AMIC—Autologous Matrix-Induced Chondrogenesis Technique in Patellar Cartilage Defects Treatment: A Retrospective Study with a Mid-Term Follow-Up

Abstract

Background: Knee cartilage defects can be retrieved in 60% of patients undergoing knee arthroscopy, especially in the patellofemoral joint. Different techniques have been proposed to treat patellar defects, although most of them are associated with short-term results. In this study Autologous Matrix Induced Chondrogenesis (AMIC), combining subchondral microfractures with a collagen membrane (type I and III collagen), was used in the treatment of isolated patellar cartilage defects. Methods: Twenty-four patients were enrolled in this retrospective study. Subjective-International Knee Documentation Committee (IKDC), Visual Analog Scale for Pain (VAS), and Kujala score were collected at 1, 3, 6, and 12 months after surgery, whereas the Tegner Activity Level Scale was determined preoperatively and at final follow-up (final-FU). The same postoperative management and rehabilitation protocol was adopted for all the patients. Results: Fourteen patients met the inclusion–exclusion criteria and were evaluated at a mean final-FU of 68.2 months (range 25.4–111.2). At 12 months, Kujala, IKDC, and VAS scores significantly increased in comparison to the preoperative assessment, whereas no statistically significant differences were reported between 12 months and final follow-up. Conclusion: This study demonstrated very good results throughout the follow-up, also in sports patients. The AMIC technique, together with an adequate rehabilitation protocol, can be considered as a reliable one-step alternative for the treatment of large isolated patellar cartilage defects.

Autologous Matrix-Induced Chondrogenesis (AMIC) for Isolated Retropatellar Cartilage Lesions: Outcome after a Follow-Up of Minimum 2 Years

“…A more recent study by Tradadi el al. 27 analyzing 14 patients reported very good results throughout the followup period with a mean of 68.1 months. While the mean Kujula score at final follow-up was relatively high with a mean score of 87.7 (vs. 71.3 in the current study), this study excluded patients with uncorrected lower limb malalignment, uncorrected patellar instability, previous cartilage surgery, trochlear dysplasia, and diffuse patellar bone edema.…”

“…So far, clinical results of AMIC for retropatellar cartilage lesions have only been reported in small case series, studies with short-term follow-up or as a part of studies investigating AMIC for the entire knee joint without thorough subanalysis. [23][24][25][26][27]50 D'Hollander et al 25 reported a case-series of 10 patients after AMIC for PF cartilage lesions with a follow-up of 24 months showing significant clinical improvement. Functional outcomes, however, were lower compared with the current study with a reported mean postoperative Kujula score of 59.8 versus 71.3 and total KOOS of 243.9 versus 343.4.…”

“…So far, clinical results of AMIC for retropatellar cartilage lesions have only been reported in small case series, studies with short-term follow-up or as a part of studies investigating AMIC for the entire knee joint without thorough subanalysis. 23 - 27 , 50 …”

“…[20][21][22] However, results of AMIC for retropatellar cartilage lesions are only reported in small case series or are embedded in studies investigating AMIC for tibio-and patellofemoral lesions missing thorough subanalysis. [23][24][25][26][27] Furthermore, evidence of factors influencing the outcome after retropatellar AMIC is lacking, especially the effect of recently determined risk factors for PF cartilage lesions, including trochlear dysplasia, patella alta, and excessive lateral tilt remains unknown. 9 The purpose of this study was therefore to report the clinical outcome of AMIC for isolated focal retropatellar cartilage lesions and to evaluate the influence of PF anatomy.…”

Management of Patellar Chondral Defects with Autologous Matrix Induced Chondrogenesis (AMIC) Compared to Microfractures: A Four Years Follow-Up Clinical Trial

“…Of them, up to 37% are located in the patellar facets [ 36 , 37 , 38 , 39 ]. Previous studies concerning patients treated for patellar chondral defects with autologous chondrocyte implantation (ACI) reported acceptable clinical results [ 35 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ]. However, in these studies the patellofemoral joint was mainly treated along with the femorotibial joint, and primary and revision settings were not considered separately [ 23 , 24 , 25 , 26 ].…”