ABSTRACT
To introduce the surgical procedure of orthopaedic robot-assisted vascularised fibular grafting for the treatment of ANFH and report the short-term result. Methods From September, 2016 to November, 2018, 17 patients (21 hips) with ANFH had undergone robot-assisted free fibular grafting. There were 14 males and 3 females, of which, 8 cases were associated with the right side, 5 cases the left side, and 4 cases with both sides. The average age was 35 (ranged from 17 to 55) years. There were 7 patients suffered from idiopathic ischemic necrosis of femoral head, 4 patients who had cannulated screws fixed after a femoral neck fracture, 4 patients who had a history of alcohol consumption, 1 patient who had taken corticosteroids for 6 months to treat nephritis, and 1 patient who had a history of alcohol consumption and had also taken corticosteroids. Seventeen hips were in Ficat stage II, and 4 hips were in Ficat stage III. The orthopaedic surgical robot workstation was used to plan the entry point and target of the guide pin during the operation, to place a cannula in the optimal position. Then a bone window was created and the fibula was placed into the bone tunnel.Using fluoroscopy to monitor each step of the procedure and verify the position of the fibula. Finally, the vessels were anastomosed. The patient remain in bed completely for a week with the use of vasodilator. The follow-up was accomplished with phone call and outpatient clinic, and Harris score was evaluated. Results All 21 surgical procedures were successful. The guide pins and fibula were accurately placed according to the robot’s plan, and the tips of the fibula were placed at the centre of the load-bearing region of the femoral heads, 4 to 6 mm from the articular surface. Conventional anticoagulant, anti-infective therapy was performed after the pro-cedure. Ten patients were followed-up postoperatively more than 1 year, with an average of 15 (from 12 to 24) months. The function of the hip joint recovered smoothly for 9 patients.Frontal and lateral X-ray and CT scans showed that the tips of the fibula were placed at the centre of the load-bearing region, 4 to 6 mm from the articular surface.One patient suffered from bilateral femoral head necrosis and the right side recovered smoothly after operation.However, joint move-ment was restricted for the left hip and the pain was significant.An arthroscopic examination was performed 1 month after the operation and did not identify any problems such as intraarticular incular infection or articular surface of the femoral head was protruded by the tip of the fibula.The symptoms were alleviated after removing the osteophytes at the rim of the acetabulum.The Harris score was 62.4±13.6 before operation, and 84.5±4.5 at the last time of followed-up after opera-tion.The difference in Harris scores was statisticly significant (P＜0.05). Conclusion With the assistance of an or-thopaedic robot system, the guide pin can be accurately positioned, thereby allowing the tip of the fibula to be inserted in-to the optimal anatomical position and maximising its mechanical efficacy.In theory, it is the best choice for performing fibular bone transplantation in ANFH.And the early effect of treatment is good.
ABSTRACT
Objective To evaluate the feasibility,technique and preliminary clinical results of the intraoperative three-dimensional (3-D) computer navigation system assisted free vascularized fibular grafting for the treatment of osteonecrosis of the femoral head.Methods From October 2010 to April 2013,14 patients (18 hips) with osteonecrosis of the femoral head were treated by free vascularized fibular graft transfer,assisted by intraoperative3-D computer navigation system.Of 18 hips,8 were classified as stage Ⅱ ;6 as stage Ⅲ,4 as stage Ⅳ according to Steinberg system.The entire procedures were visualized and guided by the 3-D navigation system,including location of optimal entry point,exploration of the field,excision of the necrotic bone tissues,and the fibular grafting transfer with vessel anastomosis.The follow-up records included the results of X-ray,the Harris score of the hip,and the complications.Results Operations of all 14 patients (18 hips) were smooth and successful with patent vessel and umcompromised grafts evidenced by ECT scan at day 7 postoperatively.Postoperative X-ray confirmed the complete eradication of necrotic focuses with surrounding calcified bone and the accurate positioning of fibular grafts.The mean follow-up period was 23.6 months (8-29 months).Harris scores significantly improved from 57.5 ± 14.5 before operations to 87.5 ±2.5 after,with 6 hips' scores classified as Excellent,and 11 as Good.X-ray obtained more than 1 year after operation suggested improvement was achieved in 15 hips.Conclusion Intraoperative 3-D computer navigation system has multiple merits in assisting free vascularized fibular grafting for the treatment of osteonecrosis of the femoral head,including clear anatomic structure,better accuracy,less damage,and reliable functional recovery,which imply it is a highly applicable approach.