Introduction

Cartilage injuries, historically challenging to treat, have seen significant advancements with techniques like Autologous Matrix-Induced Chondrogenesis (AMIC). AMIC, which uses a type I and III collagen membrane to stabilize the bone marrow clot formed during microfracture procedures, has proven effective in cartilage repair. More recently, the integration of adipose-derived mesenchymal stem cells (AD-MSCs) has enhanced these repairs. This study presents the Lipo -AMIC technique, an adaptation of AMIC that incorporates microfragmented adipose tissue graft processed using the Lipogems® system for the treatment of focal, full-thickness knee cartilage lesions.

Technique
The Lipo -AMIC begins with a thorough clinical evaluation, including imaging studies to assess the extent of the lesion and any associated malalignment. Surgical correction is considered if the malalignment exceeds 2º to 3º. During the procedure, adipose tissue is harvested from the patient’s abdomen or flanks via lipoaspiration, then processed using the Lipogems® system to isolate the stromal vascular fraction (SVF), which is rich in AD-MSCs. This adipose graft, characterized by high viscosity, is combined with the Chondro-Gide® membrane to enhance cartilage repair. Arthroscopic evaluation should be made and treatment of any concomitant lesions, followed by exposure of the chondral lesion through a medial parapatellar mini-arthrotomy. The lesion is meticulously prepared by removing the calcified cartilage layer without disturbing the subchondral bone. A mold of the lesion is created, and the Chondro-Gide® membrane is cut to fit the defect precisely. The membrane is pre-soaked with the adipose tissue graft, then positioned over the lesion, and secured with sutures and fibrin glue to ensure stability. The knee is flexed and extended to assess the repair before completing the procedure.

Discussion

Lipo -AMIC technique represents a significant advancement in treating full-thickness cartilage lesions by increasing the number of AD-MSCs within the lesion through the use of a microfragmented adipose tissue graft. The membrane acts as both a scaffold and containment for the graft, promoting a favorable environment for tissue regeneration. Early clinical outcomes from similar procedures show significant improvements in patient-reported outcome measures (PROMs) and imaging studies, with minimal complications reported. The use of AD-MSCs in cartilage repair has gained substantial support due to their chondrogenic potential and paracrine activity, which are critical for tissue repair and regeneration. The ease of obtaining these cells through lipoaspiration, combined with their ability to enhance repair outcomes, makes them an attractive option. The Lipo -AMIC technique builds on AMIC principles while introducing modifications that improve the effectiveness of the graft. Studies have demonstrated the safety and efficacy of AD-MSCs. For instance, Sciarretta et al. reported significant and sustained improvements with the original Lipo -AMIC technique over a 5-year follow-up.

Conclusion

The modifications proposed in this Lipo-AMIC technique offers a promising, single-stage solution for full-thickness knee cartilage lesions. This procedure provides a feasible, safe, and potentially superior approach to cartilage repair. Further research is needed to validate these findings and assess long-term outcomes.