[Effect of robot navigation assisted core decompression combined with bone graft treatment of early stage osteonecrosis of the femoral head].

Objective: To evaluate the effects of orthopedic robot navigation system used in core decompression combined with bone graft surgery for osteonecrosis of the femoral head (ONFH).
Methods: A retrospective analysis was performed on 9 patients (16 hips) underwent core decompression surgery combined with bone graft treatment for early ONFH in ARCO Ⅱat Department of Osteoarthropathy, Yantaishan Hospital from June 2016 to February 2018.There were 7 males and 2 females, aged 44.6 years (range: 28-60 years). All surgery procedures were completed by the same doctor under the navigation of orthopedic surgery robot using the specific designed tools. The preoperative and postoperative Harris Hip Score and visual analogue score were compared and the time of intraoperative X-ray fluoroscopy was recorded.
Results: The mean follow-up period was (12.7±3.5)months (range: 6-18 months). Four cases of treatment failure were observed in 16 hips at the last follow-up and the hip survival rate was 12/16.In stage ARCO Ⅱa, Ⅱb and Ⅱc, the survival rate was 1/1, 2/2, and 9/13.The Harris Hip Score (88.3±1.9 vs.70.0±3.8, t=16.81, P=0.000) and visual analogue score (3.7±0.7 vs. 0.9±0.6, t=13.49, P=0.000) were improved significantly at the last follow-up compared with preoperative value. The total times of intraoperative X-ray fluoroscopy were 15.9±2.5, including 5.8±1.2 before the insertion of the guiding wire and 10.1±1.7 after the insertion of the guiding wire. Conclusions: The domestic orthopedic surgery robot can be applied successfully in the core decompression combined with bone graft surgery for ONFH . It is less invasive with less fluoroscopy time and better bone graft effects.