First described and classified in 1959 by Berndt and Harty, osteochondral injuries (OCLs) of the talus bone can cause weight-bearing associated pain, loss of range of motion, and locked-in or unstable mechanical symptoms, leading to severe mobility impairments, and OCL has been proposed as a precursor to the early development of progressive osteoarthritis.
With the continuous exploration of the role of mesenchymal stem cells (MSCs), scholars have become interested in their role in cartilage repair, and early preclinical and clinical studies have shown benefits in improving symptoms and structure. Julien Freitag et al. reported a clinical trial of autologous AD-MSCs transplantation of ankle OCLs, which showed successful regeneration of hyaline cartilage on postoperative MRI.
The study included a 42-year-old man who presented with right ankle pain 13 years ago and then underwent chondroplasty curettage, periosteal graft surgery, activity modification, pharmacological analgesia, and physical**, but his condition did not improve. Routine radiographic evaluation on x-rays showed early talar osteoarthritis and the presence of OCL in the lateral talar dome (Figure 1), and active myeloedema was observed deep within the OCL sclerosis line.
With the informed consent of the patient, OCL curettage was performed first, and 25 mL of liposucate was collected from the patient, and the required AD-MSCs were obtained after isolation and culture, and the AD-MSCs were injected into the ankle joint cavity under local sedation. Received 20 million AD-MSCs at baseline;Repeat the same dose of AD-MSCS at 6 months;After 12 months of reexamination, incomplete cartilage regeneration was observed, and the patient underwent a final transplant of 50 million AD-MSCs.
RESULTS:Changes in foot and ankle disability index (FADI) score and International Cartilage Repair Society (ICRS) score:The FADI score increased from 61% at baseline to 91% at 24 months (see figure below), indicating significant improvement in clinical functioning;The ICRS score improved from 3 at 3 months to 1 at 24 months.
Changes in MRI imaging before and after transplantation:Three months after AD-MSCS transplantation, MRI imaging showed incomplete cartilage-like tissue at the OCL siteAt 8 months, MRI showed continued maturation of the cartilage-like tissue, but a continuous radiolucency of the medial border of the neocartilage and subchondral plate remainedAt 12 months, MRI showed continued tissue maturation;At 24 months, MRI showed that the OCL site had a strong hyaline cartilage filling regeneration and smooth integration with the surrounding natural cartilage (Figure 2).
MRI T2 Analysis:At 3 months, MRI T2 mapping analysis showed that the relaxation time value averaged 80 msec, with the best value recorded in the shallow region (mean 54 msec) and the larger value recorded in the deep region (mean 110 msec);The average improvement was 65 msec at 24 months, and the T2 value showed a value comparable to that in the natural cartilage (Figure 3 and Table 3). Overall T2 relaxation time values improved throughout the follow-up period.
Adverse events:No significant adverse events were noted throughout the follow-up, and patients experienced mild self-limiting discomfort after each transplant of AD-MSCs, which lasted for 1 week with the use of ice and simple painkillers.
In summary, autologous AD-MSCS** combined with arthroscopic curettage** ankle OCL has successfully achieved functional and structural improvement, and ** is well tolerated. It is understood that this is the first time that the use of this technology has been observed in the literature, and the structural results have been significantly improved compared to other well-researched and currently used technologies, indicating that AD-MSCS is a promising option.
References: Julien Freitag, James Wickham, Kiran Shah, Abi Teen effect of autologous adipose-derived mesenchymal stem cell therapy in the treatment of an osteochondral lesion of the ankle.doi:10.1136/bcr-2020-234595.