Enhanced microfracture techniques in cartilage knee surgery: Fact or fiction?

Abstract

The limited intrinsic healing potential of human articular cartilage is a well-known problem in orthopedic surgery. Thus a variety of surgical techniques have been developed to reduce joint pain, improve joint function and delay the onset of osteoarthritis. Microfractures as a bone marrow stimulation technique present the most common applied articular cartilage repair procedure today. Unfortunately the deficiencies of fibrocartilaginous repair tissue inevitably lead to breakdown under normal joint loading and clinical results deteriorate with time. To overcome the shortcomings of microfracture, an enhanced microfracture technique was developed with an additional collagen I/III membrane (Autologous, Matrix-Induced Chondrogenesis, AMIC(®)). This article reviews the pre-clinical rationale of microfractures and AMIC(®), presents clinical studies and shows the advantages and disadvantages of these widely used techniques. PubMed and the Cochrane database were searched to identify relevant studies. We used a comprehensive search strategy with no date or language restrictions to locate studies that examined the AMIC(®) technique and microfracture. Search keywords included cartilage, microfracture, AMIC(®), knee, Chondro-Gide(®). Besides this, we included our own experiences and study authors were contacted if more and non published data were needed. Both cartilage repair techniques represent an effective and safe method of treating full-thickness chondral defects of the knee in selected cases. While results after microfracture deteriorate with time, mid-term results after AMIC(®) seem to be enduring. Randomized studies with long-term follow-up are needed whether the grafted area will maintain functional improvement and structural integrity over time.

Matrix-Associated Autologous Chondrocyte Implantation

“…17 This is in accordance with the published data about an enhanced MFx technique at midterm follow-up. 18 In a prospective study by Mithoefer et al, 19 a lower body mass index correlated with higher scores for the activities of daily living and Short Form-36 after MFx in 48 symptomatic patients with isolated full-thickness articular defects in the knee joint. Worst results were seen in patients with a body mass index >30 kg/m 2 .…”

Autologous chondrocyte implantation (ACI) for cartilage defects of the knee: A guideline by the working group “Clinical Tissue Regeneration” of the German Society of Orthopaedics and Trauma (DGOU)

“…Whether the marrow space opening is carried out classically as described by Steadman [27] with conical awls to penetrate the subchondral lamellae, or whether it is advantageous to turn back to the original drilling techniques, or to use newer techniques such as the nanofracture procedure, which is considered to allow the recruitment of cells with a better quality into the defect [28][29][30], is the subject of ongoing debate, and cannot be finally assessed at this time, since clinical evidence is still missing. Perforation and therefore injury of the subchondral bone plate are criticised by some authors [31].…”

Good clinical results with autologous matrix-induced chondrogenesis (Amic) technique in large knee chondral defects

“…The mean Lysholm score improved from 38.8 (±12.4) points preoperatively to 72.6 (±19.5) points at the last follow-up (p < 0.05). At the last follow-up, 76.2% of patients containing the MSCs maybe not stable enough to sustain the tangential forces of the knee [4], the consequent weakness of the final cartilaginous repair tissue may lead to its early breakdown under normal knee loading. The use of an exogenous scaffold (e.g.…”