Editorial Commentary: Bone Tunnel Grafting for Two-Stage Anterior Cruciate Ligament Revision and the Meaning of Life for an Arthroscopic Surgeon.

Accurate bone tunnel filling in a 2-staged anterior cruciate ligament revision is indubitably fundamental for a successful outcome. Bone autograft is commonly employed and it is usually harvested from the iliac crest: this requires longer surgical time, and donor-site morbidity following bone harvest is a well-known problem. Therefore, strategies to minimize or abolish it have been attempted: the use of allografts may seem promising, but their use is associated with high costs and strict regulatory limitations. Bony substitutes instead represent a new and potentially effective solution: they could help surgeons to fill bone tunnels in an easier and faster way that elicits satisfactory lamellar bone formation within the tunnels, and their use is associated with fewer postoperative complications, such as pain and local hematoma. Evidence from literature suggests that this approach could provide significant advantages over traditional autograft harvesting, with comparable outcomes in terms of bone formation and integration, allowing a correct tunnel placement during revision surgery.