Convincing one-step cartilage regeneration with the combination of NanoFx® and Hyalofast®
NanoFx® and Hyalofast® offer a modern therapeutic concept for the treatment of chondral and osteochondral defects. Nanofracturing is a standardized procedure for recruiting mesenchymal stem cells (MSC) from the marrow cavity. Matrix-augmented cartilage regeneration with Hyalofast® promotes MSC differentiation through the biological activity of hyaluronic acid, supporting chondrogenesis. Thus, NanoFx® and Hyalofast® complement each other to form an optimal treatment concept for cartilage defects.
Standardized procedure
- Controlled depth of 9 mm and narrow 1 mm diameter
- Reusable instrument with sharp single-use needles
Superior bone marrow stimulation
- Increased stem cell yield due to deeper perforation
- Improved defect filling with a high proportion of type 2 collagen
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Easy and safe application
- Smooth and rapid perforation
- Facilitates the restoration of subchondral bone
Nanofracturing with NanoFx®
Microfracturing is increasingly being criticized as a treatment option for focal cartilage defects and, according to professional societies and cartilage experts, should only be used in exceptional cases. Nanofracturing offers an effective alternative for the treatment of chondral and osteochondral defects. NanoFx® is a system for bone marrow stimulation that provides a standardized procedure for nanofracturing. By deeply perforating the subchondral plate and the sub-articular cancellous bone, direct access channels to the marrow cavity are created, allowing mesenchymal stem cells (MSC) to infiltrate the cartilage defect. This bleeding, accompanied by the recruitment of MSC, is essential for cartilage regeneration. Through the 9 mm deep perforation achieved with NanoFx®, high yields of MSC can be obtained, promoting high-quality cartilage regeneration with a hyaline-like character. In addition, the 1 mm thin diameter helps preserve the subchondral plate and cancellous bone, aiming to support rapid healing and restoration of the subchondral bone.
Schematic comparison of microfracturing vs. nanofracturing with NanoFx®
The contemporary form of bone marrow stimulation
Comparison of nanofracturing with microfracturing and K-wire drilling
An in-vivo comparative study in adult sheep provides insight into the subchondral differences between three methods of bone marrow stimulation and their effects on trabecular bone structure.
(△) open trabecular channels; (▲) closed trabecular channels; microCT comparison: axial (top), sagittal (bottom)
Microfracturing: Trabecular wall thickness and density increase due to bone compression; limited number of open trabecular channels; canal edges with non-anatomical uniformity (left). Peripheral canal edges: crushed and dense bone deposits (right).
Nanofracturing: Trabecular wall thickness and density appear normal; high number of open trabecular channels; anatomical irregularities of the canal edges intact (left). Peripheral canal edges: porous, fragmented bone deposits (right).
1 mm K-wire: Trabecular wall thickness and density are nearly normal; limited number of open trabecular channels; canal edges with non-anatomical uniformity (left). Peripheral canal edges: crushed and dense bone deposits (right)
It was shown that microfracturing with a conventional awl (diameter approx. 2.5 mm, images left) resulted in superficial perforations with compression of the cancellous bone. In this procedure, the number of open trabecular channel accesses is limited, and both channel depth and diameter are highly variable and depend on the user’s technique and the instruments used.
K-wire drilling (diameter 1 mm, images right) produced straight canal walls, whereas open trabecular channels were limited. Motor-assisted drilling can generate rotational heat and press the drilled tissue against the canal edges. This leads to the closure of trabecular channel openings. The diameter of the wire is standardized, but the depth of the procedure is highly variable, as it must be visually controlled.
Nanofracturing with NanoFx® (middle images) achieved deep perforations of the cancellous bone with a high number of open trabecular channels without generating rotational heat. In contrast to microfracturing, nanofracturing is standardized with a controlled depth of 9 mm and a diameter of 1 mm, increasing the comparability and reproducibility of this procedure.
