Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Two-Year Follow-up of a Prospective Randomized Trial
Saris D, Price A, Widuchowski W, Bertrand-Marchand M, Caron J, Drogset JO, Emans P, Podskubka A, Tsuchida A, Kili S, Levine D, & Brittberg M. Am J Sports Med. 2014 Published Online First April 8, 2014: doi: 10.1177/0363546514528093
Take Home Message: At 2 years post-surgery, matrix-applied characterized autologous cultured chondrocytes had superior clinical outcomes compared with microfracture surgery for management of large cartilage lesions. Structurally there were no differences between this technique and microfracture at the same 2 year follow-up point.
Knee cartilage lesions can happen in isolation or concomitant to injury and represent a major treatment challenge to long-term knee health. Microfracture and matrix-applied characterized autologous cultured chondrocytes (MACI) are two common surgical approaches utilized to achieve good clinical outcomes (e.g., pain, function) following a knee cartilage lesion. This randomized study compared clinical outcomes at baseline and at a 2 year-follow up among 144 participants with large cartilage knee lesions (> 3cm2) who received either the MACI or microfracture techniques. Despite both groups improving over time, participants who underwent MACI had better improvements at the 2 year follow-up with all 5 KOOS subscores, which are self-reported knee outcome measures, than those that underwent microfracture. MACI participants also included a higher percentage of responders than microfracture. MACI participants also had better improvements in the physical component of the short form health survey than microfracture participants, but both groups had increases in quality of life and overall health status over the 2 year follow up period. A subset of the study population (116 participants) underwent a second arthroscopic biopsy/observation surgery and no differences were found between techniques with tissue assessment (macro- or microscopically).
Both MACI and microfracture participants improved from baseline over the 2 year follow up; however, MACI participants had better self-reported knee clinical outcomes than microfracture patients. This study focused on patients with large cartilage lesions where MFX is sometimes not as successful. It may be interesting to see if the same comparison was done in lesions smaller than 3 cm2 to see if the results would be similar as well. It is interesting that upon visual inspection and biopsy there was no differences detected between the groups. So it remains unclear as to why clinical differences may be seen. Furthermore, 2 years is early to determine any metabolic tissue or structural changes. Following these patients to longer follow-up periods would be of tremendous value to see if there are any ensuing structural changes. It may be that the clinical measures are precursors to impending structural changes. In the meantime, this study supports the use of MACI over microfracture when treating larger cartilage lesions.
Questions for Discussion: Do you have any patients that have undergone either of these 2 surgical techniques? What surgical technique are you seeing used more commonly in your patient population?
Written by: Nicole Cattano
Reviewed by: Jeffrey Driban
Autologous Chondrocyte Implantation for Treatment of Cartilage Defects of the Knee: What Predicts the Need for Reintervention?