J Knee Surg 2012; 25(01): 003-008
DOI: 10.1055/s-0032-1310389
Special Focus Section
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Science and Animal Models of Marrow Stimulation for Cartilage Repair

Lisa A. Fortier
1  Department of Clinical Science, Cornell University, Ithaca, New York
Brian J. Cole
2  Division of Sports Medicine, Department of Orthopedics, Rush University Medical Center, Chicago, Illinois
C. Wayne McIlwraith
3  Orthopaedic Research Center, Department of Clinical Sciences, Colorado State University, Fort Collins, Colorado
› Author Affiliations
Further Information

Publication History

29 February 2012

13 March 2012

Publication Date:
12 April 2012 (online)


Microfracture of subchondral bone to enhance cartilage repair is a popular surgical technique used in human and animal patients. Clinical results with resolution or improvement in pain are promising and last on average for 2 to 3 years. Animal studies aimed at understanding microfracture indicate that the repair tissue continues to remodel toward chondrogenesis for at least a year, but longer term results are not available to gain insight into the mechanism of microfracture function or failure over time. Subchondral bone sclerosis and central lesional osteophyte formation following subchondral bone microfracture have been observed in animal models of microfracture, but studies do not provide any insight into the etiology of these pathologies. The continued maturation of microfracture repair tissue over time supports further investigation of microfracture or microfracture-augmented cartilage repair procedures with caution for the investigator and clinician to be observant for conditions that lead to subchondral bone sclerosis or central osteophyte formation, and what affect these boney reactions have on clinical outcome.