Fast and easy application
The NanoFx® guide can be inserted into the defect arthroscopically or minimally invasively and does not require any specific incisions. With the sterile single-use needle, a sharp instrument is always available to perforate the subchondral plate. NanoFx® is easy to assemble and therefore quickly ready for use. Compared to microfracturing, the force of the hammer strike is optimally transferred to the 1 mm thin tip of the needle, meaning that even light taps are sufficient. Thanks to the integrated depth stop, the needle is always inserted in a controlled manner to a depth of 9 mm into the cancellous bone. Application of NanoFx®:
The NanoFx® guide is reusable and must be cleaned and sterilized after use.
Product: NanoFx® – instrument for bone marrow stimulation Items: NanoFx® guide, PleuriStik nitinol needle, thumb tab Approval: Medical device with CE marking Sterilization: Gamma sterilized Storage: Store dry
NanoFx® guide (e.g., knee, shoulder)
NanoFx® guide A-Curve (e.g., upper ankle joint)
More knowledge, more movement
Bone marrow stimulation for the recruitment of progenitor cells into the cartilage defect is a well-established therapeutic option in cartilage regeneration. Since the late 1980s, microfracturing has developed into the primary treatment choice due to its low cost, relatively low morbidity, and encouraging results as a first-line procedure for cartilage defects, especially in young and active patients (1–3).
Renewed interest in the effects on the subchondral bone shed new light on the limitations of microfracturing: shallow channels, wall compression, and an increase in trabecular wall thickness and density were observed via CT and histology (4–6). Chen et al. reported that deeper subchondral bone marrow stimulation resulted in better cartilage defect filling, more type II collagen, and less type I collagen compared to shallow bone marrow access (5). A study by Eldracher et al. (7) showed that 1 mm drill holes resulted in improved histology, cancellous bone restoration, and immunoreactivity toward type II collagen compared to 1.8 mm drill holes.
The non-standardized depth, diameter, and perforation density of microfracturing led to the development of a new method for perforating the subchondral plate (nanofracturing), which provides a standardized depth of 9 mm and a diameter of 1 mm.
Literature
- Kreuz PC, Steinwachs MR, Erggelet C, Krause SJ, Konrad G, Uhl M, Südkamp N. Results after microfracture of full-thickness chondral defects in different compartments in the knee. Osteoarthritis Cartilage. 2006 Nov;14(11):1119–25.
- Mithoefer K, Williams RJ 3rd, Warren RF, Potter HG, Spock CR, Jones EC, Wickiewicz TL, Marx RG. The microfracture technique for the treatment of articular cartilage lesions in the knee. A prospective cohort study. J Bone Joint Surg Am. 2005 Sep;87(9):1911–20.
- Steadman JR, Briggs KK, Rodrigo JJ, Kocher MS, Gill TJ, Rodkey WG. Outcomes of microfracture for traumatic chondral defects of the knee: average 11-year follow-up. Arthroscopy. 2003 May–Jun;19(5):477–84.
- Chen H, Sun J, Hoemann CD, Lascau-Coman V, Ouyang W, McKee MD, Shive MS, Buschmann MD. Drilling and microfracture lead to different bone structure and necrosis during bone-marrow stimulation for cartilage repair. J Orthop Res. 2009 Nov;27(11):1432–8.
- Chen H, Hoemann CD, Sun J, Chevrier A, McKee MD, Shive MS, Hurtig M, Buschmann MD. Depth of subchondral perforation influences the outcome of bone marrow stimulation cartilage repair. J Orthop Res. 2011 Aug;29(8):1178–84.
- Fortier LA, Cole BJ, McIlwraith CW. Science and animal models of marrow stimulation for cartilage repair. J Knee Surg. 2012 Mar;25(1):3–8.
- Eldracher M. et al. Small Subchondral Drill Holes Improve Marrow Stimulation of Articular Cartilage Defects. Am J Sports Med. 2014 Nov;42(11):2741–50.
