Full length article Long-term follow-up evaluation of autologous chondrocyte implantation for symptomatic cartilage lesions of the knee: A single-centre prospective study M. Berruto*, P. Ferrua, S. Pasqualotto, F. Uboldi, A. Maione, D. Tradati, E. Usellini SSD Chirurgia Articolare del Ginocchio, Istituto Ortopedico Gaetano Pini, Milan, Italy A R T I C L E I N F O Article history: Accepted 2 August 2017 Keywords: Autologous chondrocyte implantation (ACI) Cartilage Chondral lesions Scaffold Long-term follow-up A B S T R A C T Introduction: Autologous Chondrocyte Implantation (ACI) has been the first technique in reconstruction of a valid articular surface. The aim of this study was to evaluate clinical results of this technique at an average follow up of 162 Æ 27 months (range 88–208) in a group of patients who underwent ACI. Materials and methods: 32 patients were operated between 1997 and 2007 for chondral lesions or osteochondritis dissecans of the knee. Mean size of the defect was 5.48 cm 2 Æ 1.53 (range 2–9). Nine patients were treated with I generation technique and 23 with II generation. All patients were evaluated with Subjective IKDC and Tegner Activity Scales for clinical outcomes and with EQ-VAS for a quantitative measure of health after intervention, starting from pre-operative period and at regular follow up (minimum 88 months-maximum 208 months). Results: A significant increment of all scores was noticed comparing preoperative and postoperative results. In particular medium IKDC score increased from 40.3 Æ 9.6 in preoperative evaluation to 74.2 Æ 11.6 at one year (p < 0.00001) and to 83.9 Æ 10.4 at 5 years follow up (p < 0.001). Mean IKDC values at the last follow-up were 80.3 Æ 14.2, showing no statistical differences with those obtained at five-year follow-up. Tegner Activity Scale values increased from 2.8 Æ 1.1 preoperatively to 4.1 Æ1.1 (p < 0.0001) after one year and to 6 Æ 1.1 at five years (p < 0.0001). Mean Tegner Activity Scale values decreased to 4.8 Æ 1.4 at the last follow-up. EQ-VAS evaluation showed superposable results comparing the 5 years evaluation with the ones at a medium follow up of 162 Æ 27 months. Discussion: The most important finding is the reliability at long-term of ACI technique, which in our series gave excellent clinical results. No statistical differences were observed between first- and second- generation. Clinical outcomes were significantly better for defects in the femoral condyles, influenced by age (worse results over 30 years old). Conclusions: ACI represents a valid technique for chondral and osteochondral lesions of the knee in a population heterogeneous for age, sex and activity level with good results even at a long term follow up. © 2017 Elsevier Ltd. All rights reserved. Introduction First described by Brittberg in 1994 [1], autologous chondrocyte implantation (ACI) is considered a valid technique for the treatment of full-thickness articular cartilage defects in the knee. However, despite giving good results at medium- to long-term follow-up, it is now being used less than before, mainly for economic reasons and because it is a two-step procedure. The original technique (first-generation ACI), which involved the use of a periosteal flap to cover the defect, underwent several modifications following the introduction of biodegradable scaf- folds, aimed at reducing the number and severity of complications. These modifications led to the emergence of so-called second- and third-generation ACI. The literature contains studies that encourage use of this technique on the strength of its good short- to medium- and long- term results [2–6], and a few that have analysed even longer-term outcomes (at a mean follow-up of at least 10 years) [7–11]. The aims of this study were to describe long-term functional outcome after ACI, to investigate its failure rate, and to identify possible prognostic factors liable to influence the results of this procedure. The hypothesis was to evaluate whether ACI would * Corresponding author at: SSD Chirurgia Articolare del Ginocchio, Istituto Ortopedico Gaetano Pini, P.za Cardinal Ferrari 1, 20122 Milan, Italy. E-mail address: massimo.berruto@fastwebnet.it (M. Berruto). http://dx.doi.org/10.1016/j.injury.2017.08.005 0020-1383/© 2017 Elsevier Ltd. All rights reserved. Injury, Int. J. Care Injured xxx (2017) xxx–xxx G Model JINJ 7335 No. of Pages 5 Please cite this article in press as: M. Berruto, et al., Long-term follow-up evaluation of autologous chondrocyte implantation for symptomatic cartilage lesions of the knee: A single-centre prospective study, Injury (2017), http://dx.doi.org/10.1016/j.injury.2017.08.005 Contents lists available at ScienceDirect Injury journal homepa ge: www.elsev ier.com/locate /injury