Detriment of subchondral plate violation in antegrade osteochondral procedures-lessons and future direction

The microfracture procedure, introduced in 1994 by Dr. Steadman, involves creating small perforations in the subchondral bone plate to stimulate cartilage regeneration through fibrocartilage formation. Early studies demonstrated its efficacy in improving patient-reported outcomes for small osteochondral defects, particularly in young, active patients. However, its popularity has declined due to poor long-term outcomes and limited indications. Emerging alternatives, such as autologous chondrocyte implantation (ACI) and osteochondral allograft/autograft transplantation (OAT), show superior long-term results. Antegrade procedures like microfracture and drilling aim to release marrow elements to facilitate cartilage repair, but evidence for their efficacy is limited. These techniques can damage subchondral structures, triggering inflammatory and mechanical changes, including subchondral cysts, osteophytes, and reduced bone mineral density. Retrograde drilling, which avoids subchondral plate violation, emerges as a potential solution, promoting revascularization while preserving structural integrity. Despite promising results in subchondral fracture fixation and avascular necrosis, clinical studies are needed to confirm its efficacy for cartilage repair. The key challenge lies in balancing sufficient marrow stimulation with subchondral plate preservation to maintain long-term joint functionality. Future research should focus on understanding the interplay between subchondral plate integrity and cartilage repair durability. Comparative clinical trials are essential to validate retrograde drilling and other evolving techniques as viable alternatives to traditional microfracture and drilling procedures.