PLGA Conical Nail Fixation for Acetabular Chondrolabral Delamination in Femoroacetabular Impingement Promotes Cartilage and Labrum Regeneration in a Porcine Model.

Abstract

Acetabular chondrolabral delamination (ACD) is one of the most common hip cartilage injuries. However, there are very limited clinical treatments for this injury. To evaluate the effectiveness of poly (lactic-co-glycolic acid) (PLGA) conical nail fixation in the treatment of acute and chronic ACD in a porcine model. Controlled laboratory study. In this study, 24 pigs underwent surgically induced delamination of the chondrolabral junction. Pigs were randomly divided into 3 groups: the control group (delaminated chondrolabral junction without treatment), ACD acute refixation (ACDA) group (delaminated chondrolabral junction fixed with a PLGA nail), and ACD chronic refixation (ACDC) group (placement of a nonabsorbable spacer at the stripped chondrolabral junction for 6 weeks before fixation with a PLGA nail). Porcine specimens underwent magnetic resonance imaging (MRI), hematoxylin and eosin staining, safranin O/fast green (SO/FG) staining, immunohistochemistry examination (collagen 1, collagen 2, and collagen 10), and immunofluorescence examination (<i>SOX9</i> and <i>aggrecan</i>) to evaluate the chondrolabral regeneration at 6 and 12 weeks postoperatively. MRI showed focal discontinuity of cartilage and fluid located between the acetabular cartilage and subchondral bone plate in the control group. The acetabular cartilage stained with SO/FG showed significantly more proteoglycan deposition at 12 weeks in the ACDA group than in the control group (<i>P</i> = .0109) and ACDC group (<i>P</i> = .0484). In accordance with the results of the SO/FG and collagen 10 staining, the aggrecan of the femoral head at 6 and 12 weeks was upregulated in the ACDA group (<i>P</i> < .0001) and downregulated in the ACDC group (<i>P</i> < .0001). PLGA conical nail fixation achieved a good treatment outcome on MRI and histological evaluations. Early treatment upregulated the expression levels of SOX9 and aggrecan and promoted proteoglycan deposition. The PLGA conical nail fixation technique may be a viable and effective treatment approach for patients with ACD in clinical practice.