What did the study look at?
Damage affecting both the cartilage and the underlying bone on the upper surface of the talus, the bone forming the ankle joint, is called an osteochondral lesion. The authors note that, because cartilage cells have a low capacity to regenerate, treating these lesions remains challenging.
Two arthroscopic methods were compared: nanofracture, in which deep holes are made in the bone with a 1 mm needle, and a one-stage method in which bone marrow taken from the pelvis is concentrated (bone marrow aspirate concentrate) and placed in the lesion with a hyaluronic acid-based cell-free scaffold. The aim was to compare early clinical and radiological results.
How was it done?
- Patients with focal osteochondral lesions of the talus treated between January 2012 and January 2015 were evaluated retrospectively; 98 met the criteria.
- Patients were aged 18–45, had a body mass index under 30 and lesions larger than 1.5 cm² (Outerbridge grade 3–4).
- Operations were performed by two surgeons; one preferred the scaffold with bone marrow concentrate (Group 1, 46 patients) and the other nanofracture (Group 2, 52 patients).
- In Group 1, all patients underwent microfracture before the scaffold was applied.
- Outcomes were compared using the AOFAS ankle score, a pain score (VAS, 0–10) and the MOCART score, which assesses cartilage repair tissue on 3 Tesla MRI.
What did it find?
- The groups were similar in age, body mass index, lesion size and depth, and follow-up (mean 42.2 and 40.1 months).
- Mean AOFAS score was 93.7 in Group 1 and 86.1 in Group 2 (p=0.028).
- Mean VAS score was 1.3 in Group 1 and 0.8 in Group 2; the difference was statistically significant (p=0.046).
- Mean MOCART score was 82 in Group 1 and 73 in Group 2 (p=0.041).
- On MRI, repair tissue in Group 1 was compatible with hyaline-like cartilage, with complete integration in 82% of patients. In Group 2, repair tissue was considered fibrous in all patients, with complete integration in 66%.
- No major complications occurred; two patients in Group 1 developed a superficial infection treated with oral antibiotics.
The authors' conclusion
The authors conclude that both nanofracture and the hyaluronic acid-based cell-free scaffold with bone marrow concentrate are beneficial for talar osteochondral lesions, and that better clinical and radiological results can be obtained with the scaffold and bone marrow concentrate than with nanofracture.
Limitations
- Patient numbers and follow-up were limited, and the design was retrospective.
- Scores were compared only at final follow-up; there were no preoperative clinical scores.
- Cartilage structure was assessed by MRI rather than biopsy. The authors call for larger prospective studies with control groups and longer follow-up.
Reference
Tahta M, Akkaya M, Gürsoy S, Isik C, Bozkurt M. Arthroscopic treatment of osteochondral lesions of the talus: Nanofracture versus hyaluronic acid-based cell-free scaffold with concentration of autologous bone marrow aspirate. Journal of Orthopaedic Surgery (Hong Kong). 2017;25(2):2309499017717870. Published under a Creative Commons Attribution-NonCommercial 4.0 (CC BY-NC 4.0) licence.
Free full text: Journal of Orthopaedic Surgery (SAGE)
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