Effect of accelerated weightbearing after matrix-associated autologous chondrocyte implantation on the femoral condyle: a prospective, randomized controlled study presenting MRI-based and clinical outcomes after 5 years.
BACKGROUND
Long-term effects of different weightbearing (WB) modalities after matrix-associated autologous chondrocyte implantation (MACI) on changes in knee articular cartilage and clinical outcomes are needed to establish more evidence-based recommendations for postoperative rehabilitation.


OBJECTIVE
There will be no differences between accelerated WB compared with delayed WB regarding knee articular cartilage or patient self-reported knee function or activity level 5 years after MACI. Furthermore, significant correlations between magnetic resonance imaging (MRI)-based outcomes and patient-reported outcome measures 5 years postoperatively will exist.


METHODS
Randomized controlled trial; Level of evidence, 1.


METHODS
After MACI, 31 patients (23 male, 8 female) were randomly assigned to the accelerated WB group (AWB group) or to the delayed WB group (DWB group). With the exception of time and increase to full WB, both groups underwent the same rehabilitation program. The AWB group was allowed full WB after 6 weeks and the DWB group after 10 weeks. Assessments were performed 3 months, 2 years, and 5 years postoperatively, but this long-term follow-up study only included changes from 2 to 5 years postoperatively. The magnetic resonance observation of cartilage repair tissue (MOCART) score (primary outcome), the MRI-based variables of bone edema and effusion, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Tegner scale were included. In addition, the association between MRI-based outcomes and the KOOS at 5 years postoperatively was investigated.


RESULTS
There was a significant decrease in the MOCART score and a significant increase in bone edema 2 and 5 years postoperatively but no significant group differences. The only significant correlation between the MRI-based variables and the KOOS was found for bone edema and the KOOS subscale of pain (r=-0.435, P<.05) at 5-year follow-up.


CONCLUSIONS
There were no significant differences in the MRI-based or clinical outcomes between the AWB group and DWB group 5 years after MACI. While the clinical outcomes remained stable, a decline of the MRI-based findings was observed between 2 and 5 years postoperatively. Furthermore, a significant association between bone edema and pain was found. No occurrence of unintended effects was observed.
Norwegian Research Center for Active Rehabilitation, Department of Sport Medicine, Norwegian School of Sport Sciences, Oslo, Norway Department of Health and Social Sciences, St Poelten University of Applied Sciences, St Poelten, Austria office@wondrasch.at.
Barbara
B
Wondrasch
Department of Health and Social Sciences, St Poelten University of Applied Sciences, St Poelten, Austria.
May-Arna
MA
Risberg
Department of Traumatology, Medical University of Vienna, Vienna, Austria.
Lukas
L
Zak
Department of Traumatology, Medical University of Vienna, Vienna, Austria.
Stefan
S
Marlovits
Department of Traumatology, Medical University of Vienna, Vienna, Austria.
Silke
S
Aldrian
D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D018771:Arthralgia / Q000209:etiology; D001847:Bone Diseases / Q000209:etiology; D002358:Cartilage, Articular / Q000293:injuries*; D019902:Chondrocytes / Q000637:transplantation*; D004487:Edema / Q000209:etiology; D005260:Female; D005269:Femur; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000534:rehabilitation / Q000601:surgery*; D065466:Lysholm Knee Score; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D013177:Sports; D013997:Time Factors; D014182:Transplantation, Autologous / Q000009:adverse effects; D016474:Weight-Bearing; D055815:Young Adult
MRI; matrix-associated autologous chondrocyte implantation; rehabilitation; weightbearing