The purpose of this study was to evaluate outcomes of screw-type and coil-type open architecture suture anchors with respect to bony ingrowth, release of biologic markers and patient-reported outcome measures when used in rotator cuff repair (RCR).
Forty patients undergoing arthroscopic RCR for full thickness rotator cuff tears were enrolled and prospectively randomized to receive a screw-type (19 patients) or a coil-type (21 patients) suture anchor for the medial row during repair. All repairs used a transosseus-equivalent configuration with footprint anchors laterally. Marrow elements released during surgery were evaluated for 8 cytokine markers (IGF-1, FGF-2, BMP-7, BMP-2, PDGF-AA, PDGF-BB, EGF, and VEGF). Post-operative CT-scans were performed at 6months. Range of motion, strength, and validated patient reported outcome measures (Simple Shoulder Test, Single Assessment Numeric Evaluation, Visual Analog Score, American Shoulder and Elbow Surgery Score) were gathered before the operation and after at 6months and 1year.
Bone mineral density surrounding the coil-type anchor was significantly greater than the screw-type anchor (p=0.005). Bone mineral density within the coil-type and screw-type anchors was comparable (p=0.527); however, the coil-type anchor demonstrated a larger amount of total bone mineral mass (mg) within the anchor due to its larger volume (p<0.01). Marrow elements released at the repair site were similar between groups (p>0.05). Post-operatively no statistically significant difference was found between groups for clinical outcomes measures at 6months or 1year. Retear and complication rates were similar between groups (p>0.05).
Both coil-type and screw-type anchors can be reliably utilized for RCR and produce similar clinical outcomes. Coil-type anchors resulted in superior bony growth surrounding the anchor and a larger total bone mineral mass within the anchor due its larger volume.