Matrix-associated stem cell transplantation (MAST) in chondral defects of foot and ankle is effective
Introduction
The optimal treatment for chondral defects at foot and ankle is debatable. The current options are distraction, debridement, abrasion, microfracture, antegrade or retrograde drilling, mosaicplasty or osteochondral autograft transfer system (OATS), autologous chondrocyte implantation (ACI), matrix-induced autologous chondrocyte implantation (MACI), autologous matrix-induced chondrogenesis (AMIC), allologous stem cell transplantation, or allograft bone/cartilage transplantation [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47]. Methods like debridement, abrasion, microfracture and retrograde drilling have a limited complexity, expense and morbidity [32], [33], [42]. However, these methods do not create a normal cartilage but fibrous tissue, or at best fibrous cartilage [32], [38], [42]. Retrograde drillings might maintain the existing cartilage but cannot create any new cartilage [42]. The effect of distraction on the cartilage remains debatable [44], [45], [46], [47]. A positive effect on the cartilage texture could be shown in the animal experiment but not in humans so far [47]. Mosaicplasty or OATS have the advantage of transferring normal cartilage and showed good results [19], [21], [23], [31], [34], [35], [36]. Considerable disadvantages such as morbidity at the donor site (mostly the knee, up to 30%), mismatch of the cartilage thickness and shape between donor and recipient site, and cumbersome technical issues like often necessary malleolar osteotomies limited the indications and dissemination of these techniques [19], [21], [31]. Furthermore, OATS did not show better results than microfacture alone which is much easier and quicker to do, and without donor site morbidity [33]. Cartilage cell transplantation techniques (ACI, MACI) utilize autologous cultured chondrocytes that were harvested during an earlier surgical procedure [1], [8], [11], [12], [18], [20], [24], [30], [38]. The results of these techniques have also been favorable [1], [8], [11], [12], [18], [20], [24], [30], [38]. However, the disadvantages are enormous. First, an additional surgical procedure for harvesting the cells is needed, and second, the cultivating process is costly and not covered by the health insurances in most countries. ACI, using chondrocytes in fluid form alone, is extremely difficult to perform because the fluid has to be fixed within the cartilage defect which is for example done with periosteal flaps that are sutured above and/or below (sandwich technique) the chondrocyte-fluid [24], [30]. MACI, using a scaffold matrix, is a useful modification to keep the chondrocytes in the defect and made ACI obsolete in the opinion of most experts [1], [11], [20]. Still, the most significant disadvantages like two surgical procedures and high cost could not be justified by the results that were clinically not superior to debridement methods [1]. However, the potential of these methods, especially MACI, could be shown in MRI and histological studies in which more physiological cartilage than with debridement or microfracture has been verified [1]. This called into question if “cells” have to be harvested during an earlier surgery. AMIC is using local cells from the underlying bone marrow, cells from the peripherial blood [10], [13], [22]. The clear advantages in comparison with ACI and MACI are the single surgery and much lower cost [10], [13], [22]. The latest results of these single stage procedures are comparable to the “real” chondrocyte transplantations, and seem to be more promising overall [10], [13], [22]. Questionable are the type of cells used, and the techniques for the application and fixation. Some techniques do just inject centrifuged peripheral blood into joints whereas other techniques use centrifuged bone marrow content implanted on hyaluronic acid membranes [10], [13], [22]. One step further is the use of “real” stem cells (CD 34+) that are currently available as allograft [43]. The use of allograft has several disadvantages such as potential infection and incompatibility (host versus graft and graft versus host). Other unsolved problems are the dosage and control of the stem cell performance or function. Still, the potential of these pluripotent cells (especially when autologous) seems to be the future for cartilage repair (see below). This potential calls especially into question if allologous bone/cartilage transplantation is really an useful option for the further future, or just a temporary trend. The results of these allograft techniques are not convincing but they are mostly used for large cartilage and bone defects that are not comparable with just superficial defects limited to the cartilage [6], [9], [14], [17]. Based on these considerations, comparable techniques with bone plugs or hemiprosthesis seem also to be seminal developments [15].
Matrix-associated stem cell transplantation (MAST) is a modification of AMIC with a potentially higher concentration of stem cells in the implanted matrix. The aim of the study was to assess the feasibility and 2-year-follow-up of MAST in chondral defects of the ankle and additionally in other joints of the foot.
Section snippets
Technique
MAST was performed as single open procedure associated with other procedures (Table 1). Stem cell-rich blood was harvested during the procedure from the ipsilateral pelvic bone marrow with a Jamshidi needle (10 mm × 3 mm, Cardinal, Dublin, OH, USA) and a special syringe (Arthrex-ACP®, Arthrex, Naples, FL, USA) through a stab incision. The syringe was centrifuged (10 min, 1500 rotations per minute (RPM)). The supernatant was used to impregnate a collagen I/III matrix (Chondro-Guide®, Geistlich,
Results
Twenty-six chondral defects in 25 patients were included in the study. The age of the patients was 33 years on average (range, 16–48 years), 18 (72%) were male. 18 patients (72%) stated that they performed sports at least at recreational level before having symptoms, and 6 (24%) at the time at surgery. Table 2 shows cause and injury mechanism. The most common cause was sports-related trauma (n = 11, 42%), and the most common injury mechanism was multiple sprains at the ankle (n = 10, 38%). The VAS
Discussion
There are numerous treatment options for cartilage defects of the foot and ankle, of which the majority has been applied of the talus [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47]. This implies that none of the options described is optimal. Furthermore, the use of these
Conflict of interest
None of the authors or the authors’ institution received funding in relation to this study.
References (54)
- et al.
Assessment of articular cartilage repair tissue after matrix-associated autologous chondrocyte transplantation or the microfracture technique in the ankle joint using diffusion-weighted imaging at 3 Tesla
Osteoarthritis and Cartilage
(2012) - et al.
Cartilage repair evolution in post-traumatic osteochondral lesions of the talus: from open field autologous chondrocyte to bone-marrow-derived cells transplantation
Injury
(2010) - et al.
Validity of T2 mapping in characterization of the regeneration tissue by bone marrow derived cell transplantation in osteochondral lesions of the ankle
European Journal of Radiology
(2011) - et al.
Effectiveness of composite bone graft substitute plugs in the treatment of chondral and osteochondral lesions of the talus
Journal of Foot and Ankle Surgery
(2010) - et al.
Osteochondral lesions of the talus: randomized controlled trial comparing chondroplasty, microfracture, and osteochondral autograft transplantation
Arthroscopy
(2006) - et al.
Bone-cartilage transplantation from the ipsilateral knee for chondral lesions of the talus
Arthroscopy
(2005) The mosaicplasty technique for osteochondral lesions of the talus
Foot and Ankle Clinics
(2003)- et al.
Osteoarticular grafts in the treatment of OCD of the talus: mosaicplasty versus autologous chondrocyte transplantation
Foot and Ankle Clinics
(2002) - et al.
The diagnosis and management of osteochondral lesions of the talus: osteochondral allograft update
Arthroscopy
(2003) - et al.
Ankle arthrodiastasis
Clinics in Podiatric Medicine and Surgery
(2009)