A novel precision micro-drilling technique for treating osteochondral lesions of the talus with superior cartilage regeneration and early rehabilitation compared with microfracture: a randomized controlled study with 2-year follow-up.

Background: Arthroscopic microfracture (MF) is currently the most widely used surgical treatment for osteochondral lesions of the talus (OLTs), but poor cartilage regeneration and prolonged rehabilitation are the focus of improvement. This study aimed to conduct a novel procedure, subtle and precise osteo-drilling for the recovery of talus (SPORT surgery) with self-designed instruments and compare its clinical outcomes to the MF for OLTs. The novel procedure has the potential to address certain limitations of MF, including the significant subchondral bone destruction and restricted drilling position. Study design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 56 patients with OLTs who underwent surgical treatment from September 2021 to August 2022 were randomly assigned to the MF group or the SPORT group. For the SPORT group, a novel high elastic K-wire with a 1.2 mm diameter was used to drill subchondral bone holes with 10 mm depth through a curved guide. Clinical assessments were conducted by using VAS (Visual Analog Scale), AOFAS (American Orthopaedic Foot & Ankle Society) score, FAAM-ADL (Foot and Ankle Ability Measure-Activities of Daily Living) score, and SP (Foot and Ankle Ability Measure-Sports) score. MRI evaluation included relative signal intensity of subchondral bone marrow edema (RSI-SBME), volume of the subchondral bone marrow edema (V-SBME), and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. The differences in clinical outcomes and imaging results between the two groups were compared at pre-surgery, postoperative 3, 6, 12, and 24 months. Results: Both the MF and SPORT groups showed significant improvement in all clinical outcomes. At 3- and 6-month post-op, the clinical outcomes of the SPORT group were significantly better than those of the MF group (improved 44.6 % and 32.2 % at 3- and 6-month postoperative for FAAM-SP, P ≤ 0.001). The percentage of patients in the SPORT group who met the MCID of FAAM-SP is significantly higher than in the MF group at 3-month (P = 0.007) and 6-month (P = 0.005) postoperative. Besides, the SPORT group achieved better MOCART scores than the MF group at all follow-ups (P ≤ 0.002). After 12 months, there was no significant difference in clinical outcomes between the two groups. Conclusion: The novel device-guided SPORT surgery has significant advantages over conventional MF technology in terms of early postoperative return to sport and long-term cartilage regeneration in OLT patients. The translational potential of this article: The SPORT surgery and the novel guided subchondral bone drilling instruments have excellent translational potential in sports medicine as an alternative to replace traditional MF techniques for OLTs and can be extended to cartilage repair in other joints, such as the knee and shoulder.