MRI graduation of osseous reaction and drill hole consolidation after arthroscopic Bankart repair with PLLA anchors and the clinical relevance.

Abstract

Conventionally, radiography studies revealed prolonged glenoidal drill hole visibilities with an unclear influence to the clinical outcome after arthroscopic Bankart repair using Poly-Laevo-Lactic-Acid (PLLA) anchors. The primary aim of the present study was the separated assessment of drill hole consolidation (DHC) and the concomitant osseous reaction (OR) of the glenoidal bio-degradation process in new specific magnetic resonance grading systems. In accordance with the specific DHC and the OR graduation, the clinical relevance was the secondary focus. Twenty-eight patients with arthroscopic Bankart repair using knotless PLLA anchors were prospectively followed and analyzed using a clinical scoring system (3, 6, 15 and 32 months). The T2-weighted OR and T1-weighted DHC were assessed using specific magnetic resonance imaging grading protocols (15 and 32 months). Longitudinal assessments revealed successive clinical status improvements over time (32 months: Rowe 95.7 ± 3.8; Walch-Duplay 93.8 ± 6.6; Constant 93.9 ± 4.5; ASES 93.8 ± 6.9; DASH 28.6 ± 7.2; NAS(pain) 1.1 ± 1.3; NAS(function) 1.3 ± 1.4). The initial OR level regressed over the 15-32 month period while the DHC showed significant drill hole reductions (P < 0.05). The inferior glenoid revealed a significantly increased bio-degradation capacity (P < 0.05) with drill hole enlargements in 14.3%. Neither the OR nor the drill hole enlargements influenced the clinical status. In no case were clinical or radiologic signs for a foreign body reaction. Knotless bio-anchors provide secure glenoidal fixation for Bankart repair without any specific clinical or MR evidence of an inflammatory response. The clinical status remained unaffected by the bio-degradation process. IV.