Long-term results of reconstructing the joints' articular surface in the knee and ankle with the surgical diamond instrumentation (SDI).

PURPOSE: The surgical diamond instrumentation (SDI), a precise wet-grinding technology, promised contact healing of press-fit inserted bone and even hyaline cartilage, lacks medium- and long-term results. This retrospective study was conducted to identify risk factors associated with the failure of the technique and the subjective patient outcome. METHODS: All patients treated for cartilage defects of the knee or ankle joint using the SDI technology between 2000 and 2012 with a follow-up > 1 year were included. Patients with general joint diseases or joint-related procedures, except for corrective osteotomies, were excluded. A standardized questionnaire (EQ-5D) and a questionnaire-based patient-reported outcome survey were used. Descriptive statistics were applied. A multivariate analysis examining risk factors for joint failure was performed. A p value < 0.05 was considered to indicate significant differences. RESULTS: 87 patients with autologous osteochondral transplantation (68 knee, 19 ankle) were included. The median age was 53 years (IQR 37.5-63.0 years) for knee and 36 years (IQR 27.5-54.0 years) for ankle joints. 57.9% of knee and 55.6% of ankle patients were female. Nine patients (8 knee, 1 ankle) had received arthroplasty. 93.3% of knee and 83.3% of ankle patients had an excellent function or minor disabilities. 73.3% of knee and 64.7% of ankle patients did not require pain medication. The mean EQ-5D score was 0.84 for knee and 0.77 for ankle. Patients with higher age were more likely to receive arthroplasty (p = 0.022). CONCLUSIONS: The SDI technique provides promising results with excellent joint survival rates and satisfying patient-reported outcomes. Failure of the technique might be associated with higher age.