This 2009 systematic review by Mithoefer et al. analyzed 28 studies (3122 patients) to evaluate the clinical efficacy of microfracture for articular cartilage repair in the knee. It assessed short- and long-term functional outcomes, MRI repair quality, histology, and complication rates across all available clinical literature through 2007. The goal was to define what microfracture actually achieves — and which patients benefit most.
Microfracture was routinely used as first-line treatment for nearly any chondral defect, with limited understanding of which patients would maintain their gains. This review established that the 2-year functional peak is real — but so is the subsequent decline in a large proportion of patients.
When you are selecting a patient for microfracture, the favorable profile is narrow: age under 40, symptoms under 12 months, defect under 4 cm² (under 2 cm² in athletes), BMI under 30, Tegner score above 4, and no prior surgery. Outside this profile, expect less predictable results and rising failure rates after 2 years.
The most consequential number in this paper is the ACI failure rate: 17% without prior microfracture, 50% with it. Do not default to microfracture as a temporizing measure in a young, active patient who may need ACI later. The first procedure shapes whether the second one succeeds.
Routine postoperative MRI is recommended to catch poor defect fill early, enabling timely revision before irreversible functional decline occurs.
This 2009 systematic review by Mithoefer et al. analyzed 28 studies (3122 patients) to evaluate the clinical efficacy of microfracture for articular cartilage repair in the knee. It assessed short- and long-term functional outcomes, MRI repair quality, histology, and complication rates across all available clinical literature through 2007. The goal was to define what microfracture actually achieves — and which patients benefit most.
Microfracture was routinely used as first-line treatment for nearly any chondral defect, with limited understanding of which patients would maintain their gains. This review established that the 2-year functional peak is real — but so is the subsequent decline in a large proportion of patients.
When you are selecting a patient for microfracture, the favorable profile is narrow: age under 40, symptoms under 12 months, defect under 4 cm² (under 2 cm² in athletes), BMI under 30, Tegner score above 4, and no prior surgery. Outside this profile, expect less predictable results and rising failure rates after 2 years.
The most consequential number in this paper is the ACI failure rate: 17% without prior microfracture, 50% with it. Do not default to microfracture as a temporizing measure in a young, active patient who may need ACI later. The first procedure shapes whether the second one succeeds.
Routine postoperative MRI is recommended to catch poor defect fill early, enabling timely revision before irreversible functional decline occurs.