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Cartilage lesions can be treated with HA-based scaffold with BMAC
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Cartilage defects in the knee are frequently encountered during arthroscopic procedures; however, there are limited treatment options that can be used to regenerate durable repair tissue. Due to their simplicity, marrow stimulation techniques for cartilage repair, such as microfracture, have often been considered for preferential use, despite the numerous clinical outcome studies that have failed to demonstrate long-term benefit, particularly in larger cartilage lesions.
Autologous chondrocyte implantation (ACI) techniques have demonstrated good long-term clinical outcomes and the ability to regenerate durable cartilage repair tissue. Commonly cited disadvantages of ACI, however, include the excessive cost associated with this therapy and the requirement that patients undergo two separate surgical procedures.
Cartilage repair using hyaluronic acid-based scaffolding embedded with bone marrow aspirate concentrate (HA-BMAC) has been shown to provide durable repair for patients with a wide range of ages and in cases of multiple and large lesions, which is comparable to results expected in ACI procedures. Moreover, the HA-BMAC technique may be done as a one-step procedure that is performed arthroscopically or used to treat osteochondral lesions in the case of significant subchondral injury.
HA-BMAC surgical technique
The patient is positioned supine as is done for standard knee arthroscopy. The operative knee and the ipsilateral iliac crest are exposed. The knee is examined under anesthesia and a diagnostic arthroscopy is completed. Any concomitant pathology is identified and treated as indicated, and the location and characteristics of the cartilage lesion(s) are evaluated. High-grade cartilage lesions are prepared prior to cartilage repair by creating a well-shouldered defect surrounded by vertical cartilage walls. The defect base is debrided so that the calcified cartilage layer is removed without violating the subchondral end-plate. Specialized instruments, such as the Chondrectomes Set (ATMED-Z), may be used to assist with cartilage lesion preparation, particularly in cases of arthroscopic cartilage restoration procedures (Figure 1).
Source: Bogusaw Sadlik, MD, PhD
Source: Alberto Gobbi, MD
Graft preparation
Bone marrow aspirate (60-mL volume) is harvested from the ipsilateral iliac crest using a dedicated aspiration kit, such as the BMAC Harvest Smart PreP2 System (Harvest Technologies) and is centrifuged to prepare the bone marrow concentrate. The Hyalofast HA-based scaffold (Anika Therapeutics) is size-matched to the cartilage lesions. The BMAC is activated with Plateltex Act (Plateltex SRO) batroxobin enzyme to create a clot. BMAC is applied to the size-matched scaffold to create an adhesive and malleable HA-BMAC graft implant (Figure 2).
If the HA-BMAC graft is to be implanted arthroscopically, fluid must be completely drained from the joint space. Using a valveless cannula helps optimize visualization by equalizing pressure and aids atraumatic passage of the graft into the knee joint. An Arthroscopic Retracting System (ATMED-Z) may be used to better visualize the lesion and widen the working space (Figure 3). It is crucial to ensure complete visualization and access to the cartilage lesion if an arthroscopic approach is used. Otherwise, a small arthrotomy is the preferred approach. In addition to using a valveless cannula, a specialized scaffold insertion device and skid may be used in arthroscopic cases to assist with delivery and seating of the HA-BMAC graft (Figure 4). This type of instrument can be used for matrix-associated cell-based repair techniques. It allows for passage of the scaffold while minimizing trauma to the cellular elements, regardless of the use of mesenchymal stem cell isolates or autologous chondrocytes. Final positioning and orientation of the graft is done using non-toothed forceps or a similar instrument to avoid damaging the regenerative cells. HA-BMAC graft stability within the defect must be examined under direct visualization while mobilizing the knee through its range of motion to ensure security of implant fixation. Fibrin glue is applied to the periphery of the graft if greater stability is needed.
Figure 4. The scaffold insertion tool and accompanying skid are shown (a). The arthroscopic view shows how the cartilage lesion of the patella is prepared after fluid drainage and skid placement are done in preparation for graft insertion (b). The HA-BMAC graft is shown arthroscopically seated into the prepared cartilage defect (c).
Source: Bogusaw Sadlik, MD, PhD
Future directions
Cartilage restoration performed as a single-stage procedure has obvious benefits related to resource utilization and patient-related considerations, such as decreased morbidity and reduced socioeconomic impact. Clinical outcome data that examined HA-BMAC cartilage repair techniques have demonstrated success comparable to two-step procedures that used autologous chondrocytes over medium- and long-term follow-up. This technique can be applied to a wide range of cartilage lesion types and is readily used arthroscopically, in open procedures or in conjunction with bone grafting to reconstruct osteochondral lesions.
Click here to watch video of the procedure.
- References:
- Blasiak A, et al. Am J Sports Med. 2018;doi:10.1177/0363546517745489.
- Gobbi A, et al. Am J Sports Med. 2009;doi:10.1177/0363546509331419.
- Gobbi A, et al. Am J Sports Med. 2016;doi:10.1177/0363546516656179.
- Gobbi A, et al. Cartilage. 2015;doi:10.1177/1947603514563597.
- Gobbi A, et al. Knee Surg Sports Traumatol Arthrosc. 2014;doi:10.1007/s00167-013-2676-8.
- Gobbi A, et al. Knee Surg Sports Traumatol Arthrosc. 2017;doi:10.1007/s00167-016-3984-6.
- Gomoll AH, et al. Am J Sports Med. 2014;doi:10.1177/0363546514523927.
- Sadlik B, et al. Arthrosc Tech. 2014;doi:10.1016/j.eats.2013.09.010.
- Sadlik B, et al. Arthrosc Tech. 2017;doi:10.1016/j.eats.2016.10.023.
- Whyte GP, et al. Arthrosc Tech. 2016;doi:10.1016/j.eats.2016.04.020.
- Whyte GP, Gobbi A. Biologic knee arthroplasty for cartilage injury and early osteoarthritis. In: Gobbi A, Espregueira-Mendes J, Lane J, Karahan M., eds. Bio-orthopaedics. Berlin, Germany: Springer; 2017:517-525.
- For more information:
- Alberto Gobbi, MD, can be reached at Orthopaedic Arthroscopic Surgery International Bioresearch Foundation, Via Amadeo 24, Milan 20133, Italy; email: gobbi@cartilagedoctor.it.
- Katarzyna Herman, MD, can be reached at Orthopaedic Arthroscopic Surgery International Bioresearch Foundation, Via Amadeo 24, Milan 20133, Italy; email: fellow@oasiortopedia.it.
- Bogusaw Sadlik, MD, PhD, can be reached at Biological Joint Reconstruction Department, St. Luke’s Hospital, Bielsko-Biala, Poland; email: sadlik@lukasza.pl.
- Graeme P. Whyte, MD, MSc, FRCSC, can be reached at Cornell University, Weill Medical College; New York Presbyterian Hospital/Queens, 56-45 Main St., New York, NY 11355.
Disclosures: Gobbi reports he is a scientific consultant for Anika Therapeutics. Sadlik reports he is a consultant/advisor for ATMED-Z. Herman and Whyte report no relevant financial disclosures.