Comparative Matched-Pair Analysis of the Injection Versus Implantation of Mesenchymal Stem Cells for Knee Osteoarthritis.
BACKGROUND
The mesenchymal stem cell (MSC)-based tissue engineering approach has been developed to address the problem of articular cartilage repair in knee osteoarthritis (OA). However, the most effective method of MSC application has not yet been established.


OBJECTIVE
To compare the injection and implantation of MSCs in patients with knee OA in terms of clinical and second-look arthroscopic outcomes.


METHODS
Cohort study; Level of evidence, 3.


METHODS
Among 182 patients treated with arthroscopic surgery using MSCs for knee OA from October 2010 to August 2012, patients treated with an injection of MSCs in combination with platelet-rich plasma (injection group; n = 20) were pair-matched with patients who underwent MSC implantation on a fibrin glue scaffold (implantation group; n = 20) based on sex, age, and lesion size. Clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC) score and Tegner activity scale, and cartilage repair was assessed arthroscopically with the International Cartilage Repair Society (ICRS) grading system.


RESULTS
The mean (±SD) IKDC and Tegner activity scores significantly improved from 38.5 ± 9.2 to 55.2 ± 15.0 and from 2.5 ± 1.2 to 3.5 ± 1.2, respectively, in the injection group and from 36.6 ± 4.9 to 62.7 ± 14.1 and from 2.3 ± 0.9 to 3.6 ± 1.1, respectively, in the implantation group at the time of second-look arthroscopic surgery (mean, 12.6 months postoperatively) (P < .001 in all cases). At final follow-up (mean, 28.6 months postoperatively), the mean IKDC and Tegner activity scores in the implantation group had improved further to 64.8 ± 13.4 and 3.9 ± 1.0, respectively (P < .001 and P = .035, respectively), while no significant improvements were found in the injection group (P = .130 and P = .655, respectively). At final follow-up, there was a significant difference in the mean IKDC score between groups (P = .049). Significant correlations between the number of administered MSCs and the postoperative clinical outcomes were found only in the injection group. Significant correlations between the clinical outcomes and the ICRS grades were found in both groups. The ICRS grades were significantly better in the implantation group (P = .041). In the injection group, 2 of the 20 lesions (10%) were grade I (normal), 5 (25%) were grade II (near normal), 8 (40%) were grade III (abnormal), and 5 (25%) were grade IV (severely abnormal). In the implantation group, 6 of the 20 lesions (30%) were grade I, 7 (35%) were grade II, 4 (20%) were grade III, and 3 (15%) were grade IV.


CONCLUSIONS
Utilizing the described method, MSC implantation for knee OA resulted in better clinical and second-look arthroscopic outcomes than an MSC injection.
Center for Stem Cell & Arthritis Research, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, Korea.
Yong Sang
YS
Kim
Center for Stem Cell & Arthritis Research, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, Korea.
Oh Ryong
OR
Kwon
Center for Stem Cell & Arthritis Research, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, Korea.
Yun Jin
YJ
Choi
Center for Stem Cell & Arthritis Research, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, Korea.
Dong Suk
DS
Suh
Center for Stem Cell & Arthritis Research, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, Korea.
Dong Beom
DB
Heo
Center for Stem Cell & Arthritis Research, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, Korea yonggonkoh@gmail.com.
Yong Gon
YG
Koh
D001182:Arthroscopy / Q000379:methods*; D002358:Cartilage, Articular / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D015718:Fibrin Tissue Adhesive; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D065466:Lysholm Knee Score; D008297:Male; D016555:Matched-Pair Analysis; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D053657:Platelet-Rich Plasma; D024162:Second-Look Surgery; D023822:Tissue Engineering / Q000379:methods*; D016896:Treatment Outcome
D015718:Fibrin Tissue Adhesive
implantation; injection; knee; mesenchymal stem cells; osteoarthritis