of this study was to analyse the osseous reaction after arthroscopic double-row rotator cuff repair using bio-absorbable poly-L-lactic acid (PLLA) and non-absorbable polyetheretherketone (PEEK) suture anchors. Focus of interest was the appearance of peri-implant fluid and anchor tunnel widening.

Methods: Thirty-six patients were evaluated at final follow-up (16 PLLA and 20 PEEK). Clinical results were acquired by use of the subjective shoulder value, the Constant score and the Western Ontario Rotator Cuff Index. Radiological results were analysed by supraspinatus tendon integrity, footprint coverage, muscular atrophy and fatty infiltration. Furthermore, anchor tunnel expansion was measured, anchor structure and peri-implant fluids graduated.

Results: At 28.4 ± 8.9-month follow-up, clinical outcome was similar (n.s.). MRI investigation revealed osseous reaction in both groups; tunnel widening was 0.9 ± 0.7 mm in PLLA and 0.8 ± 0.6 mm in PEEK anchors (n.s.). Peri-implant fluid was pronounced in PLLA anchors (p < 0.05). Tunnel widening was significantly higher in lateral anchors irrespectively of the material used. Tendon integrity, muscular atrophy, fatty infiltration and footprint coverage were not significantly different (n.s.).

Conclusion: Both materials lead to osseous reaction in this study, whereas consequences of pronounced fluid in PLLA patients remain unclear. Pronounced tunnel widening in lateral anchors leads to the assumption that other causes such as mechanical stress potentially have to be considered when analysing osseous reaction.

Level of evidence: III.