Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Two-Year Follow-up of a Prospective Randomized Trial.
BACKGROUND
Randomized controlled trials studying the efficacy and safety of matrix-applied characterized autologous cultured chondrocytes (MACI) versus microfracture (MFX) for treating cartilage defects are limited.


OBJECTIVE
To compare the clinical efficacy and safety of MACI versus MFX in the treatment of patients with symptomatic cartilage defects of the knee.


METHODS
Randomized controlled clinical trial; Level of evidence, 1.


METHODS
Patients enrolled in the SUMMIT (Demonstrate the Superiority of MACI implant to Microfracture Treatment) trial had ≥1 symptomatic focal cartilage defect (Outerbridge grade III or IV; ≥3 cm(2)) of the femoral condyles or trochlea, with a baseline Knee Injury and Osteoarthritis Outcome Score (KOOS) pain value <55. The co-primary efficacy endpoint was the change in the KOOS pain and function subscores from baseline to 2 years. Histological evaluation and magnetic resonance imaging (MRI) assessments of structural repair tissue, treatment failure, the remaining 3 KOOS subscales, and safety were also assessed.


RESULTS
Of the 144 patients treated, 137 (95%) completed the 2-year assessment. Patients had a mean age of 33.8 years and a mean lesion size of 4.8 cm(2). The mean KOOS pain and function subscores from baseline to 2 years were significantly more improved with MACI than with MFX (pain: MACI, 37.0 to 82.5 vs MFX, 35.5 to 70.9; function: MACI, 14.9 to 60.9 vs MFX, 12.6 to 48.7; P = .001). A significant improvement in scores was also observed on the KOOS subscales of activities of daily living (MACI, 43.5 to 87.2 vs MFX, 42.6 to 75.8; P < .001), knee-related quality of life (MACI, 18.8 to 56.2 vs MFX, 17.2 to 47.3; P = .029), and other symptoms (MACI, 48.3 to 83.7 vs MFX, 44.4 to 72.2; P < .001) for patients treated with MACI compared with MFX. Repair tissue quality was good as assessed by histology/MRI, but no difference was shown between treatments. A low number of treatment failures (nonresponders: MACI, 12.5% vs MFX, 31.9%; P = .016) and no unexpected safety findings were reported.


CONCLUSIONS
The treatment of symptomatic cartilage knee defects ≥3 cm(2) in size using MACI was clinically and statistically significantly better than with MFX, with similar structural repair tissue and safety, in this heterogeneous patient population. Moreover, MACI offers a more efficacious alternative than MFX with a similar safety profile for the treatment of symptomatic articular cartilage defects of the knee.
University Medical Center Utrecht, Utrecht, the Netherlands Reconstructive Medicine, Tissue Regeneration, MIRA Institute, University of Twente, Enschede, the Netherlands d.saris@umcutrecht.nl.
Daniel
D
Saris
NIHR Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK.
Andrew
A
Price
District Hospital of Orthopedics and Trauma Surgery, Department of Knee Surgery, Arthroscopy and Sports Traumatology, Piekary Slaskie, Poland.
Wojciech
W
Widuchowski
Chirurgie Arthrose, Sport et Arthroscopie, Polyclinique Saint Roch, Montpellier, France.
Marion
M
Bertrand-Marchand
St Elisabeth Ziekenhuis, Afdeling Orthopedie, Tilburg, the Netherlands.
Jacob
J
Caron
Department of Orthopaedics, Trondheim University Hospital, Trondheim, Norway.
Jon Olav
JO
Drogset
Academisch Ziekenhuis Maastricht, Afdeling Orthopedie, Maastricht, the Netherlands.
Pieter
P
Emans
First Faculty of Medicine, Charles University in Prague, Hospital Bulovka, Prague, Czech Republic.
Ales
A
Podskubka
University Medical Center Utrecht, Utrecht, the Netherlands.
Anika
A
Tsuchida
Genzyme Biosurgery (now Sanofi Biosurgery), Oxford, UK.
Sven
S
Kili
Genzyme Biosurgery (now Sanofi Biosurgery), Cambridge, Massachusetts, USA.
David
D
Levine
Region Halland Orthopedics, Kungsbacka Hospital, Kungsbacka, Sweden.
Mats
M
Brittberg
D000328:Adult; D054544:Arthroplasty, Subchondral / Q000379:methods*; D002358:Cartilage, Articular / Q000293:injuries / Q000601:surgery*; D019902:Chondrocytes / Q000473:pathology / Q000637:transplantation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000473:pathology / Q000601:surgery*; D007719:Knee Joint / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014182:Transplantation, Autologous; D016896:Treatment Outcome; D055815:Young Adult
cartilage repair; clinical outcomes; knee; matrix-applied characterized autologous cultured chondrocytes (MACI) implant; microfracture