Promoting hematoma-like tissue formation in arthroscopic rotator cuff repair: impact of a bioinductive collagen...

Hematomas, rich in platelet-derived growth factors, are vital in tendon-bone healing. Reportedly, larger hematoma-like tissue (HLT) surrounding the repaired tissue at 6-8 weeks after rotator cuff repair on T2-weighted magnetic resonance imaging effectively predicts structural outcomes (Sugaya classification type 1) at 6 months post-operatively. Recent studies explored the use of a reconstituted type I bovine collagen bioinductive implant derived from the bovine Achilles tendon to improve healing rates and tissue thickness, leading to favorable clinical outcomes. Therefore, we aimed to evaluate whether using this collagen implant to cover the lateral side of the sutured rotator cuff enhances the HLT size, formation, and maintenance at 6-8 weeks post-operatively.

In this retrospective cohort study, we analyzed patients who underwent arthroscopic rotator cuff repair using the surface-holding method. Fifty-eight patients were treated without implants (H group), while 58 received bioinductive collagen implants (REGENETEN; Smith & Nephew, Andover, MA, USA) (R group). Magnetic resonance imaging was performed at 1 week and 6-8 weeks post-operatively to evaluate HLT thickness, classified as grades 1 (no HLT), 2 (HLT not exceeding the line connecting the cuff surface and the lateral edge of the greater tuberosity), or 3 (HLT exceeding the line). Retears at 6-8 weeks post-operatively were also assessed.

At 1 week post-operatively, 55.2% of the H group and 60.3% of the R group were classified as grade 3, with no significant difference (P = .71). At 6-8 weeks, 22.4% and 63.8% of the H and R groups, respectively, were classified as grade 3 (P < .05). Moreover, 40.6% and 77.1% of the H and R groups, respectively, maintained grade 3 from week 1 to 6-8 weeks post-operatively (P < .05). In addition, in the H group, no case changed from grade 1 or 2 to grade 3, whereas 37.5% of cases in the R group changed from grade 1 to grade 3 and 50% changed from grade 2 to grade 3. Furthermore, the R group had fewer cases in which the HLT became thinner, disappeared, or experienced a retear compared to the H group (P < .05).

Implanting a reconstituted type I bovine collagen bioinductive implant in arthroscopic rotator cuff repair using the surface-holding method helps to preserve and enhance HLT thickness, with a higher proportion of patients achieving grade 3 HLT at 6-8 weeks post-operatively. These findings suggest the potential of collagen implants to improve tendon-bone healing and structural outcomes.