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

PURPOSE: 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.
METHODS: 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).
RESULTS: 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.
CONCLUSION: 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. LEVEL OF EVIDENCE: IV.