Effect of Subchondral Drilling on the Microarchitecture of Subchondral Bone

Abstract

The subchondral bone remains fragile after subchondral drilling for longer durations than previously expected. Further evaluations of structural subchondral bone parameters of patients undergoing marrow stimulation are warranted.

Alterations of the subchondral bone in osteochondral repair – translational data and clinical evidence

“…In sheep, elevation of the subchondral bone plate beyond the former level of the tidemark was reported for chondral defects treated by microfracture after 1 year (Dorotka et al, 2005). While this was not confirmed in another sheep model of drilled full-thickness cartilage defects after 6 months (Orth et al, 2012b), in horses 50 % of drilled chondral defects exhibited elevation of the subchondral bone into the defect site (Shamis et al, 1989) Lajeunesse et al, 1999), possibly due to metaplasia of the deep layer of the articular cartilage (Shapiro et al, 1993). Several investigations speculated that such an upward migration of the subchondral bone plate might be the primary cause for subsequent cartilage degeneration in osteoarthritis (Bullough and Jagannath, 1983;Green et al, 1970;Jeffery, 1973;Radin et al, 1991).…”

“…1). There is accumulating experimental evidence for these subchondral bone alterations in small (Aroen et al, 2006;Chen et al, 2009;Chen et al, 2011a;Heir et al, 2012;Marchand et al, 2011;Marchand et al, 2012;Nam et al, 2004;Qiu et al, 2003) and large preclinical animal models (Dorotka et al, 2005;Frisbie et al, 1999; Hanie et al, 1992;Hoemann et al, 2005;Howard et al, 1994;Ishimaru et al, 1992;Lane et al, 2004;Orth et al, 2012b;Vachon et al, 1986) of cartilage defects. Supporting these findings, such pathological alterations were also reported in up to one third of patients treated with microfracture (Kreuz et al, 2006;Mithoefer et al, 2005; Saris et al, 2009).…”

“…Besides constituting the new cartilaginous repair tissue, mesenchymal cells in the deeper regions of the defect also differentiate into osteocytes (Jackson et al, 2001;Shapiro et al, 1993), resulting in the formation of immature bone that usually restores the original level of the subchondral bone in a distinct chronological order (Orth et al, 2012a). Over time, however, this new subchondral bone may advance toward the joint space, and intralesional osteophytes might form (Orth et al, 2012b). …”

“…In the sheep model, intralesional osteophyte formation was observed after 3 months in all temporomandibular joints that had received perforation of the subchondral bone plate (Ishimaru et al, 1992). Recent data revealed a 26 % incidence of intralesional osteophyte formation 6 months following drilling of full-thickness chondral defects of ovine medial femoral condyles with immediate and full weight-bearing postoperatively (Orth et al, 2012b) (Table 1). …”

No Effect of Hole Geometry in Microfracture for Talar Osteochondral Defects

“…One animal study suggests that the depth of subchondral perforation influences the degree of fill and quality of repair tissue [7]. Other research indicates that there is a difference in bone structure and degree of bone necrosis between drilling and microfracture [8,29].…”