title: Histomorphochemical comparison of microfracture as a first-line and a salvage procedure: is microfracture still a viable option for knee cartilage repair in a salvage situation?
abstract: Microfracture is considered as the first-line procedure for knee cartilage repair, but the results of microfracture seem less predictable and rather controversial in a salvage situation. Thus, the purpose of the study was to histomorphochemically compare microfracture as a salvage procedure with microfracture as a first-line procedure in a rabbit model. We hypothesized that microfracture in a salvage situation would result in histomorphochemically inferior cartilage repair compared to microfracture as a first-line procedure, and the inferiority would be attributed to less migration of reparable marrow cells to the defect due to destruction of microarchitecture of the subchondral bone. Thirty-six New Zealand white rabbits were divided into three groups: (i) untreated full-thickness chondral defect, (ii) single microfracture treatment (first microfracture group), and (iii) repeated microfracture in 8 weeks after the first procedure (second microfracture group). In each group, rabbits were sacrificed at the end of 8 weeks, and osteochondral specimens at the repair sites were obtained for histomorphochemical analysis. Results showed that microfracture as a salvage procedure resulted in overall inferior cartilage repair histomorphochemically compared with microfracture as a first-line procedure, which correlated with deteriorative changes in the quality of underlying subchondral bone rather than intrinsic incapability to recruit the reparative cells in the defect area. In conclusion, although a comparable number of reparable cells and a mechanically weakened subchondral bone are anticipated, more study is necessary to clearly determine when a microfracture should be performed in a situation.
authors.affiliation: Department of Molecular Science and Technology, Ajou University, Suwon, Korea.
authors.forename: Minh-Dung
authors.initials: MD
authors.lastname: Truong
authors.forename: Jun Young
authors.initials: JY
authors.lastname: Chung
authors.forename: Young Jick
authors.initials: YJ
authors.lastname: Kim
authors.forename: Long Hao
authors.initials: LH
authors.lastname: Jin
authors.forename: Byoung Ju
authors.initials: BJ
authors.lastname: Kim
authors.forename: Byung Hyune
authors.initials: BH
authors.lastname: Choi
authors.forename: Byoung-Hyun
authors.initials: BH
authors.lastname: Min
mesh_terms: D000818:Animals; D054544:Arthroplasty, Subchondral / Q000009:adverse effects*; D015519:Bone Density; D002356:Cartilage / Q000293:injuries* / Q000473:pathology / Q000601:surgery; D003114:Colony-Forming Units Assay; D007718:Knee Injuries / Q000601:surgery*; D011817:Rabbits; D012086:Reoperation / Q000009:adverse effects; D016879:Salvage Therapy / Q000379:methods*; D014945:Wound Healing
keywords: bone marrow stimulation; cartilage repair; knee; mesenchymal stem cell; microfracture; subchondral bone