Satellite Rod Fixation around Rod-fracture Area in Revision Surgery after Three-column Osteotomy for Severe Kyphoscoliosis.

OBJECTIVE

Three-column osteotomy (3CO) is considered valuable and increasingly utilized in the surgical treatment of severe spine deformity while associated with high implant-related complications and revision risks. This study aims to evaluate the feasibility and clinical outcomes of satellite rod fixation used around the rod-fracture area in revision surgery due to rod fracture after 3CO.

METHODS

Twenty-five patients applying satellite rod fixation in revision surgery from August 2012 to May 2016 were retrospectively reviewed as the SR group. Patients undergoing revision surgery with traditional strategy after 3CO due to rod-fracture were selected as the TR group. Cobb angle, distance between C plumb line and center sacral vertical line (C PL-CSVL), global kyphosis (GK) and sagittal vertical axis (SVA) were assessed. Patients were required to fulfill the Scoliosis Research Society-22 questionnaire (SRS-22) at pre-revision and the last follow-up. The paired t test was used to analyze the difference among pre-revision, post-revision and last follow-up.

RESULTS

There was no statistical difference in terms of age, gender, body mass index (BMI), fusion level at 1st surgery, and follow-up period between SR and TR group (all P > 0.05). The operation time (1.5 ± 0.7 h vs 3.2 ± 0.9 h, P < 0.001) and intraoperative blood loss (178 ± 51 mL vs 324 ± 96 mL, P < 0.001) were significantly higher in the TR group. Patients in both groups obtained obvious deformity correction after revision surgery. For patients in SR group, the coronal Cobb angle significantly improved from 27.9 ± 21.5° at pre-revision to 21.8 ± 16.6° at post-revision (P = 0.034). The C PL-CSVL decreased from 22.6 ± 14.3 mm to 21.3 ± 10.9 mm (P = 0.719). Similarly, improvement was attained in post-revision GK (25.8 ± 17.0° vs 20.2 ± 15.1°, P = 0.061). SVA was corrected from 35.6 ± 33.9 mm to 30.8 ± 24.3 mm after revision (P = 0.182). At the last follow-up, no significant correction loss was observed in both coronal and sagittal parameters (all P > 0.05). All patients responded to the SRS-22 questionnaire and all the domains showed improvements in different levels. As compared to the TR group, the SR group had significantly better pain and management satisfaction scores (all P < 0.05). Additionally, there was no reoccurrence of implant failure during follow-up and all patients achieved solid bony fusion in SR group.

CONCLUSION

Satellite rod fixation around rod-fracture area is indicated for patients in the requirement of revision surgeries due to rod fracture after 3CO. Compared with traditional revision strategies, revision surgery with satellite rods, if patients are selected adequately, is a simpler procedure with less intraoperative blood loss and shorter operating time.